Balancing and swinging-up control for cart-pendulum-seesaw system by decomposed fuzzy coordination control

Using a combination of the cart-seesaw and the inverted pendulum system, this paper presents a novel laboratory apparatus called the cart-pendulum-seesaw (CPS) system. The proposed pneumatic CPS is a classic example of a super articulated mechanical system. The resulting system has two inputs: a force applied to the cart and another force applied to the loading cart which tries to balance the seesaw test-bed. With two inputs and four available for the measurement outputs, the unstable multi-input-multi-output system offers an interesting control challenge. This study breaks down the system into several tasks, one for pendulum swinging up and the other for seesaw balancing. The pendulum is first swung up; then, balancing the pendulum at the upright position with a fuzzy controller, the seesaw is balanced by another fuzzy controller. This study incorporates a fuzzy coordinator into the seesaw system to take control action in extreme situations. The experimental device is used to evaluate the efficiency of the proposed methodology. Unlike other model-based methods, the proposed fuzzy control methodology does not need an accurate measurement of all state parameters; moreover, it is robust for parameter changes and other disturbances in the system.