Real-time Object Detection and Associated Hardware Accelerators Targeting Autonomous Vehicles: A Review

The efficiency of object detectors depends on factors like detection accuracy, processing time, and computational resources. Processing time is crucial for real-time applications, particularly for autonomous vehicles (AVs), where instantaneous responses are vital for safety. This review paper provides a concise yet comprehensive survey of real-time object detection (OD) algorithms for autonomous cars delving into their hardware accelerators (HAs). Non-neural network-based algorithms, which use statistical image processing, have been entirely substituted by AI algorithms, such as different models of convolutional neural networks (CNNs). Their intrinsically parallel features led them to be deployable into edge-based HAs of various types, where GPUs and, to a lesser extent, ASIC (application-specific integrated circuit) remain the most widely used. Throughputs of hundreds of frames/s (fps) could be reached; however, handling object detection for all the cameras available in a typical AV requires further hardware and algorithmic improvements. The intensive competition between AV providers has limited the disclosure of algorithms, firmware, and even hardware platform details. This remains a hurdle for researchers, as commercial systems provide valuable insights while academics undergo lengthy training and testing on restricted datasets and road scenarios. Consequently, many AV research papers may not be reflected in end products, being developed under limited conditions. This paper surveys state-of-the-art OD algorithms and aims to bridge the gap with technologies in commercial AVs. To our knowledge, this aspect has not been addressed in earlier surveys. Hence, the paper serves as a tangible reference for researchers designing future generations of vehicles, expected to be fully autonomous for comfort and safety.