P18422: Black Soldier Fly Composting Habitat Improvement
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Detailed Design

Table of Contents

Team Vision for Detailed Design Phase

Design Review Notes

From Preliminary Detailed Design Phase Suggestions, the team:

During the Detailed Design Phase, the group plans to:

Our overall work breakdown plan for the Detailed Design Phase:

Progress Report

  1. Update on Detailed design page
    1. Post Percent Completion Table w/notes on what we’ve done
    2. What does the team plan to accomplish by the Detailed Design Review?
      1. Finish prototyping selected system in order to analyze feasibility and challenges of the proposed design. This includes:
        1. Prototyping migration ramps.
          1. See the Migration Ramp Experiment Document.
        2. Prototyping electrical systems.
        3. Summary of Mesh Research
      2. Finish validation through calculations in an effort to ensure composter and shed systems are feasible to meet engineering requirements:
        1. Verification of Heat Transfer Equations to Determine Heat Required
      3. Create a final 3D rendering of the proposed systems as well as a simulation of how the subsystems function together. Designs will be reviewed with subject matter experts in order to ensure manufacturability.
      4. Confirm with Bill Labine that DC components should be utilized in order to maximize power if power cannot be obtained from RIT.
      5. Finalize plans for where and what electrical components will go in the shed so that they can be wired up and the shed can be insulated.
      6. Refine test plan and associated data sheets into finalized format from initial format.
      7. Continue updating the risk assessment matrix to ensure that the proper attention and mitigation strategies are in place (so as to minimize the impact of potential risks).
      8. Finalize a Bill of Materials to ensure that the project is on budget and all required materials will be purchased.
      9. Write and submit IEEE grant application (see grant proposal timeline in project plan for more information).
    3. What tasks have been accomplished so far and what tasks remain, and who is the owner of each?
      1. See the Progress Report Table for a detailed list of tasks accomplished and remaining.
    4. What decisions have been made so far?
      1. DC vs. AC for electrical system
        1. See the DC vs AC Pricing Document.
      2. Standards used for the IEEE grant
      3. Initial purchase decisions for microcontroller
      4. Equipment selection and prioritization
    5. What questions does the team have for the customer and/or guide in order to continue moving forward?
      1. Are the solar panels and batteries 12 volts?
        1. Check with Bill to see if we can get 12 volt inverter to work with 24 volt panels
      2. What is the priority of components that we are purchasing?
      3. Assistance completing the IEEE grant?
        1. Address - see handout
        2. April 30th Due Date
      4. Can we post IEEE grant proposal to EDGE site?
        1. Sarah does not see why we could not/ put in private folder on EDGE
      5. Availability for Gate Review
        1. 10:00 am on Wednesday the December 13th
  2. Post any completed work to Edge on DDR page to get ahead for review
  3. Check Planning and Execution page to ensure updates through Phase III
  4. Give guide plus/deltas at this link: https://goo.gl/forms/yXVA2Y0FcBHiUJtt1

Feasibility

Mesh/Frass Research Summary

Source: The previous MSD team did extensive research into using either a coarse mesh or a fine mesh to drain the excess liquids in the system.

Experiment: In this experiment they had two samples of each type of filter. A1 and B2 are using the coarse mesh and A2 and B1 use the fine mesh. They placed food waste and larvae into each jar and over the course of several weeks reviewed the drainage.

Results:

Conclusion: Ultimately the coarser mesh was chosen because of these above results and its ability to better drain liquid out of the system without disturbance to the larvae.

Link to our Mesh Research Summary.

Migration Ramp Experiments

Further migration ramp testing was done to determine the feasibility of smooth vs. rough ramps along with “swim lanes” for the angled sides of the reactor. After 6 trials, it was seen that there was not a distinguishable difference between smooth or rough ramps which led to the conclusion that in order to save time for the machinist smooth sides would be used in the reactor.

Further explanation of the experiments can be seen in the Migration Ramp Experiments - Swim Lanes Document.

Heat Calculations

Heating requirements were calculated for both the shed and the composter.

Assumptions:

Link to the Composter Heat Calculations Document.

Conclusions:

Electrical Systems

Sensors

After benchmarking some sensors last phase, the Sensor Justification Document shows our reasoning behind the final decision.

Test plans for the code collected is planned for the next phase is located in the Control System Testing Document. There are two tests planned:

Both tests will provide verification that the code used works properly and can operate in parts in the event that a problem cannot be debugged.

AC/DC Price Comparison

DC vs AC Pricing Table

DC vs AC Pricing Table

The table above contains the information regarding the comparison between DC and AC component. This research was done when the group was deciding on going with DC or AC components. From the data it becomes evident that AC powered equipment are cheaper than DC components, there are multiple reasons that attribute to this but the most common is the fact that DC components are not widely produced and are specialty equipment for vehicles.

Link to DC vs AC Pricing Document.

Charge Controller Research

The charge controller is used for monitoring and controlling the amount of charge that get applied to the batteries from the solar panels. Various charge controllers with similar specs (Input: 12/24V DC, 40A) were compared. The main criteria for comparison was the price for each unit and one that accommodated the budget the best was selected.

Link to Charge Controllers Documentation.

Equipment Selection

Wattage Calculations:
Equipment Selection

Equipment Selection

For these calculations we looked at each of the different choices for sub-components to include in this system and estimated how many hours per day we ideally would like to run it. We then calculated how many Wh/d each component would take and how many we would need for the whole system. For the entire system, we would require 5.87kwh/day and to heat just the composter we would require 2.27 kwh/day. The downside with this later system is that we would not be able to run breeding in the shed.

Battery Calculations:

Comparison was performed between the 12V and 24V batteries. These batteries were compared by their Amp Hr rating with this information then being used for calculating the number of required. There was a significant amount of information available for the 12V batteries while the 24V model lacking in this department. With the 12V batteries a step down transformer would be required as the power provided from the solar panels is 24V, but this requirement would be filled as the current inverter also requires a 12V input feed.

Link to the Equipment Selection and Prioritization Document.

Power Options

Solar Vs. FMS: Link to Solar vs. FMS Document.

Power Requirement: 5.87kWh/day of energy needed to power shed (for explanation see spreadsheet in above section)

Power off RIT Grid:

Pros:
1. Could maintain ideal conditions year round.
2. Do not need to convert power because input is already AC.
Cons:
1. Very expensive, would be a long term solution and does not help now.
2. Does not help goal to become carbon neutral on campus.

Power from Solar Panels:

Pros:
1. Clean energy source.
2. Already have 4 panels available to us.
Cons:
1. Very expensive to meet energy demands, would need to be long term solution.
2. Lack of space to install necessary number of solar panels.
3. Would need to convert from DC to AC power to use in shed.

Heating and Power Benchmarking:

Heating Power Benchmarking

Heating Power Benchmarking

The results of the power calculation told us that we only need 2.25 KWh of electricity per day to run this system. We plan to use the solar panels we have in parallel with batteries charged with a generator. This is our chosen method because buying the additional 10 solar panels would exceed our budget and batteries are less expensive than solar panels. The batteries could be charged with a generator or off RIT power. This would only be necessary in the winter time, in the summer we should have more than enough energy with the solar panels we have. The only downside of this method is that until a long term solution can be reached, we cannot breed inside the shed.

We have concerns with this design moving forward such as maintaining the aerobic conditions inside the composter as well as insulating the migration ramp exit while still giving them a light to migrate towards. These concerns will be considered moving forward as it does not change the overall design of the composter and more effects the electrical systems inside the shed. For more information see: Heating Power Benchmarking Document.

Ergonomics

An initial pass was made at the standard operating process that a single operator would complete in their interfacing with the system contained in the shed. Additionally, a basic evaluation into the physical effort required by operational elements relative to the composting system was completed. The following table illustrates the tasks or activities that an operator would need to complete, providing insight into the areas that have been identified as opportunities for ergonomics and usability to be considered:
Process Table

Process Table

This process can also be modeled in the following manner:

Process Flow

Process Flow

Using these work elements along with the additional considerations made (see documentation for details), the Ergonomic Assessment was completed. Findings from this analysis include that:

Drawings

Composter

The mechanical drawings have been updated from last phase from feedback gained from subject matter experts. Major changes include the demotion of the lid assembly to the reactor body subassembly, the addition of “swimlanes” to aid in larva migration and the addition of a support structure. Currently, the support structure is expected to be manufactured from wood available at no cost. In addition to the updates, a stress analysis was performed on the composter. We found that under a normal load, the sides of the composter began to bow outwards. In order to mitigate this, support has been added to that wall using angle iron.

Link to Drawing Packet Document.

Electrical

The Electrical Drawings show the one line schematic for the electrical system in the shed. Two versions were created. Version 1 includes the inverter provided and is set up accordingly with the solar panels providing 24V DC which goes through a Charge controller, then passes through a step-down transformer which bring down the voltage from 24V DC to 12V DC. The stepped down voltage is then fed to 12V batteries which supply 12V DC to the inverter which converts 12V DC to 117v AC which is supplied to the distribution box. Version 2 has a similar set up as Version with the differences coming from the fact that the new inverter will not require step-down transformer therefore the 24V batteries are used.
New Inverter

New Inverter

Old Inverter

Old Inverter

Raspberry Pi

Raspberry Pi

Software

To begin creating the code that will automate the climate control, a program flowchart was created to visualize how the code would operate. The code used in the project will be a combination of code from similar projects found online and code created by the team to connect the pieces of code.

As seen in the Code Flowchart, the program will begin by taking readings from all the sensors. It will then compare these values to a preset value and will then send a signal to the relay which will either turn on or off the related equipment. As of now, the data will be recorded every 2 hours, however this can be changed after further testing in the next phase. This code will be set to cycle every minute to ensure the shed and larvae are kept at optimal conditions.

All code samples and the coding plan are both found in the Pseudocode and Testing Documentation Document.

Bill of Materials (BOM)

The Bill of Materials was updated to reflect the prices of each individual item along with where the funding for certain items was coming from.

Pending the receipt of the IEEE grant along with the funds donated from Shwe Sin graduate studies the available budget would be $1,350.

Test Plans

Link to the Test Plan Document.

Updates:

Plans for Next Phase:

Flow Summary

Link to our Engineering Requirements Flow Summary.

Risk Assessment

The team reviewed and updated the cumulative Risk Assessment that was first created in the Problem Definition phase of the project (and has been updated during every project phase thus far). It is important to note that Risk REN4 was successfully mitigated and, thus, removed from the below table. Please review the Planning and Execution page of the project site in order to gain additional information on this.

Risk Matrix

Risk Matrix

As this phase progressed, it also became aware to the group that risks experienced changes to their impact values. Specifically, risks REN4, RRS6, and RTC6 decreased in impact values. This suggests that more attention and effort was placed upon these items and relatively less attention on these will be required moving forward.

Risk Deltas

Risk Deltas

Risk Mitigation

Risk Mitigation

Design Review Materials

Detailed Design Review Agenda

Equipment Selection and Prioritization

Engineering Requirements

Plans for next phase

IEEE Grant Submission:

As a push to increase the available budget of the project the team is applying for the IEEE Student Grant which could increase the budget by $500.

The standards being proposed for the project are the following:

A full list of standards that were researched can be seen in the Standards Repository Research for IEEE Grant document

During the Build and Test Prep Phase, the group plans to:

Our overall work breakdown plan for the Build and Test Prep Phase:


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