Vehicle self-carried positioning method and system thereof

• US 6,738,714 B2
• Filed: 02/18/2003
• Issued: 05/18/2004
• Est. Priority Date: 11/29/1999
• Status: Expired due to Term

• Current Assignee: American GNC Corporation
• Original Assignee: American GNC Corporation
• Inventors: McCall, Hiram, Lin, Ching-Fang
• Primary Examiner(s): Marc-Coleman, Marthe Y.
• Application Number:
  US10/370,130
• Publication Number:
  US 20030158665A1
• Time in Patent Office: 455 Days
• Field of Search: 701/220, 701/221, 701/207, 701/217, 731/78.R, 734/30, 342/357.14, 342/357.01, 342/357.05, 340/995, 340/988
• US Class Current: 701/220
• CPC Class Codes: G01C 21/188 for accumulated errors, e.g. by coupling inertial systems with absolute positioning systems

Abstract

A vehicle self-carried positioning system, carried in a vehicle, includes an inertial measurement unit, a north finder, a velocity producer, a navigation processor, a wireless communication device, and a display device and map database. Output signals of the inertial measurement unit, the velocity producer, and the north finder are processed to obtain highly accurate position measurements of a vehicle on land and in water, and the vehicle position information can be exchanged with other users through the wireless communication device, and the location and surrounding information can be displayed on the display device by accessing a map database with the vehicle position information.

Claims

1. A vehicle self-carried positioning system for being carried in a vehicle, comprising:

an inertial measurement unit sensing traveling displacement motions of said vehicle and producing digital angular increments and velocity increments signals in response to said traveling displacement motions of said vehicle;

a north finder producing a heading measurement of said vehicle;

a velocity producer producing a current axis velocity data of a body frame of said vehicle; and

a navigation processor, which is connected with said inertial measurement unit, said north finder, and said velocity producer so as to receive said digital angular increments and velocity increments signals, heading measurement, and current axis velocity data of said body frame, for

comparing an inertial measurement unit (IMU) position deduced from said digital angular increments and velocity increments signals with a measured position deduced from said heading measurement and current axis velocity data of said body frame, so as to obtain a position difference; and

feeding back said position difference to correct said IMU position to output a corrected IMU position when said position difference is bigger than a predetermined scale value.

2. The vehicle self-carried positioning system, as recited in claim 1, wherein said north finder is a magnetic sensor detecting a magnetic field vector of the earth to form said magnetic heading measurement.

3. The vehicle self-carried positioning system, as recited in claim 2, further comprising a wireless communication device for exchanging said IMU position and said corrected IMU position with other vehicle self-carried positioning systems carried by other vehicles.

4. The vehicle self-carried positioning system, as recited in claim 3, further comprising a map database and a display device for displaying a location of said vehicle on a map and obtaining surrounding information by accessing said map database using said IMU position and said corrected IMU position.

5. The vehicle self-carried positioning system, as recited in claim 2, further comprising a map database and a display device for displaying a location of said vehicle on a map and obtaining surrounding information by accessing said map database using said IMU position and said corrected IMU position.

6. The vehicle self-carried positioning-system, as recited in claim 1, further comprising a wireless communication device for exchanging said IMU position and said corrected IMU position with other vehicle self-carried positioning systems carried by other vehicles.

7. The vehicle self-carried positioning system, as recited in claim 3, further comprising a map database and a display device for displaying a location of said vehicle on a map and obtaining surrounding information by accessing said map database using said IMU position and said corrected IMU position.

8. The vehicle self-carried positioning system, as recited in claim 1, further comprising a map database and a display device for displaying a location of said vehicle on a map and obtaining surrounding information by accessing said map database using said IMU position and said corrected IMU position.

9. The vehicle self-carried positioning system, as recited in claim 1, wherein said navigation processor further comprises:

an INS computation module, using said digital angular increments and velocity increments signals from said inertial measurement unit to produce inertial positioning measurements;

a magnetic sensor processing module for producing a heading angle;

a vehicle producer processing module for producing relative position error measurements for a Kalman filter; and

a Kalman filter module for estimating errors of said inertial positioning measurements to calibrate inertial positioning measurement errors.

10. The vehicle self-carried positioning system, as recited in claim 9, wherein said INS computation module further comprises:

a sensor compensation module for calibrating errors of said digital angular increments and velocity increments signals; and

an inertial navigation algorithm module for computing IMU position, velocity and attitude data.

11. A vehicle self-carried positioning system for being carried in a vehicle, comprising:

a north finder producing a heading measurement of said vehicle;

a velocity producer producing a current axis velocity data of a body frame of said vehicle; and

a micro inertial measurement unit sensing traveling displacement motions of said vehicle and producing digital angular increments and velocity increments signals in response to said traveling displacement motions of said vehicle;

wherein micro inertial measurement unit comprises an angular rate producer producing X axis, Y axis and Z axis angular rate electrical signals, an acceleration producer producing X axis, Y axis and Z axis acceleration electrical signals, and an angular increment and velocity increment producer converting said X axis, Y axis and Z axis angular rate electrical signals into digital angular increments and converting said input X axis, Y axis and Z axis acceleration electrical signals into digital velocity increments; and

a navigation processor, which is connected with said inertial measurement unit, said north finder, and said velocity producer so as to receive said digital angular increments and velocity increments signals, heading measurement, and current axis velocity data of said body frame.

12. A vehicle self-carried positioning method, comprising the steps of:

(a) sensing traveling displacement motions of a vehicle and producing digital angular increments and velocity increments signals in response to said traveling displacement motions by an inertial measurement unit;

(b) sensing magnetic field of the earth to measure a heading angle of said vehicle by a north finder;

(c) measuring a relative velocity of said vehicle relative to a transportation surface where said vehicle moving thereon by a velocity producer, and

(d) deducing position data in an integration processor, using said digital angular increments and velocity increments signals, said heading angle, said relative velocity of said vehicle relative to said transportation surface.

13. The vehicle self-carried positioning method, as recited in claim 12, wherein the step (d) further comprises the steps of:

(d.1) computing inertial positioning measurements using said digital angular increments and velocity increments signals;

(d.2) computing said heading angle using said earth'"'"'s magnetic field measurements;

(d.3) creating a relative position error measurement in a velocity producer processing module of said navigation processor using said relative velocity of said vehicle relative to said transportation surface for a Kalman filter;

(d.4) creating a relative position error measurement in said velocity producer processing module using said relative velocity of said user relative to said water for said Kalman filter; and

(d.5) estimating errors of said inertial positioning measurements to calibrate inertial positioning measurement errors.

14. The vehicle self-carried positioning method, as recited in claim 13, after the step (d), further comprising a first additional processing step of exchanging obtained position information with other vehicles via a wireless communication device.

15. The vehicle self-carried positioning method, as recited in claim 14, further comprising a second additional processing step of displaying a location of said vehicle on a map and displaying surrounding information by accessing said map database using obtained position information.

16. The vehicle self-carried positioning method, as recited in claim 13, further comprising an additional processing step of displaying a location of said vehicle on a map and displaying surrounding information by accessing said map database using obtained position information.

17. The vehicle self-carried positioning method, as recited in claim 12, after the step (d), further comprising an additional processing step of exchanging obtained position information with other vehicles via a wireless communication device.

18. The vehicle self-carried positioning method, as recited in claim 14, further comprising a second additional processing step of displaying a location of said vehicle on a map and displaying surrounding information by accessing said map database using obtained position information.

19. The vehicle self-carried positioning method, as recited in claim 12, further comprising an additional processing step of displaying a location of said vehicle on a map and displaying surrounding information by accessing said map database using obtained position information.