Discrete time variable structure control with fuzzy adaptive regulation of reaching law for building structure

Existing discrete time variable structure control methods for reducing seismological response of building structure, such as those of Cai et al^[9] and Zhao et al^[10], suffer, in our opinion, the shortcoming that it is almost very difficult to avoid excessive chattering effect. Therefore, based on the advantages of discrete time variable structure control and fuzzy control, we propose a new discrete time variable structure control method with fuzzy adaptive regulation of reaching law. Such a method can not only reduce seismological response but also avoid undue chattering effect. In the full paper, we explain in detail the application of the discrete time variable structure control method to the control of seismologically excited structural systems. We give numerical simulations for MDOF (Multiple-Degree-of-Freedom) shear building model containing an active brace system. The results of seismological response are shown in Table 2 and Fig.6; they show that, like Refs.9 and 10, seismological responses can be markedly reduced. The results for chattering effect are given in Figs.3 and 5; Fig.3 is for Refs.9 and 10, and Fig.5 is for the discrete time variable structure control method with fuzzy adaptive regulation of reaching law; Fig.5 shows preliminarily that our method can keep the chattering effect sufficiently low but, in this case, Refs.9 and 10 cannot do so.