理论换段点下HMCVT换段离合器转矩交接及控制  

Torque handover and control of the HMCVT shift clutches under the theoretical shift condition

作　　者：陆凯[1] 鲁杨[1] 邓晓亭[1] 王琳 赵一荣 鲁植雄[1] Lu Kai;Lu Yang;Deng Xiaoting;Wang Lin;Zhao Yirong;Lu Zhixiong(College of Engineering,Nanjing Agricultural University,Nanjing 210031,China;State Key Laboratory of Power System of Tractor,Luoyang 471039,China)

机构地区：[1]南京农业大学工学院,南京210031 [2]拖拉机动力系统国家重点实验室,洛阳471039

出　　处：《农业工程学报》2022年第19期23-32,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：拖拉机动力系统国家重点实验室开放课题(SKT2022006);国家重点研发计划项目(2016YFD0701103)。

摘　　要：针对液压机械无级变速器在换段过程中的动力中断和换段冲击问题,该研究以三段式液压机械无级变速器第二段切换第三段为例,通过建立动力学模型分析理论换段点下两段位的液压路功率方向变化规律,提出基于液压路功率方向的两阶段换段离合器转矩交接方法,并使用分段函数对两阶段离合器转矩交接轨迹进行优化,通过仿真对转矩交接方法正确性进行了验证。为了实现转矩的跟踪控制,基于终端滑模控制的方法设计了离合器控制器,通过对油压的跟踪控制实现转矩的跟踪控制,通过试验验证了控制器有效性。仿真和试验结果表明:在负载换段过程中,所提换段离合器转矩交接方法能够实现动力的平稳过渡,终端滑模控制器能够实现离合器油压的跟踪控制,从而实现转矩控制。在输入轴转速1 000 r/min,负载700 N·m工况下,使用终端滑模控制器控制两换段离合器进行换段,输出轴转速的波动范围为-20.6~7.4 r/min,输出轴转矩波动范围为-117.4~107.9 N·m,换段过程中最大冲击度为-6.16 m/s3,换段离合器的最大滑摩功为508.45 J,换段过程中无动力中断。该研究可为液压机械段变速器的换段控制提供参考。Hydraulic mechanical continuously variable transmission(HMCVT) has the advantages of low impact, high efficiency and high power, which could suit the requirements of continuously variable transmission for high-power vehicles such as tractors and engineering vehicles. During the HMCVT phase change, the power needs to be transferred from current clutch to target clutch. In this process, the torque of the quantitative motor reverses, which reverses the pressure on the high and low sides of the hydraulic components, resulting in the reverse power of the hydraulic circuit. as a result of which the rotational speed of hydraulic component changes abruptly, causing the fluctuation of output speed as well as vibrations and noises.Aiming at these problems in the process of power shift, a torque handover mechanism of HMCVT clutch under the condition of theoretical shifting segments is proposed based on the dynamic model of HMCVT power shift. For example,HMCVT shifts from HM2 to HM3. When the double clutches of the current range and target range overlapping,torque handover process is divided into two stages for discussion: hydraulic system positive power stage and hydraulic system negative power stage. When the ideal shift timing comes, clutch C3 would be operated. hydraulic system comes to positive power stage, the increase of C3 torque reduces C2 torque and motor torque until the positive power of hydraulic circuit becomes zero when the motor torque decreases to zero. At this stage, the torque transfer characteristics of clutch depend on C3torque. When clutch C2 is detached, the reduction of C2 torque increases C3 torque, so that the motor torque changes from zero to negative, and the hydraulic circuit power transfers negative power from zero. At this stage, the torque transfer characteristics of the clutch depend on C2 torque. So, a piecewise-continuous function is established with torque change rate and torque change acceleration as parameters to optimize the torque handover trajectory of the two stages. The clutch contr

关 键 词：离合器 转矩控制 滑模控制 液压机械无级变速器 换段质量 

分 类 号：TP271.4[自动化与计算机技术—检测技术与自动化装置]