基于符号特征和混沌参数的车辆悬架隔振性能综合评价

The comprehensive evaluation for anti-vibration performance of vehicle suspension based on symbolic characteristic and chaos parameter

为了更好地分辨车辆悬架隔振性能,采用符号特征和混沌参数建立了车辆悬架隔振性能评价的新方法.分析了车辆悬架隔振性能评价方法的现状和问题,简述了对时间序列进行符号分析和混沌分析的特征和参数,通过实验获得了具有B J212钢板弹簧式非独立悬架结构的某试验车前悬架当钢板弹簧数量改变时的悬架振动时间序列,对悬架振动时间序列计算获得了悬架系统参数(如一阶固有频率f0和阻尼比ξ)、符号参数(如Shannon熵)及混沌参数(如最小嵌入相空间维数Mm in和关联维D2).结果表明,随着前悬架钢板弹簧数量减少,悬架吸收振动冲击的能力下降,悬架减振能力下降;其一阶固有频率f0下降了14%、阻尼比ξ下降了10%,悬架吸收振动冲击力的最大值下降了13%;"1-Shannon熵"与关联维D2均呈现大-小-大的变化趋势,在4片钢板弹簧时两者均有最小值.基于符号特征"1-Shannon熵"和混沌参数关联维D2共同建立了复合参量F.较之两个初始特征参数,F的变化趋势更为显著,可用于综合评价车辆前悬架钢板弹簧数量改变时的隔振性能.

In order to identify the anti-vibration performance of vehicle suspension （ AVPVS）, a new technique to evaluate the AVPVS is established by the symbolic characteristics and chaos parameters. The progress and problems about the evaluating technique for AVPVS are analyzed; The characteristics and parameters from the analysis of symbol and chaos to a time sequence is briefly depicted;The suspension vibration time sequence from a front suspension of the test automobile, which is with the model BJ212 and with the leaf spring rigid axle suspension, is obtained while changing the amount of leaf spring. The system parameters of suspension such as the first inherent frequency f0 and the damp rate ξ, the chaos parameters such as the minimum embedding symbolic parameters such as Shannon entropy, the dimension Mmin and the correlation dimension D2, are obrained by calculating the suspension vibration time sequence. The results show that with the decrease of leaf spring of front suspension, the suspension capacity to absorb vibration wallop is reduced; the first inherent frequencyfo is decreased by 14% meanwhile the damp rate ξ is decreased by 10%, the maximum value to absorb vibration wallop by suspension is decreased by 13% ; the ＂1-Shannon entropy＂ and Correlation Dimension D2 are both with the variety trend of ＂large-little-large＂, both of which are with the minimum value in the 4 piece of leaf spring. The compound parameter F is established based on the symbolic characteristic ＂1-Shannon entropy＂ and chaos parameter Correlation Dimension D2. Comparing with the two original characteristic or parameter, the variety trend of F is more remarkable, therefore it can be used to evaluate synthetically for the anti-vibration performance of vehicle front suspension while the amount of leaf spring changes .