Zero-Point Correction Apparatus and Method for an Angular Speed Sensor

• US 20100106451A1
• Filed: 08/01/2006
• Published: 04/29/2010
• Est. Priority Date: 08/01/2005
• Status: Abandoned Application

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nonomura, Yataka, Sugihara, Hisayoshi, Fujiyoshi, Motohiro
• Application Number:
  US11/989,710
• Publication Number:
  US 20100106451A1
• Time in Patent Office: Days
• US Class Current: 702/147
• CPC Class Codes: G01C 25/005 initial alignment, calibration or starting-up of inertial devices
• CPC Class Codes: G01P 13/00 Indicating or recording presence, absence, or direction, of movement electric switches H01H; counting moving objects G06M7/00

Abstract

An angular sensor (10) is provided in a mobile body. A first setter (14) performs determination regarding the standstill state on the basis of whether or not the variation width of the angular speed is less than or equal to a predetermined value. A standstill determiner (20) determines whether or not the standstill state has continued beyond a determination time. An n−i sum-total averaging unit (34) calculates a sum-total average of (n−i) number of pieces of data obtained by excluding, from n number of pieces of data input during a period determined as a continuation of the standstill state, i number of pieces of data that are output immediately before the end timing of the period, and determines it as a zero-point offset. A zero-point corrector (36) performs the zero-point correction of the output value of the angular speed sensor (10), and outputs the corrected value to an output unit (28).

Claims

1. A zero-point correction apparatus of an angular speed sensor provided in a mobile body, comprising:

detection means for detecting a standstill state of the mobile body;

calculation means for calculating an average value of output values of the angular speed sensor during the standstill state; and

correction means for correcting a zero point of the angular speed sensor to the average value.

2. The apparatus according to claim 1, wherein the calculation means calculates an average value of output values of the angular speed sensor during a period from a start timing of the standstill state till a time point earlier than an end timing of the standstill state.

3. The apparatus according to claim 2, further comprising means for variably setting the predetermined time.

4. The apparatus according to claim 1, wherein the calculation means calculates an average value of output values of the angular speed sensor that are obtained by excluding a predetermined number of output values that are output immediately before an end timing of the standstill sate from output values that are output during a period from a start timing of the standstill state till the end timing of the standstill state.

5. The apparatus according to claim 4, further comprising means for variably setting the predetermined number of output values.

6. The apparatus according to any one of claims 1 to 5, wherein the detection means detects the standstill state based on whether or not a variation width of output values of the angular speed sensor is less than or equal to a first predetermined width.

7. The apparatus according to any one of claims 1 to 5, wherein the detection means detects the standstill state based on whether or not a variation width of output values of an acceleration sensor provided in the mobile body is less than or equal to a second predetermined width.

8. The apparatus according to any one of claims 1 to 5, wherein the detection means detects the standstill state based on whether or not a variation width of output values of the angular speed sensor is less than or equal to a first predetermined width and a variation width of output values of an acceleration sensor provided in the mobile body is less than or equal to a second predetermined value.

9. The apparatus according to claim 7 or 8, wherein the detection means detects the standstill state based on whether or not an absolute value of an output value of the acceleration sensor is substantially equal to a gravitational acceleration.

10. The apparatus according to any one of claims 6 to 9, further comprising means for variably setting at least one of the first predetermined width and the second predetermined width.

11. The apparatus according to any one of claims 1 to 10, wherein the detection means detects the standstill state that continues for at least a predetermined determination time.

12. The apparatus according to claim 11, further comprising means for variably setting the predetermined determination time.

13. A zero-point correction method of an angular speed sensor provided in a mobile body, comprising:

determining whether the mobile body is in a standstill state;

calculating an average value of output values of the angular speed sensor during the standstill state; and

correcting a zero point of the angular speed sensor to the average value.

14. A zero-point correction apparatus of an angular speed sensor provided in a mobile body, comprising:

a detector that detects a standstill state of the mobile body; and

a controller that calculates an average value of output values of the angular speed sensor during the standstill state and corrects a zero point of the angular speed sensor to the average value.