Machine fluid sensor and method

• US 20040099050A1
• Filed: 06/02/2003
• Published: 05/27/2004
• Est. Priority Date: 10/18/2002
• Status: Active Grant

• Current Assignee: Meas France
• Original Assignee: Symyx Technologies Incorporated (Dassault Systemes SA)
• Inventors: Bennett, James, Spitkovsky, Mikhail, Pinkas, Daniel M., Matsiev, Leonid, Kolosov, Oleg
• Granted Patent: US 7,043,969 B2
• Time in Patent Office: Days
• US Class Current: 73/61.45
• CPC Class Codes: F02D 2200/0611 Fuel type, fuel composition or fuel quality
• CPC Class Codes: F02D 2250/11 Oil dilution, i.e. prevention thereof or special controls according thereto
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: G01F 23/2966 making use of acoustical resonance or standing waves
• CPC Class Codes: G01N 11/16 by measuring damping effect upon oscillatory body
• CPC Class Codes: G01N 2291/014 Resonance or resonant frequency
• CPC Class Codes: G01N 2291/0226 Oils, e.g. engine oils
• CPC Class Codes: G01N 2291/02416 Solids in liquids
• CPC Class Codes: G01N 2291/02818 Density, viscosity
• CPC Class Codes: G01N 2291/02836 Flow rate, liquid level
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0423 Surface waves, e.g. Rayleigh waves, Love waves
• CPC Class Codes: G01N 2291/0426 Bulk waves, e.g. quartz crystal microbalance, torsional waves
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 29/022 Fluid sensors based on microsensors, e.g. quartz crystal-microbalance [QCM], surface acoustic wave [SAW] devices, tuning forks, cantilevers, flexural plate wave [FPW] devices microdevices per se B81B
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: G01N 29/30 Arrangements for calibrating or comparing, e.g. with standard objects
• CPC Class Codes: G01N 29/348 with frequency characteristics, e.g. single frequency signals, chirp signals measuring frequency of mechanical vibrations or acoustic waves in general G01H1/06, G01H3/04; measuring frequency or analysing frequency spectra G01R23/00
• CPC Class Codes: G01N 9/002 using variation of the resonant frequency of an element vibrating in contact with the material submitted to analysis G01N9/34 takes precedence

Abstract

A method for analyzing a fluid contained within a machine, comprising the steps of providing a machine including a passage for containing a fluid; placing a sensor including a mechanical resonator in the passage; operating the resonator to have a portion thereof translate through the fluid; and monitoring the response of the resonator to the fluid in the passage. A preferred sensor includes a tuning fork resonator.

Claims

1. A method for analyzing a fluid contained within a machine, comprising the steps of:

a) providing an machine including a passage for containing a fluid;

b) placing a sensor including a mechanical resonator in the passage;

c) operating the resonator to have a portion thereof translate through the fluid; and

d) monitoring the response of the resonator to the fluid in the passage.

2. The method of claim 1 wherein said monitoring step (d) includes monitoring the change of frequency of the mechanical resonator while maintaining the input signal to the resonator as a constant.

3. The method of claim 1, wherein said monitoring step (d) includes monitoring the change in electrical feedback from the resonator while maintaining a constant frequency.

4. The method of claim 1, wherein said input signal is a variable frequency input signal.

5. The method of claim 1, wherein said monitoring step (d) includes varying the frequency of a variable frequency input signal over a predetermined frequency range to obtain a frequency-dependent resonator response of the mechanical resonator.

6. The method of claim 1, wherein the resonator is a tuning fork resonator.

7. The method of claim 6, wherein the resonator is located in a temperature controlled region.

8. The method of claim 1, wherein said resonator is selected from the group consisting of selected from tuning forks, cantilevers, bimorphs, and unimorphs.

9. The method of claim 1, wherein said sensor is a mechanical transducer operated in a non-resonant mode wherein at least a portion of the mechanical transducer is translated through said fluid allowing the response to be related to mechanical impedance.

10. The method of claim 1, wherein the response is at least related to the viscosity of the fluid.

11. A method for analyzing a circulating fluid of an automotive vehicle, comprising the steps of:

a) providing an automotive vehicle component including a passage for a fluid;

b) placing a sensor including a mechanical resonator in the passage;

c) applying an input signal to the resonator for operating the resonator at a frequency of less than about 100 kHz; and

d) monitoring the response of the resonator to the fluid in the passage.

12. The method of claim 11, further comprising outputting a signal upon detection by the sensor of the absence of the fluid.

13. The method of claim 11, further comprising outputting a signal upon detection by the sensor of a contaminant.

14. The method of claim 11, further comprising outputting a signal upon detection by the sensor of a temperature of the fluid.

15. The method of claim 14, further comprising determining viscosity as a function of temperature.

16. The method of claim 11, wherein the response of the resonator is indicative of dielectric properties of the fluid.

17. The method of claim 11, wherein the monitoring step occurs at a temperature below −

40°

C.

18. The method of claim 11, wherein the monitoring step occurs at a temperature above 125°

C.

19. The method of claim 11, wherein the response is compared against a known reference value for the fluid.

20. The method of claim 19, wherein the reference value is obtained by determining the value of the fluid substantially contemporaneously with the initial introduction of the fluid in the passage.

21. The method of claim 11, further comprising outputting a signal to an on board diagnostic device equipped in the vehicle.

22. The method of claim 11, further comprising outputting a signal to a telemetry device external of the vehicle.

23. The method of claim 11, further comprising outputting a signal to an engine control unit.

24. The method of claim 23, further comprising varying a function of an automotive vehicle engine in response to the signal to the engine control unit.

25. The method of claim 11, wherein the resonator operates substantially free of generation of acoustic waves in the oil.

26. The method of claim 11, wherein the resonator includes a coating layer over at least a portion of its outer surface.

27. The method of claim 11, wherein the resonator is a tuning fork that is located in a temperature controlled region.

28. The method of claim 11, wherein said sensor is a mechanical transducer operated in a non-resonant mode wherein at least a portion of the mechanical transducer is translated through said fluid while allowing the response to be related to mechanical impedance.

29. The method of claim 11, wherein the response is at least related to the viscosity of the fluid.

30. A method for analyzing a circulating oil of an automotive vehicle engine, comprising the steps of:

a) providing an automotive vehicle engine including an engine oil passage;

b) placing a sensor including a tuning fork resonator in the passage;

c) applying an input signal to the resonator for operating the resonator at a frequency of less than about 100 kHz; and

d) monitoring the response of the resonator to the oil in the passage.

31. The method of claim 30, wherein the input signal is a varying frequency input signal.

32. The method of claim 31, wherein the tuning fork resonator operates substantially free of generation of acoustic waves in the oil.

33. The method of claim 32, wherein the tuning fork resonator includes a coating layer over at least a portion of its outer surface.

34. The method of claim 33, wherein the coating layer is formed of PTFE.

35. The method of claim 33, wherein the coating layer includes multiple layers.

36. The method of claim 33, wherein the coating layer is made from a ceramic material.

37. The method of claim 30, wherein the monitoring step is performed continuously during operation of the engine.

38. The method of claim 30, wherein the monitoring step is performed intermittently during operation of the engine.

39. The method of claim 30, wherein the sensor is located in an engine oil pan.

40. The method of claim 30, further comprising a second tuning fork resonator.

41. The method of claim 30, wherein the resonator is located in a temperature controlled region.

42. The method of claim 30, wherein said sensor is a mechanical transducer operated in a non-resonant mode wherein at least a portion of the mechanical transducer is translated through said fluid while such that the response may be related to mechanical impedance.

43. The method of claim 30, wherein the response is at least related to the viscosity of the fluid.

44. A sensor for a fluid, comprising:

a. at least one resonator exhibiting a characteristic selected from;

i. a coating placed upon the resonator in a thickness greater than about 0.1 micron will not substantially detract from resonance performance;

ii. the resonator is operable and is operated at a frequency of less than about 1 MHz;

iii. the resonator is substantially resistant to contaminants proximate to the sensor surface;

iv. the resonator operates to displace at least a portion of its body through a fluid;

v. the resonator responses are capable of de-convolution for measuring one or more individual properties of density, viscosity, or dielectric constant;

or

vi. combinations of characteristics (i)-(v); and

b. at least one connector for signally connecting the resonator with a source of a variable frequency input signal and a device for monitoring the response of the resonator to the signal.

45. The sensor of claim 44, wherein the resonator is coated over at least a portion of its surface.

46. The sensor of claim 44, wherein the resonator is made of quartz, lithium, niobate, zinc oxide, lead zirconate titanate (PZT) or a mixture thereof.

47. The sensor of claim 46, wherein the coating is made of a hydrophobic material.

48. The sensor of claim 45, wherein the resonator is made of quartz, lithium, niobate, zinc oxide, lead zirconate titanate (PZT) or a mixture thereof.

49. The sensor of claim 47, wherein the resonator is made of quartz, lithium, niobate, zinc oxide, lead zirconate titanate (PZT) or a mixture thereof.

50. The sensor of claim 49, wherein the connector is made of a plastic material.

51. The sensor of claim 50, wherein the plastic material is a polyamide.

52. The sensor of claim 44, wherein the resonator is a tuning fork.

53. The sensor of claim 52, wherein the resonator is located in a temperature controlled region.