SITUATION-DEPENDENT LIMITATION OF A STEERING BEHAVIOR

Abstract

A method for the situation-dependent calculation of a limitation for a steering torque and/or for calculating a control command for a steering system of a vehicle using a control device. Data are received about a vehicle environment, a planned trajectory, and/or data from sensors of the vehicle, a driving situation of the vehicle is ascertained based on the received data, a situation-dependent limitation of a steering behavior such as a steering torque is calculated based on the ascertained driving situation, and a control command for adjusting the calculated situation-dependent limitation of the steering behavior is output. A control device, a computer program as well as a machine-readable memory medium are described.

Claims

1-11. (canceled)

12. A method for a situation-dependent calculation of a limitation for a steering torque and/or for calculating a control command for a steering system of a vehicle using a control device, the method comprising the following steps: receiving data about a vehicle environment and/or a planned trajectory and/or data from sensors of the vehicle; ascertaining a driving situation of the vehicle based on the received data; calculating a situation-dependent limitation of a steering behavior based on the ascertained driving situation; outputting a control command for adjusting the calculated situation-dependent limitation of the steering behavior.

13. The method as recited in claim 12, wherein the situation-dependent limitation is a situation-dependent steering torque.

14. The method as recited in claim 12, wherein to ascertain the driving situation, data of a driving state and/or a current and planned trajectory of the vehicle, and/or a course of a traveled road and/or a behavior of adjacent road users and/or detected traffic sign, and/or a course of roads ascertained from map data and future courses of roads, are received.

15. The method as recited in claim 12, wherein the driving situation and the situation-dependent limitation of the steering behavior are ascertained using a vehicle model.

16. The method as recited in claim 12, wherein the driving situation and the situation-dependent limitation of the steering behavior are ascertained with using historical data and/or application-specific data and/or statistical data.

17. The method as recited in claim 12, wherein the situation-dependent limitation of the steering behavior causes a broadening or restriction of an existing limitation of a steering torque and/or a steering gradient.

18. The method as recited in claim 12, wherein a lower limit value and an upper limit value are calculated and adjusted for the situation-dependent limitation of the steering behavior.

19. The method as recited in claim 12, wherein the situation-dependent limitation of the steering behavior is adjusted in the form of a limitation of the steering torque at a steering wheel and/or an EPS motor and/or at at least one wheel, by an output control command.

20. The method as recited in claim 12, wherein the situation-dependent limitation of the steering behavior is calculated as a force limitation and/or an angle limitation and/or a position limitation, and adjusted by an output control command.

21. A control device for a situation-dependent calculation of a limitation for a steering torque and/or for calculating a control command for a steering system of a vehicle using a control device, the control device configured to: receive data about a vehicle environment and/or a planned trajectory and/or data from sensors of the vehicle; ascertain a driving situation of the vehicle based on the received data; calculate a situation-dependent limitation of a steering behavior based on the ascertained driving situation; output a control command for adjusting the calculated situation-dependent limitation of the steering behavior.

22. A non-transitory machine-readable memory medium on which is stored a computer program for a situation-dependent calculation of a limitation for a steering torque and/or for calculating a control command for a steering system of a vehicle using a control device, the computer program, when executed by a computer, causing the computer to perform the following steps: receiving data about a vehicle environment and/or a planned trajectory and/or data from sensors of the vehicle; ascertaining a driving situation of the vehicle based on the received data; calculating a situation-dependent limitation of a steering behavior based on the ascertained driving situation; outputting a control command for adjusting the calculated situation-dependent limitation of the steering behavior.

Description

BRIEF DESCRIPTION OF EXAMPLE EMBODIMENTS

[0032] FIG. 1 shows a schematic representation of a vehicle in accordance with an example embodiment of the present invention.

[0033] FIG. 2 shows a schematic representation of a flow diagram to illustrate a method according to one embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0034] FIG. 1 shows a schematic representation of a vehicle 1. Vehicle 1 may be a vehicle 1 that is operable in an automatic or semi-automatic manner, for instance. Vehicle 1 is particularly designed to carry out at least one driver assistance function.

[0035] The driver assistance function is used for the control of a transverse vehicle guidance of vehicle 1. To this end, a control device 2 is able to actuate actuators 4 of an electric power steering system 6 with the aid of control commands.

[0036] Vehicle 1 has sensors 8, 10 for scanning environment U and for ascertaining properties of vehicle 1. Vehicle 1 may be equipped with environment sensors 8 such as LIDAR sensors, camera sensors or radar sensors for this purpose.

[0037] In addition, state sensors 10 are provided for ascertaining measuring data pertaining to a vehicle state, e.g., acceleration sensors, yaw and rate-of-rotation sensors, steering angle sensors and the like.

[0038] In addition, GNSS sensors may be used in vehicle 1 for determining a position of vehicle 1 within environment U.

[0039] Sensors 8, 10 are connected to control device 2 in a data-transmitting manner. As a result, control device 2 can receive and evaluate measuring data from sensors 8, 10. A driving situation, for instance, is able to be ascertained with the aid of the received measuring data.

[0040] To ascertain the driving situation, data of a vehicle state such as a vehicle velocity, a yaw rate, a transverse acceleration or a steering angle, a current and planned trajectory of the vehicle, a course of a traveled road, a behavior of adjacent road users, detected traffic signs and/or courses of roads ascertained from map data and future courses of roads can be received. These input variables, individually or in any combination, may be used for a situation detection of the driving situation.

[0041] Depending on the development of vehicle 1, a situation-dependent limitation of the steering behavior of vehicle 1 is able to be adjusted. This may be accomplished in an automated manner with the aid of control device 2. In particular, the situation-dependent limitation can be implemented while a driver assistance system is activated.

[0042] For example, a limitation of a steering torque may become effective at a steering wheel 12 of vehicle 1, an EPS motor 14 of electronic power steering system 6, or at a wheel 16 of vehicle 1. Control device 2, for instance, is able to actuate actuators 4 for this purpose in order to induce or damp a steering wheel movement of steering wheel 12.

[0043] In particular, EPS motor 14 is able to adjust the steering position of wheels 16 across a dynamically situation-dependent range while the driver assistance system, e.g., a lane keeping assistant, is in operation. The limitation of the steering behavior may influence or adjust the maximum steering rate and a maximum steering width or steering angle of EPS motor 14, for instance.

[0044] Control device 2 is capable of adjusting the limitation or the dynamic variation of the steering behavior of vehicle 1.

[0045] FIG. 2 shows a schematic representation of a flow diagram to illustrate a method 20 according to one embodiment. Method 20 is used to adjust a limitation of a steering behavior of vehicle 1 and is preferably able to be carried out by control device 2. Method 20 is able to be developed in the form of a limiter.

[0046] The method of functioning of method 20 will be described in the following text. The functional block representation is not meant to restrict the physical realization of the functions on individual control devices 2. As a matter of principle, it is therefore irrelevant for the present invention on which control device the limitation of the steering behavior is calculated or whether the calculation is distributed to different control devices.

[0047] In a first step 22, a driving situation of vehicle 1 is ascertained based on input variables 21. For example, parking operations, slow cornering, fast cornering, straight-ahead driving on single-lane or multi-lane roads and the like may be taken into consideration as a driving situation of vehicle 1.

[0048] In order to ascertain the driving situation, data about a vehicle environment U, a planned trajectory, and/or data from sensors 8, 10 of vehicle 1 are able to be received. A driving situation of vehicle 1 will then be ascertained based on the received data.

[0049] Depending on the number and type of input signals or data used, it can be taken into account that the situation is unable to change rapidly in a random fashion. For example, due to the driving dynamics, vehicle 1 is unable to change from straight-ahead driving to cornering within fractions of a second.

[0050] In a further step 24, a situation-dependent limitation of a steering behavior of vehicle 1 such as a steering torque and/or a steering gradient is calculated based on the ascertained driving situation. A calculation of the limitation of the steering torque that is meaningful for and adapted to this situation is performed.

[0051] The limitation of the steering behavior is not exclusively restricted to a reduction or limitation of factors that are decisive for the steering. The limitation of the steering behavior, for instance, may also include a broadening of steering angle limits.

[0052] In a subsequent step 26, at least one control command for adjusting the calculated situation-dependent limitation of steering behavior 30 is output. For example, this may be realized by a software-based and/or hardware-based limiter. The limiter is then able to adapt a signal from a driver assistance system 28 in order to carry out the control commands of control device 2.

[0053] As an alternative, the control device as a driver assistance system is able to directly generate control commands to control the steering behavior of vehicle 1 and to drive actuators 4.

[0054] In the process, control device 2 may act directly on actuator 4 for implementing the limitation. As an alternative or in addition, control device 2 is able to forward control commands to further control devices (not shown) in order to realize a limitation of the steering behavior.

[0055] As a result of method 20, in a driving situation categorized as straight-ahead driving, for example, it is possible to allow only the amount of steering torque that is usually required for maintaining the straight-ahead driving and for adjusting for interference such as ruts or cross winds. During cornering, a greater steering torque or a greater steering torque gradient is able to be allowed.

[0056] For example, a curve radius or a dynamic curve characteristic such as in the case of a road featuring many twists and turns may be utilized as a measure of the limitation of the steering behavior.