Ground impact probability distribution for small unmanned aircraft in ballistic descent

Abstract

Safety is a key factor in all aviation, and while years of development has made manned aviation relatively safe, the same has yet to happen for unmanned aircraft. However, the rapid development of unmanned aircraft technology means that the range of commercial and scientific applications is growing equally rapid. At the same time the trend in national and international regulations for unmanned aircraft is to take a risk-based approach, effectively requiring risk assessment for every flight operation. This work addresses the growing need for methods for quantitatively evaluating individual flights by modelling the consequences of a ballistic descent of an unmanned aircraft as a result of a major in-flight incident. The presented model is a probability density function for the ground impact area based on a second order drag model with probabilistic assumptions on the least well-known parameters of the flight, and includes the effect of wind. The model has low computational complexity and is well-suited for high fidelity simulations for longer flights over populated areas and with changing trajectory parameters.

Crash Area Estimation for Ground Risk of Small Unmanned Aerial Vehicles Due to Propulsion System Failures.

“…Reliability and fault of the drone is one factor that requires special attention to identifying risk in urban and near aerodrome airspace, a study by [13] reported small unmanned aerial vehicles (sUAV) has low reliability compared to commercial aircraft by taking the reliability of sUAV electronic similar as common electronics devices (such as computer disk drives). To understand this situation, some study has simulated a lot of failures scenarios and observed the dynamics of unpowered aircraft to determine the affected area and possible range of these failures [14,15]. The study concluded that most crashes occurred near the initial failure location.…”

“…The predicted descent rate and wind speed have proposed an impact point prediction algorithm to estimate the trajectory from termination to ground impact. [14] used differential equation of the standard second-order drag model suitable for the aircraft debris scene, proposing the probability density function of the UAV's ground crash area. Most of the models proposed from the previous research [15][16][17]19] use a relatively simple method to predict the trajectory and impact point.…”

“…According to the corresponding failure form, MATLAB has used the form of cosimulation with ADAMS to obtain results, including crash time, crash speed, crash trajectory, and impact point. The research in this paper is expected to make a certain contribution to the risk assessment of future multi-rotor sUAV and the corresponding path planning [14,18] by proposing a method to evaluate the crash trajectory and path of the drone, the inherent risk of impact can be controlled and reduced through mitigation measures.…”

Drone Ground Impact Footprints with Importance Sampling: Estimation and Sensitivity Analysis

“…The generation of probability maps has been investigated in other works to provide more information on the impact distributions on the ground that could be useful and reduce conservatism in risk analysis or decision making. In [9], a ballistic model with drag force is considered to represent the descent of a fixed-wing UAV and generate probability density functions of impact points. Uncertainties on drag, initial speed at the instant of failure and external wind are accounted for.…”

Surveillance-based Risk Assessment Model between Urban Air Mobility and Obstacles

“…UAM 항공기와 주변 장애물 간의 충돌위험으로 구분 할 수 있다. 먼저 UAM 항공기의 추락으로 인한 지상 위험의 경우, failure 모형, impact 모형, exposure 모형, harm 모형 등 위험 수준을 정량적으로 평가하 는 데 도움이 될 수 있는 다양한 모형들이 제안되었다 [8][9][10][11][12][13][14]. UAM 항공기(무인기 포함)와 기존의 항공운송 수단 간의 충돌위험의 경우, 경로에 기반한 확률적 모 형 [15]이나 3차원 몬테카를로(Monte-Carlo) 모형 [16] 을 활용하여, UAM 항공기가 공항 주변에서 운용될 때 발생 가능한 충돌위험을 평가하고 UAM 항공기를 위 한 경로를 설계하는 연구들이 진행되었다 [17][18][19].…”