P18392: Remote Control Bicycle Braking System
/public/

Systems Design

Table of Contents

Team Vision for System-Level Design Phase (Nick)

The goal for this phase was to come together as a team and make high level design decisions in order to give an overall "shape" to our final product. This phase is an important stepping stone between generating the customer and engineering requirements and figuring out the the specific real-world components that will comprehensively solve the problems defined in the problem definition phase.

Entering this phase our goals were originally to:

As we moved forward, the following was accomplished:

Revised Requirements (Justin)

Customer Requirements

(1-High, 3-Moderate, 5-Low)

(1-High, 3-Moderate, 5-Low)

Engineering Requirements (Metrics & Specifications)

(1-High, 5-Low)

(1-High, 5-Low)

Updated Risk Assessment (Eli)

Updated Risk Management

Updated Risk Management

FMEA (Nick)

FMEA

FMEA

Functional Decomposition

Functional Decomposition of SafeStop

Functional Decomposition of SafeStop

Benchmarking (Gabe & Eli)

Microcontroller

Microcontroller Benchmark

Microcontroller Benchmark

Wireless

Wireless Benchmark

Wireless Benchmark

Battery

Battery Benchmark

Battery Benchmark

Actuator

Actuator Benchmark

Actuator Benchmark

Concept Development and Morphological Chart

Brake System Morph Chart

Brake System Morph Chart

Mechanical Interface Morph Chart

Mechanical Interface Morph Chart

Remote Morph Chart

Remote Morph Chart

Concept Selection and Pugh Charts

The following are the Pugh matrices created by the team for different aspects of the overall system.
Remote Pugh chart

Remote Pugh chart

Brake System Pugh chart

Brake System Pugh chart

Mechanical Disconnect pugh

Mechanical Disconnect pugh

Remote Battery pugh

Remote Battery pugh

General Design (Eli)

Alert Cluster Design

Alert Cluster Design

Feasibility: Prototyping, Analysis, Simulation

Financial Feasibility (Steven)

Preliminary Budget

Actuator Feasibility (Steven)

Forces Acting Upon Brake Lever

Forces Acting Upon Brake Lever Feasibility Calculations

Using the derived force, a potential actuator was found from Firgelli Automations.

Figurelli Actuator Range

Firgelli FA-150-S-12XX Firgelli Actuator Range

Current Draws (actuator) (Nick)

When it comes to current draws, the overall braking system will exhibit similar power draws to the remote with the added load of an actuator. Based on the actuator benchmarks, a safe, relatively "worst-case" assumption would be a 12V actuator that draws 12A under maximum load. This would be a situation where the rider is pedaling at maximum force against the actuator's braking mechanism.

Two 6V RHINO lead-acid batteries with 13000 mAh capaticy in a series configuration would be able to fully power the actuator under constant full load for approximately 1 hour 5 minutes.

Four 3.6V Samsung Lithium Ion batteries with a 2500 mAh capacity in series configuration would be able to fully power the actuator under constant full load for approximately 12 minutes.

For a more realistic scenario, different very generous assumptions are made.

Under these assumptions, 10*12 = 120 total seconds of full load draw per hour.

Current Draws (remote) (Nick)

Remote drain calculations

Remote drain calculations

Information Density and Data Transfer Throughput (Nick)

5 bytes * 8 bits per byte * 120Hz = 4800 bits/second of data throughput, or 4.8kb/s.

Wireless radios operating in the MHz range typically operate with throughputs in the megabit, or thousands of kilobits range.

Systems Architecture (Gabe)

Safe Stop Systems Architecture

Safe Stop Systems Architecture

Standards (Gabe)

Standards used to generate testing metrics

Standards used to generate testing metrics

Designs

Frame CAD (Steven)

Main Tricycle Frame

Frame Drawing

Main Tricycle Frame

Rear Frame

Rear Frame

Rear Frame

Remote CAD (Justin)

Remote Concepts

Remote Concept 1 Remote Concept 2 Remote Concept 3

Face Concepts

Remote Face Concepts

3D Prints of remote (Justin)

Square remote 3d print Oval remote 3d print

Plans for next phase

Team Gantt (Justin)

Phase Gantt Chart

Phase Gantt Chart

Individual Plans


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