SENSOR DEVICE

• US 20090013783A1
• Filed: 09/04/2007
• Published: 01/15/2009
• Est. Priority Date: 10/20/2004
• Status: Active Grant

• Current Assignee: Imego Aktiebolag (Government of Sweden)
• Original Assignee: Imego Aktiebolag (Government of Sweden)
• Inventors: Rodjegard, Henrik, Andersson, Gert
• Granted Patent: US 7,814,791 B2
• Time in Patent Office: Days
• US Class Current: 73/504.30
• CPC Class Codes: G01C 21/166 Mechanical, construction or arrangement details of inertial navigation systems
• CPC Class Codes: G01P 15/18 in two or more dimensions

Abstract

The present invention is related to sensor arrangements and particularly to sensor arrangements for symmetric response in a x-, y- and z-coordinate system. The arrangement comprises four gyroscopes with one axis arranged into different directions of sensitivity.

Claims

1. A redundant sensor arrangement, for a symmetrical accuracy in an orthogonal x-, y- and z-coordinate system, wherein said arrangement comprises four one axis sensors said sensors being one of a gyroscope or accelerometer, each sensor having one sensitivity axis and each sensitivity axis is directed in one direction, whereby a symmetrical accuracy is obtained in all directions by choosing an angle of inclination (α

) between an xy-plane and each of said sensors and the angle of inclination (α

) for said sensors is chosen for an interval of 25°

-50°

, preferably at approximately 35°

, i.e. arctan (1/√

{square root over (2)})=35.5°

.

2. The arrangement according to claim 1, wherein the sensor arrangement is manufactured and encapsulated and/or mounted with the sensitivity direction in the direction of the corresponding angle of inclination (a).

3. The arrangement according to claim 1, wherein the sensor arrangement is manufactured with the right sensitivity direction on the same chip, where the chip comprises two or four sensor elements.

4. The arrangement according to claim 1, wherein the sensor arrangement is mounted onto sockets being inclined at said corresponding angle of inclination (α

).

5. The arrangement according to claim 1, wherein the sensor arrangement is mounted on a structure with leaning carrier surfaces.

6. The arrangement according to claim 1, wherein the sensor arrangement is mounted onto a flexible substrate which is fastened onto wedges.

7. The arrangement according to claim 1, wherein the sensor arrangement is mounted onto a mechanical fixture.

8. The arrangement according to claim 1, wherein said angle (α

) is located in the interval 40°

-65°

, preferably at approximately 55°

. i.e. 90°

-arctan(1/√

{square root over (2)}) if the axis of sensitivity for the sensor is vertical.

9. The arrangement according to claim 1, wherein four carrier structures are leaningly mounted and arranged essentially side by side forming the sides of an essentially pyramid-shaped structure, where each carrier structure comprises one gyroscope with one axis.

10. The arrangement according to claim 9, wherein four gyroscopes are arranged as accelerometers with three axes and with four masses arranged on a carrier structure building the top or the bottom plane of said leaning structures.

11. The arrangement according to claim 1, wherein four carrier structures are leaningly mounted and arranged essentially side by side, forming sides of an essentially pyramid-shaped structure, where each carrier structure comprises an accelerometer with one axis.

12. The arrangement according to claim 11, wherein the sensitivity axis for the gyros and possible accelerometers with one axis is parallel to the planes of the carrier structures and directed upwards or downwards in relation to the plane for obtaining optimum configuration with an approximate angle of inclination (α

) with the base.

13. The arrangement according to claim 1, wherein the sensors are mounted in right angles by means of plane substrates located on wedges.

14. The arrangement according to claim 1, wherein the carrier structures is a substrate provided with a recess with leaning walls, where one end of a gyroscope is arranged to be leaning against one of the leaning walls, where the angel between the sensitivity axis for the gyroscope and the gyroscope corresponds to the angle of inclination (α

).

15-18. -18. (canceled)