Development Of Orchard Remote Control Mower With Automatic Adjustable Swing Blade Height

China is a big country of fruit production and planting.In order to meet the growing demand of the market for fruit,mechanized production management has become an important means to improve the output of orchard.Due to the low level of orchard mechanization,the development of fruit industry is restricted.In order to increase the fruit yield,it is an inevitable trend to increase the investment in orchard mechanization.In many orchard mechanized operations,mechanized weeding is one of the important measures to improve fruit yield.Most orchards in Southwest China are distributed in Hilly and mountainous areas.When working in Hilly and mountainous areas,ordinary mowers have the problem of difficult operation,which seriously hinders the progress of weeding mechanization in Hilly and mountainous orchards.In order to improve this situation and promote the development of mountain fruit industry,it is of great practical significance to develop a mower that can adapt to the terrain of Mountain Orchard.In order to solve the problem of complex terrain in hilly orchards and the difficulty for ordinary mowers to operate effectively,this paper designs a kind of orchard remote control mower with automatic adjustable swing blade height(1)By consulting the relevant literature at home and abroad,investigating the current situation of orchards in hilly areas and the specific requirements of mowers,and combining with the relevant horticultural requirements,the overall structure,technology and overall objectives of mowers were determined.In order to adapt to the hilly orchard terrain,the maximum working slope of the mower is 25 ° and the relevant horticultural requirements stipulate that the remaining height of the grass pile after the mower is in the range of 5-10 cm.In order to meet the relevant horticultural requirements and the actual mowing needs,the stubble height of the mower developed in this paper is preset based on the height requirements.Under the preset conditions,in order to ensure the stability of the stubble height of the mower in the operation process,the absolute height of the mower swing blade can be automatically adjusted with the change of the terrain height,so that the relative distance between the lowest point of the swing blade and the ground remains basically unchanged;in order to ensure the trafficability of the machine,the power system adopts the remote four-wheel drive chassis.(2)The structure of the cutter is designed and studied.It is determined that the mower’s cutter adopts swing blade structure,and the blade adopts L-shaped cutter.Through the kinematic analysis of a single blade,it is determined that the minimum speed of the blade is 1800 rpm,and the ratio of the speed along the blade and the moving speed of the mower is greater than 1.Through the dynamic analysis of a single blade,the cutting force of the blade is 83.75 N,which meets the minimum requirements of cutting weeds.Through the analysis of the motion balance of the cutter roll in ADAMS,and using the two side balance theorem to eliminate the dynamic imbalance of the cutter roll,the resultant force of the two end faces of the cutter roll is stable at0.285 N and 0.7729 N,and the dynamic imbalance is basically eliminated.(3)The design and research of cutting height automatic lifting system,including the design and research of cutting height automatic lifting system,including the design of detection mechanism,lifting mechanism,transmission mechanism and control system.Through the design of the detection mechanism,the terrain change which is not easy to detect is transformed into the distance change between the top of the vertical bar and the laser displacement sensor which is easy to detect.The lifting mechanism adopts the design of three-bar rotating mechanism,and its rotating center coincides with the center of the small pulley driving the cutter roller,so that the belt is always tight during the lifting process of the cutter.The parameters of the linear push rod are determined according to the velocity of the lowest vertical movement of the tool.Through the design of the transmission system,it is concluded that the primary belt transmission structure adopts 5 A-belts,the reference diameter of the small pulley is 80 mm,the reference diameter of the large pulley is 95 mm,and the reference length of the belt is 790mm;the secondary belt transmission structure adopts 3 A-belts,the reference diameter of the small pulley is 85 mm,the reference diameter of the large pulley is 95 mm,and the reference length of the belt is 1400mm;the minimum diameter of the transmission shaft is 25 mm,and according to the design Check,meet the use requirements.(4)The power system is designed and studied,and the drive scheme of remote four-wheel drive is determined.According to the walking speed requirements and body weight,the size of the walking wheel and the parameters of the walking motor are determined.(5)The development and experimental analysis of orchard remote control mower with automatic adjustable swing blade height were carried out.According to the design parameters,the prototype is manufactured,and the field test is carried out.The test is divided into two parts.The first one is to test the automatic adjustment of the swing knife height.The test results show that: the actual lifting height of the swing knife is basically consistent with the actual height difference,indicating that the swing knife height can be adjusted automatically according to the terrain fluctuation,so as to ensure that the relative distance between the lowest point of the swing knife and the ground is basically unchanged,so as to ensure the stability of the stubble height.Second,the performance of the mower was tested,and the stability coefficient of stubble,utilization rate of cutting width and leakage rate were used to test and analyze the prototype.The results show that the average stubble stability coefficient is 94.75%,which is higher than the evaluation standard of 90%;the average cutting width utilization rate is 92.52%,which is higher than the evaluation standard of 85%;the average missing cutting rate is 1.22%,which is lower than the evaluation standard of2%.The mower has good mowing effect and meets the acceptance specification for swing blade mower(GB / T 25397-2010).