Integrating aircraft warning systems

Aerospace Engineerin

Reconstruction of Pilot Behaviour from Cockpit Image Recorder

A method to automatically identify pilot actions from cockpit camera footage is reported in this paper. Although they have long been considered for the enhancement of flight safety, cockpit image recorders have not yet been standard equipment in aircraft cockpits. The rules on Flight Data Recorders have been changed, however, to include a cockpit image recorder as one of the safety devices, and it is recommended to be installed in small aircraft as a substitute for a Flight Data Recorder. With cockpit images becoming available, it would surely be useful for accident analysis as well as for daily flight analysis. Especially for the latter purpose, pilot behavior should be automatically analyzed and classified into specific actions, or procedures. The authors conducted a study to assess the feasibility of automatic detection of pilot actions in the cockpit by a machine learning process. Results show that even with a small amount of training data, the resulting algorithm could identify some typical actions, such as manipulation of the switches on the glare shield, with 80% accuracy. Even in cases with a button and a switch positioned very close to each other, the actions ‘pushing the switch’ and ‘pushing the button’ could be distinguished by the algorithm. The action estimation accuracy improves up to 90% when using the training data focused on the pilot’s body parts, rather than the data focused on the whole body.Invited paperControl & Simulatio

Situation Awareness Prompts: Bridging the Gap between Supervisory and Manual Air Traffic Control

To meet increasing safety and performance demands in air traffic control (ATC), more advanced automated systems will be introduced to assist human air traffic controllers. Some even foresee complete automation, with the human as a supervisor only to step-in when automation fails. Literature and empirical evidence suggest that supervising highly-automated systems can cause severe vigilance and complacency problems, out-of-the-loop situation awareness and transient workload peaks. These impair the ability for humans to successfully take over control. In this study, situation awareness prompts were used as a way to keep controllers cognitively engaged during their supervision of a fully automated ATC system. Results from an exploratory human-in-the-loop experiment, in which eight participants were instructed to monitor a fully automated ATC system in a simplified ATC context, show a significant decrease in workload peaks following an automation failure after being exposed to high-level SA questions. Although the selected method did not necessarily yield improved safety and manual control efficiency, results suggest that using situation awareness feedback in line with controllers' attention could be an avenue worth exploring further as a training tool.Control & Simulatio

A dimensionality reduction approach in helicopter level flight performance testing

Evaluation of the power required in level flight is essential to any new or modified helicopter performance flight-testing effort. The conventional flight-test method is based on an overly simplification of the induced and profile power components required for a helicopter in level flight. This simplistic approach incorporates several drawbacks that not only make execution of flight sorties inefficient and time consuming, but also compromise the level of accuracy achieved. This paper proposes an alternative flight-test method for evaluating the level-flight performance of a conventional helicopter while addressing and rectifying all identified deficiencies of the conventional method. The proposed method, referred to as the corrected-variables screening using dimensionality reduction (CVSDR), uses an original list of 36 corrected variables derived from basic dimensional analysis principles. This list of 36 corrected variables is reduced using tools of dimensionality reduction to keep only the most effective level-flight predictors. The CVSDR method is demonstrated and tested in this paper using flight-test data from a MBB BO-105 helicopter. It is shown that the CVSDR method predicts the power required for level flight about 21% more accurately than the conventional method while reducing the required flight time by an estimate of at least 60%. Unlike the conventional method, the CVSDR is not bounded by the high-speed approximation associated with the induced power estimation, therefore it is also relevant to the low airspeed regime. This low-airspeed relevancy allows the CVSDR method to bridge between the level-flight regime and the hover. Although demonstrated in this paper for a specific type of helicopter, the CVSDR method is applicable for level-flight performance flight testing of any type of conventional helicopter. Control & Simulatio

Linear Mixed-Effects Models for Human-in-the-Loop Tracking Experiment Data

Linear mixed-effects models provide several benefits over more traditional statistical inference tests and are particularly useful for most human-in-the-loop tracking experiment data. However, surprisingly, mixed models are virtually not used for the analysis of tracking experiment data. This paper uses linear mixed-effects models to analyze combined tracking data from two previous human-in-the-loop roll tracking experiments that compared control behavior metrics collected in both a research aircraft and a motion-base simulator. In the experiments, pilots' behavior under 10 different motion configurations with varying motion filter gains and break frequencies was evaluated and compared to that in the real aircraft. The linear mixed-effects model analysis on the combined dataset confirmed the main statistical outcomes of the individual experiments. The main benefits of mixed models for this type of data were demonstrated by successfully combining data from two experiments that used different experimental conditions and of which one had an additional apparatus and the other a missing participant. Finally, the mixed-model analysis was able to explicitly test for scientifically relevant statistical differences in the dependent measures between the aircraft and simulator, as well as between both experiments.Virtual/online event due to COVID-19Control & Simulatio

Motorcycle simulator subjective and objective validation for low speed maneuvering

The use of driving simulators for training and for development of new vehicles is widely spread in the automotive industry. In the last decade, a few motorcycle riding simulators have been developed for similar purposes, with focus on maneuvering at high speed. This article presents the subjective and objective evaluation of a motorcycle riding simulator specifically for low speed longitudinal and lateral maneuvering, between 0 and 10 ms–1. An experiment was conducted with and without platform motion, focusing on three maneuvers: acceleration from standstill, braking to standstill and turning at constant speed. Participants briefly evaluated the fidelity of the simulator after each maneuver and more extensively after each motion condition. Behavioral fidelity was evaluated using experimental data measured on an instrumented motorcycle. Overall, the results show that the participants could reproduce the selected maneuvers without falling or losing balance, reporting a sufficient level of simulator realism. In terms of subjective fidelity, platform motion had a positive effect on simulator presence, significantly increasing the feeling of being involved in the virtual environ0ment. In terms of behavioral fidelity, the comparison between the simulator and experimental results shows good agreement, with a limited positive influence of motion for the braking maneuver, which indicates that for this maneuver the use of motion is beneficial to reproduce the real-life experience and performance.Intelligent VehiclesControl & Simulatio

A singular values approach in helicopter gas turbine engines flight testing analysis

The process of empirical models evaluation is at the core business of experimental flight-testing data analysis. Accurate and convenient flight-testing of helicopter engine(s) available power is crucial for predicting the total helicopter performance. Common practice in estimation of in-flight helicopter gas turbine engine power consists of a reduction of flight-test data into simplistic single-variable analysis approach. While such an approach is convenient for practical use, it often results in unrealistic predictions of the available engine(s) power. A novel approach for the helicopter available power problem is the so-called Multivariable Polynomial Optimization under Constraints method. In this method, 18 regressors, constructed from the engine non-dimensional parameters, are used to define empirical polynomial models. This paper is intended to complement the Multivariable Polynomial Optimization under Constraints method and answer the question of which multivariable polynomial can be generally used in representing helicopter gas-turbine engine performance? In this sense, a variety of seven gas-turbine engines installed on different helicopters are analyzed, each one giving 512 possible polynomial models to be used for available-power calculations. While conventional statistical methods of hypothesis-testing failed in providing the answer to the question stated above of which the best general empirical model for representing engine performance is, an alternative approach based on the Singular-Value-Decomposition theorem, was proven successful in providing the answer. Moreover, this approach presented in the paper yielded a short list of 10 simple and convenient multivariable polynomials, best representing the performance of all seven engines analyzed as a group.Control & Simulatio

Human crossfeed in dual-axis manual control with motion feedback

While many realistic manual control tasks require human operators to control multiple degrees-of-freedomsimultaneously, our understanding of such multi-axis manual control has not moved far beyond considering it simply as the control of multiple fully-independent axes. This investigation aims to further our understanding of multi-axis control by focusing on one phenomenon that is known to occur in such tasks: crossfeed. Crossfeed occurs when operators’ inputs in one controlled axis feed into another controlled degree-of-freedom, thereby affecting overall control performance. A human-in-the-loop experiment, in which operators performed a dual-axis aircraft roll and pitch tracking task with physical motion feedback, was conducted in the SIMONA Research Simulator at TU Delft. Three conditions were tested: the full dual-axis control task, supplemented with reference single-axis roll and pitch tasks. Through the use of independent target and disturbance forcing function signals in both controlled axes, we were able to detect the presence of crossfeed in this dual-axis task from spectral analysis. Furthermore, these signals facilitated the objective identification of the dynamics of the crossfeed contribution, in parallel with estimating operators visual and motion responses. The crossfeed dynamics were found to resemble the well-known dynamics of human operators’ visual responses. The crossfeed contribution was found to explain up to 20% of the measured control inputs, thereby indicating that crossfeed can be a factor of significance in multi-axis manual control.Control & SimulationControl & OperationsBiomechatronics & Human-Machine Contro

Human Performance in Solving Multi-UAV Over-Constrained Dynamic Vehicle Routing Problems

For many logistics applications, such as drone delivery missions, finding an optimized network of routes yields a Vehicle Routing Problem (VRP). Such optimizations are mostly conducted offline prior to actual operations for reasons of computational complexity. In case disturbances arise during operations, for example a sudden loss of a vehicle, the VRP needs to be re-optimized in real-time and this raises concerns regarding obtaining a solution within time. In a previous study, it was demonstrated that humans, when supported through a human-machine interface, can quickly deal with these routing problems through satisficing, providing workable solutions. This paper extends our previous research by exposing human operators to an over-constrained VRP with different mission priorities and vehicle capabilities. Experiment results (n = 16) indicate that the mission type had the largest impact on how participants used the interface and what constraints were relaxed. In particular, during a search-and-rescue context the mission emphasis was put on delivering (medical) payload (close) to as many customers as possible, even if this would involve sacrificing vehicles and relaxing the depot constraint. Ethical aspects of the VRP are taken into account which algorithms do not by themselves, underlining the importance of involving humans in automation. Human operators complement algorithms with their context awareness, yielding more safe, resilient and responsible systems.Control & Simulatio

Evaluation of a 3D Solution Space-based ATC Workload Metric

Air Traffic Control (ATC) workload is a limiting factor for air traffic growth, creating a need for objective ATC workload metrics. Previous research has shown that the solution space diagram can be a basis for a workload prediction metric. The current solution space metric however, does not incorporate altitude. In this paper, a 3D solution space metric is described and evaluated. An experiment has been conducted to test the relation of the 3D solution space metric with workload and compare it to other workload metrics; the aircraft count, and a quasi-3D metric: the 2D layered solution space and the Instantaneous Self Assessment-based method. Weak correlations with workload were found for all tested metrics and no significant differences were found between them. Although no significant differences were found, the 2D layered metric showed better results than the 3D solution space-based metric, indicating that air traffic controllers might think in 2D layers over fixed altitude ranges rather than considering the complete 3D physical solution space.Control & Simulatio