Position control method for a planar Acrobot based on fuzzy control

A position control method for a planar Acrobot based on fuzzy control is presented. The system control objective is to control the endpoint position from any initial position to any reachable target position. Firstly, the state constraint relationship between the active joint and the passive joint can be obtained by employing the complete integral characteristics of the planar Acrobot. Next, another constraint relationship between the endpoint position and two angles of the joints can be obtained according to the physical structure of the planar Acorobt. Then, two target angles of the joints can be searched by using the particle swarm optimization algorithm based on the above two kinds of constraint relationship. Finally, a fuzzy controller is designed for the planar Acrobot, and it can achieve the control objective quickly. When the active link is controlled to the target angle by the fuzzy controller, the passive link is also controlled to its target angle because of the state constraint relationship. That is, the system control objective is achieved. Simulation results demonstrate the effectiveness and rapidity of the proposed method.