Abstract
Current wearable robots mostly focus on applications in military, rehabilitation and load lifting in the health sector, while they are hardly used in industry and manufacturing. In this paper, a sensor and control concept for a wearable robot for assistance in manual handling of loads in industry is presented. Special requirements such as low costs, direct contact between the human and the load and easy set-up are addressed. A wall-mounted test stand of an actuated elbow joint was built up to evaluate the proposed sensors and control algorithms. By using a torque sensor in the elbow joint as reference it is shown that low cost force sensors in the forearm can be used to measure the human-robot interaction. A torque-based and a velocity-based impedance control approach are compared which allow the user to move freely while not handling any loads and which also allow to incorporate a human command signal for regulation of force support. The former is shown to be superior to the position-based approach. Further, the influence of the human impedance characteristics onto stability of the controllers is discussed.