Design and Evaluation of a Dynamic Programming Flight Routing Algorithm Using the Convective Weather Avoidance Model

Abstract

The optimization of traffic flows in congested airspace with varying convective weather is a challenging problem. One approach is to generate shortest routes between origins and destinations while meeting airspace capacity constraint in the presence of uncertainties, such as weather and airspace demand. This study focuses on development of an optimal flight path search algorithm that optimizes national airspace system throughput and efficiency in the presence of uncertainties. The algorithm is based on dynamic programming and utilizes the predicted probability that an aircraft will deviate around convective weather. It is shown that the running time of the algorithm increases linearly with the total number of links between all stages. The optimal routes minimize a combination of fuel cost and expected cost of route deviation due to convective weather. They are considered as alternatives to the set of coded departure routes which are predefined by FAA to reroute pre-departure flights around weather or air traffic constraints. A formula, which calculates predicted probability of deviation from a given flight path, is also derived. The predicted probability of deviation is calculated for all path candidates. Routes with the best probability are selected as optimal. The predicted probability of deviation serves as a computable measure of reliability in pre-departure rerouting. The algorithm can also be extended to automatically adjust its design parameters to satisfy the desired level of reliability.

Automated Flight Routing Using Stochastic Dynamic Programming

“…A previous study 6 develops the formula that uses all CWAM fields along the flight trajectory to calculate the probability of deviation from the given flight path. Assuming deviation events occur only when weather forecasts are updated and the events are independent, the formula is as follows: …”

“…Figure 4 summarizes the experimental setup. The wind magnitude is assumed to be zero when calculating SDP routes because the DDP algorithm 6 neglects the effect of winds. This part of study also assumes no airspace congestion.…”

“…6 The weather-avoidance routes are generated using actual and forecasted weather data from CWAM. The DDP algorithm, which is similar to many other weather avoidance algorithms, determines the routes that avoid only convective weather systems (e.g.…”

“…Previous work 6 that constructs the grids and groups them into stages shows that the optimal path is obtained in linear time. This study adapts the same procedure and also obtains the optimal path in linear time.…”

“…Several rerouting algorithms [1][2][3][4][5][6] that utilize weather forecast have been developed in recent years. The studies in Refs.1-2 reduce the optimal routing problem to a shortest path search.…”