WO2016206793A1

WO2016206793A1 - A method for operating a driver assistance system of a motor vehicle

Info

Publication number: WO2016206793A1
Application number: PCT/EP2016/001035
Authority: WO
Inventors: Carsten KAUSCH; Michael Schoenberger
Original assignee: Audi AG
Current assignee: Audi AG
Priority date: 2015-06-24
Filing date: 2016-06-17
Publication date: 2016-12-29
Anticipated expiration: 2017-12-24
Also published as: CN106274896A

Abstract

Capturing at least one parameter for at least one individual tire (20) of the motor vehicle (10) which characterizes the driving stability of the motor vehicle (10); Controlling of a display device of the driver assistance system (12) in dependency on the at least one captured parameter, whereby the at least one parameter is captured per tire (10) for at least two individual tires (10) of the motor vehicle (10), whereby for each of the at least two individual tires (20) a corresponding section (26 to 32) of the display device (18) is controlled in dependency on the respective captured parameter. Furthermore the invention relates a driver assistance system (12) for a motor vehicle (10) designed to perform such a method.

Description

A Method for Operating a Driver Assistance System of a Motor Vehicle

DESCRIPTION: The invention relates to a method for operating a driver assistance system of a motor vehicle according to the preamble of patent claim 1. Furthermore, the invention relates to a driver assistance system.

A method for operating a driver assistance system of a motor vehicle can comprise capturing at least one parameter for at least one individual tire of the motor vehicle which is significant for a driving stability of the motor vehicle. Furthermore, the method can comprise controlling a display device of the driver assistance system in dependency on the at least one captured parameter.

For example, a driver assistance system such as an electronic stability program (ESP) can comprise those steps. ESP can also be referred to as electronic stability control (ESC), or dynamic stability control (DSC). The captured parameters are compared to threshold values. If one captured parameter of an individual tire surpasses a certain threshold, the ESP for example tries to increase driving stability by braking one individual tire. This can be signaled to the driver of the motor vehicle by activating an indicator lamp. Although the ESP increases driving stability of the motor vehicle and thus allows for better control of the motor vehicle by the driver, the ESP does not help the driver to control the motor vehicle in such a way that he can avoid maneuvers that require an intervention by the ESP.

Document US 7 769 499 B2 discloses a method for generating a ranking of driver performances based on a plurality of collected metrics. The metrics that are collected can include, for example, idle-time, acceleration and deceleration, times that a speed limit is exceeded and other metrics of interest for evaluating driver performance. The disclosed method does not allow the driver to increase his driving performance while driving the motor vehicle. Also the disclosed method does not support the driver in better controlling the motor vehicle.

Document DE 10 2009 023 867 A1 discloses a method for indicating to a vehicle driver his performance in comparison to a preset driving modus. This allows the driver to adjust his driving in order to better match this driving mode. For example, the driving mode can be performance orientated or economically orientated. Thus, the method allows the driver to increase his driving efficiency with regard to speed or fuel consumption. The method does not allow the driver to improve his control over the vehicle for the purpose of achieving a better driving stability.

Document DE 10 2006 049 727 A1 discloses a method to set various driving characteristics of a vehicle. For example, the characteristics of an accelera- tion paddle can be changed or the distribution of a motor torque on different vehicle axis and wheels can be changed. Another example is to change the braking characteristics of an individual tire. This allows changing the horizontal and/or vertical dynamics of the vehicle. This method can be used to set the vehicle in a special down hill or traction mode and to increase driving stability. The document does not disclose a method for operating a driver assistance system and how such a system can improve the control of the driver over motor vehicle.

It is an object of the present invention to provide a method for operating a driver assistance system of a motor vehicle and a driver assistance system itself that allow a driver to control the motor vehicle especially well with regard to its driving stability.

This object is solved by a method having the features of patent claim 1. Fur- thermore, this object is solved by a driver assistance system having the features of patent claim 10. Advantageous embodiments with expedient developments of the invention are indicated in the other patent claims.

A first aspect of the invention concerns a method for operating a driver assis- tance system of a motor vehicle that comprises capturing at least one parameter for at least one individual tire of the motor vehicle which is significant for a driving stability of the motor vehicle. Furthermore, the method comprises controlling a display device of the driver assistance system in dependency on the at least one captured parameter. According to the invention, the at least one parameter is captured per tire for at least two individual tires of the motor vehicle, whereby for each of the at least two individual tires a corresponding section of the display device is con- trolled in dependency on the respective captured parameter. This means that a different section of the display device is associated to each tire for which at least one parameter significant for the driving stability is captured. This allows the driver to assess the driving stability of the motor vehicle especially well, thus especially improving his control over the motor vehicle and its driv- ing stability. The driver gets information for each specific tire regarding their state in relation to the driving stability of the motor vehicle. Thus the driver can also determine which specific driving maneuvers can improve the driving stability especially well in a certain driving situation. In addition or alternatively the driver can also determine which driving maneuvers are still allowable without endangering the driving stability in a certain situation. For example, the driver can avoid, a driving maneuver that would require usually trigger an intervention by an ESP.

For example, if the parameter is captured for both the left and the right front tire, the driver can get a visual feedback on the influence of his steering commands on the driving stability. If, for example, the parameter is captured for the driven tires, the driver can get especially precise information on the influence of his acceleration and/or deceleration commands on the vehicle driving stability.

The method can also help the driver to keep control of the motor vehicle in off-road driving conditions. For example, when driving down a hill, the driver assistance system can indicate to the driver by means of the display device if or which tire of the motor vehicle might slip and/or in which direction the motor vehicle might break out. Also, the method can improve a driving performance by allowing the driver to operate the motor vehicle as close as possible to an allowable minimal driving stability. For example, this can allow a driver to reduce his lap time on a race track. Due to each section being controlled in dependency on the parameters corresponding to an individual tire, the driver can experience visually the influence of a four-wheel drive on the driving stability, especially in comparison to a standard drive. Also the effects of other driver assistance systems and/or features of the drive train can be illustrated directly. The parameter for an individual tire can be captured by first measuring a certain value relating to the driving stability by the means of at least one sensor of an ESP system. For example a sensor can measure the rotation velocity of an individual tire. This measured value can be evaluated by an evaluation device to determine the parameter for the individual tire as a numerical value. Furthermore, as an alternative or in addition to the sensors of an ESP- system, the parameters for an individual tire can be derived from capturing global driving stability parameters of the motor vehicle, for example by measuring a yaw ratio of the motor vehicle.

In a further advantageous embodiment of the invention, the captured parameter per tire can be a directional force, a dynamic pressure, torque acting on a specific tire and/or a grip of the specific tire on a road surface. These pa- rameters can also for example be derived from a nutation, rotation, and/or precision movement of the individual tire. The dynamic pressure gives especially precise information on the road conditions. The directional force, the torque acting on a specific tire and/or the grip of the specific tire on the road surface can indicate if or when the motor vehicle will break out. Due to the parameter being displayed in a different section for each individual tire, the driver can especially well asses which control command might improve a driving stability of the motor vehicle and/or how he can drive closer to a driving stability limit without losing control over the motor vehicle. In a further advantageous embodiment of the invention, the parameter is captured for each tire of the motor vehicle, whereby for each of the tires a corresponding section of the display device is controlled in dependency on the respective captured parameter. This gives the driver an especially good overview on the driving stability of the motor vehicle.

In a further advantageous embodiment of the invention, at least one additional parameter is determined in dependency on the captured parameters, whereby an additional section of the display device is controlled in dependency on the at least one additional parameter. For example, the additional parameter can be an overall and/or average grip, average dynamic pressure, average or total directional force, average or total torque on the motor vehicle. The additional parameter can be an aggregation of the other captured parameters. This can facilitate the assimilation of information by the driver. Furthermore, it supports the evaluation on how the parameter for each indi- vidual tire is connected to each other and how those connections influence the driving stability of the motor vehicle.

In a further advantageous embodiment of the invention, at least one ratio of at least one of the captured parameters to at least one threshold is determined, whereby a corresponding section of the display device is controlled in dependency on the determined ratio. This corresponding section can be an additional corresponding section to the section corresponding to the individual tire and its captured parameter. Alternatively, the section of the display device already corresponding to the individual tire can also be controlled simultaneously in dependency on the ratio and the captured parameter of this tire. This means that, for example, the display of a value of a captured parameter can be replaced by the display of the ratio of this captured parameter to a threshold. The ratio can be displayed for example as a percentage, a bar graph, and/or color coded display. For example, the ratio can be a percentage of the grip of an individual tire to its maximum possible grip. The threshold can be particular to each tire and/or to each parameter. The threshold can be a preset value. Alternatively, the threshold can be determined in relation to one or several characteristic numbers and/or forces act- ing on the individual tire. For example, the threshold can be determined in dependency on the captured parameters themselves. This allows for a determination of a dynamic ratio in dependency on a current driving stability and/or driving situation of the motor vehicle. The ratio gives the driver information about the driving stability of the motor vehicle that is especially easy to interpret.

In a further advantageous embodiment of the invention, a warning is issued in dependency on the determined ratio of at least one of the captured parameters to at least one threshold. This can mean that the warning is issued in dependency on at least one of the determined ratios. The warning can for example be issued as an audible and or visible signal. For example, the color of a section of the display device controlled in dependency on the ratio can be changed or a warning tone can be played. The warning can be issued when the ratio reaches a certain limit. For example, when a certain tire of the motor vehicle loses its grip on the road surface the corresponding section of the display device can be highlighted to alert the driver to this situation. This allows directing the attention of the driver to the most important sections of the display device. Additionally the driver can be alerted to critical driving conditions. In a further advantageous embodiment of the invention, for at least one of the tires a future parameter is predicted according to the currently and/or previously captured parameter, whereby a corresponding section of the display device is controlled in dependency on the predicted future parameter. Again, the corresponding section can be an additional section or the section corresponding to the individual tire can be controlled simultaneously in dependency on the captured parameter and the predicted future parameter. A single future parameter can be predicted according to several currently and/or pre- viously captured parameters. The future parameter gives the driver information about how the future driving stability of the motor vehicle might be according to the current and/or previous driving stability and/or current and/or previous driving maneuvers. This allows the driver to avoid unwanted driving situation in advance. For example, if the future parameter predicts a loss of control of the motor vehicle during a driving maneuver, the driver can give a timely control command to avoid such a loss of control.

In a further advantageous embodiment of the invention, a distribution of the parameter over time is recorded. This distribution over time can for example be stored internally on a storage device of the driver assistance system and/or externally on the internet or a mobile device such as a mobile phone or memory stick. This saved distribution can be accessed for a later review of driving performance. A corresponding section of the display device can be controlled in dependency on the recorded distribution of the corresponding parameter. Again, the corresponding section can be an additional section or the corresponding section can be controlled simultaneously in dependency on the distribution of the parameters and the captured parameter. The distribution can also include the determined ratio for a parameter and/or the determined additional parameter. The distribution can be displayed to the driver to allow him to assess driving stability over time. Furthermore, the distribution over time can be displayed in connection with a driving route on a geographical map. This allows the driver to assess where and when during his driving route the driving stability has reached critical values and due to which reasons. This especially allows the driver to increase his driving performance on a repetitive route such as a race track.

In a further advantageous embodiment of the invention, the recorded distribution of the parameters over time is compared to a preset distribution and/or a previously recorded distribution. Again a corresponding section of the dis- play device can be controlled in dependency on this comparison. The previous records can be of the same or other drivers. This allows to directly compare driver performances and also to create a driving score and/or a ranking. A second aspect of the invention concerns a driver assistance system for a motor vehicle. According to the invention, this driver assistance system is designed to perform an embodiment of the preceding described method. As has been explained in the preceding description of the method for operating such a driver assistance system, it allows a driver to control the driving stabil- ity of the motor vehicle especially well. The driver assistance system can include a display device. This display device comprises at least two different sections. The different sections can belong to a common display or each to their own display. The display device can also be part of an infotainment system of the motor vehicle. Furthermore, the driver assistance system can in- elude a sensor device. This can be a sensor device which is also used to measure values for an ESP system. Furthermore, the driver assistance system can include an evaluation device in order to be able to determine the captured parameters from the measured values by the sensor device. Any feature and advantage described for the method can also be considered to be a feature and advantage for the driver assistance system. The reverse also applies.

Further advantages, features, and details of the invention derive from the following description of preferred embodiments as well as from the drawing. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and/or shown in the figures alone can be employed not only in respective indicated combination but also in any other combination or taken alone without leaving the scope of the invention.

The drawing shows in:

Fig. 1 shows a schematic side view of a motor vehicle with a driver assistance system;

Fig. 2 illustrates a method to operate the driver assistance system according to Fig. 1 ; and Fig. 3 - 5 illustrate several examples of what can be displayed by a display device of the driver assistance system according to Fig. 1 if operated according to the method illustrated in Fig. 2. Fig. 1 shows a motor vehicle 10 with a driver assistance system 12 in a schematic side view. The driver assistance system 12 comprises a sensor device 14, an evaluation device 16 and a display device 18. A method for operating this driver assistance system 12 of the motor vehicle 10 comprises several steps. At least one parameter for at least one individual tire 20 of the motor vehicle 10 is captured, which is significant for a driving stability of the motor vehicle 10. This step is illustrated by the block 22 in Fig. 2. The display device 18 of the driver assistance system 12 is controlled in dependency on the at least one captured parameter. This step is illustrated by the block 24 in Fig. 2.

According to the invention the at least one parameter is captured per tire 20 for at least two individual tires 20 of the motor vehicle 10. For the given example, several parameters are captured for every tire 20 of the motor vehicle 10. The tires 20 can also be referred to as wheels. For each of the tires 20 a corresponding section 26 to 32 of the display device 18 is controlled in dependency on the respective captured parameters. This allows a driver of the motor vehicle 10 to use existing driving dynamics up to their maximum limits. It gives the driver a control feeling of driving dynamics and lets the driver drive more professional. The information displayed by means of the display device 18 can also calm the driver down as he is acutely aware of the driving stability of the motor vehicle 10. Overall it improves the understanding of the driver of the driving dynamics and driving stability of the motor vehicle 10 and thus allows him to control the motor vehicle 10 especially well. An example of what can be displayed on the display device 18 in Fig. 3 shows a specific section 26 to 32 for each tire 20. Section 26 and 28 correspond to the left and right front wheel of the motor vehicle 10, while sections 30 and 32 correspond to the left and right rear wheel. A representation of the wheels is displayed in the sections 26 to 32. Those representations can be animated. For example, the representations of the wheels and sections 26 and 28 can correspond to the current steering angle of those tires 20.

Each section 26 to 32 contains several bar graphs 36 to 42 that are controlled in dependency on the captured parameters for the corresponding tire 20. The bar graph 36 represents a torque on the corresponding tire 20. This torque can be derived from a precision, nutation or rotation of the tire 20. The bar graph 38 represents a directional force acting on the tire 20. The bar graph 40 illustrates the grip of the corresponding tire 20 on a road. Bar graph 42 shows the driver the current pressure inside the tire 20,

A further bar graph can show drive train torque allocation to each tire 20 to visualize the distribution. This is especially useful to illustrate the effects of a four-wheel drive. For example, the bar graph 42 could also display the torque allocated to an individual tire 20 instead of the current wheel pressure.

In all cases, the bar graphs 36 to 42 display a ratio of the respective captured parameters to a respective threshold value. This threshold value can for example be the maximum allowable pressure for a certain tire 20 wear, maxi- mum possible grip in a given driving situation and/or with a certain motor vehicle 10, and/or maximum allowable torque and/or force before a certain loss of driving stability occurs. This allows the driver to directly assess if he is driving close to the driving stability limits of the motor vehicle 10. Due to the fact that the sections 26 to 32 are each associated to an individual tire 20 of the motor vehicle 10, the driver can also assess which status of which tire 20 is the most critical. This allows him to adjust his driving commands accordingly. For example, he can modify his driving maneuver to shift forces from a tire 20 in a critical state to a tire 20 with a less critical state to overall achieve improved driving stability and/or driving performances.

Furthermore, Fig. 3 shows that one additional parameter is determined in dependency on the captured parameters, whereby an additional section 34 of the display device 18 is controlled in dependency on the at least one additional parameter. The additional parameter can for example be an aggrega- tion of several or ail captured parameters. For example, the evaluation de- Vice 16 assesses, if the driving style and/or the current driving maneuver and/or the driving stability is good, average or bad. Accordingly, the expression of an avatar 44 displayed in section 34 can be changed. This gives the driver direct feedback to the current driving stability of the motor vehicle 10. Also, the avatar 44 can entertain the driver and encourage him to drive more safely.

Fig. 4 shows an alternative or additional display to the one shown in Fig. 3. Again, four sections 26 to 32 are displayed, which correspond to the individ- ual tires 20 of the motor vehicle 10. These sections 26 to 32 can be displayed alternatively or in addition to the sections 26 to 32 according to Fig. 3. In both cases, for at least one parameter of the tires 20 a future parameter with for example future value is predicted according to the currently and/or previously captured parameter. The corresponding sections 26 to 32 of the display device 18 are controlled in dependency on the predicted future parameter. For example, in this case the predicted future parameter is the grip of the tires 20 on the road. Furthermore, a ratio of the predicted future parameters to a threshold is determined by the evaluation device 16. In de- pendency on this prediction, the sections 26 to 32 as shown in Fig. 4 are highlighted. For example, each section can be displayed differently brightly or in a different color. A possibility is to highlight the sections 26 to 32 green, yellow or red according to the ratio of the predicted future grip of each corresponding tire 20 to a maximum possible grip. Alternatively or in addition to, the bar graphs 36 to 42, as shown in Fig. 3, can be colored differently according to corresponding predicted future parameters. Both examples can also be understood as a warning that is issued to the driver. Critical predicted future parameters are highlighted and brought to the attention of the driver. This allows the driver to adjust his control commands in a timely manner. For example, this allows the driver to prevent the motor vehicle 10 from braking out and/or losing its driving stability. This allows the driver to drive more safely and/or more efficiently.

Fig. 5 shows how a recorded distribution of a parameter over time is dis- played by the display device 18. For example, an additional section 46 can show the dynamic pressure of an individual tire 20 over time. Such a recording allows the comparison with previous records and/or other drivers. The recorded distribution can also be used calculate a driving score and/or a ranking. Additionally, the distribution over time can be connected with a driv- ing route. For example, the distribution over time of a parameter can be displayed on the representation of a race track. This allows the driver to analyze on which parts of the race track he might control the motor vehicle 10 differently to improve his driving performance and/or driving stability. The examples for a display by the means of display device 18 according to Fig. 3 to 5 can also be called a total dynamic display. Especially for a motor vehicle 10 with an activated four-wheel drive, the driving assistance system 12 can illustrate the influence off an activated four-wheel drive on the driving stability of the motor vehicle 10. This illustration can also be displayed in comparison to a deactivated four-wheel drive. This can demonstrate to the driver of the motor vehicle 10 the effect of the activated four-wheel drive. Also the effects of other driver assistance systems can be made visible in a similar way.

The display can be 3-dimensional and/or holographic. All data can be displayed in a real time. A 3D-display can show an overview of each wheel status, or total mass status for forces and torsions such as precision, nutation and rotation. The driver can evaluate how far he is driving inside physical limits of the motor vehicle 10. Elements are displayed for torsion, force, slip and/or tire pressure as a combination of dynamic relevant scores for the individual driving abilities. Dynamic profiles can be stored and/or accessed locally or in a cloud. A central score system can be established to show which driver drives the safest and/or the most efficient. Also the display of the pa- rameters allows the driver to find the most fun and/or less stressful route. The information on which route is the most fun and/or less stressful, as well as the driver performance on this route, can be made accessible to other drivers. The display device 18 can be part of an infotainment-system of the motor vehicle 10. The display of information according to Fig. 3 to 5 can be activated and/or deactivated by pushing a corresponding button in the cockpit of the motor vehicle 10. For example, the display according to Fig. 3 could also include a schematic picture of the motor vehicle 10 in a top view so the driver can better identify which section 26 to 32 correspond to which tire 20 of the motor vehicle 10. All displays can be updated live while driving in order to visualize the influence of different driving maneuvers on the stability of the motor vehicle 10. This visualization can also show the influence of a four- wheel drive system as well as a drive train adjustment. This can especially illustrate the optimization of traction due to four-wheel system and the usage of front and/or rear wheel drive in percentage.

In combination with vehicle online services a customer can also upload the data of the captured parameters, especially their distribution over time, to a personal account. This data can be reviewed later, especially in an animated format. For example, the data can also be downloaded to a mobile device such as a smart-phone and/or a computer. The data can also include the taken route in a geographical map, predicted future parameters, determined additional parameters, driver profile information, car type information, deter- mined thresholds, warnings issued and driving performance compared to other drivers and/or previous performances.

Claims

PATENT CLAIMS:

1. A method for operating a driver assistance system (12) of a motor vehicle (10) comprising the following steps:

- Capturing at least one parameter for at least one individual tire (20) of the motor vehicle (10) which is significant for the driving stability of the motor vehicle (10);

- Controlling of a display device of the driver assistance system (12) in dependency on the at least one captured parameter, characterized in that

the at least one parameter is captured per tire (10) for at least two individual tires (10) of the motor vehicle (10), whereby for each of the at least two individual tires (20) a corresponding section (26 to 32) of the display device (18) is controlled in dependency on the respective captured parameter.

2. The method according to claim 1 ,

characterized in that

the captured parameter per tire can be a directional force (38), a dynamic pressure (42), a torque (36) acting on a specific tire (20) and/or a grip (40) of the specific tire (20) on a road surface.

3. The method according to claim 1 or 2,

characterized in that

the parameter is captured for each tire (20) of the motor vehicle (10), whereby for each of the tires (20) a corresponding section (26 to 32) of the display device (18) is controlled in dependency on the respective captured parameter.

4. The method according to any one of the preceding claims,

characterized in that

at least one additional parameter is determined in dependency on the captured parameters, whereby an additional section (34) of the display device (18) is controlled in dependency on the at least one additional pa- rameter.

5. The method according to any one of the preceding claims,

characterized in that

at least one ratio of at least one of the captured parameters to at least one threshold is determined, whereby a corresponding section (26 to 32) of the display device (18) is controlled in dependency on the determined ratio.

6. The method according to claim 5,

characterized in that

a warning is issued in dependency on the determined ratio of at least one of the captured parameter to at least one threshold.

7, The method according to any one of the preceding claims,

characterized in that

for at least one of the tires (20) a future parameter is predicted according to the currently and/or a previously captured parameter, whereby a corresponding section (26 to 32) of the display device (18) is controlled in de- pendency on the predicted future parameter.

8. The method according to any one of the preceding claims,

characterized in that

a distribution (46) of the parameter over time is recorded.

9. The method according to claim 8,

characterized in that

the recorded distribution (46) of the parameters over time is compared to a preset distribution and/or a previously recorded distribution.

10. A driver assistance system (12) for a motor vehicle (10) designed to perform a method according to any one of the preceding claims.