YAW-RATE SENSOR

• US 20120060604A1
• Filed: 10/02/2008
• Published: 03/15/2012
• Est. Priority Date: 11/15/2007
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Neul, Reinhard, Classen, Johannes, Ohms, Torsten, Kuhlmann, Burkhard, Franke, Axel, Kohn, Oliver, Meisel, Daniel Christoph, Hauer, Joerg, Gomez, Udo-Martin, Kehr, Kersten
• Granted Patent: US 9,081,027 B2
• Time in Patent Office: Days
• US Class Current: 73/504.12
• CPC Class Codes: F16F 1/025 characterised by having a particular shape F16F1/04, F16F1/14, F16F1/18, F16F1/32, F16F1/34 take precedence
• CPC Class Codes: G01C 19/574 the devices having two sensing masses in anti-phase motion
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: G01P 3/44 for measuring angular speed G01P3/56 takes precedence

Abstract

A yaw-rate sensor having a substrate and a plurality of movable substructures that are mounted over a surface of the substrate, the movable substructures being coupled to a shared, in particular, central spring element, means being provided for exciting the movable substructures into a coupled oscillation in a plane that extends parallel to the surface of the substrate, the movable substructures having Coriolis elements, means being provided for detecting deflections of the Coriolis elements induced by a Coriolis force, a first Coriolis element being provided for detecting a yaw rate about a first axis, a second Coriolis element being provided for detecting a yaw rate about a second axis, the second axis being oriented perpendicularly to the first axis.

Claims

1-19. -19. (canceled)

20. A yaw-rate sensor comprising:

a substrate and a plurality of movable substructures that are mounted over a surface of the substrate, the movable substructures being coupled to a shared spring element and the movable substructures having Coriolis elements;

means for exciting the movable substructures into a coupled oscillation in a plane that extends parallel to the surface of the substrate;

means for detecting deflections of the Coriolis elements caused by a Coriolis force;

a first Coriolis element for detecting a yaw rate about a first axis; and

a second Coriolis element for detecting a yaw rate about a second axis;

wherein the second axis is not oriented parallel to the first axis.

21. The yaw-rate sensor as recited in claim 20, each Coriolis element being connected via additional spring elements to a drive frame of one of the substructures;

the Coriolis elements being connected to the shared spring element.

22. The yaw-rate sensor as recited in claim 20, each Coriolis element being connected via additional spring elements to a drive frame of one of the substructures;

and the drive frame of each substructure being connected to the shared spring element.

23. The yaw-rate sensor as recited in claim 20, a common center of mass of at least two movable substructures remaining fixed during one oscillatory period.

24. The yaw-rate sensor as recited in claim 20, at least one Coriolis element being connected via flexural spring elements to a substructure;

the flexural spring elements exhibiting a high level of stiffness in the direction of the oscillation of the substructure;

the flexural spring elements exhibiting a low level of stiffness in a second direction which is oriented perpendicularly to the direction of oscillation of the substructure and parallel to the surface of the substrate; and

means being provided for detecting a deflection of the Coriolis element in the second direction, caused by a Coriolis force.

25. The yaw-rate sensor as recited in claim 20, at least one Coriolis element being designed as a rocker;

the Coriolis element being connected via torsional spring elements to a substructure;

the torsional spring elements forming a rotary axis of motion of the rocker that extends parallel to the surface of the substrate;

the two sides of the rocker having different masses, in response to a Coriolis force acting perpendicularly to the surface of the substrate, the Coriolis element being rotatable about the rotary axis of motion; and

means being provided for detecting a rotation of the Coriolis element.

26. The yaw-rate sensor as recited in claim 20, at least one Coriolis element being connected via flexural spring elements to a substructure;

the flexural spring elements exhibiting a high level of stiffness in directions that extend parallel to the surface of the substrate;

the flexural spring elements exhibiting a low level of stiffness in a second direction that extends perpendicularly to the surface of the substrate; and

means being provided for detecting a deflection of the Coriolis element in the second direction, caused by a Coriolis force.

27. The yaw-rate sensor as recited in claim 20, at least one movable substructure having more than one Coriolis element.

28. The yaw-rate sensor as recited in claim 20, further comprising means for exciting two movable substructures into an oscillation mode that essentially induces an antiphase deflection of the two movable substructures along a shared axis.

29. The yaw-rate sensor as recited in claim 28, the two movable substructures, which are excitable into a common oscillation mode accompanied by antiphase deflection, having one Coriolis element each;

the two Coriolis elements being deflectable in opposite directions in response to a Coriolis force.

30. The yaw-rate sensor as recited in claim 20, four movable substructures being provided;

means being provided for exciting the four movable substructures into a coupled oscillation mode;

which essentially induces an antiphase deflection of a first and of a second movable substructure along a first axis; and

which essentially induces an antiphase deflection of a third and of a fourth movable substructure along a second axis.

31. The yaw-rate sensor as recited in claim 30, further comprising means for exciting an oscillation mode whereby the deflection of the first and second movable substructure proceeds in phase with the deflection of the third and fourth movable substructure.

32. The yaw-rate sensor as recited in claim 30, further comprising means for exciting an oscillation mode whereby the deflection of the first and second movable substructure proceeds in phase opposition to the deflection of the third and fourth movable substructure.

33. The yaw-rate sensor as recited in claim 30, the Coriolis elements being provided for determining yaw rates about three mutually perpendicularly extending axes.

34. The yaw-rate sensor as recited in claim 30, the first and the second movable substructure having a substantially identical first mass;

the third and the fourth movable substructure having a substantially identical second mass;

the central spring element having a first spring stiffness in the direction of the first axis;

the central spring element having a second spring stiffness in the direction of the second axis; and

the first mass, the second mass, the first spring stiffness and the second spring stiffness being selected in such a way that the four movable substructures are excitable into an oscillation mode having substantially the same deflection amplitude for all four movable substructures.

35. The yaw-rate sensor as recited in claim 30, the third and the fourth movable substructure being mounted on the surface of the substrate in such a way that a portion of the surface of the third and fourth movable substructure covers a region of the surface of the substrate that resides between the first and the second movable substructure.

36. The yaw-rate sensor as recited in claim 20, the shared spring element being composed of a plurality of tines and connecting elements;

each tine including a first kink at a 90°

counterclockwise position, a first straight section of a first length, a second kink at a 90°

clockwise position, a second straight section of a second length, a third kink at a 90°

clockwise position, and a third section of a first length;

each connecting element having a fourth kink at a 90°

counterclockwise position and a fourth section of a third length;

each tine being followed by either a connecting element or another tine;

a tine following each connecting element; and

the spring element forming a closed ring.

37. The yaw-rate sensor as recited in claim 20, the shared spring element being designed as a ring, the movable substructures being coupled to the central spring element via connecting pieces that are joined to the ring.

38. The yaw-rate sensor as recited in claim 20, wherein the movable substructures are coupled to a shared, central spring element and wherein the second axis is oriented perpendicular to the first axis.

39. A micromechanical ladder spring for suspending Coriolis elements, comprising:

two substantially parallel bars;

the two bars being joined over the length thereof by a plurality of connecting rungs; and

wherein interspacing between the plurality of connecting rungs is at least as great as the distance between the bars.