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行驶车辆振动信号的小波分析 总被引:10,自引:0,他引:10
本文介绍了小波分析的理论方法,并上小波分析方法应用到了行驶车辆振动的分析中,即:通过二进离散小波变换,把实际振动信号进行多层小波分解,使异常信号和非平稳高频信号得到良好的时间定位和图形显示,并把信号的路面激励与本体振动分离开来。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(6):847-873
Reliability of the railway vehicle suspension system is of critical importance to the safety of the vehicle. It is very desirable to monitor the health condition and the performance degradation of the suspension system online, which offers the important information of the suspension system and is critically important for the condition-based maintenance rather than scheduled maintenance in the future. Advanced fault diagnosis method is one of the most effective means for the health monitoring of the suspension system. In this paper, taking the lateral suspension system as an examcple, the fault isolation issue for different component faults occurring in the suspension system is concerned. The sensor configuration for obtaining the vehicle state information and the mathematical model for the lateral suspension system are presented. Four fault features in the time domain and three fault features in the frequency domain are used for each sensor signal. Three different methods, Dempster–Shafer (D–S) evidence theory, Fisher discrimination analysis (FDA) and support vector machine (SVM) techniques are applied to the fault isolation problem. Simulation study is carried out by means of the professional multi-body simulation tool, SIMPACK. The simulation results show that these methods can isolate the considered component faults effectively with a high accuracy. The D–S evidence-based fault isolation approach outperforms the other two methods. 相似文献
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通过分析发动机振动信号的基频与转速之间的数学关系,设计了基于LabVIEW的采集系统,利用小波变换的方法提取振动信号的基频,提出了一种精度高、易于实现的发动机瞬时转速检测算法,并通过试验验证了该方法的可行性.经过与实际转速比较,该算法的误差率在1%以内,准确性和鲁棒性均符合测量求,具有重要的实用价值. 相似文献
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Vehicle Dynamic Analysis and Evaluation of Continuously Controlled Semi-Active Suspensions Using Hardware-in-the-loop Simulation 总被引:3,自引:0,他引:3
Sung-Ho Hwang Seung-Jin Heo Hong-Seok Kim Kyo-Il Lee 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1997,27(5):423-434
A semi-active suspension system with continuously variable damper is greatly expected to be used mainly in the future as a high-performance suspension system due to its cost-effectiveness, light weight, and low energy consumption. In this paper, to develop a suitable control logic for the semi-active suspension system, the hardware-in-the-loop simulation is performed for the experimental continuously variable damper combined with a quarter-car model, and the simulation results are compared for passive, on/off controlled, and continuously controlled dampers in the aspects of ride comfort and driving safety, assuming each damper to be installed on the vehicle. 相似文献
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基于半主动自适应悬架系统的整车道路友好性研究 总被引:1,自引:0,他引:1
为了提高车辆的道路友好性与平顺性,设计了以磁流变减振器为控制对象的整车自适应模糊控制半主动悬架系统。在试验测试和理论分析的基础上,建立了基于磁流变减振器的整车半主动悬架模型及其状态方程,并用该模型对自适应模糊控制方法进行了研究。模型的输入采用B级和C级路面谱;道路友好性评价指标采用动载荷系数和动载荷应力因子;使用MATLAB/Simulink建立基于2个自适应模块的模糊控制器控制系统,模糊控制器的输入均采用车身与车桥的相对速度和相对加速度。仿真结果表明:与被动悬架相比,在B级和C级路面、不同速度下,半主动自适应悬架动载荷系数均降低30%左右,动载荷应力因子均降低40%以上,同时也提高了车辆的运行平顺性和稳定性。 相似文献
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针对从缸盖振动信号中分离燃烧激励引起的振动信号及其他干扰信号的问题,提出一种基于时‐频相干与神经网络的气缸压力识别方法。首先采用 Morlet 连续小波变换分别将缸盖振动信号和缸压信号在时‐频域内展开,然后采用交叉小波对两信号进行时‐频相干分析,设定相干系数阈值并进行掩膜处理,对所得结果重构便可得到燃烧激励引起的缸盖振动信号。最后,选取8个参数作为评价燃烧效果的特征指标,利用径向基函数(RBF)神经网络估计缸压。研究结果表明:该方法有效地提取了缸盖上的燃烧特征信号,通过 RBF 神经网络估计缸压,逼近于实际缸压变化。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4):297-312
In this paper, a load-leveling suspension system with a magnetorheological (MR) damper is investigated. In this suspension system, the MR damper is connected to a spring to form a load-leveling suspension system. The system effective stiffness and damping can be adjusted by controlling the MR damper. The characteristics of a load-leveling suspension system are studied first. When the linear damper is replaced with an MR damper, the averaging method is adopted to obtain the steady-state response of the nonlinear system. A comparison demonstrates that the results of the averaging method are in good agreement with those obtained by numerical simulations. The analytical results are then verified experimentally. The load-leveling suspension system studied here is able to adjust both suspension stiffness and damping and, hence, it may provide more effective vibration control in a wider frequency range, when the damper is controlled. 相似文献
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Y. Shen M. F. Golnaraghi G. R. Heppler 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2007,45(4):297-312
In this paper, a load-leveling suspension system with a magnetorheological (MR) damper is investigated. In this suspension system, the MR damper is connected to a spring to form a load-leveling suspension system. The system effective stiffness and damping can be adjusted by controlling the MR damper. The characteristics of a load-leveling suspension system are studied first. When the linear damper is replaced with an MR damper, the averaging method is adopted to obtain the steady-state response of the nonlinear system. A comparison demonstrates that the results of the averaging method are in good agreement with those obtained by numerical simulations. The analytical results are then verified experimentally. The load-leveling suspension system studied here is able to adjust both suspension stiffness and damping and, hence, it may provide more effective vibration control in a wider frequency range, when the damper is controlled. 相似文献
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Hongrui Wang Alfredo Núñez Zhigang Liu Yang Song Fuchuan Duan Rolf Dollevoet 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2018,56(8):1207-1232
This paper studies the evolvement of the wear irregularity of contact wire using wire thickness data measured yearly from a section of railway catenary. The power spectral density and time–frequency representation based on the wavelet transform are employed for data analysis, with an emphasis on local wear irregularities that are crucial for contact wire condition assessment. To investigate the cause of wear irregularity evolvement and the mutual influence with the pantograph–catenary dynamic interaction, simulations considering the influence of wear irregularity are carried out based on the finite element method. Analyses of the actual wear irregularities and the dynamic contact force under singular and complex wear irregularities are performed. Although the wear irregularity has limited impact on the pantograph–catenary interaction, it can induce the vibration of pantograph and contact wire that will lead to a notable increase of contact force standard deviation. The evolvement of wear irregularity is closely associated with the span length and dropper distribution of catenary structure and the running direction of pantograph. In addition, it is found feasible to detect the wear irregularity based on contact force, on condition that the sampling frequency is high enough to reflect the indicative frequencies. 相似文献
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以锂电池-超级电容构成的复合电源电动汽车为研究对象,在满足动力性能的前提下,为实现超级电容在合理的荷电状态(SOC)下承担高频率信号,且锂电池承担低频率信号的目标,建立了实时小波变换-模糊控制的能量管理控制策略。基于Matlab/Simulink和ADVISOR软件搭建整车模型,并在NEDC循环工况下进行仿真测试。仿真结果表明,与单一锂电池相比,在小波变换-模糊控制策略下,复合电源锂电池的驱动峰值电流降低了20.68%,寿命提高了16.74%。搭建了按一定比例缩小的复合电源系统试验平台,并在NEDC工况下进行试验验证。结果表明,小波变换-模糊控制策略对复合电源电动汽车的能量管理具有良好的控制效果。 相似文献
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斜拉桥拉索减振阻尼器对拉索索力测量的影响研究 总被引:1,自引:1,他引:0
针对采用频率法测量拉索索力时拉索外加阻尼器对索力测量精度影响的问题,提出了考虑拉索垂度的拉索-阻尼器系统模态频率的分析方法,研究了阻尼器安装的相对高度、拉索的计算长度、阻尼系数等对拉索模态频率的影响程度和规律,获得了消除拉索减振阻尼器对索力测量精度影响的办法。研究表明,外加阻尼器对拉索低阶模态频率影响很大,采用高阶模态频率测量拉索索力时,索力测量能获得很好的精度。随着拉索-阻尼器系统相对安装长度和阻尼系数的增大,阻尼器对拉索模态频率的影响也越大,当阻尼系数增加到一定程度后,拉索的高阶模态频率基本与阻尼系数无穷大时的频率接近,阻尼器相当于固定支撑。以岳阳洞庭湖大桥A11号拉索为例,验证了该方法合理可行。 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(7):1025-1041
In this paper, a magneto-rheological (MR) damper-based semi-active controller for vehicle suspension is developed. This system consists of a linear quadratic Gauss (LQG) controller as the system controller and an adaptive neuro-fuzzy inference system (ANFIS) inverse model as the damper controller. First, a modified Bouc–Wen model is proposed to characterise the forward dynamic characteristics of the MR damper based on the experimental data. Then, an inverse MR damper model is built using ANFIS technique to determine the input current so as to gain the desired damping force. Finally, a quarter-car suspension model together with the MR damper is set up, and a semi-active controller composed of the LQG controller and the ANFIS inverse model is designed. Simulation results demonstrate that the desired force can be accurately tracked using the ANFIS technique and the semi-active controller can achieve competitive performance as that of active suspension. 相似文献
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Semi-active Damping with an Electromagnetic Force Generator 总被引:1,自引:0,他引:1
D. Ryba 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1993,22(2):79-95
The main shortcoming of vehicle suspension systems is the amplification of input vibrations at the resonant frequency. A non-amplifying suspension system with a semi-active damping is being developed. The use of an electronically controlled rotational damper has been studied theoretically. A new sprung seat is being designed for the improvement of the working conditions for drivers of road and terrain vehicles. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(4):279-308
Summary This paper deals with single-wheel suspension car model. We aim to prove the benefits of controlled semi-active suspensions compared to passive ones. The contribution relies on H 8 control design to improve comfort and road holding of the car under industrial specifications, and on control validation through simulation on an exact nonlinear model of the suspension. Note that we define semi-active suspensions as control systems incorporating a parallel spring and an electronically controlled damper. However, the type of damper used in automotive industry can only dissipate energy. No additional force can be generated using external energy. The control issue is then to change, in an accurate way, the damping (friction) coefficient in real-time. This is what we call semi-active suspension. For this purpose, two control methodologies, H 8 and Skyhook control approaches, are developed, using a linear model of the suspension, and compared in terms of performances using industrial specifications. The performance analysis is done using the control-oriented linear model first, and then using an exact nonlinear model of the suspension incorporating the nonlinear characteristics of the suspension spring and damper. 相似文献