Control Software Improvement And Optimization Design Of Energy Spectrum Acquisition Circuit For Density LWD Tool

Density Logging While Drilling(LWD)is a logging method in which the radioactive source generates gamma rays and reacts with the rock stratum to generate signals to determine the characteristics of the rock stratum.The density LWD tool is based on the principle of density logging while drilling and is a logging tool that measures the density of the formation and the photoelectric absorption cross-section index through the Compton effect that occurs when the gamma rays pass through the formation.Based on the measurement principle and structural composition of the density LWD tool,this thesis analyzes and obtains various performance indicators required for the measurement and operation of the instrument and summarized the defects and flaws of the current density LWD tool,namely: 1)The energy spectrum acquisition module still has temperature drifts after using the full energy peak at 0.662 Me V in the energy spectrum for overall gain control.2)The main control software circuit of the density LWD tool takes too long for a single acquisition cycle during operation and cannot respond to commands in real time during data acquisition time.Aiming at the phenomenon of electric temperature drift in energy spectrum acquisition,the thesis starts from the structure of energy spectrum acquisition circuit,analyzes the characteristics of photomultiplier tube,preamplifier circuit and peak hold circuit,discuss and research the optimization scheme of peak hold circuit and preamplifier circuit.Determined the optimal scheme of the energy spectrum acquisition circuit of the density logging while drilling tool by Discussing Performance differences of Gaussian signal shaping circuits in preamplifier circuits under different parameters.For the multi-task optimization requirements of the main control software,the thesis optimized the main control software,and a main control software for density LWD based on the ?C/OS-II real-time operating system is designed.The control software uses multi-task parallel design logic,including command analyzing and processing tasks,command sending task,working process tasks,and state control tasks.Through the reasonable distribution of task functions,the software control logic is optimized,which reduces the time-consuming of communication and processing in a single sampling cycle and improves the overall performance.operating efficiency.Finally,a simulation experiment is carried out on the design in this thesis,which verified that the performance of the optimized design of the energy spectrum acquisition circuit of the density LWD tool meets the design requirements.Through a series of tests,the main functions and running time parameters of the main control software of the LWD density logging tool are verified.The simulation and experiment results show that the performance of the improved energy spectrum acquisition circuit and the main control software are optimized,which can meet the accuracy requirements of field exploration.