Title of Invention	"ADAPTIVE NEUTRAL SENSING"
Abstract	A method for controlling assisted shifting tn a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are Indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising: sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from sald vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said First maximum value, if said main transmission section was last determined to be in neutral; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section.

Title of Invention

"ADAPTIVE NEUTRAL SENSING"

Abstract

A method for controlling assisted shifting tn a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are Indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising: sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from sald vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said First maximum value, if said main transmission section was last determined to be in neutral; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section.

Full Text	- 1A - 98-TRN-092 ADAPTIVE NEUTRAL SENSING BACKGROUND OF THE INVENTION RELATED APPLICATIONS This application is related to the following co-pending applications, all assigned to EATON CORPORATION, the assignee of this application: 5 Serial No. 08/ [96-TRN-263] mailed 04/01/98 and titled RANGE SHIFT CONTROL Serial No. 08/ [97-TRN-561] mailed 04/01/98 and titled ADAPTIVE UPSHIFT JAW CLUTCH ENGAGEMENT CONTROL Serial No. 08/ [97-TRN-566] mailed 04/01/98 and titled 10 ENGINE FUEL CONTROL FOR COMPLETING SHIFTS IN CONTROLLER- ASSISTED, MANUALLY SHIFTED TRANSMISSIONS Serial No. 08/ [97-TRN-567] mailed 04/01/98 and titled DYNAMIC RANGE SHIFT ACTUATION Serial No. 08/ [98-TRN-067] mailed 04/01/98 and titled JAW 15 CLUTCH ENGAGEMENT CONTROL FOR ASSISTED, MANUALLY SHIFTED, SPLITTER-TYPE TRANSMISSION SYSTEM Serial No. 08/ [98-TRN-101] mailed 04/01/98 and titled ADAPTIVE SPLITTER ACTUATOR ENGAGEMENT FORCE CONTROL Serial No. 08/902,603 filed 08/07/97 and titled PARIALLY 20 AUTOMATED, LEVER-SHIFTED MECHANICAL TRANSMISSION SYSTEM Serial No. 08/ [97-rTRN-495] mailed 12/11/97 and titled ASSISTED LEVER-SHIFTED TRANSMISSION. 25 FIELD OF THE INVENTION The present invention relates to a control system/method for controlling automatically implemented and/or assisted shifting. In particular, the present invention relates to automatically implemented and/or assisted shifting in a transmission (such as a compound transmission having a main 30 section shifted by a manually opera ted shift lever or shift selector) as a 2 98 TRN-092 function of the sensed presence or absence of a main section neutral condition. More particularly, the present invention relates to controls for such shifting which determine if the main transmission section is in neutral or is engaged in response to sensed shift lever position and which will vary the shift lever positions at which a main section neutral condition is declared in response to sensed vehicle operating conditions. DESCRIPTION OF THE PRIOR ART Compound manually shifted mechanical transmissions of the range, splitter and/or combined range/splitter type are in wide use in heavy-duty vehicles and are well known in the prior art, as may be seen by reference to U.S. Pats. No. 4,754,665; 5,272,929; 5,370,013 and 5.390,561, 5,546,823; 5,609.062 and 5,642,643, the disclosures of which are incorporated herein by reference. Typically, such transmissions include a .IT main section shifted directly or remotely by a manual shift lever and one or more auxiliary sections connected in series therewith. The auxiliary sections most often were shifted by a slave actuator, usually pneumatically, hydraulically, mechanically and/or electrically operated, in response to manual operation of one or more master switches. Shift controls for such systems by be seen by reference to U.S. Pats. No. 4,455,883; 4,550,627; 4,899,607; 4,920,815; 4,974,468; 5,000,060; 5,272,931; 5,281,902; 5,222,404 and 5,350,561, the disclosures of which are incorpbraTecrrTerein by reference. Fully or partially automated transmission systems wherein a microprocessor-based electronic control unit (ECU) receives input signals indicative of various system operating conditions and processes same according to logic rules to issue command output signals to one or more system actuators are known in the prior art, as may be seen by reference to U.S. Pats. No. 4,361,060; 4,593,580; 4,595,986; 4,850,236; 5,435,212; 5,582,069; 5,582,558; 5,620,392; 5,651,292 and 5,679,096; 5,682,790; the disclosures of which are incorporated herein by reference. 3 98-TRN-092 These systems often used the sensed engaged or neutral condition of the transmission and/or transmission main section as an important control parameter. 5 SUMMARY OF THE INVENTION A preferred embodiment of the present invention involves a computer-assisted mechanical compound transmission system wherein the main section is shifted by a manually controlled shift lever operating in a predetermined shift pattern and the engine is fueled and/or the auxiliary 10 sections are shifted by actuators at least partially controlled by an ECU to enhance shifting. The ECU uses sensed and/or calculated inputs indicative of system operating parameters, such as operation of a splitter switch, position and/or rate of change of position of the shift lever, engaged gear ratio, engine speed, output shaft speed, clutch condition and/or throttle 15 pedal position, to assist shifting by controlling engine fueling and/or operation of the range and/or splitter shift actuators. In accordance with the present invention, the drawbacks of the prior art are minimized or overcome by the provision of a computer-enhanced, lever-shifted compound vehicular transmission system having a position 20 sensor for sensing shift lever position and control logic to determine main section condition as a variable function of such sensed position and logic for sensing/determining vehicle operating conditions and varying the shift lever positions at which main section neutral is declared as a function of vehicle operating conditions to enhance system performance. 25 Accordingly, it is an object of the present invention to provide ECU assistance for enhanced shifting of a mechanical compound transmission having a main section shifted by a manually operated shift lever. Another object of the present invention is to provide an improved computer-assisted transmission system, preferably including a compound 30 transmission, having a lever position sensor for determining a main section neutral condition and having logic for adaptively modifying the lever 4 98-TRN-092 positions considered to be an indication of transmission main section neutral as a function of sensed vehicle operating conditions. These and other objects and advantages of the present invention will become apparent from a reading of the following description of the 5 preferred embodiment taken in connection with the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic illustration of an ECU-assisted compound mechanical transmission system advantageously utilizing the range shifting 10 control of the present invention. Fig. 2 is a chart illustrating the shift pattern and representative numerical ratios for the transmission of Fig. 1. Fig. 3 is a schematic illustration of the structure of the compound mechanical transmission of Fig. 1. 15 Fig. 4 is a schematic illustration of a three-position splitter actuator for use with the transmission system of Fig. 1. Figs. 5A and 5B are schematic illustrations of a shift shaft position sensor mechanism for use in the system of Fig. 1. Fig. 6 is a schematic illustration, in flow chart format, of the control 20 of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT A computer-assisted (i.e., microprocessor-based, controller-assisted) vehicular compound mechanical transmission system 10, particularly well 25 suited to utilize the adaptive neutral sensing control system/method of the present invention, may be seen by reference to Figs. 1-5B. System 10 is of the type commonly utilized in heavy-duty vehicles, such as the tractors of tractor/semi-trailer vehicles, and includes an engine, typically a diesel engine 12, a master friction clutch 14 contained within a 30 clutch housing, a multiple-speed compound transmission 16, and a drive axle assembly (not shown). The transmission 16 includes an output 5 98-TRN-092 shaft 20 drivingly coupled to a vehicle drive shaft 22 by a universal joint 24 for driving the drive axle assembly. The transmission 16 is housed within a transmission housing to which is directly mounted the shift tower of the shift lever assembly 30. The present system is equally applicable to 5 remotely mounted shift levers, as are used in cab-over-engine types of vehicles. Fig. 2 illustrates an H-type shift pattern for assisted manual shifting of a combined range-and-splitter-type compound transmission shifted by a manually operated shift lever. Briefly, the shift lever 31 is movable in the 10 side-to-side or X-X direction to select a particular ratio or ratios to be engaged and is movable in the fore and aft or Y-Y direction to selectively engage and disengage the various ratios. The shift pattern (usually referred to as an "H-type" shift pattern) includes an automatic range shifting feature and may include automatically selected and/or implemented splitter shifting, 15 as is known in the prior art. Manual transmissions utilizing shift mechanisms and shift patterns of this type are well known in the prior art and may be appreciated in greater detail by reference to aforementioned U.S. Pats. No. 5,000,060 and 5,390,561. Typically, the shift lever assembly 30 will include a shift finger or the 20 like (not shown) extending downwardly into a shifting mechanism 32, such as a multiple-rail shift bar housing assembly or a single shift shaft assembly, as is well known in the prior art and as is illustrated in aforementioned U.S. Pats. No. 4,455,883; 4,550,627; 4,920,815 and 5,272,931. In the automatic range shifting,J!eaturex as the shift lever moves in the 25 transition area or band between the middle leg (3/4-5/6) and the righthand Teg (7/8-9/10) of the shift pattern, it will cross a point, AR, which will actuate a sensor, such as a magnetic, mechanical or electrical range switch, or will be sensed by a position sensor, to cause initiation of automatic implementation of a range shift. 30 As is well known, the shift lever 31 is moved in the horizontal (X-X) direction to select a desired leg (R/1-2, 3-4/5-6 or 7-8/9-10) of the shift 6 38-TRN-092 pattern and in the vertical (Y-Y) direction to engage and disengage particular ratios. The bight or transition portion 200 of thei shift pattern connects the legs and represents a vertically centered (vertically non-displaced) or neutral positoin in the shift pattern. As will be discussed in detail below, the 5 magnitude of vertical displacement from the vertically centered or bight portion is an indication that main section 16A is in an engaged or a neutral condition. As used herein, the terms "vertical" and "horizontal" refer to directions in Fig. 2, are used for illustrative purposes, and are not intended to be limiting. 10 Shifting of transmission 16, comprising main section 16A coupled in series to auxiliary section 16B, is semi-automaticaliy implemented/assisted by the vehicular transmission system 10, illustrated in Figs. 1-5B. Main section 16A includes an input shaft 26, which is operatively coupled to the drive or crank shaft 28 of the vehicle engine 12 by master clutch 14, and 15 output shaft 20 of auxiliary section 16B is operatively coupled, commonly by means of a drive shaft 24, to the drive wheels of the vehicle. The auxiliary section 16B is a splitter type, preferably a combined range-and-splitter type, as illustrated in U.S. Pats. No. 4,754,665 and 5,390,561. The change-gear ratios available from main transmission section 16 20 are manually selectable by manually positioning the shift lever 31 according to the shift pattern prescribed to engage the particular desired change gear ratio of main section 16A. The system may include sensors 30 (for sensing engine rotational speed (ES)), 32 (for sensing input shaft rotational speed (IS)), and 34 (for 25 sensing output shaft rotational speed (OS)), and providing signals indicative thereof. As is known, with the clutch 14 (i.e., no slip) engaged and the transmission engaged in a known gear ratio, ES = IS = OSGR (see U.S. Pat. No. 4,361,060). Accordingly, if clutch 14 is engaged, engine speed and input shaft speed may be considered as equal. Input shaft speed sensor 32 30 may be eliminated and engine speed (ES), as sensed by a sensor or over a data link (DL), substituted therefor. 7 98-TRN-092 Engine 12 is electronically controlled, including an electronic controller 36 communicating over an electronic data link (DL) operating under an industry standard protocol such as SAE J-1922, SAE J-1939, ISO 11898 or the like. Throttle position (operator demand) is a desirable 5 parameter for selecting shifting points and in other control logic. A separate throttle position sensor 38 may be provided or throttle position (THL) may be sensed from the data link. Gross engine torque (TEG) and base engine friction torque (TBEF) also are available on the data link. A manual clutch pedal 40 controls the master clutch 14, and a 10 sensor 42 provides a signal (CL) indicative of clutch-engaged or -disengaged condition. The condition of the clutch also may be determined by comparing engine speed to input shaft speed if both signals are available. An auxiliary section actuator 44 including a range shift actuator and a splitter actuator 46 is provided for operating the range clutch and the 15 splitter section clutch in accordance with command output signals from ECU 48. The shift lever 31 has a knob 50 which contains splitter selector switch 52 by which a driver's intent to initiate a splitter shift may be sensed. System 10 may include a driver's display unit 54 including a graphic 20 representation of the six-position shift pattern with individually lightable display elements 56, 58, 60, 62, 64 and 66, representing each of the selectable engagement positions. Preferably, each half of the shift pattern display elements {i.e., 58A and 58B) will be individually lightable, allowing the display to inform the driver of the lever and splitter position for the 25 engaged ratio. The system includes a control unit or ECU 48, preferably a microprocessor-based control unit of the type illustrated in U.S. Pats. No. 4,595,986; 4,361,065 and 5,335,566, the disclosures of which are incorporated herein by reference, for receiving input signals 68 and 30 processing same according to predetermined logic rules to issue command output signals 70 to system actuators, such as the splitter section 8 98-TRN-092 actuator 46, the engine controller 36, the range shift actuator and/or the display unit 54. A separate system controller may be utilized, or the engine controller ECU 36 communicating over an electronic data link may be utilized. 5 As shown in U.S. Pat. No. 5,651,292 (the disclosure of which is incorporated herein by reference) and co-pending patent application U.S. Serial No. 08/597,304 (assigned to the assignee of this application), the splitter actuator 46 is, preferably, a three-position device, allowing a selectable and maintainable splitter section neutral. Alternatively, a 10 "pseudo" splitter-neutral may be provided by deenergizing the splitter actuator when the splitter clutch is in an intermediate, non-engaged position. The structure of the 10-forward-speed combined range-and-splitter-type transmission 16 is schematically illustrated in Fig. 3. Transmissions of 15 this general type are disclosed in aforementioned U.S. Pats. No. 5,000,060; 5,370,013 and 5,390.561. Transmission 16 includes a main section 16A and an auxiliary section 16B, both contained within a housing including a forward end wall 16C, which may be defined by the clutch housing, and a rearward end 20 wall 16D, but (in this particular embodiment) not an intermediate wall. Input shaft 26 carries input gear 76 fixed for rotation therewith and defines a rearwardly opening pocket wherein a reduced diameter extension of output shaft 20 is piloted. A non-friction bushing or the like may be provided in the pocket or blind bore. The rearward end of input shaft 26 is 25 supported by bearing 78 in front end wall 16C, while the rearward end of output shaft 20 is supported by bearing assembly 80 in rear end wall 16D. The mainshaft 82, which carries mainshaft clutches 84 and 86, and the mainshaft splitter clutch 88 is in the form of a generally tubular body having an externally splined outer surface and an axially extending through 30 bore for passage of output shaft 20. Shift forks 90 and 92 are provided for shifting clutches 84 and 86, respectively (see Fig. 5A). Mainshaft 82 is 9 98-TRN-092 independently rotatable relative to input shaft 26 and output shaft 20 and preferably is free for limited radial movement relative thereto. The main section 16A includes two substantially identical main section countershaft assemblies 94, each comprising a main section 5 countershaft 96 carrying countershaft gears 98, 100, 102, 104 and 106 fixed thereto. Gear pairs 98, 100, 102, 104 and 106 are constantly meshed with input gear 76, mainshaft gears 108 and 110 and an idler gear (not shown), which is meshed with reverse mainshaft gear 112, respectively. 10 Main section countershaft 96 extends rearwardly into the auxiliary section, where its rearward end is supported directly or indirectly in rear housing end wall 16D. The auxiliary section 16B of transmission 16 includes two substantially identical auxiliary countershaft assemblies 114, each including 15 an auxiliary countershaft 116 carrying auxiliary countershaft gears 118, 120 and 122 for rotation therewith. Auxiliary countershaft gear pairs 118, 120 and 122 are constantly meshed with splitter gear 124, splitter/range gear 126 and range gear 128, respectively. Splitter clutch 88 is fixed to mainshaft 82 for selectively clutching either gear 124 or 126 thereto, while 20 synchronized range clutch 130 is fixed to output shaft 20 for selectively clutching either gear 126 or gear 128 thereto. Auxiliary countershafts 116 are generally tubular in shape, defining a through bore for receipt of the rearward extensions of the main section countershafts 96. Bearings or bushings are provided to rotatably support 25 auxiliary countershaft 116 on main section countershaft 96. The splitter jaw clutch 88 is a double-sided, non-synchronized clutch assembly which may be selectively positioned in the rightwardmost or leftwardmost positions for engaging either gear 126 or gear 124, respectively, to the mainshaft 82 or to an intermediate position wherein 30 neither gear 124 or 126 is clutched to the main shaft. Splitter jaw clutch 88 is axially positioned by means of a shift fork 98 controlled by a 10 98-TRN-092 three-position actuator, such as a piston actuator, which is responsive to a driver selection switch such as a button or the like on the shift knob, as is known in the prior art and to control signals from ECU 48 (see U.S. Pat. No. 5,661,998). Two-position synchronized range clutch assembly 130 is 5 a two-position clutch which may be selectively positioned in either the rightwardmost or leftwardmost positions thereof for selectively clutching either gear 128 or 126, respectively, to output shaft 20. Clutch assembly 130 is positioned by means of a shift fork (not shown) operated by means of a two-position piston device. Either piston actuator may be 10 replaced by a functionally equivalent actuator, such as a ball screw mechanism, ball ramp mechanism or the like. By selectively axially positioning both the splitter clutch 88 and the range clutch 130 in the forward and rearward axial positions thereof, four distinct ratios of mainshaft rotation to output shaft rotation may be 15 provided. Accordingly, auxiliary transmission section 16B is a three-layer auxiliary section of the combined range and splitter type providing four selectable speeds or drive ratios between the input (mainshaft 82) and output (output shaft 20) thereof. The main section 16A provides a reverse and three potentially selectable forward speeds. However, one of the 20 selectable main section forward gear ratios, the low-speed gear ratios associated with mainshaft gear 110, is not utilized in the high range. Thus, transmission 16 is properly designated as a "(2 +1)x(2x2)" type transmission providing nine or ten selectable forward speeds, depending upon the desirability and practicality of splitting the low gear ratio. 25 Splitter shifting of transmission 16 is accomplished responsive to initiation by a vehicle operator-actuated splitter button 52 or the like, usually a button located at the shift lever knob, while operation of the range clutch shifting assembly is an automatic response to movement of the gear shift lever between the central and rightwardmost legs of the shift pattern and 30 across the actuation point AR, as illustrated in Fig. 2. Alternatively, splitter shifting may be automated (see U.S. Pat. No. 5,435,212). Range shift 11 98-TRN-092 devices of this general type are known in the prior art and may be seen by reference to aforementioned U.S. Pats. No. 3,429,202; 4,455,883; 4,561,325 and 4,663,725. Although the present invention is illustrated in the embodiment of a 5 compound transmission not having an intermediate wall, the present invention is equally applicable to transmissions of the type illustrated in aforementioned U.S. Pats. No. 4,754,665; 5,193,410 and 5,368,145. In the prior art, especially for manual transmissions, the splitter clutches were operated by two-position actuators and, thus, were provided 10 with a relatively small backlash {i.e., about .008-.012 inches backlash for a clutch having about a 3.6-inch pitch diameter) to prevent unduly harsh splitter shifting. Typically, with the above backlash and the usual engagement forces, at greater than about 60 RPM input shaft synchronous error, the clutch teeth would ratchet or "buzz" and clutch engagement 15 would not occur. As is known (see U.S. Pat. No. 5,052,535, the disclosure of which is incorporated herein by reference), allowable relative rotational speed at which the positive clutches will properly engaged (i.e., sufficient clutch tooth penetration will occur) is a directly proportional function of the total 20 effective backlash in the clutch system. The maximum allowable asynchronous conditions at which clutch engagement is allowed is selected in view of the most harsh clutch engagement which is acceptable. In change-gear transmissions utilizing the non-synchronized positive clutch structures, especially for heavy-duty vehicles, for a given total 25 backlash (i.e., a given maximum allowably harsh clutch engagement), the range of asynchronous conditions at which the clutch members will engage is often narrower than desirable under certain conditions, making shifting more difficult. According to the present invention, and as more fully described in 30 aforementioned U.S. Pat. No. 5,651,292, the interengaging clutch teeth provided on splitter clutch 88 and on splitter gear 124 and splitter/range 12 98-TRN-092 gear 126 are of a relatively large backlash (i.e., about .020-.060 inches for a 3.6-inch pitch diameter clutch), which will assure that almost any attempted splitter shift under full force will be completed. The clutch 88 is moved by a shift fork 98 attached to the piston 5 rod 140 of the piston actuator assembly 142 (see Fig. 4). Actuator assembly 142 may be a conventional three-position actuator (see U.S. Pat. No. 5,054,591, the disclosure of which is incorporated herein by reference) or an actuator of the type illustrated in U.S. Pat. No. 5,682,790 or 5,661,998 (the disclosures of which are incorporated herein by reference), 10 wherein pulse width modulation of a selectively pressurized and exhausted chamber 144 may be used to achieve the three splitter positions (L, N, H) of the shift fork. Preferably, the splitter clutch actuator 142 will, be capable of applying a variable force, such as by pulse width modulation, of supply pressure. A 15 force lesser than full force may be utilized when disengaging and/or when synchronous conditions cannot be verified. The controller 48 is provided with logic rules under which, if the main section is engaged, a shift from splitter neutral into a selected target splitter ratio is initiated such that, under normal conditions, including proper 20 operator fuel control, the synchronous error (which is equal to input shaft rotational speed minus the product of output shaft rotational speed and transmission target gear ratio) is expected to be equal to or less than a value selected to give smooth, high-quality shifts ((IS - (0SGR)) = ERROR 25 acceleration/deceleration and actuator reaction times. In certain situations, the logic rules will recognize operating conditions wherein the preferred synchronous window (i.e., IS = (OS*GR) ± 60 RPM) must be expanded to accomplish a splitter shift, even at the expense of shift quality. These situations, usually associated with upshifts, 30 include if shifting attempted at low engine speeds wherein expected engine speed at shift completion will be undesirably low, if deceleration of the 13 98-TRN-092 output shaft is relatively high (dOS/dt engine is relatively low (dES/dt > REF) and/or if the absolute value of the synchronous error is not approaching the normal value at an acceptable rate. In the preferred embodiment, if main section neutral is sensed, the 5 splitter will be caused to engage under full force, regardless of the presence or absence of synchronous conditions. The position of the shift lever 31 or of the shifting mechanism 32 controlled thereby may be sensed by a position sensor device. Various positioning sensing assemblies are known in the prior art, with a preferred 10 type illustrated in allowed U.S. Serial No. 08/695,052, assigned to the assignee of this application, the disclosure of which is incorporated herein by reference. Referring to Figs. 5A and 5B, shifting mechanism 32 is illustrated as a single shift shaft device 160 having a shaft 162 which is rotatable in 15 response to X-X movements of shift lever 31 and axially movable in response to Y-Y movements of shift lever 31. Mechanisms of this type are described in detail in aforementioned U.S. Pat. No. 4,920,815. Shift shaft 162 carries the main section shift forks 90 and 92 for selective axial movement therewith and a shift block member 164 for 20 receiving a shift finger or the like. A pair of coils 166 and 168 provide a pair of signals (collectively GR) indicative of the axial and rotational position of shaft 162 and, thus, of shift lever 31 relative to the shift pattern illustrated in Fig. 2. Preferably, the rate of change of position (dGR/dt) also may be determined and utilized to enhance shifting of the system 10. 25 By way of example, referring to Fig. 2, if shift lever position can be sensed, the need for a fixed switch or the like at point AR to sense a required initiation of a shift between low range and high range is eliminated. Further, as physical switches are no longer required, the shift pattern position at which a range shift will be commanded, AR, can be varied, such 30 as to points 180, 182 or 184, to enhance system performance under various operating conditions. 14 If In first (1st) through fourth (4th), a shift Into high range is very unlikely and the auto range shift initiation point may be moved to position 184 (away from the expected shift lever path) to prevent inadvertent actuation of a range shift, if in sixth (6th) with a high engine speed, a shift Into high range is likely and moving the auto range initiation point to position 180 wilt allow for a quicker initiation of a range shift. Similarly, if in fifth (5th), an intentional shift into high range is only moderately likely, and the range shift initiation point may be moved to position 182. According to the present invention, the operator is allowed to control engine fueling unless the current vehicle operating conditions indicate that his/her operation of the throttle pedal will not allow the Jaw clutches associated with the current target ratio to engage. If operating conditions, including operator setting of the throttle pedal, indicate that the operator will complete a splitter shift into target ratio, the engine will be fueled in accordance with operator throttle setting, if not, automatic engine fueling may occur, if the splitter section does engage prior to the main section (as is preferred), the operator will remain in complete control of engine fueling to complete the shift by engaging the main section. The state of engagement (i.e., engaged or neutral) of the main transmission section 16A is an important control parameter for system 10. Byway of example, if main section neutral is sensed, the splitter may be commanded to a full force engagement, regardless of the existence or absence of synchronous conditions. Also, if the main section is engaged while the splitter Is in neutral, the system wiSI not cause splitter engagement until substantial synchronous is sensed and may then initiate automatic fuel control if required. Of course, it is important to prevent or minimize false determinations of main section neutral and/or engaged conditions. Referring to Fig.2, a first narrow band 202 and a second wider band 204 defined respectively by a first maximum value and a second maximum value of vertical displacements from the bight portion 200 are utilized are utilized to determine if the main section is or is not in neutral. The second maximum value is greater than the first maximum value, if the transmission ... 15 98-TRN-092 main section is not confirmed as being in main section neutral, the neutral confirmation band will be the narrower band 202. This will assure that the main section 16A is truly in neutral before declaring a main section neutral condition. If the transmission main section 16A is confirmed as being in 5 neutral, the neutral confirmation band will be the wider band 204. This assures that mere overshooting of neutral or raking of main section jaw clutches will not be incorrectly interpreted as a main section engaged condition. Sensing the shift lever at point 206 will always be interpreted as main 10 section neutral, and sensing the shift lever at point 208 will always be interpreted as main section engaged. However, if the shift lever is sensed at point 210, this will not cause a previous determination of a neutral or engaged condition to change. Vehicle operating conditions other than or in addition to currently 1 5 engaged or neutral condition of the main section 16A may be used to vary the width of the neutral sensing bands. Accordingly, it may be seen that a new and improved computer-assisted, manually shifted transmission system is provided, which provides enhanced shift lever position-based sensing of transmission neutral. 20 Although the present invention has been described with a certain degree of particularity, it is understood that the description of the preferred embodiment is by way of example only and that numerous changes to form and detail are possible without departing from the spirit and scope of the invention as hereinafter claimed. 16 We Claim: 1, A method for controlling assisted shifting in a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising: sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from said vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than 17 said first maxim urn value, if said main transmission section was last determined to be in neutral; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section. 2. The method as claimed in claim 1 wherein said transmission is a compound transmission having a splitter section (16B) connected in series with said main transmission section. 3. The method as claimed in claim 1 wherein said transmission is driven by a fuel-controlled engine (12) and said input signals include signals indicative of engine rotational speed and vehicle ground speed. 4. The method as claimed in claim 2 wherein said transmission also includes a range section (16B) connected in series with said main transmission section and said shift pattern comprises at least one first leg (3/4-5/6) for selection of low range ratios, a second leg (7/8-9/10), parallel and adjacent to a first leg, for selection of high range ratios, and a transition segment (200), extending perpendicularly between said first and second legs, said transition segment defining the vertically non-displaced position in said shift pattern. 5. A control system for performing the method as claimed in claim 1, comprising a transmission (16) having amain transmission section (16A), a manually operated shift lever for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertically centered n on-displaced position (200) are indicative of said main 18 transmission section being in neutral and greater vertical displacements from said vertically centered position are indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said control system comprising: means for sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; means for comparing said current shift lever vertical position to a variable band of vertical displacements from said vertically non-displaced position to determine if said main transmission section is currently engaged or is in neutral: means for causing said band of vertical displacement from said vertically displaced position to have a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said first maximum value, if said main transmission section was last determined to be in neutral; and means for controlling said transmission system as a function of the current determined engaged and neutral conditions of said main transmission section. 19 6", The control system as claimed in claim 5 wherein said transmission is a compound transmission having a splitter section (10B) connected in series with said main transmission section. 7. The control system as claimed in claim 5 wherein said transmission is driven by a fuel-controlled engine (12) and said input signals include signals indicative of engine rotational speed and vehicle ground speed. S. The control system as claimed in claim 6 wherein said transmission also includes a range section (16B) connected in series with said main transmission section and said shift pattern comprises at least one first leg (3/4-5/6) for selection of low range ratios, a second leg (7/8-9/10), parallel and adjacent to a first leg, for selection of high range ratios, and a transition segment (200), extending perpendicularly between said first and second legs, said transition segment defining the vertically non-displaced position in said shift pattern. 9. A method for controlling assisted shifting in a vehicular transmission system as claimed in claim 1 comprising a transmission having a main transmission section, a manually operated shift lever for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertically centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are indicative of said main transmission section being engaged in a gear ratio, a sensor for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a 20 system controller for receiving input signals including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals to system actuators, said method comprising: sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged or is in neutral, said band of vertical displacement from said vertically displaced position having a first maximum value (202) if a first set of vehicle operating conditions was last determined to exist and a second maximum value (204), greater than said first maximum value, if a second set of vehicle operating conditions was last determined to exist; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section. A method for controlling assisted shifting tn a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are Indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising: sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from sald vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said First maximum value, if said main transmission section was last determined to be in neutral; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section. A method for controlling assisted shifting tn a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are Indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising: sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from sald vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said First maximum value, if said main transmission section was last determined to be in neutral; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section.

Full Text

- 1A - 98-TRN-092
ADAPTIVE NEUTRAL SENSING
BACKGROUND OF THE INVENTION RELATED APPLICATIONS
This application is related to the following co-pending applications, all assigned to EATON CORPORATION, the assignee of this application:
5 Serial No. 08/ [96-TRN-263] mailed 04/01/98 and titled
RANGE SHIFT CONTROL
Serial No. 08/ [97-TRN-561] mailed 04/01/98 and titled
ADAPTIVE UPSHIFT JAW CLUTCH ENGAGEMENT CONTROL
Serial No. 08/ [97-TRN-566] mailed 04/01/98 and titled
10 ENGINE FUEL CONTROL FOR COMPLETING SHIFTS IN CONTROLLER-
ASSISTED, MANUALLY SHIFTED TRANSMISSIONS
Serial No. 08/ [97-TRN-567] mailed 04/01/98 and titled
DYNAMIC RANGE SHIFT ACTUATION
Serial No. 08/ [98-TRN-067] mailed 04/01/98 and titled JAW
15 CLUTCH ENGAGEMENT CONTROL FOR ASSISTED, MANUALLY
SHIFTED, SPLITTER-TYPE TRANSMISSION SYSTEM
Serial No. 08/ [98-TRN-101] mailed 04/01/98 and titled
ADAPTIVE SPLITTER ACTUATOR ENGAGEMENT FORCE CONTROL
Serial No. 08/902,603 filed 08/07/97 and titled PARIALLY
20 AUTOMATED, LEVER-SHIFTED MECHANICAL TRANSMISSION
SYSTEM
Serial No. 08/ [97-rTRN-495] mailed 12/11/97 and titled
ASSISTED LEVER-SHIFTED TRANSMISSION.
25 FIELD OF THE INVENTION
The present invention relates to a control system/method for controlling automatically implemented and/or assisted shifting. In particular, the present invention relates to automatically implemented and/or assisted shifting in a transmission (such as a compound transmission having a main
30 section shifted by a manually opera ted shift lever or shift selector) as a

2 98 TRN-092
function of the sensed presence or absence of a main section neutral condition. More particularly, the present invention relates to controls for such shifting which determine if the main transmission section is in neutral or is engaged in response to sensed shift lever position and which will vary the shift lever positions at which a main section neutral condition is declared in response to sensed vehicle operating conditions.
DESCRIPTION OF THE PRIOR ART
Compound manually shifted mechanical transmissions of the range, splitter and/or combined range/splitter type are in wide use in heavy-duty vehicles and are well known in the prior art, as may be seen by reference to U.S. Pats. No. 4,754,665; 5,272,929; 5,370,013 and 5.390,561, 5,546,823; 5,609.062 and 5,642,643, the disclosures of which are incorporated herein by reference. Typically, such transmissions include a
.IT
main section shifted directly or remotely by a manual shift lever and one or more auxiliary sections connected in series therewith. The auxiliary sections most often were shifted by a slave actuator, usually pneumatically, hydraulically, mechanically and/or electrically operated, in response to manual operation of one or more master switches. Shift controls for such systems by be seen by reference to U.S. Pats. No. 4,455,883; 4,550,627; 4,899,607; 4,920,815; 4,974,468; 5,000,060; 5,272,931; 5,281,902; 5,222,404 and 5,350,561, the disclosures of which are incorpbraTecrrTerein by reference.
Fully or partially automated transmission systems wherein a microprocessor-based electronic control unit (ECU) receives input signals indicative of various system operating conditions and processes same according to logic rules to issue command output signals to one or more system actuators are known in the prior art, as may be seen by reference to U.S. Pats. No. 4,361,060; 4,593,580; 4,595,986; 4,850,236; 5,435,212; 5,582,069; 5,582,558; 5,620,392; 5,651,292 and 5,679,096; 5,682,790; the disclosures of which are incorporated herein by reference.

3 98-TRN-092
These systems often used the sensed engaged or neutral condition of the transmission and/or transmission main section as an important control parameter.
5 SUMMARY OF THE INVENTION
A preferred embodiment of the present invention involves a computer-assisted mechanical compound transmission system wherein the main section is shifted by a manually controlled shift lever operating in a predetermined shift pattern and the engine is fueled and/or the auxiliary
10 sections are shifted by actuators at least partially controlled by an ECU to
enhance shifting. The ECU uses sensed and/or calculated inputs indicative of system operating parameters, such as operation of a splitter switch, position and/or rate of change of position of the shift lever, engaged gear ratio, engine speed, output shaft speed, clutch condition and/or throttle
15 pedal position, to assist shifting by controlling engine fueling and/or
operation of the range and/or splitter shift actuators.
In accordance with the present invention, the drawbacks of the prior art are minimized or overcome by the provision of a computer-enhanced, lever-shifted compound vehicular transmission system having a position
20 sensor for sensing shift lever position and control logic to determine main
section condition as a variable function of such sensed position and logic for sensing/determining vehicle operating conditions and varying the shift lever positions at which main section neutral is declared as a function of vehicle operating conditions to enhance system performance.
25 Accordingly, it is an object of the present invention to provide ECU
assistance for enhanced shifting of a mechanical compound transmission having a main section shifted by a manually operated shift lever.
Another object of the present invention is to provide an improved computer-assisted transmission system, preferably including a compound
30 transmission, having a lever position sensor for determining a main section
neutral condition and having logic for adaptively modifying the lever

4 98-TRN-092
positions considered to be an indication of transmission main section neutral as a function of sensed vehicle operating conditions.
These and other objects and advantages of the present invention will
become apparent from a reading of the following description of the
5 preferred embodiment taken in connection with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a schematic illustration of an ECU-assisted compound
mechanical transmission system advantageously utilizing the range shifting
10 control of the present invention.
Fig. 2 is a chart illustrating the shift pattern and representative numerical ratios for the transmission of Fig. 1.
Fig. 3 is a schematic illustration of the structure of the compound mechanical transmission of Fig. 1.
15 Fig. 4 is a schematic illustration of a three-position splitter actuator
for use with the transmission system of Fig. 1.
Figs. 5A and 5B are schematic illustrations of a shift shaft position sensor mechanism for use in the system of Fig. 1.
Fig. 6 is a schematic illustration, in flow chart format, of the control
20 of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A computer-assisted (i.e., microprocessor-based, controller-assisted)
vehicular compound mechanical transmission system 10, particularly well
25 suited to utilize the adaptive neutral sensing control system/method of the
present invention, may be seen by reference to Figs. 1-5B.
System 10 is of the type commonly utilized in heavy-duty vehicles,
such as the tractors of tractor/semi-trailer vehicles, and includes an engine,
typically a diesel engine 12, a master friction clutch 14 contained within a
30 clutch housing, a multiple-speed compound transmission 16, and a drive
axle assembly (not shown). The transmission 16 includes an output

5 98-TRN-092
shaft 20 drivingly coupled to a vehicle drive shaft 22 by a universal joint 24
for driving the drive axle assembly. The transmission 16 is housed within a
transmission housing to which is directly mounted the shift tower of the
shift lever assembly 30. The present system is equally applicable to
5 remotely mounted shift levers, as are used in cab-over-engine types of
vehicles.
Fig. 2 illustrates an H-type shift pattern for assisted manual shifting of a combined range-and-splitter-type compound transmission shifted by a manually operated shift lever. Briefly, the shift lever 31 is movable in the
10 side-to-side or X-X direction to select a particular ratio or ratios to be
engaged and is movable in the fore and aft or Y-Y direction to selectively engage and disengage the various ratios. The shift pattern (usually referred to as an "H-type" shift pattern) includes an automatic range shifting feature and may include automatically selected and/or implemented splitter shifting,
15 as is known in the prior art. Manual transmissions utilizing shift
mechanisms and shift patterns of this type are well known in the prior art and may be appreciated in greater detail by reference to aforementioned U.S. Pats. No. 5,000,060 and 5,390,561.
Typically, the shift lever assembly 30 will include a shift finger or the
20 like (not shown) extending downwardly into a shifting mechanism 32, such
as a multiple-rail shift bar housing assembly or a single shift shaft assembly, as is well known in the prior art and as is illustrated in aforementioned U.S. Pats. No. 4,455,883; 4,550,627; 4,920,815 and 5,272,931.
In the automatic range shifting,J!eaturex as the shift lever moves in the
25 transition area or band between the middle leg (3/4-5/6) and the righthand
Teg (7/8-9/10) of the shift pattern, it will cross a point, AR, which will actuate a sensor, such as a magnetic, mechanical or electrical range switch, or will be sensed by a position sensor, to cause initiation of automatic implementation of a range shift.
30 As is well known, the shift lever 31 is moved in the horizontal (X-X)
direction to select a desired leg (R/1-2, 3-4/5-6 or 7-8/9-10) of the shift

6 38-TRN-092
pattern and in the vertical (Y-Y) direction to engage and disengage particular
ratios. The bight or transition portion 200 of thei shift pattern connects the
legs and represents a vertically centered (vertically non-displaced) or neutral
positoin in the shift pattern. As will be discussed in detail below, the
5 magnitude of vertical displacement from the vertically centered or bight
portion is an indication that main section 16A is in an engaged or a neutral condition. As used herein, the terms "vertical" and "horizontal" refer to directions in Fig. 2, are used for illustrative purposes, and are not intended to be limiting.
10 Shifting of transmission 16, comprising main section 16A coupled in
series to auxiliary section 16B, is semi-automaticaliy implemented/assisted by the vehicular transmission system 10, illustrated in Figs. 1-5B. Main section 16A includes an input shaft 26, which is operatively coupled to the drive or crank shaft 28 of the vehicle engine 12 by master clutch 14, and
15 output shaft 20 of auxiliary section 16B is operatively coupled, commonly
by means of a drive shaft 24, to the drive wheels of the vehicle. The auxiliary section 16B is a splitter type, preferably a combined range-and-splitter type, as illustrated in U.S. Pats. No. 4,754,665 and 5,390,561.
The change-gear ratios available from main transmission section 16
20 are manually selectable by manually positioning the shift lever 31 according
to the shift pattern prescribed to engage the particular desired change gear ratio of main section 16A.
The system may include sensors 30 (for sensing engine rotational speed (ES)), 32 (for sensing input shaft rotational speed (IS)), and 34 (for
25 sensing output shaft rotational speed (OS)), and providing signals indicative
thereof. As is known, with the clutch 14 (i.e., no slip) engaged and the transmission engaged in a known gear ratio, ES = IS = OS*GR (see U.S. Pat. No. 4,361,060). Accordingly, if clutch 14 is engaged, engine speed and input shaft speed may be considered as equal. Input shaft speed sensor 32
30 may be eliminated and engine speed (ES), as sensed by a sensor or over a
data link (DL), substituted therefor.

7 98-TRN-092
Engine 12 is electronically controlled, including an electronic
controller 36 communicating over an electronic data link (DL) operating
under an industry standard protocol such as SAE J-1922, SAE J-1939,
ISO 11898 or the like. Throttle position (operator demand) is a desirable
5 parameter for selecting shifting points and in other control logic. A separate
throttle position sensor 38 may be provided or throttle position (THL) may be sensed from the data link. Gross engine torque (TEG) and base engine friction torque (TBEF) also are available on the data link.
A manual clutch pedal 40 controls the master clutch 14, and a
10 sensor 42 provides a signal (CL) indicative of clutch-engaged or -disengaged
condition. The condition of the clutch also may be determined by comparing engine speed to input shaft speed if both signals are available. An auxiliary section actuator 44 including a range shift actuator and a splitter actuator 46 is provided for operating the range clutch and the
15 splitter section clutch in accordance with command output signals from
ECU 48. The shift lever 31 has a knob 50 which contains splitter selector switch 52 by which a driver's intent to initiate a splitter shift may be sensed.
System 10 may include a driver's display unit 54 including a graphic
20 representation of the six-position shift pattern with individually lightable
display elements 56, 58, 60, 62, 64 and 66, representing each of the selectable engagement positions. Preferably, each half of the shift pattern display elements {i.e., 58A and 58B) will be individually lightable, allowing the display to inform the driver of the lever and splitter position for the
25 engaged ratio.
The system includes a control unit or ECU 48, preferably a microprocessor-based control unit of the type illustrated in U.S. Pats. No. 4,595,986; 4,361,065 and 5,335,566, the disclosures of which are incorporated herein by reference, for receiving input signals 68 and
30 processing same according to predetermined logic rules to issue command
output signals 70 to system actuators, such as the splitter section

8 98-TRN-092
actuator 46, the engine controller 36, the range shift actuator and/or the display unit 54. A separate system controller may be utilized, or the engine controller ECU 36 communicating over an electronic data link may be utilized.
5 As shown in U.S. Pat. No. 5,651,292 (the disclosure of which is
incorporated herein by reference) and co-pending patent application U.S. Serial No. 08/597,304 (assigned to the assignee of this application), the splitter actuator 46 is, preferably, a three-position device, allowing a selectable and maintainable splitter section neutral. Alternatively, a
10 "pseudo" splitter-neutral may be provided by deenergizing the splitter
actuator when the splitter clutch is in an intermediate, non-engaged position.
The structure of the 10-forward-speed combined range-and-splitter-type transmission 16 is schematically illustrated in Fig. 3. Transmissions of
15 this general type are disclosed in aforementioned U.S. Pats. No. 5,000,060;
5,370,013 and 5,390.561.
Transmission 16 includes a main section 16A and an auxiliary section 16B, both contained within a housing including a forward end wall 16C, which may be defined by the clutch housing, and a rearward end
20 wall 16D, but (in this particular embodiment) not an intermediate wall.
Input shaft 26 carries input gear 76 fixed for rotation therewith and defines a rearwardly opening pocket wherein a reduced diameter extension of output shaft 20 is piloted. A non-friction bushing or the like may be provided in the pocket or blind bore. The rearward end of input shaft 26 is
25 supported by bearing 78 in front end wall 16C, while the rearward end of
output shaft 20 is supported by bearing assembly 80 in rear end wall 16D.
The mainshaft 82, which carries mainshaft clutches 84 and 86, and
the mainshaft splitter clutch 88 is in the form of a generally tubular body
having an externally splined outer surface and an axially extending through
30 bore for passage of output shaft 20. Shift forks 90 and 92 are provided for
shifting clutches 84 and 86, respectively (see Fig. 5A). Mainshaft 82 is

9 98-TRN-092
independently rotatable relative to input shaft 26 and output shaft 20 and preferably is free for limited radial movement relative thereto.
The main section 16A includes two substantially identical main
section countershaft assemblies 94, each comprising a main section
5 countershaft 96 carrying countershaft gears 98, 100, 102, 104 and 106
fixed thereto. Gear pairs 98, 100, 102, 104 and 106 are constantly meshed with input gear 76, mainshaft gears 108 and 110 and an idler gear (not shown), which is meshed with reverse mainshaft gear 112, respectively.
10 Main section countershaft 96 extends rearwardly into the auxiliary
section, where its rearward end is supported directly or indirectly in rear housing end wall 16D.
The auxiliary section 16B of transmission 16 includes two substantially identical auxiliary countershaft assemblies 114, each including
15 an auxiliary countershaft 116 carrying auxiliary countershaft gears 118, 120
and 122 for rotation therewith. Auxiliary countershaft gear pairs 118, 120 and 122 are constantly meshed with splitter gear 124, splitter/range gear 126 and range gear 128, respectively. Splitter clutch 88 is fixed to mainshaft 82 for selectively clutching either gear 124 or 126 thereto, while
20 synchronized range clutch 130 is fixed to output shaft 20 for selectively
clutching either gear 126 or gear 128 thereto.
Auxiliary countershafts 116 are generally tubular in shape, defining a through bore for receipt of the rearward extensions of the main section countershafts 96. Bearings or bushings are provided to rotatably support
25 auxiliary countershaft 116 on main section countershaft 96.
The splitter jaw clutch 88 is a double-sided, non-synchronized clutch assembly which may be selectively positioned in the rightwardmost or leftwardmost positions for engaging either gear 126 or gear 124, respectively, to the mainshaft 82 or to an intermediate position wherein
30 neither gear 124 or 126 is clutched to the main shaft. Splitter jaw
clutch 88 is axially positioned by means of a shift fork 98 controlled by a

10 98-TRN-092
three-position actuator, such as a piston actuator, which is responsive to a
driver selection switch such as a button or the like on the shift knob, as is
known in the prior art and to control signals from ECU 48 (see U.S. Pat.
No. 5,661,998). Two-position synchronized range clutch assembly 130 is
5 a two-position clutch which may be selectively positioned in either the
rightwardmost or leftwardmost positions thereof for selectively clutching either gear 128 or 126, respectively, to output shaft 20. Clutch assembly 130 is positioned by means of a shift fork (not shown) operated by means of a two-position piston device. Either piston actuator may be
10 replaced by a functionally equivalent actuator, such as a ball screw
mechanism, ball ramp mechanism or the like.
By selectively axially positioning both the splitter clutch 88 and the range clutch 130 in the forward and rearward axial positions thereof, four distinct ratios of mainshaft rotation to output shaft rotation may be
15 provided. Accordingly, auxiliary transmission section 16B is a three-layer
auxiliary section of the combined range and splitter type providing four selectable speeds or drive ratios between the input (mainshaft 82) and output (output shaft 20) thereof. The main section 16A provides a reverse and three potentially selectable forward speeds. However, one of the
20 selectable main section forward gear ratios, the low-speed gear ratios
associated with mainshaft gear 110, is not utilized in the high range. Thus, transmission 16 is properly designated as a "(2 +1)x(2x2)" type transmission providing nine or ten selectable forward speeds, depending upon the desirability and practicality of splitting the low gear ratio.
25 Splitter shifting of transmission 16 is accomplished responsive to
initiation by a vehicle operator-actuated splitter button 52 or the like, usually a button located at the shift lever knob, while operation of the range clutch shifting assembly is an automatic response to movement of the gear shift lever between the central and rightwardmost legs of the shift pattern and
30 across the actuation point AR, as illustrated in Fig. 2. Alternatively, splitter
shifting may be automated (see U.S. Pat. No. 5,435,212). Range shift

11 98-TRN-092
devices of this general type are known in the prior art and may be seen by reference to aforementioned U.S. Pats. No. 3,429,202; 4,455,883; 4,561,325 and 4,663,725.
Although the present invention is illustrated in the embodiment of a
5 compound transmission not having an intermediate wall, the present
invention is equally applicable to transmissions of the type illustrated in aforementioned U.S. Pats. No. 4,754,665; 5,193,410 and 5,368,145.
In the prior art, especially for manual transmissions, the splitter clutches were operated by two-position actuators and, thus, were provided
10 with a relatively small backlash {i.e., about .008-.012 inches backlash for
a clutch having about a 3.6-inch pitch diameter) to prevent unduly harsh splitter shifting. Typically, with the above backlash and the usual engagement forces, at greater than about 60 RPM input shaft synchronous error, the clutch teeth would ratchet or "buzz" and clutch engagement
15 would not occur.
As is known (see U.S. Pat. No. 5,052,535, the disclosure of which is incorporated herein by reference), allowable relative rotational speed at which the positive clutches will properly engaged (i.e., sufficient clutch tooth penetration will occur) is a directly proportional function of the total
20 effective backlash in the clutch system. The maximum allowable
asynchronous conditions at which clutch engagement is allowed is selected in view of the most harsh clutch engagement which is acceptable.
In change-gear transmissions utilizing the non-synchronized positive clutch structures, especially for heavy-duty vehicles, for a given total
25 backlash (i.e., a given maximum allowably harsh clutch engagement), the
range of asynchronous conditions at which the clutch members will engage is often narrower than desirable under certain conditions, making shifting more difficult.
According to the present invention, and as more fully described in
30 aforementioned U.S. Pat. No. 5,651,292, the interengaging clutch teeth
provided on splitter clutch 88 and on splitter gear 124 and splitter/range

12 98-TRN-092
gear 126 are of a relatively large backlash (i.e., about .020-.060 inches for a 3.6-inch pitch diameter clutch), which will assure that almost any attempted splitter shift under full force will be completed.
The clutch 88 is moved by a shift fork 98 attached to the piston
5 rod 140 of the piston actuator assembly 142 (see Fig. 4). Actuator
assembly 142 may be a conventional three-position actuator (see U.S. Pat. No. 5,054,591, the disclosure of which is incorporated herein by reference) or an actuator of the type illustrated in U.S. Pat. No. 5,682,790 or 5,661,998 (the disclosures of which are incorporated herein by reference),
10 wherein pulse width modulation of a selectively pressurized and exhausted
chamber 144 may be used to achieve the three splitter positions (L, N, H) of the shift fork.
Preferably, the splitter clutch actuator 142 will, be capable of applying a variable force, such as by pulse width modulation, of supply pressure. A
15 force lesser than full force may be utilized when disengaging and/or when
synchronous conditions cannot be verified.
The controller 48 is provided with logic rules under which, if the main section is engaged, a shift from splitter neutral into a selected target splitter ratio is initiated such that, under normal conditions, including proper
20 operator fuel control, the synchronous error (which is equal to input shaft
rotational speed minus the product of output shaft rotational speed and transmission target gear ratio) is expected to be equal to or less than a value selected to give smooth, high-quality shifts ((IS - (0S*GR)) = ERROR 25 acceleration/deceleration and actuator reaction times.
In certain situations, the logic rules will recognize operating conditions wherein the preferred synchronous window (i.e., IS = (OS*GR) ± 60 RPM) must be expanded to accomplish a splitter shift, even at the expense of shift quality. These situations, usually associated with upshifts,
30 include if shifting attempted at low engine speeds wherein expected engine
speed at shift completion will be undesirably low, if deceleration of the

13 98-TRN-092
output shaft is relatively high (dOS/dt engine is relatively low (dES/dt > REF) and/or if the absolute value of the
synchronous error is not approaching the normal value at an acceptable
rate. In the preferred embodiment, if main section neutral is sensed, the
5 splitter will be caused to engage under full force, regardless of the presence
or absence of synchronous conditions.
The position of the shift lever 31 or of the shifting mechanism 32 controlled thereby may be sensed by a position sensor device. Various positioning sensing assemblies are known in the prior art, with a preferred
10 type illustrated in allowed U.S. Serial No. 08/695,052, assigned to the
assignee of this application, the disclosure of which is incorporated herein by reference.
Referring to Figs. 5A and 5B, shifting mechanism 32 is illustrated as a single shift shaft device 160 having a shaft 162 which is rotatable in
15 response to X-X movements of shift lever 31 and axially movable in
response to Y-Y movements of shift lever 31. Mechanisms of this type are described in detail in aforementioned U.S. Pat. No. 4,920,815.
Shift shaft 162 carries the main section shift forks 90 and 92 for selective axial movement therewith and a shift block member 164 for
20 receiving a shift finger or the like. A pair of coils 166 and 168 provide a
pair of signals (collectively GR) indicative of the axial and rotational position of shaft 162 and, thus, of shift lever 31 relative to the shift pattern illustrated in Fig. 2. Preferably, the rate of change of position (dGR/dt) also may be determined and utilized to enhance shifting of the system 10.
25 By way of example, referring to Fig. 2, if shift lever position can be
sensed, the need for a fixed switch or the like at point AR to sense a
required initiation of a shift between low range and high range is eliminated.
Further, as physical switches are no longer required, the shift pattern
position at which a range shift will be commanded, AR, can be varied, such
30 as to points 180, 182 or 184, to enhance system performance under
various operating conditions.

14
If In first (1st) through fourth (4th), a shift Into high range is very unlikely and the auto range shift initiation point may be moved to position 184 (away from the expected shift lever path) to prevent inadvertent actuation of a range shift, if in sixth (6th) with a high engine speed, a shift Into high range is likely and moving the auto range initiation point to position 180 wilt allow for a quicker initiation of a range shift. Similarly, if in fifth (5th), an intentional shift into high range is only moderately likely, and the range shift initiation point may be moved to position 182.
According to the present invention, the operator is allowed to control engine fueling unless the current vehicle operating conditions indicate that his/her operation of the throttle pedal will not allow the Jaw clutches associated with the current target ratio to engage. If operating conditions, including operator setting of the throttle pedal, indicate that the operator will complete a splitter shift into target ratio, the engine will be fueled in accordance with operator throttle setting, if not, automatic engine fueling may occur, if the splitter section does engage prior to the main section (as is preferred), the operator will remain in complete control of engine fueling to complete the shift by engaging the main section. The state of engagement (i.e., engaged or neutral) of the main transmission section 16A is an important control parameter for system 10. Byway of example, if main section neutral is sensed, the splitter may be commanded to a full force engagement, regardless of the existence or absence of synchronous conditions. Also, if the main section is engaged while the splitter Is in neutral, the system wiSI not cause splitter engagement until substantial synchronous is sensed and may then initiate automatic fuel control if required. Of course, it is important to prevent or minimize false determinations of main section neutral and/or engaged conditions.
Referring to Fig.2, a first narrow band 202 and a second wider band 204 defined respectively by a first maximum value and a second maximum value of vertical displacements from the bight portion 200 are utilized are utilized to determine if the main section is or is not in neutral. The second maximum value is greater than the first maximum value, if the transmission ...

15 98-TRN-092
main section is not confirmed as being in main section neutral, the neutral
confirmation band will be the narrower band 202. This will assure that the
main section 16A is truly in neutral before declaring a main section neutral
condition. If the transmission main section 16A is confirmed as being in
5 neutral, the neutral confirmation band will be the wider band 204. This
assures that mere overshooting of neutral or raking of main section jaw clutches will not be incorrectly interpreted as a main section engaged condition.
Sensing the shift lever at point 206 will always be interpreted as main
10 section neutral, and sensing the shift lever at point 208 will always be
interpreted as main section engaged. However, if the shift lever is sensed at point 210, this will not cause a previous determination of a neutral or engaged condition to change.
Vehicle operating conditions other than or in addition to currently
1 5 engaged or neutral condition of the main section 16A may be used to vary
the width of the neutral sensing bands.
Accordingly, it may be seen that a new and improved computer-assisted, manually shifted transmission system is provided, which provides enhanced shift lever position-based sensing of transmission neutral.
20 Although the present invention has been described with a certain
degree of particularity, it is understood that the description of the preferred embodiment is by way of example only and that numerous changes to form and detail are possible without departing from the spirit and scope of the invention as hereinafter claimed.

16 We Claim:
1, A method for controlling assisted shifting in a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising:
sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from said vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than

17
said first maxim urn value, if said main transmission section was last determined to be in neutral; and
controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section.
2. The method as claimed in claim 1 wherein said transmission is a
compound transmission having a splitter section (16B) connected
in series with said main transmission section.
3. The method as claimed in claim 1 wherein said transmission is
driven by a fuel-controlled engine (12) and said input signals
include signals indicative of engine rotational speed and vehicle
ground speed.
4. The method as claimed in claim 2 wherein said transmission also
includes a range section (16B) connected in series with said main
transmission section and said shift pattern comprises at least one
first leg (3/4-5/6) for selection of low range ratios, a second leg
(7/8-9/10), parallel and adjacent to a first leg, for selection of high
range ratios, and a transition segment (200), extending
perpendicularly between said first and second legs, said transition
segment defining the vertically non-displaced position in said shift
pattern.
5. A control system for performing the method as claimed in claim 1,
comprising a transmission (16) having amain transmission section
(16A), a manually operated shift lever for shifting said main
transmission section in accordance with an established H-type shift
pattern wherein lesser vertical displacements from a vertically
centered n on-displaced position (200) are indicative of said main

18
transmission section being in neutral and greater vertical displacements from said vertically centered position are indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said control system comprising:
means for sensing values of position parameters indicative of current shift lever vertical position in said shift pattern; means for comparing said current shift lever vertical position to a variable band of vertical displacements from said vertically non-displaced position to determine if said main transmission section is currently engaged or is in neutral:
means for causing said band of vertical displacement from said vertically displaced position to have a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said first maximum value, if said main transmission section was last determined to be in neutral; and
means for controlling said transmission system as a function of the current determined engaged and neutral conditions of said main transmission section.

19
6", The control system as claimed in claim 5 wherein said transmission is a compound transmission having a splitter section (10B) connected in series with said main transmission section.
7. The control system as claimed in claim 5 wherein said transmission is driven by a fuel-controlled engine (12) and said input signals include signals indicative of engine rotational speed and vehicle ground speed.
S. The control system as claimed in claim 6 wherein said transmission also includes a range section (16B) connected in series with said main transmission section and said shift pattern comprises at least one first leg (3/4-5/6) for selection of low range ratios, a second leg (7/8-9/10), parallel and adjacent to a first leg, for selection of high range ratios, and a transition segment (200), extending perpendicularly between said first and second legs, said transition segment defining the vertically non-displaced position in said shift pattern.
9. A method for controlling assisted shifting in a vehicular transmission system as claimed in claim 1 comprising a transmission having a main transmission section, a manually operated shift lever for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertically centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are indicative of said main transmission section being engaged in a gear ratio, a sensor for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a

20
system controller for receiving input signals including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals to system actuators, said method comprising:
sensing values of position parameters indicative of current shift lever vertical position in said shift pattern;
comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged or is in neutral, said band of vertical displacement from said vertically displaced position having a first maximum value (202) if a first set of vehicle operating conditions was last determined to exist and a second maximum value (204), greater than said first maximum value, if a second set of vehicle operating conditions was last determined to exist; and
controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section.
A method for controlling assisted shifting tn a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are Indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising:
sensing values of position parameters indicative of current shift lever vertical position in said shift pattern;
comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from sald vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said First maximum value, if said main transmission section was last determined to be in neutral; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section.
A method for controlling assisted shifting tn a vehicular transmission system (10) comprising a transmission (16) having a main transmission section (16A), a manually operated shift lever (31) for shifting said main transmission section in accordance with an established H-type shift pattern wherein lesser vertical displacements from a vertical centered position (200) are indicative of said main transmission section being in neutral and greater vertical displacements from said vertically centered position are Indicative of said main transmission section being engaged in a gear ratio, a sensor (168) for providing signals (GR) indicative of the position of said shift lever in said shift pattern, a system controller (48) for receiving input signals (68) including said signals indicative of shift lever position and processing same according to predetermined logic rules to determine values of control parameters indicative of vehicle operating conditions and to issue command output signals (70) to system actuators, said method comprising:
sensing values of position parameters indicative of current shift lever vertical position in said shift pattern;
comparing said current shift lever vertical position to a band of vertical displacements from said vertically centered position to determine if said main transmission section is currently engaged in a gear ratio or is in neutral, said band of vertical displacement from sald vertically displaced position having a first maximum value (202) if said main transmission section was last determined to be engaged and a second maximum value (204), greater than said First maximum value, if said main transmission section was last determined to be in neutral; and controlling said transmission system as a function of the determined current engaged and neutral conditions of said main transmission section.

Documents:

00286-cal-1999 abstract.pdf

00286-cal-1999 claims.pdf

00286-cal-1999 correspondence.pdf

00286-cal-1999 description (complete).pdf

00286-cal-1999 drawings.pdf

00286-cal-1999 form-1.pdf

00286-cal-1999 form-18.pdf

00286-cal-1999 form-2.pdf

00286-cal-1999 form-3.pdf

00286-cal-1999 form-5.pdf

00286-cal-1999 form-g.p.a.pdf

00286-cal-1999 letters patent.pdf

00286-cal-1999 priority document.pdf

286-CAL-1999-CORRESPONDENCE.pdf

286-CAL-1999-FORM-27-1.1.pdf

286-CAL-1999-FORM-27.pdf

286-CAL-1999-PA.pdf

« Previous Patent

Next Patent »

Patent Number

202618

Indian Patent Application Number

286/CAL/1999

PG Journal Number

09/2007

Publication Date

02-Mar-2007

Grant Date

02-Mar-2007

Date of Filing

31-Mar-1999

Name of Patentee

EATON CORPORATION

Applicant Address

EATTON CENTRE, 1111 SUPERI-OR AVENUE CLEVELAND ,OHIO 44114-2584,

Inventors:

#	Inventor's Name	Inventor's Address
1	DAVID LOENARD WADAS	6300 WILLOWBROOK DRIVE KALAMAZOO ,MICHIGAN 49004-9000

PCT International Classification Number

F 16 H 63/44

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	09/053,090	1998-04-01	U.S.A.