Method and system for determining vehicle position

• US 5,452,211 A
• Filed: 08/10/1992
• Issued: 09/19/1995
• Est. Priority Date: 08/10/1992
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Gudat, Adam J., Kyrtsos, Christos T.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US07/927,037
• Time in Patent Office: 1,135 Days
• Field of Search: 364/458, 364/449, 364/444, 364/447, 364/448, 364/459, 364/455, 342/357, 342/450, 342/451, 342/457
• US Class Current: 701/215
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial

Abstract

A system and method for estimating the terrestrial position of a vehicle is provided. The system receives electromagnetic signals from a single satellite and responsively produces successive ranges from the satellite to the vehicle and respective successive positions of the satellite. The vehicle'"'"'s position is determined as a function of the successive ranges and positions.

Claims

1. A system for estimating the terrestrial position of a vehicle using one of a plurality of orbiting satellites, comprising:

means for receiving electromagnetic signals from the one satellite and responsively producing positions of the one satellite and corresponding ranges from said positions of the one satellite to the vehicle;

means for receiving said positions and said corresponding ranges and responsively determining a first pair comprising a range and a corresponding satellite position at a first time, t₁, determining a second pair comprising a range and a corresponding satellite position at a second time, t₂, and determining a third pair comprising a range and a corresponding satellite position at a third time, t₃ ; and

,

means for receiving said first, second and third pairs and responsively determining the position of the vehicle.

2. A system, as set forth in claim 1, including means for determining a fourth pair comprising a range and a corresponding satellite position at a fourth time, t₄, and wherein said position determining means includes means for receiving said fourth pair and wherein the position of the vehicle is a function of said first, second, third, and fourth pairs.

3. A system, as set forth in claim 2, wherein the position of the vehicle corresponds to said fourth time, t₄, and wherein said position determining means includes means for determining the velocity of the vehicle at said first, second, and third times, t₁, t₂, t₃ and wherein the position of the vehicle is a function of said velocity at said first, second, and third times, t₁, t₂, t₃.

4. A system, as set forth in claim 1, wherein said first, second and third times are separated in time by a predetermined sample rate.

5. A system, as set forth in claim 1, wherein the positions of the one satellite are defined in Cartesian coordinates.

6. A system, as set forth in claim 3, including a base station at a known location, said base station including a reference receiver and adapted for determining velocity biases.

7. A system, as set forth in claim 6, wherein said velocity biases are communicated back to the vehicle.

8. A system for estimating the terrestrial position of a vehicle using one of a plurality of orbiting satellites, comprising:

means for receiving electromagnetic signals from the one satellite and responsively producing positions of the one satellite and corresponding ranges from said positions of the one satellite to the vehicle;

means for receiving said positions and said corresponding ranges and responsively determining a first pair comprising a range and a corresponding position at a first time, t₁, determining a second pair comprising a range and a corresponding position at a second time, t₂, and determining a third pair comprising a range and a corresponding position at a third time, t₃ ; and

,

means for receiving said first, second and third pairs and responsively determining a first position estimate of the vehicle;

means for producing a second position estimate, said second position estimate producing means including an odometer and an inertial reference unit; and

,

means for receiving said first and second position estimates and responsively producing a third position estimate.

9. A system, as set forth in claim 8, wherein said first position estimate producing means includes a Kalman filter.

10. A system, as set forth in claim 8, wherein said third position estimate producing means includes a Kalman filter.

11. A system, as set forth in claim 8, wherein said third position estimate producing means includes a weighted combiner.

12. A system, as set forth in claim 8, wherein said third position estimate producing means includes a Kalman filter and a weighted combiner.

13. A system, as set forth in claim 8, including means for determining a fourth pair comprising a range and a corresponding satellite position at a fourth time, t₄ and wherein said position determining means includes means for receiving said fourth pair and wherein the position of the vehicle is a function of said first, second, third, and fourth pairs.

14. A system, as set forth in claim 13, wherein the position of the vehicle corresponds to said fourth time, t₄, and wherein said position determining means includes means for determining the velocity of the vehicle at said first, second, and third times, t₁, t₂, t₃ and wherein the position of the vehicle is a function of said velocity at said first, second and third times, t₁, t₂, t₃.

15. A system, as set forth in claim 14, including a base station at a known location, said base station including a reference receiver and adapted for determining velocity biases.

16. A system for estimating the terrestrial position of a vehicle using one of a plurality of orbiting satellites, comprising:

means for receiving electromagnetic signals from the one satellite and responsively producing a first position estimate;

means for producing a second position estimate, said second position estimate producing means including an odometer and an inertial reference unit; and

,

means for receiving said first and second position estimates and responsively producing a third position estimate; and

wherein said first position estimate producing means includes;

an antenna for receiving said electromagnetic signals;

a receiver coupled to said antenna and being adapted to produce positions of the one satellite and corresponding ranges from said positions of the one satellite to the vehicle; and

,

a processor adapted to receive said positions and said corresponding ranges and responsively determine a first pair comprising a range and a corresponding position at a first time, t₁, determine a second pair comprising a range and a corresponding position at a second time, t₂, and determine a third pair comprising a range and a corresponding position at a third time, t₃ and including means for determining said first position estimate as a function of said first, second and third pairs.

17. A system, as set forth in claim 16, including means for determining a fourth pair comprising a range and a corresponding satellite position at a fourth time, t₄ and wherein said position determining means includes means for receiving said fourth pair and wherein the position of the vehicle is a function of said first, second, third, and fourth pairs.

18. A system, as set forth in claim 17, wherein said position of the vehicle corresponds to said fourth time, t₄, and wherein said position determining means includes means for determining the velocity of the vehicle at said first, second, and third times, t₁, t₂, t₃ and wherein the position of the vehicle is a function of said velocity at said first, second, and third times, t₁, t₂, t₃.

19. A method for estimating the position of a vehicle using one of a plurality of orbiting satellites, including:

receiving electromagnetic signals from the one satellite and responsively producing positions of the one satellite and corresponding ranges from said positions of the one satellite to the vehicle;

receiving said positions and said corresponding ranges and responsively determining a first pair comprising a range and a corresponding position at a first time, t₁ ;

receiving said positions and said corresponding ranges and responsively determining a second pair comprising a range and a corresponding position at a second time, t₂ ;

receiving said positions and said corresponding ranges and responsively determining a third pair comprising a range and a corresponding position at a third time, t₃ ; and

,

receiving said first, second and third pairs and responsively determining a position estimate of the vehicle.

20. A method, as set forth in claim 19, including the step of:

receiving said positions and said corresponding ranges and responsively determining a fourth pair comprising a range and a corresponding position at a fourth time, t₄ ;

wherein said positioning determining step includes the step of;

receiving the fourth pair;

and wherein the position of the vehicle is determined as a function of the fourth pair.

21. A method, as set forth in claim 20, including the steps of:

determining the velocity of the vehicle at said first time, t₁ ;

determining the velocity of the vehicle at said second time, t₂ ;

determining the velocity of the vehicle at said third time, t₃ ;

and wherein the position of the vehicle is determined as a function of the vehicle'"'"'s velocity at said first, second, and third times, t₁, t₂, t₃.

22. A method for estimating the position of a vehicle using one of a plurality of orbiting satellites, including:

receiving electromagnetic signals from the one satellite and responsively producing positions of the one satellite and corresponding ranges from said positions of the one satellite to the vehicle;

receiving said positions and said corresponding ranges and responsively determining a first pair comprising a range and a corresponding position at a first time, t₁ ;

receiving said positions and said corresponding ranges and responsively determining a second pair comprising a range and a corresponding position at a second time, t₂ ;

receiving said positions and said corresponding ranges and responsively determining a third pair comprising a range and a corresponding position at a third time, t₃ ; and

,

receiving said first, second and third pairs and responsively determining a first position estimate of the vehicle.

receiving signals from an odometer and an inertial reference unit and responsively producing a second position estimate; and

,

receiving said first and second position estimate and responsively producing a third position estimate.