Laser Sensors For Trolley Guidance Signal

• US 20130261868A1
• Filed: 03/30/2012
• Published: 10/03/2013
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Ruth, Eric J., Stratton, Ken L.
• Granted Patent: US 8,838,320 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: B62D 6/00 Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00
• CPC Class Codes: G05D 1/00 Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots drive control systems specially adapted for autonomous road vehicles B60W60/00
• CPC Class Codes: G05D 1/024 in combination with a laser lasers per se H01S
• CPC Class Codes: G05D 1/0278 using satellite positioning signals, e.g. GPS

Abstract

A system and method for guiding an off-highway truck along a roadway with respect to a trolley line determine a position of the off-highway truck on the roadway by sensing two or more roadside objects and uses the determined position of the off-highway truck and a known position of the trolley line relative to the two or more roadside objects to automatically determine a relative position of the off-highway truck under the trolley line. Based on the relative position of the off-highway truck under the trolley line, the off-highway truck is automatically steered to alter the position of the off-highway truck relative to the trolley line, e.g., to maintain an electrical power flow from the trolley line to the off-highway truck.

Claims

1. A method for guiding an off-highway truck along a roadway with respect to a trolley line, the off-highway truck having a processor configured as a controller, the method comprising:

the controller determining a position of the off-highway truck on the roadway by sensing two or more roadside objects located beside the roadway;

the controller using the determined position of the off-highway truck on the roadway and a known position of the trolley line relative to the two or more roadside objects to automatically determine a relative position of the off-highway truck under the trolley line; and

based on the determined relative position of the off-highway truck under the trolley line, the controller automatically steering the off-highway truck to alter the position of the off-highway truck relative to the trolley line.

2. The method for guiding an off-highway truck along a roadway in accordance with claim 1 wherein the two or more roadside objects located beside the roadway are support poles for the trolley line.

3. The method for guiding an off-highway truck along a roadway in accordance with claim 2 wherein sensing the two or more roadside objects includes illuminating the two or more roadside objects with laser illumination.

4. The method for guiding an off-highway truck along a roadway in accordance with claim 3 wherein determining a position of the off-highway truck includes triangulating based on angular positions of the two or more roadside objects.

5. The method for guiding an off-highway truck along a roadway in accordance with claim 3 wherein each of the two or more roadside objects includes a reflector to reflect the laser illumination.

6. The method for guiding an off-highway truck along a roadway in accordance with claim 5 wherein the reflector is one of a retro-reflector and a reflective corner cube.

7. The method for guiding an off-highway truck along a roadway in accordance with claim 1, wherein the off-highway truck includes a pantograph for contacting the trolley line, the method further comprising automatically determining whether to raise or lower the pantograph based on the position of the off-highway truck and a predetermined feature of the trolley line.

8. The method for guiding an off-highway truck along a roadway in accordance with claim 7, wherein the predetermined feature of the trolley line is retrieved from a position-encoded map of the trolley line.

9. The method for guiding an off-highway truck along a roadway in accordance with claim 1, further including disabling automatic steering of the off-highway truck if an operator of the off-highway truck overrides an automatic steering action.

10. The method for guiding an off-highway truck along a roadway in accordance with claim 1, further including disabling automatic steering of the off-highway truck and activating a brake of the off-highway truck if an operator of the off-highway truck releases a dead man mechanism.

11. The method for guiding an off-highway truck along a roadway in accordance with claim 1, further including disabling automatic steering of the off-highway truck and activating a brake of the off-highway truck when an imminent collision is detected.

12. A system for automatic guidance of an off-highway truck at a work site, the work site including a trolley line for supplying electric power to the off-highway truck, the trolley line running along a roadway having two or more roadside features, the system comprising:

a pantograph for selectively contacting the trolley line;

one or more sensors associated with the off highway truck; and

a controller linked to the one or more sensors and to a machine steering control and configured to detect a position of the off-highway truck relative to the trolley line by detecting the two or more roadside features and to automatically steer the truck via the machine steering control to maintain the pantograph in contact with the trolley line.

13. The system for automatic guidance of an off-highway truck according to claim 12, wherein the controller is further linked to a pantograph control and is configured to automatically raise or lower the pantograph.

14. The system for automatic guidance of an off-highway truck according to claim 12, further comprising an operator interface including a selector to permit the user to activate or deactivate automatic machine guidance.

15. The system for automatic guidance of an off-highway truck according to claim 12, further comprising a data source linked to the controller and containing data identifying a lateral location of the trolley line relative to the two or more roadside features.

16. The system for automatic guidance of an off-highway truck according to claim 15, wherein the data source further contains data encoding start and stop locations of the trolley line, and wherein the controller is further configured to raise or lower the pantograph based on the start and stop locations of the trolley line.

17. The system for automatic guidance of an off-highway truck according to claim 15, further including a GPS receiver linked to the controller and providing data indicative of a current position of the off-highway truck.

18. The system for automatic guidance of an off-highway truck according to claim 12, wherein the one or more sensors associated with the off highway truck comprise one or more laser sensors.

19. The system for automatic guidance of an off-highway truck according to claim 12, wherein the two or more roadside features comprise a consecutive plurality of poles positioned at a fixed distance from one another in the direction of the roadway and positioned at a fixed distance from the trolley line in a direction perpendicular to the roadway.

20. A system for automatic guidance of an off-highway truck having an onboard laser sensor, the system including:

a trolley line for supplying electric power to the off-highway truck, the trolley line running along a roadway;

a plurality of poles positioned consecutively in the direction of the roadway and positioned at a fixed distance from the trolley line in a direction perpendicular to the roadway; and

a reflective element fixed to each of the plurality of poles at a fixed distance above the roadway such that the laser sensor of the off-highway truck is able to detect two or more of the plurality of poles based on reflections from the reflective elements associated with the two or more of the plurality of poles.