Design And Experiment Of Walking Electric Vehicles In Sloping Tea Garden

At present,there is a lack of small transport machinery suitable for the transportation of high mountain steep slope tea gardens,a walking electric vehicles for sloping tea gardens was designed by using agricultural vehicle design,discrete element method simulation analysis and reliability theory based on the research of hilly and mountainous transport vehicles at domestic and foreign.The vehicle walks with one wheel and had strong passing ability in the tea gardens.It solves the problem of “no vehicle available” in tea gardens on high mountain and steep slope,which is of great significance to reduce the working intensity of tea farmers and improve the transportation efficiency of tea gardens.The research contents of the paper are as follows:1)The horticultural parameters of hilly and mountainous tea gardens were measured.The results showed that the planting slope of tea gardens was mostly less than 40°,and the longitudinal slope width was mostly 0.8-1.2 m,which led to the large transport vehicles unable to carry out transport work inside,so it was necessary to develop small transport vehicles.According to the agronomic requirements,the overall size of the sloping gardens walking electric vehicles was designed to be 1500×680×1100 mm.The full load power consumption of the scooter was calculated and the selection of the motor and battery was completed.The mechanical transmission was used to walk and the transmission ratio of the transmission system was designed.The main parameters of the frame are determined,and the static analysis of the frame is carried out by ANSYS Workbench.The stress distribution and displacement distribution of the frame under full load are obtained.2)The wheel-soil interaction in the process of single-wheel vehicle transportation is studied theoretically.Through the force analysis of the wheel-soil contact,the theoretical model of wheel-soil contact is established,and the driving torque,wheel load and traction behavior in the process of wheel-soil contact are analyzed.It is obtained that the wheel structural parameters,sandy loam properties and driving parameters can all affect the passing performance of the wheel on sandy loam ground.3)The discrete element simulation was used to analyze the wheel-soil contact process of the single-wheel vehicle in the tea garden.The Hertz-JKR contact model was established based on the discrete element method,and then the contact parameters were calibrated between the sand soil particles and the particles,and between the soil particles and the tires.Different test schemes were designed for discrete element simulation.Through EDEM simulation,the variation laws of wheel resistance torque,traction force and soil fluctuation rate of wheel-soil contact were obtained.At the same time,the maximum torque of wheel walking was 80.8 N·m,and the maximum torque provided by the deceleration motor was far more than 80.8 N·m,which verified that the selected motor could meet the requirements of transportation.4)The prototype test and tea garden transportation test of walking electric vehicles in slope tea garden were carried out.The maximum driving speed of the vehicles can reach 7km/h,the maximum load capacity is 100 kg,and the maximum climbing degree is 40°,which meet the transportation needs of large slope tea garden.