Development of the walking support robot with the weight bearing mechanism supporting ischia - Cushion for ischia and behavior of ischia during walking

This report descries the cushion suitable for weight bearing mechanism supporting ischia and the behavior of ischia during walking. Hitachi Ltd. developed the power-assisted walking support device and the walk training machine with weight bearing mechanisms using a hip orthosis and a saddle. Because user's weight is centered on symphysis pubica, users feel sore and it is obstacle to smooth walking. Then, we propose a new weight bearing mechanism supporting ischia. Because an interface between human and robot is important, we experimented on the cushion for ischia that is the interface between human and the weight bearing mechanism supporting ischia. In the experiment, we measured seating pressure, the trajectory of the seating pressure's center, position of ischia, and force on the weight bearing arm when a user was walking while locating his hip on the cushion for ischia. The result shows that the seating cushion is suited for the interface, but it is also necessary to support separately each ischium's up down movement and rotating movement during walking.