基于上界估计的变参数Lorenz系统模糊滑模控制

摘要

传统滑模控制设计方法根据系统不确定性上界函数得到的切换增益,不能随着受控状态的变化而相应变化,存在滑模控制量反应不够及时的问题,并且需要预先知道系统不确定性的上界函数,对滑模控制应用到混沌系统控制当中造成了限制.针对变参数的Lorenz混沌系统提出了一种模糊滑模控制方法,控制系统到达平衡状态.模糊控制器的输入为滑模面S,通过设计合理的输入输出隶属度函数以及模糊规则,输出的μ值能在线调节滑模控制切换量中的切换增益,有效地解决了滑模控制量反应不够及时的问题；另外设计了状态观测器,对系统的不确定性函数进行了估计.仿真实验结果验证了所提出的模糊滑模控制有着良好的控制效果.%Traditional sliding mode control method, in which switch gain is obtained by system's uncertainty upper bound functions. Causing a problem that sliding mode control may not respond promptly enough, because the swith gain acquired through this way can not make corresponding changes when states of controlled system does. The other drawback is upper bound of the system indeterminacy function need to be know in advance, that impose restrictions when sliding mode control applied to control chaotic systems. For the Lorenz system with variable parameters, a Fuzzy-Sliding mode control method is proposed for regulating the chaotic system to reach its equilibrium. Furthermore, it is seen that the Input of designed fuzzy controller is sliding mode surface S, while the output is μ which is used to adjust the swith gain on line by reasonable design of fuzzy-sliding mode control rules. In addition, a state observer is proposed to estimate the upper bound of system's uncertainty function. Simulation examples are presented to verify the effectiveness and excellent control effect of the proposed fuzzy-sliding mode control method.