基于双重目标的液力变矩器闭锁过程控制策略研究

A Research on Lock-up Process Control Strategy for Torque Converter Based on Dual Objectives

为兼顾液力变矩器闭锁过程冲击度和滑摩功的要求,建立了闭锁过程整车动力学模型,并推导了闭锁过程冲击度、滑摩时间和滑摩功等公式。接着以某重型车辆为例,通过仿真得到了发动机转速按等斜率下降时的闭锁过程冲击度曲线。结果表明,冲击度远小于标准限值。通过计算分析得出发动机转速按等斜率下降闭锁过程中闭锁离合器压力系数的合理取值范围在1. 05～1. 2之间,滑摩时间控制在1s左右。根据仿真结果,提出了基于发动机转速目标轨迹的闭锁过程控制策略,并通过实车试验验证了其可行性。本研究为兼顾冲击度和滑摩功要求的离合器接合控制提供了一种有效的策略。

In order to take into account the requirements of both jerk and slipping work of torque converter in lock-up process,the vehicle dynamics model in torque converter lock-up process is set up,with the formulae of jerk,slip time and slipping work in lock-up process derived.Then taking a heavy-duty vehicle as an example,a simulation is conducted to obtain the jerk curve in a lock-up process with engine running in a constant deceleration condition.The results show that the jerk is much smaller than the standard limits and it is found by calculation and analysis that in the lock-up process with the engine decelerating with a constant rate,the reasonable values of clutch pressure coefficient are in a range of 1.05 and 1.2 with a slipping time of around 1s.Finally according to the results of simulation,a control strategy for lock-up process is put forward based on the target trajectory of engine speed,with its feasibility verified by real vehicle test.This study provides an effective strategy for clutch engagement control with concurrently considering the requirements of both jerk and slipping work.