Beyond Object Detection with Existence Maps for Anchor-Based Deep Learning Models

LiDAR-based object detection models have achieved impressive accuracy in autonomous driving benchmarks. However, despite improvements in efficiency, these models lack interpretability and measured accuracies are heavily dataset-dependent, reflecting closed-set performance. Further, in the real-world, many dynamic situations arise, inducing inevitable perception errors. To address these limitations, we propose a twofold approach: first, we introduce the Existence Map, a method to visualise the internal knowledge of deep learning models that suggests existence of objects, and second, we propose a methodology to merge this information with the standard output, supplementing detections and calibrating final confidences, reducing the mean absolute error in 12.3%. Further, our experiments on the KITTI dataset demonstrate that the merging strategy can enhance precision and recall by 0.03 and 0.04, respectively, when evaluated across all ground-truth classes despite the model being trained on only cars, pedestrians and cyclists. Additionally, we show that existence maps can help identify missed objects, reduce false positives, and capture location uncertainties, leading to improved performance and increased interpretability in safety-critical object detection applications.