柴油机双层隔振非线性系统主动隔振研究

摘要

针对柴油机双层隔振系统，考虑误差通道严重非线性影响动力系统建模、振动分析以及主动控制策略设计、隔振效果，在预补偿模型参考自适应逆控制的线性化算法基础上，集成自适应陷波算法，形成自适应复合控制策略。在柴油机双层隔振系统主动隔振试验中，基于 Hammerstein 型非线性系统解耦及基频广义频响函数分析，建立线性化参考模型及提取误差通道相频特性曲线，分析提出的自适应复合控制策略，结果表明：接近目标非线性系统的线性参考模型，能够获得好的线性化效果和提供精确的误差通道相频特性曲线，并与相频曲线 FIR 模型拟合一起，决定着自适应复合控制策略的隔振效果；而与系统能量建模结果对比表明，只有通过消除系统非线性来抑制其对谐频振动影响，才能获得最优的系统振动能量级隔振效果。%Aiming at diesel two-stage vibration isolation system,considering that the heavy nonlinearity of the secondary path influences its dynamic system modeling,vibration analysis,active control strategy design and its control performance,a hybrid adaptive control strategy was presented here by integrating the adaptive notch filtering algorithm with the pre-compensator model reference adaptive inverse control (PCMRAIC).In an active vibration isolation test of diesel two-stage vibration isolation system,based on decoupling Hammerstein nonlinear system and analyzing generalized frequency response functions (GFRFs),linearized reference models and phase-frequency curves of the secondary path were built,and then the hybrid adaptive control strategy was analyzed.The results showed that the linearized reference model aprroaching the target nonlinear system can be employed to realize the excellent linearization of the system and provide the accurate phase-frequency curves of the secondary path,furthermore,the linearized reference model and the FIR model fitting of phase-frequency curves are adopted to determine the vibration isolation effect of the hybrid adaptive control strategy.In addtion,the results of the active vibration isolation test were compared with those of the vibrational energy modeling.It was shown that the vibration isolation effect of the optimal system vibrational energy level is obtained only when eliminating nonlinarity and suppressing its effect on the harmonic vibration of the system.