Maneuverability Improvement by Feedback Compensation of a Physically Human-Interacting Robot with Variable Damping Control

Manufacturing workflows can be enhanced using the implementation of robots; however, it is limited to repetitive tasks, and a human operator is still needed to gain flexibility in the robot's movement. However, human-robot interaction can cause instability due to the robot's characteristics. The typical solution is to decrease the admittance parameter, but it also reduces the assisting effectiveness. Variable damping is another way to counter this problem, but if the instability problem isn't solved yet, the effect can be difficult to perceive. Our study aims to implement feedback compensation in the robot system to reduce the effect of actuator dead time and insufficient structural stiffness. The results prove that the implementation of feedback compensation can greatly improve the maneuverability of the robot by decreasing the force required during the traveling phase and increasing accuracy in the positioning phase, resulting in a task that can be completed with less effort and a shorter operation time.