Noncontact Impedance Control for Redundant Manipulators

This paper proposes an impedance control methodthat can regulate a virtual impedance between a robot manipulatorand external objects using visual information. Theconventional impedance control method is not useful in somecases where no interaction force between the arm and its environmentexists, although it is one of the most effective controlmethods for manipulators in contact with the environment. Usingthe proposed method, we can control the manipulator motionbased on the virtual impedance before contact with the objects.The validity of the proposed method is verified through computersimulations and experiments using a direct-drive robot

An Obstacle Avoidance Method for Action Support 7-DOF Manipulators Using Impedance Control

An obstacle avoidance method of action support 7-DOF manipulators is proposed in this paper. The manipulators are controlled with impedance control to follow user's motions. 7-DOF manipulators are able to avoid obstacles without changing the orbit of the end-effector because they have kinematic redundancy. A joint rate vector is used to change angular velocity of an arbitrary joint with kinematic redundancy. The priority of avoidance is introduced into the proposed method, so that avoidance motions precede follow motions when obstacles are close to the manipulators. The usefulness of the proposed method is demonstrated through obstacle avoidance simulations and experiments