中文摘要：

文中所设计的基于AVR单片机的轮胎模具内径测量系统，采用光栅尺和激光测距仪测量模具内径，单片机通过接收上位机的命令控制步进电机改变测量点，同时控制光栅尺数显表进行数据采集实时返回给上位机。上位机将光栅尺数据和激光测距仪数据进行运算后得到模具的内径，测量精度在4μm以内。

英文摘要：

Tire mold inner diameter measuring system the paper design is based on the single chip microcomputer AVR, adopting grating scale and laser displacement sensor measuring mould diameter, SCM changes the measured points by receiving the master machine command and controlling the stepper motor, and controls the grating digital readout that acquires data and sends data to the master machine timely. The master machine gets the mold inner diameter by operating the grating scale data and laser displacement sensor data, and the measurement precision of the system is below 4 μm.