Research On The Universal Hardware System Of Test-bench For Logging Tool Based On The Embedded Technology

The structure of new acoustic logging tool becomes more complex and it has more comprehensive functions to solve more geological problems.The logging environment of high temperature and high pressure requires better stability and reliability for acoustic logging tool.Meanwhile,scientific and timely maintenance is very necessary in the promotion and application of logging tool.Therefore,specialized equipment,as well as scientific debugging strategy,is needed during the process of tool assembly and maintenance to ensure the quality in every production link and quick location of the fault.A test-bench based on the embedded technology for acoustic logging tool is designed in this paper,which using a combination of qualitative and quantitative detection method.It can provide debugging and diagnosis service in different levels for the acoustic logging tool,which could lead to significant improvement in the scientific,hierarchical debugging and field maintenance.This test-bench is helpful to improve the work efficiency and quality,and promote the upgrading of logging tool.Firstly,the borehole azimuthal acoustic reflection logging tool and acoustic logging while drilling tool are taken as examples to analyze the similarities and differences of tool structure,working principle and system connections among the different acoustic logging tools in this paper.Based on the analysis,debugging contents are refined in the four levels of system,section,circuit board and component.Thus,the common and dedicated functional modules which are needed in the universal hardware system of test-bench are listed.Then,this paper presents a master-slave system architecture based on the ARM7 microprocessor and embedded ?Clinux system for the test-bench.Functional module circuits which have FPGA as their controller are designed and added to the extended I/O bus of ARM.The CAN bus module uses SJA1000 controller to achieve a data transceiver with adjustable baud rate.RS485 bus module is designed to act as a serialdata transceiver with a rate of 6Mbps by adopting the thought of state-machine.The SSB bus module achieves a 10 Mbps synchronous serial communication and provides a master or slave node when testing the internal SSB bus of tool.The analog signal generator module is based on DDS technology and generates sine wave signal with adjustable frequency and amplitude.By using the idea of multi-channel selection and programmable gain,the signal acquisition module realizes a 16-channel signal acquisition.The power conversion and management module provides the method of how 220 V AC power converts to low voltage power and high voltage power as well as their detection and output control.The transducer excitation module can test transducers working at the mode of phase-controlled excitation.The flash memory test module includes a reliable memory management strategy,a hardware design and experimental scheme for flash memory test at high temperature,and a quick data reading way based on the FDRB bus.Debugging interfaces with various applications at different levels are formed after classifying and combining the functional circuit boards and signal lines.The normal circuit boards of the downhole tool are used to test these interfaces.Finally,the application method of this test-bench is introduced by conducting the tool tests of the whole work,electronic circuit in the receiving section,consistency of the analog channel boards and high temperature characteristics of flash memory.Besides,by taking the fault diagnosis of +6V analog power in the borehole azimuthal acoustic reflection logging tool as example,the procedure of how to do scientific fault diagnosis using this test-bench is presented.