CONTROL SYSTEM AND METHOD FOR ASSISTING OR OBTAINING A RELIABLE STEERING OPERATION OF A MOTOR VEHICLE WHICH IS CAPABLE OF DRIVING AT LEAST SEMI-AUTONOMOUSLY

Abstract

Control system and method which is adapted for use in a motor vehicle and intended to effect an at least semi-autonomous driving operation of the motor vehicle by means of assigned actuators on the basis of environmental data which are obtained from one or more environment sensors assigned to the motor vehicle, and wherein the control system is adapted and intended to detect a failure of a conventional steering system of the motor vehicle and attempt a change of direction of the vehicle, which corresponds to a desired steering angle, from current driving parameters by means of matched acceleration and/or deceleration interventions at individual wheel drives or wheel brakes, respectively, of the vehicle.

Claims

1. A control system which is adapted for use in a motor vehicle and intended to effect an at least semi-autonomous driving operation of the motor vehicle by means of assigned actuators on the basis of environmental data and intra-system sensor data which are obtained from one or more sensor/s assigned to the motor vehicle, and wherein the control system is adapted and intended to detect a failure of a conventional steering system of the motor vehicle and attempt a change of direction of the vehicle, which corresponds to a desired steering angle, from current driving parameters by means of matched acceleration and/or deceleration interventions at individual wheel drives or wheel brakes, respectively, of the vehicle.

2. Control system according to claim 1, in which the driving parameters include one or more of the parameters: vehicle speed, vehicle acceleration, yaw rate of the vehicle, desired and actual steering angle, speed of individual wheels of the vehicle, and slip state of individual wheels of the vehicle relative to the ground.

3. Control system according to claim 1, in which the control system is adapted and intended to effect the matched acceleration and/or deceleration interventions in such a manner that, in order to effect a change of direction of the vehicle to the let, a left rear wheel of the vehicle is decelerated and/or a right front wheel of the vehicle is accelerated.

4. Control system according to claim 1, in which the control system is adapted and intended to effect the matched acceleration and/or deceleration interventions in such a manner that, in order to effect a change of direction of the vehicle to the right, a right rear wheel of the vehicle is decelerated and/or a left front wheel of the vehicle is accelerated.

5. Method of effecting an at least semi-autonomous driving operation of a motor vehicle on the basis of environmental data obtained from one or more environment sensor/s assigned to the vehicle by means of an electronic control and by means of actuators downstream of the control of the motor vehicle, comprising the following steps: detecting the presence of an exceptional situation because of an at least partial failure of components of a steering system of the motor vehicle; and attempting a change of direction of the vehicle, which corresponds to a desired steering angle, from current driving parameters by means of matched acceleration and/or deceleration interventions at individual wheel drives or wheel brakes, respectively, of the vehicle.

6. Method according to claim 5, in which there are evaluated as the driving parameters one or more of the parameters: vehicle speed, vehicle acceleration, yaw rate of the vehicle, desired and actual steering angle, speed of individual wheels of the vehicle, and slip state of individual wheels of the vehicle relative to the ground.

7. Method according to claim 5, in which the matched acceleration and/or deceleration interventions are effected in such a manner that, for a change of direction of the vehicle to the left, a left rear wheel of the vehicle is decelerated and/or a right front wheel of the vehicle is accelerated.

8. Method according to claim 5, in which the matched acceleration and/or deceleration interventions are effected in such a manner that, for a change of direction of the vehicle to the right, a right rear wheel of the vehicle is decelerated and/or a left front wheel of the vehicle is accelerated.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Further objects, features, advantages and possible uses will become apparent from the following description of embodiments, which are not to be interpreted as being limiting, with reference to the accompanying drawings. All the features described and/or illustrated, individually or in any desired combination, show the subject-matter disclosed herein independently of their grouping in the claims or their dependencies. The dimensions and proportions of the components shown in the figures are not necessarily true to scale; they may differ from those illustrated here in embodiments that are to be implemented.

[0012] FIG. 1 shows, in schematic form, parts of the control system architecture of a (semi-)autonomous passenger vehicle.

[0013] FIG. 2 shows, in schematic form, a model for lateral wheel steering to the left presented here.

[0014] FIG. 3 shows, in schematic form, a model for lateral wheel steering to the right presented here.

DESCRIPTION

[0015] FIG. 1 shows, in schematic form, parts that are of interest here of a control system (autonomous drive control) which is adapted and intended for use in a motor vehicle. This control system has an autonomous drive control. This receives environmental data and intra-system (sensor) data from one or more sensor/s assigned to the motor vehicle. On the basis of these data, the control system intervenes in the driving operation of the motor vehicle, by means of associated actuators (steering, drives, brakes, etc.), in such a manner that an at least semi-autonomous driving operation is effected. To this end, the autonomous drive control communicates either with the actuators (steering, drives, brakes, etc.) directly or with an individual brake control of each wheel indirectly. In the arrangement shown, the autonomous drive control addresses the steering of the front wheels FL, FR and the (electric) wheel drives directly. For individual braking interventions at each wheel, the autonomous drive control sends corresponding commands to the individual brake control of each wheel, which in turn controls the respective wheels FL, FR, RL, RR individually.

[0016] In trouble-free operation, the control system is capable of generating actuator signals (steering angle, propulsion) for the autonomous operation of the motor vehicle from the environment sensor data and the intra-system data. The control system is additionally capable of detecting a failure of a conventional steering system of the motor vehicle from the environment sensor data and the intra-system sensor data. This is possible, for example, as a result of the fact that a predetermined steering angle signal does not correspond to a rotation of the motor vehicle about its vertical axis, the rotation being determined with a signal from a yaw rate sensor. This can be established by the system control by comparison.

[0017] If an exceptional situation is present—shown in FIGS. 2 and 3 by means of broken connections between the autonomous drive control and the steering actuators, which set the steering angle of the front wheels—the control system is capable of attempting a change of direction of the vehicle, which corresponds to a desired steering angle, from current driving parameters by means of matched acceleration and/or deceleration interventions at individual wheel drives or wheel brakes, respectively, of the vehicle.

[0018] For the matched acceleration and/or deceleration interventions at individual wheel drives or wheel brakes, respectively, of the vehicle, the control system uses in one solution variant the driving dynamics control system which is (in any case) present in the vehicle. To that end, the autonomous drive control can communicate, for example, with the individual brake control of each wheel of the driving dynamics control system and transmit corresponding commands. The autonomous drive control can check the result of the deceleration interventions again with the yaw rate sensor, for example, and make a re-adjustment

[0019] Evaluated driving parameters include in some solution variants: vehicle speed, vehicle acceleration, yaw rate of the vehicle, desired and actual steering angle, speed of individual wheels of the vehicle, and slip state of individual wheels of the vehicle relative to the ground.

[0020] The control system effects the matched acceleration and/or deceleration interventions in such a manner that, for a desired change of direction of the vehicle to the left, a left rear wheel of the vehicle is decelerated by application of a braking torque a− and—where possible—a right front wheel of the vehicle is accelerated by application of an acceleration torque a+. Individual acceleration of a (front) wheel of the vehicle is generally possible only in the case of (partially) electric vehicles which have individual electric drives for each wheel (FIG. 2). In an analogous manner, a change in direction of the vehicle to the right is effected by the control system by decelerating a right rear wheel by application of a braking moment a− and—where possible—and/or accelerating a left front wheel of the vehicle by application of an acceleration torque a+ (FIG. 3).

[0021] The system architecture illustrated in the figures, in which the various components in communication with one another are connected to one another directly, is not obligatory; the components may also communicate with one another through a data bus.

[0022] The variants described above, and the structural and operational aspects thereof, serve merely for better understanding of the structure, mode of operation and properties; they do not limit the disclosure to the embodiments. Some of the figures are schematic, some important properties and effects being shown on a significantly enlarged scale in order to make the functions, principles of operation, technical configurations and features clear. Any mode of operation, principle, technical configuration and feature disclosed in the figures or in the text can be combined freely and as desired with all the claims, any feature in the text and in the other figures, other modes of operation, principles, technical configurations and features which are contained in or follow from this disclosure, so that all conceivable combinations are to be associated with the described variants. Also included are combinations between ail the individual remarks in the text, that is to say in every paragraph of the description, in the claims and also combinations between different variants in the text in the claims and in the figures. The claims also do not limit the disclosure and thus the possible combinations of all the described matures with one another. All the disclosed features are also explicitly disclosed herein individually and in combination with all the other features.