Robust impedance-matching of manipulators interacting with unknown environments
AssigneeCanadian Space Agency
InventorFarhad Aghili
Life of this patent
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Abstract
A system for replicating the behavior of a target robotic manipulator with respect to a payload and worksite, has a real-time simulator capturing the dynamics of the target robot manipulator; a mock-up of the payload and worksite; and an emulating robotic manipulator for interacting with said payload and worksite. The emulating robotic manipulator is controlled by the real-time simulator in a control loop to replicate the dynamical behavior of said target robotic manipulator in its environment by matching the impedance of the emulating robotic manipulator with that of the target robotic manipulator.
Claims26
A system for replicating the behavior of a target robotic manipulator with respect to a payload and worksite, comprising:
- a real-time simulator capturing the dynamics of the target robot manipulator;
- a mock-up of said payload and worksite;
- and an emulating robotic manipulator for interacting with said payload and worksite;
- said emulating robotic manipulator being controlled by said real-time simulator in a control loop to replicate the dynamical behavior of said target robotic manipulator in its environment by matching the impedance of the emulating robotic manipulator with that of the target robotic manipulator.
A method of replicating the behavior of a target robotic manipulator in its environment using an emulating robotic manipulator, comprising:
- applying a motion control law to the emulating robotic manipulator with sufficient bandwidth to allow adequate maneuvering in free space;
- obtaining the impedance of the target robotic manipulator;
- obtaining experimentally the open-loop admittance of the emulating robotic manipulator;
- and matching the impedance of the target robotic manipulator and emulating robotic manipulator.
A method for replicating the behavior of a target robotic manipulator with respect to a payload and worksite, comprising:
- providing a mock-up of payload and worksite;
- providing an emulating robotic manipulator which emulates the performance of the target robotic manipulator while interacting with said mock-up of the payload and worksite;
- and controlling said emulating robotic manipulator with a real-time simulator to maintain an endpoint pose of the emulating robotic simulator coincident with that of the target robotic simulator by applying a rheonomic constraint to the simulator.
A force feedback controller for an emulating robotic manipulator of a target robot, wherein, said force feedback controller is configured to:
- (i) build a parametric uncertainty model based on the range of variation on the stiffness and damping values in the environment;
- (ii) determine the open-loop frequency response of the emulating robot manipulator from a sequence of input-output data obtained by excitation of the emulating robotic manipulator in contact with the environment;
- (iii) compute the coefficient of a fixed transfer function to match the observed input/output behavior;
- and
- (vi) build a linear fractional transformation model based on a performance specification and the uncertainty model to achieve desired impedance and ensure contact stability.
Dependencies are inferred from the claim text.