具有输入饱和的轧机液压伺服系统鲁棒自适应控制

针对具有参数不确定、非线性和输入饱和问题的轧机液压伺服位置系统，提出一种鲁棒白适应backstepping控制策略。首先，定义一个光滑函数估计饱和函数；为获得稳定的控制输入信号，对被控对象进行增维。其次，利用backstepping方法进行控制器的设计，其中，为处理估计函数的偏微分引入了Nussbaum型函数。最后基于Lyapunov方法证明了闭环系统的所有信号是一致终结有界的。仿真结果表明，该方法能够有效抑制输入饱和对系统造成的不良影响，并能保证系统对参数慢时变具有较强的鲁棒性。

Robust adaptive control for rolling mill hydraulic servo system with input saturation

A robust adaptive backstepping control method is proposed for rolling mill hydraulic servo position system, which con- tains uncertain parameters, nonlinear characteristics and input saturation. Firstly, a smooth function is used to approximate the saturation. The plant is augmented in order to obtain stable control input signal. Secondly, backstepping method is used to design controller. A Nussbaum function is introduced to deal with the derivative of the approximate function. Finally, Lyapunov method is used to prove that all the signals in the closed-loop system is uniformly ultimately bounded. Simulation results show that this method can not only suppress the harmful effect which input saturation causes effectively, but also ensure good robustness for system parameter slow time-varying.