This study proposes two kinds of systems for building intelligent service robots, namely a sensor terminal named 'Portable' for making various personal mobility robots intelligent and a distributed sensor system for constructing an informationally structured environment consisting of laser range finders and active beacons. The sensor terminal Portable is equipped with a laser range finder and a gyro. Two types of personal mobility robot, namely standing type and wheelchair type, are made intelligent by installing Portable to provide navigation functions such as localization, obstacle detection, and path planning. The sensor system is mainly used to acquire position information about the personal mobility robots, obstacles, and moving objects (e.g., people); this information is used by Portable for navigation. The obtained information is transmitted to the robot, allowing it to operate in a complicated environment. The ability of the proposed system to navigate personal mobility robots is verified in two real environments.