A Study On Walking Stability Of Self-Propelled Elevated Sprayer

Maize has become the most-planted food crop in China. However, the severity of maize diseases and pest insects of maize is higher and higher under the influence of climate change and changes in cropping system, farming structure, cultivated varieties, agricultural eco-environment and mode of production. The average height of maize is 2.1meters in big trumpet period when is the best time to spray insecticide. Therefore, high-clearance sprayer is needed for spraying insecticide during mid-late maturity growth period of maize.Since high-clearance sprayers have a high centre of gravity with heavy load and usually work in a complicated environment, its walking stability is undoubtedly vital. Based on the review of studies on autonomous high-clearance sprayer and vehicle stability home and abroad, this study focuses on the design and research on self-propelled high-clearance sprayers for maize planting. With the adoption of classic mechanic analysis, finite element analysis and simulation experiment, this paper has approached in the following four aspects:(1) Based on the analysis and design of whole machine and key components structures, a self-propelled high-clearance sprayer is trial-produced.(2) With the application of classic theories of mechanics, the walking stability of high-clearance sprayer has been analyzed with longitudinal and lateral overturning and translation angles of slope derived, the formula of evaluation index on stability is further calculated. Through experiments, the parameters and the precise location of gravity center of the high-clearance sprayer have been obtained; besides, quantitative stability evaluation indexes have been deduced through the formula based on stability theory.(3) Founded on the finite element analysis of the rack which influences machine stability, the cloud pictures of stress and strain have been produced. The result shows the strength and stiffness of the rack can meet the requirements. In terms of the vibration and noise generated in operation, a modal analysis of the rack has been done. What the results indicate is that the engine in operation will not cause resonance of the frame. A three-dimensional model has been carried out for the whole machine, and a dynamic simulation of the sprayer slipping in longitudinal and transverse slope has been achieved through the simplification of model use. The results verify the accuracy of the longitudinal slip angle and lateral slip angle.(4) Conduct field trials to test the two do not have a vertical slip ramp slope angles within quantify indicators in the evaluation.