WO2000059742A1

WO2000059742A1 - Method and device for permitting a vehicle to continue driving after a drop in tire pressure and method for controlling a tire pressure monitoring system

Info

Publication number: WO2000059742A1
Application number: PCT/EP2000/002742
Authority: WO
Inventors: Martin Griesser
Original assignee: Continental Teves Ag & Co. Ohg
Priority date: 1999-04-03
Filing date: 2000-03-29
Publication date: 2000-10-12

Abstract

The invention relates to a method for permitting a vehicle to continue driving after a drop in tire pressure comprising the following steps: Detecting a value which varies according to the pressure of the tire; detecting at least one driving parameter for the continued driving of a vehicle according to the detected value, and outputting and/or adjusting the driving parameter. A device (1) for permitting the vehicle to continue driving after a drop in tire pressure comprises a value detection device (10) for detecting a value which varies according to the pressure of the tire, has a driving parameter detection device (11) which detects, according to the determined value, a driving parameter which permits the vehicle to continue driving, and comprises an output and/or control device (12, 13) for outputting the driving parameter to the driver and/or for controlling vehicle settings according to the determined driving parameter. The invention also relates to a method for controlling a tire pressure monitoring system which comprises the following steps: Monitoring the tire pressure of at least one tire mounted on a vehicle wheel; outputting a warning if a certain pressure loss is identified, and; controlling the tire pressure monitoring system according to the correction measure with which the loss in pressure had been corrected.

Description

Method and device for influencing the further travel of a vehicle after a tire pressure loss and method for controlling a tire pressure monitoring system

The invention relates to a method and a device for influencing the continued travel of a vehicle after a tire pressure loss and for controlling a tire pressure monitoring system according to the preambles of the independent claims.

In the event of a loss of pressure in a vehicle tire, it is necessary to inform the driver of this loss of pressure so that he can react to it in an appropriate manner. Previously known methods and devices for influencing the travel of a vehicle in the event of a tire pressure loss include the detection of the tire pressure loss using various methods and the qualitative display of the pressure loss. However, they do not give the driver any indication that and how the pressure loss has a safety effect. In addition, with this method, the driver is fundamentally able to continue the journey in an unchanged manner even with an extremely high pressure loss. From this, e.g. result from excessive speed, a safety hazard and an accident risk.

Methods for controlling tire pressure monitoring systems of the prior art include a “reset” after the warning has been issued and thereupon a corrective measure to remedy the cause of the pressure loss, in the sense of a complete deletion of the variables which have triggered the warning and the variables which have reacted to them were set. The system is then completely reset. This is necessary and useful if the defective wheel has been repaired permanently and a new Tire pressure monitoring system must be carried out in order to adapt the system to the changed operating state. In the case of provisional corrective measures, such as the use of tire repair sets (Tirefit systems), a complete reset does not take the circumstances into account as effectively as possible, for example because the success of the repair measure is not monitored or the system incorrectly believes that the normal state can be assumed. Known methods are unsuitable for controlling tire pressure monitoring systems in such cases.

The object of the invention is to reduce the risk of not adapting onward travel in the event of a loss of pressure in a tire.

Another object of the invention is to provide a method which enables control of a tire pressure control system which is well adapted to corrective measures.

These objects are achieved with the features of the independent claims, dependent claims are directed to preferred embodiments of the invention.

An influencing method is specified in which a value dependent on a tire pressure and a driving parameter are determined in accordance with the value. The driving parameter is brought to the driver's knowledge by outputting, alternatively or additionally, it can be set or regulated directly without the driver influencing, so that a safety-threatening onward journey is less likely. It can also be monitored and possibly lead to a warning. For example, the tire pressure can be determined using a method for monitoring tire pressure by measuring, comparing and evaluating the rotational speed of individual vehicle wheels, as disclosed by the applicant in PCT document WO 95/12498.

The driving parameter can be a (remaining) distance, a (remaining) time and / or a (maximum) speed. The driving parameter can then be output and / or set when the determined value has passed a limit value. Several driving parameters can be determined or output simultaneously. The output to the driver can be visual or acoustic. A general warning can also be issued. In addition to the driving parameters, information can be output to the driver on how he can remedy the defect in a suitable manner.

When determining the driving parameter, vehicle parameters such as Vehicle weight, the nature of the tires, damping setting, etc. are taken into account so that a driving parameter adapted to the respective vehicle and the situation can be determined.

The direct setting or adjustment of the driving parameters, e.g. a maximum driving speed, e.g. in the case of a high pressure loss, excluding the possibility of influence by the driver, via an engine control.

When carrying out the method for influencing the onward journey, vehicle components that are already available for other purposes, such as ABS systems, wheel sensors, position and navigation systems, and associated devices for data processing can be used, so that the driving can be influenced with only a small amount of vehicle components and ideally without additional hardware. If implemented by means of data processing, the method can refer to data from a data bus (eg CAN bus). A suitable operating system, such as OSEK, can control or distribute the individual processes.

In a method for controlling a tire pressure monitoring system, the tire pressure of the vehicle wheels is monitored and a warning is issued if a specific pressure loss is detected. After a repair measure, the system is controlled depending on the repair measure.

In the case of a provisional corrective measure, for example, the warning issued can be changed or reset and / or the size triggering the warning can be changed. This variable can be a calibration value for a wheel speed or signals from another component that detects the pressure loss. Another possibility is to change a status variable as a function of the corrective measure in such a way that reminder and / or monitoring and / or control measures are initiated. The system can be informed by input that a corrective action has taken place. The input signal can be implemented by the driver via the brake pedal or via menu items in the on-board computer or using two different buttons. The signals can also be supplied via a bus system, e.g. CAN bus. A time and / or speed window can be provided for driver input after the vehicle has been restarted. The monitoring of the tire pressure and the issuing of the warning for controlling the tire pressure monitoring system can take place as part of the method for influencing the onward journey. The control of the tire pressure monitoring system can include influencing the onward journey. Both methods can be implemented using the same hardware components.

Individual embodiments are described below with reference to the drawing. Show it:

1 shows a functional block diagram of a travel influencing device,

2 shows a functional block diagram of a driving parameter determination device,

3 shows a functional block diagram for explaining the method steps for influencing the onward journey, and

4 shows a functional block diagram for explaining the method for controlling the tire pressure monitoring system.

As shown in FIG. 1, the travel influencing device 1 comprises a value determination device 10, a travel parameter determination device 11, an output device 12, an adjustment device 13 and a monitoring device 14. The value determination device 10 contains, for example, a pressure detection device 101, a comparator 102 and a memory 103 The pressure detection device 101 can be a pressure sensor that detects the tire pressure directly, but it can also be, for example are wheel sensors that are used for pressure detection indirectly via the wheel speed. The comparator continuously or quasi-continuously (digital, clocked) checks whether the tire pressure of a vehicle tire falls below a certain limit value, which is stored in the memory 103. If this is the case, the value determination device 10 recognizes a pressure loss.

In this context, it is pointed out that the value determination device 10 and / or the pressure detection device 101 can be provided or work individually for the wheel. You can output individual results as different values or create one value together.

The value determination device 10 then outputs a pressure loss signal SD 10a to the driving parameter determination device 11. The driving parameter determination device 11 determines one or more driving parameters as a function of the signal SD 10a. In the present embodiment, it is possible for the driving parameter determination device 11 to transmit the determined driving parameter (s) to the output device 12 and / or the setting device 13 and / or the monitoring device 14 by signals Ila-c.

The driving parameters determined by the driving parameter determination device 11 can be a (remaining running) distance and / or (maximum) speed and / or (remaining running) time specification, but depending on the determined value, additional basic requests to the Driver, such as: "Strong pressure loss in the right front tire, please drive right immediately" by using the driving parameter determination direction 11 called and output to the driver via the output device 12. The adjusting device 13 can directly set a maximum permissible maximum speed for the onward journey, for example 80 km / h, without the driver being able to exceed it by actuating the accelerator pedal.

A driving parameter can be monitored by means of the monitoring device 14. If e.g. If the driving parameter is a maximum speed, the monitoring can issue an alarm if the actual speed is higher.

The value determination device 10 can continuously determine new pressure loss values, so that the driving parameter determination device 11 continuously determines new driving parameters in parallel. This opens up the possibility, in particular, of continuing the journey even in the event of a slight pressure loss until a safety hazard arises as a result of excessive pressure loss.

FIG. 2 shows an embodiment of the driving parameter determination device 11. It comprises a reset device

211 and a controller 212. The controller may include a microprocessor 212a, a random access memory (RAM) 212b and a read only memory (ROM) 212c. The pressure loss signal SD 10a is input from the value determination device 10 into the driving parameter determination device 11. The controller determines depending on this signal

212 the driving parameter signal Sp 21a.

The determined driving parameters can be saved in such a way that they are available again when restarting, for example in the event of a driver change. If as a driving parameter If a remaining distance is determined, it can be counted down based on the distances actually traveled. The counted down value can be saved when the vehicle is switched off, so that it is available in the counted down state when the vehicle is restarted. The same applies analogously if a remaining running time has been determined as a driving parameter.

The driving parameters can also be determined as a function of measured values, vehicle parameters or other status data fed in by a sensor 214. As a result, component settings of the vehicle that have an influence on the load on the defective tire, such as the setting of the damping system.

When determining the driving parameter, a calculation model (e.g. a formula) stored in memory 212c, for example, can be used to e.g. to calculate a residual running distance or time from the actual pressure and / or the pressure loss and / or the pressure gradient. The driver should be informed that, for example, he is likely to be able to drive 30 km with the defective tire before the tire pressure drops below a safety-critical limit. The model can describe the relationship between the pressure loss and various influencing factors, for example the driving speed, the vehicle weight and / or other factors which burden the tires.

The determined driving parameter can be continuously adapted to changed conditions: it can also be determined after it has been determined for the first time and, for example, can then be output for vehicle control if it reflects more unfavorable conditions than the previously used driving parameters (e.g. due to very strong pressure loss, the last remaining distance determined less than the previously determined or calculated remaining distance). The driving parameters to be output or adjusted can be entered in advance by the driver or in the workshop. There are often methods for detecting a loss of tire pressure, in which a suspicion arises based on certain values, but this suspicion does not yet lead to the issuance of a warning. A pressure loss is only recognized and a warning is only issued when the suspicion has been confirmed on the basis of further checks. If a driving parameter is counted down in such a system (remaining distance or remaining time), the counting down can take place from the suspicion.

A navigation system 213 can be controlled by the controller 212, for example to determine whether, for a given remaining distance of e.g. 20 km, a workshop can be started. The kilometer calculations necessary for the calculation of the controller 212 can be carried out from a position determination system or indirectly by integrating a speed signal which e.g. can come from the ABS sensors. The algorithm required for this can be implemented under the open and standardized software OSEK (open systems and their interfaces for the electronics in the motor vehicle) for ECUs. The corresponding data can preferably be read in by the controller 212 via a BUS system (e.g. CAN) from external components.

The driving parameter determination device 11 contains a reset device 211, which resets the control 212, in particular a status word or bit, if the air pressure rises to the original value as a result of the tire repair. In the event of a pressure increase, the driving parameter determination device 11 can request input by the driver through the input device 211 a contained in the reset device 211.

With the driving parameter determination device shown in FIG. 2, in particular the determination of the remaining running time, for example in the case in which there is only a slight pressure loss, can also take place without output of a driving parameter for information to the driver and e.g. stored for other or later uses.

Depending on how strong the pressure loss is, the method according to the invention can react flexibly by carrying out different method steps in succession or simultaneously. Possible process steps are illustrated in FIG. 3. The reaction options include the output of driving parameters to the driver (step 31), the monitoring of compliance with the driving parameters (step 32), the direct setting of the determined parameters for the onward journey (step 33) and the output of a warning to other road users (step 34 ). In this way, the increasing danger with increasing pressure loss can be taken into account.

Output devices for outputting the driving parameters can be, for example, an on-board computer with a display or a loudspeaker. If necessary, a navigation system can show the route to a nearest workshop on the display. The driving parameters on the vehicle can be set using an engine control that regulates the engine power so that the corresponding maximum speed can no longer be exceeded. A hazard warning system can be used to warn other road users.

The method for controlling the tire pressure monitoring system is explained below with reference to FIG. 4. 4 illustrates the course of the method and in particular the various measures that can be carried out as part of the control. In step 40, the tire pressure of at least one vehicle wheel is monitored and a warning is issued if a certain pressure loss occurs. Thereupon, in step 41, the driver usually initiates a corrective action, for example fitting a spare wheel, using a tire repair kit or the final repair in the workshop, and an input with which the system provides qualitative and / or quantitative information about the corrective action and / or the control measure to be carried out. The entry can e.g. inform the system qualitatively that either a provisional or a final repair has been made. The input can be saved as a status variable or can influence a status variable. In step 42, one or more method steps (421-424) are then carried out for the future control of the tire pressure monitoring system. For example, in step 421, if the correction is only provisional (e.g. tire repair kit), the warning issued can be deleted.

In step 422, a status variable can be set to a specific value in order to initiate reminder, monitoring and / or control measures, such as have been described, for example, with reference to FIG. 1 or 3. As a result, the driver can be informed, for example, that the only temporarily repaired tire must not be fully loaded, so that, for example, a certain maximum speed must not be exceeded. This can then be monitored accordingly.

In step 423, calibration values for wheel radii and / or tire pressures can be changed in response to the input. As a rule, the tire radius after the repair measure will no longer have the previous value. This can e.g. when using a spare wheel with a smaller wheel radius and / or tire pressure that is not suitable for continuous operation. The radius may have increased due to inflation. In the event of a final corrective action by e.g. When a new tire is fitted, the system can set a standard value for the corresponding wheel radius or its correction factor in step 423 and then recalibrate it. If a spare wheel that is not suitable for continuous operation is used, the fault detection threshold values can also be modified in step 424 in order to implement an adapted pressure loss monitoring. General control parameters, e.g. Threshold values or setpoints for which brake and / or motor control are modified.

The input signal can be entered via menu items in the on-board computer or one, two or more buttons, but also via the brake pedal. Preferably, a certain number of brake light switch operations are counted in a time window and, depending on this, the corresponding measure for the control is initiated. A certain time and / or speed window can be permitted for the input after the vehicle is restarted. The method for controlling the tire pressure monitoring system can be combined with the method for influencing the onward journey. This can be done in such a way that a certain value of the status variable (step 422) triggers the parameter determination device 11 (FIG. 1), so that, in the case of a merely provisional corrective measure, a suitable driving parameter for influencing the onward journey is determined and then used as described above . For example, a maximum speed of 120 km / h can be set using a tire repair kit.

Both methods can have the same hardware components as, e.g. Output, input and data processing facilities use. The calculations required in the context of both methods can be carried out in the controller 212 in FIG. 2. The input device for carrying out the control of the tire pressure monitoring system can be the input device 211a of the reset device 211 of the parameter determination device 11 of FIG. 2.

Claims

Patent claims

1. Method for influencing the continued journey of a vehicle after a loss of tire pressure, with which

Step

Determining a value that depends on a tire pressure,

characterized by the further steps

Determining a driving parameter for the vehicle's continued journey depending on the determined value, and

Outputting and/or monitoring and/or setting the driving parameter.

2. The method according to claim 1, characterized in that the driving parameter is also determined as a function of vehicle characteristics.

3. The method according to claim 1 or 2, characterized in that the driving parameter indicates a route and / or a time and / or a speed.

4. The method according to claim 3, characterized in that a remaining running time of the tires and / or a permissible or recommended maximum speed of the vehicle are specified as driving parameters.

5. Method according to one of claims 1 to 4, characterized in that the driving parameter is output or set or monitored when the determined value passes a limit value.

6. Method according to one of claims 1 to 5, characterized in that the driving parameter and/or a warning to the driver and/or instructions for remedying the defect are output optically and/or acoustically.

7. Method according to one of claims 1 to 6, characterized in that an acoustic and/or visual warning is issued to other road users.

8. The method according to claim 7, characterized in that, depending on the driving parameters, the output, setting and warning of other road users takes place independently of one another at the same time and / or in the specified order.

9. The method according to one of claims 1 to 8, characterized in that the driving parameter is adjusted without the driver having any influence.

10. The method according to one of claims 1 to 9, characterized in that the determined value is a tire pressure.

11. Influencing device for influencing the further journey of a vehicle, in particular for carrying out the method according to one of the preceding claims, with a value determination device for repeatedly determining a value that depends on a tire pressure,

marked by

- a driving parameter determination device for determining at least one driving parameter for the vehicle vehicle travel depending on the determined value, and

- an output and/or a monitoring and/or an adjustment device for outputting the driving parameter to the driver or for setting the driving parameter on the vehicle.

12. Method for controlling a tire pressure monitoring system, with the steps

Monitoring the tire pressure of at least one vehicle wheel, and

Issue an alert when a specific pressure loss is detected,

characterized in that

After a corrective measure after the pressure loss, the control is carried out depending on the measure with which the pressure loss was corrected.

13. The method according to claim 12, characterized in that the control comprises one or more of the following measures:

warning measures,

Setting a status variable,

Calibration measures for wheel radii and/or tire pressures, and Setting error detection thresholds.

14. The method according to claim 12 or 13, characterized in that a warning is changed, in particular reset, after a provisional corrective measure.

15. The method according to any one of claims 12 to 14, characterized in that after a provisional corrective measure, a variable that triggers the warning is changed.

16. The method according to claim 15, characterized in that a calibration value for a wheel speed is changed.

17. The method according to one of claims 12 to 16, characterized in that after a provisional corrective measure, a status variable is set to a value that triggers reminder or monitoring or control measures.

18. The method according to any one of claims 12 to 17, characterized in that after a final corrective measure, a status variable is set to a neutral value and / or a warning is reset.

19. The method according to any one of claims 12 to 18, characterized in that the implementation of a corrective measure and / or the type of corrective measure is entered by the driver.

20. The method according to claim 19, characterized in that the driver input takes place via the brake pedal.

21. The method according to claim 20, characterized in that the driver input is permitted for a time and/or speed window after the vehicle has been restarted.

22. The method according to one of claims 12 to 21, characterized in that after a provisional corrective measure, a status variable is set to a value which causes the measures of the characterizing part of claim 1.

23. The method according to one of claims 12 to 22, characterized in that monitoring the tire pressure and issuing a warning takes place as part of the influencing method according to one of claims 1 to 8, the determined value being a tire pressure.

24. The method according to claim 23 and claim 14, characterized in that the changed warning was issued according to claim 5.

25. The method according to one or more of the preceding claims, characterized in that after the target tire pressure has been reached again, the system has been reset and/or the tires have been restored to their proper condition, a query is made as to whether new tires have been fitted and/or whether the remaining running time is again was reset to the original value or whether the tire pressure should be adjusted and the remaining running time should not be reset, but the display should be removed.

6. Device for controlling a tire pressure monitoring system, with

a monitoring device (40) for monitoring the tire pressure of at least one vehicle wheel, and

an output device (421) for issuing a warning when a certain pressure loss is detected,

marked by

a control device (42), which, after a corrective measure after the pressure loss, carries out the control depending on the measure with which the pressure loss was corrected.

27. The device according to claim 26, characterized by an input device (41) for entering information regarding the corrective measure.

28. Device according to claim 27, characterized in that the input device comprises a pedal of the vehicle.

29. Device according to one of claims 26 to 28, characterized by a status register (422) for storing a status variable according to which device components (421, 423, 424) are operated.