Beacon-Based Approach Guidance for Precise VTOL Landing

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Solution Overview

Problem

Vertical takeoff and landing (VTOL) aircraft, particularly passenger-carrying autonomous commercial VTOL aircraft, require precise guidance systems for landing that are redundant and cost-effective, with minimal reliance on complex software and ground-based infrastructure.

Innovation Solution

A beacon-based approach guidance system using a ground-based beacon that transmits a signal modulated with a pseudorandom noise (PRN) code, which is received by an antenna array on the aircraft, down-converted, and correlated with a locally generated PRN code to determine the vehicle's heading and elevation relative to the beacon, enabling precise landing without complex processors or extensive ground infrastructure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a beacon-based approach guidance system is used, then device complexity is reduced, but measurement precision may be compromised

Engineering Contradiction:

Improvesystem complexityVSAvoidpositioning precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces complex software-based guidance systems with a simplified beacon-based radio signal system. The antenna array receives modulated signals from ground beacons, and signal processing circuits determine vehicle position and orientation through correlation and phase analysis, eliminating the need for complex ground infrastructure and sophisticated software algorithms.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The system uses signal modulation parameters (pseudorandom noise codes) and antenna array geometry to encode position information. By changing the modulation scheme and utilizing phase/doppler frequency shifts of received signals, the system achieves precise positioning with minimal hardware complexity.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If redundant guidance systems are implemented, then reliability is improved, but device complexity increases

Engineering Contradiction:

Improveguidance reliabilityVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The beacon-based system serves multiple functions simultaneously: it provides primary guidance, redundant positioning verification, and backup capability. The same antenna array and signal processing circuits used for normal operation can detect signal failures and switch to alternative beacons or methods, providing built-in redundancy without requiring separate backup systems.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Measurement precision

If extensive ground infrastructure is deployed, then measurement precision is improved, but ease of manufacture deteriorates

Engineering Contradiction:

Improvelanding precisionVSAvoiddeployment ease

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts the essential guidance function from complex ground infrastructure and concentrates it into simple, standalone beacons. Each beacon independently transmits modulated signals containing position information, eliminating the need for interconnected ground stations, complex communication networks, or centralized control systems while maintaining precise positioning capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system significantly reduces complexity and cost while ensuring high reliability and ease of deployment, allowing for precise landing with minimal failure modes and interference, utilizing CDMA signals to share frequencies with other services and reject multipath signals.

Implementation Method 1

a ground-based beacon transmits a signal modulated with a pseudorandom noise (PRN) code

Methodology Applied

Scientific EffectSignal modulation: Phase Modulation

Implementation Method 2

down-converted, and correlated with a locally generated PRN code

Methodology Applied

Scientific EffectDown-conversion:

Implementation Method 3

correlating the I and Q samples to a locally generated pseudorandom code of the receiver to recover carrier signals

Methodology Applied

Scientific EffectSignal correlation:

Implementation Method 4

calculating, based on relative phase characteristics of the recovered carrier signals, a direction of arrival of the at least one signal from the beacon in a vehicle reference frame

Methodology Applied

Scientific EffectPhase difference measurement:

Implementation Method 5

utilizing CDMA signals to share frequencies with other services and reject multipath signals

Methodology Applied

Scientific EffectCode division multiple access:

Data Source

PatentUS20250306158A1Beacon-based approach guidance system

Publication Date: 2025.10.02 THE BOEING CO

AI summary

A beacon-based approach guidance system is disclosed. A disclosed method includes digitizing at least one signal received at an antenna array of a receiver of a vehicle to digitized data streams of I and Q samples, the at least one signal received from a beacon, the at least one signal modulated with a pseudorandom code at the beacon, correlating the I and Q samples to a locally generated pseudorandom code of the receiver to recover carrier signals, and calculating, based on relative phase characteristics of the recovered carrier signals, a direction of arrival of the at least one signal from the beacon in a vehicle reference frame.