Process Data Copression Method Based On Beidou's Short-message Communication

Beidou's short-message communication,which is a special feature of Beidou satellite navigation and positioning system,is especially used in the situation where the general public communication is not reached.However,because of the limit in frequency of communication and the length of data message,the efficiency of Beidou's short-message is not very high.In order to solve this,a special compression method based on Beidou's short-message was presented.This compression method includes two steps.The first step is called lossy compression.In this step,Spinning Door Transformation(SDT),a kind of common compression algorithm in database field,is as a basic algorithm of it.In addition,a revised BP Neural network PID controller was designed to adjust some parameters used in SDT.The second step is called lossless compression.A method called front-extra-byte and difference-value lossless compression was presented in this step.After a series of experiments,it can be concluded that the original industrial data has compressed successfully and effectively.Meanwhile,variable precision of compression could be available during the compression.Therefore,this compression method has practical value on Beidou's short-message communication,especially considering about the limit in its frequency and packet's length.This paper is mainly as follows:Firstly,some common compression methods and basic principals have been studied.Compression technology usually includes two different types,lossy compression and lossless compression.Considering this paper mainly aiming at industry process data,some special lossy compression methods in industry process field and common lossless compression methods have been focused on in this paper.Secondly,for solving the practice problems mentioned early,a new industry process lossy compression method based on Beidou's short-message has been presented.Before presenting this,PID and ANN(Artificial Neural Network)algorithms had been introduced,and the controlled object model had been designed.In addition,a BP-PID controller was revised and modified successfully.Then,a kind of lossless compression method for industry process data was presented.For creating better compression method with characteristics of data,a new classificationmethod for the industry process data was showed in this part of paper.After this,another compression method for state data and quality tag data was showed as well.Last but not the least thing is that a novel compress method based on Beidou's short-message for industry data saved as float type was presented,since this type of data is the most important type in industry process field.Finally,simulation experiment was conducted for all the algorithms which have been presented.According to results,the best algorithms respectively for float data and quality tag data have been defined.In addition,the algorithm designed for compressing float-type data in this paper has been valued by the experiment which includes two different steps.