Back handspring of a multi-link gymnastic robot - reference model approach

This paper reports on the first gymnastic robot that can perform back handspring. The robot is a planar and serially connected four-link robot, with its joints actuated by electric servomotors. The paper describes the modeling of the robot and the control framework for a back handspring. The controller is derived from a task-specific reference model and its model matching. The use of a reference model described by global physical quantities such as center of mass or angular momentum allows the gymnastic motion planning of a multi-body system to be intuitive and the model matching controller can be applied directly to the experimental model without obtaining each joint trajectory. The controller effectiveness is confirmed via simulations and experiments of the back handspring. Although there remains the problem of how to systematically design the control parameters, the paper shows the strength of the model-based controller for fast gymnastic motions.