Research On Sensor Test Control System Of LWD Ultrasonic Imaging Tool

To detect borehole conditions,ultrasonic imaging while drilling logs uses echo arrival times and echo amplitudes to image the borehole wall,thereby reflecting the geometry and acoustic characteristics of the borehole wall.In the process of developing ultrasonic imaging logging while drilling tools,the sensor is the most basic working unit of the tool,so it is particularly important to test the sensors of the ultrasonic imaging logging while drilling tool quickly and effectively.According to the basic characteristics of ultrasonic imaging logging while drilling,a sensor test and control system of ultrasonic imaging logging tool while drilling is developed.The hardware part of the system includes a motion control circuit based on STM32 and FPGA,and a drive circuit based on DSP;The software part of the system includes DLL,host computer control software and embedded software.The motion control circuit uses STM32 as the main processor to complete the communication and control logic with the host computer;FPGA as the coprocessor to complete the motion control algorithm.The drive circuit uses DSP as the core processor to complete the drive of the stepping motor.The DLL is responsible for issuing motion control commands;the host computer software is developed based on Lab Windows software,and the motion control of the test control system is realized by calling the interface of DLL.Through the actual sensor experiment,the sensor test control system of the ultrasonic imaging logging tool while drilling can successfully complete the motion control of the sensor,and can work synchronously with the acquisition system.The system also has high stability and small error,which provides a strong guarantee for the research and development of ultrasonic logging while drilling tools.