Design and implementation of a stair-climbing robot

Taiwan and other developed countries have being experienced an emergence of a growing aging population. Home-caring robot is an excellent candidate capable of supporting such an aging society. In the paper, a robot is designed to move up-and-down stairs to provide service for the elders. The robot consists of a main body for moving, a front arm and a rear arm for moving up and down stairs. The main body is equipped with two brushless dc motors (BLDCMs) and their drives for locomotion, worm gears for torque amplification, two dc motors to control two arms, and DSP-based board as control center. The robot is equipped with roller chains attached with rubber blocks used to generate friction with ground and stairs for moving. The distance between any two rubber blocks is properly arranged to fix the stair brink. The moving direction of the robot is steered based on the speed difference of two BLDCMs and the information from ultrasonic sensors. A walking experiment of moving up and down stairs with the rise of 120 mm and depth of 400 mm is shown in the video.