HAL equipped with passive mechanism

Low back pain (LBP) is the serious problem in the field of nursing care. We have developed the HAL for lumbar support in order to reduce the lumbar load. For practical use, it is important to save energy of HAL. The purpose of this study is to develop HAL equipped with passive mechanism in order to reduce the power consumption of the HAL, and to verify the effectiveness of saving energy of HAL equipped with passive mechanism. The assist torque consists the actuators torque and the passive torque at the HAL equipped with passive mechanism. To verify the effectiveness of the HAL equipped with passive mechanism on lumbar load reduction, we simulated the motion assist evaluation by using the 3D skeletal model. In the HAL equipped with passive mechanism support, the stress onto lumbar was lower than without the HAL support. The experiment at task carrying a heavy load was performed in order to verify the effectiveness of saving energy of the HAL equipped with passive mechanism. The average power consumption of the HAL equipped with passive mechanism was reduced by 44%, and the maximum power consumption of the HAL equipped with passive mechanism was reduced by 45%. We developed the HAL equipped with passive mechanism in order to reduce the power consumption of the HAL, and verified the effectiveness of saving energy of the HAL equipped with passive mechanism. It is expected that caregivers can help an elderly person without the lumbar load during the care of bathing, and transferring from a bed to a wheel chair.