Prediction Model and Experiment on Tractive Performance of Four-wheel Drive Tractor

The existing tractor traction performance prediction model does not include the influence of front and rear wheel different performance, load transfer and uncoordinated front and rear axle movements on the travel reduction ratio and motion resistance ratio, resulting in the low accuracy of field traction performance prediction for four-wheel drive tractors. Starting from the driving characteristics and load characteristics of agricultural tires, and soil-tire driving model and front and rear tire load model were established, including axle load transfer respectively by introducing wheel numeric and mobility number; on the basis of traction force analysis, the prediction models of travel reduction ratio and motion resistance ratio for the whole machine were established respectively considering the influence of actual front and rear axle motion uncoordination on the overall chassis operation. The traction performance prediction model for four-wheel drive tractor containing tire specifications, soil characteristics, uncoordinated front and rear axle motion characteristics of the whole machine, and transmission efficiency was derived. The prediction algorithm and process were designed based on the two-dimensional iterative method to solve the problem arising from the multivariate and nonlinearity of the model; an example analysis and application were carried out by using the research method; a field traction test was designed and carried out to verify the validity of the prediction model, and the results showed that the errors of the simulated values in the maximum traction force and the traction force corresponding to the characteristic slip rate were 1.41% and 1. 74%, respectively, and the error in rolling resistance was 0. 64%, which was a large improvement in accuracy over the control group and a small overall error. © 2023 Chinese Society of Agricultural Machinery. All rights reserved.