Designing a Stair Climbing Mechanism

During the last year I’ve been researching designs for robot locomotion platforms that can ascend steps while transporting a payload.  This is a much harder problem to solve than originally expected.  The challenge is that there are competing requirements.  In order to easily navigate hallways within a typical home environment a robot can’t be wider or longer than approximately 2 feet (assuming that the robot can turn on its central axis).  Anything wider than this and the robot can’t fit through a door; anything longer and the robot can’t navigate around box corners such as that found in a room entrance.  However, constraining a robot to 2’w x 2’l makes for a relatively narrow base to contain the center of gravity while ascending and descending stairs, especially while carrying a payload that might make the robot tipsy. Continue reading →