The first step to system modeling and control is input selection. 系统建模与控制的第一步是输入变量选择。
Generally the inverted pendulum system is modeled as a linear system, and hence the modeling is valid only for small oscillations of the pendulum. 通常倒立摆系统建模成一个线形系统，因此模型只对小幅度摆动的摆才有效。
