Method and apparatus for material identification by means of gravitational field analysis

• US 20060117848A1
• Filed: 03/07/2005
• Published: 06/08/2006
• Est. Priority Date: 12/07/2004
• Status: Active Grant

• Current Assignee: VEGA Grieshaber KG (Grieshaber Verwaltungsgesellschaft mbH)
• Original Assignee: VEGA Grieshaber KG (Grieshaber Verwaltungsgesellschaft mbH)
• Inventors: Raffalt, Felix
• Granted Patent: US 7,240,550 B2
• Time in Patent Office: Days
• US Class Current: 73/313
• CPC Class Codes: G01F 23/00 Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
• CPC Class Codes: G01F 23/0038 using buoyant probes with floats G01F23/30 - G01F23/76
• CPC Class Codes: G01F 23/20 by measurement of weight, e.g. to determine the level of stored liquefied gas
• CPC Class Codes: G01F 23/22 by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water involving the use of floats G01F23/30
• CPC Class Codes: G01F 23/30 by floats
• CPC Class Codes: G01V 7/04 Electric, photoelectric, or magnetic indicating or recording means

Abstract

Described is a sensor for filling level measurement using a gravitational field analysis, comprising a first and a second gravimeter unit. The measurement is effected in a contactless manner, via the container wall and without input of energy into the filling good. Thus, there is no need for a source emitting measurement rays.

Claims

1. Gravimeter unit for determining a gravitational field strength, the gravimeter unit comprising:

a first floating body;

a first detector;

a source for generating a field;

wherein the first floating body is contactlessly holdable in a floating state by a field generated by the source;

wherein a first position of the first floating body is detectable by the first detector;

wherein the gravimeter unit is adapted to determine first data on the basis of the detected first position or the generated field; and

wherein the first data correspond to a first gravitational field strength at a first location.

2. Gravimeter unit according to claim 1,

wherein the field is selected from the group consisting of electric field, magnetic field, electromagnetic field and mechanical flow field.

3. Gravimeter unit according to claim 1,

wherein the first detector is adapted for at least one of capacitive, inductive, conductive and optical detection of the first position of the first floating body.

4. Gravimeter unit according to claim 1,

wherein the source comprises at least one first electrode to generate the electric field;

and

wherein the first detector comprises a second electrode to detect the first position of the first floating body.

5. Gravimeter unit according to claim 4,

wherein the floating body is arranged in a cavity filled with a dielectric.

6. Gravimeter unit according to claim 1, further comprising:

a second floating body;

a second detector;

wherein a second position of the second floating body is detectable by the second detector; and

wherein the gravimeter unit is adapted to generate the first data on the basis of the measured first position and the measured second position.

7. Gravimeter unit according to claim 1, further comprising:

a control device;

wherein the control device is adapted to hold the first floating body in an initial position.

8. Gravimeter unit according to claim 7,

wherein, on the basis of the first floating body'"'"'s first position detected by the first detector, the control device controls a strength of the field generated by the source, so that the first floating body is held in the initial position;

and

wherein the gravimeter unit is adapted to generate the first data on the basis of a control parameter of the control device.

9. Gravimeter unit according to claim 1, further comprising:

a storage device;

wherein the storage device is adapted to store reference values.

10. Gravimeter unit according to claim 1,

wherein the gravimeter unit is provided on a semiconductor chip.

11. Sensor for detecting material on the basis of a gravitational field analysis, the sensor comprising:

a first gravimeter unit according to claim 1;

a second gravimeter unit according to claim 1;

a communication interface;

wherein the first gravimeter unit is adapted to determine first data corresponding to a first gravitational field strength at a first location;

wherein the second gravimeter unit is adapted to determine second data corresponding to a second gravitational field strength at a second location; and

wherein the communication interface is adapted to transfer the first data and the second data to an analysing unit.

12. Sensor according to claim 11,

wherein the determined first data are based on at least one of first floating body position data and first control parameters of a first control device;

and

wherein the determined second data are based on at least one of second floating body position data and on second control parameters of a second control device.

13. Sensor according to claim 11,

wherein the first and the second gravimeter units are disposed at fixed positions with respect to each other within the sensor.

14. Sensor according to claim 11,

wherein the first gravimeter unit is disposed rotatable about an axis or translatable along a shared axis;

wherein the first gravimeter unit during a rotation or translation is adapted to measure a first set of volume data comprising the first data.

15. Sensor according to claim 11,

wherein the sensor, besides the first gravimeter unit and the second gravimeter unit, comprises a plurality of third gravimeter units which, together with the first gravimeter unit and the second gravimeter unit, provide one of a one-dimensional, two-dimensional and three-dimensional array for measuring one of a set of line data, area data and volume data.

16. Sensor according to claim 11, further comprising:

an analysing unit;

wherein the analysing unit is adapted to receive the first data and the second data from the communication interface; and

wherein the analysing unit is adapted to calculate a gradient of a gravitational field on the basis of the first data and the second data.

17. Sensor according to claim 16,

wherein the analysing unit is adapted to calculate a local mass distribution in the surrounding area of the sensor.

18. Sensor according to claim 16,

wherein the analysing unit is adapted to calculate a filling level of a container on the basis of the first data and the second data.

19. Sensor according to claim 11,

wherein the sensor is provided on a semiconductor chip.

28. Sensor according to claim 11, wherein the sensor is a filling level measurement device.

29. Sensor according to claim 11, wherein the sensor is a proximity sensor.

30. Gravimeter according to claim 1, wherein the gravimeter is a filling level measurement device.

31. Gravimeter according to claim 1, wherein the gravimeter is a proximity sensor.

32. Gravimeter according to claim 1, wherein the gravimeter is a acceleration measurement device.

20. Method for filling level measurement of a filling good in a container on the basis of a gravitational field analysis, the method comprising the steps of:

determining of first data corresponding to a first gravitational field strength at a first location by a first gravimeter unit;

determining of second data corresponding to a second gravitational field strength at a second location by a second gravimeter unit;

calculating a filling level of the filling good on the basis of the determined first and second data.

21. Method according to claim 20, further comprising the steps of:

generating a field by a source;

detecting a first position of a first floating body of the first gravimeter unit by a first detector;

wherein the first floating body is contactlessly held in a floating state by a field generated by the source; and

wherein the first data are determined on the basis of the detected first position or the generated field.

22. Method according to claim 20,

wherein the field is selected from the group consisting of electric field, magnetic field, electromagnetic field and mechanical flow field.

23. Method according to claim 20,

wherein the first detector is adapted for at least one of capacitive, inductive, conductive and optical detection of the first position of the first floating body.

24. Method according to claim 20,

wherein the calculating of the filling level comprises a calculating of a gradient of a gravitational field in the neighbourhood of the filling good on the basis of the first data and the second data.

25. Method according to claim 20,

wherein within a sensor the first and the second gravimeter units are disposed at fixed positions with respect to each other.

26. Method according to claim 20, further comprising the step of:

rotating the first gravimeter unit about an axis or translating the first gravimeter unit along an axis;

wherein, during a rotation or translation, the first gravimeter unit is adapted for measuring a first set of volume data comprising the first data.

27. Method according to claim 20, further comprising the step of:

transmitting the first data and the second data via a communication interface to an analysing unit.

33. Program element for filling level measurement of a filling good in a container on the basis of a gravitational field analysis, wherein the program element, when executed on a processor, instructs the processor to execute the following operations:

determining of first data corresponding to a first gravitational field strength at a first location by a first gravimeter unit;

determining of second data corresponding to a second gravitational field strength at a second location by a second gravimeter unit;

calculating a filling level of the filling good on the basis of the determined first and second data.

34. A computer readable medium, onto which a computer program for filling level measurement of a filling good in a container on the basis of a gravitational field analysis is stored, wherein the computer program, when executed on a processor, instructs the processor to execute the following operations:

determining of first data corresponding to a first gravitational field strength at a first location by a first gravimeter unit;

determining of second data corresponding to a second gravitational field strength at a second location by a second gravimeter unit;

calculating a filling level of the filling good on the basis of the determined first and second data.