(searched for: doi:10.2514/atcq.23.2-3.183)
Published: 27 August 2020
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, Volume 235, pp 621-645; https://doi.org/10.1177/0954410020953045
With the increasing density level of airspace, the flawed logic of resolution in air conflict has become a potential hazard to keep flight safety for civil aviation. A powerful decision-support system is needed to identify and resolve potential conflicts on planned trajectory in advance. Existing studies on this subject mainly focus on the centralized means, but seldom consider the decentralized approaches. In this paper, a decentralized method is proposed so that each aircraft can generate the collision-free Reference Business Trajectory (RBT) autonomously, and resolve potential conflicts while conforming to the unified rules. Firstly, a Synchronous Discrete-Time-Discrete-Space trajectory modeling is developed to divide the continuous planned trajectory into multiple trajectory segments according to motion state. Thus, the collision can be accurately located at one certain risky segment, and the corresponding collision time can be acquired precisely. Through a weight analysis of collision time, the critical trajectory segment is determined to implement the task of conflict resolution. Then, the Optimal Reciprocal Collision Avoidance (ORCA) algorithm is adopted and extended to determine the collision-free maneuver with the consideration of direction selectivity. At last, the Trajectory Change Points (TCPs) are achieved by the quadratic program for each aircraft. The proposed method can help aircraft generate collision-free RBT in decentralized way successfully. Several simulations are conducted to confirm the validity and efficiency of the proposed approach.
Published: 1 September 2017
2017 IEEE/AIAA 36th Digital Avionics Systems Conference (DASC) pp 1-7; https://doi.org/10.1109/dasc.2017.8102089
Testing of Detect and Avoid (DAA) systems ranges from the use of pre-defined inputs, through part-task and full mission simulations up to flight testing. Live, Virtual and Constructive (LVC) data-sources yield the same observation to a client of this data and provide the opportunity to achieve a seamless transition between the various phases of testing. The interface of a system under test is likely to change during early development stages and thus the design of the LVC environment must ensure that such changes do not propagate through the LVC environment in such a way that it unnecessarily affects other components. Modularity is the key enabler for separating functionalities that have different design-evaluation cycle times. The current state-of-the-art in software development for real-time distributed systems enables a modular approach using industry standard middleware. This paper discusses how such an LVC environment has been realized and provides an overview of its use in several flight tests of DAA systems.