摘要
根据铁路机车信号设备自身的信号译码需求,提出一种基于正交小波包技术的轨道电路信号的快速压缩方法,以改善目前机车信号记录器直接存储方式给波形数据存储造成的局限性。该方法利用截频性能出色的dmey小波的正交镜像小波滤波器组对机车信号记录器的记录波形信号进行3级小波包分解,按照记录信号制式的不同,在考虑dmey小波滤波器截频特性的前提下,根据小波包分解后的信号频带对应关系,只保留当前轨道电路信号所在频带的波形数据,以达到信号压缩的目的。实验表明,该方法可以对目前铁路现场主要使用的国产移频信号、UM71信号和ZPW-2000信号进行有效压缩和精确重构,且具有算法简单和方案灵活等特点,能够满足铁路现场实际运用的需要。
Based on the wavelet package analysis technique, according to the decoding requirements of railway cab signaling devices, a fast compression method for railway track circuit signals based on the orthogonal wave- let package technique is proposed to overcome the limitation caused by storing of the original waveform data in the cab signal recorder. This method utilizes the mirror dmey wavelet filter group with excellent cutoff frequen- cy performance to carry out three-level wavelet decomposition on the waveform recorded by the cab signaling recorder. Due to the different characteristics of the recorded track circuit signals, with consideration of the cutoff frequency characteristic of the dmey wavelet filter, according to the corresponding relationship between the wavelet decomposition results and signal frequency band, only the data within the frequency band of the track circuit signals are reserved, thus reaching the purpose of signal compression. Experiment results show that this method can be used for effective compression and precise reconstruction of the domestic frequency shift signal, UM71 signal and ZPW-2000 signal, being characteristic of simple computation, flexible-scheme compression and good adaptability to practical requirements of railway sites.
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2009年第6期102-106,共5页
Journal of the China Railway Society
基金
国家自然科学基金重点项目(60736047)
国家高技术研究发展计划(863计划)(2007AA11Z214)
关键词
正交小波包
正交镜像滤波器
机车信号记录器
数据压缩
orthogonal wavelet package
orthogonal mirror filter
cab signaling recorder
data compression
