The Application Of RBF-ARX Model-based Predictive Control On Inverted Pendulum System

The inverted pendulum system is a natural instability system of multivariable, nonlinear and strong-coupling. The research of the inverted pendulum is always a hotspot in control field in recent years. As a controlled object, it has very important value, not only the theory but also the realistic meaning in the research such as the walking of biped robot, the lunching process of rocket and flying control of helicopter. Predictive control based on RBF-ARX to inverted pendulum system will be presented in this paper.Firstly, based on the Physical model of inverted pendulum system, the characteristics of the inverted pendulum system were analyzed. Some modeling and control strategies of inverted pendulum were compared. According to the non-linear characteristics of the inverted pendulum system, predictive control based on RBF-ARX would be used to control the inverted pendulum system.Secondly, the structure and principle of the RBF-ARX model was introduced, and the identification, optimization and selection of model's parameters were analyzed and explained in detail. The data which can describe the dynamic characteristics of inverted pendulum was sampled. The RBF-ARX model of the inverted pendulum system was set up after estimating the parameters off-line by SNPOM. At last, the RBF-ARX model and the ARX model with the same order were compared. The results showed that the RBF-ARX model had a small error and higher modeling accuracy.The RBF-ARX model-based predictive control strategy was designed based on the basic principle of predictive control and then the realization of the control strategy, the selection of the parameters and the designing of the system were introduced in detail. Meanwhile, a simulation experiment was carried out in Simulink. Based on the simulation experiment, the application of PID control and the RBF-ARX model-based predictive control to the real inverted pendulum system were compared, the control performance of predictive control based on RBF-ARX is much better than that of PID control. The results shows that this control method is effective to the inverted pendulum system. This control method provides an effective solution to the control of complex nonlinear systems.