School of Information Science and Engineering, Xinjiang University, Urumqi 830017, China.
Sensors (Basel). 2023 Jan 9;23(2):767. doi: 10.3390/s23020767.
In view of the fact that the aerial images of UAVs are usually taken from a top-down perspective, there are large changes in spatial resolution and small targets to be detected, and the detection method of natural scenes is not effective in detecting under the arbitrary arrangement of remote sensing image direction, which is difficult to apply to the detection demand scenario of road technology status assessment, this paper proposes a lightweight network architecture algorithm based on MobileNetv3-YOLOv5s (MR-YOLO). First, the MobileNetv3 structure is introduced to replace part of the backbone network of YOLOv5s for feature extraction so as to reduce the network model size and computation and improve the detection speed of the target; meanwhile, the CSPNet cross-stage local network is introduced to ensure the accuracy while reducing the computation. The focal loss function is improved to improve the localization accuracy while increasing the speed of the bounding box regression. Finally, by improving the YOLOv5 target detection network from the prior frame design and the bounding box regression formula, the rotation angle method is added to make it suitable for the detection demand scenario of road technology status assessment. After a large number of algorithm comparisons and data ablation experiments, the feasibility of the algorithm was verified on the Xinjiang Altay highway dataset, and the accuracy of the MR-YOLO algorithm was as high as 91.1%, the average accuracy was as high as 92.4%, and the detection speed reached 96.8 FPS. Compared with YOLOv5s, the -value and mAP values of the proposed algorithm were effectively improved. It can be seen that the proposed algorithm improves the detection accuracy and detection speed while greatly reducing the number of model parameters and computation.
鉴于无人机的航空图像通常是从自上而下的角度拍摄的,存在空间分辨率变化大、小目标检测的问题,并且自然场景的检测方法在任意排列的遥感图像方向下检测效果不佳,难以应用于道路技术状况评估的检测需求场景,本文提出了一种基于 MobileNetv3-YOLOv5s(MR-YOLO)的轻量级网络架构算法。首先,引入 MobileNetv3 结构替代 YOLOv5s 的部分骨干网络进行特征提取,从而减小网络模型的尺寸和计算量,提高目标检测速度;同时,引入 CSPNet 跨阶段局部网络,在保证精度的同时减少计算量。改进焦点损失函数,提高定位精度的同时增加边界框回归速度。最后,通过改进 YOLOv5 目标检测网络的先验帧设计和边界框回归公式,添加旋转角度方法,使其适用于道路技术状况评估的检测需求场景。通过大量算法比较和数据消融实验,在新疆阿勒泰公路数据集上验证了算法的可行性,MR-YOLO 算法的准确率高达 91.1%,平均准确率高达 92.4%,检测速度达到 96.8 FPS。与 YOLOv5s 相比,所提出算法的 mAP 值和 -值均得到了有效提高。可以看出,所提出的算法在大大减少模型参数和计算量的同时,提高了检测精度和检测速度。