Aircraft Landing Gear Control System Redundancy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current landing gear extension and retraction systems in aircraft require multiple sequential steps, including avionics side changeovers, which increase the time the landing gear is exposed, leading to drag and reduced efficiency.
Innovation Solution
A control system with two independent processing modules that reorder the steps for retracting and extending the landing gear, performing the avionics side changeover only after the landing gear has been retracted or extended, respectively, to minimize exposure time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the avionics side changeover is performed before landing gear retraction is complete, then control redundancy is maintained, but the time the landing gear remains deployed increases
Solution Approach 1:
The system performs the avionics side changeover after the landing gear retraction is already complete, rather than before. This preliminary completion of the retraction operation allows the control switch to occur without delaying the gear retraction, thereby reducing the time the gear remains deployed while still maintaining control redundancy through the sequential switching process
Solution Approach 2:
The patent inverts the conventional sequence by completing the landing gear retraction first and then performing the avionics side changeover. This reversal of the traditional order (where control switching would occur before retraction completion) allows the system to prioritize minimizing gear deployment time while still ensuring control redundancy is established through the subsequent switching operation
2Loss of energy
If the landing gear is retracted quickly, then drag is reduced and fuel efficiency improves, but the sequence of control steps must be optimized
Solution Approach 1:
The control system is pre-programmed with the optimized sequence that completes retraction operations before performing avionics side changes. This preliminary configuration of the control logic allows the system to automatically execute the time-optimal sequence without requiring real-time complex decision-making, thereby reducing fuel consumption through faster retraction while managing control complexity through pre-planned sequencing
Solution Approach 2:
The system dynamically adjusts the control sequence execution by prioritizing retraction completion over control switching timing. The control modules coordinate their operations dynamically to minimize the overall retraction time, allowing the landing gear to be retracted as quickly as possible while still maintaining the necessary control redundancy through subsequent avionics switching
3Reliability
If multiple sequential steps are performed for landing gear retraction, then safety and reliability are enhanced, but the total retraction time increases
Solution Approach 1:
The system performs critical retraction steps before avionics side changes, ensuring that the landing gear is already in the process of retraction or has completed retraction before control switching occurs. This preliminary execution of retraction-critical steps maintains safety and reliability while minimizing the time the gear remains deployed during control transitions
Solution Approach 2:
The patent inverts the traditional approach by completing retraction operations first and then performing control switching, rather than switching controls before retraction is complete. This reversal allows all necessary safety and reliability checks to be performed during the retraction process itself, with control redundancy established afterward, thereby reducing overall retraction time while maintaining enhanced safety
Data Source
AI summary
A control system has first and second processing modules for controlling retraction and extension of an aircraft landing gear assembly. The processing modules operate independently providing redundancy. Each processing module is configured to perform a first sequence of steps for retracting the landing gear assembly and a second sequence of steps for extending the landing gear assembly. A step of switching control from one processing module to the other (e.g. an avionics side changeover step) is performed (a) as part of the first sequence of steps, but only after the landing gear assembly has been retracted, or (b) as part of the second sequence of steps. By ensuring that the step of switching control is performed at such times, and not for example between initiation of the first sequence of steps and the retraction of the landing gear assembly, the landing gear assembly may be retracted sooner after such initiation.