Method for operating a sensor in a safety system

• US 7,539,569 B2
• Filed: 06/09/2006
• Issued: 05/26/2009
• Est. Priority Date: 12/10/2003
• Status: Active Grant

• Current Assignee: Bayerische Motoren Werke AG
• Original Assignee: Bayerische Motoren Werke AG
• Inventors: Neuberger, Ralph, Baur, Richard, Lu, Yan
• Primary Examiner(s): Tran; Dalena
• Application Number:
  US11/449,590
• Publication Number:
  US 20060229785A1
• Time in Patent Office: 1,082 Days
• Field of Search: 701 45- 47, 735/78, 735/79, 73581-584, 73587-589, 735/95, 381/150, 381/353, 381173-178, 381/190, 381/191, 700/280
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/01068 between different sensors and airbag control unit
• CPC Class Codes: B60R 2021/01184 Fault detection or diagnostic circuits in power circuits B60R2021/01129
• CPC Class Codes: B60R 2021/01302 monitoring vehicle body vibrations or noise
• CPC Class Codes: B60R 21/01 Electrical circuits for triggering passive safety arrangements, e.g. airbags, safety belt tighteners, in case of vehicle accidents or impending vehicle accidents electrical circuits for transmission of signals between steering wheel and the vehicle itself B60R16/027; for electrically actuating belt retractor locking means B60R22/343
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: G05B 9/02 electric

Abstract

In a safety system and a method of operating a sensor in a safety system, the sensor transmits an electric reaction signal to a central system unit, and is also excited by the central system unit by a diagnostic and/or excitation signal as a reversible electro-mechanical system.

Claims

1. A method of operating a sensor in a mechanical system, said method comprising:

in a test excitation, a central control unit exciting the sensor by an electrical excitation signal, as a reciprocal electro-mechanical operating system, causing said sensor to generate mechanical vibrations in said system; and

after said test excitation, the sensor transmitting to the central control unit an electric reaction signal that is indicative of residual vibrational behavior of said system, from the mechanical vibrations that were generated by the sensor in the test excitation;

wherein the sensor includes a single reciprocal electro-mechanical element which both receives and reacts to the electrical excitation signal for generating said mechanical vibrations, and generates the electrical reaction signal.

2. The method according to claim 1, wherein

the sensor is excited to generate a testing excitation for one of diagnostic purposes and testing of the sensor itself.

3. The method according to claim 1, wherein

said sensor is included in a network of sensors;

at least one sensor within said network of sensors is excited by an electrical excitation signal; and

electric reaction signals of all sensors are transmitted to the central system unit.

4. The method according to claim 1, wherein

at least one sensor is used for locating a resonance zone and for generating a controlled countervibration.

5. The method according to claim 1, wherein:

control of a phase-shifted vibration is actively generated by the sensor; and

control of the phase shifted vibration is monitored by additional sensors within the network.

6. The method according to claim 1, wherein the central system unit triggers at least one diagnostic or excitation signal, evaluates at least one reaction signal, and controls active vibration of the sensor.

7. The method according to claim 6, wherein the control takes place based on one of a databank and a model.

8. The method according to claim 7, wherein, in the event of an accident, a course and progression of a deformation, and a type and seriousness of the respective accident, are diagnosed based on comparison of data of the databank with the model.

9. The method according to the claim 8, wherein data processed by the central system unit are transmitted to a safety device for initiating coordinated protection strategies by using at least one of an air bag system, a belt-tightening system, and an active engine hood.

10. Apparatus for monitoring or analyzing and preventing vibration damage in a mechanical system, said apparatus comprising:

a sensor having a reciprocal material characteristic; and

a central control unit connected to the sensor for targeted excitation and signal analysis, and further evaluation;

wherein said central control unit is programmed to implement a method including,

in a test excitation, the central control unit exciting the sensor by an electrical excitation signal, as a reciprocal electro-mechanical operating system, causing said sensor to generate mechanical vibrations in said system; and

after said test excitation, the sensor transmitting to the central system unit an electric reaction signal that is indicative of residual vibrational behavior of said system from the mechanical vibrations that were generated by the sensor in the test excitation; and

wherein, the sensor includes a single reciprocal electro-mechanical element which both receives and reacts to the electrical excitation signal for generating said mechanical vibrations, and generates the electrical reaction signal.

11. The apparatus according to claim 10, wherein:

said sensor is included in a network of sensors which are arranged in a distributed manner over a monitoring area and are each connected with the central system unit by way of their own separate signal lines and return lines.

12. The apparatus according to claim 10, wherein the central system unit is connected with one of a coordinated model of the monitoring area and a databank.

13. The apparatus according to claim 10, wherein said sensor is included in a network of sensors, which are combined into groups.

14. The apparatus according to claim 13, wherein the sensors are arranged in or on a flexible foil as a carrier.

15. The apparatus according to claim 14, wherein signal lines and return lines are arranged as signal lines for each sensor in or on the flexible foil, as a carrier of the sensors.

16. The apparatus according to claim 15, wherein correspondingly mutually insulated signal lines for electric contacting of the respective sensors are provided in a foil layer of the flexible foil.

17. The apparatus according to claim 16, wherein a piezo-electric plastic foil is provided as a sensor.

18. A method of operating a sensor in a mechanical system which includes mechanical components, said method comprising:

providing in said system a sensor in the form of an electromechanical element which is operable as both an actuator for generating mechanical vibrations in response to an electrical excitation signal, and a sensor for receiving mechanical vibrations and generating electrical signals indicative thereof;

in a test excitation, stimulating said electromechanical element with an electrical excitation signal, such that it generates mechanical vibrations in said system;

after said test excitation, said electromechanical element receiving and generating electrical signals indicative of, residual vibrational behavior of said system resulting from said mechanical vibrations that were generated by the electromechanical element in the test excitation;

evaluating a state of said system based on said electrical signals generated by said electromechanical element and on stored characteristic signals.

19. The method according to claim 18, wherein said evaluating step comprises evaluating an operational status of said electromechanical element.

20. The method according to claim 18, wherein said evaluating step comprises evaluation of said mechanical components in said system.

21. A method for operating a transducer for detecting vibrations in a mechanical system, said method comprising:

in a test excitation, operating the transducer as an actuator to generate vibrations in said mechanical system;

thereafter, operating the transducer as a sensor to detect residual vibrations in said system, and to generate electrical signals indicative of said residual vibrations;

analyzing said electrical signals to evaluate the status of said transducer.