采用滑转率-阻力区间划分法的拖拉机双流传动系统调速控制  

Speed regulation control of the dual-flow transmission system for a tractorusing slip rate-resistance interval division

作　　者：夏光 夏岩 唐希雯 高军 汪韶杰 孙保群 Xia Guang;Xia Yan;Tang Xiwen;Gao Jun;Wang Shaojie;Sun Baoqun(Institute of Automotive Engineering,Hefei University of Technology,Hefei 230009,China;College of Electronic Engineering,National University of Defense Technology,Hefei 230009,China;School of Automotive and Traffic Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学汽车工程技术研究院,合肥230009 [2]国防科技大学电子对抗学院,合肥230009 [3]合肥工业大学汽车与交通工程学院,合肥230009

出　　处：《农业工程学报》2021年第3期47-55,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(51875151);科技部重点研发计划项目(2016YFD0700604、2016YFD0700605);安徽省重大专项项目(18030701193)。

摘　　要：为解决拖拉机作业过程中因作业阻力波动而导致生产效率降低的问题,该研究以自主开发设计的液压机械无级变速器(Hydraulic Mechanical Continuously Variable Transmission, HMCVT)为研究对象,通过对滑转率区间划分确定了滑转率控制和车速控制的优先级;通过对作业阻力范围划分确定了适合当前阻力状态下的HMCVT传动模式,并以拖拉机最高生产效率为目标制定了HMCVT系统在液压机械传动(Hydraulic Mechanical Transmission,HMT)和静液压传动(Hydrostatic Transmission,HST)模式下的变速规律,确定了HMT和HST传动模式下的排量比调节曲面。针对油压波动会影响液压泵排量调节精度的问题,提出了基于前馈补偿的滑模控制算法,搭建了HMCVT传动系统和调速策略模型。结果表明,提出的基于滑转率-阻力区间划分的调速控制策略能够在负载或路面条件发生变化时,将驱动轮滑转率约束在容许滑转率区间内;本文制定的变速规律相比于传统动力性变速规律能使拖拉机车速和加速度分别由5.06km/h和0.05 m/s^(2)提升至5.3 km/h和0.15 m/s^(2),加速度能力更强,可保证拖拉机的生产效率,提高拖拉机对复杂多变作业环境的适应性。Operation resistance of a tractor fluctuates frequently when working in the farmland,due to the complex field environment and terrain differences.As such,the resulting change of speed cannot guarantee the operation efficiency of the tractor.Taking a newly developed Hydraulic Mechanical Continuously Variable Transmission(HMCVT)as the research object,this study introduced the principle of transmission,mechanical structure and transmission efficiency in a Hydraulic Mechanical Transmission(HMT)transmission mode.The slip rate was divided into different intervals according to the traction efficiency curve of the tractor.In different intervals of slip rate,the first priority was to ensure the highest production efficiency and the traffic ability of a tractor.Specifically,if the slip rate of driving wheel was within the allowable range of slip rate,the first priority was to ensure the production efficiency of the tractor,where the strategy of variable speed control was implemented;if the slip rate of driving wheel exceeded the maximum allowable slip rate,the first priority was to ensure the traffic ability of a tractor,where the control strategy of slip rate was implemented,in order to avoid the serious consequences,particularly that the vehicle cannot move due to excessive slip of driving wheel.In speed control,the internal division of operation resistance was used to determine the transmission mode of HMCVT system suitable for the current resistance state.Taking the maximum production efficiency of tractor as the goal,the law of speed change was optimized to determine the adjustment surface of displacement ratio for the HMCVT system in HMT and hydrostatic transmission(HST)mode.A feedforward compensation was designed using the sliding mode control algorithm,in order to deal with the constant change of pump displacement.The reason was that the fluctuation of oil pressure caused the variation in the inclination angle of variable pump in the reverse direction.The working oil pressure inevitably fluctuated in the pump-contr

关 键 词：农业机械 拖拉机 液压机械传动 滑转率-阻力区间 最高生产率 

分 类 号：S232.3[农业科学—农业机械化工程]