Measurement system comprising an acceleration sensor and a position sensor

• US 6,736,009 B1
• Filed: 07/24/2002
• Issued: 05/18/2004
• Est. Priority Date: 09/30/1999
• Status: Expired due to Fees

• Current Assignee: Dr. Johannes Heidenhain GmbH
• Original Assignee: Dr Johannes Heidenhain GmbH
• Inventors: Schwabe, Michael
• Primary Examiner(s): KWOK, HELEN C
• Application Number:
  US10/089,624
• Time in Patent Office: 664 Days
• Field of Search: 735/143.1, 735/142.6, 735/143.9, 735/190.1, 735/200.1, 324/164, 324/173, 324/174, 324/207.22, 324/207.25, 324/207.12, 324/162, 324/225, 324/232
• US Class Current: 73/514.31
• CPC Class Codes: G01P 15/003 Kinematic accelerometers, i.e. measuring acceleration in relation to an external reference frame, e.g. Ferratis accelerometers G01P15/001, G01P15/16, G01P15/165 take precedence
• CPC Class Codes: G01P 15/005 measuring translational acceleration
• CPC Class Codes: G01P 15/0888 for indicating angular acceleration
• CPC Class Codes: G01P 3/486 delivered by photo-electric detectors

Abstract

A measurement system for determining acceleration and a position of an object. The measurement system includes a first sensor system for determining an acceleration of an object, the first sensor having a body with an electrically conducting measuring structure, a device for generating a first magnetic field, which acts on the measuring structure and a detector for detecting a second magnetic field or field changes, which are created by eddy currents generated by the measuring structure, the detector generating an output signal. A second sensor system for determining a position of the object, the second sensor system includes a scale graduation that lies opposite the detector and is scanned by the detector in a scanning area in which the measuring structure and the scale graduation are arranged placed on top of each other, or integrated into each other, and wherein the detector generates an acceleration signal and a position signal from a common scanning area. The measuring structure and the scale graduation are formed on a common body.

Claims

1. A measurement system for determining acceleration and a position of an object, comprising:

a first sensor system for determining an acceleration of an object, said first sensor system comprising;

a body with an electrically conducting measuring structure;

a device for generating a first magnetic field, which acts on said measuring structure; and

a detector for detecting a second magnetic field or field changes, which are created by eddy currents generated by said measuring structure, said detector generating an output signal;

a second sensor system for determining a position of said object, said second sensor system comprises a scale graduation that lies opposite said detector and is scanned by said detector in a scanning area in which said measuring structure and said scale graduation are arranged placed on top of each other, or integrated into each other, and wherein said detector generates an acceleration signal and a position signal from a common scanning area; and

said measuring structure and said scale graduation are formed on a common body.

2. The measurement system in accordance with claim 1, wherein said scale graduation comprises electrically conducting areas.

3. The measurement system in accordance with claim 1, wherein said measuring structure is structured in such a way that said second magnetic field varies as a function of a position in a movement direction of said body.

4. The measurement system in accordance with claim 2, wherein said measuring structure is structured in such a way that said second magnetic field varies as a function of a position in a movement direction of said body.

5. The measurement system in accordance with claim 1, wherein said acceleration signal is superimposed on said position signal.

6. The measurement system in accordance with claim 4, wherein said acceleration signal is superimposed on said position signal.

7. The measurement system in accordance with claim 1, further comprising:

a filter that receives said acceleration signal and selects high-frequency signals; and

high-frequency components that generate said position signal.

8. The measurement system in accordance with claim 1, further comprising:

a second detector that generates a second output signal;

a switching device that selects either said output signal or said second output signal as said acceleration signal.

9. The measurement system in accordance with claim 8, where said scale graduation comprises a partially electrically conducting area.

10. The measurement system in accordance with claim 2, wherein said scale graduation comprises a layer or a layer package which is applied on said electrically conducting areas.

11. The measurement system in accordance with claim 10, wherein said measuring structure comprises a layer or a layer package of electrically conducting material on an electrically non-conducting support.

12. A measurement system for determining acceleration and a position of an object, comprising:

a first sensor system for determining an acceleration of an object, said first sensor system comprising;

a body with an electrically conducting measuring structure;

a device for generating a first magnetic field, which acts on said measuring structure; and

a first detector for detecting a second magnetic field or field changes, which are created by eddy currents generated by said measuring structure, said first detector generating an output signal;

a second sensor system for determining a position of said object, said second sensor system comprises a scale graduation that lies opposite said first detector and is scanned by a position detector in a scanning area in which said measuring structure and said scale graduation are arranged placed on top of each other, or integrated into each other, and wherein said first detector generates an acceleration signal and said position detector generates a position signal from a common scanning area; and

said measuring structure and said scale graduation are formed on a common body.

13. The measurement system in accordance with claim 12, wherein said scale graduation comprises electrically conducting areas.

14. The measurement system in accordance with claim 12, wherein said measuring structure is structured in such a way that said second magnetic field varies as a function of a position in a movement direction of said body.

15. The measurement system in accordance with claim 13, wherein said measuring structure is structured in such a way that said second magnetic field varies as a function of a position in a movement direction of said body.

16. The measurement system in accordance with claim 12, further comprising:

a second detector that generates a second output signal;

a switching device that selects either said output signal or said second output signal as said acceleration signal.

17. The measurement system in accordance with claim 16, where said scale graduation comprises a partially electrically conducting area.

18. The measurement system in accordance with claim 17, wherein said scale graduation comprises a layer or a layer package which is applied on said partially electrically conducting area.

19. The measurement system in accordance with claim 12, wherein said scale graduation is embodied to reflect light and comprises elevations and depressions which are alternatingly arranged in a movement direction of said body.

20. The measurement system in accordance with claim 19, wherein said elevations comprise electrically conducting areas, whose dimensions are selected to be so small that no eddy currents are created.

21. The measurement system in accordance with claim 12, wherein said scale graduation is structured to be photoelectrically scannable and wherein said detector comprises an optical scanning head for scanning said scale graduation.

22. The measurement system in accordance with claim 13, wherein said scale graduation comprises a layer or a layer package which is applied on said electrically conducting areas.

23. The measurement system in accordance with claim 22, wherein said measuring structure comprises a layer or a layer package of electrically conducting material on an electrically non-conducting support.