Method for Reproducing an Error That Occurs During the Driving Operation of a Vehicle

Abstract

A method for reproducing an error that occurs during the driving operation of a vehicle is provided. The vehicle is fixed in position in order to prevent movement relative to a reference surface on which the vehicle is located. A speed profile provided by an engine analyzer is read into a control device of the vehicle and is converted by the control device into a load profile. Subsequently, with the brake activated, the control device in the vehicle automatically runs through the speed profile, the device having converted the speed profile into at least one control parameter of the engine and/or the transmission over time in order to simulate the load profile, when the vehicle is under load as a result of the activation of the brake.

Claims

1.-13. (canceled)

14. A method for reproducing a fault that occurs during a driving operation of a vehicle, the method comprising: fixing the vehicle in position in order to prevent a movement relative to a reference surface on which the vehicle is located; reading a speed profile, which simulates a driving situation in which the fault has occurred during the driving operation, by an engine tester into a control device of the vehicle; and providing automated traveling along the speed profile by the control device, which converts the speed profile into at least one control parameter of at least one of an engine or a transmission over time, in the vehicle when the vehicle is loaded by activation of a brake.

15. The method according to claim 14, wherein the fixing the vehicle in position comprises automated, and constant activation of the brake of the vehicle brought about by the control device.

16. The method according to claim 15, wherein the fixing the vehicle in position further comprises a maximum activation of the brake of the vehicle brought about by the control device.

17. The method according to claim 14, wherein the fixing the vehicle in position comprises arranging the vehicle such that wheels of the vehicle are freely rotatable.

18. The method according to claim 14, wherein the fixing the vehicle in position comprises mechanical fixing in position.

19. The method according to claim 14, wherein: a sensor senses a temperature signal which represents at least one of a transmission temperature or a clutch temperature, and transfers the temperature signal to the control device for comparison with a specified threshold value temperature, and the traveling along the speed profile is aborted if the temperature signal is higher than the specified threshold value temperature.

20. The method according to claim 14, wherein the at least one control parameter of the engine comprises at least one of an engine speed or a load requested by the engine.

21. The method according to claim 14, wherein the at least one control parameter of the transmission comprises a drive position.

22. The method according to claim 14, wherein: a driver assistance system control device monitors whether a relative movement is detected during a test, and when the relative movement is detected by the driver assistance system control device, a control signal for activating a parking brake is output.

23. The method according to claim 14, wherein a speed engine temperature profile is processed as the speed profile.

24. The method according to claim 14, wherein providing the automated traveling along the speed profile is carried out by a driver assistance system control device as the control device.

25. The method according to claim 14, wherein providing the automated traveling along the speed profile is carried out by an engine control device as the control device.

26. A computer program product comprising a non-transitory computer readable medium having stored thereon program code which, when executed on a processor, a microcontroller, or a programmable hardware component, carries out a method for reproducing a fault that occurs during a driving operation of a vehicle, the method comprising: fixing the vehicle in position in order to prevent a movement relative to a reference surface on which the vehicle is located; reading a speed profile, which simulates a driving situation in which the fault has occurred during the driving operation, by an engine tester into a control device of the vehicle; and providing automated traveling along the speed profile by the control device, which converts the speed profile into at least one control parameter of at least one of an engine or a transmission over time, in the vehicle when the vehicle is loaded by activation of a brake.

27. A control device of a vehicle which is configured to execute a method for reproducing a fault that occurs during a driving operation of the vehicle, the method comprising: fixing the vehicle in position in order to prevent a movement relative to a reference surface on which the vehicle is located; reading a speed profile, which simulates a driving situation in which the fault has occurred during the driving operation, by an engine tester into a control device of the vehicle; and providing automated traveling along the speed profile by the control device, which converts the speed profile into at least one control parameter of at least one of an engine or a transmission over time, in the vehicle when the vehicle is loaded by activation of a brake.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 shows a schematic illustration of a program flow diagram of an embodiment of a method according to the invention.

[0023] FIG. 2 shows a schematic illustration of the components of a vehicle and of an engine tester which are involved in the execution of an embodiment of the method according to the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0024] The reproduction of a fault that occurs during the driving operation of a vehicle 10 is made possible using the sequence shown in FIG. 1 for an embodiment of the method according to the invention. The vehicle 10, which is illustrated schematically in FIG. 2, comprises an internal combustion engine and/or an electric motor as a drive source/drive sources. The vehicle 10 comprises a control device 12, the engine 14, which has already been mentioned as a drive source, and a brake 16 which acts on wheels 18, 20. The control device 12 is configured to be connected to a vehicle-external engine tester 30, in order to exchange this data therewith.

[0025] In order to carry out the method according to an embodiment of the invention, according to step 51 the vehicle 10 is fixed in position in a test environment, for example a workshop of the vehicle manufacturer. The fixing of the vehicle 10 in position can be carried out using the brake 16 which acts on the wheels 18, 20. The brake 16 is firstly activated to a maximum extent, in particular in an automated fashion. As a result, within the scope of the method described above the residual braking effect of the brake 16 can be sensed. This makes it possible to determine whether the brake 16 can retain the maximum requested torque. The activation of the brake 16 is brought about, in particular, by the control device 12, and preferably in such a way that the brakes exert a maximum braking force on the wheels or the braking means (brake disk or drum) connected to the wheels 18, 20. In addition, the vehicle can be optionally fixed in position externally. For example, the vehicle can be tied down by cables and/or rods at its trailer hitch (not shown) and/or at a towing hook (not shown) and/or the wheels 16, 18. The vehicle can also be fixed in position in such a way that the vehicle 10 is arranged with respect to a reference surface 5 in such a way that its wheels are freely rotatable. For this purpose, the vehicle 10 can be arranged e.g. on a lifting platform.

[0026] As becomes clear from the following description, the method is carried out with the brakes 16 closed, that is to say activated, so that the wheels 18, 20 do not rotate. The arrangement of the vehicle 10 such that the wheels cannot freely rotate occurs for safety reasons in order to prevent undesired relative movement with respect to the reference surface 5, which would possibly be dangerous for people located in the surroundings. In addition, this is intended to avoid damage to the vehicle 10 and/or the elements in the surroundings.

[0027] According to step S2, a speed profile which is provided by the engine tester 30 is read in. The speed profile, which can be generated manually and/or automatically, simulates as well as possible, in particular, the driving situation in which a fault which was reported by the user of the vehicle has occurred during the driving operation. The reading in is carried out by the engine tester 30 into the control device 12 of the vehicle.

[0028] Since a large number of phenomena occur only at specific engine temperatures, such as e.g. an internal combustion engine which is running unsteadily at a cold start or a lack of engine power when the engine is warm or juddering when warming up, it is expedient to specify the input which is provided by the engine tester 30 not only as a speed profile but optionally also as a speed engine temperature profile. The “setpoint temperature” of such a profile can then be applied for the reproduction with the customary possibilities of the vehicle-internal cooling circuits.

[0029] The sequence of the steps 51 and S2 can also be carried out herein in the reverse order, that is to say the step S2 can be carried out before the execution of the step 51.

[0030] In a subsequent step S3, an automated execution of the speed profile occurs under the control of the control device 12. For this purpose, the control device 12 converts the speed profile into one or more control parameters of the engine 14 and/or of a transmission (not illustrated in more detail) over time, in order to generate a load profile. The load profile comprises a successive increase in load (i.e. torque which is applied to the wheels 18, 20) and engine speed until the fault situation reported by the user is reached or exceeded. The conversion of the speed profile into the control parameter or parameters of the engine and/or of the transmission is carried out here in an automated fashion by the control device 12, which inherently has such conversion functionalities.

[0031] Such a control device 12 can be, for example, an engine control device or else driver assistance control device, such as for example the control device of an automatic parking function (known as a parking pilot or remote control parking, RCP) or an adaptive cruise control system which generate corresponding load parameters and rotational speed parameters on the basis of a speed specification. A driver assistance control device which implements an automatic parking function can, furthermore, also be used to activate the brake 16, in order to prevent rotation of the wheels 18, 20.

[0032] Since the application of a load to the engine 14 and the transfer of said load to the wheels 18, 20 via the transmission (not illustrated) results in slip in the clutch (not illustrated), said clutch warms up. The thermal loading can be carried away only to an insufficient degree over a relatively long time since the stationary vehicle does not have a flow of air around it. In order to avoid thermal damage, a sensor (not illustrated) senses a temperature signal which represents the transmission temperature and/or clutch temperature and transfers it to the control device 12 for comparison with a specified threshold value temperature. If it is detected during the execution of the speed profile that the determined temperature signal is higher than the specified threshold value temperature, the execution of the speed profile is automatically aborted. The thermally loaded component can then, if expedient, be changed, for example, into a “cooling cycle” in order to reduce the thermal loading during operation. As described, the sensor or the temperature calculation model can sense, in particular, the temperature of the oil of the transmission and/or of the clutch. During the conversion of the speed profile into the load profile, the control of torque, rotational speed and time can be implemented in such a way that a maximum tolerable input of energy into the transmission and/or the clutch is not exceeded.

[0033] The load which occurs in practice during the execution of the speed profile is simulated by the brake 16, wherein the brake 16 is, as described above, constant and, in particular, depressed to a maximum degree.

[0034] The method according to an embodiment of the invention can be implemented, in particular, in such vehicles which have an automatic transmission, since in said vehicles the corresponding gear speeds of the transmission can also be changed automatically by the control device in order to simulate the speed profile. In this context, transmission and clutch protection functions which are present for protecting against thermal overheating of the torque converter can be used so that in the case of an increased input of heat a prompt decrease in the loading can be implemented.

[0035] The method according to an embodiment of the invention permits a customer complaint which occurs during the driving operation of the customer to be simulated. This is made possible by converting a relevant speed profile into a load profile. As a result, repair measures can be validated under load. Workshops can dispense with the execution of a test run. Faulty repairs or repairs based on faulty information can be avoided.

LIST OF REFERENCE NUMBERS

[0036] 5 Reference surface [0037] 10 Vehicle [0038] 12 Control device [0039] 14 Engine [0040] 16 Brake [0041] 18, 20 Wheels [0042] 30 Engine tester