Research On Soil Surface Quality Detection And Control Of Tillage And Sowing Combined Operation Machinery Compartment

The surface quality is an important parameter to evaluate the operation effect of agricultural machinery,and it is also one of the key problems to be solved in the development of precision agriculture.General crop seeds have high requirements for the quality of compartment work when sowing,especially small-sized seeds such as rapeseed and cabbage.The quality of compartment directly affects the germination of seeds and subsequent growth and yield.In this thesis,aiming at the unevenness of seedbed preparation due to different physical conditions in the field during the combined mechanical operation of tillage and sowing,and the practical problem that it is difficult to accurately quantify the surface quality in real time by manual work,based on the systematic analysis of relevant technologies at home and abroad,in order to prepare a more uniform seedbed,the detection and control method of the surface quality of the seedbed of tillage and sowing machinery is studied.The main research contents are as follows:(1)The dynamic measurement system of working surface quality was built.Based on laser radar and camera,a vehicle dynamic measurement system is built to obtain soil surface elevation data and van image data in real time.The verification test results show that the correlation coefficient between the dynamic measurement system and the static measurement system is 0.92,which has a high correlation.(2)The classification of soil particle size was studied.In order to improve the speed and accuracy of soil block detection,the cosine annealing learning rate and SENet channel attention mechanism are combined on the basis of the original Mask-RCNN algorithm.The AP value of the improved model is increased by 25.3 % and the R value is increased by8.9 %.In the large-scale soil particle size detection after tillage,the average confidence is above 97 %,and the soil particle size distribution can be effectively counted.The correlation between soil particle size and mass was analyzed,and the conversion method of estimating soil crushing rate by soil particle size was established.(3)The surface roughness quantification method was studied.In order to remove the directional roughness information introduced by furrow undulation,this thesis uses wavelet transform to accurately quantify the soil surface roughness.The comparative experimental results of different ditching depths and whether the surface is agglomerated show that the directional roughness component formed by the furrow has a significant effect on the calculation of soil surface roughness.The field experiment after tillage proved that the wavelet transform can effectively weaken the anisotropy and multi scale of ridge and furrow structure formed by furrow opener on the surface of the box during tillage sowing combined with mechanical operation.(4)The design of variable tillage intensity control system and field verification test were completed.The existing tractor hydraulic lifting mechanism was modified by electronic control to realize automatic adjustment of rotary tillage depth.A variable tillage intensity control system based on real-time feedback of van surface operation quality was designed.The tillage intensity of tillage-sowing combined operation machinery can be adjusted in real time according to the quality monitoring of van surface roughness and soil crushing rate to prepare a more uniform seedbed.The field verification test shows that the variable tillage system based on the real-time feedback of the dynamic measurement system meets the design requirements,which can provide reference for the quality monitoring of the working surface of the tillage and sowing machinery.