P18071: Wireless Concussion Detection
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Preliminary Detailed Design

Table of Contents

Team Vision for Preliminary Detailed Design Phase

Summary: With the the systems design of the project being completed, more detailed designs and flowcharts were to be laid out. The main focus for this section on the mechanical side was to discover a viable testing fixture for the helmet and sensor. This way we could begin construction of the test fixture and begin preliminary tests in the next phase. The software focus on the other hand was to have all of the proof of concept code generation to be finished. This way the next phase could focus connecting these software components together and begin testing their connections.

Goals

Software

Electrical

Mechanical

Completed

Software

Electrical

Mechanical

Prototyping, Engineering Analysis, Simulation

Work that we have completed so far

Software:

Electrical:

Mechanical:

Protective Case CAD Design

Protective Case CAD Design

Feasibility: Prototyping, Analysis, Simulation

What we are planning on completing in future phases

Software:

Electrical:

Mechanical:

 Testing Options

Testing Options

Option Description Pros Cons
Option1 Helmet is on top. Bottom of rig hits ground surface causing a shock. High G levels Nowhere for guide rails or MEP.
Option2 Helmet is dropped from rig and hits ground surface causing a shock. Can use guide rails and MEP Some control over G level but not much
Option3 Helmet is falls with rig, helmet hits ground causing shock Control over G level and guide rails could be used Not sure if there is enough room for MEP

Drawings, Schematics, Flow Charts, Simulations

Software

Raspberry Pi UDP Flow Chart

Raspberry Pi UDP Flow Chart

Raspberry Pi Bluetooth Flow Chart

Raspberry Pi Bluetooth Flow Chart

Android Bluetooth Flow Chart

Android Bluetooth Flow Chart

Electrical

Power Management Electrical Design

Power Management Electrical Design

BQ24023

BQ7421

TSP7401

Additional Requirements

Mechanical

ASTM positioning planes on head

ASTM positioning planes on head

Testing Schematic

Testing Schematic

Bill of Material (BOM)

Current Bill of Materials

Current Bill of Materials

A link to the Bill of Materials could be found here

Test Plans

To meet ASTM standards for hockey helmet impacts, the following tests must be undergone:

Updated Testing Flowchart

Updated Testing Flowchart

Shock Test

For one helmet conditioned at ambient conditions:

12.2.1 Front—The point on the midsagittal plane which is 50 mm (1.969 in.) above the anterior intersection with the reference plane.

12.2.2 Side—The point 25 mm (0.984 in.) above the reference plane and 90° from the anterior intersection of the midsagittal plane and the reference plane (intersection of the reference and coronal planes).

12.2.3 Rear—The point at the posterior intersection of the midsagittal and reference planes.

12.2.4 Crown—The point where the central vertical axis meets the top of the headform.

12.2.5 Rear Boss—A point in a plane 135° (2.36 rad) in a clockwise direction from the anterior intersection of the median and reference planes and on the reference plane.

12.2.6 Front Boss—A point in a plane 45° (0.78 rad) from the median plane as measured in a clockwise direction and 25.4 mm (1 in.) above the reference plane.

12.2.7 Test Line—Draw test line A-B-C-D-E-F on the headform as indicated in Fig. 8.

For a second helmet conditioned at ambient conditions:

12.2.8 Non-Prescribed Impact Locations—Non-prescribed impacts shall be located on the headform. The first point of contact with the anvil for any non-prescribed impact location shall be on or above the test line and at least one-fifth of the circumference of the headform from any prior impact location on that helmet. The headform is positioned so that the impact location is the first point of contact with the anvil. The helmet is then placed on the headform as specified by the manufacturer’s head positioning index (HPI). The location of these two non-prescribed impact locations may be identified by the arc distance along the reference plane from the anterior intersection of the midsagittal plane with the reference plane, clockwise or counterclockwise, and the perpendicular arc distance from that point on the reference plane to the non-prescribed impact location.

Temperature Testing

11.1.2 Low Temperature—The low temperature is at a temperature of -23 to -27°C. Helmets shall be conditioned for a period of not less than 4 h nor more than 24 h.

11.1.3 High Temperature—The high temperature is at a temperature of 28 to 32°C. Helmets shall be conditioned for a period of not less than 4 h nor more than 24 h.

11.1.4 Testing for Conditioned Specimens—Complete all testing on helmets within 5 min after removal from the conditioning environment. Helmets may be returned to the conditioning environment in order to meet this requirement. Prior to the resumption of testing, specimens must remain in the conditioning environment for a minimum of 15 min for each 5-min period they are out of the conditioning environment. The hot and cold conditioned helmets will be impacted at the two positions found during Test 1 that displayed the highest impact data.

Raspberry Pi Testing

Run a synthetic test on the Raspberry Pi to utilize CPU resources as the same time the bluetooth connection program and UDP packet reading program is running. This is to test how the applications will handle running when it is under extreme load.

The next test on the raspberry pi requires it to be connected to a computer over ethernet, the computer will then send UDP packets to the Raspberry pi acting as the collector. The UDP packets that are sent will be structured the same as if they were coming from the collector. Since the computer would be able to send packets faster than the Raspberry Pi could handle them, it would show what is the max speed it can process data as well as where and what happens when the Raspberry Pi misses packets

Database Testing

The database will be populated with roughly 200,000 entries to simulate a lot of use. The application will then be started with actual data from the android application. The test is to see how quickly the database is able to process the data. If there is a significant time increase in the delay for data retrieval, then the DB schema needs to be changed or there needs to be more resources allocated to the DB.

Android Testing

The android application will be the main UI the end user will be using, therefore needs to be simple enough for any user, while also providing enough information they require. Testing will be done to verify the proper connections are in place and can communicate with both the Raspberry Pi and the amazon database. The application should be able to obtain info from the raspberry pi, display the info to the user, as well as sending the info to the database. Testing then needs to ensure secure and lasting connections, as well as being able to view all the necessary information without slowing down the application.

PCB Design Testing

Obtain a protoboard and all components necessary to build a prototype of the power management PCB, along with the batteries used to power the design. Then test for the current draw, voltage output, noise, and IC communication with the processor. Any unsatisfying results will result in a re-evaluation of the parts chosen to improve the design.

Risk Assessment

Risk Assessment

Risk Assessment

For a full list of Risks, click here.

Design Review Materials

Link to the Pre-read is located here.

Plans for next phase

The list of individual three-week plans can be found here

Mechanical

Mechanical

Electrical and Software

Electrical and Software

Project Management and Prototyping

Project Management and Prototyping


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