Simulation Analysis Of Driving Performance Of Small Crawler Chassis In Facility Farm

Facilities farms in hilly areas of southern Anhui are characterized by many slopes,wide trenches and sticky roads,which seriously affect the efficiency of agricultural product transfer vehicles.At present,the research and development mode of agricultural product transfer vehicle chassis is mainly one machine for one use,and the real vehicle test cost is high and the efficiency is low,which can not meet the actual work needs of the rapidly changing farm.Aiming at the design requirements of small crawler chassis for agricultural products transfer vehicles in facility farms in hilly areas of southern Anhui,this thesis carries out simulation analysis and research on the driving performance of small crawler chassis in facility farms.The main research contents are as follows :(1)Design of small crawler chassis test platform for facility farm.According to the terrain characteristics of the facility farm and the actual work requirements of the chassis,the design index of the test platform is proposed.Combined with the index,the main parameters,driving resistance and power system of the crawler chassis driving device are calculated and selected.The static analysis of the frame and parts is carried out by ANSYS,and the strength and stiffness verification of the chassis structure and the trial production of the real vehicle are completed.(2)Theoretical analysis of tracked chassis driving stability.Aiming at the typical road conditions such as straight line,steering,ramp and obstacle crossing in the actual driving operation of the tracked chassis,the theoretical analysis and research on the driving stability of the tracked chassis under the limit state of typical road conditions are carried out.The calculation results show that the limit width of the tracked chassis is 644 mm,the limit height of the vertical obstacle is 308 mm,the limit overturning angles of longitudinal uphill and downhill driving on the ramp are 61.7 ° and 60.5 ° respectively,and the limit overturning angle of lateral driving on the ramp is 47.2 °.(3)Establishment and verification of multi-body dynamics model of track chassis.The multi-body dynamics model of the tracked chassis is established by using Recur Dyn simulation software.The real vehicle test results of the chassis on hard and soft roads are compared with the simulation results to verify the accuracy of the model.The comparison results show that although there are deviations in the average speed,centroid position offset and driving wheel torque of the chassis running in a straight line on hard and soft roads,the relative errors are not more than 5 %.The two data are highly consistent.This model can be used to reflect the dynamic characteristics of the tracked chassis.(4)Simulation analysis of tracked chassis driving performance.In the simulation software Recur Dyn,the driving stability of the tracked chassis under typical driving conditions such as straight line,steering,ramp and obstacle crossing is studied by changing the main influencing factors such as soil parameters,driving speed and ramp angle.The simulation results show that the tracked chassis can run stably on the sand and hard road slopes with a slope angle of 25 °,but the slope angle should be less than 20 ° when the clay road is stable.The limit height of crossing on hard and clay pavement is 311 mm and 345 mm respectively,and the limit width of crossing is 667 mm and 625 mm respectively.The driving stability is better when the hard road is turned,but the lateral stability of the straight road is worse than that of the sand and clay road.Therefore,this design can meet the design requirements of the small crawler chassis test platform for facility farms.