People with hemiplegia require ongoing rehabilitation exercises to regain function in their upper limbs. However, due to the increasing number of elderly and disabled people, the number of rehabilitation professionals is insufficient. As a solution to this problem, researchers have been exploring various upper limb rehabilitation exercise robots. Unfortunately, these robots are often large and heavy, making them cumbersome to wear and use. The proposed exoskeleton rehabilitation robot consists of two robotic modules: an elbow module (1 DOF) and a wrist module (1 DOF). In order to analyze the robot"s workspace, the kinematics were calculated using the D-H parameters. To generate the trajectories, five able-bodied individuals wore the robot and performed the hand-wash motion, resulting in a total of 10 trajectory data sets. The reference trajectories were then generated by polynomial regression based on the collected data. Lastly, a passive mode control was experimented with in the rehabilitation process, and the results demonstrated the promising effectiveness of the proposed robot.

The controller for the power assist robot that is in constant contact with the user requires to be sensitively controlled as per the user"s intention and maintain control stability to ensure the user"s safety. Admittance control is generally used for human intention-based force control. By setting the parameters of the admittance control at a low level it is possible to sensitively control according to the user"s intention. However, too sensitive settings make the system unstable. Therefore, it is difficult to set a fixed admittance parameter in a power assist robot in which dynamics change with an increase in load mass. Consequently, we propose a variable admittance control strategy according to the load mass. The proposed method responds sensitively to the user"s intention by setting the admittance parameters at low during no-load action and ensures stability by setting the admittance parameter high when transmitting high loads. In simulation with a carrying load of 30 kg, the proposed method requires half the interaction force compared with a fixed admittance control when decelerating and has twice faster settling time when stopped. In addition, through experimental verifications, the variable admittance control was proven to reduce the user"s load by 70% compared to load mass.

In this paper, we examine the exoskeleton robot which can support the muscular strength of the soldiers handling the front load and its applicability in the military field. In fact, in the questionnaire survey on the military applicability of exoskeleton robots, many soldiers reported that they felt immensely fatigued due to the heavy load on their back during the operation. Most of the exoskeleton robots in the military have been developed to reduce fatigue during the mobility and movement of soldiers. Research on the exoskeleton robots to support the waist has been carried out with emphasis on its role in assisting performance of repetitive work in the industrial field or the medical field. To examine the studies on conventional back support exoskeleton robots and to find out the functions required to apply a back-support exoskeleton robot to soldiers, we have classified the existing back support exoskeleton robots into power type, supported body, waterproof grades, and others based on weight, purpose, working time, etc. Apparently, the shape of the exoskeleton robot suitable for application in the military field and the required performance is presented in the present work.