Virtual Compliance Control of a Kinematically Redundant Serial Manipulator with 9 DoF

Kinematically redundant serial manipulators are currently used in industry either to avoid singular configurations or to increase dexterity. However, the surplus degrees of freedom of such mechanisms can also be used to ensure, or at least increase safety in a human-robot collaborative scenario. In this work the behavior of a serial manipulator with nine rotary joints is described where one joint module is equipped with a capacitive proximity sensor exemplarily. The compliance of the robot arm is realized by an impedance controller to achieve dynamic behavior, which simulates a spring-mass-damper system at one point of the kinematics chain. Usually, this enables the robot-arm to avoid, or at least reduce contact with an approaching human body and to continue its primary task simultaneously.