Human factors evaluation of conflict resolution aid in future air traffic control
Date of Issue2017-05-17
School of Mechanical and Aerospace Engineering
Air Traffic Control (ATC) safety is currently being threatened by the continuous increase in air traffic density (Airbus, 2013; Albrecht, Lee, & Pang, 2012; EUROCONTROL, 2004; ICAO, 2006, 201 O; Sheridan, 2006). The continuous increase in air traffic could potentially trigger more Loss of Separations (LOS) as current ATC systems are approaching maximum capacity and the existing A TC practices may not be able to sustain the imminent traffic growth (CANSO, 2012). As a pertinent evidence, in 2004, 2009, 2013, and 2014 there were 144, 72, 112, and 163 cases respectively of near/mid-air collisions (U.S. Department of Transportation, 2014). An automated Conflict Resolution Aid (CRA) has been proposed to be a plausible solution for providing an additional safety layer in the A TC. The automated CRA does not only have the function of detecting conflicts, but can also recommend controller maneuvers to eliminate the conflict. However, questions regarding suitable Human-Automation Interaction (HAI) procedures and safety critical issues in using the automated CRA in ATC remain to be answered (Prevot, Homola, Martin, Mercer, & Cabrall, 2012). The first unresolved question inquires about how the CRA reliability influences the application of the CRA, since automation reliability is arguably the most important issue in HAI. The second one questions how increased traffic density would influence the effects of CRA reliability on the use of the CRA. The third unresolved question asks how Vertical Situation Display (VSD) could support the application of the CRA in ATC facilities since lack of understanding regarding vertical situation has become one of the major causes of aviation accidents. This thesis therefore aims to address these questions. This thesis is comprised of three experimental studies corresponding to the three research questions raised above. Study 1 investigated the relationship between the CRA reliability and human performance variables, including task performance, workload, trust, dependence, and situation awareness. The results of Study 1 showed that reliable automation could support operators' performances. However, the present study also verified the benefit of the imperfectly reliable CRA on ATCOs' performances. Study 2 examined the interaction between the CRA reliability, traffic density, and ATCO performance variables. Study 2 supported the findings in Study 1 by showing that the novel CRA, whether perfect or imperfect, could improve ATCOs' performances. In addition, the results indicated that the greater benefits of the CRA were applicable in high traffic density conditions, answering the future ATC challenge. Study 3 investigated the effects of VSD and its integration with the CRA. The results of Study 3 empirically supported the integration of VSD into ATC facilities as indicated by positive effects of the display on ATCOs' human performance variables. In addition, providing the VSD when ATCOs work with the CRA could help offset the automation imperfection. The research theoretically describes various factors influencing ATCOs' performances with the CRA that covers automation as well as environmental aspects, including automation reliability, traffic density, and vertical situation display. Furthermore, this research provides empirical evidence regarding the relationships among the factors for the application of the CRA. Collectively, this research has high practical relevance. Results from this research provided practical implications for the development of future A TC workplaces, including conflict resolution automation and VSD for ATC facilities.