This paper presents a ceiling mobile robot platform which enables multiple robots to move smoothly and execute their own tasks in a living space. An advantage of this platform is potential to actualize sharing space between humans and robots and secure humans' safety, although the robots can access to humans when they need. For realizing the ceiling mobile robot platform, two key techniques are utilized. The first one is permanent magnet inductive traction method for the robots attaching under a ceiling plate, and the second is multi-robots simultaneous position measurement method using matrix of 2 dimensional codes. By experiments, feasibility and characteristics of permanent magnet inductive traction method are confirmed. And also practicality of position estimation method using matrix of 2 dimensional codes is examined.
