Control for Mobile Inverted Pendulum Using Sliding Mode Technique

Abstract

In this thesis, a mobile inverted pendulum system is considered. A control system pilots the motors so as to keep the system in equilibrium. The mobile inverted pendulum is a system with an inverted pendulum attached to a mobile cart with two coaxial wheels, each of which is coupled to a DC motor. The dynamic equation of the mobile inverted pendulum is established. To stabilize the mobile inverted pendulum, a stabilizing controller via sliding mode control is designed based on Ackermann’s formula, which obtains a sliding surface in explicit form as well. The control law is designed to make quick converge to the state of the closed-loop system during the control process. The overall control system is described. The servo controller using two microcontrollers PIC16F877 is introduced. Moreover, the configuration using Lyapunov function is presented to control the speed of a DC motor. A configuration for sensors including tilt sensor and two incremental encoders is developed to obtain the system states and realize the above proposed controller. These measurements can then be fed back to the controllers to impose the desired closed loop dynamics. The simulation and experimental results are shown to prove the effectiveness of the proposed modeling and the stabilizing controller.