说明：  日本九州大学的机械工程学院的 Xiong Xiaogang 于 2012 年提出一种更易于实现、同时有能够描述所有摩擦力现象的摩擦力模型，其基于一个微分方程和两个代数方程。本程序是其Simulink实现，非常好用。模型原理请参考：
(In 2012, Xiong Xiaogang of the school of mechanical engineering, Kyushu University, Japan proposed a much easier way. The friction model, which can describe all friction phenomena, is based on a differential equation and two algebraic equation. This program is its Simulink implementation, very good use. Model principles, please refer to:Xiong X, Kikuuwe R, Yamamoto M. A differential-algebraic multistate friction model[M]. Simulation, Modeling, and Programming for Autonomous Robots. Springer Berlin Heidelberg,2012)