Aircraft Brake Torque Distribution by Disc Stack Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aircraft brakes exhibit heterogeneous braking energy distribution leading to overheating and wear, with some brakes reaching critical temperatures, necessitating waiting periods before subsequent rotations, resulting in operational inefficiencies for airlines.
Innovation Solution
A method for distributing braking torque between aircraft wheels based on the thickness of disc stacks, where individual braking setpoints are adjusted proportionally to disc thickness to ensure even heating, using electromechanical brake actuators to measure disc stack thickness and calculate distribution coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If identical braking setpoints are applied to all brakes, then the braking control is simple, but heterogeneous braking energy distribution occurs leading to overheating and wear of certain brakes
Solution Approach 1:
The patent applies local quality by distributing braking torque according to the individual state of each brake. Specifically, brakes with greater disc thickness receive higher braking torque setpoints, while brakes with thinner discs receive reduced torque. This localized adjustment ensures that each brake dissipates energy proportionally to its thermal mass, preventing overheating of specific brakes while maintaining overall effective braking control.
2Temperature
If brakes are allowed to cool down completely before next rotation, then overheating is avoided, but operational time is lost due to waiting periods
Solution Approach 1:
The patent implements preliminary action by measuring the thickness of each brake disc stack before the braking operation and using this information to pre-calculate the optimal braking torque distribution. This advance preparation allows the system to distribute braking energy evenly across all brakes from the start, preventing any single brake from overheating during the operation, thereby eliminating the need for post-braking cooling wait times before the next rotation.
3Device complexity
If braking torque is distributed evenly among all brakes, then the control system is simple, but heterogeneous disc wear leads to uneven heating and potential overheating
Solution Approach 1:
The patent employs feedback by continuously monitoring the thickness of each brake disc stack and using this measured information to adjust the braking torque distribution. The system calculates individual braking setpoints based on the feedback from disc thickness measurements, ensuring that each brake receives torque proportional to its remaining disc mass. This feedback mechanism maintains reliable and balanced thermal behavior across all brakes without requiring overly complex control algorithms.
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 method prevents significant overheating by ensuring all disc stacks heat evenly, reducing wear and allowing for immediate subsequent rotations by distributing braking energy according to disc thickness, thereby enhancing operational efficiency and reducing downtime.
Implementation Method 1
it suffices to use the electromechanical brake actuators to measure the thickness of the stacks of discs. To this end, it suffices, for example in flight before landing, to bring the pusher of one of the electromechanical actuators into contact with the discs. The position of the pusher is then noted, and the residual thickness of the stack of discs is deduced therefrom.
Implementation Method 2
We know that the energy to be dissipated by each brake is proportional to the torque developed by this brake during braking, while the heating of the corresponding stack of discs is proportional to the mass of the material constituting the discs, and therefore to its thickness.
Data Source
AI summary
The invention relates to a method of distributing braking energy between a group of braked wheels numbered 1...p and carried by N landing gear of an aircraft, each braked wheel having a brake equipped with a stack of discs on which a force is selectively applied to generate a braking torque of the wheel, each brake being equipped with means for measuring a thickness of the stack of discs, and in which: - the individual braking command to be generated by brake j is assigned the command C1=E1E1+E2.CgC2=E2E1+E2.Cg Where p is the number of wheels concerned, C is the general braking command to be developed by the braked wheels of the same landing gear, Ej is the thickness of the stack of discs of the brake of wheel j, and Cj the individual braking command for wheel j; - each brake is controlled according to the individual braking command thus determined.