Method for operating a driver assistance device for a motor vehicle, driver assistance device for a motor vehicle and computer program product

Abstract

The invention relates to a method for operating a driver assistance device (8) for a motor vehicle (1), having at least one driving stability system for supporting driving operation of the motor vehicle (1), wherein a system parameter set influencing at least one stability parameter of the motor vehicle (1) is set on the at least one driving stability system. Provision is made for a traffic parameter describing traffic in an environment surrounding the motor vehicle (1) to be detected by means of an environment detection device (9), and for the system parameter set to be selected as a function of the traffic parameter. The invention further relates to a driver assistance device (8) for a motor vehicle (1) and to a computer program product.

Description

[0001] The invention relates to a method for operating a driver assistance system for a motor vehicle, comprising at least one driving stability system for supporting the driving operation of the motor vehicle, wherein a system parameter set influencing at least one stability parameter of the motor vehicle is set on the at least one driving stability system. The invention further relates to a driver assistance system for a motor vehicle and a computer program product.

[0002] For example, the prior art document DE 10 2012 202 684 A1 is known. This document describes a method for vehicle and / or driving stability control for motor vehicles using a stabilization system, wherein a variable influencing stability is monitored and compared with an activation threshold. If the activation threshold is exceeded, a braking torque and / or drive torque is applied to at least one wheel of an axle of the motor vehicle for stabilization according to a predetermined control strategy.

[0003] It is provided that, depending on a variable describing the intensity of a determined yaw moment distribution and / or lateral moment distribution between the wheels of an axle, the control strategy of the vehicle and / or driving stability control is changed in such a way that the control sensitivity is increased by lowering the activation threshold and / or that the intensity of a possible subsequent control intervention is increased and / or the gradient with which the control intervention takes place is increased.

[0004] Furthermore, the document DE 10 2013 203 819 A1 discloses a driver assistance system for assisting the driver of a motor vehicle when leaving a predetermined lane, comprising a lane-keeping monitoring device connected to at least one lane detection unit and a warning and / or lateral guidance unit. The driver assistance system provides for the lane-keeping monitoring device to issue a warning and / or initiate lateral guidance if the motor vehicle approaches too closely to a defined boundary of the lane. The lane-keeping monitoring device acquires and evaluates information about a defined driving situation of the vehicle's own motor vehicle in such a way that a currently predetermined lane can be changed by shifting at least one defined boundary depending on the driving situation.

[0005] It is an object of the invention to propose a method for operating a driver assistance device for a motor vehicle, which has advantages over known methods, in particular further improves the driving stability of the motor vehicle across all situations and thus improves a driver's sense of safety of the motor vehicle even in critical driving situations.

[0006] This is achieved according to the invention with a method for operating a driver assistance system for a motor vehicle. It is provided that a traffic parameter describing traffic in the surroundings of the motor vehicle is detected by means of an environment detection device, and the system parameter set is selected depending on the traffic parameter.

[0007] Advantageous embodiments with useful further developments of the invention are specified in the dependent claims. It should be noted that the exemplary embodiments explained in the description are not limiting; rather, any variations of the features disclosed in the description, the claims, and the figures are feasible.

[0008] The method serves to operate the driver assistance device. The driver assistance device is preferably a component of the motor vehicle, but can of course also be present separately. For example, the driver assistance device is implemented using a control unit of the motor vehicle or it comprises the control unit. The driver assistance device fundamentally serves to support a driver of the motor vehicle in carrying out a driving operation of the motor vehicle. During driving operation, the motor vehicle moves at a speed other than zero, particularly in its forward direction of travel.

[0009] To support the driving operation or the driver in carrying out the driving operation of the motor vehicle, the driver assistance system comprises at least one driving stability system. The driving stability system influences the driving operation of the motor vehicle and, in doing so, affects the stability parameter of the motor vehicle. The stability parameter describes various aspects of the driving operation, for example, the accuracy with which the motor vehicle follows a specified lane, the rotational rates and / or rotational accelerations that occur during driving, and / or the degree of slip of the motor vehicle or of the motor vehicle's wheels on a surface.

[0010] Wherever reference is made to the driving stability system or the at least one driving stability system within the scope of this description, the statements are always to be understood analogously. The statements regarding the driving stability system also apply to the at least one driving stability system, and vice versa. It may be provided that the driver assistance system has only a single driving stability system. However, it is particularly preferred that it comprises multiple driving stability systems. The statements regarding the driving stability system are analogously applicable to each of the multiple driving stability systems.

[0011] While the motor vehicle is being driven, the system parameter set is adjusted on the driving stability system. The system parameter set comprises at least one system parameter that influences the at least one stability characteristic. Of course, the system parameter set can have exactly one system parameter or multiple system parameters. Whenever the system parameter is mentioned in this description, this always means at least one system parameter, and the corresponding explanations can also be applied to each of several system parameters, if present. The term “system parameter set” in this description represents the at least one system parameter or serves as a collective term for the one or more system parameters. Statements about the system parameter set therefore always also relate to the system parameter or the at least one system parameter.

[0012] The vehicle's handling behavior is influenced by the system parameter set. This means that, in a given driving situation, the vehicle exhibits a first handling behavior and, accordingly, a first value of the stability parameter if a first system parameter set is configured on the driving stability system. However, if a second system parameter set different from the first system parameter set is configured on the driving stability system, a second handling behavior and a second value of the stability parameter will occur in the driving situation.

[0013] For example, the system parameter set or the system parameter includes at least one threshold value of the driving stability system, i.e., for executing a driving stability program of the motor vehicle. In particular, it is intended to temporarily operate one or more driving stability systems in such a way that the motor vehicle exhibits better lane guidance but poorer traction, and temporarily operate with poorer lane guidance and better traction. However, the system parameter set is always selected in such a way that it complies with all ASIL requirements.

[0014] It is known to select the system parameter set such that the best possible compromise is achieved between different stability parameters, for example, between traction, tracking, and driving stability. In particular, the system parameter is defined as a traction slip threshold. If the vehicle's traction slip is exceeded, a traction control system is activated to reduce the traction slip. The traction slip threshold is selected such that the vehicle exhibits high traction with acceptable tracking.

[0015] It may be provided that the stability parameter is selected depending on at least one driving state parameter of the motor vehicle. For example, one of the following variables is used as the driving state parameter: driving speed, longitudinal acceleration, lateral acceleration, degree of understeer, and degree of oversteer of the motor vehicle. Preferably, several or all of the aforementioned driving state variables are used to determine the system parameter set or the at least one system parameter in order to always achieve the best possible compromise between traction and tracking or driving stability in every driving situation.

[0016] However, the driving behavior desired by the driver of a motor vehicle depends not only on the driving state, but also, or alternatively, to a large extent on the driving situation of the vehicle. For example, if another vehicle, especially a truck, is approaching the vehicle on a narrow road, the driver's priorities shift from traction to precise lane guidance. Such a shift in priorities, dictated by the traffic situation, is not taken into account by existing driver assistance systems.

[0017] Therefore, the driver assistance system according to the invention has an environment detection device, by means of which the traffic in the vicinity of the motor vehicle is detected. The environment detection device provides the traffic parameter as an output variable, which describes the traffic in the vicinity of the motor vehicle. For example, the traffic parameter describes traffic density, i.e., the number of other motor vehicles in the vicinity of the motor vehicle.

[0018] The traffic parameter can, for example, contain a relative speed of at least one of the other motor vehicles with respect to the motor vehicle. Based on the traffic parameter, it can be determined whether the other motor vehicle is approaching or moving away from the motor vehicle. To always give the driver of the motor vehicle a high degree of control over the driving operation of the motor vehicle, enabling them to react quickly and effectively to the traffic in the vicinity of the motor vehicle, the system parameter set is selected depending on the traffic parameter describing the traffic in the vicinity of the motor vehicle and is subsequently adjusted in the driving stability system.

[0019] In a given driving situation, the stability parameter depends directly on the traffic parameter detected by the environment detection device. Additionally, as already explained, the system parameter set can depend on at least one driving state variable of the motor vehicle. The described procedure enables particularly reliable driving of the motor vehicle. In particular, it gives the driver a high degree of control over the driving of the motor vehicle, allowing them to react effectively to the traffic in the vehicle's surroundings.

[0020] A further development of the invention provides that at least one of the following parameters is used as the stability parameter: lane guidance parameter, driving stability parameter, and traction parameter. The lane guidance parameter describes the lane guidance or tracking stability of the motor vehicle. For example, the larger the lane guidance parameter, the better the motor vehicle maintains a lane specified by the driver.

[0021] The driving stability parameter describes the stability of the motor vehicle with respect to at least one rotational movement and / or rotational acceleration of the motor vehicle about at least one axis, for example, about a longitudinal axis, transverse axis, or vertical axis of the motor vehicle. The rotational movement about the longitudinal axis is also referred to as rolling movement, the rotational movement about the transverse axis as pitching movement, and the rotational movement about the vertical axis as yaw movement. The driving stability parameter thus describes the stability of the motor vehicle with respect to rolling, pitching, or yawing of the motor vehicle.

[0022] Finally, the traction parameter describes the traction of the motor vehicle on the surface on which it is located, for example on a roadway. The higher the traction parameter, the lower the slip of the motor vehicle or its wheels on the surface. At least one of the parameters mentioned, but preferably several or even all of the parameters, is used as a stability parameter. The system parameter set configured on the driving stability system can therefore influence precisely one of the parameters or several or all of the parameters. The use of at least one of the parameters enables the advantages already mentioned.

[0023] A further development of the invention provides that a roadway used by the motor vehicle, in particular comprising at least one lane, and / or an oncoming lane, in particular comprising at least one oncoming lane, are used as the surroundings. The surroundings detection device thus detects the traffic on the roadway and / or the oncoming lane. The roadway is understood to be a lane on which the motor vehicle is moving in its direction of travel. If one or more other motor vehicles are on the roadway, they are usually also moving in the direction of travel, preferably at a similar speed to the motor vehicle.

[0024] The oncoming lane, on the other hand, is a lane that is different from the lane on which the motor vehicle is located. One or more motor vehicles on the oncoming lane are moving in a direction opposite to the main direction of travel of the motor vehicle. Both the roadway and the oncoming lane can comprise one or more lanes that are visually separated from one another by appropriate lane markings. The lanes of the oncoming lane can also be referred to as oncoming lanes. The environment detection device preferably only records traffic on the roadway and / or the oncoming lane, but not off the roadway and / or the oncoming lane. This ensures that the driver can plausibly understand the selection of the system parameter set by the driver assistance system at any time.

[0025] A further development of the invention provides that traffic density is used as a traffic parameter. This has already been pointed out. Traffic density describes the density of other motor vehicles in the vicinity of the motor vehicle, in particular on the roadway and / or the oncoming lane. The higher the traffic density, the greater the importance of good directional stability of the motor vehicle, whereas the importance of traction decreases. In particular, it is provided that lane guidance or directional stability is given greater priority the higher the traffic density, even if this results in poorer traction. Due to this measure, the driver of the motor vehicle always has the option of maintaining a sufficient distance between the motor vehicle and the at least one other motor vehicle by selecting the appropriate lane.

[0026] A further development of the invention provides that the system parameter set is selected from several stored system parameter sets based on the traffic parameter and is adjusted in the driving stability system. The system parameter sets are stored in the driver assistance device or the driving stability system, preferably fixed and / or unchangeable. This means that the system parameter sets are factory-set and cannot subsequently be changed by the driver, at least not while the motor vehicle is being driven. However, it may be provided that the system parameter sets are adapted, in particular modified, for example, during maintenance of the motor vehicle.

[0027] For example, the system parameter sets are stored with an associated value for the traffic parameter. If the traffic parameter detected by the environment detection device corresponds to the stored value for one of the stored system parameter sets, this system parameter set is selected from the system parameter sets and adjusted on the driving stability system. It can of course also be provided that the system parameter set is selected and adjusted based on the traffic parameter using a different procedure. Selecting the system parameter set from the system parameter sets has the advantage that all necessary safety specifications can always be met, since, in particular, all legal requirements for the driving stability of the motor vehicle are met by each of the system parameter sets.

[0028] A further development of the invention provides that the system parameter set is selected for a first value of the traffic parameter in the direction of higher directional stability and / or higher driving stability and / or lower traction, and for a second value of the traffic parameter in the direction of lower directional stability and / or lower driving stability and / or higher traction. The first value of the traffic parameter occurs, for example, at a higher traffic density and the second value at a lower traffic density. In the first case, directional stability and / or driving stability are given higher priority than traction; in the second case, it is the other way around. The system parameter set therefore comprises, as a system parameter, for example, a threshold value of at least one driving stability system. The described procedure ensures that the driver can operate the motor vehicle effectively.

[0029] A further development of the invention provides that at least one of the following control systems is used as the driving stability system: a traction control system, a braking control system, a drag torque control system, a vehicle stability control system, and a torque distribution control system. The traction control system regulates the traction slip of the motor vehicle on the road surface toward a threshold value. For example, the traction control system is only active when the traction slip of the motor vehicle is greater than the threshold value. The threshold value can be used as a system parameter.

[0030] The brake control system is, for example, an anti-lock braking system. This controls the brake slip of the motor vehicle on the surface towards a threshold value, which in turn can be used as a system parameter. Preferably, the brake control system is also only active if the brake slip is greater than the threshold value. The drag torque control system adjusts the drag torque of a drive unit of the motor vehicle, in particular in such a way that the stability characteristic of the motor vehicle is influenced. It can be provided that the drag torque control system, together with the brake control system, adjusts the brake slip towards its threshold value.

[0031] The vehicle stability control system serves to ensure the stability of the motor vehicle. For example, the yaw rate and / or angular acceleration of the motor vehicle about one or more of its axes are adjusted toward a desired threshold value. Axes can be understood, for example, as a longitudinal axis, a transverse axis, and / or a vertical axis of the motor vehicle. The threshold value is preferably included as a system parameter in the system parameter set.

[0032] The torque distribution control system is, for example, a torque vectoring system, by means of which the drive torque provided by the drive unit can be specifically distributed to the wheel axles or wheels of the vehicle. The torque distribution control system works together with the traction control system, for example, to adjust the traction control system of the vehicle toward the threshold value. Using one or more of these control systems, a particularly effective influence on the stability parameter is achieved.

[0033] A further development of the invention provides that at least one of the following devices is used as the environment detection device: camera device, radar device, lidar device, and sonar device. The camera device is understood to be an environment detection device that has at least one camera used to record images of the environment. These images are further processed by the driver assistance device to determine the traffic parameter. The radar device uses radio measurement technology or radar to observe the environment. The lidar device is fundamentally similar to the radar device, but uses light, in particular laser light, to detect the environment of the motor vehicle. In the case of the sonar device, sound pulses are used to observe the environment.

[0034] The aforementioned devices are sufficiently well known, so they will not be discussed in detail. Preferably, the surroundings detection device serves to observe the surroundings in front of the motor vehicle, in particular exclusively. For example, the surroundings detection device comprises exactly one of the aforementioned devices, but preferably it comprises several or even all of the aforementioned devices. In any case, a high detection accuracy for the traffic parameter is achieved.

[0035] The invention further relates to a driver assistance device for a motor vehicle, in particular for carrying out the method according to the embodiments within the scope of this description, having at least one driving stability system for supporting driving operation of the motor vehicle, wherein a system parameter set influencing at least one stability parameter of the motor vehicle can be set on the at least one driving stability system. It is provided that the driver assistance device is provided and configured to detect a traffic parameter describing traffic in an environment of the motor vehicle by means of an environment detection device and to select the system parameter set depending on the traffic parameters.

[0036] The advantages of such an approach or such a design of the driver assistance system have already been pointed out. Both the driver assistance system and the method for its operation can be further developed according to the explanations in this description, so reference is made to these in this regard.

[0037] Furthermore, the invention relates to a computer program product comprising commands that cause the driver assistance system for the motor vehicle to execute the described method according to the details of this description. Regarding the advantages and possible advantageous developments, reference is made to the entire description.

[0038] The features and feature combinations described in the description, in particular the features and feature combinations described in the following description of the figures and / or shown in the figures, can be used not only in the respective combination specified, but also in other combinations or on their own, without departing from the scope of the invention. Thus, embodiments are also considered to be encompassed by the invention that are not explicitly shown or explained in the description and / or the figures, but which follow from or can be derived from the explained embodiments.

[0039] The invention will be explained in more detail below with reference to the exemplary embodiments shown in the drawings, without limiting the invention. Fig. 1 a schematic representation of a motor vehicle with a driver assistance device in which a system parameter set influencing a stability parameter of the motor vehicle is selected depending on a traffic parameter.

[0040] The Fig.1 shows a schematic representation of a motor vehicle 1 with a drive device 2 (only indicated) and an energy storage device 3, which is arranged, for example, in some areas in an underbody of the motor vehicle 1. The motor vehicle 1 has, for example, two wheel axles 4 and 5, wherein the wheel axle 4 is designed as the front wheel axle and the wheel axle 5 as the rear wheel axle. At least two wheels 6 of the motor vehicle 1 are arranged on each of the wheel axles 4 and 5. At least one of the wheel axles 4 and 5 is the driven wheel axle. It can also be provided that both wheel axles 4 and 5 are each driven at least temporarily. For example, the wheel axle 4 is permanently connected to the drive device 2 and the wheel axle 5 only temporarily, or vice versa. The number of wheels 6 driven by the drive direction 2 is adjustable in this respect.

[0041] Only indicated is an electric traction motor 7 of the drive device 2, which serves as the drive unit. The traction motor 7 is electrically connected to the energy storage device 3 and serves, at least temporarily, to provide a drive torque directed toward driving the motor vehicle 1. The traction motor 7 is connected to the wheel axles 4 and 5, for example, directly or indirectly via a manual transmission.

[0042] The motor vehicle 1 additionally has a driver assistance system 8, which has at least one driving stability system, by means of which the driving operation of the motor vehicle 1 is at least temporarily supported. A system parameter set can be set on the driving stability system, which influences one or more stability parameters of the motor vehicle. The stability parameter is understood to be, for example, a lane guidance parameter, a driving stability parameter, and / or a traction parameter.

[0043] The driver assistance device 8 comprises an environment detection device 9, by means of which a traffic parameter is detected that describes traffic in the environment of the motor vehicle 1. Depending on the traffic parameter, the system parameter set is determined and adjusted to the driving stability system of the driver assistance device 8. The environment detection device 9, or the traffic parameter determined by it, influences the stability characteristic of the motor vehicle 1. This gives the driver a high degree of control over the motor vehicle 1, since it always optimally adapts to the traffic situation or is optimally adjusted to it. LIST OF REFERENCE SYMBOLS: 1 motor vehicle 2 drive device 3 energy storage 4 wheel axle 5 wheel axle 6 wheel 7 Traction machine 8 Driver assistance system 9 Environment detection device QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2012 202 684 A1

[0002] DE 10 2013 203 819 A1

[0004]

Claims

[1] Method for operating a driver assistance device (8) for a motor vehicle (1), having at least one driving stability system for supporting driving operation of the motor vehicle (1), wherein a system parameter set influencing at least one stability characteristic of the motor vehicle (1) is set on the at least one driving stability system, characterized by that a traffic parameter describing traffic in an environment of the motor vehicle (1) is detected by means of an environment detection device (9) and the system parameter set is selected as a function of the traffic parameter. [2] Method according to claim 1, characterized by that at least one of the following parameters is used as a stability parameter: lane guidance parameter, driving stability parameter and traction parameter. [3] Method according to one of the preceding claims, characterized bythat a roadway used by the motor vehicle (1) and / or an oncoming roadway are used as the environment. [4] Method according to one of the preceding claims, characterized by that traffic density is used as a traffic parameter. [5] Method according to one of the preceding claims, characterized by that the system parameter set is selected from several stored system parameter sets based on the traffic parameter and set on the driving stability system. [6] Method according to one of the preceding claims, characterized by that the system parameter set is selected in the direction of higher directional stability and / or higher driving stability and / or lower traction for a first value of the traffic parameter and in the direction of lower directional stability and / or lower driving stability and / or higher traction for a second value of the traffic parameter. [7] Method according to one of the preceding claims, characterized by that at least one of the following control systems is used as the driving stability system: a traction control system, a brake control system, a drag torque control system, a vehicle stability control system and a torque distribution control system. [8] Method according to one of the preceding claims, characterized by that at least one of the following devices is used as the environment detection device (9): a camera device, a radar device, a lidar device and a sonar device. [9] Driver assistance device (8) for a motor vehicle (1), in particular for carrying out the method according to one or more of the preceding claims, with at least one driving stability system for supporting driving operation of the motor vehicle (1), wherein a system parameter set influencing at least one stability characteristic of the motor vehicle (1) can be set on the at least one driving stability system, characterized by that the driver assistance device (8) is provided and designed to detect a traffic parameter describing traffic in an environment of the motor vehicle (1) by means of an environment detection device (9) and to select the system parameter set depending on the traffic parameter. [10] Computer program product comprising instructions which cause the driver assistance device (8) according to claim 9 to carry out the method according to one or more of claims 1 to 8.

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