Developing Of A Dual-wheel Self-balancing Vehicle Using Double PID Cascade Control

The dual-wheeled self-balancing vehicle is a leading field in the research of various control methods because of its dynamic system of multi-variable,nonlinear,unstable and strong coupling,so the development of self-balancing two-wheeled vehicles has attracted widespread attention.The dual-wheel self-balancing vehicle can be analyzed by using inverted pendulum model.The system is extremely unstable,so it is important to use a effective method to maintain its stability.The system is mainly composed of three parts: attitude sensing subsystem,CPU processing subsystem and driving subsystem.The accurate attitude information and the algorithm which gets the data to be fused and processed determine the performance of self-balancing vehicle.The self-balancing vehicle detects operating conditions through the real-time high-frequency sensor(MPU6050),the collected pitch angle and acceleration rate of change is transmitted to the CPU,CPU fusion processing and output adjustment attitude commands,which drive the motor to make two wheels' speed change to achieve the purpose of acceleration,deceleration and balancing the body.In this paper,a dual-wheel self-balancing vehicle using double PID cascade control is developed.Using STM32 as the cord board and motion detection sensor(MPU6050)detects angular velocity and angle in real time.And performing data fusion by complement filter to reduce the influence of the temperature drift of the sensing signal.At the same time,even if the self-balancing vehicle suffers from great external interference(Push and pull,vibration,bump,etc.)can also be quickly adjusted.The system controls the vehicle body through the Proportion Integration Differentiation(PID)algorithm.By the control of PD(Proportion Differentiation),the vehicle body can be erected.The speed and direction of the motor are fed back in real time by the speed encoder installed on the DC motor.And using the control of Proportion Integration(PI)to control the body speed.The TB6612 FNG driving system of motor is used in the self-balancing dual-wheel vehicle,and the motor speed is changed by adjusting the PWM output duty cycle.The system is powered by the LM2940 and the ASM1117 subsystem,which can convert voltage accurately,power the STM32 and the motor.Finally,two-wheeled self-balancing vehicle upright balance operation is achieved by adjusting and optimizing the control parameters.