Embedded Development And Realization Of Acoustic Logging Data Compression Algorithm

Logging is a kind of important method,it can evaluate reservoir in the process of oil exploration and development, and acoustic logging is a current technology. The acoustic logging will produce a large amount of data, when the required data rate is too high to achieve real-time transmission, it can use the data storage instrument to store the data. In order to reduce the storage pressure instrument, the data need to be compressed. Therefore, this paper designed a kind of acoustic logging data compression algorithm, which was based on LempelZiv-Welch(LZW), and completed embedded development and implementation..First of all, through the advantages and disadvantages of various data compression algorithms were compared and analyzed, and according to the demand of the actual requirements of the system, as the core algorithm, LZW algorithm was selected. LZW algorithm used the fixed code length compression coding method and limited storage capacity of the dictionary. For this shortcomings, LZW algorithm was improved. In order to improve the compression efficiency, in this paper, a new compression algorithm was proposed, which Median Edge Detector(MED) model and LZW were combined. MED model predicting the original sound waves data was used, and the prediction error was used as the object of data compression, then the improved LZW algorithm was used to compress the data, it can improve the compression efficiency.Secondly, according to the process of the embedded system development and basing on the analysis of system requirements, the composition of the hardware system and operating system were determined, OK6410 microprocessor was chosen as the system processing core and Linux was chosen as the development of embedded operating system. On this basis the general design of hardware and software system were determined, then the introducing of the key technology in data compression, the process of data transmission need to be solved.Finally the development board and computer were connected to test and evaluate the whole system.The experimental test results show that the designed of acoustic logging data compressionsystem has realized the functions of the acoustic logging data compression, data storage, data transmission and data decompression. Proposed combining the MED forecast model and LZW compression algorithm can greatly improve the efficiency of compression, and can recover data without distortion, it has achieved the desired effects. This will have high application value for the data compression and transmission in acoustic logging.