Damage reduction of robot at the emergence crash by modifying stiffness

It is supposed that human and robot share living area in future. That time, the most important thing is security and safety of human. Robot have not injure human at any case. There are three ways for that. The first one is to control robot completely for fear that there is no emergency, which is almost impossible and dream of all engineers. The second one is to achieve smooth body like sponge. The third one is to insure soft joint actuation of robot like. Here the third method is studied using the pneumatic muscle actuators. The comparison between motor actuator and pneumatic muscle actuator is described and the method to configure robot manipulator using pneumatic mus cle is also explained. Sliding mode control is applied to control 2-link manipulator. Finally impulse from crash on obstacle is studied to show the joint stiffness modification effects. Dual arm simulator is used to assure the controllability of 2-link manipulator and the property of impulse at a sudden crash.