基于改进YOLOv7的低空飞行物目标检测方法

Low Altitude Flying Target Detection Method Based on Improved YOLOv7

目前无人机检测技术应用广泛,但无人机在执行目标检测任务中可能遭遇多种空中障碍物,这些目标具有成像小、像素特征少和相对速度变化快等检测难点,针对此类目标引起的漏检误检问题,提出了一种基于改进YOLOv7算法的低空飞行物目标检测算法。在传统YOLOv7算法的基础上,在Head网络引入SimAM注意力机制,该机制与现有的通道和空间注意力模块相比,同时考虑空间和通道维度信息,且不在原始网络中添加额外参数;在主干网络中结合ConvNeXt网络,提出CvNX模块,降低网络计算量,并保留目标特征;用SIoU-Loss代替原有的CIoU-Loss,提高算法收敛速度;在图像后处理阶段使用SIoU-NMS,减少遮挡导致的目标漏检。在自有低空飞行物数据集上实验结果表明,改进的YOLOv7算法平均精度(Average Precision, AP)达到97.1%,相比YOLOv7算法,平均精度均值(mean Average Precision, mAP)提高了1.7%,且误检、漏检率低,达到了在复杂背景下检测低空飞行物目标的要求。

At present,drone detection technology is widely used,but drones may encounter various aerial obstacles during target detection tasks.These targets have detection difficulties such as small imaging,few pixel features,and fast relative speed changes.To address the problem of missed detection and false detection caused by such targets,a low altitude flying object target detection algorithm based on the improved YOLOv7 algorithm is proposed.Based on the traditional YOLOv7 algorithm,the SimAM attention mechanism is firstly introduced into the Head network.Compared with existing channel and spatial attention modules,this mechanism considers both spatial and channel dimension information,and does not add additional parameters to the original network;combined with the ConvNeXt network in the backbone network,a CvNX module is proposed to reduce the network computing load and retain the target characteristics;SIoU-Loss is then used to replace the original CIoU-Loss to improve the convergence speed of the algorithm;finally,in the image post processing stage,SIoU-NMS is used to reduce the missed detection of targets caused by occlusion.The experimental results on a self-owned low altitude flying object dataset show that the Average Precision(AP)of the improved YOLOv7 algorithm reaches 97.1%,which improves the mean Average Precision(mAP)by 1.7%compared to YOLOv7 algorithm,and the improved YOLOv7 algorithm has low false detection and missed detection rates,meeting the requirements for detecting low altitude flying targets in complex backgrounds.