中文说明：本文实现二级倒立摆数学模型的推导，状态空间描述以及状态反馈和状态观测器的实现！比较有无状态观测器对系统运动的影响！
English Description：
This paper realizes the derivation of the mathematical model of the double inverted pendulum, the description of the state space and the realization of the state feedback and state observer! Compare the effect of state observer on system motion!