Abstract
The number of people who need of nursing care become difficult to various activities of daily living is increasing. The movement to stand up has much frequency in particular in daily living. And standing up action causes pain to the joints as people get older. In this research, we develop the device whose seat plate follows a motion of the thigh in general standing up action for the purpose of relieving the burden of the joint and reducing a care worker's effort. The device is designed using a planar five-link mechanism and a gear train, only one input is needed to drive the device. The lengths of links are determined by method of comparing the motion of the seat plate of the device with the motion of human thigh in standing up action. And this device is expected to make users stand in a natural form also in the state when the body is left to seat plate, and to guide the subjective standing motion of users.