Method and apparatus for correcting output sensitivity, and navigation system

• US 5,974,359 A
• Filed: 07/30/1997
• Issued: 10/26/1999
• Est. Priority Date: 08/13/1996
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ohkubo, Masashi
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): Hernandez, Olga
• Application Number:
  US08/903,289
• Time in Patent Office: 818 Days
• Field of Search: 701/214, 701/216, 701/217, 701/221, 364/443, 364/444, 364/449, 364/453, 364/454, 364/449.8, 342/357, 250/561, 324/166
• US Class Current: 701/214
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments
• CPC Class Codes: G01S 19/52 Determining velocity

Abstract

A method for correcting the output sensitivity an angular velocity detector, in which, a first running directional data of the mobile object is successively calculated in accordance with the output signal of the angular velocity detector, a second running directional data of the mobile object is successively calculated in accordance with the positioning data obtained from a plurality satellites, the sensitivity correction coefficient is calculated in based on the stored first and second running directional data, and the sensitivity correction coefficient is multiplexed by the output signal of the angular velocity detector, so as to correct the output sensitivity of the angular velocity detector. Therefore, the dispersion of the output sensitivity of the angular velocity detector is eliminated to improve the accuracy of output sensitivity.

Claims

1. A method for correcting an output sensitivity of an angular velocity detector which detects running directional data of a mobile object, comprising the steps of:

successively calculating first running directional data of said mobile object in accordance with an output signal of said angular velocity detector;

successively calculating second running directional data of said mobile object in accordance with positioning data obtained from a plurality of satellites;

storing said first and second running directional data of said mobile object;

calculating a sensitivity correction coefficient in accordance the stored first and second running direction data;

reducing said sensitivity correction coefficient when a first difference parameter and a second difference parameter are both plus or are both minus; and

increasing said sensitivity correction coefficient in all other cases, wherein said first difference parameter is a difference between values corresponding to most recent first running directional data and previous first running direction data and said second difference parameter is a difference between first differential data and second differential data, said first differential data being a difference between values corresponding to most recent first running directional data and most recent second running directional data, and said second differential data being a difference between previous first running directional data and previous second running directional data; and

multiplying the calculated sensitivity correction coefficient by the output signal of said angular velocity detector so as to correct the output sensitivity of said angular velocity detector.

2. The method for correcting the output sensitivity according to claim 1, further comprising a step of:

detecting a velocity of said mobile object, wherein

said sensitivity correction coefficient is calculated when the detected velocity of said mobile object exceeds a predetermined velocity.

3. The method for correcting the output sensitivity according to claim 1, wherein;

said sensitivity correction coefficient is calculated when said first difference parameter, which is calculated based on most recent data and previous data of said first running directional data of said mobile object, exceeds a predetermined value.

4. The method for correcting the output sensitivity according to claim 1, wherein

said plurality of satellites are global positioning system (GPS) satellites.

5. An apparatus for correcting an output sensitivity of an angular velocity detector that successively outputs first running directional data of a mobile object, the apparatus comprising:

a GPS receiver for successively outputting second running direction data of said mobile object in accordance with positioning data obtained from a plurality of satellites;

storing means for storing said first and second running directional data of said mobile object; and

control means for calculating a sensitivity correction coefficient in accordance with said first and second running directional data from said storing means and for multiplying the sensitivity correction coefficient by an output signal of said angular velocity detector, so as to correct the output sensitivity of said angular velocity detector, wherein

said control means reduces said sensitivity correction coefficient when a first difference parameter and a second difference parameter are both plus or are both minus, and

said control means increases said sensitivity correction coefficient in all other cases, wherein said first difference parameter is a difference between values corresponding to most recent first running directional data and previous first running directional data and said second difference parameter is a difference between first differential data and second differential data, said first differential data being a difference between the values corresponding to most recent first running directional data and most recent second running directional data, and said second differential data being a difference between previous first running directional data and previous second running directional data.

6. The apparatus for correcting the output sensitivity of the angular velocity detector according to claim 5, wherein

said control means calculates said sensitivity correction coefficient when a velocity of said mobile object exceeds a predetermined velocity.

7. The apparatus for correcting the output sensitivity of the angular velocity detector according to claim 5, wherein;

said control means calculates said sensitivity correction coefficient when, said first difference parameter which is calculated based on most recent data and previous data of said first running directional data of said mobile object, exceeds a predetermined value.