Research On Structure Design Of Fiber-optic Counter For Storage Grain Weevil

The stored grain weevil is the main pest of China's stored grain,and it is also a worldwide pest of stored grain.Harm to rice,wheat,corn and other stored grain crops.Accurate and efficient counting statistics for stored grain weevil is an important prerequisite for accurately grasping the degree of pests.Because the weevil is small and moves,it undoubtedly increases the difficulty of counting statistics.At present,the statistics of the fixed number of laboratory insects and the number of elephant worms in stored grain are mainly artificial,with low efficiency,poor accuracy,and time-consuming labor.According to the characteristics and counting requirements of weevil,this paper studies the negative pressure conveyance,mechanical separation,and optical fiber counting of worms for the purpose of realizing the automatic grabbing and counting of weevil.The fiber counting device for storing food weevil is developed and developed to realize The automatic crawling and counting function of the target worms.The main contents of the thesis are as follows:The first part,the research and analysis of the negative pressure transportation system of stored grain weevil.This part is mainly to provide power for weevil sucking and separating.First,the overall overview,working principle and process of the weevil negative pressure delivery system are introduced.Then,the force of a single weevil in a negative pressure system was calculated and analyzed.The suspension speed of the weevil in the pipeline,the speed of the weevil's movement,the speed of the air flow required by the system to transport the worm,the air volume of the system's operation,and the appropriate fan was selected.The weevil separation device was introduced,and the separator was improved and optimized.In the second part,a connecting rod separating mechanism for separating a single weevil is designed.This part mainly focuses on the separation of individual weevil and the corresponding counts.First,the size parameters and motion characteristics of the target worm were measured and experimentally analyzed,which provided the original basis for the size design of the diffuser and the connecting rod.Then,the influence parameters of the connecting rod are simplified by Fourier transform of the crank-rocker mechanism,and thelength feasible region of the connecting rod is obtained by using MATLAB.The motion trajectory simulation analysis of the connecting rod length in the feasible region is obtained,which meets the requirements Dimensional parameters of the crank link mechanism;after selecting the curve of the link,verify the rapid return characteristics of its movement.Finally,a three-dimensional link model is established and assembled,and the displacement,velocity,and acceleration simulation results of the link are obtained.In the third part,the design of the photoelectric counting device is investigated.In this part,the counting device is analyzed and improved in order to improve the accuracy of weevil counting.Analyze the applicable characteristics of various counter probes,and select the best fiber optic probe as the system detection and counting device.A reasonable choice was made for the placement and reflection of the fiber optic probe.The sensitivity of the counting system was determined by combining the speed of weevil in the pipeline,and the rationality and correctness of the selection were verified.Finally,during installation in the pipeline,a fiber diffusion device was designed and the optimal detection distance between the weevil and the fiber probe was determined,and the structural parameters of the fiber diffuser were reasonably designed.The effect of different materials of the fiber diffuser on light intensity was analyzed,and a black light diffuser was selected.In the fourth part,debug and optimize each device.This part is mainly to optimize the working performance of the counter.A three-dimensional model of the fiber optic counter for grain storage was established,and the model was printed and manufactured by a 3D printer,and the prototype of the fiber counter of the worm was assembled.The structure design of the fiber optic counter of the target insect was modified and optimized.After the prototype was completed,a performance test was performed to investigate the influence of the link speed on the counting efficiency and accuracy.