Graph Convolutional Networks for Complex Traffic Scenario Classification

A scenario-based testing approach can reduce the time required to obtain statistically significant evidence of the safety of Automated Driving Systems (ADS). Identifying these scenarios in an automated manner is a challenging task. Most methods on scenario classification do not work for complex scenarios with diverse environments (highways, urban) and interaction with other traffic agents. This is mirrored in their approaches which model an individual vehicle in relation to its environment, but neglect the interaction between multiple vehicles (e.g. cut-ins, stationary lead vehicle). Furthermore, existing datasets lack diversity and do not have per-frame annotations to accurately learn the start and end time of a scenario. We propose a method for complex traffic scenario classification that is able to model the interaction of a vehicle with the environment, as well as other agents. We use Graph Convolutional Networks to model spatial and temporal aspects of these scenarios. Expanding the nuScenes and Argoverse 2 driving datasets, we introduce a scenario-labeled dataset, which covers different driving environments and is annotated per frame. Training our method on this dataset, we present a promising baseline for future research on per-frame complex scenario classification.Comment: Netherlands Conference on Computer Vision (NCCV) 2023 camera-ready + supplementary materia

Deep Learning-based Driver Behavior Modeling and Analysis

Driving safety continues receiving widespread attention from car designers, safety regulators, and automotive research community as driving accidents due to driver distraction or fatigue have increased drastically over the years. In the past decades, there has been a remarkable push towards designing and developing new driver assistance systems with much better recognition and prediction capabilities. Equipped with various sensory systems, these Advanced Driver Assistance Systems (ADAS) are able to accurately perceive information on road conditions, predict traffic situations, estimate driving risks, and provide drivers with imminent warnings and visual assistance. In this thesis, we focus on two main aspects of driver behavior modeling in the design of new generation of ADAS. We first aim at improving the generalization ability of driver distraction recognition systems to diverse driving scenarios using the latest tools of machine learning and connectionist modeling, namely deep learning. To this end, we collect a large dataset of images on various driving situations of drivers from the Internet. Then we introduce Generative Adversarial Networks (GANs) as a data augmentation tool to enhance detection accuracy. A novel driver monitoring system is also introduced. This monitoring system combines multi-information resources, including a driver distraction recognition system, to assess the danger levels of driving situations. Moreover, this thesis proposes a multi-modal system for distraction recognition under various lighting conditions and presents a new Convolutional Neural Network (CNN) architecture, which can operate real-time on a resources-limited computational platform. The new CNN is built upon a novel network bottleneck of Depthwise Separable Convolution layers. The second part of this thesis focuses on driver maneuver prediction, which infers the direction a driver will turn to before a green traffic light is on and predicts accurately whether or not he/she will change the current driving lane. Here, a new method to label driving maneuver records is proposed, by which driving feature sequences for the training of prediction systems are more closely related to their labels. To this end, a new prediction system, which is based on Quasi-Recurrent Neural Networks, is introduced. In addition, and as an application of maneuver prediction, a novel driving proficiency assessment method is proposed. This method exploits the generalization abilities of different maneuver prediction systems to estimate drivers' driving abilities, and it demonstrates several advantages against existing assessment methods. In conjunction with the theoretical contribution, a series of comprehensive experiments are conducted, and the proposed methods are assessed against state-of-the-art works. The analysis of experimental results shows the improvement of results as compared with existing techniques

Collection and Analysis of Driving Videos Based on Traffic Participants

Autonomous vehicle (AV) prototypes have been deployed in increasingly varied environments in recent years. An AV must be able to reliably detect and predict the future motion of traffic participants to maintain safe operation based on data collected from high-quality onboard sensors. Sensors such as camera and LiDAR generate high-bandwidth data that requires substantial computational and memory resources. To address these AV challenges, this thesis investigates three related problems: 1) What will the observed traffic participants do? 2) Is an anomalous traffic event likely to happen in near future? and 3) How should we collect fleet-wide high-bandwidth data based on 1) and 2) over the long-term? The first problem is addressed with future traffic trajectory and pedestrian behavior prediction. We propose a future object localization (FOL) method for trajectory prediction in first person videos (FPV). FOL encodes heterogeneous observations including bounding boxes, optical flow features and ego camera motions with multi-stream recurrent neural networks (RNN) to predict future trajectories. Because FOL does not consider multi-modal future trajectories, its accuracy suffers from accumulated RNN prediction error. We then introduce BiTraP, a goal-conditioned bidirectional multi-modal trajectory prediction method. BiTraP estimates multi-modal trajectories and uses a novel bi-directional decoder and loss to improve longer-term trajectory prediction accuracy. We show that different choices of non-parametric versus parametric target models directly influence predicted multi-modal trajectory distributions. Experiments with two FPV and six bird's-eye view (BEV) datasets show the effectiveness of our methods compared to state-of-the-art. We define pedestrian behavior prediction as a combination of action and intent. We hypothesize that current and future actions are strong intent priors and propose a multi-task learning RNN encoder-decoder network to detect and predict future pedestrian actions and street crossing intent. Experimental results show that one task helps the other so they together achieve state-of-the-art performance on published datasets. To identify likely traffic anomaly events, we introduce an unsupervised video anomaly detection (VAD) method based on trajectories. We predict locations of traffic participants over a near-term future horizon and monitor accuracy and consistency of these predictions as evidence of an anomaly. Inconsistent predictions tend to indicate an anomaly has happened or is about to occur. A supervised video action recognition method can then be applied to classify detected anomalies. We introduce a spatial-temporal area under curve (STAUC) metric as a supplement to the existing area under curve (AUC) evaluation and show it captures how well a model detects temporal and spatial locations of anomalous events. Experimental results show the proposed method and consistency-based anomaly score are more robust to moving cameras than image generation based methods; our method achieves state-of-the-art performance over AUC and STAUC metrics. VAD and action recognition support event-of-interest (EOI) distinction from normal driving data. We introduce a Smart Black Box (SBB), an intelligent event data recorder, to prioritize EOI data in long-term driving. The SBB compresses high-bandwidth data based on EOI potential and on-board storage limits. The SBB is designed to prioritize newer and anomalous driving data and discard older and normal data. An optimal compression factor is selected based on the trade-off between data value and storage cost. Experiments in a traffic simulator and with real-world datasets show the efficiency and effectiveness of using a SBB to collect high-quality videos over long-term driving.PHDRoboticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/168035/1/brianyao_1.pd