| Water chestnut is an aquatic vegetable with economic and nutritional value,and with an annual production of around 1.4 million tones in China,it is one of the country’s important cash crops.Water chestnut is an easy-to-grow,high-yielding and difficult-toharvest crop.At present,the traditional manual digging method is still used in China,but this method is labour intensive,inefficient and costly.Therefore,the aim of this project is to develop a water chestnut digger to improve the efficiency and effectiveness of mechanized water chestnut harvesting and to bring more convenience to water chestnut growers.The key research elements of this paper include.(1)After detailed fieldwork and research,three different water chestnut harvesters were identified and their advantages and shortcomings were carefully compared according to the requirements of the project,and the water chestnut digger in Option 1was finally identified as the best harvesting solution.Once the harvesting solution was selected,the key components were designed and selected for design accordingly.After the machine had been processed,field trials were conducted to test the reliability and stability of the developed water chestnut digger in the field and to identify any problems with the prototype in time to provide important reference for the later improvement and Optimization of the prototype.(2)Improved design and simulation analysis of the water chestnut excavator.The design of the water chestnut excavator was improved according to the problems that appeared in the field test,including the improvement of the actuator arrangement,digging shovel and linear motion parts of the machine;the topology optimization of the key parts of the water chestnut excavator was carried out by Opti Struct software,and the optimal structural form was obtained.ANSYS simulation software was used to simulate and calculate the structural strength of the water chestnut excavator for two hazardous working conditions,and the results showed that the water chestnut excavator meets the structural strength requirements and there is more room for lightweighting in some structures;the Response Surface Optimization module in ANSYS Workbench was used to carry out the structure with a large margin of stiffness and strength The simulation results show that the mass of the structure after dimensional optimization is reduced by29.5% compared with that before optimization,which shows that the application of response surface optimization in structural dimensional analysis can not only meet the strength requirements of the parts,but also achieve the goal of lightweight.(3)ADAMS-based simulation analysis of water chestnut excavator dynamics.After establishing the dynamics model of water chestnut excavator multi-rigid body system in ADAMS software,the dynamics simulation analysis of water chestnut excavator was carried out by using ADAMS software,and the motion trajectory of its hydraulic cylinder was planned according to the action of water chestnut excavator digging water chestnut,and the motion displacement and force of each hydraulic cylinder was analyzed.The results of the analysis provide relevant parameters for the design of the hydraulic control system,and also provide a theoretical basis for the fabrication of the physical prototype of the multi-rigid system.(4)Design and simulation analysis of the hydraulic control system of water chestnut excavator based on AMESim.On the basis of the traditional mini excavator hydraulic system,the hydraulic system is improved and designed by adding a load-sensitive system to achieve load pressure following,reduce overflow loss and improve system efficiency.The simulation model based on PID hydraulic control system was then established and simulated in AMESim hydraulic simulation software.The simulation results show that the hydraulic control system achieves accurate control of the motion trajectory of digging,turning and pushing actions,which verifies the reasonableness and effectiveness of the hydraulic control system design. |
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