二维MAX-DOAS仪扫描控制系统设计

Design of scanning control system for two-dimensional MAX-DOAS instrument

为了实现二维多轴差分吸收光谱(MAX-DOAS)仪的扫描需求,以两相步进电机驱动芯片TMC261为核心,基于STM32微处理器和光电编码器,设计了棱镜扫描控制系统。分析了二维MAX-DOAS外置棱镜对转动精度和分辨率的需求,从控制系统结构设计、具体实现过程两个方面阐述了系统方案,并进行测量实验来评估实际效果。结果表明棱镜的转动步进角细分倍数在0~256范围内可调。扫描分辨率最多可达1.8°/256,位置精度误差低于5%,步距角精度误差绝对值低于8%。所设计扫描控制系统在光学仪器中具有广泛应用前景。

In order to realize the scanning requirements of the two-dimensional multi-axis differential absorption spectroscopy(MAX-DOAS) instrument,a control system for prism scanning is designed based on STM32 microprocessor and photoelectric encoder with the two-phase stepper motor driver chip TMC261 as the core.The requirements for rotational accuracy and resolution of two-dimensional MAX-DOAS external prism are analyzed,and then the system scheme is expounded from the two aspects of control system structure design and concrete implementation process.Measurement experiments are carried out to evaluate the actual effect of the designed system.Results show that the subdivision of the rotational stepping angle of the prism can be adjusted within the range from 0 to 256,the scanning resolution is up to 1.8°/256,the position accuracy error is less than 5%,and the absolute value of step angle accuracy error is less than 8%.It indicates that the designed scanning control system has a broad application prospect in optical instruments.