文档介绍：华中科技大学
硕士学位论文
同步换档电动自行车控制器设计与实现
姓名:王闻宇
申请学位级别:硕士
专业:控制理论与控制工程
指导教师:沈安文
20080604
摘要
作为一种新兴的交通工具,近几年电动自行车因其生产和使用上的诸多优点而飞
速发展。但目前电动自行车普遍存在力矩不足、蓄电池寿命低、电机退磁、控制器故
障率高等问题,这些问题正在成为电动自行车行业发展的瓶颈。本文提出了运用机械
换档技术改善电机工作环境的思想,是对提升电动自行车性能、开发新型驱动方式的
一次具有重要意义的探索。
首先,找到了影响电动自行车性能的关键问题——大电流,并将其归结为转矩与
转速之间的矛盾。为实现转矩与转速的平衡,设计了同步换档机构。根据电动车自行
车安装换档机构后的驱动要求,分析了换档机构和直流无刷电机控制中可能遇到的噪
音抑制、回馈制动、同步预估、换档策略等几个关键问题,并通过分析直流无刷电动
机的动态、稳态特性提出了相应的解决方法。
然后,利用 Matlab/Simulink 仿真软件在理论分析和行驶数据的基础上搭建了车
辆与道路模型,通过不同行驶条件下仿真结果验证了换档电动车的优秀性能,并证明
能有效解决上面提到的几个关键问题。
最后,在以 ATMEGA48 单片机为核心的硬件平台上实现了直流无刷电机驱动与
换档的相关动作,证明了换档方案的整体可行性。

关键词:电动自行车同步换档直流无刷电机
I
Abstract
As a new and popular vehicle, electric bicycle has been fast developing thanks to its
convenience in both producing and using. However it's also bothered with problems such
as low torque, low battery lifespan, motor ization, and high controller fault rate,
which could be major drawbacks to its further development. Gear shifting is proposed to
improve the working condition of the motor. The study is a significant effort on improving
the performance and developing a new driving mode for electric bicycles.
First, large current is found key to the problems, and it is caused by the
contradiction between speed and torque. A Gear box is designed allowing for both speed
and torque. Possible problems in controlling the gear box and motor such as noise
reduction, energy regeneration, synchronization prediction, and shifting strategy are
studied, solutions of which are proposed through analyzing of the dynamic and static
model of the BLDC motor.
Second, mathematical models of the bicycle and road are built based on both
calculation and experiment. A simulation is performed to prove the outstanding
performance of the gear-shifting electric bicycles, as well as the effectiveness of the
controlling algorithm.
Finally, the BLDC motor driving and gear shifting actions are performed on an
electric