P18222: RIT Baja Two-Node DAQ
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Detailed Design

Table of Contents

Team Vision for Detailed Design Phase

Team's Vision

Team's Accomplishments

Progress Report

Since our preliminary detailed design review, we have done more lab testing and analysis. Our primary focus has been on the strain gauge amplifier circuit. Recently, we put together an amplifier circuit using analog discovery OP-27 and used only fixed resistors in the strain gauge bridge. We were able to confirm the measured gain was correct through calculations. In addition to the strain gauge circuit, we received the SD breakout board and successfully were able to read and write to an SD card.

Over Thanksgiving break, we plan to do additional research on amplification circuits for quarter bridge strain gauges and do PSpice simulations. Edge will be updated with any changes to the customer and engineering requirements, function decomposition, and the team’s vision for this phase. Additional research will be done for the enclosure to come up with a solution on what will be able to house all of our components and still meet the size requirements. Lastly, we plan to finalize the schematic for Node 1 so we can proceed with the PCB design.

When we come back from break, we plan to go to the lab to test our amplifier circuit with actual strain gauges to confirm it will work. Once we determine the amplifier circuit will work, the schematic for Node 2 will be finalized and the PCB design can be finished. The bill of material will be updated with all the components needed to make the final prototype, the risk assessment will be updated with any new risks, the test plans will be updated based off of any new engineering requirements and tests that have been executed, and a schedule for MSD II will be made.

Prototyping, Engineering Analysis, Simulation

Quarter Bridge Strain Gauge Amplifier

Beginning stage using a basic Op-amp:

Lab Testing

Lab Testing

Lab Testing Results

Lab Testing Results

After further analysis and research, an instrumentation amplifier was analyzed and tested:

Strain Gauge Amplifier Schematic

Strain Gauge Amplifier Schematic

Strain Gauge Amplifier Input & Output

Strain Gauge Amplifier Input & Output

Test Setup

Test Setup

Calculation vs. Experimental Results with varying Shunt & Fixed Resistor

Calculation vs. Experimental Results with varying Shunt & Fixed Resistor

Experimental Graph with varying Shunt & Fixed Resistor

Experimental Graph with varying Shunt & Fixed Resistor

Testing with an Actual Strain Gauge

Testing with an Actual Strain Gauge

When testing the strain gauge in the lab, the resistance was measured to be 350.6ohms. After further research, National Instruments said to perform three wire measurements to eliminate the resistance in the wires. New simulations were performed.

National Instruments Setup

National Instruments Setup

Updated Schematic with Three Wire Configuration

Updated Schematic with Three Wire Configuration

Simulations with Three Wire Configuration

Simulations with Three Wire Configuration

To fully utilize the ADC in the MBed, the output of the instrumentation amplifier is fed into a non-inverting op-amp.

Simulations with Three Wire Configuration Fed into Non-Inverting Op-Amp

Simulations with Three Wire Configuration Fed into Non-Inverting Op-Amp

Voltage Regulator

Battery to +5V Boost

Battery to +5V Boost

Positive to Negative Inverter Schematic

Positive to Negative Inverter Schematic

Positive to Negative Inverter Simulations

Positive to Negative Inverter Simulations

SD Card Read/Write

SD Card Setup

SD Card Setup

SD Card Schematic

SD Card Schematic

Raw Data

Raw Data

Drawings, Schematics, Flow Charts, Simulations

Systems Architecture

System Architecture

System Architecture

Software Flowchart

Overall Software Flowchart

Overall Software Flowchart

Main Node Software Flowchart

Main Node Software Flowchart

Node 1 Software Flowchart

Node 1 Software Flowchart

 Node 2 Software Flowchart

Node 2 Software Flowchart

 CAN Software Flowchart

CAN Software Flowchart

The live Full System Flowchart document can be found here.

Updated Customer Requirements

Updated Customer Requirements

Updated Customer Requirements

The live Customer Requirements document can be found here.

Updated Engineering Requirements

Updated Engineering Requirements

Updated Engineering Requirements

The live Engineering Requirements document can be found here.

Updated Functional Decomposition

Functional Decomposition

Functional Decomposition

Main Node Schematic

Final Main Node Schematic

Final Main Node Schematic

Node 1 Schematic

Final Node 1 Schematic

Final Node 1 Schematic

Node 2 Schematic

Final Node 2 Schematic

Final Node 2 Schematic

Bill of Material (BOM)

Final BOM

Final BOM

The live Bill of Materials can be found here.

Test Plans

The live Test Plans document can be found here.

ER1 Test Plan

The goal of this test is to confirm data can be collected from the hall effect sensors at the required sampling rate of 100Hz.

ER2 Test Plan

The goal of this test is to confirm data can be collected from the strain gauges at the required sampling rate of 500Hz.

ER3 Test Plan

The goal of this test is to confirm temperature readings from a thermocouple can be obtained at the desired rate of 1 Hz.

ER5 Test Plan

The goal of this test is to confirm data can be saved onto an SD Card

ER6 Test Plan

The goal of this test is to confirm data can be Transferred via CAN (Controller Area Network)

ER8 Test Plan

The goal of this test is to make sure IP standards will be met for the connectors. A male to female pair will be mated, submerged in a container of water for five minutes. Once the time is up, the connectors will be removed and validated no water is inside.

ER9 Test Plan

The goal of this test is to make sure IP standards will be met for the enclosure. The enclosure will be submerged in water for thirty minutes. Once the time is up, the enclosure will be removed from the water and validate no water got into the enclosure.

ER16 Test Plan

The goal of this test is to ensure data can be pulled from the SD Card using the MBed via a cable to confirm data can be removed from the node without opening the enclosure

Risk Assessment

The latest risk's for the project.
Risk Assessment

Risk Assessment

The live Risk Assessment document can be found here.

Plans for MSD II

MSD II Schedule

MSD II Schedule

The live schedule can be found here.

Individual Plans

Member Plan
Odysseus Adamides MSDII
Amanda Vallat MSDII
Ross Erwin MSDII
Joseph Green MSDII

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