Free flight separation assurance using distributed algorithms

Many of the nation's airspace users desire more freedom in selecting and modifying their routes. This desire has been expressed in the free flight concept, which has gained increased attention in the last few years. Free flight offers the potential for more efficient routes, decreased fuel costs, and less dependence on air traffic control. The greatest challenge, however, is maintaining the safe separation between aircraft. This problem is often referred to as conflict detection and resolution (CD and R). This paper describes a technique by which aircraft may simultaneously and independently determine collision-free flight operational environment. The technique derived from potential-field has demonstrated tremendous robustness in of scenarios ranging from simple two-aircraft conflicts and contrived geometric formations to complex, randomized multi-aircraft conflicts. Communication failures and restrictive maneuverability constraints have also been considered. The results of this work suggest that potential field algorithms are an extremely robust solution to the problem of CD and R. The results also show that these algorithms can be adapted to a situation requiring distributed computation and resolution. The advantage of a distributed approach is the decreased reliance on a central command authority.