A novel 3D analytical algorithm for autonomous collision avoidance considering cylindrical safety bubble

Abstract

This paper presents an innovative 3D analytical algorithm for the resolution of the pair-wise noncooperative collision avoidance problem between aircrafts. The proposed algorithm addresses the above described problem by using an innovative approach, based on the consideration of a cylindrical safety bubble, and it is able to obtain an optimal three-dimensional analytical solution for this problem. This novel approach allows different minimum separations on the vertical and horizontal planes with respect to the nominal trajectory to be achieved, so minimizing the impact of the collision avoidance maneuver on surrounding traffic. Moreover, the algorithm has the very interesting feature that it does not require the solution of any non deterministic and/or iterative problem, resulting suitable for real-time applications. This is due to the capability of the algorithm to find a closed form solution for the kinematic optimization problem here considered. The solution of the collision avoidance problem requires the simultaneous change of all control variables (speed module, track and slope angles), aiming to assure the required safety level and, at the same time, to minimize aircraft deviation from the nominal trajectory. This system is mainly developed for unmanned aircraft vehicles, where high levels of autonomy (i.e. the avoidance maneuver is autonomously executed by a standard autopilot) are required, but it can also be used, as aid to pilots, in manned commercial aircrafts. The effectiveness of the algorithm is evaluated by means of numerical simulations, where suitable conflict scenarios, taking into account aircraft dynamics and on-board sensors errors and limitations, are considered. Scenarios where both aircrafts are equipped with the proposed collision avoidance algorithm or where both aircrafts are subjected to Visual Flight Rules are also considered. 1 2

UAV Collision Avoidance and Path Planning in Commercial Airspace

“…al. 16 proposed a simplified approach to the collision avoidance problem, expanding upon the 3D geometric approach proposed by Carbone et. al.…”

“…al. 16 proposed a velocity path planning algorithm which also takes into consideration uncertainties from sensors. This was undertaken for a 2D plane, proving to be adequate with multiple aircraft keeping a minimum separation distance between them.…”

“…al. describes the development of a CAS algorithm, generating an optimal path in three-dimensional space 16 . The aim proposed in the algorithm is to avoid the safety bubble surrounding the aircraft, whilst minimizing the speed vector variation, such that the aircraft does not deviate from its intended target.…”

UAV Autonomous Collision Avoidance Method Based on Three-dimensional Dynamic Collision Region Model and Interfered Fluid Dynamical System

“…And intruder is modeled as a sphere with radius R (considered as safety bubble). Luongo et al [4] proposed an analytical algorithm for collision avoidance based on the consideration of a cylindrical safety bubble. With the choice of specified values for cylinder geometric dimensions, the cylinder is used to require on autopilot command rate and maneuver settling time.…”

Worst-case analysis of moving obstacle avoidance systems for unmanned vehicles

“…Having an acceptable safe margin during all the operation conditions is a widely used criterion to assess the safety of a moving vehicle. This essentially creates a safety bubble around a moving vehicle [8]. So it is nature and intuitive to select the minimum distance between the vehicle and any moving obstacle during all maneuvers including collision avoidance for the performance assessment.…”