Aircraft Arrival Stream Optimization via Soft Separation Constraints

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Solution Overview

Problem

Existing air traffic control optimization models typically treat desired minimum time-based separation between aircraft as a hard constraint, leading to suboptimal results in terms of fuel consumption, flight time, and the need for holding procedures.

Innovation Solution

The optimization model uses the desired minimum time-based separation as a soft constraint, allowing for the determination of optimized target arrival times that consider additional optimization criteria, such as minimizing holding procedure durations and aligning with preferred overflight times.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the desired minimum time-based separation between aircraft is treated as a hard constraint, then safety separation is ensured, but fuel consumption increases and flight time extends due to required holding procedures

Engineering Contradiction:
Improvesafety separationVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention changes the parameter of separation constraint from hard to soft, allowing dynamic adjustment based on multiple optimization criteria. The cost function incorporates separation requirements as a flexible parameter rather than a rigid constraint, enabling trade-offs between separation, fuel consumption, and flight time.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces dynamic optimization by allowing the separation constraint to adapt based on real-time conditions and multiple competing objectives. The system dynamically balances separation requirements against fuel efficiency and schedule adherence through a multi-criteria cost function.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the desired minimum time-based separation between aircraft is treated as a hard constraint, then safety separation is ensured, but flight time increases due to holding procedures

Engineering Contradiction:
Improvesafety separationVSAvoidflight time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention transforms the separation constraint from a fixed hard parameter to a flexible soft parameter within the cost function, allowing the system to minimize flight time while maintaining acceptable separation levels through dynamic optimization.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically optimizes flight time by adjusting separation requirements based on overall stream optimization goals, eliminating unnecessary holding procedures while maintaining safety through the soft constraint approach.

Inventive Principle:
Principle #15Dynamics

3Productivity

If target times are allocated to aircraft to improve runway utilization, then airport capacity increases, but aircraft must be delayed to arrive at the requested time

Engineering Contradiction:
Improveairport capacityVSAvoiddelay time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The invention performs preliminary optimization of the entire aircraft stream before arrivals, calculating optimal target times that minimize total delay while maximizing runway utilization. This advance planning allows aircraft to be spaced efficiently without requiring last-minute delays.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the optimization model to adjust target times based on actual stream conditions, continuously balancing runway capacity utilization with minimal delay to aircraft.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4050584B1Method for optimizing an arrival stream of at least two aircraft, corresponding device and computer program
Publication Date: 2025.06.11 FREQUENTIS ORTHOGON GMBH
  • EP4050584B1 patent drawingFigure 1
  • EP4050584B1 patent drawingFigure 2
  • EP4050584B1 patent drawingFigure 3

AI summary

The invention relates to a method (100) for optimizing a stream of at least two aircraft (200a, 200b) forming at least one aircraft pair (202), wherein each aircraft (200a, 200b) enters a predefined environment (204), in particular an airspace (204), via an individual or common entry waypoint (206) and wherein the aircraft (200a, 200b) approach a common predefined merging waypoint (208), the method (100) comprising receiving (102) an estimated entry time (ETO) for each aircraft (200a, 200b) at the at least one entry waypoint (206), receiving (104) a target time (RTO) for each aircraft (200a, 200b) to arrive at the merging waypoint (208), wherein said target time (RTO) comprises a delay (D) to be absorbed before reaching said merging waypoint (208), receiving (106) routing information for each aircraft (200a, 200b) comprising waypoints for routing said aircraft (200a, 200b) from the entry waypoint (206) to the merging waypoint (208), wherein the waypoints comprise at least one dedicated waypoint (210) defining (108) a desired minimum time based separation (Ŝk) for each pair of aircraft (202), and determining (110) optimized target arrival times (Tk), in particular target overflight times (Tk), at the one or more dedicated waypoints (210) for the at least two aircraft (200a, b) utilizing an optimization model (214) considering the estimated entry time (ETO), the target time for each aircraft to arrive at the merging waypoint (RTO) and the desired minimum time based separation (Ŝk), wherein the optimized target arrival times (Tk) are determined such that the delay (D) to be absorbed for each aircraft (200a, 200b) is shared between route segments defined by said dedicated waypoints (210). According to the invention, it is proposed that the optimization model (214) utilizes the desired minimum time based separation (Ŝk) as a soft constraint (226).