Universal sensor interface system and method

• US 6,115,654 A
• Filed: 12/23/1997
• Issued: 09/05/2000
• Est. Priority Date: 12/23/1997
• Status: Expired due to Term

• Current Assignee: Simmonds Precision Products, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Simmonds Precision Products, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Eid, Bradley Franz, Durkee, Scott Robert, Darwin, Keith Patrick
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US08/997,271
• Time in Patent Office: 987 Days
• Field of Search: 701/34, 701/29, 701/35, 342/385, 280/735, 340/945, 244/1
• US Class Current: 701/34
• CPC Class Codes: G01D 21/02 Measuring two or more variables by means not covered by a single other subclass

Abstract

A universal sensor interface system that utilizes a common hardware and software interface to drive many types of sensors. A variety of stimulation signals are generated that are transmitted to a plurality of sensors. The stimulation signals cause the sensors to generate response signals in the form of parametric measurements, which are then converted into a common format. The sensor response signals are processed and output as usable inputs to a data consuming apparatus. A method of automatically determining the sensor configuration in an aircraft sensor system is also provided. During operation the host computer system or digital signal processor is programmed to analyze sensor response signals to detect sensor faults, help predict sensor failures, and determine if there has been a sensor error. The universal sensor interface system is also capable of notifying a system operator of wiring problems with a particular sensor or if a particular sensor is malfunctioning.

Claims

1. A method of automatically determining the sensor configuration in an aircraft sensor system, comprising the steps of:

sending a plurality of initialization signals to a digital signal processor;

converting said initialization signals into a plurality of predetermined sensor check signals with said digital signal processor;

driving a plurality of sensor units with said sensor check signal;

receiving a response signal from each of said sensor units;

comparing each of said response signals with a pre-selected database of sensor responses; and

selecting the appropriate sensor based on said comparison.

2. The method of claim 1, wherein said pre-selected database of sensor responses are stored in a look-up table.

3. The method of claim 1, further comprising the step of using a plurality of serial ports to communicate with said digital signal processor.

4. A method of automatically recognizing sensors for a universal sensor interface, comprising the steps of:

generating an arbitrary waveform to power a plurality of sensor units;

acquiring a plurality of sensor response signals from said sensor units;

converting said acquired sensor response signals into a parametric measurement;

receiving said parametric measurement; and

selecting an appropriate sensor type based on a comparison of said parametric measurement.

5. The method of claim 4, further comprising the step of using a look up table to determine the appropriate sensor type.

6. The method of claim 4, wherein said means for generating an arbitrary waveform is controlled by an embedded computer system.

7. The method of claim 4, further comprising the step of analyzing said parametric measurement in order to determine if there has been a sensor error.

8. The method of claim 4, further comprising the step of locating a faulty sensor by analyzing said parametric measurement.

9. A method of initializing a universal sensor interface, comprising the steps of:

generating a plurality of arbitrary initialization signals;

outputting said arbitrary initialization signals to a digital processor;

transforming said arbitrary initialization signals into analog sensor stimulation signals to drive a plurality of sensors;

directing said sensor stimulation signals to said plurality of sensors;

receiving a plurality of initialization response signals from said plurality of sensors at said digital processor;

communicating said sensor response signals from said digital processor; and

interpreting said initialization response signals according to a predetermined set of sensor responses.

10. The method of claim 9, further comprising the step of using a look up table to interpret said initialization response signals.

11. The method of claim 9, further comprising the step of detecting a faulty initialization response signal.

12. The method of claim 9, further comprising the step of detecting a wiring problem.

13. The method of claim 9, further comprising the step of detecting a malfunctioning sensor.

14. The method of claim 9, further comprising the step of detecting that pin connector assignments must be reconfigured for a sensor.

15. The method of claim 9, further comprising the step of detecting the location and cause of a particular sensor fault.

16. A universal sensor interface system for an aircraft measurement and control system, comprising:

a central processing unit;

a standard interface unit connected with said central processing unit for communicating system information to said aircraft measurement and control units;

a first communication port coupled with said central processing unit;

a digital signal processing unit having a second communication port coupled with said first communication port on said central processing unit for transferring data between said central processing unit and said digital signal processing unit; and

a mixed signal unit in communication with said digital signal processor and a plurality of sensors for generating stimulation signals and receiving response signals from said plurality of sensors.

17. The universal sensor interface system for an aircraft measurement and control system of claim 16, wherein said central processing unit further comprises a microprocessor.

18. The universal sensor interface system for an aircraft measurement and control system of claim 16, wherein said first and second communication ports further comprise serial ports.

19. The universal sensor interface system for an aircraft measurement and control system of claim 16, wherein said plurality of sensors have output signals in communication with the input of a second multiplexer.

20. The universal sensor interface system for an aircraft measurement and control system of claim 19, wherein said second multiplexer is coupled with the input of an analog to digital converter.

21. The universal sensor interface system for an aircraft measurement and control system of claim 20, wherein said analog to digital converter has an input coupled with said digital signal processor for communicating the sensor response signal to said digital signal processor.

22. The universal sensor interface system for an aircraft measurement and control system of claim 16, wherein said mixed signal generation unit further comprises a digital to analog converter coupled with said digital signal processor.

23. The universal sensor interface system for an aircraft measurement and control system of claim 22, wherein said digital to analog converter is in communication with a current signal generation unit.

24. The universal sensor interface system for an aircraft measurement and control system of claim 22, wherein said current signal generation unit is coupled with an input on said first multiplexer.

25. The universal sensor interface system for an aircraft measurement and control system of claim 22, wherein said digital to analog converter is in communication with a voltage signal generation unit.

26. The universal sensor interface system for an aircraft measurement and control system of claim 25, wherein said voltage signal generation unit is coupled with an input on a first multiplexer.

27. The universal sensor interface system for an aircraft measurement and control system of claim 26, wherein said first multiplexer has an output coupled with a sensor selection unit for selectively driving a chosen sensor.

28. The universal sensor interface system for an aircraft measurement and control system of claim 26, wherein said first multiplexer has an output coupled with a signal reference unit for calibrating the sensor response signals.

29. The universal sensor interface system for an aircraft measurement and control system of claim 28, wherein said signal reference unit has an output signal coupled with the input of said second multiplexer.

30. A method of providing a universal sensor interface to an aircraft comprising the steps of:

stimulating a plurality of sensors with a means for selectively driving said sensors with an analog stimulation signal, said sensors being capable of generating aircraft system signals,

controlling said sensors with said stimulation signal generated by a digital processor,

sensing said aircraft system signal with an input port of said digital processor,

converting said aircraft system signals into parametric outputs; and

providing said parametric outputs in a standard format for consumption by other devices.

31. The method of claim 30, further comprising the step of communicating between said digital processor and said other devices through a plurality of serial ports.

32. The method of claim 30, further comprising the step of sending said aircraft system signals to said digital processor with a means connected with the outputs of said sensors for collecting a plurality of sensor response signals and converting them to a digital signal.

40. The universal sensor interface of claim 30 wherein said digital processor comprises a processor from the group consisting of a micro-processor and a digital signal processor.

41. The universal sensor interface of claim 40 further comprising a first multiplexer coupled with the output of said at least one digital to analog converter for directing said stimulation signal to a predetermined sensor.

42. The universal sensor interface of claim 40 further comprising a voltage controlled current source connected with the output of said at least one digital to analog converter.

43. The universal sensor interface of claim 41 wherein the output channels of said multiplexer is coupled with at least one current/voltage multiplexer.

44. The universal sensor interface of claim 42 wherein an output port of said voltage controlled current source is connected with said at least one current/voltage multiplexer.

45. The universal sensor interface of claim 44 wherein said plurality of sensors have input channels connected with the output port of said current/voltage multiplexer.

33. A universal sensor interface, comprising:

means for generating a plurality of different stimulation signals to drive a plurality of sensors of different types;

said generating means including a digital processor having an output coupled to at least one digital to analog converter for selectively driving each sensor of said plurality with an analog stimulation signal based on the sensor type thereof;

means coupled to said plurality of sensors for accepting a plurality of sensor response signals and converting said sensor response signals into parametric measurements having a common format; and

means coupled to said means for accepting sensor response signals for outputting said parametric measurements as useable inputs to a sensor data consuming apparatus.

34. The universal sensor interface of claim 33 further comprising means for automatically recognizing sensor types based upon analyzing sensor response signals from said sensors in response to a predetermination stimulation signal.

35. The universal sensor interface of claim 33 further comprising means for analyzing sensor response signals.

36. The universal sensor interface of claim 35 wherein said means for analyzing sensor response signals is operable to detect sensor faults.

37. The universal sensor interface of claim 35 wherein said means for analyzing sensor response signals is operable to predict sensor failures.

38. The universal sensor interface of claim 33 comprising an input multiplexer connected with the output channels of said plurality of sensors.

39. The universal sensor interface of claim 38 further comprising an analog to digital converter connected with said input multiplexer for supplying sensor response signals to said digital processor.

46. The universal sensor interface of claim 33 including means for communicating said output signals to a host computer system in an aircraft;

a sensor unit coupled to said means for generating a stimulation signal for sensing aircraft operating parameters and generating an aircraft operating signal; and

an analog to digital converter coupled to receive said aircraft operating signals and transform said analog aircraft operating signals to a digital signal for said digital processor.

47. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one accelerometer.

48. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one pressure transducer.

49. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one point level.

50. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one resistance temperature detector.

51. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one DC capacitance probe.

52. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one vibrating-spool densitometers.

53. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one AC capacitance probe.

54. The universal sensor interface of claim 46, wherein said sensor unit comprises at least one ultrasonic fuel transducer.