Team Vision for Problem Definition PhaseTeam Plans
- Review PRP document to gain better understanding of the project requirements
- Interview customer and key stakeholders to characterize customer's requirements
- Develop use scenarios
- Create list of questions for customer
- Obtain schematics regarding old project designs and documentation
- Develop list of team values and norms for peer evaluation
- Develop project plans for the next three weeks
- Arrange site tour of Meggitt's Akron, OH facility for customer facing and research regarding hydraulic test rig
- Research aircraft brakes and possible sensors for prototype
- Developed a project statement, scenario, customer and engineering requirements based from the PRP
- Interviewed customer and a lot of questions were answered about the project
- Updated requirements and statement for a more accurate representation of the project
- Review old documents for design inspiration and evaluation
- Team values and norms were created for peer evaluations
- Project plans were created for next three weeks with a group going to visit Meggitt
Project SummaryA brake simulator is a hydro-mechanical assembly that is able to replicate the brake system of an aircraft. This simulator will mimic the brake performance of different sizes for a variety of brake assembly testing plans. The simulator must be able to integrate with other aircraft component simulators as well, such as a hydraulic rig. Brake simulators are used in order to collect accurate data without testing an actual brake assembly. The data for a simulator will be compared to physical brake test data in order to verify the simulated output.
Meggitt Aircraft Braking Systems is in need of a simulator mimic brake assembly compliance and mechanical stiffness of their braking systems. The current setup regards two components plumbed together on a table-top with brake assemblies hung off the sides. The simulator will eliminate the need for bulky assembly and physical product testing. The simulator’s control system will show the hydraulic load generated from the brake assembly, as well as permit an operator to quickly and easily modify the simulation.The operator must be able to monitor the system parameters behind a safety shield while viewing the test through a sight window. The apparatus must be maneuverable through a 32” door by a single person. Installation must require less than 30 minutes, pressure changes must occur within an 8 hour period, and air must be bled out for disconnection within (X) amount of time.The simulator must be able to operate over a range of 0 to 5000 psi and 1 million maximum pressure cycles. The final output will be a graph of volumetric displacement versus a hydraulic pressure curve.
Apparatus must comply with the following standards: NEMA, CE, SAE AS4716, SAE AS6235, SAE AS4365, SAE AS4375, SAE AIR5372 and MIL-PRF-5606 or AS1241.
- Test existing rigs used at Meggitt for calibration
- Evaluate expected performance of a particular type of aircraft brake
Project Goals and Key Deliverables
- Develop a functional prototype of the AABS system capable of operation via Meggitt's in house hydraulic rig testing setup
- Provide detailed technical manual for use
- Gather pressure-displacement curve data from AABS
|Meggitt - Kyle Berkowitz||COE Engineer|
|Meggitt PLC||Key User|
|Meggitt's Aviation Customers||Brake users\owners|
|Harold Paschal||Academic Advisor|
|MSD Team||AABS System Developers|
- Total Project Budget: $10,000
- Entirety of system must fit within a 32" door
- AABS must be able to integrate with Meggitt's brakes hydraulic testing rig - AS4375 Style-E Fitting Ends (Tube Size: OD: 0.375'')
- Must be reliable up to 1 million usage cycles
- System must be safe for user
- Setup completed within 30 minutes
- Some project elements are ITAR EAR/export control restricted
- IP data will be likely be owned by Meggitt PLC in part or whole
These constraints are elaborated and investigated through comparing engineering requirement to Meggitt's stated requirements for the AABS system below.
Customer Requirements (Needs)Meggitt has requested the AABS system to replace their existing brakes testing method. Currently brakes engineers attach non-serviceable, or otherwise unusable brakes assemblies to their hydraulic test rig. Usually, this is done for one of two cases:
- Calibration or testing of the hydraulic rig
- Evaluating expected brakes performance of a certain size brake.
As Meggitt uses only non-serviceable brake assemblies, if none are available, these tests cannot be run. Additionally, these assemblies are large, bulky and non-consistent between runs, as they are no longer in use and likely incapable of producing accurate pressure vs. displacement output.
Therefore Meggitt has attempted several prototype designs to resolve this issue. Their first design, produced in 1990, aimed to add variability to the simulator. Though never fully developed, this prototype was capable of replicating various brakes designs by having a set of spring disks swapped at the engineer's request.
Prototype c. 2017 to mimic mid-sized Business Jet Brake. Similarly, spring disks were used to mimic brakes performance when hydraulic pressure is applied. However, this design was only useful for mid-sized brakes assemblies, and thus not addressing Meggitt's need for a universal simulator, and example of a high cost, low value functional prototype.
In response to this state, the following are Meggitt PLC's general requirements as to the function and form of the AABS system.
|Type||CR||Meggitt’s Customer Requirements||CAI|
|Setup||CR 3||Quick Installation Time||3|
|CR 4||Set time to alter pressure/displacement settings||3|
|Compatibility||CR 5||Configure to Meggitt’s existing hydraulic lines||5|
|CR 6||Compatible with common aircraft brake fluids||5|
|Safety||CR 7||Safe for user||5|
|CR 8||Consistent with existing US and European regulation||5|
|Function||CR 9||Easily Configurable to various brake specs||5|
|CR 10||Pistons & Rod Seals Specs Standardized||5|
|CR 11||Easily free the system of air||4|
|CR 12||Design to any Displacement vs. Pressure curve||5|
|CR 13||Ability to tune fill rate||5|
|CR 14||Reliable and accurate||5|
|CR 15||Long term usage||4|
|CR 16||Ability to maintain and repair||5|
|CR 17||Resistance to indoor environment/hydraulic fluids||5|
|Interface||CR 18||Uses commercially Available Software||1|
|IP Concerns||CR 19||Limited IP in development||1|
Note: Upon visit to Meggitt, Kyle suggested 'Priority' be represent in a more defined manner, thus the team implemented the Customer Applicability Index (CAI). This scales the customer ratings from 1 to 5, with 5 being most critical.
Engineering Requirements (Metrics & Specifications)Engineering requirements for the development of the AABS system were determined through interpretation of Meggitt's prescribed customer requirements, as well as email correspondence and a customer interview with Kyle Berkowitz and Ankit Prasad, engineers at Meggitt working with the team to develop the brake assembly simulator.
|Type||ER||Source||AABS Engineering Requirements||Unit||Ideal||Marginal||Improvement||Test|
|Footprint||ER 1||CR 1, CR 2||Max width of 32"||in||28||32||minimize||tape measure|
|ER 2||CR 1, CR 2||Weigh less than 100 lbs||lbs||80||60||minimize||NIOSH compliant|
|Setup||ER 3||CR 3, CR 9||Setup modification complete within 30 minutes||minutes||15||30||minimize||timer|
|ER 4||CR 3, CR 4||8 hours to fully configure AABS||hour||1||4||minimize||timer|
|ER 5||CR 5, CR 12, CR 14||Common set-up parameters result in consistent output||curve error||100%||95%||maximize||curve error|
|Safety||ER 6||CR 5, CR 7, CR 15, CR 16||No pinch points||count||0||0||minimize||visual check|
|ER 7||CR 7, CR 8||NEMA & CE compliant||Y/N||compliant||compliant||X||Read guidelines|
|ER 8||CR 5, CR 7, CR 8, CR 10, CR 15||AS4716 Compliant; O-Ring and Gland Spec||Y/N||compliant||compliant||X||Read guidelines|
|ER 9||CR 5, CR 7, CR 8, CR 10, CR 15||AS6235 Compliant; O-Ring and Gland Spec||Y/N||compliant||compliant||X||Read guidelines|
|ER 10||CR 7, CR 16||Protective shield must contain all potential shrapnel||count||0||0||minimize||visual check|
|Rig Compatibility||ER 11||CR 5, CR 7, CR 10||AS4375 Style-E Fitting Ends (Tube Size: OD: 0.375'')||Y/N||compliant||compliant||X||Read guidelines|
|ER 12||CR 5, CR 6||Capable of using Red Oil; MIL-PRF-5606||Y/N||Y||Y||X||system compatibility|
|ER 13||CR 5, CR 6||Capable of using Phosphate Ester: AS1241||Y/N||Y||Y||X||system compatibility|
|ER 14||CR 3, CR 5, CR 7, CR 13||Hydraulic inlet must have 0.052’’ restrictor||in||0.052"||0.052"||ideal||caliper|
|Function||ER 15||CR 7, CR 11, CR 14, CR 15||Must bleed the system of air within 5 minutes||minutes||1||5||minimize||timer|
|ER 16||CR 5, CR 9, CR 12, CR 13||Reach max pressure of 5000 psi||psi||4500||5000||maximize range||pressure transducer|
|ER 17||CR 14, CR 15||Accelerated Life Testing Predict 1M Pressure Cycles||count||1 M||1 M||maximize||Accel. Life Cycle Test|
|Structure||ER 18||CR 7, CR 14, CR 15, CR 16, CR 17||Components made of SAE/MIL Spec Materials||Y/N||Y||Y||X||design to ER|
|ER 19||CR 7, CR 8, CR 14, CR 15||Minimum Factor of Safety of 1.2||[-]||1.5||1.2||maximize||ANSYS|
|Interface||CR 20||CR17||Utilize C based architecture (MATLAB, Python)||Y/N||Y||Y||X||design to ER|
The National Institute for Occupational Safety and Health (NIOSH) is a division of the Centers for Disease Control and Prevention (CDC)
House of QualityThe HOQ evaluates the congruence between Meggitt's proposed requirements and the team's derived engineering requirements as gathered from the aforementioned CR's. As such, by evaluating the relationship between ERs and CRs for the AABS project, relative weighting is applied to each engineering requirement:
Image derived from: House_of_Quality.xlsx
From this, ERs can be sorted via relevance to the project.
|Weight||Engineering Requirement||ER No.|
|8.33%||Components made of SAE/MIL Spec Materials||ER 18|
|8.06%||AS4716 Compliant; O-Ring and Gland Spec||ER 8|
|8.06%||AS6235 Compliant; O-Ring and Gland Spec Y||ER 9|
|7.05%||Reach max pressure of 5000 psi||ER 16|
|6.87%||Minimum Factor of Safety of 1.5||ER 19|
|6.59%||Must bleed the system of air within 5 minutes||ER 15|
|6.50%||No pinch points||ER 6|
|6.50%||Hydraulic inlet must have 0.052’’ restrictor||ER 14|
|5.95%||AS4375 Style-E Fitting Ends (Tube Size: OD: 0.375'')||ER 11|
|4.58%||Capable of using Red Oil; MIL-PRF-5606||ER 12|
|4.58%||Capable of using Phosphate Ester (Skydrol): AS1241||ER 13|
|4.12%||1 million max pressure cycles||ER 2|
|4.12%||Weight less than 100 lbs||ER 5|
|4.12%||Accelerated Life Testing Predict 1M Pressure Cycles||ER 17|
|3.66%||NEMA & CE compliant||ER 7|
|3.39%||Protective shield must contain all potential shrapnel||ER 10|
|3.21%||Maximum width of 32"||ER 1|
|2.75%||Setup modification complete within 30 minutes||ER 3|
|1.10%||8 hours to fully configure AABS||ER 4|
|0.46%||Utilizes C based architecture (MATLAB, Python)||ER 20|
From the table shown above it is evident that high level system characteristics, such as max psi level, hydraulic fitting requirements and safety features, such as the bleed air system, are weighted relatively higher than items such as configuration time and IP specifics.
Outputs and DestinationFor P18371 and our AABS system project, stored data can be found in the Problem Definition Documents directory.
Provide input to the risk management process.
Design Review MaterialsDesign Review: The Problem Definition Review PowerPoint as presented 01/30/2018. The CR, ER, HOQ, Preliminary Schedule, and Risk Management charts from the powerpoint were printed for audience handouts.
Plans for next phase
Individual and group actions towards the next phase will be specified once the team meets with the sponsor 2/16/2018 in Akron, OH.