FORCE MEASURING DEVICE AND METHOD FOR SIGNAL EVALUATION

• US 20100013465A1
• Filed: 08/14/2009
• Published: 01/21/2010
• Est. Priority Date: 02/20/2007
• Status: Abandoned Application

• Current Assignee: Bag Bizerba Automotive GmbH (Bizerba SE & Co. KG)
• Original Assignee: Bag Bizerba Automotive GmbH (Bizerba SE & Co. KG)
• Inventors: Sautter, Sven, Hampe, Andreas
• Application Number:
  US12/541,192
• Publication Number:
  US 20100013465A1
• Time in Patent Office: Days
• US Class Current: 324/207.110
• CPC Class Codes: B41F 21/00 Devices for conveying sheets through printing apparatus or machines through platen presses B41F1/28
• CPC Class Codes: B41F 33/0036 Devices for scanning or checking the printed matter for quality control
• CPC Class Codes: G01D 5/145 influenced by the relative movement between the Hall device and magnetic fields see G01R33/06
• CPC Class Codes: G01G 19/4142 for controlling activation of safety devices, e.g. airbag systems electrical circuits for triggering safety arrangements in case of vehicle accidents B60R21/015
• CPC Class Codes: G01L 1/122 by using permanent magnets

Abstract

A force measuring device is provided, which comprises a transducer device that has a plurality of magnets and generates a magnetic field, and a sensor device that is sensitive to a magnetic field and is arranged in a space in front of the transducer device, the transducer device and the sensor device being movable relative to each other under the action of a force, wherein the magnets of the transducer device are positioned in a quadrupole arrangement relative to the sensor device, and the sensor device comprises at least one first sensor element and one second sensor element, the first sensor element being associated with a first magnetic pole or a first pair of magnetic poles, and the second sensor element being associated with a second magnetic pole or a second pair of magnetic poles.

Claims

1. A force measuring device, comprising:

a transducer device that has a plurality of magnets and generates a magnetic field; and

a sensor device that is sensitive to a magnetic field and is arranged in a space in front of the transducer device;

wherein the transducer device and the sensor device are movable relative to each other under the action of a force;

wherein the magnets of the transducer device are positioned in a quadrupole arrangement relative to the sensor device; and

wherein the sensor device comprises at least one first sensor element and one second sensor element;

wherein the first sensor element is associated with a first magnetic pole or a first pair of magnetic poles; and

wherein the second sensor element is associated with a second magnetic pole or a second pair of magnetic poles.

2. The force measuring device in accordance with claim 1, wherein one sensor element or two sensor elements is or are associated with each magnetic pole of the quadrupole arrangement.

3. The force measuring device in accordance with claim 1, wherein one sensor element is associated with each pair of magnetic poles of the quadrupole arrangement.

4. The force measuring device in accordance with claim 1, wherein two respective magnetic poles with the same sign in the quadrupole arrangement face the sensor device.

5. The force measuring device in accordance with claim 1, wherein next adjacent magnetic poles in the quadrupole arrangement have a different sign.

6. The force measuring device in accordance with claim 1, wherein diagonally opposed magnetic poles in the quadrupole arrangement have the same sign.

7. The force measuring device in accordance with claim 1, wherein the transducer device is formed by permanent magnets.

8. The force measuring device in accordance with claim 1, wherein the transducer device comprises two magnets or four magnets.

9. The force measuring device in accordance with claim 1, wherein the magnets of the transducer device are of essentially identical configuration.

10. The force measuring device in accordance with claim 1, wherein the transducer device comprises bar magnets whose magnetic poles lie along the longest axis of extent.

11. The force measuring device in accordance with claim 1, wherein the transducer device comprises magnets whose magnetic poles lie along an axis of extent, which is transverse to the longest axis of extent.

12. The force measuring device in accordance with claim 1, wherein the transducer device has a first center plane in relation to which the magnets are geometrically symmetrical.

13. The force measuring device in accordance with claim 12, wherein the signs of the magnetic poles are antisymmetrical in relation to the first center plane.

14. The force measuring device in accordance with claim 12, wherein the transducer device has a second center plane which is transverse to the first center plane in relation to which the magnets are geometrically symmetrical.

15. The force measuring device in accordance with claim 14, wherein the signs of the magnetic poles are antisymmetrical in relation to the second center plane.

16. The force measuring device in accordance with claim 12, wherein one or more magnets is or are arranged at an acute angle in relation to at least one of the first center plane and the second center plane.

17. The force measuring device in accordance with claim 16, wherein a point of intersection of axes of extent of magnets that are arranged at an acute angle lies in the space in front of the transducer device.

18. The force measuring device in accordance with claim 1, wherein the magnets are arranged and configured in such a way that there is a central region that is at least approximately free of a magnetic field.

19. The force measuring device in accordance with claim 18, wherein the central region that is free of a magnetic field lies at the point of intersection of a first center plane and a second center plane of the transducer device.

20. The force measuring device in accordance with claim 1, wherein a central region of the quadrupole arrangement has a sensor element of its own associated with it.

21. The force measuring device in accordance with claim 1, wherein at least one sensor element is associated with each magnetic pole.

22. The force measuring device in accordance with claim 21, wherein the sensor device comprises a third sensor element and a fourth sensor element.

23. The force measuring device in accordance with claim 1, wherein the sensor elements of the sensor device are arranged symmetrically in relation to a first center plane.

24. The force measuring device in accordance with claim 23, wherein the sensor elements of the sensor device are arranged symmetrically in relation to a second center plane which is transverse to the first center plane.

25. The force measuring device in accordance with claim 23, wherein the first center plane of the sensor device coincides with a first center plane of the transducer device when there is no relative deflection between transducer device and sensor device.

26. The force measuring device in accordance with claim 23, wherein the first center plane of the sensor device lies at an angle to a first center plane of the transducer device.

27. The force measuring device in accordance with claim 23, wherein the second center plane of the sensor device coincides with a second center plane of the transducer device when there is no relative deflection between transducer device and sensor device.

28. The force measuring device in accordance with claim 23, wherein the second center plane of the sensor device lies at an angle to a second center plane of the transducer device.

29. The force measuring device in accordance with claim 1, wherein sensor elements of the sensor device are arranged at the corners of a quadrilateral.

30. The force measuring device in accordance with claim 29, wherein the quadrilateral of the sensor device is congruent with a quadrilateral at the corners of which the magnetic poles lie, or the quadrilateral of the sensor device is at an angle to the quadrilateral of the magnetic poles.

31. The force measuring device in accordance with claim 29, wherein a further sensor element is arranged at a diagonal point of intersection of the quadrilateral.

32. The force measuring device in accordance with claim 1, wherein a sensor element associated with one or more magnetic poles is positioned in a projection space of the magnetic pole or poles in front of the magnetic pole or poles in the direction of the sensor device.

33. The force measuring device in accordance with claim 1, wherein the sensor elements are Hall elements.

34. The force measuring device in accordance with claim 1, wherein an evaluation device is provided for linking the signals of different sensor elements.

35. The force measuring device in accordance with claim 34, wherein the evaluation device comprises a differential unit for forming a difference between signals of different sensor elements.

36. The force measuring device in accordance with claim 34, wherein the evaluation device comprises an adding unit for adding up signals of different sensor elements.

37. The force measuring device in accordance with claim 1, wherein the transducer device or the sensor device is connected to an elastic force transducer.

38. The force measuring device in accordance with claim 37, wherein the force transducer is configured as a hollow bar.

39. The force measuring device in accordance with claim 38, wherein the transducer device and the sensor device are arranged in an interior of the hollow bar.

40. A method for evaluating signals in a force measuring device, said force measuring device comprising:

a transducer device that has a plurality of magnets and generates a magnetic field; and

a sensor device that is sensitive to a magnetic field and is arranged in a space in front of the transducer device;

wherein the transducer device and the sensor device are movable relative to each other under the action of a force;

wherein the magnets of the transducer device are positioned in a quadrupole arrangement relative to the sensor device; and

wherein the sensor device comprises at least one first sensor element and one second sensor element;

wherein the first sensor element is associated with a first magnetic pole or a first pair of magnetic poles; and

wherein the second sensor element is associated with a second magnetic pole or a second pair of magnetic poles;

said method comprising at least one of;

(i) forming a difference between signals of different sensor elements; and

(ii) measuring a magnetic field in a central region of the quadrupole arrangement by a sensor element associated with the central region; and

(iii) evaluating the signals of diagonally opposed sensor elements.

41. The method in accordance with claim 40, wherein a difference is formed with the signals of a first pair of sensor elements and the signals of a second pair of sensor elements, a direction of connection between the sensor elements of the first pair lying transversely to a direction of connection between the sensor elements of the second pair.

42. The method in accordance with claim 40, wherein the signals of four sensor elements positioned at the corners of a quadrilateral are evaluated.

43. The method in accordance with claim 40, wherein a main pole approximation is carried out.

44. The method in accordance with claim 40, wherein an addition is performed when evaluating the signals of diagonally opposed sensor elements.

45. The method in accordance with claim 40, wherein an interference field in a central region of the quadrupole arrangement is measured and taken into account in the evaluation.