Helicopter Control System with Mechanical Override

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Solution Overview

Problem

Current control systems for helicopters, particularly those using hydraulic actuators, face issues with complexity, redundancy, and high maintenance costs, while fly-by-wire systems are expensive and lack reliability in case of electric power failure.

Innovation Solution

A control system that uses a mechanical linkage with a lever and electric position sensor to transmit pilot commands to an electromechanical actuator, providing fail-safe functionality without the need for complex hydraulic systems or redundant power sources, utilizing a jam-proof electromechanical actuator with manual override capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If hydraulic actuators are used for pilot command transmission, then force amplification is achieved, but system complexity and maintenance requirements increase

Engineering Contradiction:
Improveforce amplificationVSAvoidsystem complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The patent replaces the hydraulic system with an electromechanical actuator that uses a motor directly driving a screw mechanism. This substitution eliminates the need for hydraulic reservoirs, pumps, filters, valves, and lines, thereby reducing system complexity while maintaining the force amplification capability through the mechanical advantage of the screw drive.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the complex hydraulic subsystem from the control system, retaining only the essential mechanical linkage and electromechanical actuator components. This extraction eliminates the need for hydraulic fluid management infrastructure while preserving the force transmission function.

Inventive Principle:
Principle #2Taking out (Extraction)

2Power

If hydraulic systems are implemented, then actuator power is sufficient, but maintenance efforts increase

Engineering Contradiction:
Improveactuator powerVSAvoidmaintenance efforts
Core Design Contradiction:
PowerVSEase of repair

Solution Approach 1:

The patent substitutes the hydraulic power system with a self-contained electromechanical actuator using a motor and screw mechanism. This replacement eliminates hydraulic fluid leakage, contamination, and system degradation issues, resulting in significantly reduced maintenance requirements while maintaining adequate actuator power for rotor control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Extent of automation

If fly-by-wire systems are used, then electrical control is achieved, but reliability decreases in case of electric power failure

Engineering Contradiction:
Improveelectrical controlVSAvoidreliability
Core Design Contradiction:
Extent of automationVSReliability

Solution Approach 1:

The patent incorporates a mechanical override mechanism that provides a backup control path in case of electrical failure. The mechanical linkage from the pilot's controls can directly actuate the rotor through the screw mechanism if electrical power is lost, ensuring continuous control capability and enhancing system reliability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent introduces a mechanical intermediary path (direct mechanical linkage) that bridges the pilot's control inputs to the rotor actuation mechanism. This mechanical intermediary serves as a fail-safe backup when the electrical control system fails, ensuring that control authority remains with the pilot.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If redundant power sources are added, then reliability improves, but device complexity increases

Engineering Contradiction:
ImprovereliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of adding redundant electrical power sources, the patent provides a mechanical backup mechanism that simplifies the redundancy approach. The mechanical override path requires no additional power sources, batteries, or electrical systems, thereby improving reliability without increasing device complexity.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

This solution reduces complexity and cost by eliminating hydraulic systems and redundant power sources, ensuring reliable actuation with minimal components, while maintaining safety and reliability, and allowing manual override in case of electric power failure.

Implementation Method 1

at least one electric position sensor for said mechanical input command

Methodology Applied
Scientific EffectElectric position sensing:

Implementation Method 2

at least one controllable electromechanical actuator fed by the at least one electric power supply and controlled by the at least one electric position sensor

Methodology Applied
Scientific EffectElectromechanical conversion:

Data Source

PatentEP2415669B1Control system
Publication Date: 2015.05.13 AIRBUS HELICOPTERS DEUT GMBH
  • EP2415669B1 patent drawingFigure 1~2
  • EP2415669B1 patent drawingFigure 3
  • EP2415669B1 patent drawingFigure 4~5

AI summary

The invention relates to a control system and to a method of operating such a control system, particularly to a control system for pilot command inputs for a helicopter, with a mechanical input signal (2), at least one electric position sensor (21, 21') for said input signal (2), at least one electric power supply (25, 25') and at least one controllable, electromechanical actuator (27, 27') fed by the at least one electric power supply (25, 25') and controlled by the at least one electric position sensor (21, 21'). The mechanical input signal (2) is applied mechanically to the at least one controllable electromechanical actuator (27, 27').