METHOD FOR CALIBRATING YAW RATE SENSORS

• US 20140116108A1
• Filed: 10/21/2013
• Published: 05/01/2014
• Est. Priority Date: 10/25/2012
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: HATTASS, Mirko, FRANKE, Axel
• Granted Patent: US 9,791,275 B2
• Time in Patent Office: Days
• US Class Current: 73/1.37
• CPC Class Codes: G01C 19/5755 the devices having a single sensing mass
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices

Abstract

A method for calibrating a selected yaw rate sensor includes: determining a scaling function between a yaw rate sensitivity and a test signal sensitivity of a yaw rate sensor selected for carrying out a test and denoted as first sampling yaw rate sensor is determined in a first method step, the scaling function being determined from a measured first sample yaw rate sensitivity and from a measured first sample test signal sensitivity of the sampling yaw rate sensor; calculating a production yaw rate sensitivity for a yaw rate sensor denoted as production yaw rate sensor from a measured production test signal sensitivity of the production yaw rate sensor and the scaling function; and subsequently calibrating the production yaw rate sensor with the aid of the production yaw rate sensitivity.

Claims

1. A method for calibrating a selected yaw rate sensor which includes a substrate having a main plane of extent, a seismic mass movable in relation to the substrate, a drive device for deflecting the seismic mass in a drive direction, a detection device for detecting a force action of the seismic mass in a detection direction perpendicular to the drive direction, and a test device for deflecting the seismic mass parallel to the detection direction, the method comprising:

measuring a drive frequency on the drive device;

measuring a detection frequency on the detection device;

applying a yaw rate about an axis of rotation to at least one yaw rate sensor for measuring a yaw rate sensitivity, and subsequently measuring an output voltage on the detection device as a function of the yaw rate;

applying a test signal to the test device for determining a test signal sensitivity, and subsequently measuring a detection voltage on the detection device as a function of the test signal;

determining a scaling function between a yaw rate sensitivity and a test signal sensitivity of a yaw rate sensor selected for carrying out a test and denoted as a first sampling yaw rate sensor, wherein the scaling function is determined from a measured first sample yaw rate sensitivity and from a measured first sample test signal sensitivity of the sampling yaw rate sensor;

calculating a production yaw rate sensitivity for a yaw rate sensor denoted as a production yaw rate sensor from a measured production test signal sensitivity of the production yaw rate sensor and the scaling function; and

subsequently calibrating the production yaw rate sensor with the aid of the production yaw rate sensitivity.

2. The method as recited in claim 1, wherein:

the scaling function is additionally determined from a measured second sample test signal sensitivity and a measured second sample yaw rate sensitivity of a second sampling yaw rate sensor, the scaling function being determined as a function of at least one of (i) a first and second sample drive frequency and (ii) a first and second sample detection frequency;

the production yaw rate sensitivity is calculated for the production yaw rate sensor from the measured production test signal sensitivity, the value of the scaling function, and at least one of a measured production drive frequency and a measured production detection frequency;

the scaling function is calculated as a function of at least one of the measured production drive frequency and the measured production detection frequency; and

the scaling function is interpreted linearly as a function of at least one of the production drive frequency and the production detection frequency.

3. The method as recited in claim 1, wherein a quadrature signal is used as a test signal for determining the test signal sensitivity.

4. The method as recited in claim 2, wherein:

for measuring the first and second sample yaw rate sensitivity, the axis of rotation extends perpendicularly to the main plane of extent; and

for measuring an additional first sample yaw rate sensitivity of the first sampling yaw rate sensor, an additional axis of rotation extends parallel to the main plane of extent and perpendicularly to the axis of rotation.

5. The method as recited in one of the preceding claim 2, wherein in the case of a yaw rate sensor having sensitivity about the axis of rotation and the additional axis of rotation:

an additional scaling function is additionally determined for the first sampling yaw rate sensor between the test signal sensitivity, the yaw rate sensitivity, an additional test signal sensitivity, and an additional yaw rate sensitivity from the measured first sample signal sensitivity and the measured first sample yaw rate sensitivity and from a measured additional first sample test signal sensitivity and a measured additional first sample yaw rate sensitivity;

an additional production yaw rate sensitivity is additionally calculated for the production yaw rate sensor from the calculated production yaw rate sensitivity, the additional scaling function, the measured production test signal sensitivity and a measured additional production test signal sensitivity; and

the production yaw rate sensor is subsequently calibrated with the aid of the additional production yaw rate sensitivity.