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EP-4741262-A1 - METHOD AND SYSTEM FOR EMERGENCY STOP OF A MOTOR VEHICLE

EP4741262A1EP 4741262 A1EP4741262 A1EP 4741262A1EP-4741262-A1

Abstract

Method for emergency stopping of a motor vehicle (1), comprising - continuous detection (S1) of objects (2, 3) in an area around the motor vehicle (1), and at least one parking location (4) on/at a roadway (5) traveled by the motor vehicle (1) during a journey of the motor vehicle (1), - continuous determination (S2) of a motion trajectory (6) for the motor vehicle (1) on which the motor vehicle (1) can be moved to at least one parking location (4) without collision with the objects (2, 3), - Determining (S3) an emergency or technical defect on or in the motor vehicle (1), - automatic control (S4) of the journey of the motor vehicle (1) on the movement trajectory (6) to the at least one parking location (4) where the motor vehicle (1) is automatically brought to a stop and system for carrying out the procedure.

Inventors

  • Baars, Maximilian, Dr.
  • WINTER, THOMAS

Assignees

  • Volkswagen Aktiengesellschaft

Dates

Publication Date
20260513
Application Date
20251103

Claims (10)

  1. Method for emergency stopping of a motor vehicle (1), comprising - continuous detection (S1) of objects (2, 3) in an area around the motor vehicle (1), and at least one parking location (4) on/at a roadway (5) traveled by the motor vehicle (1) during a journey of the motor vehicle (1), - continuous determination (S2) of a motion trajectory (6) for the motor vehicle (1) on which the motor vehicle (1) can be moved to at least one parking location (4) without collision with the objects (2, 3), - Determining (S3) an emergency or technical defect on or in the motor vehicle (1), - automatic control (S4) of the journey of the motor vehicle (1) on the movement trajectory (6) to the at least one parking location (4) where the motor vehicle (1) is automatically brought to a stop.
  2. Method according to claim 1, wherein the determination of the movement trajectory (6) is carried out using assistance systems (7) available in the motor vehicle (1), navigation data, GPS data, CAR2X or server backend information about the current traffic situation, or a combination thereof.
  3. Method according to claim 1 or 2, wherein the motor vehicle (1) has a steer-by-wire steering system (11) with a rack (12) and a rack actuator (13) and a rack motion profile is determined from the motion trajectory (6) and the rack (12) is moved by the rack actuator (13) according to the rack motion profile.
  4. Method according to claim 3, wherein the rack actuator (13) generates a lateral acceleration of the motor vehicle (1) of more than 2 m/ s² .
  5. Method according to claim 3 or 4, wherein the rack motion profile includes one or more of the following: a position of the rack (12), a speed of movement of the rack (12), an acceleration of a movement of the rack (12), a direction of movement of the rack (12), or a sequence of several of these.
  6. Method according to one of claims 3-5, wherein the technical defect is a defect in the steer-by-wire steering (11) by which the motor vehicle (1) can no longer be manually controlled.
  7. Method according to one of claims 3-6, wherein after stopping the motor vehicle (1) the rack actuator (13) is deactivated in such a way that the rack (12) can be moved by an external force acting on wheels (21).
  8. Method according to one of the preceding claims, wherein a speed profile and/or acceleration profile is determined with which the automatic control of the journey of the motor vehicle (1) on the movement trajectory (6) to the parking location (4) is carried out.
  9. Method according to one of the preceding claims, wherein the parking location (4) is on a hard shoulder (10).
  10. System (22) for carrying out a method for emergency stopping a motor vehicle (1) according to one of claims 1 - 9, comprising - an observation device (23) for continuously detecting (S1) objects around the motor vehicle (1), and at least one parking location (4) on/near a road (5) traveled by the motor vehicle (1) during a journey of the motor vehicle (1), - a motion trajectory determination device (24) for continuously determining (S2) a motion trajectory (6) for the motor vehicle (1), on which the motor vehicle (1) can be moved to at least one parking location (4) without collision with the objects (2, 3), - a control device (25) which can be activated upon detection (S3) of an emergency or technical defect on or in the motor vehicle (1) and is designed to automatically control (S4) the journey of the motor vehicle (1) on the movement trajectory (6) to the at least one parking location (4) where the motor vehicle (1) is automatically brought to a stop by the control device (25).

Description

The invention relates to a method and system for the emergency stop of a motor vehicle. Steer-by-wire (SbW) steering systems, which will be used in mass production in the automotive sector in the future, must exhibit significantly higher reliability than conventional steering systems. This is because SbW systems have no mechanical connection between the steering wheel and the steering gear. A complete failure of the steering system would render the vehicle unsteerable. Therefore, a complete failure must be prevented, and the effects of malfunctions must be detected early. Secondly, autonomous driving assistance systems also require increased reliability of the vehicle components. An SbW system consists of a force-feedback actuator (FFA), which detects the desired steering angle and provides realistic feedback to the driver. The SbW system also includes the steering gear (road-wheel actuator (RWA)), which translates the driver's input received from the FFA into a steering movement. In the event of a double fault in the steering system affecting the detection and/or transmission of the driver's command from the FFA to the RWA, or a critical fault in the driving system restricting the detection and implementation of the driver's command or the availability of other driving functions, the vehicle is in a degraded state. In this state, it is no longer possible to implement the steering angle command and thus cannot manually adjust the rack position to generate a wheel steering angle. "Degraded state" means that a defect exists in the steering system that renders manual control impossible. To ensure the safest possible driver input detection, the FFA (Driver Input Device) is designed with ASIL-D for safety objectives related to steering angle detection. Driver input detection is thus redundantly ensured. If a fault, double fault, or common-cause fault leads to a failure of the steering angle detection, the driver can no longer set a safe state (driving to the side of the road). Steer-by-brake (SbB) systems enable wheel-selective control of the brake components. and thus enable lateral guidance. However, the maximum achievable lateral acceleration is limited to 2 m/ s² , and a safe state cannot be reached because the driver's input can no longer be detected. Currently common fault handling in smoke and heat exhaust ventilation (SHEV) systems involves an electrical short circuit of the phases in the SHEV electric motor to maintain the current steering angle, or de-energizing the SHEV electric motor to follow a path predetermined by the axle geometry, typically straight-ahead driving. A system that doesn't detect driver input is unable to achieve a safe state because the performance requirements for lateral guidance are insufficient, and environmental monitoring is impossible without driver input. Short-circuiting the phases in the smoke and heat exhaust ventilation (SHEV) motor or de-energizing the SHEV motor also fails to achieve a safe state, as the vehicle becomes uncontrollable. While additional systems, such as the braking system, can bring the vehicle to a standstill, without adequate lateral guidance, it cannot be brought to a safe state, for example, to the side of the road. Therefore, neither of these options leads to a safe state. DE 10 2022 204 291 A1 This relates to a method for operating a steer-by-wire steering system, wherein the steer-by-wire steering system comprises a steering wheel actuator and a steering actuator that are coupled to each other via a signal connection. The steering actuator is controlled at at least one steerable wheel using first control parameters to set a target steering input derived from at least one steering wheel angle detected at the steering wheel. The steering wheel actuator is controlled at the steering wheel using second control parameters to set a feedback torque derived from at least one detected actual steering input of the at least one steerable wheel. In at least one selected driving situation, the second control parameters are modified when controlling the steering wheel actuator, or the system operates without feedback. However, this does not provide a solution to the problem described above. The purpose of the invention was to provide a solution to the problem described above. The problem is solved by a method and a system according to the independent claims. Specific embodiments are described in the dependent claims and this description. A procedure for the emergency stop of a motor vehicle is described, featuring Continuous detection of objects in an area around the motor vehicle, and at least one parking location on/near a road used by the motor vehicle during a journey of the motor vehicle, Continuous determination of a movement trajectory for the motor vehicle, on which the motor vehicle can be moved to at least one parking location without collision with the objects, Determining an emergency or technical defect on or in the motor vehicle, Automatic cont