|Title of Invention||
"MEASUREMENT SECTION FOR DETERMINING VARIOUS PHYSICAL PARAMETERS OF RAILED VEHICLES"
|Abstract||Measuring section for acquisition of different physical quantities of rail—mounted vehicles by means of different sensor systems, in particular for load measurement, temperature measurement and/or displacement measurement, which are connected to a common evaluation device (3) for the purpose of forming characteristic values from the sensor signals, characterized in that the different sensor systems (5, 11, 12, 14) are arranged within a common track section, with a combination of at least two different sensor systems being provided for the acquisition of different physical quantities.|
into electrical signThe present inverftidn relates to a measurement path for determining various" physical parameters of ailed vehicles.
Up to now, measuring sections for rail-mounted vehicles in most cases have consisted of transducers for acquisition of a particular physical quantity, the signals of which are transmitted to a special electronic evaluation device, which then forms the desired characteristic values based on these signals In this context, separate measuring devices on track sections are known, which determine, while one or several rail vehicles are passing over, their weight, and detect wheel runout./ wheel flats, travel speeds, number of axles, wheel diameters, derailed wheels, overheating of bearings and brakes or identify vehicle types. -For this purpose, transducers were usect to determine a Io3d, a displacement, a;-, temperature or a magnetic effect, which provided parameters for determination of the desired characteristic values or results.
A track section which constitutes a rail weighbridge for rail vehicles passing over it is known from WO 00/23770. In this.arrangement, several weighing sleepers arranged one behind the other, are located under the tracks of a particular track section. In these sleepers, load cells are installed, on which the tracks are supported on the sleepers. These load cells measure the vertical loads acting on the tracks when a rail vehicle .passes over as a physical quantity and convert them
als. With the help of an electronic evaluation device, characteristic values corresponding, e. g., to the axle load or the vehicle weight, may be calculated on the basis of the electrical signals. By placing several of these weighing sleepers one behind the other, measuring sections for weighing individual bogies or complete wagons are made up. Installation of such weighing devices into a track section can only be carried out by specialized weighing equip-ment manufacturers, which means that the first thing to be done is the provision of access for set-up vehicles. Since today these rail weighbridges are all operated with electronic devices, power supply lines and connecting cables to; the evaluation devices must be laid at the corresponding track sections, which often entails costs and complexities by far exceeding those of the weighing system itself. As a ^consequence, for reasons of economy such measuring sections for weight determination are usually installed into sidetracks only, where the required infrastructure already exists, so that a large-scale axle load determination by means of such measuring sections is usually not possible.
For the detection of runout and flats on rail vehicle wheels, a special measuring section is known from DE 44 39 3:42 Al, in which the reaction forces of the sleepers are measured on four successive sleepers. For this purpose, eight strain gauges are applied on the rail foot supported on the sleeper, which are connected into a Wheatstone bridge, and all measuring points are connected to a specific circuit arrangement for evaluation. In this circuit arrangement used for evaluation, the vertical wheel contact forces of each measuring point are determined as characteristic values on the basis of the corresponding electrical signals. A particular deviation from a constant value translates into a certain degree of runout or a wheel flat, which can be indicated and signaled. Since such wheel imperfections and flats may lead to considerable track
, especially in case of high transit speeds, such detection systems should be integrated into any high-speed .track section and each train in this section should be monitored and identified in order to reduce its speed or stop the train if necessary. .However, since such high-speed sections are! usually outside railway station areas and outside developed plots, installation of such detection systems usually involves Ihigh costs and complexities for providing access, for establishing the required power supply system and for linkage to central monitoring and control centres. For this reason, the described measuring sections have been used quite seldom up to now, so that wheel flats and runout are usually detected during stationary maintenance activities only.
From DE 43 27 674 C2, a device for recording preferably quickly rotating rail vehicle wheels is known, with thje help of which the axles driving on a track section are counted and their speed and direction of travel is measured. For this purpose, a track section delimited by two wheel detection points is provided with two wheel detectors arranged at a distance and located at least at each of the wheel detection points. The wheel detectors may work in accordance with different physical principles. They may consist of mechanical switching devices, eddy-current transducers or optical switching devices. Whenever a vehicle wheel passes one of the two Wheel, detection points, the two wheel detectors generate twoi successive electrical systems, which are supplied to an evaluation device provided for the corresponding track section. The evaluation device consists in a program-controlled computer, in which the two electrical switch signals are temporarily stored and evaluated in such a way that corresponding characteristic values are obtained for the direction of travel, the transit speed and the number of axles entering and leaving the track.section. During this process, messages signalling that the section is free or occupied are to be created on the basis
of the axles entering and leaving the sections, in order tp prevent accidents with following trains. To ensure the safety of the railway traffic, such axle counting devices should be provided one after the other in the entire track system spaced out at the braking distances. This involves high costs and complexities, since transducers must be arranged in pairs along the entire track system, and these must be connected to central monitoring and evaluation systems. However, even this would not be enough to detect safety-relevant damage; to the undercarriage or the wheels of the trains in transit.
A method and a device for monitoring of a preferabl^f rail-mounted vehicle is known from WO 00/51868. In said method, load-dependent quantities on the undercarriage of a vehicle are measured, -and from these values, location and speed-dependent characteristic values for a particular measuring section are formed, which are then compared with replresenta-tive characteristic values of the new vehicle on this measuring section. In case of a predefined deviation, it is concluded that a derailing has taken place or damage to the undercarriage has occurred. For this purpose, accelerometers, relative-movement transducers, temperature sensors and strain gauges are provided on the undercarriage of the raill-mounted vehicle, which measure, during transit on a particular track section, e.g. the distance of the undercarriage to fthe rail, the temperature at the wheel bearings or the brakes br the strain of an axle suspension; based on these measured values and taking account of the travel speed and the properties of the track, they determine vehicle damage or derailing occurrences. For monitoring the entire traffic on a large! scale, each rail-mounted'vehicle or train must be equipped with such monitoring devices. To this end, first the representative data of the entire track system must be acquired and stored into the corresponding evaluation devices. This means that each time the stored measuring sections are changed, the represen-
|j|ative values must be recorded newly for a reliable detection . of any deviation. The repeated acquisition of such representa-tive values is laborious and expensive, which can only! be justified in case the potential danger is quite high. However, such equipment can only detect damage to the vehicle wheels once the wheel has derailed, so that tire breakage, stjrong runout or wheel flats are actually detected too late.
Therefore, the invention is based on the problem of creating a measuring section with the help of which various operation or safety-relevant data of a rail-mounted vehicle passing; over it can be acquired for different characteristic values, and this
should be possible with a minimum expenditure of money work to be spent on the supply infrastructure.
This problem is solved by the invention set forth in patent claim 1. Further developments and advantageous embodiments of the invention are described in the subclaims. !.
An advantage of the invention is that by measuring different physical quantities on a common measuring section, separate infrastructure measures may be spared. For the installation of different sensor systems in a single measuring section^ even on remote track sections, only one access way, one power supply and one signal transmission system are required. F^irther-more, as a result of the common evaluation of the different sensor signals, additional characteristic values relevant for safety and operation may be determined, which is only possible with an advantageous effect by combining the different;sensor signals. It is also possible to determine the same characteristic values on the basis of different physical quantities, in which case only those sensor signals involving the lowest evaluation expenditure are used advantageously.
Another advantage of the invention is that by combining and integrating the different sensor systems within one!measuring section, a large number of safety-relevant and economically relevant data of both rail vehicle and track, section may be acquired and evaluated. Due to the fact that all sensor systems "are to be installed on the common sleepers or the rails of a limited track section, the expenditure for installation is very low and the time required for installation leads to a very short interruption of the railway traffic only.! The common monitoring of different safety-relevant characteristic values also enables early detection and identification of dam-
age to the rail vehicle in an advantageous manner, thus making it possible to initiate preventive remedies.
The invention is further illustrated with the example of an embodiment which is represented in the drawing. The Idrawing shows a schematic representation of a top view on a Measuring section 1 for rail-mounted vehicles. The measuring section 1 consists in a track section, on the rails 2 and the Isleepers 4 of which load transducers 5, temperature sensors 11, 12 and magnetic field sensors 14 are arranged, which are connected to a common evaluation device 3 and a common power supply 9.
The measuring section 1 comprises a track section with an approximate length of preferably 4 m, which as a general rule comprises seven sleeper areas. This measuring section 1 contains under each rail 2 seven load transducers 5 supporting the rail 2 on the sleepers 4 and by means of which the wheel contact forces of a rail vehicle in transit may be measured over at least one wheel revolution. The load transducers .5.are preferably designed as shearing force transducers, which are arranged in a recess under the rail head or under .the entire rail 2. The transducers 5 are friction-locked to the rail 2 . and the sleeper 4. Each load transducer 5 contains at least four strain gauges, which are connected into a Wheatstone
fridge and are supplied with a direct voltage or carrier fre
quency voltage from a common power supply unit 9. In ai deviat
ing,, special embodiment, the load transducers 5 may also be
arranged in the sleeper 4, in the space between the sleepers
or outside the space between the sleepers. The wheel contact
force may also be acquired by means of accelerometers and con
verted into a force. ;
The load transducers 5 are connected to a central evaluation device 3, preferably via a switching mechanism 6 arranged at each sleeper. The evaluation device 3 contains an input circuit lr in which the signals of each load transducer 5:are amplified separately or in interconnectable groups. These amplified analog signals are subsequently converted into digital values in one or several converter circuits 8. All electronic circuits in the evaluation device 3 are connected with;the central power supply circuit 9, which also supplies th^ power for the load transducers 5 of the measuring section 1 yia the evaluation device 3. For further evaluation, the digitaiized measured values from the load transducers 5 are transmitted to a program-controlled microprocessor circuit 10, which is arranged somewhere near the measuring section 1 or in a central monitoring centre. If the distance to the measuring section 1 is larger, the microprocessor circuit 10 of the evaluation de-•vice 3 is connected to the input circuit 7 and the converter circuit 8 via interface circuits. The evaluated signal^ may also be transmitted, preferably via a bus system, to further program-controlled computer systems for further processing, in which the characteristic values calculated from of the transducer signals can be indicated or signaled.
In the:space preceding the first and the space following the .last sleeper 4 of the measuring section 1, load transducers 13 which are designed as shearing force transducers are arranged preferably in the neutral phase of each rail 2. In a borehole,
these are friction-locked to the stem of the rail and, when a vehicle wheel passes over them, they supply a signal which corresponds to the shunt force. This signal is used!for correction of the shunt force effect of the wheel cont4ct forces and as a rail switch. The four shearing force transducers 13
are also connected to the common evaluation device 3 and the common power supply device 9 via the common switching devices 6. These shearing force transducers 13, too, contain separate input circuits and get a direct voltage or carrier frequency voltage supply. The digitalized shearing force transducer signals, too, are then transmitted to the common microprocessor circuit 10 and subjected to a program-controlled evaluation.
Further, the measuring section 1 contains temperature sensors 11, 12 in a common area on one or several of the sleepers 4. At least between the rails 2, one or two temperature sensors 11 are arranged, which record the temperature-dependant infrared radiation from the disc brakes of a railway wagon. However, the temperature sensors 11 may also be arranged in the sleepers, in the space between the sleepers or outside the space between the sleepers in a common track section. The sensors 11 with their connecting cables, are linked to the central evaluation device 3 and the power supply device 9 via the switching device 6. The recorded temperature signals, too, are transmitted to separate input circuits 7, amplified and subsequently digitalized and transmitted to the common microprocessor circuit 10 for further evaluation.
To measure the temperature of wheel bearings of rail-mounted • vehicles, at least two further temperature sensors 12 are provided at the sleepers 4, preferably arranged at the ends of the sleepers, over which the wheel bearings move. These temperature sensors 12 for recording the wheel bearing temperature, too, get their power supply from the common power supply
9 and their signals are also transmitted to the common evaluation device 3.
On at least one of the two rails 2, a magnetic field siensor device 14 is arranged in addition, the main purpose of! which is determination of the wheel diameter. This sensor device 14 comprises a demagnetization device 15, a magnetization! device 16 and a magnetostrictive position sensor device 17, which are arranged as close to one of the rails 2 as possible. The demagnetization device 15, by means of which a passing vfehicle wheel is first demagnetized to prevent distortion of the subsequent measuring value, is preferably arranged on raiJL 2, preceding the first sleeper 4. This demagnetization device 15 works with demagnetizing magnetic fields, which cover the vehicle wheel as a whole or which are arranged along the rail, thus only demagnetizing the wheel flange during rolling.
The magnetization device 16, by means . of which a circuijnferen-tial segment of a ferromagnetic vehicle wheel passing over the magnetization device 16 is magnetized, is preferably mounted on the first sleeper 4. When the vehicle wheel passes over, this magnetized circumferential segment hits the rail 2 again in a particular point.
Therefore, for measuring the wheel circumference, the magnetostrictive position sensor 17 is arranged alongside the rail 2 in a tubular body, and this sensor comprises, in an active measuring range, a measuring rod linked to a sensor head. In the sensor head, a signal converter is provided, which generates, in the measuring rod, a displacement measurement of the wheel circumference from the magnetic influence by the magnetized wheel segment. The sensor head is preferably arranged in a common housing together with the magnetization device 16, but may also be arranged separately in another place along the rail 2. The wheel diameter may also be measured by other non-
contacting displacement transducers, which scan the;wheel with
the help of laser or other light beams-and convert the value
into a length measurement value. The magnetic fieldsensor de
vice 14, too, is connected to the common power supply 9 and
the common evaluation device 3 via the common switching device
6. - -
By combining the different sensor systems with a conjimon evaluation system for the recorded signals, not only operation-relevant characteristic values such as wheel Iqad, axle load weights or track load may be determined by mearjs of such a measuring section, but also safety-relevant characteristic values such as overheating of bearings, wheel flats jor slip-ping wheels. Since the load transducers 5 are preferably arranged in a recess of the rail 2 under the rail head, all sensor systems 5; 11, 12; 14 may be arranged advantageolusly on
conventional sleepers 4 or conventional rails 2 with|in a common track section. Whether the different sensor systjems are mounted directly on the sleepers 4 or on the rails 2 is not relevant as long as they are arranged close to them within a limited common track section. By this arrangement, common power supply 9 and evaluation devices 3 can be used, so that employment of this kind of measuring section is also! economical on normal railway lines or high-speed lines.
When a rail-mounted vehicle passes over the measuring section 1, the first two load transducers 5 on the first sleeper 4 generate electrical signals which are proportional to the corresponding vertical wheel contact force of the two vehicle wheels passing over-the transducers. The.signals of each of the two force transducers 5 are amplified"via its own input channel in the input circuit 7 and converted into digital values by the downstream analog-digital converter 8, and these digital values are transmitted to the microprocessor circuit 11 of the evaluation device, where they are temporarily
. Such a signal acquisition is also effected by the remaining six load transducers 5 of each rail 2, and thujs all scanned vertical wheel contact forces are available, after one wheel revolution, in the evaluation device 3 where they are temporarily stored. However, to simplify the circuitry, several load transducers 5 may be interconnected to form comparable groups and to be evaluated in groups.
In the program-controlled evaluation device 3, which may also be designed as a personal computer, a mean value is calculated from the scanned wheel contact force values, which corresponds to the characteristic value of the wheel weight and represents, by corresponding multiplication, a characteristic value of the axle or wagon weight. When a bogie of a rail-mobnted vehicle passes over, a characteristic value for the bogie load is formed from the axle loads determined either one after the other or simultaneously. To distinguish between individual load measurement and bogie measurement, additional wagon identification takes place during transit. The type of a wkgon or any other rail vehicle is identified, among other factors, on the basis of its axle base (wheel center distance) and/or its wheel diameter.
The axle bases are determined, preferably, by the shearing force transducers 13 at the beginning and at the end of measuring section 1, which are then used as rail switches.; However, these switch signals may also be generated by the load transducers 5 in the first and the seventh sleeper 4. When a vehicle passes over, the rise of an edge or of a signal characteristic of the shearing force signal is measured and its development-versus-time history between the shearing force transducers 13 at the beginning and at the end of the measuring section 1 is determined. Based on the known distance on measuring section 1, the evaluation device 3 determines a characteristic value for the transit speed. Then, the axle
base of the vehicle wheels passing over is calculated from the transit speed and compared with the known axle, bases stored in the evaluation device 3; based on this comparison, e.g., the corresponding wagon type with individual axles or ..bogies is identified. In measuring sections without shearing force sensors 13 and without load transducers 5, identification of wagons may also be effected with the help of the magnetic field sensor device 14 or other non-contacting wheel diameter measuring devices. The magnetic field sensor device 14 may be used to determine the axle base, the transit speed and the wheel size, and on the basis of the characteristic values of these parameters, the corresponding wagon type can be determined in the evaluation device 3.
On the basis of the wagon type identification and thje temporarily stored axle loads and wheel loads, the total weight as the sum of the individual weights, the axle weight and the axle load distribution are calculated in the evaluation device 3 as characteristic values. In addition, the permitted maximum wheel weights and maximum total weights for the individual wagon types are preset in the evaluation device 3, and in case one of these values is exceeded, this will ,be indicated or otherwise signaled. To improve the accuracy of these weight values, a correction may take place in the evaluation device, which is effected by means of the shunt forces of the measuring section provided in the track route structure without interruption. The correction of the shunt force effect,.the influence of which has been determined before by means of calibration values, is calculated in the evaluation device 3 with the help of the signals from.the shearing force transducers 13.
Surprisingly, it has been demonstrated that by determining the wagon weight, also the number of persons in a wagon pr on a train may be counted. For this purpose, .the wagon or! train
with a known number of persons is determined and stored in the evaluation device 3 as reference value. In subsequent, regular transits, the actual weight is compared with the reference weight in the evaluation device 3, and on the basis of the deviation, the number of persons in the wagon or on the train is calculated, which is an important operation-relevant characteristic value necessary for capacity planning, and which can be determined in this manner quite easily iiti each transit.
However, the wagon type identification may also be implemented by coding data on the corresponding wagon, which can be sampled. Stored wagon data may be sampled when a train passes over with. the help of magnetic strips or read-only memories in a non-contacting manner by means of an additional sens|or system in the measuring section 1, and the sampled data can then be transmitted to the evaluation device 3.
In case of a measuring section 1 located in a normal railway line, not only the wagon and train weights are determined, but also the total pass-over weight as the sum of the individual weights, which represents a characteristic value for the total load of the track section. When a preset maximum load is reached, this is indicated or signaled by the evaluation device 3, and then checking, tamping or maintenance measures on the track section may be initiated.
By determination of the vertical wheel contact force during a complete revolution of the wheel on the measuring section with a length of approx. 4 m, each of the seven load transducers 5 also records differences of the wheel contact force. For this purpose, the transducer signals of each of the load transducers 5 passed over one after the other are temporarily stored in the evaluation device 3 and on this basis, their mean value is calculated for each rail. A defined deviation of one or
several transducer signals from the calculated mean;value is, in most cases, an indication that the wheel has a flat spot or shows inadmissible runout, in which case the corresponding characteristic value may be indicated or this may be signaled. A particularly large deviation from the mean value may also mean that a tire breakage has taken place, which may be indicated and/or signaled as such immediately. Since the defective wheel can be identified both by the wagon identification system and by the measured transit time, such a train may be stopped or the damage may be indicated to the chief conductor of the train concerned.
With the acquisition taking place through each individual load transducer 5 in its own input channel, it is also intended to form the sum of the wheel contact forces of each -track side during each transit of a train. A major deviation between the two rails is usually due to a corresponding crosswinjd load, which constitutes a potential danger, in particular |in case of high train speeds. For this reason, such crosswind loads may be indicated, and this can be used to reduce the train speed by informing the chief conductor of the train. Within the measuring section, also -a wind velocity indicator may be arranged, with the help of which the determined weight characteristic values may be corrected by the wind force proportion.
In case of uninterrupted rails,-the shunt force effect occurring in the direction of travel is' determined by the shearing force transducers 13 at the beginning and at the end of the measuring section. For this purpose/ a correction characteristic is formed in the evaluation device 3 from the shunt force signals and the reference values determined by means:of a prior calibration, and this correction characteristic is linked to the determined weight values. Thus, a higher accuracy of the weight measurement is obtained. The forces in the direction of travel measured by the shearing force transducers
also result in a characteristic value which is proportional to the bearing load of the rail bearing on the sleepers 4. For this reason, the evaluation device 3 provides for separate measurement and indication of this bearing load. In high-speed trains, exceeding of the permissible bearing or sleeper load may be prevented by reducing the travel speed.
The temperature sensors 11 arranged between the rails 2 on the sleepers 4 on the measuring section 1 are arranged below the drum or disc brakes of the rail vehicles and are directed towards the brakes in such a way that they measure the radiant heat or infrared radiation arising as a result of the heat. On the basis of a known distance between the transducers jll and the brake disc or brake drum and the transducer signals, a temperature characteristic of the brake disc or brake drum is calculated in the evaluation device 3. Since the brakihg power strongly decreases with increasing brake disc temperatjure, 3 limit values are preset in the evaluation device 3; ini case they are exceeded, overheating will be indicated or signaled.
Temperature sensors 12 of the same kind are also provided in the two end zones of one of the sleepers 4 within the measuring section 1, which are in most cases arranged below the wheel bearings passing over. These temperature sensors 12 are directed towards the wheel bearings in such a way that , they measure the heat-caused infrared radiation from the wh£el bearings. Based on the preset distance from the bearings and the determined temperature signals, a characteristic value for the bearing temperature of each wheel bearing passing over is calculated in the evaluation device 3. Since overheated wheel bearings can be a sign of a bearing damage, exceeding of a preset limit value is indicated or signaled. Due to the wagon and train identification carried out before, the defective bearing as well as an overheated brake may be identified and indicated in a monitoring centre in the chief conducto^' s
cabin. By means of such temperature sensors 11, 12,. the ambient temperature as well as the rail temperature, which is important for operational reasons, may be measured at the same time and taken into account when operation-relevant characteristic values are calculated, or they may be indicated in a monitoring centre.
With the help of the magnetic field sensor device 14, which is additionally arranged within the measuring section 1, also the wheel diameter is determined when a wheel passes over. For this purpose, the demagnetization device 15, by whidh any residual magnetization of the ferromagnetic vehicle whleel is eliminated, is arranged preceding the first sleeper A of the measuring section 1 at or alongside at least one of the rails 2. In this process, preferably the tire is lead past a magnetic alternating field of the demagnetization device 15 during at least one revolution of the wheel.
On the first sleeper 4, a magnetization device 16 is arranged downstream, by which a partial segment of the vehicle wheel passing over it is magnetized. For this purpose, at least the wheel tire passes a strong electromagnet, and is magnetized transiently by a current pulse. In the following section, the magnetostrictive position sensor device 17 is arranged along the rail-2 at least in a range of 2 to 4 m from the magnetization point. When the magnetized wheel segment hits the rail 2, a magnetic influence arises in the adjacent measuring rod consisting of ferromagnetic material.
Simultaneously, a short current pulse is emitted at regular intervals from the sensor head on the measuring rod, which generates another magnetic field around the latter. If the two magnetic fields enter into contact, a mechanical twist and deformation (torsion) arises in the measuring rod at the point of the segment where the magnetic fields enter into contact.
a result, a structure-borne ultrasonic wave is generated in the measuring rod, which runs from the point where it arises to both ends of the measuring rod.
Detection of the ultrasonic wave is effected in the signal
transformer, in which a converter system is provided above the
measuring rod and which comprises a stationary permanent mag
net and an inductive detection coil, in which a magne-
torestrictive metal strip is arranged. In the metal strip, the
returning structure-borne ultrasonic wave effects a permeabil
ity change, which leads to an electrical response signal in
the detection coil. In an electronic circuit of the transducer
head, a characteristic value, which represents a displacement
measurement and is proportional to the wheel circumference, is
obtained from the pulse-time delay of the torsion pulse with
the help of the constant ultrasonic speed. I
This characteristic value is then supplied to the evaluation device 3 via a common switching device 6. In the evaluation device 3, the wheel diameter is calculated from the circumference characteristic. On the basis of the wheel diameter, also the distance to the brake discs and the wheel bearings may be determined, if this has not been preset, since these values are required for precise temperature measurement at the wheel bearings and the vehicle brakes. At the same time, a maximum permissible wheel or axle load, which is checked by comparison with the determined wheel contact force values, is obtained from the wheel diameter; if the value is exceeded, this will be indicated or signaled.
The wheel size and the determined wheel bases may also be used for even more reliable wagon identification in the 'evaluation device 3, if the wheel bases required for identification differ only slightly. Since the magnetic field sensor device 14 generates a signal each time a vehicle wheel passes ovqr it,
it is also used for axle counting. For this purpose,; the sig-"nals are added up and indicated in the evaluation device 3, as in case of a rail switch when a train passes over it:. If the number of axles of a train is known, this may be used to detect and signal the derailing of an axle or. bogie or the loss of one or several wagons by means of a comparative calculation in the evaluation device 3.
If several measuring sections 1 are arranged one after the other at a distance, this may also be used to monitor the axles entering and leaving the track section. Furthermore, the magnetic field sensor 14 also detects slipping vehicle wheels. For this purpose, a limit value for the wheel circumference which exceeds any existing wheel diameter is entered .in evaluation device 3. If the magnetized wheel segment is not detected at this distance, this constitutes a characteristic value for a slipping vehicle wheel and may be indicated or signaled as such. However, a slipping wheel may also be determined by means of a comparison of the diameters or wheel circumferences of all wheels of a wagon. In this case, the slipping wheel is indicated or signaled in the evaluation device 3 if a preset deviation from the mean value of all wheel diameters of a wagon is detected.
Such measuring sections 1 may be integrated into the entire railway network at regular distances, thus enabling reliable and comprehensive monitoring and acquisition of operating data of the track and the vehicles operating on the corresponding lines. In particular the combination of force-measuring and temperature-measuring sensor systems-5, 11, 12 on a measuring section 1 provides for a monitoring.system which may raise the safety of track lines considerably. At the same time,.operational data may be acquired with the help of which a more efficient capacity planning for the line is possible.- In .particular, operation may be controlled in such a way that damage
(Recurs less frequently and maintenance costs are reduced.. Particularly the combination with a magnetic field sensor device 14 has the advantage that it allows data for train identification, axle and speed values as well as the maximum admjissible. axle load to be determined with high precision and in a quite easy manner, thus improving the possibilities of evaluating operational and safety-relevant data as a whole, also with regard to the speed of evaluation.
For acquisition of several different physical quantities, the measuring section may comprise any combination of sensor systems, as long as they supply the desired characteristic values easily and cost-effectively. In particular for high-speed lines, combinations of load transducer and temperature: sensor systems are advantageous, since they enable the determination of the safety-relevant characteristics of runout, tire; breakage, brake overheating and axle overheating in an easy: manner. However, to monitor freight traffic on a track, the combination of load transducers, temperature sensors and wheel-diameter measuring systems is of particular advantage, since overload to the track as well as overload to the rail vehicles may be prevented, especially if the axle load distribution and exceeding of the maximum permitted wheel load as well as the total load are monitored. Nevertheless, combinations of just temperature and wheel diameter measuring systems are possible as well, by which the characteristic values of heat load of brakes and bearings as well as exceeding of the maximum permitted speed and slipping wheels may be detected.
Measuring section for acquisition of different physical quantities of rail-mounted vehicles.
1. Measuring section for acquisition of different physical quantities of rail—mounted vehicles by means of different sensor systems, in particular for load measurement, temperature measurement and/or displacement measurement, which are connected to a common evaluation device (3) for the purpose of forming characteristic values from the sensor signals, characterized in that the different sensor systems (5, 11, 12, 14) are arranged within a common track section, with a combination of at least two different sensor systems being provided for the acquisition of different physical quantities.
2. Measuring section according to claim 1, wherein the different
sensor systems (5, 11, 12, 14) are arranged on common sleepers (4)
and/or rails (2).
3. Measuring section as claimed in claims 1 or 2, wherein a
combination of different sensor systems (5, 11, 12, 14) comprises at least
one for load and temperature measurement or at least one for load,
temperature and displacement measurement.
4. Measuring section as claimed in one of the preceding
claims, wherein between the rails (2) and the sleepers (4) load
transducers (5) are provided, by which the vertical wheel contact forces
of vehicle wheels at standstill or in transit may be determined, on the
basis of which the evaluation device (3) determines various load—
5. Measuring section as claimed in one of the preceding claims,
wherein shearing force sensors (13) are provided as load transducers at
the beginning and at the end of the measuring section (1), preferably in the neutral phase of the rail (2), and in that the evaluation device (3) determines, on the basis of the signals supplied by these transducers, characteristic values for correction of the shunt force effect.
6. Measuring section as claimed in one of the preceding claims,
wherein the evaluation device (3) determines, on the basis of the signals
of at least one or several shearing force sensors (13) and/or load
transducers, characteristic values for the number of axles passing
over and/or the transit speed.
7. Measuring section as claimed in one of the preceding claims,
wherein within the track section of the measuring section (1), a sensor
system (11, 12) for temperature acquisition is provided, and in that the
evaluation device (3) determines, based on the signals of this sensor
system, characteristic values for the thermal load of defined parts of
vehicles in transit, of rail parts and/or areas of the surrounding
8. Measuring section as claimed in claim 7, wherein the sensor
system for temperature acquisition comprise at least one temperature
sensor (11, 12), which is arranged on one of the sleepers (4) within the
track section of the measuring section (1) and which detects the thermal
load on the vehicle brakes and/or the wheel bearing by converting the
infrared radiation into electrical signals.
9. Measuring section as claimed in one of the preceding claims,
wherein within the track section of the measuring section (1), a sensor
system for displacement measurement with a magnetic field sensor
device (14) is provided, which measures, when a ferromagnetic vehicle wheel passes over it, the circumferential length of the latter, on the basis of which the evaluation device (3) determines at least one characteristic value for the wheel diameter and/or the number of axles passing over.
10. Measuring section as claimed in claim 9, wherein the magnetic
field sensor device (14) at the same time records the time which the
circumference needs to roll over the rail (2), on the basis of which the
evaluation device (3) determines a characteristic value for the transit
11. Measuring section as claimed in claim 9 or 10, wherein the
magnetic field sensor device (14) comprises a demagnetization device
(15), a magnetization device (16) for magnetization of a wheel segment
passing over it and a magnetostrictive position sensor (17) to detect the
magnetized wheel segment hitting the rail (2), which are arranged
alongside at least one rail (2).
12. Measuring section as claimed in one of the preceding claims,
wherein the different sensor systems (5, 11, 12, 14) are connected to a
common evaluation device (3), which determines, on the basis of the
different sensor signals of the same or different sensor systems (5, 11,
12, 14), various characteristic values representing safety and/or
operation—relevant data of the rail vehicles in transit and/or a section of
a preset track section.
13. Measuring section as claimed in one of the preceding claims,
wherein a common power supply device (9) is provided for the power
supply of the different sensor systems (5, 11, 12, 14) and the evaluation
device (3) or at least parts of an evaluation device.
14. Measuring section as claimed in one of the preceding claims,
wherein the evaluation device (3) comprises an electric input circuit (7),
an analog-to-digital-converter circuit (8) and a program — controlled
microprocessor circuit (10), which is designed in such a way that it links
the measured values obtained from the different sensor signals by means
of arithmetic operations in such a way that the previously defined
characteristic values may be determined on this basis.
15. Measuring section as claimed in one of the preceding claims,
wherein the evaluation device (3) is designed in such a way that it
samples the different sensor systems at certain intervals at least during
transit of at least one or several rail vehicles, and in that it digitalizes
and stores the values temporarily and links them with the help of preset,
stored parameters or characteristic values by means of arithmetic
operations in such a way that the results represent the desired operation
and safety-relevant data of the vehicle or the track section.
16. Measuring section as claimed in one of the preceding claims,
wherein in the evaluation device (3) , limit values are preset as pre-stored
parameters or characteristic values, which are compared with
corresponding in measured and/ or determined characteristic values, and
in that in case these limit characteristics are exceeded, this is indicated
and /or signaled.
17. Measuring section as claimed in one of the preceding claims,
wherein it comprises several measuring sections (1) of the same kind
which are arranged in different track sections and which have common
evaluation and/or indication devices.
|Indian Patent Application Number||3768/DELNP/2005|
|PG Journal Number||36/2009|
|Date of Filing||25-Aug-2005|
|Name of Patentee||SCHENCK PROCESS GMBH|
|Applicant Address||LANDWEHSTRASSE 64293 DARMSTADT, GERMANY.|
|PCT International Classification Number||B61L 23/00|
|PCT International Application Number||PCT/EP2004/001353|
|PCT International Filing date||2004-02-13|