Lossless Compression Technology In The Posture Data Acquisition System

Acquisition a variety of projectile flight attitude parameters has an important signification no matter for projectile design or projectile aerodynamics. While projectile is in flight, a number of sensors combined are needed to measure flight attitude parameters, so that the output data is quite large. Consequently, lossless data compression used in the system of attitude measurement is important.Considering the characteristic of projectile flight attitude, the measurement system which consists of signal conditioning, data acquiring, data compression and data storing is designed, so that bulky data can be stored after data compression. Firstly, the characteristic of projectile flight attitude is analyzed, and several measurement concept designs are proposed. The design based on DSP is chosen and the theory of the design is presented. Secondly, in order to choose lossless data compression algorithm adapted to the system, several algorithms are introduced and filtered combined with the merit and the disadvantage. Dynamic layout algorithm is selected because of high compress ratio and fast compress rate, and then dynamic layout algorithm is simulated. Thirdly, the design of hardware and software was described. The design of hardware is composed of the chip selection such as the DSP selection,the ADS selection and the memorizer selection, and the design of hardware circuit such as signal conditioning,data acquiring,data storage,power supply and so on. The design of software consisted of the configuration of .CMD and the achievement of lossless data compression algorithm in DSP are given.The system is debugged. Data decompression achieved in MATLAB, original flight attitude signal renewed, and the precision analyzed are contained in the experiment, which proved that the design is satisfied with the system of attitude measurement. Not only memorizer is reduced, but also the cost is saved.