Development Of Mobile Platform For Tea Garden Management Machine In Hilly And Mountainous Areas

China is the world's largest tea plantation area of the country,more than 60% of the tea plantation distribution in the hills and mountains.However tea plantation mechanization management level is low in our country,especially in the hilly tea garden cannot realize mechanization management,cultivated land,furrowing,fertilization,turns the soil,weeding,spraying,such as homework all rely on artificial to complete,not only the intensity of labor is big,the efficiency is low,and with the improvement of labor costs constantly,greatly improve the cost of tea production.The key to realize the mechanization of tea garden management in hilly and mountainous areas is to develop a multi-functional tea garden management machine mobile platform suitable for the tea garden topography in hilly and mountainous areas.The domestic and international researches on the mobile platform of multifunctional tea plantation management machine which is suitable for the hilly and mountainous areas of our country is very limited,which integrates arable land,ditching,fertilizing,mulching,weeding and spraying.This article through consulting a large number of relevant literature,and in combination with the practical situation of our country's at present hilly tea garden management,further investigate and understand the actual demand of the tea garden management,developed a can implement of cultivated land in hilly tea garden,weeding,furrowing,fertilization,turns the soil and spraying function of tea garden management machine multi-function mobile platforms.Based on the analysis and research of the structure and working principle of the mobile platform,combined with theoretical analysis,computer simulation and experimental research,the mobile platform of tea garden management machine was developed and verified by relevant tests.The main research contents are as follows:(1)combined with the actual conditions and agronomic requirements of tea gardens in hilly and mountainous areas,considering the passing,dynamic and adaptability of multi-functional tea garden management machine in the field,we developed a self-propelled multi-functional tea garden management machine mobile platform capable of carrying different operating machines and tools,so as to realize the function of "multi-use of one machine".The mobile platform is 750mm~950mm in height,385 mm in width and 1330 mm length,powered by a 2.2kW gasoline engine and 12 v battery.(2)According to the actual load of the mobile platform,the mechanical analysis equations of the mobile platform are established,the efficient finite element analysis model of the mobile platform is established,and the actual load and constraints are loaded.The static analysis of the mobile platform is carried out by using the finite element analysis software ANSYS Workbench.Finally,the static characteristics of the mobile platform under the maximum load condition are analyzed,and the equivalent stress and deformation of the mobile platform are explored.The maximum equivalent stress is 87.87 mpa,the maximum deformation is 7.773 mm,and the safety factor is 2.67,which shows that the mobile platform meets the design requirements of stiffness and strength,but there is large material redundancy,with optimization space.(3)ANSYS Workbench is used to optimize the design of mobile platform.The overall structure of mobile platform is improved by topology optimization,and the quality of mobile platform is reduced.Seven design parameters of the mobile platform are selected for multi-objective optimization,the specific size parameters of the optimized mobile platform are determined,and the mechanical properties of the optimized mobile platform are analyzed.After two-stage optimization,the quality of the mobile platform decreases by 31.2%,the maximum deformation decreases by 7.9%,and the safety factor is 1.57.The optimized mobile platform meets the design expectation.(4)Conduct modal analysis on the mobile platform,and obtain the external excitation frequencies of the mobile platform from 0.16 to 1.56 Hz and 5.67 Hz through theoretical calculations.Simulation analysis of the optimized natural frequency of the mobile platform shows that the first six natural frequencies are 11.98 Hz,19.98 Hz,36.91 Hz,61.40 Hz,86.64 Hz,87.20 Hz.The analysis shows that the natural frequency of the mobile platform is not the same as its external excitation and is similar,indicating that the mobile platform has good modal performance and is not prone to resonance.(5)Prototype manufacturing and testing.Trial mobile platform and Assemble the whole machine.Through simulation and optimization design,the quality of the mobile platform was reduced from 9.24 kg to 6.54 kg.After trial production of the optimized mobile platform,the results showed that The mass of the optimized mobile platform is 6.97 kg,which is 6.6% different from the simulation results,which was within a reasonable error range.within.Assemble the whole machine and conduct a field walking test by replacing different agricultural machinery.The test results show that the mobile platform has the fastest driving speed of 0.98m/s in the tillage,weeding,and ditching fertilization modes,which meets the design requirements.The frame has good vibration characteristics and is easy to handle.Weeding,ditching and plowing field performance tests were carried out on the mobile platform.The test results showed that the mobile platform of the tea garden management machine had a significant effect on weeding;the ditching width under the ditching operation was 198 mm,the depth was 177 mm,and the ditch depth stability system 86.4%;the tillage width under the tillage operation is 607 mm,the depths of deep tillage,middle tillage and shallow tillage are 198 mm,122mm and 96 mm respectively,and the stability coefficients of tillage depth are 87.6%,85.6% and 82.8% respectively.According to the “Notice on Printing and Distributing Technical Guidance on Tea Garden Mechanized Production” issued by the General Office of the Ministry of Agriculture in December 2017,the requirements for tea garden fertilization and cultivation,as well as the actual weeding effect,indicate that the mobile platform weeding,trenching and tillage operations basically meet the hilly and mountainous areas Tea garden management agronomic requirements.