Bond Graph Modeling and Control of Segway Using Principle of Inverted Pendulum System

Abstract

In the area of dynamics and control theory, inverted pendulum system is an interesting and classical control problem which is used as a standard for testing various new control strategies and algorithms. Inverted pendulum system is an excellent experimental platform to carry out research in the area of control theory and robotics. It is an under-actuated, nonlinear and unstable system. The control designing for such system is very difficult task. A personal transporter vehicle, called segway (Two wheeled inverted pendulum system) is also based on the stabilization principle of inverted pendulum system. The concept of segway is similar to the problem of balancing a broomstick on the end of the index finger. This thesis work presents the bond graph modeling and control of segway using the principle of inverted pendulum system. The work describes the bond graph model of inverted pendulum system with a nonlinear heuristic controller used as a swing up control and the PI controller as a stabilization control. The experimental validation of bond graph model of inverted pendulum system is given by comparing the bond graph simulation results with the experimental results. The bond graph model of segway is developed and control is developed using a PI controller. The bond graph simulation results for the forward and backward motion of segway are presented as pitch angle, speed of the vehicle with time. For the turning of the vehicle, Ackermann steering mechanism is adopted. The results of turning motion of the segway are also presented as yaw angle response of main vehicle body with time.