Object detection is a core task in autonomous driving perception systems, designed to enable vehicles to detect and pinpoint various objects in their surrounding environment in real time (such as vehicles, pedestrians, and traffic signs). Functioning as the intelligent "eyes" that interpret road scenes, it forms the foundation for safe driving decisions and path planning.
Object detection for autonomous driving is primarily driven by deep learning algorithms. Its workflow can be broken down into two essential steps:
Feature Extraction: The algorithm first extracts critical visual features—such as edges, textures, and geometric shapes—from raw image or point cloud data captured by on-board sensors like cameras and radars.
Classification and Localisation: Based on the extracted features, the algorithm classifies each object (determining whether it is a vehicle, pedestrian, or road sign) and uses bounding boxes to pinpoint its exact spatial position.
Based on their computational architecture, mainstream algorithms are broadly divided into two categories:
One-Stage Detection Algorithms (One-Stage): Exemplified by the YOLO series, these prioritise processing speed. By treating object detection as a direct regression problem, the algorithm predicts object classes and spatial coordinates simultaneously in a single forward pass. This end-to-end design delivers ultra-fast processing speeds that meet the stringent real-time demands of autonomous driving, making it the industry standard. For instance, the latest YOLO11 model delivers 25 frames per second on embedded platforms, while refined YOLOv8-based variants achieve a mean average precision (mAP) of up to 98.3% on benchmark datasets.
Two-Stage Detection Algorithms (Two-Stage): Exemplified by the Faster R-CNN series, these focus on precision. The system first deploys a Region Proposal Network (RPN) to identify candidate regions of interest, followed by fine-grained classification and bounding-box refinement on those specific areas. While this multi-step approach yields superior detection precision, it incurs heavier computational overheads and operates at comparatively slower speeds.
In complex real-world driving environments, object detection encounters major challenges such as dense traffic occlusion, adverse weather, and poor lighting, all of which can compromise detection stability. As such, real-time responsiveness (millisecond-level latency) and accuracy (high precision and high recall rates) serve as the definitive benchmarks for evaluating algorithm capability. To boost system robustness, developers continue to introduce advanced techniques, such as attention mechanisms to focus on key features, and multi-scale feature fusion networks to sharpen the detection of small and partially occluded obstacles.