汽车非线性半主动悬架系统时滞反馈控制

Delayed Feedback Control of Vehicle Semi-active Suspension System

研究了两自由度非线性悬架系统垂向振动的时滞反馈控制。以汽车1/4车体和单个轮胎的两自由度垂向振动模型为例进行研究;其中非线性主要考虑了汽车悬架刚度的三次及五次非线性。利用多尺度法获得含时滞反馈控制的非线性半主动悬架、车体与轮胎振幅的近似解析表达式。分析时滞反馈控制对悬架系统振动的影响规律;并与不含时滞反馈控制的被动非线性模型进行比较。研究了当外激励频率等于主系统一阶共振频率;并且存在一比五内共振时,车体振动情况。重点分析时滞反馈控制的两个重要参数:时滞反馈增益系数和时滞量对车体振幅的影响;并进行相应的稳定性分析。以某型轿车参数进行数值分析研究,得出当时滞阻尼系数固定为-100 N·s/m时,车体振幅随时滞呈波浪形变化。时滞量τ取在区间[0.15,0.64]上时,车体振幅小于被动系统车体的振幅,表明时滞对系统具有减振作用;而在其他时滞区间上,车体振幅反而会比被动系统的振幅还要大。同时探讨了如何优化设计时滞阻尼系数并计算出相应的最佳时滞,使得主系统的幅度最小。

The delayed feedback control of vertical vibration is studied in a two degree of freedom vehicle semiactive suspension system. The two degree of freedom vertical vibration model of automobile 1/4 tire is studied as an example. The cubic and quantic nonlinear stiffness of vehicle suspension system are considered in the analysis. The multiple scales method is employed to obtain the approximate analytical solution of the car body and tires amplitude in the vibrating system. The effect of time delay feedback contrl on vibration of the semi-active suspension system is analyzed. The results of semi-active control are compared investigated when the external frequency nears the first mode frequency and vibration of a car body with one to five resonances occurs simultaneously. The focus is to analyze the effect of time delay and gain on amplitude of car body as well as the corresponding stability. The parameters of a certain type of car are analyis concluded that when the damping cofficient of the car is fixed at -100 N·s/m ,the amplitude of the body shows wavy change with time delay. When the time delay1 is between [0.15,0.64] the amplitude of the car body is smaller than that of the passive system, which indicates that time delay has adamping effecon other delay intervals, it’s larger. The amplitude of the car body can be suppressed to a mininum value when time delay is chosen as the optimal value by the method of optimization method.