Vibration Suppressing Of Delayed Feedback Control In Torsional Vibration System

In fact, time delay is an item in the dynamical governing equations according tothe relative theory. The delayed feedback is employed to suppress the harmfulvibration of the target system. The delayed feedback can be used to suppress thevibration of the primary system effectively in the region of the resonance. In the linearvibration system, the vibration of the primary system can be suppressed absolutelywhen the external excitation is harmonic. The control system is easy to design byusing program, the delayed feedback is embedded in the control system to suppressthe vibration. In this paper, the delayed feedback is applied to suppress the vibrationof the torsional vibration system. The focus of this paper is to analyze the effect of thegain and time delay on vibration suppression.First, a linear delayed dynamical vibration absorber is used to suppress thevibration of the primary system in the torsional vibration system. The stability switchmethod is used to analyze the stability of the delayed feedback vibration system. Thestable region of time delay is obtained. The vibration of the primary system can beeliminated absolutely when the gain and time delay are appropriate chosen. Thevibration of the primary system can be suppressed partly at some values of time delay.However, the vibration of the primary system may be increased at some values oftime delay, even the system may be damaged because of instability of the system.Second, a two-degree-of-freedom torsional vibration system is investigated. Thephysical parameters of the passive dynamical vibration absorber control system areoptimized by the theory of antiresonance point. The performance of passive vibrationsuppression is good by optimized design. Third, the delayed feedback is used tosuppress the vibration of the primary system based on the passive control. The methodof stability switch and direct method are applied to analyze the stability of delayedfeedback control torsional vibration system. The genetic algorithm is used to optimizethe control parameters of gain and time delay. The good performance of vibrationsuppression is obtained in wide bandwith of excitation frequency by optimizationdesign. The performance of vibration suppression for delayed feedback control is better than passive control in the vicinity of antiresonance point. Forth, a nonlineardelayed dynamical vibration absorber is used to suppress the vibration of the primarysystem in the torsional vibration system. The method of multiple scales is employedto obtain the approximate analytical solutions of the system. The effects of the gainand time delay on vibtration suppression are analyzed. The results show that for afixed value of the gain, the vibration of the primary system can be suppressed at somevalues of time delay. There is an optimal value of time delay, the vibration of theprimary system can be suppressed maximumly. The best performance of vibrationsuppression could be obtained at appropriate values of the gain and time delay.The results of this paper can provide a new method of vibration suppression fortorsional vibration system. The contribution of this paper is to provide the theoreticalguarantee for the application of delayed feedback control technique in torsionalvibration system.