基于液压机械无级变速的拖拉机起步预测控制

Predictive Control of Tractor Starting Based on Hydro-mechanical Continuously Variable Transmission

为提高配备液压机械无级变速器(Hydro-Mechanical Continuously Variable Transmission,HMCVT)的拖拉机起步性能,提出了一种基于排量预测调节的液压机械无级变速拖拉机起步控制方法。通过分析HMCVT工作原理及其排量调节机构工作特性,将拖拉机起步过程进行3阶段划分,并以减小起步时间和起步冲击度为目标,建立了基于模型预测控制的拖拉机起步过程排量控制策略。仿真结果表明:与未采用基于排量预测调节的起步控制方法相比,液压机械无级变速拖拉机起步时间缩短了8%,起步最大冲击度减小了32.6%,对HCMCVT拖拉机起步过程有较好的控制效果,起步性能得到较大提高。

In order to improve the starting performance of the tractor equipped with hydro-mechanical continuously variable transmission,a starting control method based on displacement prediction adjustment was proposed.By analyzing the working principle of HMCVT and the working characteristics of the displacement regulating mechanism,the tractor start process is divided into three stages,in order to reduce the starting time and the starting impact degree,the control strategy of the starting process displacement control of the tractor based on the model prediction control is established.The Simulation results indicate that compared with not using the model predictive control method,The starting time of hydraulic mechanical infinitely variable speed tractor was shortened by 8%,the maximum degree of jerk is reduced by 32.6%,which has better control effect on the starting process of the tractor,and the starting performance is greatly improved.