Positioning system implementing multi-sensor pose solution

• US 9,494,430 B2
• Filed: 10/27/2014
• Issued: 11/15/2016
• Est. Priority Date: 10/27/2014
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Vogel, Nicholas Robert, Friend, Paul Russell, Chen, Qi, Whitten, Andrew Thomas
• Primary Examiner(s): PATEL, SHARDUL D
• Application Number:
  US14/524,727
• Publication Number:
  US 20160116289A1
• Time in Patent Office: 750 Days
• Field of Search: 701/28, 701/41, 701/469, 414/335, 702/104, 382/104
• US Class Current: 1/1
• CPC Class Codes: G01C 21/165 combined with non-inertial navigation instruments
• CPC Class Codes: G01C 21/1652 with ranging devices, e.g. LIDAR or RADAR
• CPC Class Codes: G01C 21/1654 with electromagnetic compass
• CPC Class Codes: G01S 19/393 Trajectory determination or predictive tracking, e.g. Kalman filtering
• CPC Class Codes: G01S 19/396 Determining accuracy or reliability of position or pseudorange measurements
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G01S 19/53 Determining attitude
• CPC Class Codes: G01S 5/0247 Determining attitude

Abstract

A system for determining the position of a mobile machine is disclosed. The system may include a first sensor configured to generate a first signal indicative of a pose of the mobile machine, a second sensor configured to generate a second signal indicative of a parameter of the mobile machine, and a controller in communication with the first and second sensors. The controller may be configured to generate a measured pose of the mobile machine based on the first signal, to generate an estimated pose of the mobile machine based on the second signal, and to determine uncertainty values associated with each of the measured and estimated poses. The controller may be further configured to determine overlap of the uncertainty values, to selectively adjust the measured pose based on the overlap, and to determine a pose solution based on the estimated pose and adjustment of the measured pose.

Claims

1. A positioning system for use with a mobile machine, comprising:

a first sensor configured to generate a first signal indicative of a pose of the mobile machine;

a second sensor configured to generate a second signal indicative of a parameter of the mobile machine; and

a controller in communication with the first and second sensors, the controller configured to;

receive a first pose solution from a memory location;

generate a measured pose of the mobile machine based on the first signal;

generate an estimated pose of the mobile machine based on the first pose solution and the second signal;

determine uncertainty values associated with each of the measured and estimated poses;

determine an overlap of the uncertainty values;

selectively adjust the measured pose and uncertainty value based on the overlap; and

determine a second pose solution based on the estimated pose and adjustment of the measured pose and uncertainty value.

2. The positioning system of claim 1, wherein the controller determines the second pose solution based on the estimated pose and adjustment of the measured pose and uncertainty value only when the estimated and measured poses are generally synchronous.

3. The positioning system of claim 2, wherein the controller is further configured to selectively determine the second pose solution based on only the estimated pose when the estimated and measured poses are not generally synchronous and the uncertainty values do not overlap.

4. The positioning system of claim 3, wherein the second pose solution passes through a center of the estimated pose when the estimated and measured poses are not generally synchronous and the uncertainty values do not overlap.

5. The positioning system of claim 1, wherein the controller is configured to adjust the measured pose and uncertainty value_only when the uncertainty values overlap and the overlap is less than a threshold %.

6. The positioning system of claim 1, wherein the controller is further configured to determine a difference between the measured pose as adjusted and the estimated pose, and to perform a Kalman filter update to determine the second pose solution.

7. The positioning system of claim 1, wherein the controller is configured to adjust the measured pose and uncertainty value by moving the measured pose toward the estimated pose and increasing a size of the uncertainty value associated with the measured pose to encompass an original uncertainty value associated with the measured pose and the estimated pose.

8. The positioning system of claim 1, wherein the controller is configured to adjust the measured pose and uncertainty value by moving the measured pose toward the estimated pose and increasing a size of the uncertainty value associated with the measured pose to encompass an original uncertainty value associated with the measured pose and an original uncertainty value associated with the estimated pose.

9. The positioning system of claim 1, wherein the controller is configured to adjust the measured pose and uncertainty value by only increasing a size of the uncertainty value associated with the measured pose to encompass an original uncertainty value associated with the measured pose and the estimated pose.

10. The positioning system of claim 1, wherein the first sensor is a GNSS receiver.

11. The positioning system of claim 10, wherein the second sensor is an IMU.

12. The positioning system of claim 1, wherein the parameter includes at least one of an acceleration, a velocity, a heading, and an angular rate.

13. The positioning system of claim 1, wherein the controller is further configured to selectively initialize the second pose solution with the measured pose when the mobile machine is stationary.

14. The positioning system of claim 1, wherein the controller is configured to perform a sensor check prior to determining the second pose solution.

15. The positioning system of claim 14, wherein the sensor check includes a cross-check between the first and second sensors.

16. The positioning system of claim 15, wherein the sensor check further includes at least one of a communication check, a diagnostic check, a timing check, an out- of-range check, and an in-range check.

17. A method of determining a position of a mobile machine, comprising:

receiving, by a controller, a first pose solution from a memory location;

generating, by the controller, a measured pose of the mobile machine based on a first signal from a first sensor;

generating, by the controller, an estimated pose of the mobile machine based on the first pose solution and a second signal from a second sensor;

determining, by the controller, uncertainty values associated with each of the measured and estimated poses;

determining, by the controller, an overlap of the uncertainty values;

selectively adjusting, by the controller, the measured pose and uncertainty value based on the overlap; and

determining, by the controller, a second pose solution based on the estimated pose and adjustment of the measured pose.

18. The method of claim 17, wherein:

determining the second pose solution includes determining the second pose solution based on the estimated pose and adjustment of the measured pose only when the estimated and measured poses are generally synchronous; and

the method further includes selectively determining the second pose solution based on only the estimated pose when the estimated and measured poses are not generally synchronous and the uncertainty values do not overlap.

19. The method of claim 17, wherein adjusting the measured pose and uncertainty value includes adjusting the measured pose only when the uncertainty values overlap and the overlap is less than a threshold %.

20. The method of claim 17, further including performing a plurality of sensor checks prior to determining the second pose solution, the plurality of sensor checks including at least two of a cross-check, a communication check, a diagnostic check, a timing check, an out-of-range check, and an in-range check, wherein generating the measured and estimated poses includes generating the measured and estimated poses based on sensor input prior to performing the plurality of sensor checks.