Abstract: For lossy compression algorithm, such as SDT, box car, backward slope, it is difficult to find a suitable compression deviation[ΔE]. So compression deviation seriously limits the compression algorithm’s practicability and convenience. In view of this, it puts forward a dynamic parameter control method based on compressed ratio CR（CR=1－number of data compression/number of data before compression）. It assumes that the compression ratio CR and compression deviation have linear relation. Given the compression ratio[CRdest], it can dynamically adjust [ΔE] so as to[CR→CRdest]. The method makes compression ratio under control, and reduces the actual operation difficulty for related compression algorithm.

Key words: Spinning Door Transformation（SDT）, process data, lossy compression, compression deviation, recording limit, compression ratio

摘要： 对于涉及使用压缩偏差[ΔE]的有损压缩算法（如旋转门算法、矩形波串法、后向斜率法），一般需要长时间的实验才能得到合适的[ΔE]。对于测点较多系统简直是一种灾难。因此，[ΔE]的设置严重限制了压缩算法的实用性和方便性。鉴于此，提出了以压缩比CR（CR=1－压缩后的数据个数/压缩前的数据个数）为导向的动态控制方法。它假定压缩比CR和压缩偏差[ΔE]之间存在线性关系。在给定目标压缩比[CRdest]的条件下，借助于先前一段数据压缩情况，在可调区间[ΔEmin,ΔEmax]上动态地调整[ΔE]，使实际[CR→CRdest]。该方法的特点在于使得压缩比可控，同时降低了相关压缩算法参数设置难度。

关键词: 旋转门算法, 过程数据, 有损压缩, 压缩偏差, 记录限, 压缩比