Position calculating method and position calculating device

• US 9,026,362 B2
• Filed: 05/02/2012
• Issued: 05/05/2015
• Est. Priority Date: 05/10/2011
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kumar, Anand, Mizuochi, Shunichi, Onda, Kenji, Sanjay, Rama
• Primary Examiner(s): Dager, Jonathan M
• Application Number:
  US14/116,750
• Publication Number:
  US 20140214317A1
• Time in Patent Office: 1,098 Days
• Field of Search: None
• US Class Current: 701/469
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01S 19/05 providing aiding data
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial

Abstract

In a position calculating device, a first operational process of calculating at least a position of a moving object using the measurement result of an inertial positioning unit disposed in the moving object is performed by a first operation processing unit. A second operational process of calculating the position of the moving object using the result of the first operational process and the measurement result of a satellite positioning unit disposed in the moving object is performed by a second operation processing unit. An operational coefficient of the first operational process is adjusted using the result of the first operational process and the result of the second operational process by an operational coefficient adjusting unit.

Claims

1. A position calculating method comprising:

performing a first operational process of calculating at least a position of a moving object using the measurement result of an inertial positioning unit disposed in the moving object;

performing a second operational process of calculating the position of the moving object using the result of the first operational process and the measurement result of a satellite positioning unit disposed in the moving object; and

adjusting an operational coefficient of the first operational process using the result of the first operational process and the result of the second operational process,

wherein the measurement result of the inertial positioning unit includes an inertial positioning position,

wherein the first operational process includes a predetermined error estimating operation of estimating a first position error included in a calculated first operational position,

wherein the adjusting of the operational coefficient includes;

estimating an inertial positioning error included in the inertial positioning position using the first position error and a second operational position calculated in the second operational process; and

adjusting the operational coefficient using the inertial positioning error, and wherein the estimating of the inertial positioning error includes;

calculating a difference between the inertial positioning position and the second operational position; and

calculating the inertial positioning error by averaging the first position error and the difference.

2. The position calculating method according to claim 1, wherein the averaging process is a process of setting weights of the first position error and the difference on the basis of one or both of a positioning environment and reliability of the measurement result of the satellite positioning unit and performing a weighted averaging operation.

3. The position calculating method according to claim 1, wherein the measurement result of the inertial positioning unit includes an inertial positioning position, and

wherein the first operational process is a Kalman filtering process using the inertial positioning position as an input.

4. The position calculating method according to claim 3, wherein the measurement result of the satellite positioning unit includes a velocity, and

wherein the Kalman filtering process is a process using the velocity as an observable.

5. The position calculating method according to claim 1, wherein the measurement result of the satellite positioning unit includes a satellite positioning position, and

wherein the second operational process is a Kalman filtering process using the result of the first operational process as an input and using the satellite positioning position as an observable.

6. A position calculating device comprising:

a first operation processing unit that performs a first operational process of calculating at least a position of a moving object using the measurement result of an inertial positioning unit disposed in the moving object;

a second operation processing unit that performs a second operational process of calculating the position of the moving object using the result of the first operational process and the measurement result of a satellite positioning unit disposed in the moving object; and

an adjustment unit that adjusts an operational coefficient of the first operational process using the result of the first operational process and the result of the second operational process,

wherein the measurement result of the inertial positioning unit includes an inertial positioning position,

wherein the first operational process includes a predetermined error estimating operation of estimating a first position error included in a calculated first operational position,

wherein adjusting of the operational coefficient includes;

estimating an inertial positioning error included in the inertial positioning position using the first position error and a second operational position calculated in the second operational process; and

adjusting the operational coefficient using the inertial positioning error, and wherein the estimating of the inertial positioning error includes;

calculating a difference between the inertial positioning position and the second operational position; and

calculating the inertial positioning error by averaging the first position error and the difference.