考虑离合器摩擦性能衰减的湿式DCT车辆起步控制研究

建立了考虑离合器摩擦系数变化及离合器性能衰减的湿式双离合变速器（dual clutch transmission，DCT）车辆起步过程动力学模型，以车辆起步过程冲击度、滑摩功和起步滑摩时间为优化目标，采用线性二次型最优控制方法获得了车辆起步过程离合器最优传递转矩。针对离合器摩擦系数变化及离合器性能衰减对车辆起步过程离合器压力控制的影响，提出了一种离合器压力非线性鲁棒控制策略，以实现对离合器最优传递转矩的跟踪。结果表明，所提出的非线性鲁棒控制策略能够在离合器摩擦系数变化的情况下实现对离合器最优传递转矩的有效跟踪，跟踪误差不大于0.02 N·m，且能够适应摩擦性能衰减导致不同寿命阶段摩擦系数的不同变化规律，与比例-积分-微分（proportion-integral-differential，PID）控制策略相比具有更精确的控制效果和更强的鲁棒性。

Starting control of wet DCT vehicle considering clutch friction performance attenuation

A dynamic model of the starting process for a wet dual clutch transmission (DCT) vehicle, reflecting changes in clutch friction coefficient and the attenuation of clutch performance, is established. Taking minimum jerk intensity, friction work and starting sliding time as optimization objectives, the optimal transmission torque of the clutch during the vehicle starting process is determined by using the linear quadratic regulator (LQR). To address the impact of clutch performance attenuation and the variation of clutch friction coefficient with the sliding velocity on clutch pressure control, a nonlinear robust control strategy for clutch pressure is proposed. This strategy is designed to track the optimal transmission torque obtained by LQR. Results show that the proposed strategy can effectively track the optimal transmission torque even under changes in clutch friction coefficient, with an average tracking error of about 0.02 N·m. In comparison with the PID control strategy, it exhibits a more accurate control effect and greater robustness.