A novel energy pumping strategy for robotic swinging

In this work we show that an Acrobot can be made to behave as a robotic swing. This is achieved by contI'oIling the first joint, provided that a given condition is satisfied. When this condition is not satisfied, the system undergoes through singular points. Even when this happens, we are again able to make the system behave as a swing by controIling the second joint and employing a new Energy Pumping stmtegy. This stmtegy presents impOrtant advantages compared to previously Proposed stmtegies, as it is the only one that can start the system frOm rest and drive it to large heights. MOreover, it is fast and requires very small torques.