Horizontal Situation Indicator RNP EPU Graphical Display

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Solution Overview

Problem

Conventional aircraft display systems do not provide a highly intuitive representation of required navigation performance (RNP) and estimated position uncertainty (EPU) values, which are crucial for safe flight operations.

Innovation Solution

An aircraft display system that includes a processor and display device, rendering a horizontal situation indicator with graphical representations of RNP boundaries and EPU, using line segments separated by a distance proportional to EPU, and additional graphics for lateral deviation and corrective actions when deviations occur.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional aircraft display systems display RNP and EPU values numerically, then the information is provided to the flight crew, but the display is not highly intuitive and requires more cognitive processing

Engineering Contradiction:
Improveintuitiveness of displayVSAvoidclarity of navigation status
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

The patent creates visual copies of the RNP corridor and EPU concept on the HSI display. Instead of showing numerical values, the system renders graphical representations including RNP boundary lines, aircraft position symbols, and EPU arcs that mirror the actual spatial relationships in three-dimensional space onto the two-dimensional display, making the navigation status immediately intuitive

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent transforms three-dimensional navigation concepts (RNP corridor in space, EPU spherical volume) into two-dimensional graphical representations on the HSI display. The EPU is displayed as an arc whose dimensions represent the uncertainty volume, and RNP boundaries are shown as lines defining the corridor, converting spatial dimensions into visual dimensions that are intuitively comprehensible

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If the system provides detailed numerical RNP and EPU data, then precise navigation information is available, but the display complexity increases and reduces situational awareness

Engineering Contradiction:
Improveprecision of navigation dataVSAvoidcomplexity of display
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the essential spatial and dimensional characteristics of RNP and EPU data from the numerical values. Instead of displaying all numerical parameters, the system extracts and visualizes only the critical geometric relationships - the RNP corridor boundaries, aircraft position relative to these boundaries, and the EPU arc representing uncertainty - thereby maintaining precision while reducing display complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter representation from numerical values to visual dimensions. The EPU value is transformed into an arc with specific angular and radial dimensions, and the RNP value is transformed into boundary line positions. This parameter transformation maintains the precision of the original data while presenting it in a less complex visual format

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2175242B1System for displaying required navigation performance on a horizontal situation indicator
Publication Date: 2018.05.02 HONEYWELL INTERNATIONAL INC
  • EP2175242B1 patent drawingFigure 1~2
  • EP2175242B1 patent drawingFigure 3~4
  • EP2175242B1 patent drawingFigure 5~6

AI summary

A display system is provided that renders a horizontal situation indicator that includes required navigation performance (RNP) and estimated position uncertainty (EPU) values rendered non-numerically and in a fairly intuitive manner. A processor receives at least data representative of a desired course of the aircraft, data representative of the RNP for the aircraft, and data representative of the EPU for the aircraft. The processor renders, on a display device, a horizontal situation indicator that includes an aircraft symbol representative of a top-down view of the aircraft, an RNP boundary graphic representative of at least one RNP boundary for the aircraft, and an EPU graphic representative of the EPU for the aircraft. The aircraft symbol is rendered at a position that is representative of actual aircraft position relative to the desired course, and the RNP boundary graphic is rendered at a position relative to the rendered aircraft symbol.