自适应模糊滑模控制在化工过程中的应用

为有效处理多变量、非线性及非最小相位系统的复杂化工过程,提出了一种新型的自适应模糊滑模控制,该方法针对滑模控制鲁棒性好但存在抖振的问题,采用模糊控制柔化控制信号,而与滑模控制的结合可以充分利用系统信息,简化模糊控制;在此基础上提出一种新的自适应调整比例因子来进行模糊变论域,柔化了控制信号并减小了滑模控制器输出的抖振。并给出模糊滑模控制的算法和稳定性分析,得到简化后的通用模糊规则库,可通过比例因子在线调节输入量的论域,使构成的控制系统具有很强的鲁棒性、较好的自适应能力和较高的控制精度。最后对于非线性单输入单输出(SISO)和多输入多输出(MIMO)化工模型进行仿真研究,结果表明即使工况点发生大的变化或受到较大干扰时,仍具有良好的抗扰动能力和很强的鲁棒性。

Adaptive fuzzy sliding mode control in chemical process application

In this paper,a new adaptive fuzzy sliding mode control is used to deal with complex chemical process with multivariable nonlinear and non-minimum phase systems.This method for sliding mode control has good robustness,but existing the chattering problems of controller output.The fuzzy control is used to soften the control signal and simple the fuzzy control,with the combination of sliding mode control can make full use of the system information.By adopting a new adaptive fuzzy factor to adjust proportional variable domain,the control signal is softened and reduces the output chattering of sliding mode controller.Meanwhile,the fuzzy sliding mode control algorithms and stability analysis are given;simplified general fuzzy rule is got.To make the control system has strong robustness,better adaptive ability and high control precision by using the scaling factor to adjust input amount of domain and rules of membership functions on line.Finally,the results of simulation experiment on nonlinear SISO and MIMO chemical models show that even big changes or heavy interference is happened in its operation points;the control system still has good disturbance and strong robustness.