Aerospace and Electronic Systems Magazine April 2018 - 44

Simulation Modelling of Traffic Collision Avoidance System

Figure 3.

Average consuming time of function components in the encounter model (a) and submodel (b).

sesses the highest value, corresponding to the relatively complex
underlying logic.

CONCLUSION AND FUTURE WORK
Abundant operational experience has demonstrated the utility and
efficiency of TCAS, which is used as a last resort tool designed
to prevent midair collisions between aircraft. However, one must
be aware that TCAS can preclude the vast majority but not all
collision risks and the system may, marginally, induce an additional risk. At the same time, simulation studies are essential for
TCAS operations and have identified areas in which the TCAS
design and algorithms require refinement or improvement to further enhance its efficiency. The main contributions of this article
are listed below:
C

Specify the mathematical model for TCAS II algorithm with
the wind disturbance. The speed vectors of aircraft may be
variable under the influence of wind during the execution
phase, thus it should be realistically considered to improve
TCAS robustness.
Propose an encounter model of TCAS operations in the
GMAS formalism for safety assessment. The implemented model is ingeniously designed to narrow the expanded
states, and provides a better comprehension of the potential
induced secondary conflict for risk assessment by representing the cause-effect relationship of each action.
Validate the feasibility and effectiveness of the GMASbased encounter model. A three-aircraft scenario is elaborately depicted to clearly represent the different evolution
with/without wind disturbance, and quantitative measurement experiments are conducted to calculate the average
consuming time of function components.

ther improvements of correlative study would also be interesting to
extension of the TCAS protection volume. The generated results of
the proposed encounter model could constitute a database for the
proper automation contrast in actual flight, to evaluate situations in
which whether a secondary conflict exists.

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Using this technique, the geometry of the multiple aircraft scenario is representative of what actually occurs in the airspace. Fur44

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APRIL 2018

Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine April 2018