Study On The Mechanism And Device Of Biomimetic Ear Picking For Fresh Corn

Fresh food mainly includes sweet corn,glutinous corn,and sweet glutinous corn,which are highly favored by consumers due to their delicate taste,high sweetness,and high nutritional content.In recent years,with the increasing demand for fresh corn,its planting area has been expanding year by year.However,the degree of mechanized production of fresh corn is relatively low,especially in mechanized harvesting.Most regions in China still use manual harvesting or ordinary grain corn harvesters for harvesting fresh corn.Due to the short timely harvest period of fresh corn and the high moisture content of the ears during harvest,the wrapping leaves must be kept intact after harvest,thus placing high requirements on the operational performance of harvesting equipment.Most of the existing fresh corn ear harvesters at home and abroad have problems such as high impurity content,high damage rate,high power consumption,and low intelligence in harvesting ears.Therefore,it is of great practical significance to design and develop ear picking devices suitable for harvesting fresh corn,in order to reduce ear damage during the harvesting process,reduce power consumption and impurity content,improve efficiency,improve the mechanization of fresh corn planting,respond to the market,expand demand,and increase farmers’ income.This study is based on the physical characteristics and mechanical research of fresh corn plants,and based on the artificial picking mechanism,a biomimetic fresh corn picking device has been designed and developed,and its working mechanism has been thoroughly studied.This study breaks through the key technologies for harvesting fresh corn,achieving the goal of reducing ear damage rate,reducing power consumption,reducing harvest losses,and improving automation.(1)This article analyzes the working characteristics,performance indicators,and existing problems of existing fresh corn picking devices both domestically and internationally,and proposes a solution based on simulating the artificial breaking process to reduce collisions,squeezing,and pulling during the picking process.Through the rigid flexible coupling operation process of the mechanism,a biomimetic picking of fresh corn is achieved.(2)Based on the ridge planting mode of fresh edible corn in the Northeast region,combined with the field growth stage of the plant,the basic physical parameters of the plant during the harvest period were measured,including the mechanical properties of the fresh edible corn stem and the physical parameters of the ear,and the shear load displacement relationship curve of the stem was obtained;Analyzed the mechanism of artificial ear breaking and harvesting,and conducted a comparative experiment on the positive and negative breaking forces of fresh corn ears.Proposed the research direction of this article,which is the bionic ear picking method.Analyzed the principle of bionic ear picking,and provided a theoretical basis for designing bionic ear picking devices.(3)By conducting in-depth research on the mechanism of biomimetic ear picking,the mechanism design of the biomimetic ear picking device for fresh corn is completed.A flexible clamping conveying mechanism was designed to study the opposite feeding and clamping conveying of fresh corn plants.The guide wheels of the conveying belt were arranged in a staggered manner to maintain the clamping force on the stems during reverse biomimetic ear breaking operations,reduce the clamping,breaking,and blocking of the stems,and determine the working length and speed range of the clamping conveying mechanism;Researched and analyzed the cutting force between the stem and the cutting blade,designed the cutting blade mechanism,and determined the range of cutting blade speed;We studied the process of biomimetic bending and ear breaking,as well as the separation mechanism between stem and ear.We designed a biomimetic ear picking mechanism that mimics manual top-down bending and ear breaking,and determined the diameter and speed range of the ear picking roller.(4)The ADAMS software was used to analyze the picking mechanism of the separation of ear and stem,and the stress process of fresh corn stem and ear,as well as the bionic picking and harvesting process,were analyzed.Analyzed the fracture conditions of the ear stem when subjected to an axial force along the stem axis,resulting in the separation of the ear stem from the stem;Analyzed that the damage of ear and grain during biomimetic ear picking is mainly affected by the force exerted by the ear picking roller on the ear and grain during bending and breaking;Analyzed the influence of different rotational speeds of the roller group in the biomimetic ear picking device on the contact force between the ear and the ear picking roller,as well as the influence of different upward clamping speeds on the force on the ear,and obtained the range of values for the rotational speed of the ear picking roller and the driving wheel speed of the clamping conveyor belt;Through the statics analysis and modal analysis of ANSYS,the maximum stress value of the snapping roll is 1.496 MPa,the maximum displacement is 0.0021 mm,and the material Q235-A of the snapping roll meets the design requirements.(5)Design of the transmission hydraulic system for the biomimetic ear picking device of fresh corn.Through the analysis of the overall framework of the hydraulic transmission system,the design of the hydraulic circuit for height adjustment of the clamping mechanism,the hydraulic circuit for lateral transportation of fruit ears,the hydraulic circuit for cutting knives,the hydraulic circuit for clamping and transportation mechanism,and the hydraulic circuit for rotation of the picking roller were completed.The schematic diagram of the hydraulic system for the executing element was constructed,and the main component parameters were calculated and analyzed.The selection of the executing element and the construction of the hydraulic system were completed.Developing an automated control system for the biomimetic harvesting device of fresh corn,achieving control over the hydraulic circuit,execution mechanism,and other action mechanisms,processes,and completes signal acquisition,processing,real-time monitoring,and data storage;Developed and designed an adaptive adjustment function,implementing hierarchical adjustment of institutions and recording and calling of multi-parameter information;A fault alarm and maintenance assistance information have been designed to improve the reliability and automation level of the device.The performance test results show that the system can meet the requirements of biomimetic harvesting of fresh corn ears.(6)A multi-parameter combination controlled fresh corn biomimetic ear picking device test bench was established to arrange the experimental plan.The stem breakage rate and clamping accuracy were used as the experimental indicators,and the clamping conveyor belt speed,clamping mechanism inclination angle,and clamping conveyor belt gap were used as influencing factors.A regression model was constructed through a quadratic regression orthogonal rotation combination experiment.By using the Design Expert analysis software to analyze and optimize the experimental data,the optimal parameter combination of the bionic picking and flexible clamping conveyor mechanism for fresh corn was obtained.The clamping conveyor belt had a rotational speed of 342 rpm,an inclination angle of 19 °,and a gap of 6.0 mm.The average stem breakage rate and clamping accuracy rate of the experimental indicators were 0.46% and 94.0%,respectively.The field segmented repeated validation experiment showed that the average stem breakage rate was 0.55%,and the average clamping accuracy rate was 93.0%,which was basically consistent with the optimized results.(7)Taking the rate of ear damage,impurity content,and power consumption as the objectives,and taking the speed of the ear picking roller,the inclination angle of the clamping mechanism,the clearance of the clamping and conveying mechanism,and the forward speed of the unit as the influencing factors,the optimization experiment was arranged using a quadratic regression orthogonal rotation combination.The results showed that when the speed of the ear picking roller was 465 rpm,the inclination angle of the clamping mechanism was 19 °,the clearance of the clamping and conveying mechanism was 8 mm,and the forward speed of the unit was 1.2 m/s,the average ear damage rate was 0.88% The average impurity content of fruit ears is 1.3%,and the average power consumption is 3.1 k W.The experimental results meet the design requirements.Field production experiments were conducted on the horizontal combination of the above parameters,and the average ear damage rate was 0.87%,the average ear impurity rate was 1.22%,and the average power consumption was 3.0 k W,which is consistent with the results of the bench test.The above research results indicate that the designed biomimetic ear picking device for fresh corn has low mechanical damage,low power consumption,and good operational performance,which can meet the basic operational requirements for harvesting fresh corn ears and provide technical reference for further development of fresh corn harvesters.