Apparatus and method for correcting inertial sensor and recording medium recording the method

• US 7,451,633 B2
• Filed: 02/15/2006
• Issued: 11/18/2008
• Est. Priority Date: 02/15/2005
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Cho, Joon-kee, Bang, Won-chul, Cho, Sung-jung, Choi, Eun-seok, Kim, Dong-yoon, Oh, Jong-koo
• Primary Examiner(s): Raevis; Robert R
• Application Number:
  US11/353,988
• Publication Number:
  US 20060179915A1
• Time in Patent Office: 1,007 Days
• Field of Search: None
• US Class Current: 73/1.38
• CPC Class Codes: G01C 21/185 for gravity
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01P 21/02 of speedometers
• CPC Class Codes: G01P 7/00 Measuring speed by integrating acceleration measuring travelled distance by double integration of acceleration G01C21/16

Abstract

An apparatus for correcting an inertial sensor includes an inertial sensor module, a storage module and a control module. The inertial sensor module measures angular velocity and acceleration of an object moving in a space. The storage module stores predetermined operation information and parameters required to correct the measured acceleration. The control module calculates motion velocity from the measured acceleration using the operation information and the parameters, and corrects the calculated motion velocity for each interval between zero-angular-velocity time instances at which angular velocity about an arbitrary axis is “0”.

Claims

1. A method of correcting an inertial sensor, the method comprising:

measuring an angular velocity and an acceleration of a moving object;

extracting zero-angular-velocity time instances at which the measured angular velocity is “

0”

;

calculating motion velocity from the measured acceleration; and

correcting the calculated motion velocity for each interval between the zero-angular-velocity time instances.

2. The inertial sensor correction method according to claim 1, wherein the calculating the motion velocity comprises:

eliminating a gravitational acceleration component from the measured acceleration to extract motion acceleration; and

integrating the motion acceleration to calculate the motion velocity.

3. The inertial sensor correction method according to claim 2, wherein the correcting the calculated motion velocity for each interval between the zero-angular-velocity time instances comprises subtracting a predetermined linear expression for the interval between the zero-angular-velocity time instances from the calculated motion velocity.

4. The inertial sensor correction method according to claim 3, wherein the linear expression is expressed by the following equation:

$l<br><br>\left(t\right)=\frac{v<br><br>\left(t_2\right)-v<br><br>\left(t_1\right)}{t_2-t_1}<br><br>t+\left(v_1-\frac{v<br><br>\left(t_2\right)-v<br><br>\left(t_1\right)}{t_2-t_1}<br><br>t_1\right)$

where t₁ and t₂ denote zero-angular-velocity time instances, and v(t₁) and v(t₂) denote calculated motion velocities at t₁ and t₂.

5. The inertial sensor correction method according to claim 1, further comprising calculating a motion trajectory based on the corrected motion velocity.

6. The inertial sensor correction method according to claim 5, wherein the calculating the motion trajectory comprises:

calculating motion acceleration from the corrected motion velocity; and

calculating a position of the moving object based on the calculated motion acceleration.

7. The inertial sensor correction method according to claim 6, wherein the calculating the position of the moving object comprises performing a double integral on the calculated motion acceleration.

8. A computer-readable recording medium that records a program implementing a method of correcting an inertial sensor, the method comprising:

measuring an angular velocity and an acceleration of a moving object;

extracting zero-angular-velocity time instances at which the measured angular velocity is “

0”

;

calculating motion velocity from the measured acceleration; and

correcting the calculated motion velocity for each interval between the zero-angular-velocity time instances.

9. An apparatus for correcting an inertial sensor, the apparatus comprising:

an inertial sensor module which measures angular velocity and acceleration of a moving object;

a storage module which stores predetermined operation information and parameters required to correct the measured acceleration; and

a control module which calculates motion velocity from the measured acceleration using the operation information and the parameters, and corrects the calculated motion velocity for each interval between zero-angular-velocity time instances at which the measured angular velocity is “

0”

.

10. The inertial sensor correction apparatus according to claim 9, wherein the control module calculates the motion velocity by eliminating a gravitational acceleration component from the measured acceleration.

11. The inertial sensor correction apparatus according to claim 10, wherein the control module corrects the calculated motion velocity by subtracting a predetermined linear expression for the interval between the zero-angular-velocity time instances from the calculated motion velocity.

12. The inertial sensor correction apparatus according to claim 11, wherein the linear expression is expressed by the following equation:

$l<br><br>\left(t\right)=\frac{v<br><br>\left(t_2\right)-v<br><br>\left(t_1\right)}{t_2-t_1}<br><br>t+\left(v_1-\frac{v<br><br>\left(t_2\right)-v<br><br>\left(t_1\right)}{t_2-t_1}<br><br>t_1\right)$

where t₁ and t₂ denote zero-angular-velocity time instances, and v(t₁) and v(t₂) denote calculated motion velocities at t₁ and t₂.

13. The inertial sensor correction apparatus according to claim 9, wherein the control module calculates a motion trajectory based on the corrected motion velocity.

14. The inertial sensor correction apparatus according to claim 13, wherein the control module calculates the motion trajectory by calculating a motion acceleration from the corrected motion velocity, and calculating a position of the moving object based on the calculated motion acceleration.

15. The inertial sensor correction apparatus according to claim 14, wherein the control module calculates the position of the moving object by performing a double integral on the calculated motion acceleration.

16. A method of calculating a motion trajectory of a moving object, comprising:

measuring an angular velocity and an acceleration of the moving object with an inertial sensor;

extracting zero-angular-velocity time instances at which the angular velocity of the moving object is “

0”

;

calculating a motion velocity of the moving object based on the acceleration of the moving object;

correcting the motion velocity of the moving object for each time interval between the zero-angular-velocity time instances;

calculating the motion trajectory of the moving object using the corrected motion velocity.