To assist elderly people with physical disability, an autonomous mobile system has been needed. Wehave been studying the method to navigate such a mobile for institutional care. Installation of this autonomous mobile has to be easy. Therefore we use light markers to guide the mobile. The markers are fixed to the ceiling at certain intervals. A powered wheelchair is driven according to the position of markers taken by a CCD camera with a wide angle lens. The field of view of the camera is divided using mirrors to get images in multiple directions concurrently. Since our system will be used in the institutes for elderly people, we assume that the environment is structured. From this assumption, all expected obstacles are walking persons around the mobile. To detect persons on the way, ultrasonic range finders are equipped to the front of the mobile. A prototype software to control the wheelchair was developed. Evaluation in an experimental configuration showed that our system can improve the quality of life(QOL)of elderly people, as well as decrease the burden of carers.