Design And Of Two-wheeled Self-balancing Robot System

The two-wheeled self-balancing robot is a novel kind of wheeled mobile robot, whose structure is a combination of a wheeled mobile robot and a inverted pendulum system. The two-wheeled self-balancing robot is a typical strong-coupling, natural unstable non-linear system. So it is an ideal test platform where various control methods can be studied. Meanwhile, the robot will be very useful because of its flexible motion, especially in the field of personal transporter. The subject aims to develop a two-wheel self-balancing robot.Firstly, this paper presents a design scheme to build a self-balancing robot. The gyroscope and accelerometer are used to monitor the attitude of vehicle. Then the A/D convertor in AVR controller converts these analog signals into digital signals. The AVR controller processes these data by some control algorithms and generates PWM signals. Through a H-bridge circuit, two DC motors are driven to balance the vehicle.The state-space equation is obtained through the mathematical model which is established by the analysis of kinematics and dynamics. From the stat-space equation, we can clearly find that the two-wheeled self-balancing robot is a unstable and nonlinear system.In this system, the measure of a tiled angle has direct influence on self-balancing control performance. This paper presents a method based on Kalman filter to fuse data form a gyro sensor and a tilt sensor. In order to test the algorithm, a test platform is built and in it the data form will encoders be considered as a more precise sensor to measure the tilt angle. The tests have shown that the method can compensate for the defects of the two sensors and estimate attitude effectively.At last, the motion of the system is devided into two separately motions:the self-balancing motion and steering motion. This paper mainly discusses the problem on the self-balancing motion. To Meet the requirements, state feedback control method and pole placement algorithm are introduced and the results are quite well.