Safety Separation Distance Design for UAV Formation Based on System Performance

In this article, ensuring that the distance between uncrewed aerial vehicle (UAV) formation members surpasses the safety separation distance (SSD) is paramount for flight safety. This SSD is jointly determined by the navigation and control systems. Existing studies frequently consider the performances of the two systems separately and rely on empirical designs for SSD, which can lead to inefficient use of airspace by the formation. This article presents a general framework for the SSD design in UAV formation by integrating navigation and control systems. Specifically, a filter for the integrated system is developed to reduce separation distance error and estimate their statistical characteristics. Taking the statistical characteristics of the separation distance error as a measure of the uncertainty in relative positioning, a method for calculating collision probability based on the envelope model is proposed to characterize the collision risk between formation members. Furthermore, a problem for achieving SSD that meets a specific collision risk level is formulated and optimized, guiding the design strategy of formation spacing. Simulation results validate this method effectively determines the SSD that meets flight safety requirements based on navigation and control performances, showcasing the practicality and effectiveness of our framework.