System and method for providing accurate vehicle positioning using spatial bias techniques

• US 5,555,503 A
• Filed: 11/23/1993
• Issued: 09/10/1996
• Est. Priority Date: 12/11/1989
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Gudat, Adam J., Kyrtsos, Christos T., Stafford, Darrell E., Christensen, Dana A., Friedrich, Douglas W.
• Primary Examiner(s): Park, Collin W.
• Application Number:
  US08/155,374
• Time in Patent Office: 1,022 Days
• Field of Search: 364/449, 364/453, 364/424.02, 364/443, 364/460, 340/988, 340/990, 342/450, 342/451, 342/352, 342/356, 342/357, 342/358, 342/457
• US Class Current: 701/207
• CPC Class Codes: B60W 2050/0075 Automatic parameter input, automatic initialising or calibrating means
• CPC Class Codes: B60W 2556/45 External transmission of data to or from the vehicle
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/27 creating, predicting or correcting ephemeris or almanac data within the receiver
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/46 the supplementary measurement being of a radio-wave signal type
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G01S 19/52 Determining velocity
• CPC Class Codes: G01S 5/009 Transmission of differential positioning data to mobile
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: G05D 1/028 using a RF signal
• CPC Class Codes: G08G 1/202 Dispatching vehicles on the basis of a location, e.g. taxi dispatching

Abstract

A vehicle position determination system and method provide accurate vehicle positioning using a global positioning system. Spatial bias techniques are used to improve positioning accuracy while the vehicle is in the midst of a relatively linear path and is not approaching a drastically nonlinear path. The use of spatial bias techniques is suspended while the vehicle is approaching or in a drastically nonlinear path.

Claims

1. A method for implementing spatial bias techniques in a system that determines the position of a vehicle, comprising the steps of:

(1) receiving navigation signals from a terrestrial positioning system;

(2) computing position estimates of the vehicle using spatial bias techniques and said navigation signals;

(3) if the vehicle approaches a drastic nonlinear path, then ceasing use of said spatial bias techniques; and

(4) computing said position estimates without said spatial bias techniques until the vehicle approaches a relatively linear path.

2. The method of claim 1, wherein said step (1) of using spatial bias techniques comprises:

using an original bias technique to compute a position estimate for the vehicle.

3. The method of claim 1, wherein said step (1) of using spatial bias techniques comprises:

using a parabolic bias technique to compute a position estimate for the vehicle.

4. The method of claim 1, wherein said step (1) of using spatial bias techniques comprises:

using a base residual bias technique to compute a position estimate for the vehicle.

5. A method for determining the position of a vehicle at or near the surface of the Earth using navigation signals received from a terrestrial positioning system, comprising the steps of:

(1) receiving the navigation signals at a reference receiver at a known position;

(2) processing the navigation signals to determine a spatial bias; and

(3) computing the position of the vehicle using said spatial bias only when the vehicle is in the midst of a relatively linear path and is not approaching a drastically nonlinear path.

6. The method of claim 5, wherein said step (2) of processing the navigation signals comprises:

subtracting estimated pseudoranges and a clock bias from actual pseudoranges to compute an original bias.

7. The method of claim 5, wherein said step (2) of processing the navigation signals comprises:

subtracting an associated value on a parabolic model and a clock bias from actual pseudoranges to compute a parabolic bias, said parabolic model constructed over a time period from prior actual pseudoranges, said clock bias being a difference in clock rates between said reference receiver and the terrestrial positioning system.

8. The method of claim 5, wherein said step (2) of processing the navigation signals comprises:

computing an estimated position of said reference receiver;

computing a difference between said estimated position and said known position of said reference receiver to yield a base residual bias.

9. A system for determining the position of a vehicle at or near the surface of the Earth using navigation signals received from a terrestrial positioning system, comprising:

a reference receiver, located at a known position, for receiving the navigation signals;

bias means for computing a spatial bias from said known position and the navigation signals received by said reference receiver; and

a vehicle-based receiver for receiving the navigation signals and computing the position of the vehicle using said spatial bias only when the vehicle is in the midst of a relatively linear path and is not approaching a drastically nonlinear path.

10. The system of claim 9, further comprising:

means for communicating said spatial bias from said reference receiver to said vehicle-based receiver.

11. The system of claim 9, wherein said bias means comprises:

means for subtracting estimated pseudoranges and a clock bias from actual pseudoranges to compute an original bias.

12. The system of claim 9, wherein said bias means comprises:

means for subtracting an associated value on a parabolic model and a clock bias from actual pseudoranges to compute a parabolic bias, said parabolic model constructed over a time period from prior actual pseudoranges, said clock bias being a difference in clock rates between said reference receiver and the terrestrial positioning system.

13. The system of claim 9, further comprising:

means for computing an estimated position of said reference receiver, and wherein said bias means comprises means for computing a difference between said estimated position and said known position of said reference receiver to yield a base residual bias.

14. A method for determining the position of an autonomous mining vehicle in an open pit mine using navigation signals from a terrestrial positioning system:

(1) receiving the navigation signals at a base station located in or near the open pit mine;

(2) processing the navigation signals received at said base station to determine a spatial bias;

(3) communicating said spatial bias to the vehicle;

(4) receiving the navigation signals and said spatial bias at the vehicle;

(5) computing the position of the vehicle from the navigation signals and said spatial bias when the vehicle is in the midst of a relatively linear path and is not approaching a drastically nonlinear path; and

(6) computing the position of the vehicle from the navigation signals without said spatial bias when the vehicle is approaching a drastically nonlinear path and when the vehicle is in a drastically nonlinear path.

15. The method of claim 14, wherein said step (2) of processing the navigation signals comprises:

subtracting an estimated pseudorange and a clock bias from an actual pseudorange to compute an original bias.

16. The method of claim 14, wherein said step (2) of processing the navigation signals comprises:

subtracting an associated value on a parabolic model and a clock bias from an actual pseudorange to compute a parabolic bias, said parabolic model constructed over a time period from prior actual pseudoranges, said clock bias being a difference in clock rates between said base station and the terrestrial positioning system.

17. The method of claim 14, wherein said step (2) of processing said navigation signals comprises:

computing an estimated position of said base station;

computing a difference between said estimated position and said known position of said base station to yield a base residual bias.