TELEMATIC INTERFACE WITH CONTROL SIGNAL SCALING BASED ON FORCE SENSOR FEEDBACK

• US 20120185099A1
• Filed: 01/19/2011
• Published: 07/19/2012
• Est. Priority Date: 01/19/2011
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Bosscher, Paul M., Summer, Matthew D.
• Granted Patent: US 8,918,215 B2
• Time in Patent Office: Days
• US Class Current: 700/264
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: G05B 19/427 Teaching successive positions by tracking the position of a joystick or handle to control the positioning servo of the tool head, master-slave control G05B19/423 takes precedence

Abstract

Method and system for telematic control of a slave device. A stiffness of a material physically contacted by a slave device (202) is estimated based on information obtained from one or more slave device sensors (216, 217). Based on this stiffness estimation, a motion control command directed to the slave device is dynamically scaled. A data processing system (204) is in communication with a control interface (203) and the slave device. The data processing system (204) is configured to generate the motion control commands in response to sensor data obtained from the control interface. The system (200) also includes a stiffness estimator (602) configured for automatically estimating a stiffness of a material physically contacted by the slave device based on information obtained from the slave device sensors. A scaling unit (607) is responsive to the stiffness estimator and is configured for dynamically scaling the motion control command.

Claims

1. A method for telematic control of a slave device, comprising:

sensing a physical displacement of a user interface control in a control direction;

responsive to said sensing, communicating a motion control command to said slave device to cause a slave device motion;

based on information obtained from at least one slave device sensor, automatically estimating a stiffness of a material physically contacted by said slave device; and

dynamically scaling said motion control command based on said stiffness.

2. The method according to claim 1, further comprising specifying with said motion control command a first velocity at which said slave device is to move, and wherein said scaling step further comprises modifying said motion control command to specify a second velocity which is different compared to said first velocity.

3. The method according to claim 2, wherein said scaling step further comprises modifying said second velocity to be less than said first velocity.

4. The method according to claim 3, wherein said scaling step further comprises modifying said motion control command so that said second velocity is selectively decreased to a greater extent when said slave device physically contacts said material having a greater estimated stiffness as compared to said material having a lesser estimated stiffness.

5. The method according to claim 1, wherein said motion control command indicates a first distance which said slave device is to move, and said scaling step further comprises modifying said motion control command to specify a second distance which is different compared to said first distance.

6. The method according to claim 5, wherein said scaling step further comprises modifying said second distance to be less than said first distance.

7. The method according to claim 6, wherein said scaling step further comprises modifying said motion control command so that said second distance is selectively decreased to a greater extent when said slave device physically contacts said material having a greater estimated stiffness as compared to materials having a lesser estimated stiffness.

8. The method according to claim 1, further comprising estimating said stiffness based on a force measurement performed by at least a first one of said slave device sensors.

9. The method according to claim 8, further comprising estimating said stiffness based on a position measurement performed by at least a second one of said slave device sensors.

10. The method according to claim 9, further comprising estimating said stiffness based on a change in said force measurement and a change in said position measurement.

11. The method according to claim 1, further comprising performing said scaling step based on said stiffness which has been estimated and a magnitude of force exerted upon said slave device.

12. The method according to claim 8, further comprising using said information obtained from said first and second ones of said slave device sensors to provide haptic feedback at said user interface control.

13. A robot system, comprising:

a control interface having at least one control sensor for sensing a physical displacement of a user interface control in a control direction;

a slave device configured for moving in response to at least one motion control command, said slave device including at least one slave device sensor;

a data processing system in communication with said control interface and said slave device, and configured to generate said at least one motion control command in response to sensor data obtained from said at least one control sensor;

a stiffness estimator configured for automatically estimating a stiffness of a material physically contacted by said slave device based on information obtained from said at least one slave device sensor;

a scaling unit responsive to said stiffness estimator and configured for dynamically scaling said at least one motion control command based on said stiffness.

14. The robot system according to claim 13, wherein said motion control command indicates a first velocity at which slave device is to move, and wherein said scaling unit is configured to modify said motion control command to specify a second velocity which is different compared to said first velocity.

15. The robot system according to claim 14, wherein said scaling unit is configured to modify said second velocity to be less than said first velocity.

16. The robot system according to claim 15, wherein said scaling unit is configured to modify said motion control command so that said second velocity is selectively decreased to a greater extent when said slave device physically contacts said material having a greater estimated stiffness as compared to said material having a lesser estimated stiffness.

17. The robot system according to claim 13, wherein said motion control command indicates a first distance which slave device is to move, and said scaling unit is configured to modify said motion control command to specify a second distance which is different compared to said first distance.

18. The robot system according to claim 17, wherein said scaling unit is configured to modify said second distance to be less than said first distance.

19. The robot system according to claim 18, wherein said scaling unit is configured to modify said motion control command so that said second distance is selectively decreased to a greater extent when said slave device physically contacts said material having a greater estimated stiffness as compared to said material having a lesser estimated stiffness.

20. The robot system according to claim 13, wherein said stiffness estimator is configured to estimate said stiffness based on a force measurement performed by at least a first one of said slave device sensors.

21. The robot system according to claim 20, wherein said stiffness estimator is configured to estimate said stiffness based on a position measurement performed by at least a second one of said slave device sensors.

22. The robot system according to claim 21, wherein said stiffness estimator is configured to estimate said stiffness based on a change in said force measurement and a change in said position measurement.

23. The robot system according to claim 13, wherein said data processing system is responsive to said information obtained from said at least one slave device sensor for generating a haptic feedback control signal, and said user interface control further comprises at least one motivating device responsive to said haptic feedback control signal for generating haptic feedback.