Sensor for measuring physical variables and for passing on the measured variable, circuit having such a sensor and method for operating the sensor and the circuit

• US 7,576,643 B2
• Filed: 09/13/2006
• Issued: 08/18/2009
• Est. Priority Date: 03/13/2004
• Status: Expired due to Fees

• Current Assignee: Hella KGaA Hueck & Company, Robert Bosch GmbH
• Original Assignee: Hella KGaA Hueck & Company, Robert Bosch GmbH
• Inventors: Bartscht, Manfred, Schweinfurth, Reiner, Irle, Henning, Meiwes, Johannes
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US11/520,381
• Publication Number:
  US 20070076336A1
• Time in Patent Office: 1,070 Days
• Field of Search: 340/506, 340/511, 340/538, 340/517, 340/521, 324/537, 324/236, 324/538, 324/555
• US Class Current: 340/538
• CPC Class Codes: G05B 9/03 with multiple-channel loop, i.e. redundant control systems

Abstract

A sensor for measuring a variable, in particular a physical variable, includes at least one converter element converting the variable into an electrical signal. At least one electronic signal processing unit conditions and/or processes the electrical signal to provide a sensor signal. The at least one electronic signal processing unit has at least one diagnosis device. An interface passes on the sensor signal through a connection, in particular a cable connection, to an electrical device, in particular a control device. The diagnosis device causes a fault signal instead of the sensor signal to be present at the interface when a fault occurs, for clearly distinguishing a fault at the interface from a processing fault. A circuit having such a sensor and a method for operating the sensor and the circuit are also provided.

Claims

1. A sensor for measuring a variable, the sensor comprising:

at least one converter element converting the variable into an electrical signal;

at least one electronic signal processing unit for at least one of conditioning or processing the electrical signal to provide a sensor signal, said at least one electronic signal processing unit having at least one diagnosis device; and

an interface for passing on the sensor signal through a connection to an electrical device;

said diagnosis device causing a fault signal instead of the sensor signal to be present at said interface when a fault occurs, for clearly distinguishing a fault at said interface from a processing fault.

2. The sensor according to claim 1, wherein the variable is a physical variable.

3. The sensor according to claim 1, wherein the electrical device is a control device.

4. The sensor according to claim 1, wherein the connection is a cable connection.

5. The sensor according to claim 1, wherein the fault signal is a fixed potential which is otherwise not used functionally.

6. The sensor according to claim 5, wherein the fault signal is a predetermined fixed potential.

7. The sensor according to claim 1, wherein the fault signal is a sequence of different electrical potentials.

8. The sensor according to claim 1, wherein the fault signal is a predetermined sequence of different electrical potentials.

9. The sensor according to claim 1, wherein the fault signal is a repetitive pattern of electrical potentials.

10. The sensor according to claim 1, wherein the fault signal contains information on the nature of the fault.

11. The sensor according to claim 1, wherein the fault signal is a continuous change in minimum and maximum potentials.

12. A circuit, comprising:

at least two sensors, at least one of said sensors being a sensor according to claim 1.

13. The circuit according to claim 12, wherein said sensors measure the same electrical variable.

14. The circuit according to claim 13, wherein at least one of said sensors includes a device for monitoring synchronism of said sensors.

15. The circuit according to claim 14, wherein said sensor having said synchronism monitoring device is a sensor according to claim 1.

16. The circuit according to claim 15, wherein said synchronism monitoring device indicates a deviation of at least one of the electrical signal or the sensor signal of said at least two sensors to said diagnosis device as a fault.

17. A method for operating a sensor, the method comprising the following steps:

providing a sensor for measuring a variable, the sensor including;

at least one converter element converting the variable into an electrical signal;

at least one electronic signal processing unit for at least one of conditioning or processing the electrical signal to provide a sensor signal, said at least one electronic signal processing unit having at least one diagnosis device;

an interface for passing on the sensor signal through a connection to an electrical device; and

said diagnosis device causing a fault signal instead of the sensor signal to be present at said interface when a fault occurs, for clearly distinguishing a fault at said interface from a processing fault;

operating the sensor;

during fault-free operation, by converting the variable to be measured into an electrical signal with the converter element and at least one of conditioning the electrical signal or processing the electrical signal with the electronic circuit to provide the sensor signal to be tapped off at the interface; and

during faulty operation, by detecting at least one of an occurrence or a nature of the fault and producing a fault signal with the diagnosis device, to be tapped off instead of the sensor signal at the interface.

18. A method for operating a circuit, which comprises the following step:

operating at least a first one of at least two sensors according to claim 17.

19. The method according to claim 18, which further comprises monitoring synchronism of the at least two sensors with the first sensor and, in the event of a deviation of at least one of the electrical signal or the sensor signal, indicating the fault signal at the interface.

20. A method for operating a sensor, the method comprising the following steps:

during fault-free operation, converting a variable to be measured into an electrical signal with a converter element and at least one of conditioning the electrical signal or processing the electrical signal with an electronic circuit to provide a sensor signal to be tapped off at an interface; and

during faulty operation, detecting at least one of an occurrence or a nature of a fault and producing a fault signal with a diagnosis device, to be tapped off instead of the sensor signal at the interface.