The Research Of Test-bench System For Borehole Azimuthal Acoustic Reflection Imaging Logging Tool Based On Embedded Technology

The Borehole Azimuthal Acoustic Reflection Imaging Logging Tool(BARI)is a new generation of imaging logging tool which is able to investigate stratums in a relatively longer distance from the borehole.During the design of the tool,active sondes are introduced and put into use for the first time.Developed with a structure of modularized sondes,the tool is extremely complex with nearly a hundred of acoustic transducers,and multiple sealed electronic cabins which are able to withstand high pressure.Therefore,the calibration and testing of the tool is so difficult that only with dedicated and specially designed system can be achieved.Against this background,a Test-bench system is introduced in this paper.With the help of this system,automatic testing and supplementary calibration of the BARI can be efficiently done.The Test-bench system hardware mainly consists of a Personal Computer(PC),an embedded controlling board,a telemetry simulation board,a bus interface board,a data acquisition board,a relay board and power supply circuits.Drawing on the experience of network interconnection,the Test-bench system is designed with a Master/Slave architecture where the PC acts as the master system while the other components lay around the embedded controlling board make up the slave system.The main boards of the slave system are interconnected with each other via the IO bus extended from the embedded controlling board.These boards pile up in the way of building blocks,thus constructing in the physical space a self-stacking structure.The PC is mainly used for Human Machine Interface(HMI),data processing,data storing and network interconnecting with the embedded controlling board.The embedded controlling board utilizes the ARM7 TDMI chip series S3C44B0 X as the kernel of control and communicates with PC via Ethernet interface.The main functions realized by the embedded controlling board are control of each testing board,data acquisition and the network interface,etc.The other functional boards all utilize programmable devices as the kernel of control.Among them,the telemetry simulation board is designed based on the chip of EP1C12Q240 and integrated with CAN and DTB bus interface.The bus interface board and data acquisition board are designed based on the chip of EP2C20Q240C8.The bus interface board is mainly used to provide bus interfaces for the internal modules of downhole acoustic logging tool.The data acquisition board is used to acquire analog signals and it supports Analog to Digital Conversion(ADC)in up to 16 channels.The software running on PC is developed based on VC++ and takes advantage of the techniques of multithreading,Dynamic Linking Library(DLL)and Multiple Document Interface(MDI).The embedded controlling board software is developed based on the operating system of uClinux with a hierarchical architecture.The other functional board software are all developed using Very-High-Speed Integrated Circuit Hardware Description Language(VHDL),for each functional test,the software module is made up of some sub-modules which are debugged separately and integrated in the top hierarchy of schematic.Based on the idea of hierarchical design and modular programming,the designed software system is highly reliable and extensible.With the help of the software system,testing of the whole tool and the tool sub system is successfully achieved.The Test-bench system for BARI introduced in this paper can facilitate the test of the whole tool or each tool sub.With the help of the Test-bench system,even a non-professional person could know about the working condition of the whole tool or each tool sub.Therefore,it is evident that the Test-bench system has laid foundations for the industrial production of BARI as well as the quick diagnosis of it at logging site.