Method of and apparatus for detecting angular velocity, method of and apparatus for detecting angel, navigation system, program storage device, and computer data signal embodied in carrier wave

• US 20020165687A1
• Filed: 05/03/2002
• Published: 11/07/2002
• Est. Priority Date: 05/07/2001
• Status: Active Grant

• Current Assignee: Pioneer Corporation
• Original Assignee: Pioneer Corporation
• Inventors: Imada, Seiji, Goto, Seiji, Endo, Isao
• Granted Patent: US 6,757,631 B2
• Time in Patent Office: Days
• US Class Current: 702/146
• CPC Class Codes: G01C 21/28 with correlation of data from several navigational instruments

Abstract

A method of detecting an angle is provided with processes of: setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor (12) under a predetermined condition; and calculating the angle on the basis of a difference between the output voltage and the set or updated standard voltage. It is further provided with processes of storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data; estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage; and correcting the calculated angle on the basis of a difference between a value of the standard voltage used in the calculation process and the estimated value of the bias voltage.

Claims

1. A method of detecting an angular velocity comprising processes of:

setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor in response to an angular velocity when a predetermined condition is satisfied as well as updating the standard voltage every time the predetermined condition is satisfied;

calculating the angular velocity on the basis of the output voltage with using the set or updated standard voltage as a standard;

storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

correcting the angular velocity calculated by said calculating process on the basis of a difference between a value of the standard voltage used in said calculating process and the estimated value of the bias voltage.

2. A method according to claim 1, further comprising a process of judging whether or not the predetermined condition is satisfied, wherein said setting process sets or updates the standard voltage depending on a judgment result in said judging process.

3. A method according to claim 1, wherein said estimating process uses an n function (n is a natural number), which approximates a change of the bias voltage value with respect to time, as the function.

4. A method of detecting an angle comprising processes of:

setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor mounted on a movable thing in response to an angular velocity when a predetermined condition is satisfied, as well as updating the standard voltage every time the predetermined condition is satisfied;

calculating the angle of the movable thing on the basis of a difference between the output voltage and the set or updated standard voltage;

storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

correcting the angle calculated by said calculating process on the basis of a difference between a value of the standard voltage used in said calculating process and the estimated value of the bias voltage.

5. A method according to claim 4, further comprising a process of judging whether or not the predetermined condition is satisfied, wherein said setting process sets or updates the standard voltage depending on a judgment result in said judging process.

6. A method according to claim 4, wherein said estimating process uses an n function (n is a natural number), which approximates a change of the bias voltage value with respect to time, as the function.

7. A method according to claim 4, wherein

said calculating process converts a value, which is obtained by integrating on a time axis a difference between the output voltage and the set or updated standard voltage, to a turning angle of the movable thing, and

said correcting process corrects the angle by correcting the turning angle in response to a value, which is obtained by integrating on a time axis a difference between the value of the standard voltage used in said calculating process and the estimated value of the bias voltage.

8. An apparatus for detecting an angular velocity comprising:

a setting device for setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor in response to an angular velocity when a predetermined condition is satisfied as well as updating the standard voltage every time the predetermined condition is satisfied;

a calculating device for calculating the angular velocity on the basis of the output voltage with using the set or updated standard voltage as a standard;

a storing device for storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

an estimating device for estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

a correcting device for correcting the angular velocity calculated by said calculating device on the basis of a difference between a value of the standard voltage used in said calculating device and the estimated value of the bias voltage.

9. An apparatus according to claim 8, further comprising a judging device for judging whether or not the predetermined condition is satisfied,

wherein said setting device sets or updates the standard voltage depending on a judgment result in said judging device.

10. An apparatus according to claim 8, wherein said estimating device uses an n function (n is a natural number), which approximates a change of the bias voltage value with respect to time, as the function.

11. An apparatus for detecting an angle comprising:

a setting device for setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor mounted on a movable thing in response to an angular velocity when a predetermined condition is satisfied as well as updating the standard voltage every time the predetermined condition is satisfied;

a calculating device for calculating the angle of the movable thing on the basis of a difference between the output voltage and the set or updated standard voltage;

a storing device for storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

an estimating device for estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

a correcting device for correcting the angle calculated by said calculating device on the basis of a difference between a value of the standard voltage used in said calculating device and the estimated value of the bias voltage.

12. An apparatus according to claim 11, further comprising a judging device for judging whether or not the predetermined condition is satisfied,

wherein said setting device sets or updates the standard voltage depending on a judgment result in said judging device.

13. An apparatus according to claim 11, wherein said estimating device uses an n function (n is a natural number), which approximates a change of the bias voltage value with respect to time, as the function.

14. An apparatus according to claim 11, wherein

said calculating device converts a value, which is obtained by integrating on a time axis a difference between the output voltage and the set or updated standard voltage to a turning angle of the movable thing, and

said correcting device corrects the angle by correcting the turning angle in response to a value, which is obtained by integrating on a time axis a difference between the value of the standard voltage used in said calculating device and the estimated value of the bias voltage.

15. A navigation system comprising

(i) an apparatus for detecting an angle comprising:

a setting device for setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor mounted on a movable thing in response to an angular velocity when a predetermined condition is satisfied as well as updating the standard voltage every time the predetermined condition is satisfied;

a calculating device for calculating the angle of the movable thing on the basis of a difference between the output voltage and the set or updated standard voltage;

a storing device for storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

an estimating device for estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

a correcting device for correcting the angle calculated by said calculating device on the basis of a difference between a value of the standard voltage used in said calculating device and the estimated value of the bias voltage,

(ii) the angular velocity sensor, and

(iii) a displaying device for displaying the corrected angle in a predetermined format.

16. A program storage device readable by a computer, tangibly embodying a program of instructions executable by the computer to perform method processes of detecting an angle of a movable thing,

said method processes comprising:

setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor mounted on a movable thing in response to an angular velocity when a predetermined condition is satisfied, as well as updating the standard voltage every time the predetermined condition is satisfied;

calculating the angle of the movable thing on the basis of a difference between the output voltage and the set or updated standard voltage;

storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

correcting the angle calculated by said calculating process on the basis of a difference between a value of the standard voltage used in said calculating process and the estimated value of the bias voltage.

17. A program storage device readable by a computer, tangibly embodying a program of instructions executable by the computer to perform method processes of detecting an angular velocity of a movable thing,

said method processes comprising:

setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor in response to an angular velocity when a predetermined condition is satisfied as well as updating the standard voltage every time the predetermined condition is satisfied;

calculating the angular velocity on the basis of the output voltage with using the set or updated standard voltage as a standard;

storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

correcting the angular velocity calculated by said calculating process on the basis of a difference between a value of the standard voltage used in said calculating process and the estimated value of the bias voltage.

18. A computer data signal embodied in a carrier wave and representing a series of instructions which cause a computer to perform method processes of detecting an angle of a movable thing,

said method processes comprising:

setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor mounted on a movable thing in response to an angular velocity when a predetermined condition is satisfied, as well as updating the standard voltage every time the predetermined condition is satisfied;

calculating the angle of the movable thing on the basis of a difference between the output voltage and the set or updated standard voltage;

storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

correcting the angle calculated by said calculating process on the basis of a difference between a value of the standard voltage used in said calculating process and the estimated value of the bias voltage.

19. A computer data signal embodied in a carrier wave and representing a series of instructions which cause a computer to perform method processes of detecting an angular velocity of a movable thing,

said method processes comprising:

setting a bias voltage, as a standard voltage, which is an output voltage outputted from an angular velocity sensor in response to an angular velocity when a predetermined condition is satisfied as well as updating the standard voltage every time the predetermined condition is satisfied;

calculating the angular velocity on the basis of the output voltage with using the set or updated standard voltage as a standard;

storing time data, which indicate a time of setting or updating the standard voltage, in correspondence with standard voltage data, which indicate a value of the set or updated standard voltage;

estimating a value of the bias voltage of the angular velocity sensor at each time between times of setting or updating the standard voltage, as a function of time, on the basis of a plurality of the stored standard voltage data and a plurality of the stored time data; and

correcting the angular velocity calculated by said calculating process on the basis of a difference between a value of the standard voltage used in said calculating process and the estimated value of the bias voltage.