OFFSET COMPENSATION CIRCUIT AND YAW RATE SENSOR EQUIPPED THEREWITH

• US 20090121769A1
• Filed: 11/12/2008
• Published: 05/14/2009
• Est. Priority Date: 11/14/2007
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: BAUS, Michael
• Granted Patent: US 8,024,147 B2
• Time in Patent Office: Days
• US Class Current: 327/307
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01D 3/032 affecting incoming signal, e.g. by averaging; gating undesired signals
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

An offset compensation circuit for a yaw rate sensor, having a subtracter, which is provided for subtracting a correction value from an input signal, the correction value being obtainable by dividing each of n measurements of the input signal by the constant n and subsequently integrating a number of n quotients into an integrator. Furthermore, a yaw rate sensor having such an offset compensation circuit.

Claims

1. An offset compensation circuit for a yaw rate sensor, comprising:

a subtracter for subtracting a correction value from an input signal, the correction value being a function of an average of n measurements of the input signal.

2. The offset compensation circuit according to claim 1, further comprising an adder and a delay element for averaging, which is provided for forming a sum of an input signal with an output signal of the adder, delayed by one cycle.

3. The offset compensation circuit according to claim 2, further comprising a device for setting the output signal of the adder to zero before adding a first input value.

4. The offset compensation circuit according to claim 1, wherein the number n is between 2 and 2048.

5. The offset compensation circuit according to claim 1, wherein the number n is 256.

6. The offset compensation circuit according to claim 1, wherein the number n corresponds to a power of two.

7. The offset compensation circuit according to claim 2, further comprising an analog-digital converter for supplying the input signal.

8. The offset compensation circuit according to claim 1, further comprising a low-pass filter for filtering at least one of the input signal and an output signal of the subtracter.

9. The offset compensation circuit according to claim 1, wherein an offset compensation runs once after a power supply is turned on or after a reset.

10. The offset compensation circuit according to claim 1, further comprising a trigger terminal for causing an offset compensation to run.

11. A yaw rate sensor comprising:

an offset compensation circuit including a subtracter for subtracting a correction value from an input signal, the correction value being a function of an average of n measurements of the input signal.