Development of a lightweight power-assist suit using pneumatic artificial muscles and balloon-amplification mechanism

Low back pain of workers is increased in workplaces that involve hard work. It is caused by excessive loading of the waist joint and muscle fatigue. Therefore, power-assist suits have been developed to decrease the load on the waist joint. However, previous power-assist suits have had problems such as low output or heaviness. Thus, we have developed an assist suit that is lightweight and exerts a large force. A balloon actuator and pneumatic artificial muscles are attached to assist suit as the actuators. The assist suit has various desirable features: lightweight, flexibility, and high output. First, human motion is analyzed for the development of the assist suit. The assist suit is developed to assist the waist joint torque. The assist suit is modeled, and the theoretical values of its generation force are estimated using an assist-suit model. Finally, the assist suit is evaluated by measuring the surface electromyography (EMG). The EMG of the wearer is compared with that without the suit. The effectiveness of the assist suit is confirmed by a decrease in EMG.