As the aviation community moves toward the Next Generation Air Transportation System (NextGen), the current Traffic Alert and Collision Avoidance System (TCAS II) may become inadequate. This paper presents a novel approach to detection and resolution of air traffic conflicts in a 3-dimensional (3-D) airspace between two aircraft. The inputs to the detection algorithm are the current 3-D position and speed vector of both aircraft and a cylindrical minimum safety protection zone (PZ). For collision avoidance systems (CASs), the size of the configurable PZ can be assigned values that the Federal Aviation Administration (FAA) considers as a near mid air collision (NMAC1) incident. When available, additional inputs, such as measurement uncertainties and intruder type (e.g., manned/unmanned), can be used to alter the default protection zone. The conflict detection takes into account the 3-D encounter (e.g., closure rate, miss distance, relative converging maneuver). The resolution algorithm initially computes a set of six resolution advisories (RAs) and associated resolution alert times that ensure no violation of the protection zone. Two solutions are computed for each of the three dimensions: ground track, ground speed, and vertical speed. The initial resolution advisories (RAs) solutions take into account ownship capability (i.e., max climb/descent rate, max turn rate, max speed/stall speed) and ownship pilot response delay (e.g., autonomous vs. manual RA execution). These six solutions are subsequently down-selected in two steps: first, based on the encounter geometry, a single implicitly2 coordinated, independent solution is selected for each of the three dimensions; then, based on ownship preferences and operational considerations a final RA solution is computed.
Future airborne collision avoidance — Design principles, analysis plan and algorithm development
2009 IEEE/AIAA 28th Digital Avionics Systems Conference ; 6.E.2-1-6.E.2-17
2009-10-01
654870 byte
Conference paper
Electronic Resource
English