Operational issues and assessment of risk for light UAVs

Liu

Journal of Advanced Transportation

et al. 2018

This paper proposes an effective approach for modelling and assessing the risks associated with unmanned aerial vehicles (UAVs) integrated into national airspace system (NAS). Two critical hazards with UAV operations are considered and analyzed, which are ground impacts and midair collisions. Threats to fatalities that result from the two hazards are the focus in the proposed method. In order to realize ground impact assessment, a multifactor risk model is designed by calculating system reliability required to meet a target level of safety for different UAV categories. Both fixed-wing and rotary-wing UAVs are taken into account under a real scenario that is further partitioned into different zones to make the evaluation more precise. Official territory and population data of the operation scenario are incorporated, as well as UAV self-properties. Casualty area of impacting debris can be obtained as well as the probability of fatal injuries on the ground. Sheltering factors are not neglected and defined as four types based on the real scenario. When midair collision fatality risk is estimated, a model of aircraft collisions based on the density of civil flight in different regions over Chinese airspace is proposed. In the model, a relative collision area and flying speed between UAVs and manned aircraft are constructed to calculate expected frequency of fatalities for each province correspondingly. Truthful data with different numbers of UAVs is incorporated in the model with the expected number of fatalities after a collision is included. Experimental simulations are made to evaluate the ground impacts and midair collisions when UAVs operate in the NAS.

Section: Model Simulationsmentioning

confidence: 99%

Safety Assessment and Risk Estimation for Unmanned Aerial Vehicles Operating in National Airspace System

Liu

Journal of Advanced Transportation

et al. 2018

Proceedings of the Institution of Mechanical Engineers, Part G:

“…Based on the literature, 3,9 we can reasonably suggest that initial impact angle θi is in the range of 30°–60°. The expected impact velocity values V i are determined by the type and mass of UAS, as well as impact scenarios, i.e.…”

Section: Methodsmentioning

confidence: 72%

“…3,7 Therefore, the rebounce distance of sUAS after the ground collision is important to estimate the safe range of personnel on the ground, which is different from the traditional lethal area that is defined as the possible lethal range before the UAS impacts the ground. 8,9…”

Section: Introductionmentioning

confidence: 99%

Modeling the motion of small unmanned aerial system (sUAS) due to ground collision

Dori

Divo

et al. 2017

The aim of this paper is to develop a modeling method in order to predict the rebounce distance of a small size unmanned aerial system (sUAS) after collision with the ground. This distance would be useful to determine the safe range on the ground when operating the UAS. A two-step strategy is developed to model this procedure. In step one, numerical simulations are performed to model the first impact and predict the rebounce angle and impact velocity. Based on the information obtained, in step two, an analytical model is employed to calculate the rebounce distance without running numerical simulations, to save the computational time. Based on the model predictions, a non-linear function (known as a Meta model) is established to describe the rebounce behavior as a function of impact parameters, i.e. impact velocity, angle, and friction coefficient between the vehicle and ground. A correlation analysis is further performed to analyze the effect of these parameters on the response. The results show that the maximum rebounce range could be greater than 10 m. Compared to impact angle and friction coefficient, impact velocity is the most significant factor influencing the rebounce range. The larger velocity, smaller impact angle, and smaller ground friction coefficient would lead to the large rebounce range. The established Meta model would be useful to estimate safety range when operating sUAS platforms.

“…Though UAVs can disturb wildlife, when used responsibly, a UAV may be less likely to disturb wildlife than a fullsized helicopter (Martin 2014) while installing line markers. Despite these advantages, application of UAVs to wildlife conservation is limited by uncertainty in governmental regulations (Guglieri et al 2014). Commercial organizations seeking to operate UAVs in the U.S. must file a petition with the FAA pursuant to Section 333 of the FAA Modernization and…”

Section: Discussionmentioning

confidence: 99%

Mitigating avian collision with power lines: a proof of concept for installation of line markers via unmanned aerial vehicle

Lobermeier

Moldenhauer

Peter

et al. 2015

J. Unmanned Veh. Sys.

Avian collisions with overhead power lines are a global conservation concern. Collisions are mitigated primarily through marking power lines to increase their visibility. Line marking is typically accomplished via an expensive and potentially dangerous process of hovering a helicopter within 1 m of a wire and installing line markers by hand. Unmanned Aerial Vehicles (UAVs) may offer a less dangerous, less costly alternative that is also less disturbing to wildlife. Herein we describe equipping a commercially available UAV with an installation arm designed in collaboration with the Colorado State University Department of Mechanical Engineering to install line markers on a power line. The UAV installed line markers within a 30 cm target window on a model power line. The proof of concept described here demonstrates the potential utility of UAVs in mitigating avian collision with overhead power lines.