基于加速踏板开度补偿的直驱式电动车辆离合起步控制

A clutch start-up mode for direct-drive electric vehicle using accelerator throttle compensation

在刚性紧固连接的轮毂与电机间引入离合器,首先分析一种新型轮毂电机离合系统怠速起步模式的运行特点。针对电动车辆变怠速起步模式难以兼顾车辆起步的舒适感和牵入转矩能力的问题,提出一种考虑踏板开度补偿的离合起步解决方案,重点研究车辆起步时加速度变化率与离合器啮合时刻牵入转矩随开度变化的规律,进而优化离合器接合过程中的开度轨迹,以期平衡起步加速度变化率与离合器啮合时刻牵入转矩的需求。最后,对有、无实施踏板开度补偿的离合起步进行实验对比。结果表明:较之常规的变怠速起步模式,采取加速踏板开度补偿的离合起步策略,在峰值电流相同时,起步冲击度降低了50%;且在未引入额外起步冲击度的情况下,起动承载能力即升速范围一倍于怠速受限的离合起步模式。

Using a clutch mechanism in a rigid connection between the motor and wheel, an idling start-up mode for a novel clutch assembly of wheel drive system is firstly investigated in this paper. Focusing on difficulty in coordinating the driving comfort and torque capacity in the idling start-up mode, an improved solution is proposed by adjusting pedal throttle to torque compensation. Besides, the strategy for the start-up jerk level and the motor torque at clutch lock-up time are fully studied. Further, the method for tracking the pedal throttle during clutch engaging process is optimized, aiming at finding a balance between the demanded motor torque and the jerk level at clutch lock-up time. Finally, experiments are carried out to compare the clutch start mode with or without pedal throttle compensation. In contrast to the traditional idling start-up mode under the same peak current, the results using clutch start-up mode with pedal throttle compensation show that the start-up jerk level is decreased by 50%. Moreover, it confirms that the motor torque at clutch lock-up time and adjustable speed range is increased by one times without bringing extra jerk level, compared with the clutch start-up mode where the idle speed is restricted to its upper value.