Control Study Of Virtual Inverted Pendulum System

Inverted pendulum is a typical unstable system of multivariable, nonlinear and over coupling, and is a typical controlled object used in the experiment of automatic control principle and computer control in colleges and universities. It has important use in experiment education and the study of control theory.A design scheme of virtual inverted pendulum is introduced in the paper. The inverted pendulum mathematics model is achieved by using software. While the state variables are changed to sensor signal by using hardware circuits. Hardware and software are used all together to build inverted pendulum semi-physical model. The scheme offers simplicity of design and intuitive image. The control arithmetic can be achieved easily. The control process can be showed dynamically. The scheme will be widely used in the study of control algorithm, experiment, teaching and practical engineering.After analyzing the research and development actuality, the system scheme is introduced in the paper. The single chip of C8051F020 is used as controller to design hardware platform. The math model derivation process was founded with Newtonian mechanics in this paper, and the virtual inverted pendulum transfer function and state space equation is got.The mathematics model is achieved by MATLAB which has strong arithmetic capability. The variables actual value is changed to sensor signal by using the hardware circuits which produces control data. The serial communication and data transmitting is achieved by VB program. The cartoon interface is designed by the Kingview software. The interface can show the control process directly and form variable curve to record and compare. DDE protocol was used to solve the problem of data sharing among MATLAB, Visual Basic and Kingview.Finally, the controllability and observability of the system were analyzed. The control strategy was also analyzed in the paper and pole assignment, PID and LQR algorithm were used to give the simulation and the response curve of the system. The influence of mass of the cart and length and mass of the pendulum to the dynamic characteristic of system was analyzed.