Research on an Active Vibration Isolation System with Hybrid Control Strategy for The Guidance System of TBM

PurposeThe full-face rock tunnel boring machines (TBM) generate intensive vibration while cutting rocks, which will lead to poor accuracy of the guidance system. Therefore, it is necessary to design an active isolation system to attenuate the vibration transmitted to the guidance system.MethodsThis paper presents a single-degree-of-freedom active isolation system driven by a voice coil motor for the guidance system of TBM to work well in an intensive vibration environment. A hybrid control strategy based on feedforward control and feedback control is proposed according to the state equation of the active isolation system. Objective function based on the mounting plate acceleration is established for the linear quadratic regulator (LQR) controller. The weighting coefficients of the LQR controller are optimized by a genetic algorithm for better vibration control performance.ResultsSimulations and experiments based on the proposed hybrid control strategy are carried out at excitation frequencies of 5, 8, 12, 15, 17, and 20 Hz, respectively. The results show that the designed electromagnetic active vibration isolation system has a displacement attenuation less than -17 dB and an acceleration attenuation less than -21 dB.ConclusionsThe acceleration transmitted to the mounting plate under the action of the proposed active isolation system is less than 0.2 g, which meets the vibration requirements of the guidance system of TBM.