电动汽车振动信号混沌特性

Experimental Research on Chaotic Analysis of Electric Vehicle Vibration Signal

为研究电动汽车的混沌动力学特性,对某款电动汽车进行了实车试验,并对试验数据进行了混沌动力学特性分析.首先,在铺路面上对电动汽车进行实车试验,测得轮心垂向、减振器上安装点垂向和电池底部中心垂向的振动加速度信号.其次,利用小波分析对信号进行降噪处理,比较了全局阈值降噪和分层阈值降噪的去噪效果,发现分层阈值降噪对信号的处理效果较好.利用降噪后的信号计算得到左前轮心垂向、左前减振器上安装点垂向和电池底部中心垂向信号的庞加莱截面和相图,并利用互信息法计算时间延迟、Cao法计算最小嵌入维,最后利用小数据量法得到最大李雅普诺夫指数.分析结果表明,汽车在铺路面上行驶时存在混沌运动.研究结果的应用,可使电动汽车在设计和分析时,能尽可能地避免系统混沌运动的产生.

In order to research chaotic dynamics of electric vehicles, the vehicle experiment was carried out, and the experimental data were analysed. First, the vehicle experiment in the paving road was carried out, the vertical acceleration signals of wheel center, shock absorber top mount and battery bottom center were measured. Secondly, the noise of signals were reduced by using the wavelet analysis, and compare the effect between global threshold noise reduction and layered threshold noise reduction, then found that the effect of the layered threshold was better. With the de-noised signals, the Poincare sections and phase diagrams of the vertical of left front wheel center, the front left shock absorber top mount and battery bottom center were calculated, and time delay was calculated by using the mutual information method, and also minimum embedding dimension was calculated through the Cao method, the largest Lyapunov exponent was obtained by using the small data sets method. The results show that the presence of chaotic motions in the electric vehicle when traveling on paving road. The results of the study can avoid the generation of chaotic motion in the design and analysis of electric vehicle as much as possible.