Input shaping and strain gauge feedback vibration control of an elastic robotic arm

Novel robotic applications, such as service robots, support the interaction between a human and a robot within the same workspace. These types of cooperative tasks require a safe robot operation in order to avoid physical harm to the human operator. In case of contact between the robot and human inherent safety is accomplished by means of lightweight flexible structures of reduced mass and stiffness that absorb contact forces. The flexible structure induces vibrations of the arm during motion, which complicates the precise kinematic control of the end effector pose. This contribution proposes input shaping in conjunction with strain gauge feedback control to suppress and compensate arm vibrations induced by robot motion. The control schemes are experimentally verified and the results demonstrate an efficient damping of link vibrations.