Leveraging Monte Carlo Dropout for Uncertainty Quantification in Real-Time Object Detection of Autonomous Vehicles

With the recent advancements in machine learning technology, the accuracy of autonomous driving object detection models has significantly improved. However, due to the complexity and variability of real-world traffic scenarios, such as extreme weather conditions, unconventional lighting, and unknown traffic participants, there is inherent uncertainty in autonomous driving object detection models, which may affect the planning and control in autonomous driving. Thus, the rapid and accurate quantification of this uncertainty is crucial. It contributes to a better understanding of the intentions of autonomous vehicles and strengthens trust in autonomous driving technology. This research pioneers in quantifying uncertainty in the YOLOv5 object detection model, thereby improving the accuracy and speed of probabilistic object detection, and addressing the real-time operational constraints of current models in autonomous driving contexts. Specifically, a novel probabilistic object detection model named M-YOLOv5 is proposed, which employs the MC-drop method to capture discrepancies between detection results and the real world. These discrepancies are then converted into Gaussian parameters for class scores and predicted bounding box coordinates to quantify uncertainty. Moreover, due to the limitations of the Mean Average Precision (MAP) evaluation metric, we introduce a new measure, Probability-based Detection Quality (PDQ), which is incorporated as a component of the loss function. This metric simultaneously assesses the quality of label uncertainty and positional uncertainty. Experiments demonstrate that compared to the original YOLOv5 algorithm, the M-YOLOv5 algorithm shows a 74.7% improvement in PDQ. When compared with the most advanced probabilistic object detection models targeting the MS COCO dataset, M-YOLOv5 achieves a 14% increase in MAP, a 17% increase in PDQ, and a 65% improvement in FPS. Furthermore, against the state-of-the-art probabilistic object detection models for the BDD100K dataset, M-YOLOv5 exhibits a 31.67% enhancement in MAP and a 125.6% increase in FPS.