摘要
为了使有液压机械无级变速器的中小型拖拉机获得更高的燃油经济性,使得拖拉机在任意工况下都能工作在整机经济性最佳的工作点上,该研究结合一种行星比连续可变的液压机械无级变速传动系统(hydro-mechanical continuously variable transmission,HMCVT),提出以发动机燃油消耗率ge与HMCVT传动效率ηb之比为拖拉机整机经济性目标函数,在考虑发动机转速、转矩和HMCVT变速传动系统中变量泵排量比调节的基础上,加入HMCVT变速传动系统中牵引式行星排的行星比这一辅助变量,对发动机工作点和HMCVT工作点进行多参数调节。然后采用参数循环算法对多参数调节中的控制参数进行优化,得到任意负载和目标车速下的最佳发动机转速、转矩和最佳HMCVT变量泵排量比和牵引式行星排的行星比。随后分析了不同作业车速下牵引式行星排的行星比对拖拉机整机经济性的影响,得到低、中、高3种车速工况下的最佳行星比及排量比,最后从HMCVT的传动效率和变速比两个方面验证多参数调控效果。结果表明,具有排量比和行星比双参数可调的液压机械无级变速传动系统能满足中小型拖拉机的犁耕作业,与国标相比牵引式行星排行星比的加入使拖拉机的燃油消耗率降低29.86%;行星比越大,拖拉机整机比油耗越低。该研究提出的多参数控制策略能够保证拖拉机在宽速比和高效率区域下工作,且易于实时调控,研究结果可为推动无级变速拖拉机变速器开发应用和进一步改善拖拉机动力性与燃油经济性提供理论参考。
Fuel economy has been the basic requirement of tractor operation in recent years.This study aims to improve the fuel economy of small and medium-sized tractors with hydro-mechanical continuously variable transmission(HMCVT)in modern agriculture.The continuous variable planetary ratio of a single planetary row was also combined to run at the working point with the best economy of the whole machine under any load conditions.The parameter of continuous variable planetary ratio was then considered to further improve the control strategy of HMCVT fuel economy.Firstly,the optimal fuel economy index of the tractor was analyzed during this time.The ratio of engine fuel consumption rate ge to HMCVT efficiency of transmissionηb was proposed as the economic objective function of the tractor.The effective fuel consumption rate of the BM58G diesel engine was combined to explore the influencing factors of transmission efficiency of planetary ratio continuously variable HMCVT.In addition to the three basic parameters of engine speed,torque and displacement ratio of the variable pump,the planetary ratio of the planetary row also showed a certain influence on the economy of the tractor.Then,the evaluation index of the tractor economy was determined to combine with the operation characteristics of small and mediumsized tractors.A multi-parameter stepless speed control was formulated with the engine speed,torque,displacement ratio of the variable pump of the HMCVT variable speed transmission system and the planetary ratio of traction planetary row as the control parameters.The control flow was then elaborated on in detail.At the same time,the small and medium-sized HMCVT tractor with the continuously variable planetary ratio was taken as the research object.The control parameters were calculated in the multi-parameter adjustment using Matlab software and the parameter cycle algorithm.The optimal combination was obtained,including the optimal engine speed,torque,and HMCVT variable pump displacement ratio and the planetary ratio of
作者
梁丽
李青涛
谭芸颖
杨兆虎
LIANG Li;LI Qingtao;TAN Yunying;YANG Zhaohu(School of Mechanical Engineering,Xihua University,Chengdu 610039,China;Institute of Modern Agricultural Equipment,Xihua University,Chengdu 610039,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2023年第10期48-55,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(51905447)。
关键词
拖拉机
优化
燃油经济性
液压机械无级变速器
参数循环算法
tractor
optimization
fuel economy
hydro-mechanical continuously variable transmission
parameter cycle algorithm
