Methods for compensating parameters of operating accelerometer for temperature variations

• US 20090090183A1
• Filed: 10/06/2008
• Published: 04/09/2009
• Est. Priority Date: 10/05/2007
• Status: Abandoned Application

• Current Assignee: IMU Solution, Inc.
• Original Assignee: IMU
• Inventors: Lou, Ruey-Der
• Application Number:
  US12/287,243
• Publication Number:
  US 20090090183A1
• Time in Patent Office: Days
• US Class Current: 73/497
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01C 9/00 Measuring inclination, e.g. by clinometers, by levels
• CPC Class Codes: G01P 1/006 used for thermal compensation
• CPC Class Codes: G01P 21/00 Testing or calibrating of apparatus or devices covered by the preceding groups

Abstract

A method is disclosed in this invention for compensating a temperature dependent variation of an offset V_offset and sensitivity V_sensitivity parameters of an accelerometer. The method includes steps of a) Measuring a Sensitivity V_sensitivity(T0) and an Offset V_offset(T0) at a room temperature T0 to input to a microprocessor to calculate two tilt angles θ1 and θ2 in placing the accelerometer in a furnace for adjusting a controllable temperature therein; b) Keeping the accelerometer at the fixed tilt angle θ1 and adjusting the temperature of the furnace for measuring an output voltage at θ1 Vo(T, θ1) and keeping the accelerometer at another fixed tilt angle θ2 and adjusting the temperature of the furnace for measuring an output voltage at θ2 Vo(T, θ2); and c) solving equations to obtain the offset V_offset and sensitivity V_sensitivity parameters at different temperatures and storing these parameters in the microprocessor.

Claims

1. A method for compensating a temperature dependent variation of an offset V_offset and sensitivity V_sensitivity parameters of an accelerometer comprising:

measuring a Sensitivity V_sensitivity(T0) and an Offset V_offset(T0) at a room temperature T0 to input to a microprocessor to calculate two tilt angles θ

1 and θ

2 in placing the accelerometer in a furnace for adjusting a controllable temperature therein;

keeping the accelerometer at the fixed tilt angle θ

1 and adjusting the temperature of said furnace for measuring an output voltage at θ

1 Vo(T, θ

1) and keeping the accelerometer at another fixed tilt angle θ

2 and adjusting the temperature of said furnace for measuring an output voltage at θ

2 Vo(T, θ

2);

solving equations to obtain the offset V_offset and sensitivity V_sensitivity parameters at different temperatures and storing these parameters in the microprocessor.

2. The method of claim 1 wherein:

the room temperature applied for measuring the Sensitivity V_sensitivity(T0) and an Offset V_offset(T0) is at a temperature T0=25°

C.

3. The method of claim 1 wherein:

the step of adjusting the temperature of the furnace is a step of adjusting the temperature of the furnace for measuring the output voltage at θ

1 Vo(T, θ

1) by increasing and decreasing the temperature every 0.5°

C. between a range of 0°

C. ˜

50°

C.

4. A method for calibrating a temperature compensation for an accelerometer with an offset V_offset and sensitivity V_sensitivity implemented in a level gauge having a known value of an offset angle θ

_Δ

a comprising;

placing the level gauge implemented with the accelerometer in a furnace to control a temperature variation and measuring an output voltage of the accelerometer at several tilt angles for calculating different values of V_offset and sensitivity V_sensitivity at different temperatures.