Research On Control System Of X-ray Detection Machine For Gun Barrels

X-ray detection technique is one of the nondestructive detection technique, and its principle is that detecting the work-piece on the premise of being not to damage the work-piece, and then draw a conclusion that the work-piece is defective or not. Necessarily, we have to find the shape, the position and the size of the defects. In the industrial production, the nondestructive testing technique is used in the raw materials, the parts and the weld of much important mechanical equipment. Nowadays, the nondestructive testing technique is wildly used in more and more fields such as aviation, aerospace, weapon, chemical industry, metallurgy, ship, trail, nuclear industry and so on.X-ray detection machine for gun barrels is made of ray source system, detector system, mechanical motion system, data acquisition system, control system, computer and image processing system, etc. According to the requirement of batch inspection for gun barrels, the paper designed the special fixture,the worktable and the whole control scheme of the x-ray detection machine for gun barrels, considering the safety of the detection, the whole control system includes the main control room, the control room in field and the main control panel ,etc. On the basis of the research above, the system realized on-line detection for gun barrels, achieved the goal that detecting the defects quickly and safely, furthermore, the detection results can guide the production process.For the x-ray detection machine, the scanning motion control is the most important, the accuracy, the stability and the rapidity had effect on the imaging quality. The control mode of upper and lower computer was used in this paper, the industrial control computer was responsible for the whole system control, the human-computer interaction and the image processing, the multi-axis motion control board was responsible for the movement of all axis. It received the instruction from the industrial control computer, and then transferred the order to all servo drivers to control the corresponding servomotors. The multi-axis motion control board received the feedback signal from the photoelectric encoder and the grating ruler and formed closed loop control to ensure that the system was high precision.The basic requirements for the motion control system were the accuracy, the stability and the rapidity. To realize these requirements, it is necessary to establish the open loop transfer functions and the closed loop transfer functions had according to the relative servomotor parameters. From the bode-diagram, the phase margin and the amplitude margin was analyzed, and the series correction, the parallel correction or PI correction were added in the transfer functions to change the system performance. The system performance was optimized according to above measures.