SV-PFD Viewpoint Correction via Glide Slope Validation
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Solution Overview
Problem
Conventional cockpit display systems often experience mismatches between Synthetic Vision System (SVS) viewpoints and Glide Slope (G/S) guidance symbology during Instrument Landing System (ILS) approaches, due to inaccuracies in altitude data from barometric altimeters and GPS receivers, which can be concerning for pilots, especially in zero-visibility conditions.
Innovation Solution
A cockpit display system that utilizes validated G/S signals to selectively correct the SVS viewpoint on a Synthetic Vision Primary Flight Display (SV-PFD), by performing a G/S validation algorithm to determine the trustworthiness of received signals and updating the SVS viewpoint accordingly, and generating alerts for invalid signals or significant disparities between altitude data and G/S signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If altitude data from barometric altimeters and GPS receivers is used to determine the vertical SVS viewpoint, then the SVS viewpoint can be continuously updated, but mismatches between the SVS viewpoint and G/S guidance symbology occur due to inaccuracies in the altitude data
Solution Approach 1:
The patent introduces an intermediary validation mechanism that acts as a mediator between the altitude data sources and the SVS viewpoint determination. The system validates whether the aircraft is properly tracking the G/S beam before allowing altitude data to influence the SVS viewpoint. This intermediary check ensures that only reliable altitude measurements (those taken during proper G/S tracking) are used, thereby resolving the contradiction between continuous updates and alignment accuracy.
2Measurement precision
If G/S signals are used to update the SVS viewpoint without validation, then the alignment between SVS viewpoint and G/S guidance symbology is improved, but the system may use invalid or inaccurate G/S signals leading to erroneous corrections
Solution Approach 1:
The patent applies preliminary action by performing validation checks on G/S signals before using them to update the SVS viewpoint. The system pre-conditions the use of G/S data by verifying that the aircraft is properly tracking the G/S beam and that the signals are valid. This preliminary validation ensures that only trustworthy G/S signals are used for viewpoint correction, resolving the contradiction between alignment accuracy and signal reliability.
3Speed
If the SVS viewpoint is frequently updated based on altitude data, then the display remains current with aircraft position, but disparities between the SVS viewpoint and G/S vertical deviation symbology increase due to altitude data inaccuracies
Solution Approach 1:
The patent implements feedback by continuously monitoring whether the aircraft is properly tracking the G/S beam and using this information to control the updating of the SVS viewpoint. The system provides feedback loops that check G/S tracking status and only allow viewpoint updates when proper tracking is confirmed. This feedback mechanism ensures that high update rates do not compromise vertical alignment accuracy, as updates are conditioned on valid G/S tracking.
Data Source
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AI summary
Cockpit display systems (10) and methods (80) are provided for performing Glide Slope (G/S) validation processes during Instrument Landing System (ILS) approaches. In one embodiment, the cockpit display system utilizes validated G/S signals to selectively correct the viewpoint of a Synthetic Vision System (SVS) scene generated on a Synthetic Vision Primary Flight Display (SV-FPD (22)). In such an embodiment, the cockpit display system may include an ILS receiver (30), a cockpit display device (14) on which the SV-PFD is generated, and a controller (12) coupled to the display device and to the ILS receiver. During an ILS approach, the controller selectively performs a G/S validation algorithm to determine the validity of the G/S signals received during the ILS approach. If determining that the G/S signals are valid, the controller then repeatedly updates the SVS viewpoint during the ILS approach based, at least in part, on the validated G/S signals.