The purpose of this research is to assess an applicability of wearable robot for the shipbuilding works. We developed two types of wearable robot that can be separated by actuation mechanism; one is directly actuated by electric motors and another is actuated by electro-hydraulic actuators. The lifting capacity of both of the robot is currently about 30kg. We performed field tests in 7 kinds of workplaces for handling and installing heavy-weight objects such as pipeline outfitting components, small metal components, and heat insulation box for two weeks. We focused on whether the wearable robot is applicable to rough and tough shipbuilding environments which include bumpy and sloped metal terrain, steep and narrow staircase, longitudinal stiffener. From the experimental result we verified that the wearable robot could be helpful for assisting workers in several shipbuilding workplaces. We also assessed what should be improved for the application based on the worker's requirements.

While compliance control scheme is done for the wearable robot combined with the linear actuator and sensor on it as intended by the user, oscillations occur due to the joint kinematical mechanism. In this paper, the cause of oscillation on the knee joint is analyzed in detail. Also, it is shown that the moment arm is varied with joint angle, it is confirmed that sensed pressure is changed by the variation. In addition, for canceling the oscillation, torque sensor -using the method to move its force/pressure sensor position from the cylinder to the joint, and a wire-pulley system that adjusts the moment arm with a mechanical impedance compensation are proposed. Finally, simulations and experiments are done for demonstrating oscillation reduction by using the DSME wearable robot.

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A wearable robot with linear actuators is required to maintain over the desired payload over whole range of knee joint angle even when the user is walking, sitting down/standing up while holding up weights. However, in knee-flexion posture, the lifting payload at the knee joint decreases drastically by the moment arm of linear actuators and the cosine of joint angle. In order to solve the problem of the payload decrease, the sub-links attaching on actuators and the sub-link with shank bending method are proposed. As the result, two methods are successfully proved to increase the payload by simulation.