Aircraft Flight Control for Multiple Time Constraints
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Solution Overview
Problem
Conventional Required Time of Arrival (RTA) functions for aircraft cannot independently control cruise and descent speeds to meet multiple time constraints at different waypoints, leading to inefficient trajectory predictions and potential time deviations.
Innovation Solution
A method that calculates a single trajectory by independently varying cruise and descent speeds to satisfy multiple required times of arrival at different waypoints, using maps and isocontours to find optimal Mach and Calibrated Air Speed combinations within aircraft speed limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional RTA function iterates over Cost Index which couples Mach and CAS variations, then the system maintains a unique Mach/CAS combination, but the system cannot independently control cruise and descent speeds to meet multiple time constraints
Solution Approach 1:
The patent segments the speed control into two independent loops: an outer loop that determines cruise Mach number based on RTA constraints, and an inner loop that determines descent CAS based on energy management. This segmentation allows independent optimization of each phase while maintaining overall trajectory accuracy, resolving the contradiction between meeting multiple time constraints and maintaining system simplicity.
Solution Approach 2:
The patent implements dynamic coupling between cruise and descent phases through energy management principles. The descent CAS is dynamically adjusted based on the energy state established during cruise, allowing the system to adapt to varying RTA constraints at different waypoints while maintaining a manageable control structure that doesn't require full independence of all parameters.
2Manufacturing precision
If the system calculates multiple trajectories for each intermediate waypoint, then each trajectory segment meets its corresponding RTA, but the computational requirements and number of speed changes increase
Solution Approach 1:
The patent performs preliminary determination of the cruise Mach number in the outer loop based on RTA constraints at intermediate waypoints. This preliminary action establishes the energy state and speed profile for the entire cruise-descent operation, allowing the inner loop to focus only on descent CAS adjustment. This approach ensures trajectory accuracy while reducing computational burden by avoiding the need to calculate multiple complete trajectories.
Solution Approach 2:
The patent maintains continuous trajectory prediction by establishing a unified cruise-descent profile from the outset. The energy management approach ensures that the trajectory evolves continuously from cruise through descent, avoiding discontinuous recalculations at each waypoint. This continuous action maintains precision while improving computational efficiency by eliminating the need to recalculate entire trajectories for each intermediate point.
3Measurement precision
If the RTA function predicts trajectory with coupled Mach and CAS variations, then the system follows conventional energy management, but the system cannot optimize arrival times at multiple waypoints independently
Solution Approach 1:
The patent introduces dynamic coupling between cruise and descent phases through energy management principles. The descent CAS is dynamically adjusted based on the energy state established during cruise, allowing the system to adapt to varying RTA constraints at different waypoints while maintaining a manageable control structure that doesn't require full independence of all parameters.
Data Source
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AI summary
The invention discloses a method and a system for controlling the flight of an aircraft subjected to at least two required time of arrival constraints. It comprises receiving at least two required time of arrivals (RTAn), each required time of arrival (RTAn) at a corresponding target waypoint (WPTn) wherein at least one target waypoint is located in a descent phase of the flight; determining a set of cruise/descent speed pairs for each one of the RTA wherein each pair satisfies the corresponding RTAn at the corresponding WPTn, the cruise speed and descent speed of each pair being calculated independently from each other; selecting a single cruise/descent speed pair existing in each one of the sets of cruise/descent speed pairs; and determining a single aircraft trajectory that satisfies the selected cruise/descent speed pair.