Towards a Formal Language for the Common Description of Aircraft Intent

Applications of Formal Languages to Management of Manned and Unmanned Aircraft

“…In fact, according to this definition, the flight intent is a completely defined 4D trajectory, which also doesn't match with the definition of intent given at the beginning of this chapter. It has also been argued that this definition requires an operational concept very different from today's modes of operation, and not applicable in the short to medium term future [47]. Alternatively, as defined in [16,46,53], the flight intent is 'a description of the key operational requirements and constraints that must be fulfilled by the computed trajectory (e.g., intended route, operator preferences, standard operational procedures, ATC constraints, etc.…”

“…In an effort to achieve consistency between disparate trajectory predictors, having an standardized method to express aircraft intent information -i.e., the input to the trajectory computation process-became a key objective [47]. This led to the development by BR&TE of the aircraft intent description language (AIDL) [15,16], a formal language derived from the generic mathematical formulation of the trajectory computation process.…”

“…The aircraft intent must be formulated in such a way that the ensuing aircraft motion is unambiguously determined'. This definition makes the aircraft intent a good candidate to become the input of the trajectory engine (i.e., to serve as the flight script or behaviour model), and an effort to develop a common standard for sharing aircraft intent [47] concluded with the development of the aircraft intent description language (AIDL).…”

“…However, it also makes the resulting definition of the AIDL highly dependant on the aircraft motion model (AMM), that is, the set of equations describing the aircraft motion. The AIDL developed in [15,16,47] was designed to describe trajectories of commercial fixed-wing aircraft, and therefore it cannot be used for describing trajectories of other types of aircraft, such as vertical take-off and landing (VTOL) fixedwing aircraft, helicopters, or multirotors. For clarity, the AIDL derived from the equations of motion of a commercial fixed-wing aircraft will be hereafter referred to as the fixed-wing AIDL (FW-AIDL).…”

“…The AIDL [15,16,47,48] is a formal language developed by BR&TE to describe aircraft intent information. This language was designed to be generic, so it can describe any aircraft behaviour that is meaningful in ATM, and rigorous, so that a behaviour described in this language is consistent and unambiguous.…”