The Research Of Pecan Collection Device Based On The Developable Mechanism

At present in pecan harvest has also been used the most primitive way ofcollection, namely artificial bending over to pick it up with his hands, and this way ofcollecting time-consuming, not only the harvest efficiency is low, and the laborintensity is big, so study a pecan collection device so as to realize the mechanizationof pecan collection, improve the efficiency of harvest, has the very vital significance.In this paper, combined with the actual application requirements, themovement mechanism of the space deployable mechanism are analyzed and studied,selected on the movement mechanism of shear type hinge unit structure to improvethe design and optimization, developed a portable pecan collection device. Concretework contents completed are as follows:1) Refer to the literature of domestic and foreign, on the domestic and foreignexisting deployable structures are summarized classification and characteristics,andcomparative analysis of their advantages and disadvantages, the final choice toimprove the shear type hinge unit structure design, developed a kind of deployablestructures used in pecan collection device.2) According to the functional requirements of the collecting device, separatelyon the scissor hinge unit is circular and parabolic shape design, according to these twokinds of design methods of contrast analysis results, choose the circular arc shapedesign as the design collection device main body deployable structure method, at thesame time, according to the circular arc method for shape design, using the MATLABsoftware developed the parameterized design and simulation software of the mainbody deployable structure, and use the software to analysis the relationship betweenthe rod length and the span of structure expansion.3) According to the characteristics of the main body deployable structure, to design the overall structure of the collection device, and through the Solidworkssoftware to complete the modeling and the overall assembly of parts of the device,atthe same time using the ADAMS simulation software for collecting device movementsimulation, verify the correctness of theoretical analysis and the feasibility of themovement.4) Using finite element method to establish the main body stretching structurefinite element model, and through the modal analysis to grasp the bar diameter andwall thickness changes impact on the natural frequency of the structure,at the sametime, quantitative calculate the pecan whereabouts on the main body stretch structureimpact force, and has carried on the static analysis using ANSYS software, accordingto the results of the analysis, the main extension structure in the outer diameter andwall thickness of the rod piece is optimized by using ANSYS software, when thestructure is a span of3.5m,get the best of bar size parameter is: outer diameter D=22mm, wall thickness H=0.5mm.5) In order to seek to make the main extension structure capable of kinematic anddynamic parameters of the stable expansion,the main extension dynamic bindingstructure in the development in motion are solved by using the dynamic static method,and the dynamic equations of the system was established by using Lagrange method;Procedures for solving dynamic equation was written by using MATLAB softwareand its solution was completed,the correctness of the analysis method is verified byADAMS software. The analysis results show that, the driving force F=24N is exertedto the slider, the slider speed steady change in the range of0-0.022m/s, the mainextension structure development is the most stable.6) Completed the test platform of collecting device trial-manufacture, and byfolding and expansion test, verify the validity of the design method of circular arcform informs and the feasibility of the movement.