Flight Management System Rendezvous Intercept Position Calculation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing Flight Management Systems (FMS) face limitations in calculating rendezvous intercept positions, particularly when aircraft are beyond 600 nautical miles apart, on the same path, or in polar regions, due to small angle approximations and invalid spherical triangle formulas.

Innovation Solution

The method employs Sodanos equations and a numerical solution to compute rendezvous intercept positions, adjusting for time differences and using convergence checks to ensure accuracy and reduce computational iterations, allowing for rendezvous distances up to 3600 nautical miles and accurate calculations in polar regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the spherical triangle formula with small angle approximation is used to compute rendezvous intercept position, then the calculation is simple and fast, but the rendezvous distance is limited to less than 600 nautical miles

Engineering Contradiction:

Improvecalculation speedVSAvoidrendezvous distance range

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent changes the mathematical parameters from small angle approximations to exact spherical trigonometry formulas, allowing the system to handle large angles and distances up to 3600 NM while maintaining computational feasibility through iterative numerical methods

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements a dynamic iterative calculation process that adjusts the intercept position through multiple iterations, allowing the system to converge on accurate solutions for long-distance rendezvous where static approximation formulas fail

Inventive Principle:

Principle #15Dynamics

2Ease of manufacture

If the spherical triangle formula is used to compute rendezvous intercept position, then the calculation method is straightforward, but the wrong solution is computed when two aircraft are flying on the same path

Engineering Contradiction:

Improvecalculation method simplicityVSAvoidsolution accuracy

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent inverts the traditional approach by not directly calculating the intercept position from initial conditions, but rather iteratively adjusting the intercept position until the calculated arrival times match, thereby avoiding the singularity problem when aircraft are on the same path

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent implements a feedback mechanism where the calculated intercept position is validated by checking whether both aircraft arrive at the same time, and the intercept position is adjusted based on time differences until convergence is achieved, ensuring reliable solutions even for collinear configurations

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If the spherical triangle formula is used to compute rendezvous intercept position, then the calculation works for standard conditions, but no adjustment is made when the intercept position is in a polar region

Engineering Contradiction:

Improvestandard condition applicabilityVSAvoidpolar region accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent creates a universal calculation method based on exact spherical trigonometry that functions correctly across all geographic regions including polar areas, eliminating the need for separate adjustment algorithms for different geographic zones

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Measurement precision

If more computational iterations are performed to improve accuracy for long distance rendezvous, then the intercept position accuracy is improved, but the computational time increases

Engineering Contradiction:

Improveintercept position accuracyVSAvoidcomputational time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by making intelligent initial guesses for the intercept position based on geometric relationships, reducing the number of iterations needed to achieve convergence while maintaining high accuracy for long-distance rendezvous

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS7788034B2Method for determining a flight management system rendezvous intercept position

Publication Date: 2010.08.31 HONEYWELL INTERNATIONAL INC

AI summary

One popular military aircraft mission is to meet or rendezvous with another aircraft. Presently used systems have limitations in rendezvous distance, low accuracy of computed rendezvous intercept position, and wrong results in special rendezvous scenarios such in polar regions or on a collision path. The present invention makes use of a numerical algorithm to accurately compute the rendezvous interception position with a preselected tolerance/resolution. The algorithm makes no assumption of angles and uses a proven Sodanos equation to compute a distance between two points on the earth or to compute a second position away from a first position at a known distance and bearing. Using the invention, the rendezvous intercept position can be computed with greater accuracy and a further distance in any region of the globe than the prior art methods and can be used even if the aircraft are in a rendezvous or collision/chasing path.