Aircraft Steering Angle Warning System Using RVDT

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Solution Overview

Problem

Existing steering angle warning systems for aircraft are ineffective due to factors like poor visibility and driver distraction, and require complex setups or calibration specific to the towing vehicle and aircraft model, making them unreliable and difficult to implement.

Innovation Solution

A steering angle warning system comprising a rotation-measuring unit on the aircraft that outputs a signal based on the steering angle, triggering an alarm when the angle exceeds a predetermined value, which can be integrated with existing aircraft systems and does not require modifications to the towing vehicle, using a Rotary Variable Differential Transducer (RVDT) and a comparator unit to generate audible or visible alarms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If coloured markings alignment system is used, then visual warning is provided, but effectiveness deteriorates due to poor visibility and driver distraction

Engineering Contradiction:

Improvewarning effectivenessVSAvoidpoor visibility and driver distraction

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical visual marking system with an electronic sensor-based detection system. Ultrasonic sensors mounted on the towing vehicle detect the position of the aircraft nose gear and generate electronic warnings, substituting passive mechanical markings with active electronic detection and warning mechanisms that are not affected by visibility conditions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces ultrasonic sensors as an intermediary between the nose gear position and the warning system. The sensors detect the position indirectly by measuring distance to the aircraft structure, providing a reliable signal that is not directly affected by visual conditions, and translate this into audible or visual warnings for the operator.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If ultrasonic sensor system is used, then steering angle detection is achieved, but system complexity increases and requires specifically designed tractor

Engineering Contradiction:

Improvesteering angle detectionVSAvoidsystem complexity and tractor design requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent designs the ultrasonic sensor system to be universally applicable to different aircraft models and towing vehicle types. The sensors are mounted on standard towing vehicle locations and detect aircraft-specific reflectors, allowing the same basic system architecture to serve multiple aircraft types without requiring completely redesigned specialized vehicles for each aircraft model.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

Instead of mounting sensors on the aircraft and detecting signals from the towing vehicle, the patent inverts the approach by mounting sensors on the towing vehicle and detecting signals reflected from the aircraft structure. This inversion simplifies the towing vehicle integration and allows the aircraft to remain relatively unchanged.

Inventive Principle:

Principle #13The other way round (Inversion)

3Reliability

If reflected signal detection is used, then steering angle monitoring is achieved, but reliability deteriorates due to dirt or foreign objects on detector

Engineering Contradiction:

Improvesteering angle monitoringVSAvoiddirt or foreign objects on detector

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent uses reflectors mounted on the aircraft that create a known, controlled reflection pattern for the ultrasonic sensors. Instead of relying on the unpredictable reflection from the aircraft body surface (which may be contaminated), the system uses dedicated reflector elements that maintain consistent acoustic reflection properties, effectively creating a clean, controlled signal source that is less susceptible to contamination effects.

Inventive Principle:

Principle #26Copying

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

Provides a simple, reliable, and effective warning of excessive steering angles, preventing damage to the nose landing gear, independent of the towing vehicle type and model, with alarms visible and audible to the towing crew, ensuring safety during ground maneuvers.

Implementation Method 1

using a Rotary Variable Differential Transducer (RVDT) and a comparator unit to generate audible or visible alarms

Methodology Applied

Scientific EffectRotary Variable Differential Transducer (RVDT):

Data Source

PatentUS8094042B2Aircraft steering angle warning system

Publication Date: 2012.01.10 AIRBUS OPERATIONS LTD

AI summary

A steering angle warning system comprising a rotation-measuring unit located on an aircraft, and an alarm unit. The rotation-measuring unit is arranged to output a first signal dependent on the steering angle between a nose landing gear of the aircraft and the longitudinal axis of the aircraft fuselage. The alarm unit is arranged to generate an alarm, in dependence on the first signal, when the steering angle is greater than a predetermined value, for example, 60 degrees. The rotation-measuring unit may also be arranged to perform a function in relation to an aircraft steering system, for example to indicate the steering angle to the pilot during ground manoeuvres.