Development of a Walking Assist Machine Using Crutches – Motion for Ascending and Descending Steps

This paper discusses the motion of a walking assist machine using crutches when it is used to assist people with walking difficulties to ascend or descend steps. First, the basic composition of the machine, which is under development in the Mechanical Systems Design Laboratory in Tokyo Institute of Technology, is shown. Based on the features of motions for ascending and descending steps by a healthy person using crutches that were measured using a motion capture system, a parameterized velocity profile as the reference trajectory of the actuator in the machine is proposed. Values of the parameters are determined through dynamic simulation taking into consideration stability, consumed energy and user’s comfort. The effectiveness of the motion is discussed with experimental results.