ROSPHERE – a spherical robot for exploration and monitoring

The Robotics and Cybernetics Research Group at the Universidad Politécnica de Madrid interest in development of robots able to move in environments with uneven ground ended up with ROSPHERE – a robot without wheels or legs which has a single spherical form and rolls itself to conduct the missions. During its assessment, the robot has shown great potential for exploration and monitoring.

Robot’s movement relies on an essential physic concept: the center of mass. The concept can be compared to a hamster running in the ball. As the hamster moves, it changes the location of the center of mass of the system and generates motion. The role of the hamster in spherical robots is taken by a mechanical system which is complemented with electronics instruments and programs which induce the motion of the ball in a controlled manner.

ROSPHERE has a pendulum system with a capacity of two independent motions. Thanks to this internal mechanism, the robot can conduct straight movements and similar curvilinear motion to a car. A significant part of time spent on this research was related to the development of mechanics, control electronics, communications and programming by generating two versions which were proved on evolutions of the pendulum and its drive system.

After the development of the test platforms and validation of its control systems, UPM’s Robotics and Cybernetics Research Group used the robot in different scenarios to assess its real applications. They managed to use the robot in situ to measure the environmental variables on the rows of crops, where the robot shape is suitable for rolling and gathering information that can be used to monitor the precision farming techniques.

The robot was also tested on shared spaces with people in order to verify that it can safely interact without being a threat to people. ROSPHERE has shown a great potential for different applications on its preliminary tests, and UPM researchers claim that improvement of its autonomous navigation or its mechanical strength could increase its versatility and application fields.

For more information, read the article published in Industrial Robot: An International Journal: “Moisture measurement in crops using spherical robots”.