Coordinated joint motion control system

• US 8,145,355 B2
• Filed: 11/24/2008
• Issued: 03/27/2012
• Est. Priority Date: 08/31/2001
• Status: Active Grant

• Current Assignee: Board of Regents Nevada System of Higher Education (State of Nevada)
• Original Assignee: Board of Regents Nevada System of Higher Education (State of Nevada)
• Inventors: Danko, George
• Primary Examiner(s): Tran, Khoi
• Assistant Examiner(s): Moyer, Dale
• Application Number:
  US12/276,791
• Publication Number:
  US 20090099738A1
• Time in Patent Office: 1,219 Days
• Field of Search: 707/50, 700245-264
• US Class Current: 700/251
• CPC Class Codes: B25J 9/1607 Calculation of inertia, jacobian matrixes and inverses
• CPC Class Codes: B25J 9/1651 acceleration, rate control
• CPC Class Codes: E02F 3/437 providing automatic sequences of movements, e.g. linear excavation, keeping dipper angle constant
• CPC Class Codes: E02F 3/438 Memorising movements for repetition, e.g. play-back capability
• CPC Class Codes: E02F 3/439 Automatic repositioning of the implement, e.g. automatic dumping, auto-return E02F3/438 takes precedence
• CPC Class Codes: E02F 9/2037 Coordinating the movements of the implement and of the frame
• CPC Class Codes: E02F 9/2041 Automatic repositioning of implements, i.e. memorising determined positions of the implement for dipper-arms or bucket-arms E02F3/434, E02F3/437, E02F3/438, E02F3/439 take precedence
• CPC Class Codes: G05B 2219/39062 Calculate, jacobian matrix estimator
• CPC Class Codes: G05B 2219/39224 Jacobian transpose control of force vector in configuration and cartesian space
• CPC Class Codes: G05B 2219/40495 Inverse kinematics model controls trajectory planning and servo system

Abstract

A coordinated joint control system for controlling a coordinated joint motion system, e.g. an articulated arm of a hydraulic excavator blends automation of routine tasks with real-time human supervisory trajectory correction and selection. One embodiment employs a differential control architecture utilizing an inverse Jacobian. Modelling of the desired trajectory of the end effector in system space can be avoided. The disclosure includes image generation and matching systems.

Claims

1. A tangible computer-readable storage medium storing computer-executable instructions for causing a computer system programmed thereby to perform a method comprising:

controlling a user-manipulable implement in real time, including;

outputting to a display device a menu of virtual kinematics configurations, each virtual kinematics configuration comprising a plurality of trajectory paths of the user-manipulable implement, each trajectory path comprising at least two dimensions;

selecting one of the plurality of trajectory paths;

calculating velocity components for the selected trajectory path in a first coordinate space;

in a differential control kinematics generator, modifying the velocity components based on first feedback signals received from an input device to provide modified velocity components in the first coordinate space, the first feedback signals being received as part of a first feedback loop;

generating a position-dependent inverse kinematics model for converting between the first coordinate space and a second coordinate space, wherein the generation of the position-dependent inverse kinematics model uses second feedback signals received as part of a second feedback loop; and

based on the position-dependent inverse kinematics model and the modified velocity components, outputting velocity components in the second coordinate space to at least one of a plurality of control connections associated with a plurality of joints of the user-manipulable implement.

2. The computer-readable storage medium of claim 1, the method further comprising receiving input signals from an input device regarding a virtual kinematics configuration selected by a user, wherein the selection of one of the plurality of trajectory paths is based at least in part on the received input signals.

3. The computer-readable storage medium of claim 1, the method further comprising receiving input signals from an input device, the received input signals indicating the first feedback signals.

4. A system comprising:

a processor;

the tangible computer readable storage medium of claim 1.

5. The system of claim 4, further comprising a display.

6. The system of claim 4, further comprising an input device, the input device configured to generate signals allowing an operator to select a virtual kinematics configuration from the displayed menu.

7. The system of claim 4, further comprising an input device, the input device configured to generate signals indicating the first feedback signals.

8. The computer-readable storage medium of claim 1 wherein the first feedback signals are desired trajectory path changes or desired control changes, wherein the first feedback signals indicate adjustments to the velocity components in the first coordinate space, and wherein the second feedback signals are control measurements in the second coordinate space.

9. The computer-readable storage medium of claim 1 wherein the first coordinate space is Cartesian coordinate space, and wherein the second coordinate space is polar coordinate space.

10. The computer-readable storage medium of claim 1 wherein the first feedback loop is a user-driven feedback loop that allows a user to adjust the velocity components for the selected trajectory path in the first coordinate space, and wherein the second feedback loop is a control-driven feedback loop according to which the position-dependent inverse kinematics model is adjusted.

11. The computer-readable storage medium of claim 1 wherein the controlling the user-manipulable implement in real time further comprises:

repeating the modification of the velocity components based on first feedback signals, the generation of the position-dependent inverse kinematics model using second feedback signals, and the outputting the velocity components in the second coordinate space.

12. A method comprising:

storing on a computer-readable storage medium computer-executable instructions for causing a computer system programmed thereby to perform acts comprising controlling a user-manipulable implement in real time, including;

outputting to a display device a menu of virtual kinematics configurations, each virtual kinematics configuration comprising a plurality of trajectory paths of the user-manipulable implement, each trajectory path comprising at least two dimensions;

calculating velocity components for the selected trajectory path in a first coordinate space;

in a differential control kinematics generator, modifying the velocity components based on first feedback signals received from an input device to provide modified velocity components in the first coordinate space, the first feedback signals being received as part of a first feedback loop;

generating a position-dependent inverse kinematics model for converting between the first coordinate space and a second coordinate space, wherein the generation of the position-dependent inverse kinematics model uses second feedback signals received as part of a second feedback loop; and

based on the position-dependent inverse kinematics model and the modified velocity components, outputting velocity components in the second coordinate space to at least one of a plurality of control connections associated with a plurality of joints of the user-manipulable implement.

13. A computer-implemented method of operating an apparatus comprising a user-manipulable implement comprising a plurality of joints, the method comprising:

controlling the user-manipulable implement in real time, including;

outputting to a display device a menu of virtual kinematics configurations, each virtual kinematics configuration comprising a plurality of trajectory paths of the user-manipulable implement, each trajectory path comprising at least two dimensions;

selecting one of the plurality of trajectory paths;

calculating velocity components for the selected trajectory path in a first coordinate space;

in a differential control kinematics generator, modifying the velocity components based on first feedback signals received from an input device to provide modified velocity components in the first coordinate space, the first feedback signals being received as part of a first feedback loop;

generating a position-dependent inverse kinematics model for converting between the first coordinate space and a second coordinate space, wherein the generation of the position-dependent inverse kinematics model uses second feedback signals received as part of a second feedback loop; and

based on the position-dependent inverse kinematics model and the modified velocity components, outputting velocity components in the second coordinate space to at least one of a plurality of control connections associated with the plurality of joints of the user-manipulable implement.

14. The method of claim 13 wherein the first feedback signals are desired trajectory path changes or desired control changes, wherein the first feedback signals indicate adjustments to the velocity components in the first coordinate space, and wherein the second feedback signals are control measurements in the second coordinate space.

15. The method of claim 13 wherein the first coordinate space is Cartesian coordinate space, and wherein the second coordinate space is polar coordinate space.

16. The method of claim 13 wherein the first feedback loop is a user-driven feedback loop that allows a user to adjust the velocity components for the selected trajectory path in the first coordinate space, and wherein the second feedback loop is a control-driven feedback loop according to which the position-dependent inverse kinematics model is adjusted.

17. The method of claim 13 wherein the controlling the user-manipulable implement in real time further comprises:

repeating the modification of the velocity components based on first feedback signals, the generation of the position-dependent inverse kinematics model using second feedback signals, and the outputting the joint control components.