Design And Research Of Caragana Intelligent Harvesting Equipment

Desertification is a major environmental problem facing our country,and it is also a serious problem of social and economic sustainable development.Combating desertification and carrying out sustainable land management are currently China’s strategic tasks in the ecological field.An effective way to solve the problem of desertification is to plant Caragana,which is drought-resistant and sand-protecting.Affected by its own growth characteristics,Caragana must flatten stubble every 3 to 5 years,simultaneously,the height of the stubble should be balanced,and the stubble section should be smooth.At this stage,most of the shrub harvesting machinery existed in the domestic and foreign markets are only suitable for working on flat land,and can’t adapt to the shallow mountain and hilly landforms of the arid and semi-arid areas in Northwest of China.Therefore,designing Caragana intelligent harvesting equipment that is suitable for shallow mountain and hilly areas is one of the research focuses on solving our country’s mechanized harvesting.The subject of this paper is based on key research and development projects in Ningxia.The main research content and conclusions are as follows:(1)The biological characteristics of Caragana,the theory of wood cutting at home and abroad,and the research status of shrubs and Caragana harvesting machinery are summarized.Combining actual working conditions,agronomic requirements and technical requirements of Caragana,the overall plan of the Caragana intelligent harvesting equipment are completed.The multi-disc cutter and the movable platform form a 4-degree-of-freedom mechanism to realize terrain adaptive cutting.A height-adjustable reel is set to cooperate with multiple rotating rods and spread reels to realize Caragana plant’s reeling,conveying and laying.(2)The whole machine structure of the equipment is determined,and the key components including the cutting device,the movable platform,the conveying and laying device and the reeling device are designed and researched.The cutting speed,cutter feed speed,reel installation height and other parameter ranges are determined,and the relevant components are selected.(3)Static analysis based on ANSYS/Workbench is carried out on the circular saw blade and frame of the equipment.Their stress,strain and deformation distribution under different stress conditions are summarized,and it is determined that they could meet the requirements of working reliability.Modal analysis based on ANSYS/Workbench is carried out on the circular saw blade and frame of the equipment.Their first 20 natural frequencies and mode shapes are obtained.Compared with the external excitation frequency of the equipment,it is determined that resonance failure would not happen.The positive kinematics analysis of the movable platform and the cutting device is carried out,and the positive kinematics model is obtained.Feasibility of structural movement is verified in the ADAMS software.Based on ANSYS/LS-DYNA,a finite element model of a circular saw blade cutting a single Caragana stalk is established,and the dynamic analysis is carried out.The regular pattern of the cutting force changing with time during the cutting process is obtained.Further investigation can reach conclusion which reveals the cutting force varies with the speed of the saw blade,the forward speed of the equipment and the diameter of the stalk of Caragana.(4)Based on the axiomatic theory,the hydraulic system of the equipment is conceptually designed,and the independence of the designing process is determined.Combining with the structural design and selection results of the equipment’s components,each circuit in the hydraulic system is designed and integrated into the overall hydraulic system.Calculate the flow of each circuit and select the corresponding hydraulic pump,diesel engine and hydraulic valve based on this.(5)Based on the AMESim simulation software,the hydraulic system model of the equipment is established,and each circuit is simulated to obtain the dynamic response characteristics of each hydraulic actuator.Comparing the response curves of the cutting motor under different loads verifies the rationality of the system function.