System and a method for enabling a vehicle to track a preset path

• US 5,838,562 A
• Filed: 05/01/1995
• Issued: 11/17/1998
• Est. Priority Date: 02/05/1990
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Shaffer, Gary K., Rao, Prithvi N., Sennott, James W., Shi, Wenfan, West, Jay H., Wu, Baoxin, Gudat, Adam J., Koehrsen, Craig L., Whittaker, William L., Shin, Dong Hun, 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.
• Primary Examiner(s): PARK, COLLIN
• Application Number:
  US08/432,248
• Time in Patent Office: 1,296 Days
• Field of Search: 364/424.02, 364/443, 364/447, 364/449, 364/453, 180/167, 180/168, 180/169, 318/580, 318/587
• US Class Current: 701/213
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60K 31/04 and means for comparing one electrical quantity, e.g. voltage, pulse, waveform, flux, or the like, with another quantity of a like kind, which comparison means is involved in the development of an electrical signal which is fed into the controlling means
• CPC Class Codes: B62D 1/28 non-mechanical , e.g. following a line or other known markers
• 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 1/0011 associated with a remote control arrangement
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0242 using non-visible light signals, e.g. IR or UV signals
• CPC Class Codes: G05D 1/0268 using internal positioning means
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/0278 : using satellite positioning signals, e.g. GPS
• CPC Class Codes: G05D 1/0297 : by controlling means in a control room
• 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 system for a vehicle for enabling said vehicle to track a preset path comprising:

supervisory means for representing a desired path as at least a fourth order continuous function;

means for planning steering, by outputting a desired steering angle, based on said desired path from said supervisory means and sensed vehicle positions input from a positioning system;

means for controlling steering of the vehicle, by outputting steering servo commands to a steering system of the vehicle, responsive to said desired steering angle from said means for planning steering and to feedback from said steering system of the vehicle;

means for setting speed, by outputting a desired speed signal, based on a desired speed input from said supervisory means; and

means for controlling the speed of the vehicle, by outputting speed commands to a vehicle speed system, wherein said speed command is based on a difference between said desired speed signal and an actual vehicle speed fed back from said vehicle speed system.

2. A system according to claim 1, wherein said at least fourth order continuous function is evaluated from a cubic B-spline function.

3. A system according to claim 1, wherein said desired path is a geometric curve independent of time.

4. A system according to claim 1, wherein said desired speed is independent of said desired path.

5. A system according to claim 1, wherein said means for controlling steering of the vehicle is decoupled from said means for controlling the speed of the vehicle.

6. A method of operating a system for a vehicle for enabling said vehicle to track a preset path comprising the steps of:

(1) representing a desired path as at least a fourth order continuous function;

(2) planning steering, by outputting a desired steering angle, based on said desired path and sensed vehicle positions;

(3) controlling steering of said vehicle, by outputting steering servo commands to a steering system of the vehicle, responsive to said desired steering angle and to feedback from said steering system of the vehicle;

(4) setting speed, by outputting a desired speed signal, based on a desired speed; and

(5) controlling the speed of the vehicle, by outputting speed commands to a vehicle speed system, wherein said speed command is based on a difference between said desired speed signal and an actual vehicle speed fed back from said vehicle speed system.

7. A method according to claim 6, wherein step (1) comprises:

representing the desired path as the at least fourth order function evaluated from a cubic B-spline function.

8. A method according to claim 6, wherein step (1) comprises:

representing the desired path as the at least fourth order function that is a geometric curve independent of time.

9. A method according to claim 6, wherein said desired speed is independent of said desired path.

10. A method according to claim 6, wherein step (3) is decoupled to step (5).