Modeling and Analysis of Conflicts between Alerting Systems

The potential for conflicting information to be transmitted by different alerting systems is growing as these systems become more pervasive in operations. Newly-introduced alerting systems must be carefully designed to minimize the potential for and impact of alerting conflicts (or dissonance), but there is little formal understanding to aid this process. One example of alert proliferation is the recently-proposed Airborne Conflict Management (ACM) system which must operate in conjunction with the existing Traffic Alert and Collision Avoidance System (TCAS). Alerts from ACM should be harmonized with alerts from TCAS and vice-versa. A model of alert dissonance is developed to provide a foundation for understanding dissonance and as a tool to identify and resolve dissonance between systems such as TCAS and ACM. Several different types of alerting dissonance are identified using a statespace representation. As a case study, dissonant operating regions for TCAS and ACM are articulated, and it is shown that TCAS advisories cannot be avoided without aggressive maneuvering following ACM alerts in some geometries. This type of analysis should be continued with higher fidelity to further refine ACM specifications.