A hybrid control policy of robot arm motion for assistive robots

Tele-operated robotics has been widely-used to manipulate heavy or hazardous objects in an unknown or dangerous environment. Nowadays, it is adopted in assistive robots to help the elderly in accomplishing household tasks. This paper proposes a hybrid control policy of robot arm motion to semi-automatically control a remote robot arm, which differs from previous work in its hybrid control policy. The motivations of the proposed hybrid control policy are rooted from (1) the safeness in controlling a robot arm in an uncertain environment by tele-operating the robot far from the target position; (2) the quickness in automatically controlling the robot arm close to the target position. By doing this, the robot arm is manipulated to quickly and safely reach to the target position. The proposed hybrid control policy tele-operates a robot by utilizing the joint angles of a human arm to remotely control the robot arm posture where the human joint angles are captured by the proposed motion capture method. To validate the proposed method, we conducted the experimental work on an 6 degree-of-freedom humanoid robot arm. The results showed that the human was able to safely and quickly reach to the manipulative objects by the proposed hybrid control policy of robot arm motion.