Dynamic physical constraint for hard surface emulation
AssigneePerception Raisonnement Action en Medecine
InventorsAntony Hodgson, Christopher Plaskos, Nikolai Hungr
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Abstract
A method and apparatus for haptic hard surface emulation using a dynamic physical constraint are provided. The movement and position of the dynamic physical constraint is actively controlled in order to emulate a hard surface. The dynamic physical constraint may be controlled by a computer. In another aspect of the invention, the dynamic physical constraint limits the motion of a manipulator joint in space. The position at any time of the dynamic physical constraint is dependent on the position in space of the manipulator's end effector.
Claims12
An apparatus for guiding a user comprising:
- a robot having an end-effector which is adapted to be manipulated by an application of external forces, wherein the robot has at least one actuated joint and zero or more passive joints;
- wherein the at least one actuated joint is configured to position a physical constraint that limits the motion of at least one other joint in at least one direction.
A method for controlling movements of an end-effector comprising the steps of:
- applying a force on the end-effector of a manipulator causing motion at joints of the manipulator;
- determining a current position of the end-effector;
- comparing the current position of the end-effector to a predetermined position;
- determining a required position of a physical constraint based on the comparison of the current position of the end-effector to the predetermined position in order to prevent incursion of the end-effector beyond the predetermined position;
- and
- positioning the physical constraint at the required position.
An apparatus for guiding a user's control of an end-effector comprising:
- a robot having:
- at least one actuated joint,
- at least one other joint connected to the at least one actuated joint, and
- a physical constraint assembly movable by actuation of the at least one actuated joint, wherein the physical constraint assembly consists of a single physical constraint that limits the motion of the at least one other joint in only one direction;
- and
- an end-effector configured to be manipulated by an application of external forces and connected to the at least one other joint.
Dependencies are inferred from the claim text.