可见/近红外实时成像光谱仪控制系统设计

针对高光谱成像需求,设计了一套可见/近红外实时成像光谱仪。光谱仪基于声光可调谐滤波器(Acousto-Optic Tunable Filter,AOTF)分光器件进行设计,光谱带宽为1.3μm,其中可见光相机工作在400~1000 nm波段,近红外相机工作在1000~1700 nm波段。光谱仪控制系统以现场可编程门阵列(Field Programmable Gate Array,FPGA)为核心处理单元,使用Cameralink接口采集相机数据,使用RS422串口对AOTF进行频率控制,通过AOTF同步信号与相机外触发信号相结合,实现了连续图像与多波长循环采集的一一对应,图像数据最后经过USB3.0接口传输到上位机进行实时显示。经外场测试,光谱仪成像质量良好,系统工作稳定,针对1024×1024分辨率图像,图像实时传输速率最高可达120 frame/s,满足设计要求。在实际工程应用中,该控制系统接口丰富,且可靠性高、灵活性好,具有较强的可扩展性。

Design of a control system for a visible/near-infrared real-time imaging spectrometer

A visible/near-infrared real-time imaging spectrometer is designed for hyperspectral imaging on the basis of an Acousto-Optic Tunable Filter(AOTF). Its operating band range is 1.3 μm, in which the visible light camera works in the 400-1 000 nm band and the near-infrared camera works in 1 000-1 700 nm band. A Field-Programmable Gate Array(FPGA) is used as the core processing unit of the spectrometer control system. The Cameralink interface is used to collect camera data, the AOTF frequency is controlled by the serial port. Through the combination of AOTF synchronization signal and the trigger signal outside the camera, the one-to-one correspondence between a continuous image and multi-wavelength cyclic acquisition is realized. Finally, the image data is transmitted to the upper computer through the USB3.0 interface for realtime display. The field test shows that the imaging quality of the spectrometer is good and the system works stably. For images with a 1 024×1 024 resolution, the real-time transmission rate of the image can reach up to120 frame/s, which meets the design requirements. In practical engineering applications, the control system has a rich interface, high reliability, flexible interface and strong expansibility.