Study On The Dynamic Modeling And Simulation Of Driving Stability Of High-gap Sprayer

Self propelled high-gap sprayer is widely used in the field of corn and other high bar crops on the late stage of pest control.However,because of the complexity of the field environment and the uneven road,especially under the condition of road excitation,the liquid sloshing of the non full loading box is aggravated,and the riding comfort,especially the driving stability,is greatly affected.Moreover,the driving stability of the high-gap sprayer is very important for ensuring the safety of the operation and improving the efficiency of the operation.Therefore,referring to the study of the stability problem of conventional vehicles and combining the special structure of the high-gap sprayer and the special operating conditions,it is of practical significance to study the driving stability of the high-gap sprayer,such as the lateral stability and ride comfort,for its driving safety and stability.The multi-body dynamics model of the high-gap sprayer is established,and the matching between the wheelbase and wheelbase of the highland gap sprayer is optimized.A liquid sloshing model of the tank and a fluid solid coupling model are established to optimize the ride comfort of the highland gap sprayer and match the optimal suspension parameters to improve the ride comfort of the high-gap sprayer.As follows:(1)Determine the overall structure design plan of the high-gap sprayer,establish the three-dimensional model and virtual prototype model of the main parts of the high-gap sprayer;establish the random pavement model suitable for the field operation of the high-gap sprayer based on the principle of Adams pavement generation and the principle of harmonic superposition;and establish the multi-body dynamics model for the driving stability of the high-gap sprayer.(2)Through the simulation analysis of the high-gap sprayer with different track and wheelbase combination,the optimal wheelset and wheelbase combination of the high-gap sprayer were determined under different operating speeds and different liquid filled ratios.(3)Based on the random acceleration process of the liquid forced sloshing in the tank,the acceleration excitation is studied,the random acceleration excitation function is compiled,and the acceleration function of the sine random excitation is fitted;the user-defined function of monitoring the liquid mass center in the liquid sloshing process is compiled.Based on the two kinds of acceleration excitation,the process of liquid forced sloshing is studied,and the correctness of the model is obtained.The sloshing intensity and the position change of liquid mass center are mainly affected by the lateral acceleration and longitudinal acceleration,but less by the vertical acceleration.(4)On the basis of the forced oscillation of the liquid in the medicine box,a fluid solid coupling model of the high-gap sprayer was built.The root mean square value of the vertical acceleration of the cockpit seat of the high-gap sprayer and the root mean square value of the lateral acceleration of the liquid core and the root mean square value of the longitudinal acceleration were minimized as the optimization objective,and the simulation test was carried out to get the biggest influence factors on the three targets respectively.The optimal suspension parameters are obtained by optimization.