Magnetic Sensor Arrays Based On Weak Magnetic Targeting Research

Wireless capsule endoscope technology to the development of internalbody gastrointestinal tract and other organs examined brought tremendousbreakthrough, the wireless location technology is the key technology of thisdiagnostic method, the human digestive tract wireless tracking technology,Commonly used ways of localization in this kind of technology consist ofmedical imaging localization, electromagnetic orientation, RF signalorientation, ultrasonic positioning, and magnetic markers location, etc.However, these wireless localization ways all have this or that kind of faults.In terms of this, considering the continuously in recent years the developmentof magnetic sensing monitoring technology, we can choose the magneticpositioning technology to track the capsule. Based on this idea, I designedmagnetic sensor array measuring system, and used it to detect and locatecapsule endoscope with permanent magnet.The system design process is asfollows:first of all, the permanent magnet basic magnetic field theory arediscussed. the most basic magnetic dipole theory are introduced, followed bythe introduction of the classic magnetic positioning theory. Lastly, theoreticalformula in the several typical shapes of the magnetic field distribution arecarried out, and at the same time, the diagram of magnetic field surroundingthe magnet is simulated out in the MATLAB environment. laying a theoreticalbasis for the system design.began to design the magnetic measurement system hardware, themagnetic structure of the system hardware is builded up by the hardwareequipment selection, introduction, connection step and step. the hardware partof the magnetic system is divided into the measuring magnetic sensor moduleand background data transmission and processing module. In the system,Honeywell’s HMC5883L is selected as sensor; Prechin’s HC6800SCM development instrument is selected as SCM board. Considering the addressdecoding problem between the sensor module and background data transfer, aswitch circuit with a decoder have been designed. decode circuit will choose74LS154decoder; switch circuit choose MAX4501switch, the display uses1602LCD.Design of the software in this magnetic system has been achieved in themanner of division first and total later. Software system, including the mainprogram, initial program, the whole test, interrupt function, the test,calibration procedures, setup, measurement procedures, setting, measurementfunction.two sets of measurement test are carried out by Using this system tothree kinds of typical shape of the permanent magnets. the purpose of the firstset of experiments is to discuss how the distance between the permanentmagnet and the magnetic sensor array influence the positioning accuracy.Second groups of test is to discuss how the sensor spacing in the magneticsensor array influence the positioning precision. Finally carries out statisticalanalysis on test data. we can get some Useful conclusions,including by theeffective distance of the magnetic sensor array, how the array transducerspacing influence the positioning accuracy, how the shape of the permanentmagnet influence the positioning accuracy and some one other...