Development of Hybrid Power Supply System for Mobile Robots

A trend toward robotic research has shown that mobile robots nowadays play more important roles in service tasks than ever. Mobile robots have been changed in their sizes a lot from gigantic instruments in manufacturing plants, as in the past, to the moderate machines in todayfs office building, hospitals or houses. However, mobile robots are kept away from being compact because the weight of onboard batteries become a constraint toward the size and weight of robots itself. Given the technology of today, a battery-driven robot cannot work for long on a single charge. Development of a new powerful technology for batteries may take many exhausted years.

In this research, a dual-energized scheme called HYbrid POwer Supply (HYPOS) methodology has been proposed. During the specified missions, the electricity for mobile robots is available from two types of energy sources; battery and household electricity. The technique is that a robot is supplied by household electricity through an electric cord during a task execution and to reduce the effects of electric cord, we attempt to use a short cord and let the robot change connections between multiple outlets autonomously. The robot is allowed to find and connect to a household electric source by supplying of an onboard battery. The significant of HYPOS system is that a HYPOS robot can work during recharging a battery. The challenge of implementing HYPOS system is to develop the outlet-connection procedures and to handle the electric cord to reduce movement disturbance.

Instead of developing a robot with full faculties, we let the environment provides some of them to help the robot. We have developed a special device call Power Supply Station (PSS) attached to the conventional outlet and let the robot connects to PSS instead. A cord-winding system has been developed on the robot and cooperated to the movement of robot. An experiment on sweeping task has shown that a HYPOS robot can work consecutively for long hours without breaking the operation for recharging the battery. The efficiency of HYPOS from the viewpoint of energy consumption is satisfied.

Keywords: Power Supply, Battery Problems, Service Robot


  1. Chatchai Wattanasin, et al.: A Hybrid Technique to Supply Indoor Service Robots, In Proc. the 1998 IEEE Int. Conf. on Robotics and Automation, Leuven, Belgium, May 1998 (to appear).



Fig. 1 Prototype HYPOS System                 Fig. 2 Image of HYPOS Concept