安全距离和成像尺寸约束的超大视场红外系统车载应用关键参数论证

在现有车载辅助驾驶系统中，可见光成像系统难以有效应用于夜晚、雨、雾、霾等低照度不良天气。红外成像系统有效克服了上述不足，但传统车载红外系统存在视场角小、视野盲区大的缺点。研究了超大视场红外系统的车载辅助驾驶应用，提出了基于安全距离和成像尺寸联合约束的超大视场红外系统关键参数论证方法。通过分析等距投影成像规律，建立了超大视场红外系统车载应用的安全距离约束模型和成像尺寸约束模型，以极限速度对应的探测最近距离和二维Johnson准则约束下的“发现”最远距离来验证超大视场红外车载系统的可行性，计算了视场角等关键参数。经过理论论证和分析，超大视场红外车载系统的镜头焦距/像元尺寸范围需在276.1 521.3]范围之内。通过开展系统试验，设计了水平视场角为140°的超大视场红外成像系统，满足了对人的发现距离大于130 m的要求，进而可用于车辆辅助驾驶。

Key Parameters Demonstration for Ultra-Field Infrared System in Vehicle Application Based on Safety Distance and Imaging Size

In the existing vehicle assisted driving systems, a visible imaging system is difficult to be effectively applied to night, rain, fog, haze and other bad weather conditions with low illumination. An infrared imaging system can effectively overcome the above shortcomings, but the traditional vehicle infrared system has the shortcomings of a small field of view and large blind area. The vehicle application of the ultra-field infrared system is studied in this paper, and a demonstration method of key parameters is proposed for ultra-field infrared system application by utilizing the joint constraints based on safe distance and imaging size. Specifically, the isometric projection imaging law is firstly analyzed; then, the constraint models of safety distance and imaging size are established. Finally, its feasibility is verified by the nearest detection distance corresponding to the limit speed and the longest discovery distance under the constraint of the two-dimensional Johnson criterion, and its key parameters are calculated. The ratio of the lens focal length to pixel size range of the ultra-field infrared vehicle mounted system shall be within the range of276.1 521.3] through theoretical demonstration and analysis. The system experiments designed the ultra-field infrared imaging system with a horizontal field angle of 140° is designed in the system experiments. The detection distance of the infrared imaging system is more than 130 m, which can meet the requirement of discovery distance for auxiliary driving.