Study On Ear Picking Of Corn Based On Excitation Theory

In this paper,aiming at the bottleneck of improving the quality and reducing the cost of corn harvest and restricting the development of corn harvest mechanization technology,combined with the results of low loss,high efficiency and low power consumption harvest technology,the vibration wave structure,the design of multi edge ear picking roller based on the vibration theory,the ear damage and movement rules based on the vibration ear picking are analyzed and tested In this paper,the mechanism of exciting ear picking is studied:(1)In view of the problems of serious grain gnawing and large loss of falling grain existing in the operation of vertical and horizontal roller type corn harvester at present,a theoretical model of corn picking by exciting vibration suitable for Corn Mechanized Harvest was established under the guidance of exciting vibration theory and the condition of separating corn ear and stalk.(2)The theory of maize ear picking mechanism was studied based on the advantage of high efficiency and low-loss,and the influence of the clamping position,vibration frequency and amplitude on the effect of maize ear picking was determined.We have established the shocking spike model and determined the frequency characteristic curve suitable for the high efficiency and low-loss spike of maize.We have adopted the shocking and snapping experimental table designed by our own project team,carried out the single factor influence rule of the clamping position,amplitude and frequency on the performance of snapping,and determined the parameter range to satisfy the ear picking of corn.Under the condition of clamping position 10.25?13.25 cm,amplitude 0.5?1cm and exciting frequency 15?18.3Hz,it has an ideal exciting effect.Based on the single factor test analysis and in order to ensure the best picking effect without breaking the stem,we have uesd the response surface methodology to study the change rule of spike removal after coupling parameters.Through response surface ANOVA analysis,the response regression equation of the effect of clamping position,amplitude and frequency on stem breaking rate and picking success rate was obtained.And combination wiht the response surface image,the specific influence of clamping position,amplitude and frequency on stem breaking rate and picking success rate were obtained.Finally,through parameter optimization,we determined the best parameter combination suitable for maize high efficiency spike removal.That is to say,when the ear of corn with a water content of30%?45%,its clamping position is 10.8cm from the barycentric of the corn era.When the amplitude is 0.6cm and the excitation frequency is 17.8Hz,The stem breaking rate of maize was 2%,the success rate of picking was 98%.The results fully meet the technical requirementsof the corn harvest,and provide theoretical support for the development of the corn harvester.(3)Under the guidance of the model,the shape structure and configuration of the ear picking roller were constructed and optimized,and the corresponding experiment platform was developed.Box-Behnken experimental design method was used to study the effects of key parameters such as edge number,amplitude and rotation speed of excitation picking roll on grain loss rate and gnawing rate during ear picking.The regression equation between experimental factors and inspection indexes was established,and the corresponding response surface was generated.The results showed that the number of edges,the amplitude and the rotation speed of the picking roll had significant effects on the grain loss rate and the gnawing rate during harvesting.Finally,under the guidance of the theory of non-linear programming,the best combination of the above three experimental factors is established,namely,the rotation speed of the picking roll is 950 r/min,the number of edges is 8,and the amplitude is 0.75 cm.Under these conditions,the average loss rate of corn grains during heading process is 0.228%,and the average breakage rate of corn grains is 0.124%,which is lower than the national technical standard of corn harvesting machinery,which provides theoretical support for the popularization and application of this technology.(4)In order to analyze the essence of low loss and high efficiency ear plucking and promote the transformation of this technology to productivity,ADAMS dynamic simulation technology is used to simulate the force and movement of ear in the process of ear plucking,determine the law of ear movement and reveal the mechanism of low loss and high efficiency ear plucking.Furthermore,the movement law of the ear in the process of ear plucking was obtained by using the exciting test-bed and high-speed camera technology.The correctness of Adams dynamic simulation analysis was verified.It was also proved that the grip of the fruit stalk was the condition of ear plucking,and the exciting force was the fundamental guarantee for the separation of the ear and the stalk.The fundamental reason for the high-efficiency and low-loss harvest of ear plucking by exciting was revealed.For the sake of improving and optimizing the exciting force The structure and parameters of ear vibration provide a theoretical basis.(5)In order to explore the power consumption of the developed exciting ear picking device and the difference between it and other ear picking methods,and to provide the design basis for determining the power of starting rate,gearbox and transmission system,an exciting ear plucking torque collection test-bed was set up,and the power consumption of ear plucking under multimodal excitation was tested.The results show that the power consumption of the device is lower than that of the conventional device,and the average power consumption of the device is 44.9% lower than that of the conventional device under the optimal parametercombination.Further,in order to explore the internal relationship between the power consumption and the design parameters in the process of exciting ear picking,this paper studies the power consumption law in the process of exciting ear picking based on the experimental factors of amplitude,number of edges and rotation speed of the ear picking roller.The results show that the power consumption in the process of combining the parameters of exciting ear picking is lower than that of the conventional ear picking device,and the power consumption in the process of exciting ear picking is mainly affected by the number of edges of the ear picking roller The optimized parameters are amplitude 0.72 cm,number of edges 8,rotation speed 944r/ min and power consumption 108.92 W,which are consistent with the results of previous tests.