Aircraft Backup Control via Engine Thrust Modulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircrafts face challenges in controlling attitude and heading when hydraulic systems fail, as relying on engine thrust requires substantial pilot skill and can result in undesirable changes, especially for unstable aircraft with fly-by-wire control augmentation.
Innovation Solution
A backup control system uses conventional cockpit interfaces to modulate engine thrust, rescaling digital fly-by-wire gains to control pitch, roll, and yaw, allowing control without altering piloting techniques, and providing feedback for engine state and auto-throttle adjustments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If engine thrust is used to control aircraft attitude and heading after hydraulic system failure, then the aircraft can still be controlled, but the control becomes difficult and requires substantial pilot skill
Solution Approach 1:
The patent introduces an intermediary control system that translates conventional cockpit control inputs (yoke, rudder pedals) into appropriate engine thrust commands. This intermediary layer masks the complexity of direct thrust control, allowing pilots to use familiar control techniques while the system handles the complex mapping to thrust adjustments for attitude and heading control.
Solution Approach 2:
The patent replaces the mechanical hydraulic control system with an electronic control system that modulates engine thrust. Instead of using hydraulic pressure to move control surfaces, the system uses electronic signals to adjust engine thrust, thereby controlling aircraft attitude and heading through thrust vectoring rather than mechanical surface movement.
2Ease of operation
If conventional cockpit interfaces are used to control engine thrust directly, then the interface remains familiar, but the control responses become counterintuitive and ineffective
Solution Approach 1:
The control system acts as an intelligent intermediary that receives inputs from conventional cockpit interfaces and translates them into effective thrust commands. The system understands the intended pilot action and compensates for the different dynamics of thrust-based control versus traditional control surface control, maintaining intuitive response characteristics.
Solution Approach 2:
The system dynamically adjusts control parameters and gain schedules based on flight conditions to optimize the mapping between cockpit inputs and thrust responses. This allows the familiar interface to produce effective control responses across different flight regimes despite the fundamentally different control mechanism.
3Reliability
If hydraulic systems are made redundant to improve reliability, then control capability is maintained, but the system complexity and cost increase
Solution Approach 1:
The patent extracts the essential control function from the complex hydraulic system and implements it through a simpler electronic control system that modulates engine thrust. By taking out the core attitude and heading control capability and implementing it through thrust modulation, the system eliminates the need for complex redundant hydraulic systems while maintaining control reliability.
Solution Approach 2:
The patent makes the engine thrust system multi-functional, using it both for its primary purpose of providing propulsion and for the secondary purpose of controlling aircraft attitude and heading. This universal use of engine thrust eliminates the need for separate redundant hydraulic control systems, reducing overall system complexity.
Data Source
AI summary
A system is disclosed for controlling an aircraft when the hydraulic system of the aircraft has been compromised. The system includes a digital fly-by-wire control system configured to rescale at least one gain vector. The gain(s) may then used by a digital control to modulate engine thrust. In this manner, engine thrust modulation may be used for stabilization and control of control-configured aircraft without requiring a substantial change in piloting technique.