The Design Of The Self-balancing Two Wheeled Vehicle

In this thesis, a two-wheeled vehicle with the characteristic of self-balancing was developed. For the prototype design, the vehicle is arranged by two paralleled wheels and powered by electric motor, which is an unstable object needed force to keep balance, just as the traditional'inverted pendulum'. Since the action principle is similar to rocket flying and robot walking, this research is meaningful for the theory and practice.This self-balancing vehicle is composed of a pedal, a handle and two paralleled wheels. As the whole system, there is no control device, such as accelerator, retarder and brake, except one button for turning on/off. In the system, two inner hub motors are mounted on the both sides of pedal, and the battery with the drive-control circuit is positioned under the pedal. According to the inertial sensor (gyroscope, accelerometer), the monitoring data of pitching state and state changing are input into the MCU (Micro Control Unit) calculation for the acceleration commands to drive the motor forward/backward for the balance keeping. As a result, the vehicle would move forward or backward with the pitching of rider, and the velocity would be proportional to the tilt angle. For turning, different velocities of two motors would be carried out by the tilt angle of handle. In principle, as long as the power was adequate, the rider won't fall down which differ from the manual- balanced scooter. Above all, it is a vehicle of simple-structured, flexible and easy-controlled, which could be served as a convenient traveling tool to meet variety needs about transportation.For the posture monitoring system, the information solely depends on the gyroscope or the accelerometer couldn't make sure the balance of vehicle. So the signals from the gyroscope and accelerometer were integrated by a simple method of complementary filtering for an optimal angle to compensate the gyroscope drift error and the accelerometer dynamic error. Control technique is the core of vehicle movement, which is typical with PID (Proportion Integration Differentiation) technique in practice. PID moderator is a technology-matured moderator for wide application in continuous system, which based on deviation proportion, integration and differentiation. In this thesis, PID control technique was detailed investigated in theory, especially for the advantages of PID variational integration, and finally well-performance was achieved in the application.