The result of this work is ROSPHERE, a robot without wheels or legs which has a single spherical form that, literally, scrolls by itself to conduct the missions and being inherently stable. The robot has proved its potential for diverse applications during the assessment.
How can a single ball be able to move apparently without any external force? In this case, the performance is based on a principle of relative simplicity involving the understanding of an essential physic concept: the center of mass.
The running of the “spherical robot” can be compared to the ball game thought for hamsters. In that case, as the hamster moves it changes the location of the center of mass of the system by destabilizing the spherical robot and consequently generating motion.
In general, the numerous motion systems of spherical robots can be understood as alternative ways to replace the little animal with a mechanical system which is complemented with electronics instruments and programs in a way that, as a joint, the "mechatronic" system may induce motion of a ball in a controlled manner.
ROSPHERE, the prototype developed by the Cybernetics Research Group of the UPM, for example, has a pendulum system with a capacity of two independent motions. Thanks to this internal mechanism, ROSPHERE can conduct straight movements and similar curvilinear motion to a car.
A significant part of time spent on this research was related to the “mechatronic” development of the robot, this includes all the aspects that involve its mechanics and control electronics, communications and programming by generating two versions which were proved on evolutions of the pendulum and its drive system.