METHOD FOR OPERATING A MICROMECHANICAL Z-ACCELEROMETER

• US 20170248629A1
• Filed: 02/21/2017
• Published: 08/31/2017
• Est. Priority Date: 02/29/2016
• Status: Abandoned Application

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hammer, Kay, Franke, Axel, Guenther, Sebastian
• Application Number:
  US15/438,040
• Publication Number:
  US 20170248629A1
• Time in Patent Office: Days
• CPC Class Codes: G01P 15/125 by capacitive pick-up
• CPC Class Codes: G01P 2015/0831 the mass being of the paddle type having the pivot axis between the longitudinal ends of the mass, e.g. see-saw configuration
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A method for operating a micromechanical z-accelerometer. The method includes applying a test signal to an electrode in order to induce a defined displacement of a rocker of the z-accelerometer during operation of the z-accelerometer; detecting the displacement of the rocker and converting the displacement into an acceleration value; and evaluating the acquired acceleration value by determining a difference between the acquired acceleration value and an initial acceleration value acquired in a manufacturing process, a difference between the acquired acceleration value and the initial acceleration value being compared to a defined threshold value and assessed.

Claims

1. A method for operating a micromechanical z-accelerometer, comprising:

applying a test signal to an electrode to induce a defined displacement of a rocker of the z-accelerometer during operation of the z-accelerometer;

detecting the displacement of the rocker and converting the displacement into an acceleration value; and

evaluating the acquired acceleration value by determining a difference between the acquired acceleration value and an initial acceleration value acquired in a manufacturing process, a difference between the acquired acceleration value and the initial acceleration value being compared to a defined threshold value and assessed.

2. The method as recited in claim 1, wherein the acceleration value is acquired repeatedly at defined time intervals.

3. The method as recited in claim 1, wherein a correlation is determined between an acceleration value acquired without applied test signal and an acceleration value acquired with applied test signal, the correlation having the following mathematical function:

Offsetdrift=C0+C1*(B1−

B0)

wherein C0, C1 are design-specific coefficients, B1 is the acquired acceleration value, and B0 is the initial acceleration value; and

wherein the correlation is used for a correction of the acceleration value determined during operation of the z-accelerometer.

4. The method as recited in claim 3, wherein the test signal and an algorithm for recognizing and correcting the offset drift of the z-accelerometer are controlled with the aid of a computer program product.

5. A micromechanical z-accelerometer, comprising:

a determination device to determine acceleration values of the z-accelerometer; and

a recognition device functionally connected to the determination device and designed to recognize and assess a difference between an initial acceleration value and an acceleration value acquired during operation of the z-accelerometer.

6. The micromechanical z-accelerometer as recited in claim 5, wherein the initial acceleration value and design-specific coefficients for correcting an offset drift of the acceleration value are stored in a memory of the z-accelerometer.

7. The micromechanical z-accelerometer as recited in claim 5, wherein the acceleration value is correctable with the aid of a correction device.

8. A non-transitory computer readeable storage medium on which is stored a computer program for operating a micromechanical z-accelerometer, the computer program, when executed by a control device, causing the control device to perform:

applying a test signal to an electrode to induce a defined displacement of a rocker of the z-accelerometer during operation of the z-accelerometer;

detecting the displacement of the rocker and converting the displacement into an acceleration value; and

evaluating the acquired acceleration value by determining a difference between the acquired acceleration value and an initial acceleration value acquired in a manufacturing process, a difference between the acquired acceleration value and the initial acceleration value being compared to a defined threshold value and assessed.