Title of Invention

METHOD FOR TREATING ERRORS IN ELECTRONIC CONTROL UNITS

Abstract A method for error processing in electronic controllers (6), in particular in motor vehicles is disclosed, whereby errors determined on each vehicle start are permanently written in error memory(12). On repeated recognition of similar errors, an error counter (18), provided for said error, is increased. In the case where it is determined that the error counter (18) has reached a pre-determined state on a renewed vehicle start, a special programme poor maintenance is launched, which only permits the start of the monitored function when further testes are carried out and completed. Safety is thus increased, in particular with poorly maintained vehicles.
Full Text METHOD FOR TREATING ERRORS IN ELECTRONIC CONTROL UNITS
Description
The invention relates to a method, for treating errors in electronic control
units, especially in motor vehicles.
The electronic devices contained in modern motor vehicles, such as electronic
engine controllers, anti brake-lock systems, stability controls, etc., relate for
the most part to applications that are critical to safety. This means that the
vehicle can be exposed to dangerous situations in the event of a malfunction
of the control unit or of the components associated therewith.
The control units must therefore function extremely reliably and must be
continuously monitored for fault-free operation. Such monitoring must cover
both the control unit itself and the associated peripherals, or in other words
connected sensors, actuators and solenoid valves as well as the cabling
thereof.
In modern electronics equipped with microcontrollers, such monitoring is
largely ensured by self-tests.

In the case of anti brake-lock systems (ABS), for example,
simple tests known as static tests are performed for cable
breaks and short circuits as soon as the ignition is turned
on. When the vehicle starts to move, all wheel-speed
sensors are then checked for functional capability and
compliance with limit values. During driving, further tests
are initiated by the microcontrollers contained in the
electronics.
By this self-diagnosis, as it is known, the control units
of the various systems installed in the vehicle are capable
of recognizing errors and reacting appropriately to them.
The detected errors are also stored in memory together with
information such as error type, error frequency and
boundary conditions, such as the temperature prevailing at
the time. Subsequently these data can be retrieved in the
shop, using a tester connected to the vehicle bus, thus
greatly facilitating error elimination and repair.
Simple errors may also be indicated directly inside the
vehicle by means of an error light.
Technical features of self-diagnosis of electronic control
units in motor vehicles are explained in greater depth in,
for example, the article entitled "Self-diagnosis of
electronic control units in motor vehicles" [in German],
VDI-Berichte No. 612, 1986, pages 361 to 373.

If an error is detected by the foregoing tests during
driving, the control unit may react to it in various ways.
For example, an emergency-operation program that permits
limited functioning of the faulty unit may be started.
Critical errors are generally indicated directly to the
operator by a warning light. In this way he is prompted to
have the error repaired as soon as possible in the shop.
In response to these critical errors, the control unit may
even disable part of its own operation as an emergency
measure, for example by disconnecting an output stage, in
order to prevent incorrect reactions that may be dangerous
for the vehicle.
Finally, it is also important to ascertain whether the
error is of static or sporadic nature. Static errors can be
newly recognized by the electronic check at the start of
every trip. In contrast, sporadic errors occur only now and
then. They can be caused, for example, by an intermittent
contact. Both types of errors are stored in the error
memory mentioned hereinabove.
If, after a single occurrence or prolonged sporadic
occurrence, an error has no longer been detectable for a
relatively long time, the error in question can also be
deleted from the error memory. Under these circumstances,
it is assumed that, for example, an intermittent contact is

no longer present, or that a different error has since been
eliminated in the shop but has inadvertently not been
deleted from the error memory.
German Patent 4118692 C2 further teaches the use of an
error-time counting device in order to store also the
respective time interval in which an error is present. Such
an error is then permanently input into an error memory
when it is present over more test-time intervals than
specified for that error.
An existing error is newly recognized by the error test
described in the foregoing whenever the vehicle ignition is
turned on. Each time, therefore, the electronics assume
that the vehicle is error-free. In contrast, no record is
kept of whether a static error already present in the error
memory will always be newly recognized over a prolonged
time period. This is the case if, after an error has
occurred or after the error light has turned on, the
operator does not seek out a shop to eliminate the error as
soon as possible, even though he is actually presumed to
have done so, but instead no longer concerns himself with
eliminating the error. This is known to happen in countries
with too few shops or with poorly equipped shops, such as
in East Europe or Africa.
Unfortunately, such irrational behavior of the operator
leads to increasing problems. Thus multiple errors, whose
effects on the vehicle are difficult to foresee, can

develop over time. Furthermore, if the poorly maintained electronics in question
fail to function in emergencies, the vehicle manufacturer can be exposed to
product liability risks. Under these circumstances, it is then difficult for the
vehicle manufacturer to prove that the failure of its electronics to function is
merely the consequence of lack of maintenance.
The object of the invention is to provide, for cases of obstinate disregard of an
error indication, such as a warning light, a method that precludes incorrect
functioning of the electronics in question and serious consequential damage
caused thereby.
This object is achieved by the method, according to the invention, for treating
errors in electronic control units, especially in motor vehicles, with an error-
recognition program, with an error memory for storage of permanent and
sporadic errors, and with an error indicator or output having the following
features :a) permanent errors detected when the vehicle starts to move are
written into the error memory (12), b) when errors of the same type are
recognized repeatedly, the count of an error counter (18) allocated to this error
in the error memory (12) is incremented by a predetermined value in each case,
c) if, when the vehicle starts to move once again, it is found that the count of the
error counter (18) has reached a predetermined value for a particular error, a
"Poor maintenance" special program takes over, d) the "Poor maintenance"
special program then disables starting of the function being checked until
expanded tests have been performed and passed. Expedient improvements of
the method are described hereinafter."
The inventive method will be explained in more detail hereinafter on the basis of
a drawing. The (single) Fig. 1 shows a schematic diagram of an electronic
control unit of a motor vehicle, which unit is connected to sensors and
actuators.
Control unit (6) schematically illustrated in Fig. 1 comprises a microcontroller
(7) with analog-to-digital (A/D) converter (8), an error memory (12)
in the form of an EEPROM connected to microcontroller (7) and
containing an error counter (18), a watchdog (9) for checking the run

time of microcontroller (7), a driver stage (10) for
activating the connected actuators and a feedback stage
(11) for communicating feedback data from the actuators.
In the present case, a positioning motor (13), a solenoid
valve (14) and a vacuum pump (15) are connected as
actuators to control unit (6) . Examples of feedback data
include the position of positioning motor (13), the
position of solenoid valve (14) and the initial pressure of
vacuum pump (15). An error indicator (16) to signal errors
to the operator is also connected to microcontroller (7).
Moreover, microcontroller (7) is connected to a serial
interface (17), via which error data and other data can be
read out to a shop by using a special tester. Furthermore,
a vehicle data bus can be connected to interface (17) in
order to link control unit (6) with the electronics of
another vehicle, in order to communicate therewith and, for
example, to exchange data used in common.
A voltage supply (5) and sensors (1) to (4) are connected
to the input side of control unit (6). Sensors (1) and (2)
transmit digital values directly to microcontroller (7),
whereas sensors (3) and (4) have analog output signals,
which are converted to digital values via analog-to-digital
converter (8).
If microcontroller (7) in control unit (6) detects a
permanent error when the vehicle starts to move, this error
will be written into error memory (12). If the same error

recurs when the vehicle next starts to move, the count of
an error counter (18) allocated to this error in error
memory (12) is incremented in each case. The increment may-
have a value of 1, but a higher value such as 10 may also
be applied in each case.
If, when the vehicle once again starts to move at a later
time, it is found that the count of error counter (18) has
reached a predetermined value for a particular error, a
"Poor maintenance" special program takes over within
microcontroller (7) .
The "Poor maintenance" special program then disables
starting of the function being checked, such as an anti
brake-lock system (ABS), until expanded tests have been
performed and passed. Examples of such tests are a dynamic
check of all wheel-speed sensors during driving, a dynamic
test of the connected solenoid valves or other types of
exhaustive tests.
Other kinds of reactions may also be initiated by the "Poor
maintenance" special program, such as an intensive warning
or signal to the driver.
If the full scale of error counter (18) ranges from a count
of zero to a count of 250, for example, the "Poor
maintenance" special program may take over when the count
reaches 100.

After the vehicle has been driven for a predetermined time
without errors or for a predetermined distance without
errors, all or part of the count of error counter (18) is
automatically deleted once again.
In the case of partial deletion, the error counter is not
reset to zero directly, but instead the count is
decremented only by a predetermined fixed value, such as
50. The normal error tests explained initially, or in other
words simple tests for cable break, will be reactivated
only if the count ultimately reaches zero after the vehicle
has started to move several further times without errors.
Generally speaking, the inventive method comprises
inferring the state of maintenance of the vehicle from the
error count of the vehicle electronics. In the process, if
it is determined on the basis of an abnormally high error
count that the vehicle has demonstrably been poorly
maintained, then intensified tests are required. If these
intensified tests and expanded tests are not passed, then
for safety reasons the function being checked, such as an
anti brake-lock system (ABS), is completely disconnected.
The disconnection will be reported to the operator by a
warning light, so that from that time on he can adapt his
driving technique accordingly.
Although the inventive method has been explained with
reference to motor vehicle electronics, it can also be

applied to any other type of electronics provided with
error recognition and storage.

We Claim:
1. A method for treating errors in an electronic control unit of a vehicle, the
electronic control unit being programmed with an error-recognition program and
having an error memory for storage of permanent and sporadic errors, and an
error indicator, the method comprising the steps of:
writing into the error memory at least one error detected in the event of the
vehicle starting to move ;
in the event of the at least one error recurring, incrementing the count of
an error counter allocated to the at least one error in the error memory by
a preselected amount;
in the event of the vehicle starting to move on a subsequent occasion, the
count of the error counter reaching a prescribed value for the at least one
error, launching a poor maintenance program; and
using the poor maintenance program to prevent damage to the vehicle by
disabling the start of a vehicle function associated with the at least one
error until expanded tests have been performed and passed.
2. The method as claimed in claim 1, which involves the step of deleting at
least one of all and part of the count of the error counter in the event of the
vehicle having been driven for at least one of preselected time and a preselected
distance without errors.

3. The method as claimed in claim 2, which involves the step of
decrementing the count of the error counter by a preselected amount in the event
of a part of the count of the error counter being deleted.
4. The method as claimed in 1, which involves the step of enabling the start
of the disabled vehicle function in the event of the count of the error counter
reaching zero.

Documents:

00307-kolnp-2006-abstract.pdf

00307-kolnp-2006-claims.pdf

00307-kolnp-2006-description complete.pdf

00307-kolnp-2006-drawings.pdf

00307-kolnp-2006-form-1.pdf

00307-kolnp-2006-form-3.pdf

00307-kolnp-2006-form-5.pdf

00307-kolnp-2006-international publication.pdf

307-KOLNP-2006-ABSTRACT 1.1.pdf

307-KOLNP-2006-AMANDED CLAIMS.pdf

307-kolnp-2006-assignment.pdf

307-KOLNP-2006-CANCELLED PAGES.pdf

307-KOLNP-2006-CLAIMS 1.1.pdf

307-KOLNP-2006-CORRESPONDENCE 1.1.pdf

307-KOLNP-2006-CORRESPONDENCE 1.3.pdf

307-KOLNP-2006-CORRESPONDENCE-1.2.pdf

307-kolnp-2006-correspondence-1.4.pdf

307-KOLNP-2006-CORRESPONDENCE.pdf

307-KOLNP-2006-DESCRIPTION (COMPLETE) 1.1.pdf

307-KOLNP-2006-DRAWINGS 1.1.pdf

307-KOLNP-2006-EXAMINATION REPORT REPLY RECIEVED 1.1.PDF

307-kolnp-2006-examination report.pdf

307-KOLNP-2006-FORM 1.1.1.pdf

307-kolnp-2006-form 18.pdf

307-KOLNP-2006-FORM 2.pdf

307-KOLNP-2006-FORM 3.1.1.pdf

307-kolnp-2006-form 3.pdf

307-kolnp-2006-form 5.pdf

307-KOLNP-2006-FORM-27-1.1.pdf

307-KOLNP-2006-FORM-27.pdf

307-kolnp-2006-gpa.pdf

307-kolnp-2006-granted-abstract.pdf

307-kolnp-2006-granted-claims.pdf

307-kolnp-2006-granted-description (complete).pdf

307-kolnp-2006-granted-drawings.pdf

307-kolnp-2006-granted-form 1.pdf

307-kolnp-2006-granted-form 2.pdf

307-kolnp-2006-granted-specification.pdf

307-kolnp-2006-others-1.1.pdf

307-KOLNP-2006-OTHERS.pdf

307-KOLNP-2006-PETITION UNDER RULE 137.pdf

307-kolnp-2006-reply to examination report-1.1.pdf

307-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

abstract-00307-kolnp-2006.jpg


Patent Number 247508
Indian Patent Application Number 307/KOLNP/2006
PG Journal Number 15/2011
Publication Date 15-Apr-2011
Grant Date 13-Apr-2011
Date of Filing 13-Feb-2006
Name of Patentee WABCO GMBH & CO. OHG
Applicant Address AM LINDENER HAFEN 21, 30453 HANNOVER
Inventors:
# Inventor's Name Inventor's Address
1 EICKHOFF JURGEN KOTTE KAMP 8, 29664 WALSRODE
2 RUHNAU GERHARD ROTZBERG 11, 31535 NEUSTADT
3 PAPE KLAUS PETERMANNSTRASSE 14, 30455 HANNOVER
PCT International Classification Number G05B 23/02
PCT International Application Number PCT/EP2004/007857
PCT International Filing date 2004-07-15
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 103 44 460.2 2003-09-25 Germany