P18025: ZoomTots RIT
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Preliminary Detailed Design

Table of Contents

Team Vision for Preliminary Detailed Design Phase

The plan for this phase of the design process was to choose our most critical and potentially difficult systems and focus primarily on making significant progress on them. Through research and expert input, we wanted to be sure that the most difficult components of our design were solidified by the preliminary detailed design review.

Tasks Completed During this Phase

Member Tasks For This Phase
Group Tasks
  • Created a large list of tasks for each critical subsystem
  • Decided on the primary focus for this phase which includes
    • Designing the mounting system
    • Finding an appropriate car seat for A
    • Figuring out how to implement power steering in the vehicle
    • Coming to a concrete conclusion about the child control method
  • Focused on updating the edge page regularly
Kathryn Cyr
  • Kept a close correspondence with the customer
  • Met with Leah (the customer) and summarized the meeting
  • Worked with Mia and Brady to design the mounting system
  • Sourced materials for the mounting system
  • Created a test plan for the chosen child controls
  • Contacted Kelly Gilroy to test child controls with some of her patients
Austin
  • Researched potential motors for power steering
  • Created wiring diagram of existing car
  • Created preliminary microcontroller architecture
  • Worked with Allison and Alaiya to create steering designs
  • Laid out future plans for the microcontroller subsystem
Brady Sweeney
  • Researched and compile mounting standards for car seats
  • Created a new BOM, combo of budget, BOM, and spending tracker
  • Found an ergonomics expert, met with him, and summarized the meeting
  • Worked with Mia and Katherine to design the mounting system
Alaiya
  • Found a method for powering the microcontroller
  • Looked into potential subject matter experts for motors
  • Chose AutoCAD as our preferred schematic software
  • Worked with Austin and Allison to create steering designs
  • Updated the risk assessment
  • began to make/find prototypes for testing child controls
Mia
  • Created a document to present our current progress to Leah
  • Researched and summarized safety standards
  • Researched and summarized car seats
  • Worked with Brady and Kathryn to design the mounting system
  • Began creating a CAD model of the chosen mounting system
Allison
  • Remade Gantt chart using new template
  • Worked with Austin and Alaiya to create steering designs
  • Found a gear expert, met with him, and summarized the meeting
  • Reformatted the preliminary detailed design edge page for clarity
  • Created meeting agendas and assigned tasks to other team members

New Gantt Chart

We switched to a new Gantt chart template made by Miguel Gutierrez (Team P18365). To see the working version of the new Gantt chart, click here.
Snip of New Gantt Chart

Snip of New Gantt Chart

Customer Meeting - Leah Talbot (3/26/2018)

New car seat donated by Wayne County Public Health

New car seat donated by Wayne County Public Health

Child Controls

Control Discussion - Leah Talbot (3/26/2018)

Ergonomics Expert Meeting - Dr. Matthew Marshall (3/29/2018)

Test Plan

There are multiple different child control options that we would like to test:
Child Control Options

Child Control Options

Turn and Learn Driver

Turn and Learn Driver

Future Plans

test joystick

test joystick

  1. Determine the control types to use after Kelly/Sara meeting
  2. Categorize control groups based on age so A can increase his level of control as he ages
  3. Make prototypes of the controls and re-visit the kids with CP to test
  4. Determine control mounting system (PS4 controller, design our own, etc)
  5. Source materials for control mounting system and controls themselves

Microcontroller Stuff

Wiring Diagram for Existing Car

Current Car Wiring

Current Car Wiring

Microcontroller Update

Microcontroller Interface Connections

Microcontroller Interface Connections

How to Power Microcontroller

Power GEREE DC DC Converter Step Down 12V 24V to 5V Micro USB Cable Low Voltage Protection

Power GEREE DC DC Converter Step Down 12V 24V to 5V Micro USB Cable Low Voltage Protection

Future Plans

Child Restraint System and Mounting System

Mounting Standards

Latch Standards

Latch Standards

Mounting Designs

Sketch of LATCH mounting design.

Sketch of LATCH mounting design.

Sketch of possible cutout attachment design.

Sketch of possible cutout attachment design.

Sketch of the 80/20 back support design.

Sketch of the 80/20 back support design.

Final Mounting Design

Sketch of car seat and mounting design.

Sketch of car seat and mounting design.

Mounting System Materials

Car Seat Overview

Features considered for choosing a car seat:
Car Seat Options
Buying options for car seats.

Buying options for car seats.

Evenflo SureRide Titan 65 car seat (donated).

Evenflo SureRide Titan 65 car seat (donated).

Future Plans

  1. Finish CAD model of the mounting system design
  2. Decide whether or not a prototype of the mounting system will be necessary

Steering System

Current Steering Setup

Steering rack and frame

Steering rack and frame

Steering rack and axle

Steering rack and axle

Initial Steering Designs

Power Steering Design 1: 2 Gear Method

Power Steering Design 1: 2 Gear Method

Power Steering Design 2: Original Column with Servo Attached

Power Steering Design 2: Original Column with Servo Attached

Power Steering Design 3: Shortened Steering Column with Sero Attached

Power Steering Design 3: Shortened Steering Column with Sero Attached

Power Steering Design 4: Bevel Gear Method

Power Steering Design 4: Bevel Gear Method

Meeting with Gear Expert - Dr. Fuentes Aznar (3/28/2018)

Iteration 2 of Steering Design

Current Favorite Design

Current Favorite Design

Meeting with Gear Expert - Dr. Fuentes Aznar (4/4/2018)

Future Plans

  1. Source materials for the pin and slot steering design
  2. Choose and source a motor to use in the pin and slot design
  3. Design a mounting method for motor to chassis
  4. Figure out how the motor will be powered

Bill of Materials (BOM)

Current Favorite Design

Current Favorite Design

To see the working version of the new BOM, click here.

Risk Assessment

Risk Assessment

Risk Assessment

Topic Summary Standards
Stability

Many tests, including seeing if vehicle tips over on a 15° incline plane when it is overloaded, driving toy into a step with a height of 50 mm and tipping over vehicle.

(ISO 8124-1:2014 Sections 4.15, 5.12.3, 5.12.4, 5.24.3, 5.24.4) (ASTM F963-17 Sections 8.7, 8.15, 8.21, 8.28)

Openings/Entrapments/Sharp Edges

Holes need to have a diameter smaller than 5mm or bigger than 13mm.

Sharp edges are tested with a piece of adhesive tape attached to a mandrel and rotated along sharp edge. Less than 50% of the tape should be cut after the test.

(ASTM F963-17 Section 4.18.1) (ISO 8124-1:2014 Sections 4.13.1, 4.13.2, 4.18.1, 4.39.3)

(ISO 8124-1:2014 Sections 4.6.3, 5.8)

Tension and Torque Tests

Apply a 0.45 Nm torque evenly for 5 second period and maintain for 10 seconds.

Apply a 70 N force parallel and perpendicular to the major axis of the test component evenly over a period of 5 seconds and maintain for 10 seconds.

(ISO 8124-1:2014 Section 5.24.5) (ASTM F963-17 Sections 8.8, 8.9)

(ISO 8124-1:2014 Section 5.24.6)

Battery

General safety requirements, including not exceeding maximum temperature ratings, no short-circuit conditions when tested, and no risk of fire.

Shall carry safety labeling consisting of the word “WARNING”, “RISK OF FIRE” and text that indications how to reduce the risk of injury.

(ASTM F963-17 Section 4.25, 8.18, 8.19)

(ASTM F963-17 Section 5.15)

Braking

If car is considered free wheeling (rolls down an 10° incline with a 50 kg mass), there must be a braking device that prevents it from moving more than 5 cm when tested on a 10° incline.

If car is more than 30 kg, a parking brake is necessary.

The switch (which turns on the vehicle) shall cut off power automatically when released.

(ISO 8124-1:2014 Sections 4.21, 5.16.1, 5.16.2)

(ISO 8124-1:2014 Section 4.21)

(ISO 8124-1:2014 Section 4.21)

Speed

Electrically driven ride-on toys shall have a maximum speed of 8 km/h.

(ISO 8124-1:2014 Sections 4.23, 5.17)

Design Review Materials

Include links to:

Plans for next phase (Very high level)

Electrical Team

Mechanical Team

Other


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