通过扩张状态观测器估计摆杆角度及角速度，使用2 个跟踪微分器分别得到小车位移和速度及参考位移和速度，并将它们组合成控制量，实现了对摆杆偏角与小车位移的良好控制。(By using the extended state observer to estimate the angle and angular velocity of the pendulum, the 2 tracking differentiators are used to get the displacement and velocity of the car and the reference displacement and velocity respectively. They are combined into the control quantity, and the good control of the deflection angle of the pendulum rod and the displacement of the car is achieved.)