Aircraft Flight Control Transition Management for Longitudinal Attitude

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing aircraft flight control systems struggle to maintain precise longitudinal attitude during operations like air-drop while maintaining pilot sensitivity and avoiding unwanted disturbances during transitions.

Innovation Solution

A method and system that combines load factor control and longitudinal attitude control, with a transition phase to store and maintain the aircraft's longitudinal attitude, ensuring constant attitude and sensitivity, using a load factor control module and a longitudinal attitude control module with a transition management module to manage the transition between control laws.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If load factor control law is applied during manual actuation of control column, then pilot sensitivity and flight control sensation are maintained, but longitudinal attitude cannot be maintained constant during absence of pilot input

Engineering Contradiction:

Improvepilot sensitivityVSAvoidlongitudinal attitude stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The control system dynamically switches between two control laws based on pilot input state: load factor control law when control column is actuated, and longitudinal attitude control law when control column is released. This dynamic adaptation allows the system to provide appropriate control characteristics for each operational phase, maintaining pilot sensitivity during active control while ensuring attitude stability during passive phases.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the control parameter being regulated based on operational context: when pilot input is detected, the system regulates load factor (providing natural flight sensations), and when pilot input is absent, it switches to regulating longitudinal attitude (maintaining constant orientation). This parameter switching resolves the contradiction by applying the appropriate control objective for each state.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If longitudinal attitude control law is applied to maintain constant attitude during absence of pilot input, then attitude stability is improved, but transition from load factor control may cause unwanted disturbances and overshooting

Engineering Contradiction:

Improvelongitudinal attitude stabilityVSAvoidtransition disturbances

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary action by determining the current longitudinal attitude value immediately when transition to attitude control mode is initiated, before the actual switching occurs. This pre-capture of the attitude reference value ensures a smooth transition without disturbances or overshooting, as the new control law starts from a known reference state rather than abruptly changing control objectives.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The current longitudinal attitude value acts as an intermediary parameter during the transition between control laws. By capturing and storing this intermediate value, the system creates a bridge between the load factor control phase and the attitude control phase, ensuring continuous and smooth control without harmful transitions or overshooting.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If control system switches between load factor control and attitude control laws, then both pilot sensitivity and attitude maintenance are achieved, but system complexity increases due to transition management

Engineering Contradiction:

Improvecontrol law adaptabilityVSAvoidcontrol system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control system applies different control qualities to different operational phases: load factor control provides natural flight sensations during active piloting, while longitudinal attitude control provides precise attitude maintenance during passive phases. This local differentiation of control quality allows the system to be optimally adapted to each operational context without requiring complete system redesign.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10023301B2Method and system for controlling the flight of an aircraft with respect to the pitch axis

Publication Date: 2018.07.17 AIRBUS OPERATIONS (SAS)

AI summary

A system including a load factor control module for calculating a deflection order on manual actuation of a control column by a pilot of the aircraft and transmitting that deflection order to at least one elevator of the aircraft, a longitudinal attitude control module for maintaining the longitudinal attitude of the aircraft at a target attitude in the event of absence of manual actuation of the control column by the pilot during a flight, and a transition management module for determining and storing a present longitudinal attitude value of the aircraft at a recording moment and transmitting that longitudinal attitude value to the longitudinal attitude control module for the longitudinal attitude control module to use the longitudinal attitude value as the target attitude.