PID control and implementation of the inverted pendulum of the trolley

  The study of the inverted pendulum system is a comprehensive problem that integrates multiple disciplines. It combines knowledge of intelligent robot technology, control theory, computers and other related aspects. At the same time, it is also a classic experimental platform to verify the effectiveness of various control strategies, especially In practical engineering applications, research on the inverted pendulum control algorithm can solve many practical problems similar to the inverted pendulum model. This project designs a cascade PID controller for the problem of stabilizing the inclination angle of the inverted pendulum pendulum of a car and the speed of the car. Simulation experiments and physical experiments verify the effectiveness of the control algorithm.

  By setting the physical parameters of the device, the Simscape simulator is used to establish the physical model of the inverted pendulum of the car. Using cascade PID as the control method, the physical simulation of the trolley inverted pendulum system was carried out, and the simulation results were analyzed. The Newton - Euler method is used to mathematically model the inverted pendulum of the car, and the transfer function and state space equation of the inverted pendulum of the car are obtained. At the same time, the Lagrangian method is used to verify the established mathematical model , and the advantages and disadvantages of the two modeling methods are analyzed. Model the car motor, and the modeling process strives to be close to the actual physical system. Analyzing the mathematical expression of the PID control algorithm and inspired by angle and speed control, a cascade PID control method was designed and Simulink under Matlab software was used to verify the designed control algorithm.

  After completing the theoretical part, we started to build the actual model, using STM32 microcontroller as the control chip of the system, WDD 35 D 4 as the angle sensor , two DC motors as the power unit, and using an encoder to measure the motor speed in real time. The controller receives the input angle and speed signals, outputs PWM signals, and adjusts the motor speed through the motor drive module to ensure system balance. The lithium battery is used to provide power, and the voltage of the lithium battery is converted into the voltage signal required by the sensor and controller through the voltage step-down module. Use the Bluetooth module to establish wireless communication with the host computer device, and you can check the operation of the system and change the values ​​of control parameters on the host computer. Use Jialichuang software to layout and design the schematic diagram and PCB of the system hardware. In terms of software, C language is used as the logic function development language, Keil5 is used to program the software, and ST-Link is used to program the program . After the system is assembled and powered on, the control parameters of the system are adjusted and optimized through the Bluetooth module to finally achieve the goal of balanced operation of the inverted pendulum system of the car.

I was deeply moved by doing this inverted pendulum project. It is very difficult to transform theoretical knowledge into practical projects. I have basically used all the professional courses I studied in college. Sure enough, the knowledge I learned in college is quite useful. If you are interested, you can read my paper. Please correct me if there are any errors.