Development and Control of Underactuated Parallel Rotary Double Inverted Pendulum System

The Parallel Rotational Double Inverted Pendulum System (PRDIP) is a new model in the pendulum family. And there are not many articles that propose and research this model at the moment. One of the interesting features of the PRDIP system is the presence of an underactuated link, which makes it challenging to control the system. This type of system has received increasing attention from researchers in recent years due to its applicability in many areas, such as robotics and control. This model is built by adding one more link parallel to the former link, which is placed at the ends of the arm. Because of the complexity of PRDIP, this model has not been widely proposed and investigated in both simulation and experiments. Therefore, this research is going to concentrate on investigating the PRDIP system and deploying Linear Quadratic Regular (LQR) algorithm in simulation and experiments for this system. The LQR controller is responsible for controlling and maintaining an arm and two pendulums, which work around the work points. Particularly, the working points of the two pendulums are totally different. The long pendulum will be controlled around the upward upright position, the short pendulum will be controlled around the downward upright position, and the arm will be controlled in a particular position. The result of this research shows that the LQR algorithm has been successfully deployed for the PRDIP system.