双离合自动变速汽车坡道挡位优化研究

Study on Slope Gear Optimization for DCT Vehicles

摘要:

为了解决双离合自动变速汽车坡道行驶时采用基本二参数换挡规律引起的换挡循环现象,设计了一种坡道挡位优化策略;首先基于车辆纵向动力学模型,运用拉格朗日插值算法对道路坡度进行实时辨识；进而,利用模糊推理得到坡道换挡因子,从而优化汽车坡道挡位；最后,对提出的挡位优化策略进行仿真与分析;仿真结果表明:该挡位优化策略能够根据所辨识的道路坡度有效地确定汽车挡位,不仅解决了车辆在上坡行驶时的换挡循环现象,同时下坡时能使发动机充分发挥辅助制动作用。

Abstract:

A strategy on gear optimization is designed to solve the problem of shift cycle for the vehicles equipped with Dual-Clutch Transmission, which adopt two-parameter shift schedule when driving on the slope. Firstly, based on the longitudinal vehicle dynamics model, the road slope is estimated in real-time using Lagrange interpolation algorithm. Furthermore, the slope shift factor is established based on fuzzy theory , thus to optimize the vehicles’ gear when driving on the slope. A simulation and analysis is carried out on the proposed gear optimization strategy. The simulation result shows that the gear can be determined effectively by this strategy according to the estimated slope .which not only solved the shift cycle for the vehicles while driving uphill, but also the auxiliary braking can be fully utilized by the engine while driving downhill.