Method and apparatus for machine element control

• US 20060201007A1
• Filed: 03/14/2005
• Published: 09/14/2006
• Est. Priority Date: 03/14/2005
• Status: Active Grant

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Piekutowski, Richard Paul
• Granted Patent: US 7,168,174 B2
• Time in Patent Office: Days
• US Class Current: 33/286
• CPC Class Codes: E01C 19/006 by laser or ultrasound
• CPC Class Codes: E02F 3/847 using electromagnetic, optical or acoustic beams to determine the blade position, e.g. laser beams

Abstract

A method of monitoring the location, and the orientation of a machine element, and apparatus for monitoring and controlling the operation of the machine include a robotic total station and a plurality of targets in known positions relative to the machine element. The total station, located at a known location near the machine element, repeatedly, successively determines the location of each target. Acquisition and re-acquisition of the targets is aided by stored data regarding the prior locations and movements of the targets. Further, active targets may be used to facilitate re-acquisition. The operation of the machine is controlled based upon the location and orientation of the machine element.

Claims

1. A method of monitoring the location, and the orientation of a machine element, comprising:

providing a plurality of targets in known positions relative to the machine element,

providing a total station at a known location near said machine element,

repeatedly, successively determining the location of each target using said total station, and

determining the orientation of said machine element based on the locations of said plurality of targets.

2. The method of claim 1, in which the step of repeatedly, successively determining the location of each target using said total station comprises the step of directing a beam of laser light from said total station repeatedly in succession to each of said plurality of targets, and measuring the distances from said total station to each of said plurality of targets and the directions to each of said plurality of targets.

3. The method of claim 2, in which the step of repeatedly, successively determining the location of each target using said total station comprises directing a beam of laser light from said total station to said targets by acquiring said targets in succession.

4. The method of claim 3, in which the step of acquiring said targets in succession comprises the step of storing the detected locations of each of said targets and the movement history of each of said targets, and predicting the locations of each of said targets as said laser beam is directed repeatedly in succession to each of said targets, whereby the reacquisition of said targets is facilitated.

5. The method of claim 1, in which the step of providing a plurality of targets in known positions with respect to the machine element comprises the step of providing a pair of targets that are fixed in known positions on said machine element and moveable with said machine element.

6. The method of claim 5, in which the step of providing a pair of targets that are fixed in known positions on said machine element and moveable with said machine element comprises the step of providing a pair of targets that are fixed in symmetrical positions with respect to said machine element.

7. A method of controlling the movement of a machine element, comprising:

providing a plurality of targets in known positions with respect to a moving machine element,

providing a total station at a known location near said moving machine element,

repeatedly, successively determining the location of each target using said total station,

transmitting the location of each target determined by the total station from the total station to the machine,

at the machine, determining the orientation of said machine element based on the locations of said targets, and

at the machine controlling the movement of the machine element in response to the determined locations of said targets and the determined orientation of said machine element.

8. The method of claim 7, in which the step of repeatedly, successively determining the location of each target using said total station comprises the step of directing a beam of laser light from said total station repeatedly in succession to each of said plurality of targets, and measuring the distances from said total station to each of said plurality of targets and the directions to each of said plurality of targets.

9. The method of claim 8, in which the step of repeatedly, successively determining the location of each target using said total station comprises directing a beam of laser light from said total station to said targets by acquiring said targets in succession.

10. The method of claim 9, in which the step of acquiring said targets in succession comprises the step of storing the detected locations of each of said targets and the movement history of each of said targets, and predicting the locations of each of said targets as said laser beam is directed repeatedly in succession to each of said targets, whereby the reacquisition of said targets is facilitated.

11. The method of claim 7, in which the step of providing a plurality of targets in known positions with respect to said machine element comprises the step of providing a pair of targets that are fixed in known positions on said machine element and moveable with said machine element.

12. The method of claim 11, in which the step of providing a pair of targets that are fixed in known positions on said machine element and moveable with said machine element comprises the step of providing a pair of targets that are fixed in symmetrical positions with respect to said machine element.

13. A system for controlling the movement of a machine element on a machine, comprising:

a control on said machine for control of said machine element;

a plurality of targets mounted in known positions with respect to a moving machine element; and

a total station positioned at a known location near said moving machine element, said total station including

a laser light source for providing a beam of laser light on said targets,

a target prediction unit for predicting the locations of each of said targets based on previous locations and movement of the targets,

a beam control for directing the beam of laser light on said targets and repeatedly, successively determining the location of each target, and

a transmitter for transmitting the locations of each of the targets to the control on said machine;

whereby the measured locations of the targets can be used to determine the location, orientation, and movement of the machine element to facilitate control of the machine element.

14. The system of claim 13, in which the total station further includes a measurement unit for measuring the distances from said total station to each of said targets and the directions to each of said targets.

15. The system of claim 13, in which said plurality of targets comprises a pair of targets.