The main purpose of this paper is to describe a head-controlled human-machine interface system that can help people who can not use their hands to manipulate a device. Our study is to design a head-controlled human-machine interface system. Users can issue four different commands with the tilt of their head forward, backward, leftward, or rightward. We utilize a head-controlled cont roller designed by ourselves to control a self-propelled vehicle to go forward, go backward, turn left, or turn right to verify the feasibility of the head-controlled human-machine interface system.