电动汽车两挡I-AMT离合器半结合点自学习算法研究

Self-Learning Control Strategy for Two-Speed I-AMT Clutch Kiss-Point Identification of Electric Vehicles

摘要:

两挡电控机械自动变速器 （automatic mechanical transmission， AMT）可以优化电动汽车的驱动电机工作区间，改善整车的动力性和经济性，但在工作过程中，离合器的半结合点准确辨识对换挡性能影响很大。当离合器摩擦片磨损或膜片弹簧疲劳状态下，离合器实际工作位置发生偏移，需要通过自学习方式来准确辨识离合器半结合点位置，以保证变速器高质量换挡控制性能。以一种新型的电动汽车无动力中断两挡变速器I-AMT （Inverse AMT）为研究对象，针对其干式离合器磨损后半结合点位置发生变化等问题，提出一种离合器半结合点位置自学习策略，使得在离合器缓慢分离的同时，通过检测与离合器主动端相连的驱动电机转速编码器变化趋势，实现离合器半结合点位置准确辨识。试验表明，在离合器存在磨损的情况下，该策略能够准确识别离合器半结合点位置，从而自适应调整变速器工作状态，以保证I-AMT高质量无动力中断换挡。

Abstract:

Two gear AMT （automatic mechanical transmission） can optimize the working range of drive motor and thus improve the drivability and economy of the electric vehicles. However， in the working process， the accurate identification of clutch kiss-point has a great impact on the gear shift performance. Once the clutch friction plate is worn or the diaphragm spring is tired， the actual working position of the clutch may offset correspondingly. Therefore， it is necessary to identify the position of the clutch kiss-point accurately through self-learning so as to ensure the high-quality shift control performance of the transmission. This paper takes a new type of non-torque interruption two-speed transmission I-AMT （Inverse AMT） of electric vehicle as the research object， aiming at the problems such as the change of the position of the clutch kiss-point after the wear， a self-learning strategy for the position identification is proposed. When the clutch is slowly separated， the accurate position identification of the clutch half joint point is realized， by detecting the change trend of the speed encoder of the driving motor connected to the clutch driving plate. The test shows that under the scenario that the clutch is worn， the proposed strategy can accurately identify the position of the clutch kiss-point so as to adaptively adjust the working state of the transmission， thus ensuring the high-quality non-power interruption shift of I-AMT.