本文研究的主要内容是利用“飞思卡尔公司”的16位单片机 MC9S12DG128,设计能在特定跑道上寻迹行驶的智能小车。分硬件和软件两部分进行设计。硬件主要有:红外传感器数据采集模块、直流电机 PWM 波驱动模块、单片机控制模块。软件主要有:寻迹程序和速度 PID 控制程序。 The main content of this paper is to design MC9S12DG128, a 16-bit microcontroller based on Freescale, to design an intelligent trolley that can track a specific runway. Sub-hardware and software designed in two parts. Hardware mainly include: infrared sensor data acquisition module, DC motor PWM wave drive module, microcontroller control module. The software mainly includes: Tracing procedure and speed PID control procedure.