Computer Vision for Autonomous UAV Flight Safety: An Overview and a Vision-based Safe Landing Pipeline Example

Recent years have seen an unprecedented spread of Unmanned Aerial Vehicles (UAVs, or “drones”), which are highly useful for both civilian and military applications. Flight safety is a crucial issue in UAV navigation, having to ensure accurate compliance with recently legislated rules and regulations. The emerging use of autonomous drones and UAV swarms raises additional issues, making it necessary to transfuse safety- and regulations-awareness to relevant algorithms and architectures. Computer vision plays a pivotal role in such autonomous functionalities. Although the main aspects of autonomous UAV technologies (e.g., path planning, navigation control, landing control, mapping and localization, target detection/tracking) are already mature and well-covered, ensuring safe flying in the vicinity of crowds, avoidance of passing over persons, or guaranteed emergency landing capabilities in case of malfunctions, are generally treated as an afterthought when designing autonomous UAV platforms for unstructured environments. This fact is reflected in the fragmentary coverage of the above issues in current literature. This overview attempts to remedy this situation, from the point of view of computer vision. It examines the field from multiple aspects, including regulations across the world and relevant current technologies. Finally, since very few attempts have been made so far towards a complete UAV safety flight and landing pipeline, an example computer vision-based UAV flight safety pipeline is introduced, taking into account all issues present in current autonomous drones. The content is relevant to any kind of autonomous drone flight (e.g., for movie/TV production, news-gathering, search and rescue, surveillance, inspection, mapping, wildlife monitoring, crowd monitoring/management), making this a topic of broad interest.

Attitude-pendulum-sloshing coupled dynamics of quadrotors slung liquid containers

Quadrotors suspended water containers may be used for fire-fighting services. Unfortunately, the complicated dynamics in this type of system degrade the flight safety because of coupling effects among the quadrotor attitude, container swing, and liquid sloshing. However, few effects have been directed at the attitude-pendulum-sloshing dynamics in this type of aerial cranes. A novel planar model of a quadrotor carrying a liquid tank under dual-hoist mechanisms is presented. The model includes vehicle-attitude dynamics, load-swing dynamics, and fluid-sloshing dynamics. Resulting from the model, a new method is proposed to control coupled oscillations among the vehicle attitude, load swing, and fluid sloshing. Numerous simulations on the nonlinear model demonstrate that the control method can reduce the undesirable oscillations, stabilize the quadrotor’s attitude, and reject the external disturbances. The theoretical findings may also extend to the three-dimensional dynamics of quadrotors slung liquid tanks, and other types of aerial vehicles transporting liquid containers including helicopters or tiltrotors.

Embracing Simulations and Problem-Based Learning to Effectively Pair Concepts of Aeronautics With Flight Safety Training

Cadets, in order to become pilots, apart from successfully passing their flight training program, need to also complete their academic education, where many technical subjects, such as aeronautics, exist. Cadets often face difficulties in comprehending certain concepts in the subject “aeronautics” as well as the applied link between aeronautics and flight safety. To this end, at the Hellenic Air Force Academy, an innovative educational tool is under development so as to facilitate students' understanding of the practical use of aeronautics and its impact on aircraft safety. An important aspect of the proposed educational tool is that it can be easily adopted into the pilots' flight training program and offer a complimentary training experience regarding mid-air crisis scenarios. The new educational tool is based on introducing in-class simulation and problem-based learning, thus combining theory and practice. The aim of this chapter is to describe the development of this educational tool and to demonstrate the way that it can be employed for academic and flight training purposes.

Sistem Status Kelaikudaraan Pesawat Udara Berbasis Website Menggunakan Framework CodeIgniter dan PostgreSQL dengan Metode Prototype

In aircraft operation, maintenance must always be carried out so that the aircraft meets airworthiness standards in order to meet flight safety, in which maintenance is carried out on aircraft components on a regular basis. The problem that exists today is that there is frequent damage to the aircraft without any known cause, even when the aircraft is flown which results in the plane crashing and experiencing severe damage until it can no longer be used. This condition is due to the absence of a system that can monitor the aircraft maintenance process, so that the components of the aircraft used to be flown cannot be known whether it is airworthy or not. The solution to overcome this problem is by building a website-based system. The system was built using the CodeIgniter framework and PostgreSQL as its database. Meanwhile, for system development using the Prototype method. Through this system the aircraft maintenance process can be carried out according to the existing schedule.

Command-methodological competence of cadets-military pilots as a factor of flight safety

The military professional training of cadets-military pilots in a military aviation university is conditioned by the trends in the development of military education, its prompt response to the personnel needs of the troops. Aviation units need military pilots who are ready to fulfill the official duties of crew commanders, to solve the urgent task of ensuring flight safety. Training of flight personnel for military aviation does not fully take into account the need to form cadets' competencies as an aviation commander and teacher, which will contribute to ensuring flight safety and increasing the combat potential of aviation units and subunits. The article deals with the problem of flight safety as a factor affecting the national security of Russia, paying attention to the causes of accidents and pilot errors. In the course of the study, it was proved that the military-professional activity of cadets-military pilots is the process of solving professional tasks that ensure the combat readiness of aviation units while observing flight safety conditions. Based on the content analysis of the command and methodological professional tasks based on the activity approach, the leading role of the command-methodological activity has been established. The functional approach and the principle of identification made it possible to identify the functions of the leading command-methodological activity (military flight training and educational, organizational and managerial). Arguments are given regarding the development of cadets not only a set of abilities for command-methodological activity, but also professionally important qualities that integrate command-methodological competence. The structure of competence (motivational-value, cognitive, activity components) is determined taking into account the specifics (leading type of activity) and features (a set of command and methodological professional tasks) of military professional activity. The criteria for the formation of the components of the command-methodical competence (professional purposefulness, intellectual potential, professional responsibility) have been identified. The methodological basis of the pedagogical system for the formation of the command-methodical competence of cadets-military pilots was formed by the system-structural, personality-activity, functional, modular, adaptive, technological and competence-based approaches. The results of the experimental work carried out in the branch of Military Educational-Research Centre of Air Force Air Force Academy in Syzran confirmed the dependence of the cadets' readiness for flight safety activities on the formation of command-methodological competence.

Artificial Intelligence-Based Aircraft Accident Threat Parrying Method

An anti-aircraft accident method is proposed, implemented in the decision support module, which is the main element of the flight safety control system and is a dynamic expert system. On the basis of the proposed method, recommendations are formed to the threat countering crew accidents using the information about its psychophysical state, the technical state an aircraft, external influencing factors, as well as a forecast of changes in flight conditions. The advantage of the proposed method is the ability to identify the immediate threat of an accident, as well as the development of management decisions to reduce the impact of the cause of the accident on flight safety. The peculiarity of the method of parrying the threat of an aircraft accident is the classification of management decisions depending on the flight conditions of the aircraft, which will reduce the computational costs for generating a threat parrying signal. Numerical modeling of the work using the assessment of a set of decision support rules made it possible to confirm its performance. The results can be used in systems development for safety an aircraft’s flight, the mathematical support of decision support systems.

Oil Fumes, Flight Safety, and the NTSB

During its investigations into a series of ten aircraft crashes from 1979 to 1981, US National Transportation Safety Board (NTSB) officials were presented with a hypothesis that “several” of the crashes could have been caused by pilot impairment from breathing oil fumes inflight. The NTSB and their industry partners ultimately dismissed the hypothesis. The authors reviewed the crash reports, the mechanics of the relevant engine oil seals, and some engine bleed air data to consider whether the dismissal was justified. Four of the nine aircraft crash reports include details which are consistent with pilot impairment caused by breathing oil fumes. None of the tests of ground-based bleed air measurements of a subset of oil-based contaminants generated in the engine type on the crashed aircraft reproduced the inflight conditions that the accident investigators had flagged as potentially unsafe. The NTSB’s conclusion that the hypothesis of pilot incapacitation was “completely without validity” was inconsistent with the evidence. Parties with a commercial conflict of interest should not have played a role in the investigation of their products. There is enough evidence that pilots can be impaired by inhaling oil fumes to motivate more stringent design, operation, and reporting regulations to protect safety of flight.

INVESTIGATION OF THE INFLUENCE OF CORRELATED COLOR TEMPERATURE OF LED illuminatorS AS A FACTOR OF SAFETY LIGHTING OF HIGHWAYS FOR DIFFICULT WEATHER CONDITIONS

A investigation of the dependence of relative horizontal illumination level and brightness of the most common types of road surface in Ukraine when using LED illuminators with different spectral distribution of radiation in the presence of aerial aerosols of different optical densities (strong, moderate, weak fog and haze) is performed. Mathematical models of LED illuminators with correlated color temperature Tcc = (2200÷8400) K in the visible range of the spectrum λ = (380÷780) nm have been created. Their use together with the selected model of the spectral dependence of the scattering index β (λ) (Ferdinandоv’s model) of the atmospheric environment with the presence of aqueous aerosols, which cause a limited meteorological range of visibility MOR = (0.1÷3) km, showed a slight (1%) advantage in creation of illumination from lamps of a warm spectrum of radiation (TCC = 2200 K) in comparison with cold (Tcc = 8400 K) for cases of strong fogs with MOR = 100 m. Calculations involving the analysis of mathematical modeling of the spectral distribution of the reflection coefficients for two types of road surface (new and worn asphalt) proved that when using warm spectrum illuminators the brightness of the most common in Ukraine old asphalt pavement in the conditions of MOR = 100 m by 5% exceeds the corresponding value of the cold spectrum emitters. This difference gradually decreases as visibility is improved due to the weaker spectral dependence of β (λ) and at MV = 3 km is 4.5%. The advantage of using warm spectrum illuminators will be significantly enhanced for the case of estimating the brightness of the coverage over long distances, for example, airfield runways, which will significantly improve flight safety.

Using Heinrich’s (Bird’s) Pyramid of Adverse Events to Assess the Level of Safety in an Airline

One of the key concepts in matters of flight safety is that of special (abnormal) situations, with airworthiness regulation and certification of aviation equipment being based on this concept. At the same time, one is forced to admit that today there is no explicit interpretation of the standardized traits of special situations, nor are they not fully elucidated in the scientific literature. In this article we propose a pyramid-based approach to interpreting special (abnormal) in-flight situations, which allows for risk assessment not using risk matrices, but instead relying only on the probabilistic characteristics of the occurrence of events. Using the presence of a causal relationship between the layers of the pyramid, we propose an algorithm for the transition of varying degrees of danger of special situations. This algorithm can be used to develop an on-board device that informs the pilot about the dynamics of transitions from one situation to another, representing each emergency situation in a certain color.