Abstract
In this paper,a variable impedance joystick for a novel robot operation interface is proposed.The joystick can change its mechanical impedance in real-time.The joystick is able to be applied as a haptic device for machine operation systems on operator's fatigue.However,if the impedance changes drastically,the operator is felt uncomfortable and its operability would get worse.Therefore,ratio of impedance changes without awareness is investigated by using knowledge of just noticeable difference(JND)
