| In order to pursue aesthetic appearance,molding products made by IMD film use curved surface in large quantity,while traditional punching and cutting die is helpless when cutting IMD film boundary of complex surface.In addition,traditional punching and cutting is difficult to adapt to the requirements of modern personalized small-batch production,so we need to find a flexible cutting technology.The 3d laser cutting robot can not only complete the complex cutting trajectory but also change the cutting path rapidly to meet the cutting needs of different diaphragm without additional cost.However,in the edge cutting test of 3d laser IMD film,it is found that the deformation of the formed film itself,such as warping and springback,can lead to laser focus deviation,uneven energy distribution on the surface of the film,yellow burning or impermeability of the film.In order to solve this problem,a feedback system of diaphragm deformation is introduced in this paper,and the center distance of laser double spots is captured by CCD camera to calculate the shape variable of the diaphragm and compensate the laser track accordingly.The main contents of this paper are as follows:(1)A feedback measurement and track compensation system is designed according to the action mechanism of laser cutting affected by the deformation of the diaphragm.It is found that the trajectory shift and defocus change occurred when the 3d laser cut the diaphragm according to the off-line program due to the deformation of the formed diaphragm such as its own warp and springback.Therefore,a feedback measurement system is designed,which calculates the shape variables of the diaphragm and compensates the cutting track according to the center distance of the laser shadow projection and calibration on the diaphragm.(2)Design an opencv-based algorithm for double spot center distance extraction.An opencv-based laser spot extraction algorithm is designed based on the analysis of effective spot information and common interference information in the actual picture.The fast measurement function of the center distance of light spots is realized by image preprocessing,image effect enhancement,interference spot removal and long axis extraction.(3)Design the trajectory compensation control model.The mathematical relationship between the center distance of the double light spot and the deviation of the laser focus at the deformation of the diaphragm is determined by geometric relations.The influence of laser defocusing on cutting quality and the allowable error range of the defocusing amount of diaphragm laser cutting are obtained through experiments.The path compensation control model based on fuzzy algorithm is constructed.(4)The cutting effect of the track compensation system was verified by IMD film cutting experiment.The experiment USES the edge cutting tools to recover the reversible deformation,and USES the compensation system to compensate the trajectory of small deformation films such as warping and springback,which improves the yield of the laser edge cutting of the diaphragm.The innovative point of this paper is to compensate the laser cutting track of deformable diaphragm by using image processing technology and fuzzy control algorithm according to the deformation of bifocal distance feedback diaphragm and to design the laser cutting edge treatment scheme of deformable diaphragm.The new scheme and track compensation system improve the yield of IMD diaphragm laser cutting,which is of great significance in production practice. |
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