Design And Study On Soil Cleaning And Film Recognition Components Of Film Stripper For Tabacco Seedling

The mulching film cultivation method is an important technical to improve the yield and quality of crops,however the mulch film is difficult to degrade under natural conditions.As the residual amount of mulch film increases year by year,problems such as farmland pollution and“white pollution”are becoming serious.As an important economic crop in China,tobacco is widely used in the cultivation of plastic film mulching.Covering the film at the beginning of the seedling can effectively ensure the development temperature of the seedlings,and its heat preservation and preservation can significantly promote the growth of tobacco seedlings.At the middle and late stage of tobacco plant growth,the temperature increases and the film has an inhibitory effect on the growth of tobacco plant.At the same time,the film strength is relatively good at the seedling stage,and the film is easy to be recycled,so it is necessary to remove the film at the seedling stage.However,due to the fact that the slab soil in the film uncovering process will seriously limit the work of the the plastic mulch removal.The paper has carried out the design research on the slab soil cleaning device of the film uncovering machine,in order to solve the problem of film mulching recovery in the soil compaction in hilly areas.And it is of great significance to promote the green development of agriculture and the process of agricultural mechanization.The clearing film-receiving device designed by the thesis includes a mechanical part mainly composed of DC push rod motors and a shovel blade,and an image processing part mainly composed of a camera and a controller.The overall working mode of the device is that,first the controller issues a command,so that the shovel is driven by the push rod motor,and the image is collected by the camera after each ploughing to determine whether there is a mulch film.If there is no mulch film,the device continues to work,and if it does,it stops working and so cycles,so as to clear the soil of the slab to remove the film.The main research contents are as follows:(1)Design the scheme of the film uncovering machine in the tobacco field,and carry out 3-D modeling and virtual assembly of the mechanical structure of the whole machine,and make the structure as compact as possible while avoiding mechanical interference.(2)Structural design of the device,study the stress condition and separation mechanism of the device when cleaning the mulch film mulch.Analyze the composite resistance of the device during soil cleaning and conduct related tests.The maximum shearing force and planing force of the soil shovel are 73.97N and 57.94N,respectively,and the appropriate DC push rod motor is selected according to the test data.(3)The processing algorithm of the image was studied.Firstly,the calibration camera was calibrated,the imaging mechanism of the camera was analyzed,the advantages and disadvantages of the current camera calibration algorithm were compared.The Zhang-Zhengyou calibration method is selected to calibrate the camera.The black and white checkerboard is used as the reference object to extract the corner points as features,obtain the internal and external parameters,remove the distortion effects,and compare the results under different calibration distances.The field film image is collected and image segmented,and then the segmented image is subjected to morphological filtering operation and connected domain deconstruction.Finally,the target region is subjected to boundary tracking separation and extraction,and the geometric information such as the area and perimeter of the film in the image is collected,also to determine whether there is mulch.The eigenvalue range of the recognition algorithm ranges from 4,500 to 20,000mm~2,the area is 4%to 22%,and the circumference is 250 to 950 mm.The three conditions are satisfied at the same time.(4)Study the control strategy of the clearing device and complete the corresponding modular circuit.Combined with the camera,the whole work is connected through the controller to complete the work of clearing the soil.The relevant tests are carried out on the device,and two sets of tests are designed to test the working accuracy of the shovel and the work of the device to verify whether it meets the design requirements.The tests show that the control accuracy of the soil cutting position of the device is relatively good,and the displacement error does not exceed 1mm.The average recognition rate of the mulch film is higher than 95%,the film damage rate is less than 3%,and the average soil removal rate is over 80%.The test results are good and meet the design requirements.