Control of gymnast on a high bar

Fundamental problems in controlling a gymnast robot to do stunts on a high bar are discussed. To increase swing amplitude there are two methods. One is to pull up and pull down the mass center of the whole body. The other is to oscillate swing by sinusoidal joint movement at the eigenfrequency of the pendulum. But oscillation in constant frequency cannot make the gymnast robot go up beyond horizontal position and do a giant swing. A new oscillating method by changing oscillating frequency according to swing amplitude without sudden change of joint angles is proposed. This method is compared with the first method by simulation and by experiments. Control algorithms to maintain a handstand state on a high bar after some giant swing rotations are also developed by simulation