P17341: Harris Near-Zero CTE Test Apparatus
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Gate Reviews

Table of Contents

MSD I: Readiness to move to Build & Test

Progress Report

Week 15 goal completion

Week 15 goal completion

Individual plans for the first 3 weeks of MSDII for each team member can be found here

Team Critique

Team Critique

Team Critique

Team Assessment

Team Assessment

Status Review

Mechanical / System Design Summary Final State:

The prototype design at the end of MSDI remains at 90% CAD completion, minor changes are still required. The overall design of the prototype has been decided on, but work still needs to be done on clamp designs. It was expected that the design portion would not be completed by the end of MSDI, so we are still on track.

For the mechanical system design we planned to have a nearly completed model of our prototype and clamps completed by the end of MSDI. We also wanted to do analysis on different materials in order to choose the best materials for our structure. Additionally, the plan was to ensure the overall design would be user friendly and be simple to set up and run.

At this point, these goals have been met. The current design is robust and satisfies our customer’s requirements. One area still in progress is the clamp design, creating a simple, effective clamp which will be able to hold the coupon secure. The cost of making the parts has not been evaluated but with the current parts purchased for prototype work, we have not exceeded the budget.

Electrical / Controls Summary Final State:

The goal for MSD1 with respect to the electrical/control systems was to prove that magnetic levitation is feasible. We have been able to levitate objects, thus the levitation portion of the project is feasible while staying well within budget. This was done through researching previous projects and trying to replicate results. The more difficult task is to create a stable levitation system. The difficulty and complexity of this task revealed itself once we were able to levitate.

The project has been proposed in such a way that levitation is useless unless the levitation is extremely stable. The current levitation system is unstable, so the use of subject matter experts will be required moving forward for the aid in creating a stable levitation system. This being said, the hardware and control scheme of the system could change drastically. The consultation of subject matter experts will be done as soon as possible in MSDII (Depending on the availability of the SME).

In addition to consulting subject matter experts to create a deployable system model, experimentation with additional sensors integrated into the control system will be conducted. Additional sensors may help to mitigate some of the system error. In particular, the addition of a second hall-effect sensor above the electromagnetic coil may allow for isolation of the magnetic field from the coil. This would greatly reduce the error involved with sensing the position of the target within our test fixture. These tests will be conducted at the beginning of MSDII.

Also for the final state there will have to be some sort of data acquisition module or system embedded within the system controller. This will allow for real time data logging of proximity data obtained from the cap sensor used to measure the CTE. This data logging will allow the customer to view a plot of the cap sensor data, encompassing the entire duration of the test which would effectively display the CTE of the sample material.

MSDI was successful with regards to proving that levitation is feasible, it also was very successful in the sense of, we know what problems we are going to need to tackle for MSDII. We know that there are some fundamental problems between simulations and hardware. We also know we have hardware implementation hurdles that we will want to take care of in MSDII.

Status From Client:

Mechanical Design

Overall System Design:

Current prototype design.

Current prototype design.

At the end of MSD I, the prototype design remains at 90% completion. The final 10% will come from updated clamp designs and finalizing dimensions of components.

Next steps to reach design completion:

Steps for final prototype:

Steps for Clamps:

Thermal Design

Expressions to be used for analysis

Expressions to be used for analysis

The lumped capacitance approach introduced in the previous design review will be used to model the heating system. As the apparatus is constructed and tested, it may be necessary to sophisticate the mathematical model, as some assumptions made may prove to be invalid. Additionally, the overall heat transfer coefficient UA will need to be either determined or estimated, so that an adequate dT/dt can be chosen. It is likely that further consultation with a subject matter expert will be necessary in order to adjust the model. Hands on testing will be necessary to determine if the current model is adequate or not.

Electrical Design

System Architecture
System Architecture

System Architecture

Systems:

Electrical System Design

Electrical Schematic

Electrical Schematic

Critical Systems:

Top level pseudocode:

Controller pseudocode

Controller pseudocode

Bill of Material (BOM)

Example section from Bill of Materials

Example section from Bill of Materials

Due to its size, only a snapshot of the BOM is shown above. The full document can be accessed here.

Risk Assessment

Risk Assessment Chart - Updated for Phase 3

Risk Assessment Chart - Updated for Phase 3

Risks were re-assessed following Preliminary Detailed Design review. Risks were updated to remove unnecessary considerations and more closely follow the tasks actually being carried out by the team members.
Risk Management list, updated from previous design review

Risk Management list, updated from previous design review

Risk Explanation

Risk Explanation

Link to the live risk assessment document here. For a link to the previous (now outdated) risk management document presented at previous design reviews, click here.

Problem Solving Process

1st Draft Problem Solving Process

1st Draft Problem Solving Process

Link to the live document here.

Team Shared End State Vision

Best Case Scenario:

Team will demonstrate our fully working prototype with results fully backed by an in depth error analysis. The prototype will be able to measure CTE of 1 high expansion and 1 low expansion material. A BOM will be handed off telling Harris what components are needed to reach the specified accuracy they desire. Instructions for using the system, how to build and test will also be provided. Overall, this best case scenario will leave Harris pleased with the end result with all our goals and requirements met. Harris will be able to buy the high end components, file the patent and begin utilizing their new CTE tester.

Moderate Case Scenario:

Working prototype is demonstrated but error analysis has not quantified every source of error. This means that our prototype demonstrates the MagLev feasibility and is able to obtain measurements for CTE however, we can only speculate the complete error within our measurement. A plan of action for how error analysis can be carried out can still be provided. Supporting documentation such as usage instructions may or may not be provided. Suggestions for upgraded components would still be provided to Harris, but the final error analysis may not be useful to Harris due to the high degree of uncertainty. In this case, Harris would most likely be displeased and lack of effort from our team would be apparent. Since this moderate case leaves Harris with an incomplete project, there is potential for another MSD team to finish this project as a continuation.

Worse Case Scenario:

No working prototype is produced, no error analysis or it is not near completion and we do not list suggestions for upgraded components. Overall, Harris is disappointed, we make our guide look bad, and we look bad as engineers. Our reputation as well as the reputation of RIT is negatively impacted. If project is continued by another MSD team, they may need to start over completely due to a lack of useful documentation from our part.

Review of MSD II schedule

Tasks and Plans for Phase 1 of MSDII

Tasks and Plans for Phase 1 of MSDII


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