Seam Tracking Signal Detection And Processing Based On Position Sensor

With the application of the NG-weld tracking technology, more and more tracking methods are being used, however, the most active and fruit is the study of sensor technology, and the seam tracking technology is gradually walking to the mature stage.On the basis of references and research fruits of home and abroad, this paper designs a signal acquisition and processing system based on contact type sensor, and then tested by the experiment of signal acquisition, the applying range and target of the system also would be concluded at last.Firstly, this paper designs a contact type sensor which acts as the main body of acquisition module from the aspects of mechanical type probe, angle adjusting device,capacitive sensor and signal conversion circuit based on the deep and narrow characteristic of seam, and makes it to be satisfied to narrow gap weld better.Secondly, the signal processing module is constructed by hardware and software and the channel of signal traveling and processing is built. The hardware structure is organized by the PIC18F4520 MCU main control chip and auxiliary circuit which includes amplifier and signal isolation circuit, it would take action by corporation of both; the software structure is performed by the main program which nests each other of subprogram which operates in the environment of MPLAB IDE of MCU, and it can achieve the functions of signal acquisition, signal filtering and signal display orderly.Finally, the performance of contact-type sensor and signal acquisition and processing system is tested by the seam tracking signal acquisition experiment, and drawing the conclusion that the contact-type sensor would be used in which seam and how much deviation and the system should be performed in what speed by analyzing the data and seam deviation signal oscillograph. The differential measurement method is introduced to optimize the non-linearity error of capacitor at last. The seam tracking system is proved that it satisfies the requirement by the experiment results.