Force display master interface device for teleoperation

• US 6,435,794 B1
• Filed: 06/29/2001
• Issued: 08/20/2002
• Est. Priority Date: 11/18/1998
• Status: Expired due to Fees

• Current Assignee: Wisconsin Alumni Research Foundation (University of Wisconsin System)
• Original Assignee: Scott L. Springer
• Inventors: Springer, Scott L.
• Primary Examiner(s): Olszewski, Robert P.
• Assistant Examiner(s): O'Connor, Gerald J.
• Application Number:
  US09/896,674
• Time in Patent Office: 417 Days
• Field of Search: 414/5, 414/730, 414/800, 340/407.1, 703/5, 703/7, 600/595
• US Class Current: 414/5
• CPC Class Codes: B25J 13/02 Hand grip control means handles or pedals for crane control B66C13/56; for measuring the force applied to control members G01L5/22; hand-held casings for switching devices, e.g. joy-sticks H01H9/0214
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02
• CPC Class Codes: G06F 3/016 Input arrangements with force or tactile feedback as computer generated output to the user

Abstract

A force display master interface is provided for interaction with teleoperated robotic slave manipulators or virtual slave entities. The device provides a de-coupled actuator that permits selective engagement between the actuator and the fingertip. A method for high speed control of force display masters is disclosed, which includes determination of a pre-contact state of the slave entity and an object in the slave environment. Operation on the pre-contact state information is used to pre-position the actuator into an appropriate position to represent the contact to the operator, before slave contact is made. In one embodiment, the force display master provides a hand mounted linkage assembly, in combination with a remote control assembly that measures fingertip motion and selectively provides resistance thereto. In another embodiment the invention includes general linkage-actuator arrangements that can be used singly or in combination to provide a variety of master interface devices.

Claims

1. A force display master interface device for teleoperation wherein the master interface device is used by an operator for simulating interaction between a slave entity and an object in the slave environment, the master interface device comprising:

linkage means for connection to the operator and for selectively providing resistance to operator motion,

force generation means operatively connected to said linkage means for generation of a force and application of the force to said linkage means;

whereby the operative connection between said linkage means and said force generation means includes;

a state of physical contact whereby the force generation means provides the force to the linkage means resulting in resistance to operator motion, said state of physical contact occurring in response to the slave entity contact with the object,

a maximum offset distance between said linkage means and said force generation means in response to the slave entity separation from the object by more than a predetermined distal separation distance,

and at least one intermediate offset distance between said linkage means and said force generation means in response to the slave entity separation from the object by less than at least one predetermined proximal separation distance.

2. The device set forth in claim 1 comprising a multitude of predetermined intermediate offset distances and a multitude of corresponding predetermined proximal separation distances, whereby each intermediate offset distance is proportional to the corresponding proximal separation distance.

3. The device set forth in claim 1 whereby the operative connection includes a plurality of offset distances between said linkage means and said force generation means, whereby each offset distance is proportional to one of a plurality of separation distances between the slave entity and the object.

4. A force display master interface device for teleoperation wherein the master interface device is used by an operator for simulating interaction between a slave entity and an object in the slave environment, the master interface device comprising:

resistive means for an operative connection to an operator and for providing resistance to operator motion,

whereby the operative connection between said operator and said resistive means includes;

a resistance condition where the resistive means provides resistance to operator motion in response to the slave entity contact with the object,

a maximum displacement condition whereby resistive means does not provide resistance to operator motion and operator displacement by a first distance results in said resistance condition, and said maximum displacement condition is realized in response to the slave entity separation from the object by more than a first predetermined separation distance,

and at least one intermediate displacement condition whereby resistive means does not provide resistance to operator motion and operator displacement by a second distance results in said resistance condition, and said intermediate displacement condition is realized in response to the slave entity separation from the object by less than at least one second predetermined separation distance.

5. The device set forth in claim 4 wherein resistive means further comprises a linkage means and an actuation means, whereby the operative connection between the operator and the resistive means occurs between the actuation means and the linkage means.

6. The device set forth in claim 5 wherein the linkage means comprises a plurality of interconnected links and the actuation means comprises a plurality if actuators, whereby each actuator forms an operative connection with a link.

7. The device set forth in claim 6 wherein each link represents one degree of freedom in the motion represented by the device.

8. The device set forth in claim 6 wherein each actuator represents one degree of freedom in the motion represented by the device.

9. The device set forth in claim 4 including a multitude of intermediate displacement conditions;

whereby the resistive means does not provide resistance to operator motion,

and operator displacement by a multitude of predetermined second distances results in said resistance condition,

and said intermediate displacement conditions are proportional to the second predetermined separation distances.

10. A force display master interface device for teleoperation wherein the master interface device is used by an operator for simulating interaction between a slave entity and an object in the slave environment, the master interface device comprising:

linkage means for connection to the operator and for providing a sensation signal to the operator,

signal generation means for generation of the sensation signal and selective transfer of the sensation signal to the linkage means,

whereby the selective transfer includes;

a contact state between the signal generation means and the linkage means applied in response to slave entity contact with the object,

a pre-contact state between the signal generation means and the linkage means in response to a separation distance between the slave entity and the object,

whereby the pre-contact state includes;

controlling the magnitude of the signal delivered by the signal generation means to be one of a plurality of predetermined values.

11. The device set forth in claim 10 wherein the signal generation means is an actuator for producing a position signal in response to an electric signal, the position signal is the sensation signal.

12. The device set forth in claim 11 wherein the pre-contact state includes fixing the position of the actuator relative to its ground location in response to a predetermined proximal separation distance between the slave entity and the object.

13. The device set forth in claim 10 wherein the signal generation means includes means for producing a force, and the force is the sensation signal.

14. The device set forth in claim 10 wherein the signal generation means includes at least two contact surfaces including a first contact surface and a second contact surface,

and the pre-contact state includes; selective control of the distance between the first contact surface and the linkage means in response to operator motion in a first direction,

and selective control of the distance between the second contact surface and the linkage means in response to operator motion in a second direction.

15. A device for force display to human operators, to simulate forces experienced by a slave entity while interacting with a slave object, including;

operator position measurement means,

slave control means for controlling the slave entity position to follow displacements proportional to the operator displacements,

slave contact means for activation when the slave entity and the slave object are in contact and deactivation otherwise,

slave proximity means for activation when the slave object is within a predetermined distance from the slave entity and deactivation otherwise,

linkage means for transmitting a force to the operator,

actuator means for generation of the force,

actuator control means for controlling the actuator to assume a position offset from the linkage means by an offset distance,

whereby the offset distance is controlled to assume one of a plurality of predetermined offset distances, in response to the slave proximity means.

16. The device set forth in claim 15 whereby the offset distance includes;

a zero distance in response to the slave contact means activation,

a predetermined maximum distance in response to slave proximity means deactivation,

at least one intermediate distance in response to slave proximity means activation.

17. The device set forth in claim 15 whereby the slave proximity means includes means for determination of a separation distance between the slave entity and the slave object while in the activation state,

whereby the offset distance is proportional to the separation distance.