DE4302925A1 - Method and device for the reporting of faults in vehicles - Google Patents

Abstract

A method and a device for the reporting of faults in vehicles is proposed in which, when a fault occurs, the speed of the vehicle is restricted. The extent of the speed restriction may be selected as a function of the seriousness of the fault and the length of time which has elapsed since the fault occurred. <IMAGE>

Description

State of the art

The invention relates to a method and an apparatus for mistake Registration in vehicles according to the independent patent claims.

Such a method or device is made of egg ner numerous publications known. For example, in DE-OS 35 10 321 (US Pat. No. 4,960,087) proposed an error the technology of a vehicle, possibly alongside or instead of one Warning lamp to report to the driver that an operating condition abnormally changed outside of driving. The goes Suggestion that if there is a fault, the idling speed to modulate the motor. This measure makes an occurring An error that can also exist if a warning lamp fails, namely the Driver reported, the driver is outside of the idle state however, in spite of the present fault condition over the full lei engine performance.

It was therefore proposed in DE-OS 37 31 109 (GB-A 2 209 854) in the event of an error condition, a power limitation of the Motor. This is achieved in that the driver familiar characteristics of the performance specification modified in this way is that when the accelerator pedal is pressed an idle path without An  speak of the engine z. B. at the beginning of the operation and / or at the end the actuation distance of the accelerator pedal. Aim of the presented The procedure is to limit the power of the engine to a certain level sen percentage rate, e.g. B. 30% of the maximum power of the motor. One mo However, gate power limitation allows in certain operating states (e.g. in low gears) high vehicle speeds, so that z. B. Error conditions in an electronic brake system, the due to little or no impairment of driving behavior are marked, the driver in a sufficient manner det, the resulting impairment of operational reliability vehicle is not always taken into account.

It is therefore an object of the invention, a method and a device indicate the condition for reporting fault conditions in a vehicle, where both a sufficient notification of the error to the driver achieved as well as ensuring the operational safety of the vehicle becomes.

This is achieved in that a limit is set when an error occurs the driving speed of the vehicle is made.

From DE-OS 32 44 250 it is known to monitor and warning lamps to recognize their failure.

From US Pat. No. 4,493,210 there are measures for fault detection in the brake systems known.

Advantages of the invention

The procedure according to the invention has the advantage that an error stood in the area of the vehicle, especially in systems where an error condition does not immediately lead to an impairment of driving operations, reported to the driver in a clear manner and operational safety is nevertheless guaranteed.  

Especially in the case of errors or defects in ABS / ASR systems or electrical braking systems without mechanical redundancy leads to a fault not necessarily to impair the driving of the Vehicle like a mistake in the field of engine control itself, he however, leads to a crisis for the operational safety of the vehicle table deterioration in system behavior. In particular, can A major loss due to faults in electrical braking systems the braking ability of the vehicle. An error message However, the driver often ignores the warning lamp, likewise like a failure of the warning lamp the driver from the fault condition of the Systems experiences nothing. By intervention in the invention Vehicle speed will change this to a lower speed limited, which on the one hand represents an error message, the operating security guaranteed and reaching a workshop or egg ner parking space allowed.

In particular, the limitation of the speed becomes a part the risk that there is a change in braking performance, com pens because the vehicle's speed is no longer increased can be reached. At speeds below the limit However, the driver has the full engine power at speed Available so that limited availability is guaranteed is.

It is particularly advantageous if the speed limit with increasing vehicle service life during which the Error condition exists, is reduced.

It is also particularly advantageous to decrease the speed limit depending on the severity of the error that occurs.  

A particularly advantageous application also exists in connection with the error message when a warm lamp fails or together hang with prescribed inspection or other investigation periods of time caused by the increasing speed limit is displayed.

Further advantages result from the description of execution examples and from the dependent claims.

drawing

The invention is explained below with reference to the embodiments presented in the drawing Darge. Here, FIG. 1 shows an overview block diagram of a control system for a vehicle using the example of an electronic braking system and an engine control. In Fig. 2, the procedure according to the invention is outlined using a flowchart.

Description of exemplary embodiments

Fig. 1 is an overview block diagram showing a control system for a vehicle. The control unit 10 shown by way of example consists of an engine control 12 and a control unit 14 for electronically influencing the brakes. The control unit 12 can be, for example, an electronic accelerator pedal system or a control unit for influencing the air supply, fuel supply and / or ignition or an electronic diesel control. In a preferred exemplary embodiment, the control unit 14 can be an ABS control unit or an electronic brake, in which, depending on the brake pedal actuation, the extent of the brake intervention is preferably determined without mechanical redundancy. The control unit 12 is connected via line 16 to at least one actuating device 18 influencing the performance of the engine, while the control unit 14 is connected via a line 20 to actuating devices 22 for influencing the brakes of the vehicle. Furthermore, as shown in FIG. 1 of importance as, the control unit 14 a Fehlerer identification device 24, preferably as part of a computer, which detects error states in the control unit 14 or the system peripherals. This error detection device is connected via a line 26 to a warning lamp 28 , a line 30 possibly leading back from the line 26 to the error detection device 24 for failure detection of the warning lamp 28 . The control units 12 and 14 are connected via a line system 32 for mutual data and information exchange, the line system 32 also leading to a symbolically represented input unit 34 which combines the input lines. Therefore, on the input unit 34, the input lines 36-38 are guided, which connect the input unit 34 with the measuring devices 40-42 for detecting operating variables of the engine and / or vehicle.

In addition to the elements shown, the control system 10 can of course have the elements known from the prior art, for example for controlling fuel metering and ignition timing, for controlling an automatic transmission and for carrying out further control tasks present in conventional vehicles.

The engine control unit 12 adjusts the control device for influencing the engine power 18 in the sense of the driver's request. For this purpose, the position of a control element which can be actuated by the driver is detected by one of the measuring devices 40-42 and transmitted to the control unit 12 . This forms a target position for the actuating device 18 in the case of control of the air supply and sets this for example in the context of a position control. In special operating conditions, such as in the idling state, the actuating device 18 is set to a predetermined target speed in the sense of regulating the engine speed.

In the exemplary embodiment of an ABS control unit, the control unit 14 receives wheel speed signals from the measuring devices 40-42 , the corresponding brake pressure being reduced when the brake is actuated in the event of a wheel tending to lock and thus preventing the wheel from locking. In the case of a spinning drive wheel, the speed of this wheel is limited in such a way that a predetermined slip occurs. An intervention in the engine power can also be provided. In the exemplary embodiment of an electric brake, one of the measuring devices 40-42 derives the brake driver's request from the position of a control element which can be actuated by the driver, and the brake pressures in the brakes are produced electrically on the basis of the determined driver's request and, if appropriate, further operating variables such as engine speed, driving speed, gear position , etc. set.

The error detection unit 24 checks the functionality of the control unit 14 as part of the methods known from the prior art. The error detection unit 24 is able to check the functioning of the control unit 14 as well as the correct functioning of the measuring devices 40-42 and actuators 18 and 22 . The fault detection unit 24 divides them into different groups when a fault is detected. A serious error is, for example, the failure of one of the two computers in the control unit 14 which is generally present, while a comparatively minor error is the failure of the warning lamp 28 , which can also be checked for the methods known from the prior art. Furthermore, in a preferred embodiment, the error detection unit 24 is designed such that, after an error has been detected, a counter is activated which determines the operating time of the vehicle after the error has been detected.

In a preferred embodiment, in addition to that shown Brake system an additional brake, e.g. B. a retarder.  

Via the connecting line 32 , the information acquired by the error detection unit 24 about the presence of an error, its severity and the operating time that has elapsed since the error was detected are transmitted to the control unit 12 . This processes the information and determines a limit value for the driving speed, which is selected as a function of the severity of the error and decreases in amount with increasing operating time since the error occurred. It can be provided, for example, that in the event of minor errors, the speed of the vehicle for cars is limited to 70 km / h, for trucks to 50 km / h, while for serious errors, the limit for cars is 30 and for trucks to 20 km / h takes place. Furthermore, the vehicle speed limit can be reduced with increasing operating time since the error occurred. Here, for example, an operating time in the hour range is envisaged, for example in the case of cars to reduce the driving speed limitation from 70 km / h to 30 km / h.

The program running in control unit 12 to carry out the procedure according to the invention is shown in FIG. 2.

After the start of the program part at predetermined times, a check is made in a first step 100, for example on the basis of a mark emitted by the control unit 14 , to determine whether there is an error state. If this is not the case, the actuating device 18 is set in accordance with step 102 in accordance with the determined driver's request or, in the case of the idling state, in accordance with the idling target speed. Then the program part is repeated at the given time.

If an error condition is detected in step 100, then in step 104 the vehicle speed Vist, a measure of the severity of the error S and the operating time Z that has elapsed since the error occurred, and in the subsequent step 106 the limit vehicle speed V limit based on the severity of the error S and the time after the occurrence of the error Z are determined. It is then checked in query step 108 whether the measured actual speed is greater than the predetermined limit speed. If this is not the case, the process continues with step 102 and the actuating device 18 is started on the basis of the driver's request. If the driving speed is greater than the limit speed, the speed is reduced in accordance with step 110, taking back the power of the motor by returning the actuating device 18 , the program part is ended and repeated at the given time.

In a preferred exemplary embodiment, the speed is reduced by returning the actuating device 18 by a predetermined amount. When the actuator 18 is completely closed, in a preferred embodiment, the additional brake, the retarder, is engaged if the driving speed continues to exceed the limit speed. It is also possible to think of reducing the ignition or switching off the fuel supply.

Besides limiting the speed based on the speed speed signal can limit the speed on the Ba sis of the engine speed signal taking into account the over drive train. This is particularly advantageous as a supplement to the speed limit based on the vehicle speed signal, in case that the vehicle speed signal to cancel the speed limitation is manipulated.

Claims (10)

1. Procedure for error messages in vehicles,

• - With a first control unit ( 12 ) for influencing the engine power of the vehicle,
• - with an error detection unit ( 24 ) for detecting error conditions,
• - The control unit ( 12 ) is equipped in such a way that it intervenes in the engine performance when an error occurs.
  characterized in that
• - The control unit ( 12 ) is equipped such that when the error occurs, the speed of the vehicle is limited.

2. The method according to claim 1, characterized in that the error detection unit ( 24 ) detects errors in the region of a second control unit ( 14 ) which engages in the actuation of the brakes of the vehicle. 3. The method according to any one of the preceding claims, characterized in that the error detection unit ( 24 ) checks the operation of the control unit ( 14 ), the operation of the associated measuring devices and / or actuating devices and / or the operability of warning lamps and when selected or Inoperability of the corresponding elements generates an error message, before the recognized errors are grouped in terms of their severity and a time measurement starts, which represents the operating time of the vehicle after the error occurred. 4. The method according to any one of the preceding claims, characterized ge indicates that the vehicle speed limit depends on the Severity of the error and / or depending on the operating time of the Vehicle has been specified since the error occurred. 5. The method according to any one of the preceding claims, characterized ge indicates that the vehicle speed limit is based on of the driving speed signal. 6. The method according to any one of the preceding claims, characterized ge indicates that the vehicle speed limit is based on of the engine speed signal, preferably taking into account the Transmission ratios of the drive train. 7. Device for signaling errors in vehicles,

• - With a first control unit ( 12 ) for influencing the Motorlei stung,
• - With an error detection unit ( 24 ) for detecting error conditions,
• - The control unit ( 12 ) has a power-reducing effect on the motor,
  characterized in that
• - The control unit ( 12 ) limits the speed of the vehicle when a fault is detected.

8. The device according to claim 7, characterized in that the ste control unit ( 12 ) represents an electronic engine power control or an electronic diesel control. 9. Apparatus according to claim 7 or 8, characterized in that the error detection unit ( 24 ) detects errors in the region of a second control unit ( 14 ) which acts on the brake actuation of the vehicle and is an ABS control unit or an electric brake system. 10. Device according to one of claims 7-9, characterized in that the control unit ( 12 ) is designed such that the limit value of the driving speed depending on the severity of the error and / or on the operating time of the vehicle since the error occurred is.