Failure mode effects mitigation in drive-by-wire systems

• US 8,234,045 B2
• Filed: 09/24/2008
• Issued: 07/31/2012
• Est. Priority Date: 09/24/2008
• Status: Expired due to Fees

• Current Assignee: Bosch Rexroth Corporation (Robert Bosch GmbH), Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Spadafora, William, Llewellyn, David, Paielli, Perry, Kramer, Jason
• Primary Examiner(s): Trammell, James P
• Assistant Examiner(s): Alsomiri, Majdi
• Application Number:
  US12/236,957
• Publication Number:
  US 20100076650A1
• Time in Patent Office: 1,406 Days
• Field of Search: 701/1, 701/43, 701/48, 701/53, 701/71, 340/507, 700/285
• US Class Current: 701/43
• CPC Class Codes: B62D 5/003 Backup systems, e.g. for manual steering B62D5/30 takes precedence
• CPC Class Codes: B62D 9/002 combined with means for differentially distributing power on the deflectable wheels during cornering
• CPC Class Codes: B62D 9/005 Emergency systems using brakes for steering

Abstract

Systems and methods for mitigating failure mode effects in a steer-by-wire system. The system includes a controller configured to alter a direction of the vehicle when the controller is in a failure mode. A steering device is coupled to a detector. The detector is configured to detect a steering input from a driver and output a signal representative of the steering input. A first actuator is coupled to a first control device. The first control device is configured to generate a first control signal representative of the steering input when the controller is in the failure mode. The first actuator alters the direction of the vehicle by removing energy from the vehicle. A second actuator is coupled to a second control device. The second control device is configured to generate a second control signal representative of the steering input when the controller is in the failure mode. The second actuator alters the direction of the vehicle by adding energy to the vehicle.

Claims

1. A steer-by-wire failure mode mitigation system for a vehicle, the system comprising:

a driver input device configured to receive a steering input from a driver of the vehicle;

a detector configured to detect the steering input and to output a signal representative of the steering input;

a first control device;

a second control device that is different than the first control device;

a third control device that is different than the first control device and the second control device;

a controller configured to operate in either a first operational mode or a failure mode, the controller coupled to the detector, the first control device, the second control device, and the third control device, the controller configured to

determine whether the first, second, and third control devices are functioning properly,

operate in the failure mode if one or more of the control devices are functioning improperly, and, while in the failure mode, send command input signals only to those control devices that are functioning properly to control and monitor those control devices;

a first actuator coupled to the first control device, the first control device configured to receive a first command input signal from the controller, when the controller is in the first operational mode, generate a first control signal representative of the steering input, and transmit the first control signal to the first actuator;

wherein the first actuator is configured to generate a first mechanical output to alter a direction of a first wheel and a second wheel;

a second actuator coupled to the second control device, the second control device configured to receive the first command input signal from the controller, when the controller is in the failure mode, generate a second control signal representative of the steering input, and transmit the second control signal to the second actuator;

wherein the second actuator is configured to generate a second mechanical output to exert a first force on the first wheel in a first direction; and

a third actuator coupled to the third control device, the third control device configured to receive the first command input signal from the controller, when the controller is in the failure mode, generate a third control signal representative of the steering input, and transmit the third control signal to the third actuator;

wherein the third actuator is configured to generate a third mechanical output to exert a second force on the second wheel in a second direction.

2. The system of claim 1, wherein the first force is a braking force and the second force is a torque.

3. The system of claim 1, wherein the driver input device is a steering wheel.

4. The system of claim 1, wherein the first control device is a steering control device, the second control device is a braking control device, and the third control device is a drivetrain control device.

5. The system of claim 1, wherein the first force and the second force alter a direction of the vehicle in accordance with the steering input.

6. The system of claim 1, wherein the failure mode includes a malfunction in at least one of the first control device or the first actuator.

7. The system of claim 1, wherein the first force and the second force alter a direction of the vehicle during a control response time interval.

8. The system of claim 1, wherein the first force removes energy from the vehicle and the second force adds energy to the vehicle.

9. The system of claim 7, wherein the control response time interval is controlled by adding energy to or removing energy from the vehicle at different rates.

10. A method for steering a vehicle during a steer-by-wire failure, the method comprising:

receiving a steering input from a driver of the vehicle;

detecting the steering input with a detector, the detector outputting a signal representative of the steering input to a controller configured to operate in either a first operational mode or a failure mode, the controller configured to

determine whether a plurality of control devices are functioning properly and to send command input signals,

operate in the failure mode if one or more of the plurality of control devices are functioning improperly, and, while in the failure mode, send command input signals only to those control devices that are functioning properly to control and monitor those control devices;

receiving, at a first control device, a first command input signal from the controller when the controller is in a first operational mode, the first control device generating a first control signal representative of the steering input and transmitting the first control signal to a first actuator;

wherein the first actuator alters a direction of a first wheel and a second wheel;

receiving, at a second control device, the first command input signal from the controller when the controller is in the failure mode, the second control device generating a second control signal representative of the steering input and transmitting the second control signal to the second actuator;

wherein the second actuator exerts a first force on the first wheel in a first direction;

receiving, at a third control device, the first command input signal from the controller when the controller is in the failure mode, the third control device generating a third control signal representative of the steering input and transmitting the third control signal to the third actuator;

wherein the third actuator exerts a second force on the second wheel in a second direction.

11. The method of claim 10, further comprising configuring the controller to be in one of the first operational mode or the second operational mode, wherein the first operational mode is a normal operational mode and the second operational mode is a failure mode.

12. The method of claim 10, wherein the first control device is a steering control device, the second control device is a braking control device, and the third control device is a drivetrain control device.

13. The method of claim 10, wherein the first force and the second force alter a direction of the vehicle.

14. The method of claim 10, wherein the first force removes energy from the vehicle and the second force adds energy to the vehicle.

15. A steer-by-wire system for a vehicle, the system comprising:

a controller configured to alter a direction of the vehicle during a steer-by-wire failure, the controller configured to

operate in either a first operational mode or a failure mode,

determine whether a plurality of control devices are functioning properly and to send command input signals,

operate in the failure mode if one or more of the plurality of control devices are functioning improperly, and, while in the failure mode, send command input signals only to those control devices that are functioning properly to control and monitor those control devices;

a steering device coupled to a detector, the detector configured to detect a steering input from a driver and output a signal representative of a steering input;

a first actuator coupled to a first control device, the first control device configured to generate a first control signal representative of the steering input when it receive a first command input signal from the controller and the controller is in a failure mode;

wherein the first actuator alters a direction of the vehicle by removing energy from the vehicle; and

a second actuator coupled to a second control device, the second control device configured to generate a second control signal representative of the steering input when it receive a first command input signal from the controller and the controller is in the failure mode;

wherein the second actuator alters the direction of the vehicle by adding energy to the vehicle.

16. The system of claim 15, wherein the controller is configured to be in one of a first operational mode or the failure mode.

17. The system of claim 15, wherein the controller is coupled to the first control device and the second control device.

18. The system of claim 15, wherein the first mechanical output exerts a braking force and the second mechanical output exerts a torque.

19. The system of claim 15, wherein the steering device is a steering wheel.

20. The system of claim 15, wherein the direction of the vehicle is altered during a control response time interval.

21. The system of claim 20, wherein the control response time interval is altered by adding energy to or removing energy from the vehicle at different rates.