Systems and methods for driver intervention in an automatic steering system

• US 8,930,079 B2
• Filed: 10/22/2009
• Issued: 01/06/2015
• Est. Priority Date: 10/22/2009
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Lee, Yong H., Ryu, Jihan, Deng, Weiwen
• Primary Examiner(s): Algahaim, Helal A
• Assistant Examiner(s): CASTRO, PAUL A
• Application Number:
  US12/604,034
• Publication Number:
  US 20110098890A1
• Time in Patent Office: 1,902 Days
• US Class Current: 701/42
• CPC Class Codes: B62D 1/286 Systems for interrupting non-mechanical steering due to driver intervention

Abstract

A vehicle steering system includes an automatic steering control unit configured to control the vehicle steering system when in an automatic operational state and a driver intervention unit is configured to determine driver intervention during the automatic operational state. The driver intervention unit comprising a decision software module configured to determine driver intervention.

Claims

1. A method, for performance by a tangible device at a vehicle comprising a steering angle sensor, for controlling a vehicle steering system of the vehicle, the method comprising:

receiving, by the tangible device comprising a processor executing instructions stored on a non-transitory computer-readable medium of the tangible device, a measured steering angle obtained by the steering angle sensor of the vehicle;

calculating, by the tangible device executing the instructions stored on a non-transitory computer-readable medium of the tangible device, a moment of inertia, yielding a calculated moment of inertia, according to a relationship amongst factors comprising;

the measured steering angle;

an equivalent damping of the vehicle steering system;

an equivalent stiffness of the vehicle steering system; and

a torque sum, comprising;

a driver-applied steering torque;

an equivalent motor-assist torque; and

an equivalent tire-alignment torque; and

determining, by the tangible device executing the instructions stored on a non-transitory computer-readable medium of the tangible device, during an automatic operational state of the vehicle, as a function of a hands-off moment of inertia and the calculated moment of inertia, whether a driver-intervention condition exists;

wherein;

the relationship is represented by an equation as follows;

2. The method of claim 1, wherein the tangible device comprises the steering angle sensor configured to measure a steering angle, yielding the measured steering angle.

3. The method of claim 2, wherein the tangible device comprises an automatic steering control unit configured to control an electric-power component of the vehicle steering system.

4. The method of claim 2, wherein the tangible device is a part of a driver-intervention unit for use in the vehicle.

5. The method of claim 2, wherein:

J_e is the equivalent moment of inertia of the vehicle steering system;

θ

_s is the measured steering angle;

B_e is the equivalent damping of the vehicle steering system;

K_e is the equivalent stiffness of the vehicle steering system;

Σ

T is the torque summary;

T_d is the driver-applied steering torque;

T_m is the equivalent motor-assist torque;

T_a is the equivalent tire-alignment torque;

an equivalent transfer function, providing a relationship between the measured steering angle (θ

_s) and the equivalent stiffness of the vehicle steering system (K_e), is as follows;

6. A vehicle steering system, for use in a vehicle, comprising:

a processor; and

a computer-readable storage device comprising;

data indicating a hands-off moment of inertia of the vehicle steering system; and

computer-executable instructions that, when executed by the processor, cause the processor to perform operations comprising;

calculating a moment of inertia, yielding a calculated moment of inertia, according to a relationship amongst factors comprising;

a measured steering angle;

an equivalent damping of the vehicle steering system;

an equivalent stiffness of the vehicle steering system; and

a torque sum, comprising;

a driver-applied steering torque;

an equivalent motor-assist torque; and

an equivalent tire-alignment torque; and

determining, during an automatic operational state of the vehicle, as a function of the hands-off moment of inertia and the calculated moment of inertia,

whether a driver-intervention condition exists;

wherein;

the relationship is represented by an equation as follows;

7. The vehicle steering system of claim 6, further comprising an automatic steering control unit configured to control an electric-power component of the vehicle steering system.

8. The vehicle steering system of claim 6, further comprising a steering angle sensor configured to measure a steering angle, yielding the measured steering angle.

9. The vehicle steering system of claim 6, wherein the computer-readable storage device is a part of a driver-intervention unit for use in the vehicle.

10. The vehicle steering system of claim 6, wherein:

J_e is the equivalent moment of inertia of the vehicle steering system;

θ

_s is the measured steering angle;

B_e is the equivalent damping of the vehicle steering system;

K_e is the equivalent stiffness of the vehicle steering system;

Σ

T is the torque summary;

T_d is the driver-applied steering torque;

T_m is the equivalent motor-assist torque;

T_a is the equivalent tire-alignment torque;

an equivalent transfer function, providing a relationship between the measured steering angle (θ

_s) and the equivalent stiffness of the vehicle steering system (K_e), is as follows;

11. A computer-readable storage device comprising computer-executable instructions that, when executed by a processor, cause the processor to perform, in a vehicle steering system, operations comprising:

calculating a moment of inertia, yielding a calculated moment of inertia, according to a relationship amongst factors comprising;

a measured steering angle;

an equivalent damping of the vehicle steering system;

an equivalent stiffness of the vehicle steering system; and

a torque sum, comprising;

a driver-applied steering torque;

an equivalent motor-assist torque; and

an equivalent tire-alignment torque; and

determining, during an automatic operational state of the vehicle, as a function of a hands-off moment of inertia of the vehicle steering system and the calculated moment of inertia, whether a driver-intervention condition exists;

wherein;

the relationship is represented by an equation as follows;

12. The computer-readable storage device of claim 11, wherein the computer-readable storage device is a part of a driver-intervention unit for use in the vehicle.

13. The vehicle steering system of claim 11, wherein:

J_e is the equivalent moment of inertia of the vehicle steering system;

θ

_s is the measured steering angle;

B_e is the equivalent damping of the vehicle steering system;

K_e is the equivalent stiffness of the vehicle steering system;

Σ

T is the torque summary;

T_d is the driver-applied steering torque;

T_m is the equivalent motor-assist torque;

T_a is the equivalent tire-alignment torque;

an equivalent transfer function, providing a relationship between the measured steering angle (θ

_s) and the equivalent stiffness of the vehicle steering system (K_e), is as follows;