Active vibration control of time-varying mechanical systems based on an adaptive algorithm with model real-time identification

Phenomena of time-varying parameters widely exist in mechanical systems. If a system's parameters change greatly with time, effects of time-varying parameters on control algorithm should be considered in active vibration control schemes. Here, an adaptive algorithm with model real-time identification was proposed for suppressing vibration of time-varying mechanical systems with larger variation of dynamic characteristics. The proposed algorithm combined the traditional filtered adaptive algorithm and the recursive prediction error method, the latter with gradient change was used to estimate the control channel model in real time. A time-domain model for longitudinal vibration of a non-uniform cross-section beam with spring-mass supports was established. The spring stiffness in the model changes with time to cause larger variation of the model's dynamic characteristics. Numerical simulation for vibration control was performed for the established beam model using the proposed adaptive algorithm with model real-time identification. Simulation results showed that the proposed control algorithm can effectively suppress the time-varying system's narrowband and broadband vibration; compared to the existing adaptive algorithms, the proposed algorithm can have a better control performance. Finally, the proposed control algorithm was applied in vibration control tests of a time-varying swing system. It was shown that test results verify the feasibility and effectiveness of the proposed control algorithm. © 2020, Editorial Office of Journal of Vibration and Shock. All right reserved.