| Peanut is one of the important oil crops, it has important significance for oilseed production in the world and the safety of edible oil in China. Though as the largest producer and exporter, peanut production especially the levels of harvesting mechanization technology and application are relatively low in China, the rising labor costs limits the development of peanut production.peanut picking is the necessary link in the process of peanut harvesting, mechanical picking determines not only the picking efficiency and picking rate, and also the loss rate of peanut pods and pods damage.this paper combines with the specialized research fund for the doctoral program of higher education project "peanut picking combine core institutions working mechanism and key technology" (project number:20122103110009) And the follow-up of National Science Foundation " Study on Research on the dynamic damage mechanism of full-feed peanut picking and the low damage picking device" (project number:51575367), in view of the low picking rate and high breaking rate of universal full-feeding axial single cylinder peanut picker, the status of peanut harvesting mechanization has been studied and analyzed deeply, and the features and the working principle of the existing peanut picker have been summarized as well, and a modular multi cylinder peanut picking test device is designed and developed, and the picking performance experiment is carried out. The study results could provide necessary reference for the design of peanut pick-up and picker under two-stage harvest pattern.The main contents and conclusions are as follows:(1) Experimental study on physical and mechanical characteristics of typical peanut plant. By peanut straw root tensile strength of experimental analysis of the impact of the relationship between the rate of peanut straw root aquifer, the peanut vine tendril moisture content and pod with straw root contact Rally mean, pod and straw root contact Rally mean, and regression analyses are carried on using SPSS and other software. Affect the relationship between the regression analysis and test results peanut moisture content of stem and stem tensile strength, stem shear strength. Pod picking the injury test analysis varieties under different moisture content on the modulus of elasticity, compression work shelled force relations impact indicators. Different the loading position peanut pod Stress Analysis, Research loaded position of the broken shell force significantly.(2) Analysis of picking mechanism and design of modular peanut picking test device. The main structures of test device are analyzed, and the mechanism analysis of test device is carried out. Three-dimension models of picking cylinders are set up by Solidworks software and the analysis of mode is carried out. the force of peanut plants moving in the cylinder while picking are analyzed, and the mechanical and motion characteristics are summarized.(3) Characteristics of the system on the principle of vibrating suction cleaning system study and structure design. Research the main cultivated peanut varieties picking machine extraction of the aerodynamic characteristics of the material. Study the various extraction material the floating coefficient and floating speed, peanut pod on testing and stress analysis calculations of floating the coefficient of variation of the biological properties, several fruit picking objects floating between the variation coefficients of extraction. Through the experimental results, the design winnowing system design parameters.(4) Of the modular peanut picking test device parameters single factor test to determine significant impact factor. By three factors quadratic regression orthogonal experimental design on seven kinds of cylinder combinations to study the effect of various factors on pod picking rate and breaking rate, the influence order of experimental factors on the indexes is obtained. By the mathematical model, the dual function curved face of the factors affecting the test indicators for analysis; nonlinear multi-objective optimization theory and methods to determine the optimal parameters of seven kinds of cylinder combinations, and the picking distributions of seven kinds of cylinder combinations are analyzed.(5) Performance testing of modular peanut picking test device. The optimal parameters, indexes and picking distributions of seven kinds of cylinder combinations are analyzed and compared, and the optimal cylinder combination is determined to be axial flow single cylinder. It’s optimal indexes under optimal parameters(feeding quantify:0.46kg/s; picking clearance:25.3mm; rotating speed:497r/min) are:picking rate is 98.51%, and breaking rate is 0.9%. A prototype is made with the optimal cylinder combination (axial flow single cylinder), performance tests about it are carried out, the picking rate and the breaking rate of the prototype are 98.5% and 0.89%. |
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