Vibration control of piezoelectric integrated thin-walled structures using disturbance rejection control with double integral model

Aiming at vibration control of piezoelectric smart structures excited by disturbances with frequencies unknown or varying randomly, a disturbance rejection control with double integral model is proposed and developed in this paper. Firstly a double integral state space model of the system is built, and in the meantime, part of system state variables and physical disturbances including external forces, system nonlinearities, modelling errors were summarized as generalized disturbances. Secondly the system is easily decoupled as a result of the advantage of the specific double integral structure, then a proportional integral (PI) observer and a disturbance rejection controller both with fast converging speed are designed. Generalized disturbances are observed accurately and rapidly by the PI observer and fed back to the system through the disturbance rejection controller to control vibrations. Lastly the disturbance rejection control with double integral model is validated through simulations of vibration control of cantilevered smart beam with collocated piezoelectric actuator and sensor. Furthermore, disturbance rejection control with GPI observer is also implemented in the simulations and comparisons are made between the two controllers. The results illustrate that the disturbance rejection control with double integral model is able to effectively control vibrations caused by disturbances with frequencies unknown or varying randomly, and the vibration control performance of it is better than that of the disturbance rejection control with GPI observer. © 2017, Editorial Board of Journal of Northwestern Polytechnical University. All right reserved.