Integrated vehicle positioning and navigation system, apparatus and method

• US 5,610,815 A
• Filed: 02/05/1990
• Issued: 03/11/1997
• Est. Priority Date: 12/11/1989
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Shin, Dong H., Gudat, Adam J., Shaffer, Gary K., Koehrsen, Craig L., Whittaker, William L., Kemner, Carl A., Devier, Lonnie J., Kyrtsos, Christos T., Lay, Norman K., Peterson, Joel L., Schmidt, Larry E., Kleimenhagen, Karl W., Stafford, Darrell E., Weinbeck, Louis J., Singh, Sanjiv J., Christensen, Dana A., Clow, Richard G., Bradbury, Walter J., Rao, Prithvi N., Sennott, James W., Shi, Wenfan, West, Jay H., Wu, Baoxin
• Primary Examiner(s): Park, Collin W.
• Application Number:
  US07/487,980
• Time in Patent Office: 2,591 Days
• Field of Search: 364/424.02, 364/443, 364/449-450, 364/453, 364/454, 364/460, 364/461, 180/169, 395/904, 342/357, 342/450, 342/455, 342/457, 73/178 R, 318/587, 340/988, 340/436
• US Class Current: 701/23
• 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 system (400) for positioning and navigating an autonomous vehicle (310) allows the vehicle (310) to travel between locations. Position information (432) is derived from global positioning system satellites (200, 202, 204, and 206) or other sources (624) when the satellites (200, 202, 204, and 206) are not in the view of the vehicle (310). Navigation of the vehicle (310) is obtained using the position information (432), route information (414), obstacle detection and avoidance data (416), and on board vehicle data (908 and 910).

Claims

1. A computer-based system for autonomously navigating a vehicle along a predetermined path, the system comprising:

(1) positioning means for determining a location of the vehicle, said positioning means including

(a) a first positioning system to provide a first position estimate of the vehicle based on signals from a satellite-based positioning system,

(b) a motion positioning system to provide a second position estimate of the vehicle, and

(c) a processing system adapted to compute a third position estimate of the vehicle from said first position estimate and said second position estimate;

(2) navigation means for causing the vehicle to track the predetermined path, said navigation means including

(a) first means for retrieving from a table a given posture comprising reference path curvature, maximum velocity, desired heading, and desired vehicle position coordinates of the predetermined path,

(b) second means for determining a reference steering angle from the reference path curvature,

(c) third means for determining a posture error based on said retrieved posture and said third position estimate,

(d) fourth means for determining a desired steering angle from said reference steering angle and said posture error,

(e) fifth means for using said desired steering angle to direct the vehicle toward the predetermined path,

(f) sixth means for determining a commanded speed less than said maximum velocity, and

(g) seventh means for using said commanded speed to control the speed of the vehicle; and

(3) detection means for causing the vehicle to detect and avoid obstacles while tracking the predetermined path.

2. A computer-based method for autonomously navigating a vehicle along a predetermined path, the method comprising the steps of:

(1) determining a location of the vehicle, said step of determining including the steps of

(a) determining a first position estimate of the vehicle based on signals from a satellite-based positioning system,

(b) receiving a second position estimate of the vehicle from a motion positioning system, and

(c) computing a third position estimate of the vehicle from said first position estimate and said second position estimate;

(2) causing the vehicle to track the predetermined path, said step of causing including the steps of

(a) retrieving from a table a given posture comprising reference path curvature, maximum velocity, desired heading, and desired vehicle position coordinates of the predetermined path,

(b) determining a reference steering angle from the reference path curvature,

(c) determining a posture error based on said retrieved posture and said third position estimate,

(d) determining a desired steering angle from said reference steering angle and said posture error,

(e) using said desired steering angle to direct the vehicle toward the predetermined path,

(f) determining a commanded speed less than said maximum velocity, and

(g) using said commanded speed to control the speed of the vehicle; and

(3) causing the vehicle to detect and avoid obstacles while tracking the predetermined path.

3. A computer-based system for autonomously navigating a vehicle along a predetermined path, the system comprising:

(1) positioning means for determining a location of the vehicle, said positioning means including

(a) a first positioning system to provide a first position estimate of the vehicle based on first signals from a satellite-based positioning system,

(b) a motion positioning system to provide a second position estimate of the vehicle based on second signals from an inertial reference unit mounted on the vehicle and a vehicle odometer, and

(c) a processing system adapted to compute a third position estimate of the vehicle from said first position estimate and said second position estimate;

(2) navigation means for causing the vehicle to track the predetermined path, said navigation means including

(a) first means for retrieving from a table a given posture comprising reference path curvature, maximum velocity, desired heading, and desired vehicle position coordinates of the predetermined path,

(b) second means for determining a reference steering angle from the reference path curvature,

(c) third means for determining a posture error based on said retrieved posture and said third position estimate,

(d) fourth means for determining a desired steering angle from said reference steering angle and said posture error,

(e) fifth means for using said desired steering angle to direct the vehicle toward the predetermined path,

(f) sixth means for determining a commanded speed less than said maximum velocity, and

(g) seventh means for using said commanded speed to control the speed of the vehicle; and

(3) detection means for causing the vehicle to detect and avoid obstacles while tracking the predetermined path.

4. The computer-based system of claim 3, wherein said first positioning system comprises a GPS receiver.

5. The computer-based system of claim 4, wherein said motion positioning system comprises an inertial reference unit and a vehicle odometer.

6. The computer-based system of claim 3, wherein said navigation means further comprises:

eighth means for controlling lateral acceleration during turning.

7. The computer-based system of claim 3, wherein said navigation means further comprises:

eighth means for determining a vehicle stopping distance from an actual vehicle speed and a specified maximum vehicle deceleration value; and

ninth means for modifying said commanded speed in accordance with a distance to an object received from said detection means to allow the vehicle to stop before contacting said object.

8. The computer-based system of claim 3, wherein said sixth means comprises:

means for monitoring speed setpoints set by one of a host computer and said detection means; and

means for setting said commanded speed equal to a smallest one of said speed setpoints.

9. A computer-based method for autonomously navigating a vehicle along a predetermined path, the method comprising the steps of:

(1) determining a location of the vehicle, said step of determining including the steps of

(a) determining a first position estimate of the vehicle based on signals from a satellite-based positioning system,

(b) receiving a second position estimate of the vehicle from a motion positioning system based on second signals from an inertial reference unit mounted on the vehicle and a vehicle odometer, and

(c) computing a third position estimate of the vehicle from said first position estimate and said second position estimate;

(2) causing the vehicle to track the predetermined path, said step of causing including the steps of

(a) retrieving from a table a given posture comprising reference path curvature, maximum velocity, desired heading, and desired vehicle position coordinates of the predetermined path,

(b) determining a reference steering angle from the reference path curvature,

(c) determining a posture error based on said retrieved posture and said third position estimate,

(d) determining a desired steering angle from said reference steering angle and said posture error,

(e) using said desired steering angle to direct the vehicle toward the predetermined path,

(f) determining a commanded speed less than said maximum velocity, and

(g) using said commanded speed to control the speed of the vehicle; and

(3) causing the vehicle to detect and avoid obstacles while tracking the predetermined path.

10. The computer-based method of claim 9, wherein said step (2) of causing further comprises:

(h) controlling lateral acceleration during turning.

11. The computer-based method of claim 9, wherein said step (2) of causing further comprises:

(h) determining a vehicle stopping distance from an actual vehicle speed and a specified maximum vehicle deceleration value; and

(I) modifying said commanded speed in accordance with a distance to an object received from a detection means to allow the vehicle to stop before contacting said object.

12. The computer-based method of claim 9, wherein said step (f) of determining a commanded speed comprises:

monitoring speed setpoints set by one of a host computer and a detection means; and

setting said commanded speed equal to a smallest one of said speed setpoints.