Control system which carries out the model-supported safety monitoring of an electronically regulated controller in the motor vehicle

• US 6,803,736 B1
• Filed: 03/05/2002
• Issued: 10/12/2004
• Est. Priority Date: 05/19/1999
• Status: Expired due to Fees

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Kraemer, Wolfgang, Hommel, Mathias
• Primary Examiner(s): Martin, David
• Assistant Examiner(s): SAN MARTIN, EDGARDO
• Application Number:
  US09/979,298
• Time in Patent Office: 952 Days
• Field of Search: 318/567, 318/563, 318/564, 318/565, 318/638, 318/639, 318/650-652, 318/798, 318/799, 318/805, 318/806, 388/800, 388/842, 388/907.5, 388/909, 180/404, 180/443, 180/446, 361/23, 361/30, 361/31, 361/33, 361/54, 361/56, 361/57, 361/78, 361/79, 361/86, 361/87
• US Class Current: 318/567
• CPC Class Codes: G05B 9/02 electric
• CPC Class Codes: Y10S 388/909 Monitoring means

Abstract

A system for controlling a regulator equipped with an electric servomotor in a motor vehicle. With reference to an example of an electronic steering system that has an electric-motor steering regulator, output parameters are generated by a model-assisted monitor for evaluating the suitability of a correction for the regulator, and thus criteria for a possible shutdown or to initiate emergency action, as a function of setpoint parameters for the electric servomotor, of instantaneous parameters measured by individual sensors, and of the driving state, and, based on a setpoint behavior of the regulator and on a model simulating the control sections it contains.

Claims

1. A control system for use in a motor vehicle, said motor vehicle including an actuator regulator and an electric servomotor, said control system comprising:

a current regulator which determines a correct current parameter value on the basis of comparing a setpoint value which is determined from an operating state of the motor vehicle and which corresponds to a desired set position, and an instantaneous value which corresponds to an instantaneous set position of the actuator regulator;

a model assisted monitor which generates an output evaluating parameter value for evaluating the suitability of correcting the actuator regulator as a function of servomotor setpoint parameters, a plurality of instantaneous parameters measured by a plurality of sensors, and the current operating state of the vehicle, said output evaluating parameter value is based on a model which simulates setpoint behavior of the action regulator, said model-assisted monitor having a load torque estimator which estimates a theoretical load torque as a function of at least one of said plurality of instantaneous parameters which comprise instantaneous position values and the operating state of the vehicle, said model-assisted monitor including a control section control model and a servomotor model, said model-assisted monitor calculates theoretical instantaneous values for the servomotor position, the actual applied servomotor torque, and the instantaneous servomotor current, as a function of the servomotor setpoint parameters and the estimated theoretical load torque, said model-assisted monitor generating a different signal from the calculated theoretical instantaneous values and corresponding actual instantaneous values, whereby suitability of correcting the actuator regulator can be evaluated.

2. Control system pursuant to claim 1 wherein said model-assisted monitor compares the estimated theoretical load torque with the actual applied servomotor torque, which is calculated by means of a motor model of the servomotor as a function of a measured instantaneous value of motor current and of an instantaneous motor position measured by a corresponding position sensor, said model-assisted monitor generates a torque differential signal from the comparison for evaluating the suitability of the correction.

3. Control system pursuant to claim 2, wherein said model-assisted monitor calculates a theoretical instantaneous current value for the servomotor current as a function of the setpoint current of the servomotor, the instantaneous motor position measured by a corresponding position sensor, and the theoretical load torque, and generates a differential signal between the calculated instantaneous current value and the instantaneous current value measured by a current sensor for evaluating the suitability of the correction.

4. Control system pursuant to claim 3, wherein said model-assisted monitor calculates a theoretical instantaneous position value for the position of the servomotor that should be set in reaction to the setpoint parameter at the servomotor, and generates a differential signal between the calculated theoretical instantaneous position value and the position value measured by a corresponding position sensor for evaluating the suitability of the correction.

5. Control system pursuant to claim 4, wherein said model-assisted monitor includes an error interpreter that receives the torque differential signal, the instantaneous current differential signal, and the position value differential signal as input parameters and generates therefrom safety-relevant error and failure signals.

6. Control system pursuant to claim 5, wherein the error interpreter decides on the validity of the instantaneous current differential signal and the instantaneous position value differential signal as a function at least of the torque differential signal.

7. Control system pursuant to claim 1, wherein the electric servomotor is a permanent magnet d.c. motor.

8. Control system pursuant to claim 1, wherein the electric servomotor is an electronically commutated motor.

9. Control system pursuant to claim 1, wherein the electric servomotor is a three-phase asynchronous motor.

10. Control system pursuant to claim 1, wherein the electric servomotor is a piezoelectric motor.

11. Control system pursuant to claim 1, wherein the electric an asynchronous motor.

12. The control system pursuant to claim 1, and further including an electronic steering system that has an electronic steering servomotor, which superimposes an additional steering angle on a steering wheel angle given by a driver to a steering wheel for one of each of a left and right wheel, and two wheels linked together, and wherein the model-assisted monitor provides signals for the safety monitoring of the steering system.

13. The control system pursuant to claim 12, wherein the steering system is set up for individually steering a left wheel and a right wheel.

14. The control system pursuant to claim 12, wherein the steering system is set up to steer two wheels connected by a tie rod.

15. The control system pursuant to claim 13, including a safety monitor which initiates one of the safety measures from the group consisting of activating an error indicator, sounding a warning signal, initiating emergency action, and shutting down the electronic steering system.

16. The control system pursuant to claim 1, including an electronic sway stabilization system that has at least one electric sway stabilizing motor.

17. The control system pursuant to claim 1, including an electronic brake system that has at least one electric brake servomotor.

18. The control system pursuant to claim 1, including an steering wheel simulator for steer-by-wire steering wherein a counter-torque dependent on the state of the vehicle is generated as a function of the driver'"'"'s steering desires.