Design And Research On Tractive Orchard Picking Platform

China is a fruit growing and producing countries,but most of the current domestic orchard harvest still rely on manual labors,the domestic orchard harvesting platforms can not meet the actual demand.At the same time,picking robots are in the phase of laboratory research,which are difficult for large-scale applications in the short term.Therefore,the research and development of picking platforms being suitable for the modern orchards is in accordance with the current trend.In view of the above situation,this paper put forward a kind of orchard picking scheme,designed and developed the tractive orchard picking platform,as well making the prototype and experiments.The main contents and conclusions are as follows:(1)This paper analyzed the present situation about the research and development of the domestic and foreign orchard platforms,found the problems existing in the research and development of the orchard equipment in our country.Based on the comprehensive analysis of the above,this paper proposed a scheme called “both sides,three bilateral height,six station”,which was based on artificial picking and suitable for dwarfing close planting orchards.This scheme tried to solve the problem of insufficient height by artificial picking by the method of stratified operation.It realized the whole process from picking to packing,increased the continuity of harvesting,greatly improved operating efficiency,and reduced labor intensity.(2)Main parameters of this platform were determined,thereinto,the minimum width of platform was 2.5m,the optimum picking height were 0cm,80 cm and 140 cm.The adjusted height of picking workbench were 0cm,20 cm,40cm and 60 cm.Those were combined with modern orchard line spacing,trees height,crown width,and other data.We also applied the principle of ergonomics and CATIA software ergonomics to design the platform’s size parameters.On this basis,3D models were built,working principle was established,and the preliminary design of tractive orchard picking platform was completed.(3)The fruit conveying system,driving and controlling system,the running system and the fruit box bearing and falling mechanism were designed comprehensively.The scheme of the fruit conveying system involved fruits mechanical damage theory,and implemented by three degrees of transmission devices.Structure sizes,working principle and space layout were designed and analyzed in detail.The driving and control circuit of the platform were researched,which focused on the automatic lifting control system and the actuator of the vertical conveying device.The results showed that the delivery scheme was feasible and met the transport requirements(4)We conducted a large number of analysis and calculation of key components.With making the best of the relevant knowledge including mechanical design,theoretical mechanics,material mechanics.With the aid of computer software ANSYS,we conducted finite element analysis,mainly aimed at the stress condition of the chassis and the picking workbenches,checked the strength of the axle.In addition,the transmission system of the vertical transfer device was designed and calculated.It was found that,the maximum deformation of the chassis was 3.62 mm,and the maximum stress was 65.69 MPa.The maximum deformation of the axle was 0.05 mm,and the maximum stress was 87.26 MPa.Both of those strength met the actual requirements.The maximum deformation of picking workbench was 1.81 mm,and the maximum stress was 60.62 MPa,which met the actual requirements.But picking workbench had the problems of lack of brace and stress concentration,which could be improved by increasing the support units.(5)Several experiments had been conducted on the prototype.The experiment results showed that the main technical parameters of the prototype were basically in accord with the design values.The vertical transmission device automatic lifting control system could well realize automatic lifting,and the relative error was less than 4%.The transmission efficiency of the fruit conveying system reached 8EA/s,but the fruit damage rate in high speed exceeded 10%.Running with tractor traction,the minimum width of the edge space required for 5.07 m when the platform turned around spacing two lines of fruit trees,and the minimum width of the edge space required for 4.92 m when the platform turned around spacing three lines of fruit trees.The minimum turning radius of this platform was about 4.86 m,the wheels running width was about 2.74 m,which met the operating requirements in orchards.