【作者】 刘传波；

【导师】 莫易敏；

【作者基本信息】 武汉理工大学 ， 机械设计及理论， 2009， 博士

【摘要】 随着全国铁路建设的不断发展,除了高速性与高安全性要求,高舒适性也成为考虑列车运行质量的一个重要指标,列车操纵是否平稳直接影响着列车运行的安全和旅客乘坐的舒适感。目前国内外对列车冲动的评定主要是从车体平稳性和乘坐舒适性两个角度考虑,考虑的因素主要为加速度与其频率特性,重点分析的是横向与垂向冲动,且无统一的冲动评价标准。在冲动的检测手段上,国内机务段多采用木棒倾倒法,依不同横截面的木棒倒下的情况来判断冲动的等级,该方法存在众多的缺陷。据此,本文研究了纵向冲动的机理和检测方法,旨在为旅客列车的舒适性指标提供理论和技术支持,主要研究内容和创新性成果包括:1.纵向冲动判断准则的研究。旅客列车在运行时会受到多种力的作用,其纵向作用力始终处于动态变化的状态,当这种变化较为巨烈时就会引起纵向冲动。纵向力作用在人体上的冲量将会导致人与车体间相对位置的变化,产生较大的晃动,引发人体的不舒适感。而由于人体的敏感度各异,对振动舒适度的判断亦会不同。所以文中进行了列车的纵向动力学分析以及人体敏感度分析,在对采样数据进行了分析、归纳的基础上提出了以纵向加速度的幅值、频率和作用时间为依据的新的纵向冲动判断准则。实验表明,与传统舒适度标准相比,运用该准则进行人体的纵向舒适度判断更为合理与准确。2.纵向冲动信号检测技术的研究。针对列车加速度信号的采集,文中采用嵌入式技术和虚拟仪器技术,设计了以嵌入式工控机为核心,由加速度传感器、调理电路、数据采集卡、CF存储器以及触摸屏和液晶显示器等元器件组成的便携式冲动检测仪。实现了对数据采集、处理、存储与显示的智能控制,现场应用表明其各项设计功能和性能指标符合要求,抗干扰能力强,检测精度高。3.纵向冲动信号分析与处理方法的研究。在采集数据过程中,除去噪声干扰外,还有其它一些无法避免的因素影响冲动采样值,所采样信号主要由加速度信号、背景噪声、振动信号等叠加而成。文中运用数字信号处理技术和虚拟仪器技术,对采样信号进行了物理量解释,动态特性提取,数字滤波和时域频域分析。并提出以信号的自相关函数为基准的纵向冲动信号提取方法,将纵向冲动信号与振动信号成功地进行了剥离,提高了纵向冲动判断的准确性。4.纵向冲动判断方法的研究。依据纵向冲动判断的三要素,文中对纵向加速度信号进行了能量分析,并提出了一套完整的纵向冲动判断方法:以纵向加速度信号为分析对象,通过信号的频率分析判断其低频特性,通过自相关分析剥离振动信号,通过能量分析判断纵向冲动的发生。更多还原

【Abstract】 With the constant development of the national railway system construction, besides high speed and high safety, high comfort is also of vital importance to improve trains riding quality. Whether trains could be manipulated steadily has a direct influence on running safety and passenger’s comfortableness. The currently domestic and international researches focus on ride performance and comfort when assessing impulse grade, which. analyse mainly the transverse and vertical impulse by the amplitude and frequency characteristic of acceleration. And there isn’t a uniform impulse assessing standard around the world yet. The stick-fallen method is being universally applied to measure impact by inland locomotive depots currently. However, there are a lot of disadvantages using this method which evaluates the impulse grade according to the sticks fallen that have different cross section. Hereby, the longitudinal impulse’s criterion and measurement were researched in this paper to provide the theory and technique support for passenger train’s comfort standard. The research task and innovation ideas included the following several respect mainly:1. The research about the norm of judging longitudinal impulse. Passenger trains’ longitudinal force is always dynamic under a variety of force when running. The longitudinal impulse would be caused when the force changed vigorously, and the relative position between passengers with compartment would be changed. Under this changed status, people would be uncomfortable, but this comfortless would be different because of different sensitivity of human bodies. A new judge rule composed of the amplitude, inherent frequency and effect period of longitudinal acceleration was provided in this paper, based on studying the longitudinal dynamics of trains and human sensitivity. And general pattern of longitudinal impulse was concluded through analyzing the acceleration samples. Compared with traditional rules, the new criterion was more rational and exact, which was proved by experiments.2. The study about measuring longitudinal impact signals. Based on the technology of embedded system and virtual instrument, a new portable instrument of impulse testing was developed in this paper to sample trains’ acceleration, which comprises accelerometer, conditioning circuit, data acquisition device, compact flash, touch screen and LCD monitor, and with embedded industrial computer as its kernel. This portable instrument can perform many sampling functions intelligently including acquisition, process, store and display. It was verified by experimentations that the detector achieved the functions and performance goal with high accuracy and high anti-jamming quality.3. The study about anaylsis and process methods of longitudinal impulse signal. Besides noise, there are other inevitable elements interfere the sample during the data acquisition. The sampled accelerator are mainly composed of impact accelerator signal、background noise and vibration accelerator signal. In this paper, sample signals are processed in the respect of translated physical meaning, dynamic feature decimation, digital filte, time domain and frequency domain analysis by digital signal processing and virtual instruments. A new method of extracting the longitudinal impulse signal based on the autocorrelation function was put forward. The longitudinal impulse signal was successfully stripped from vibration signal by autocorrelation analysis, and the judge accurateness of longitudinal was improved.4. The research about methods to determine longitudinal impulse. According to the three key elements, the longitudinal acceleration signal was carried out energy analysis. A complete set of methods to determine longitudinal impulse was put forward, which includes using longitudinal acceleration signal as the object for analysis, using Frequency signal analysis to determine its low-frequency characteristics, using autocorrelation analysis to detach vibration signals, and using energy analysis to determine the occurrence of longitudinal impulse.更多还原