Study On The Method Of Removing Foreign Objects In Raw Salt

In this paper,mechanical design,machine vision,aerodynamic technology,optics,electronic control,and other relevant theoretical knowledge are comprehensively applied.Taking raw salt as the research object,the method of real-time online detection and removal of foreign bodies in raw salt based on machine vision technology is explored.The main research contents and conclusions of this paper are as follows:Aiming at the problem that raw salt particles are easy to accumulate and unevenly distributed,which is not conducive to image acquisition,this paper adopts the method of vibration feeder and conveyor belt in the feeding module designed by hardware.The distribution of raw salt can be significantly improved,which is beneficial to the image acquisition of the visual detection module.At the same time,in order to ensure the quality of the raw salt image collected,during the design of the visual detection module,strict parameter calculation and performance considerations were carried out for each hardware selection of the visual module.In order to ensure the detection accuracy of the raw salt foreign objects detection and selection systems,a line scan camera calibration method based on the rotating platform is proposed in this paper.The position of the fixed line scan camera is unchanged,and the calibration plate of a self-made line scan camera is adopted.The point of the space line formed by the light plane of the line scan camera and the calibration plate plane is used as the origin of the world coordinate system.By using cross ratio invariability to find the object point,the function with internal camera parameters is solved non-linearly,and the camera internal and external parameters can be marked.The calibration precision of this method can reach 0.1mm and meet the requirements of the detection standard.This paper uses the HALCON image processing algorithm library to process the raw salt images collected by a line scan camera.The median filtering algorithm is selected to remove the noise in the raw salt image,and the fixed threshold segmentation algorithm is used for binary processing of the raw salt image.The image is operated by a morphological processing algorithm,and the final result is obtained by image feature filtering.At the same time,the multithreading technology is integrated into the software design to realize real-time synchronous detection and elimination of raw salt inspection and selection system.Finally,the correctness of the detection of the salt foreign body reached 99%.In this paper,a mechanism for removing foreign objects from raw salt is designed.Considering the large mass of some of the foreign objects in the raw salt,the method of cylinder strike is adopted to remove the foreign objects salt particles during the falling process of raw salt.In order to ensure the elimination rate of the raw salt detection system,the time axis of each module in the system is analyzed in detail.The key parameters of the upper and lower computer are determined,and the key parameters of the elimination mechanism are optimized.The results show that the falling state of raw salt is stable and evenly distributed when the distance between the conveyor belt and the camera is 700mm.Meanwhile,the actual distance between the camera and the culling device is mainly determined by the sum of the time of each module of the system.After calculation and analysis,the result is 37ms,and then the actual distance between the camera and the culling device can be determined to be 143mm.On the basis of the above research,the system is tested as a whole.The feasibility of this method is verified by experiments,and the experimental results are analyzed.