Experimental researches using small-sized humanoid robots enable researchers to realize whole-body behaviors and visual-auditory interaction behaviors in a real world. In these experiments, it is important for each researcher to make a trial by using of humanoid robots in various ways. Therefore, a robot system that is able to realize robots with various sensors and actuators easily is important. In other words, an extensible robot system is required that has no limitation of the number of devices and that is easily add addition devices to an existing on-body robot system.

We propose a simple and an extensible robot system using bus connected intelligent device units that each device has a processor. This system enables researchers to build a robot with a number of devices and to add additional devices without significant changes of existing software and hardware structure. In a sense, this architecture realizes a rapid prototyping environment for building robots.