基于动态字典和差分编码的计量数据压缩研究

Research on metrology data compression based on dynamic dictionary and differential coding

针对计量自动化系统中大量用电信息给数据传输和存储带来的压力,文中分析了计量自动化上行传输协议的帧结构特点和时序特征,设计了一种基于动态字典和差分编码的数据压缩方案。利用通信帧结构特征,通过差分编码实现数据压缩。针对传统差分编码算法在原始数据波动时压缩率低的问题,引入字典算法进行差分基值管理,通过将帧结构中的固定报文属性信息和高频元素存入字典作为差分基值,在压缩过程中根据数据分布特征对字典进行动态学习,提高算法对不同数据类型的适应性。最后通过电压和电能量数据的压缩实例分析,验证了文中方法的有效性。

In view of the pressure brought by a large amount of power consumption information to data transmission and storage in the measurement automation system,the frame structure and timing chara-cteristics of power consumption information transmission protocol are analyzed,and a data compression scheme based on dynamic dictionary and differential coding is designed.Using the correlation between adjacent data points in time or space,data compression is realized by coding the difference between adjacent elements.In view of the low compression rate of traditional differential coding algorithm for data sources with large data fluctuation,the dictionary algorithm is introduced to manage the differential base value.By storing the fixed message attribute information and high-frequency elements in the frame structure into the dictionary as the differential base value,the dictionary is dynamically learned according to the data characteristics to improve the adaptability of the algorithm to different data types.Finally,the compression case of voltage and electric energy data is analyzed to verify the effectiveness of this method.