| Sugarcane is an agricultural crop with high economic value,which is widely planted in China,but at present,the level of full mechanization of sugarcane production in China is still relatively backward.Sugarcane harvester is an important part in realizing the full mechanization of sugarcane production.An efficient sugarcane harvester can diminish the labor intensity of laborers and enhance the quality of the harvesting.Hydraulic system is the core transmission device of sugarcane harvester,and improving the dynamic quality of hydraulic system has become an important direction for upgrading agricultural equipment.In this dissertation,a hydraulic system is devised for a sugarcane harvester,and the dynamic characteristics of the hydraulic system are investigated.The following research contents were mainly accomplished:1.The basic structure and working process of the sugarcane harvester were discussed,the schematic diagram of the hydraulic system of the sugarcane harvester was designed,the composition and working principle of the hydraulic system of the sugarcane harvester were analyzed,the primary hydraulic components were calculated and chosen and the calibration of the hydraulic system was completed.2.AMESim,a computer simulation software,was employed to create a simulation model of the hydraulic system of the sugarcane harvester,and the simulation of the working and travel hydraulic system of the sugarcane harvester was conducted,and the dynamic response of each actuating element was analyzed.3.According to the idea of centralized parameter modeling of hydraulic system based on the node cavity method and the working principle of components,the mathematical models of hydraulic motor,direct-acting relief valve,variable hydraulic pump,three-position four-way reverse valve and hydraulic cavity in the hydraulic system of sugarcane harvester cutting shoots were established.4.A simulation model based on the mathematical model of hydraulic components was built in MATLAB/Simulink and the accuracy of the built mathematical model was validated;Utilizing the node cavity method,a Simulink simulation model of the cutting shoots hydraulic system of the sugarcane harvester was established,and its correctness was confirmed by comparing it to AMESim simulation results.By changing different component parameters in the Simulink model,the effects of component parameter changes on the dynamic characteristics of the hydraulic system were obtained.5.With the powerful data processing capability of Simulink/MATLAB,the optimization of the relief valve setting pressure in the hydraulic system was completed by using curve fitting and bat algorithm,and the dynamic response of the hydraulic motor under the optimal parameters was acquired,and the results showed that the stability of the optimized hydraulic system was significantly enhanced,which validated the accuracy of the optimization method. |
