경사면 이동도립진자의 안정화를 위한 슬라이딩모드 제어기 설계

Abstract

The mobile inverted pendulum replaced by human being must keep its balancing and autonomous control, move forward, backward and turn on a flat plane and an inclined plane. This thesis presents a sliding mode controller to stabilize the mobile inverted pendulum on a flat plane and an inclined plane which can move forward and backward and turn. It also presents development results of the mobile inverted pendulum as follows. The mobile inverted pendulum is composed of an inverted pendulum and a chassis with two coaxial wheels. The nonlinear dynamic modeling of the mobile inverted pendulum is derived using Newton formula. The derived nonlinear dynamic modeling of the mobile inverted pendulum is linearized. The decoupling method is also presented to control the rotation around the z axis independently of the rotation around y axis. It transforms torques of y and z axis into the wheel torques. Based on the linearized dynamic modeling, a sliding mode controller is presented to stabilize the mobile inverted pendulum that can move forward and backward, and turn on the flat plane and inclined plane. To design the sliding mode controller, a switching function is defined based on a sliding surface matrix and state variable vector. The sliding surface matrix is designed based on an optimal control theory to minimize the quadratic performance. A control law is designed to stabilizing a switching function using reachability conditions to the sliding surface. A control system to implement the designed controller is developed based on TMS320F28335 microcontroller. To obtain information of the mobile inverted pendulum state variables, the following sensors are used: encoder, gyro sensor and accelerometer. The angle of the mobile inverted pendulum is measured using the gyro sensor and the accelerometer. The complementary filter is designed to compensate a gyro sensor’s accumulative error and to fuse with gyro sensor and accelerometer. The mobile inverted pendulum is manufactured to experiment the proposed controller. Finally, the simulation and experimental results are shown to prove the effectiveness of the proposed controllers.