APPARATUS FOR DETECTING FRICTION IN A POWER STEERING SYSTEM

• US 20140121884A1
• Filed: 10/29/2013
• Published: 05/01/2014
• Est. Priority Date: 10/29/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Engels, Frank Peter
• Granted Patent: US 10,479,401 B2
• Time in Patent Office: Days
• US Class Current: 701/29.2
• CPC Class Codes: B62D 5/0481 monitoring the steering system, e.g. failures
• CPC Class Codes: B62D 5/0496 by using a temperature sensor

Abstract

A power steering system including a sensor arranged or located in the steering system. The sensor detects an acoustic vibration or an acceleration signal in the steering system during a change in the steering angle and generates a sensor signal representing the vibration or the acceleration signal. A control unit receives the sensor signal and compares the sensor signal with a threshold value to detect a fault state; for example when the sensor signal is larger than the threshold value.

Claims

1. A steering system comprising:

a steering gear;

a sensor operative detect an acoustic vibration and/or an acceleration signal of the steering system during a change in the steering angle and to generate a sensor signal which represents the vibration and/or acceleration; and

a control unit operative to compare the sensor signal with a threshold value and to detect a fault state if the sensor signal is larger than the threshold value.

2. A steering system as set forth in claim 1 wherein said sensor is selected from a group consisting of an acceleration sensor, a torque sensor, a position sensor and a power consumption sensor.

3. A steering system as set forth in claim 1 wherein said sensor an acceleration sensor.

4. A steering system as set forth in claim 1 wherein said sensor an acoustic sensor.

5. A steering system as set forth in claim 3 wherein said acceleration sensor is an acceleration sensor of an airbag triggering system.

6. A steering system as set forth in claim 1 wherein said sensor is integrated into said control unit.

7. A steering system as set forth in claim 1 including a ball screw;

and

said sensor is arranged on the ball screw.

8. A steering system as set forth in claim 1 wherein the threshold value is an amplitude value;

and

said control unit operative to compare a maximum modulation of a sensor signal with said amplitude value.

9. A steering system as set forth in claim 1 wherein said control unit transmits a fault state to a human/machine interface.

10. A steering system as set forth in claim 1 including an electric auxiliary motor;

and

said control unit operative to deactivate said electric auxiliary motor upon detection of a fault state.

11. A steering system as set forth in claim 1 including a filter unit, said filter unit connected between said sensor and said control unit wherein said filter unit filters a sensor signal.

12. A steering system as set forth in claim 11 wherein said filter unit is suppresses frequency components of said sensor signal above an upper cutoff frequency.

13. A steering system comprising:

a steering gear;

a ball screw;

a sensor operative to detect an acceleration signal of the steering system during a change in the steering angle and to generate a sensor signal;

a control unit operative to compare the sensor signal with a threshold value and to detect a fault state if the sensor signal is larger than the threshold value;

an electric auxiliary motor connected to steering gear; and

said control unit operative to deactivate said electric auxiliary motor upon detection of a fault state.

14. A steering system as set forth in claim 13 including a filter unit, said filter unit connected between said sensor and said control unit wherein said filter unit filters a sensor signal.

15. A steering system as set forth in claim 14 wherein said filter unit is suppresses frequency components of said sensor signal above an upper cutoff frequency.

16. A steering system as set forth in claim 13 wherein the threshold value is an amplitude value;

and

said control unit operative to compare a maximum modulation of a sensor signal with said amplitude value.