Many human movements can be aided by exo-suit. One of them is that humans put a lot of strain on their knee and waist joints while lifting large objects, but using an exo-suit can lessen the risk. However, since the weight of the exo-suit itself acts as an additional burden on body, an appropriate torque distribution strategy considering the entire system is necessary. To solve this problem, this paper proposed an assistive technique based on whole-body control. Meanwhile, when the legs are fully extended during torque control, the system has a singularity problem and the required torque will be highly increased. Singularity is serious problem because it is essential to fully straighten the legs during the lifting operation. In this paper, this problem was solved by adding a straight-leg term to the whole-body control cost function. The feasibility of the proposed method was verified through simulation, and it was shown that the exo-suit could stably perform lifting motions due to the method.

For years, crane, a chain block, an elevator and a forklift truck have been developed and used to carry heavy loads, but manpower needed where heavy equipment use is not practical. Aging workers suffer from musculoskeletal disorders, and are helped by developing various muscle assisting wearable robots. Industrial wearable robots must meet the payload capacity required for the pilot"s overall operation to ensure safety and operational performance. However, the payload capacity of wearable robot using rotary actuator or linear actuator at the knee joint decreases dramatically in the knee-flexion posture, with reduced moment arms. To solve this problem, the author recommends using Single Acting Hydraulic Telescopic Cylinder Electro Hydrostatic Actuator (SAT-EHA) to increase the torque of the knee in the knee flexion position. The characteristic of telescopic cylinder is high speed in 1st stage and high force in 2nd stage. The Human Universal Mobility Assist-Hybrid (HUMA-H) was developed by designing and fabricating the waist joint to balance the front and rear directions using an electric motor driver. As the payload capacity increases, the robot pilots can squat and stand up with heavy loads. The performance was verified through the operation test and respiratory gas analysis test of the manufactured HUMA-H.