Development of a four-wheeled mobile robot system for bedridden patients

In Japan the number of severely crippled and bedridden patients who have to be completely taken care of with regard to daily routine is presently increasing for several reasons, and in addition the percentage of old-aged people in the population is growing. Providing care for these persons is becoming an extremely serious social and economic problem. With the aim of reducing the difficulties faced by handicapped people and those responsible for their care and nursing, we have undertaken research on the development of a four-wheeled mobile robot system to provide assistance in the daily activities of the bedridden and handicapped. The characteristics of this system are (1) front-wheel power steering and independently directly driven rear wheels, (2) one pair of manipulators which have nine degrees offreedom mounted on the four-wheeled mobile device, and (3) a hierarchical control system with one 16 bit and several 8 bit microcomputers. We utilize a teaching-playback method to develop control programs for specific activities. As a result of our research and development, we have succeeded in establishing fundamental techniques for mobile robot systems for bedridden patients.