Deep Ensemble for Rotorcraft Attitude Prediction

Historically, the rotorcraft community has experienced a higher fatal accident rate than other aviation segments, including commercial and general aviation. Recent advancements in artificial intelligence (AI) and the application of these technologies in different areas of our lives are both intriguing and encouraging. When developed appropriately for the aviation domain, AI techniques provide an opportunity to help design systems that can address rotorcraft safety challenges. Our recent work demonstrated that AI algorithms could use video data from onboard cameras and correctly identify different flight parameters from cockpit gauges, e.g., indicated airspeed. These AI-based techniques provide a potentially cost-effective solution, especially for small helicopter operators, to record the flight state information and perform post-flight analyses. We also showed that carefully designed and trained AI systems could accurately predict rotorcraft attitude (i.e., pitch and yaw) from outside scenes (images or video data). Ordinary off-the-shelf video cameras were installed inside the rotorcraft cockpit to record the outside scene, including the horizon. The AI algorithm could correctly identify rotorcraft attitude at an accuracy in the range of 80\%. In this work, we combined five different onboard camera viewpoints to improve attitude prediction accuracy to 94\%. In this paper, five onboard camera views included the pilot windshield, co-pilot windshield, pilot Electronic Flight Instrument System (EFIS) display, co-pilot EFIS display, and the attitude indicator gauge. Using video data from each camera view, we trained various convolutional neural networks (CNNs), which achieved prediction accuracy in the range of 79\% % to 90\% %. We subsequently ensembled the learned knowledge from all CNNs and achieved an ensembled accuracy of 93.3\%.

The Importance of Robust Features in Mitigating Catastrophic Forgetting

Continual learning (CL) is an approach to address catastrophic forgetting, which refers to forgetting previously learned knowledge by neural networks when trained on new tasks or data distributions. The adversarial robustness has decomposed features into robust and non-robust types and demonstrated that models trained on robust features significantly enhance adversarial robustness. However, no study has been conducted on the efficacy of robust features from the lens of the CL model in mitigating catastrophic forgetting in CL. In this paper, we introduce the CL robust dataset and train four baseline models on both the standard and CL robust datasets. Our results demonstrate that the CL models trained on the CL robust dataset experienced less catastrophic forgetting of the previously learned tasks than when trained on the standard dataset. Our observations highlight the significance of the features provided to the underlying CL models, showing that CL robust features can alleviate catastrophic forgetting.

Susceptibility of Continual Learning Against Adversarial Attacks

The recent advances in continual (incremental or lifelong) learning have concentrated on the prevention of forgetting that can lead to catastrophic consequences, but there are two outstanding challenges that must be addressed. The first is the evaluation of the robustness of the proposed methods. The second is ensuring the security of learned tasks remains largely unexplored. This paper presents a comprehensive study of the susceptibility of the continually learned tasks (including both current and previously learned tasks) that are vulnerable to forgetting. Such vulnerability of tasks against adversarial attacks raises profound issues in data integrity and privacy. We consider all three scenarios (i.e, task-incremental leaning, domain-incremental learning and class-incremental learning) of continual learning and explore three regularization-based experiments, three replay-based experiments, and one hybrid technique based on the reply and exemplar approach. We examine the robustness of these methods. In particular, we consider cases where we demonstrate that any class belonging to the current or previously learned tasks is prone to misclassification. Our observations, we identify potential limitations in continual learning approaches against adversarial attacks. Our empirical study recommends that the research community consider the robustness of the proposed continual learning approaches and invest extensive efforts in mitigating catastrophic forgetting.