High-speed Servosphere

Servo-spheres are robotized observation systems that produce unbounded fields for behavior observation of wandering animals. Each Servo-sphere is a vision-based control system that mainly consists of a camera, a sphere, and motorized omniwheels. As an approach to achieving high observation performance of Servo-spheres, this paper first proposes a fast control technique under installation of a high-speed camera. No special devices other than a high-speed camera are required. The proposed technique improves the time resolution without changes in the spatial resolution. This paper also investigates performance of a Servo-sphere with changes in the camera frame rate and the control gains. It is demonstrated that the regulation errors are significantly improved by the proposed technique at the high frame rate with high gain feedback. High gain feedback at the normal frame rate sometimes produces undesired oscillations, and it does not decrease regulation errors. The results imply that the high-speed Servo-sphere improves observation performance, while normal Servo-spheres might lead to an erroneous conclusion on animal behavior.