Author(s): WANG Hai-qun~1, LUO Xiong-lin~1, HUO Zheng-qing~1, XU Ya-lan~1, ZHANG Ying~2
Pages: 12-15+21
Year: 2009 Issue:  S1
Journal: Control Engineering of China
Keyword:  sliding mode variable structure control; chattering; change rate model; polypropylene CSTR;
Abstract: Sliding mode variable structure control has the feature of quick response,insensitive to parameters and external disturbance.However,most methods including the typical reaching law approach need mathematical model,so its engineering application is limited.A sliding mode control based on change rate model is proposed.System deviation and change rate of deviation are chosen as state variables to design switching function.Equivalent control action is designed based on the model,and variable switching control action is designed based on the switching function and system characteristic.Some improvements are made to alleviate the chattering.This control strategy is easy to be realized in engineering with no need of strict mathematical model.Through empirical method,the temperature change rate model of polypropylene CSTR is presented,and based on the model variable structure control scheme is presented. The control scheme has high performance,which demonstrates the validity and usefulness of the proposed method.