P18011: Wheelchair Accessible Restroom 2
/public/

Systems Design

Table of Contents

Team Vision for System-Level Design Phase

Our Plan For This Phase

During this phase, we hoped to gain an even better understanding of the problem through benchmarking and further discussion with our customer. We hoped to generate concept ideas and use feasibility testing to begin narrowing down our possibilities. We also plan to make updates to our documentation from the Problem Definition phase.

What We Actually Accomplished

We developed multiple concepts for each of our required functions, as well as for our design as a whole. We began basic feasibility studies for specific aspects of our design, such as the seat, lift, and grab bars. Lastly, we continued our benchmarking and updated customer/engineering requirements.

Functional Decomposition

Below is out Functional Decomposition chart. We strove to keep the functions general so that they didn't limit our concept ideas.

Functional Decomposition

Benchmarking

In order to better understand how our design needs to fit within ADA specifications, we did further research on ADA requirements.

ADA Requirements

ADA Requirements

To ensure that our design is able to be used by our target customer, we did some further on reach parameters by those in wheelchairs.

Reach Measurements

Reach Measurements

We also explored several different existing US patents to see if we could find devices that use functions that we desire to recreate in our preliminary designs.

Patent 5027446 is very similar to what we would like to replicate in terms of vertical lift function. It does lack side support and transfer aids.

Patent 5027446 is very similar to what we would like to replicate in terms of vertical lift function. It does lack side support and transfer aids.

Patent 5027446 is a stand-aid seat. While the lift functions differently from what we would like to see in our end-product, we like the way the seat is integrated into the frame and the side supports that the frame provides (though not adjustable).

Patent 5027446 is a stand-aid seat. While the lift functions differently from what we would like to see in our end-product, we like the way the seat is integrated into the frame and the side supports that the frame provides (though not adjustable).

Concept Development

We brainstormed concept ideas for each function. We listed these ideas on a whiteboard and images of our work are displayed below.

Concepts for

Concepts for "Aid Transfer" function

Concepts for

Concepts for "Support User" function

Concepts for

Concepts for "Raise Seat" function

Feasibility: Prototyping, Analysis, Simulation

  1. Will our design compatible with multiple toilets?
In order to answer this question, we benchmarked numerous toilet designs in order to compile range values for public toilets. Below is a table with our findings:
Toilet Sizes

Toilet Sizes

Feasibility-cantilever.xslx
  1. Preliminary Grab Bar Feasibility

For the grab bar feasibility, we first conducted a simple cantilever beam analysis in order to obtain the allowable stress on the bar from our max load. The analysis is documented below:

Hand Calculations for Beam Analysis

Hand Calculations for Beam Analysis

Here is the excel representation of Beam Analysis

Morphological Chart and Concept Selection

Morphological Chart

Morphological Chart

Link to full Morphological Chart here: Morphological Chart

Concept Selection

Sample Section of Pugh Chart

Sample Section of Pugh Chart

The entire Pugh chart can be viewed here.

Systems Architecture

SystemArchitecture

SystemArchitecture

Designs and Flowcharts

Flow of User Inputs and loads

Flow of User Inputs and loads

Risk Assessment

Updated Risk Assessment

Updated Risk Assessment

Design Review Materials

https://www.engineersedge.com/beam_bending/beam_bending1.htm

Plans for next phase

  1. Material testing and selection
  2. Research what materials will meet our design needs
  3. Understand machining capabilities offered at RIT
  4. Understand purchasing
  5. Order test materials

Systems Design Review


Home | Planning & Execution | Imagine RIT

Problem Definition | Systems Design | Preliminary Detailed Design | Detailed Design

Build & Test Prep | Subsystem Build & Test | Integrated System Build & Test | Customer Handoff & Final Project Documentation