ROLLERBLADE BRAKING SYSTEM

Design Team #11

1

Design Team #11

Team Members:

Sean Milley

Jamie Zwicker

Jeffrey Aucoin

Dima Eshtaya

Team Supervisor:

Dr. Robert Bauer

2

Presentation Overview

Introduction Existing Design Design Requirements Selected Design and Manufacturing Engineering Calculations Budget Testing Further Recommendations Conclusion Questions

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Introduction4

Existing Design Proposed Design

http://www.jacqdesign.com/img/blog/photos/RollerbladeCrossfire4D.jpg

Areas of Improvement

Balance and Stability

Difficulty/Technique

Pad Wear and Lifetime

Stopping Distancehttp://www.skatescool.com/inline-skating/learn-how-to-t-stop-on-inline-skates/

5

Requirements of Proposed Design

Design Requirements6

Design Requirements

1. Removable

2. Support a 225lb user

3. Improved braking distance

4. Maintain mobility/stability

5. Increased lifetime

6. Serviceable

7. Weather Resistant

7

Foot SupportWheel Frame and AssemblyBrake Actuator and ApplicationControl Unit

Selected Design8

Foot Support

Ability to attach over existing footwear

Modified existing snowboard binding

Added third strap

Added additional padding and support

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Wheel Frame

Housing for all components of the skate

⅛” Aluminum welded to form channel

Dimensioned to incorporate range of shoe sizes

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Wheel Assembly

Axles

All rotating pieces

Bearings

Wheels

Brake rotors

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Brake ApplicationBrake Actuator

Braking Unit12

Brake Application

Two Avid Juicy III hydraulic calipers

One actuating piston

Two custom made stainless steel disc brake rotors

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Brake Actuator14

DC Electric Motor

Planetary Gear

Box

Power Screw

Slider Nut

Hydraulic Piston

Piston Plunger

Handheld ControllerSkate Circuit

Control Unit15

Handheld Controller

Controls braking force

Wireless Adapted slot car

remote Added rapid

prototyped box Inserted solid

state circuitry

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Handheld Circuit17

Skate Unit

Receives remote input XBee Transceiver

Acts as PID controller Arduino Duemilanov

Microprocessor Force sensor feedback

Controls motor Pololu High Power

Motor Controller Speed and Direction

Generates brake force Motor pushing piston

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Skate Circuit19

Arduino Microprocessor20

Reads in PWM from XBee Converts to percent

Reads in analog feedback from Force Sensor Converts to percent

Calculates error Implements Digital PID

Control Sends Motor Controller

commands speed and direction

http://blog.makezine.com/arduino_duemilanove_redo.jpg

Brake Force CalculationsMotor and Power Screw Torque CalculationsHydraulics Calculations

Engineering Calculations21

Brake Torque Calculations22

Disk Brake Calculations23

Power Screw Calculations

Power Screw Specs

Output Force

Output rpm

Output Rev/s

Torque N*m

Torque in*lb

Thread Type

444 7.41.45

412.8

69¼-20

LH

Force Lb

Force N

161.9

720.1

http://www.roton.com/application_engineering.aspx

Required Actuating Force = 78.5N

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Hydraulic Calculations

One piston For two Calipers

Piston Displaces 1.75ml for a 1” stroke

Maximum Allowable Clearance = 1.4mm

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Initial BudgetFinal Cost

Budget26

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Initial Budget1 Braking, 1 Non-braking

  Description Qty Unit Price Total Price

Totals

Roller Blade Prototype 1 $100.00 $100.00    Attachment screws and bolts 1 $20.00 $20.00    ratchet straps 6 $9.99 $59.94    strap buckle 6 $12.99 $77.94    axle rod 1 $6.50 $6.50  

square channel 1 $20.00 $20.00    plastic foot support 2 $45.00 $90.00  

8 x 90mm wheels with bearings 1 $79.99 $79.99  Section Sub-Total         $454.37Braking Planetary gear and power screw motor 1 $35.55 $35.55    Rotor 2 $10.00 $20.00    Hydraulic brake caliper with lever controlled piston 1 $150.00 $150.00    Hydraulic brake caliper 1 $80.00 $80.00    Hydraulic fluid 1 $20.00 $20.00  Section Sub-Total         $305.55Wireless Controller Transmitter 1 $40.00 $40.00    Receiver 1 $40.00 $40.00    Micro Controller 1 $108.00 $108.00    Motor Controller 1 $50.00 $50.00  Section Sub-Total         $238.00Safety Equipment Helmet 1 $29.99 $29.99    Mouth guard 1 $10.00 $10.00  Section Sub-Total         $39.99Power source battery pack and charger for actuator motor 1 $23.99 $23.99    16 AA batteries for wireless controller 1 $20.00 $20.00  Section Sub-Total         $43.99Total Summary sub total       $1,081.90  13% tax       $140.65  10% miscellaneous       $108.19

 

final total

     

$1,330.74

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Final Cost Description Qty Unit Price Total Price TotalsRollerblade Wheels 1 $50.84 $50.84 Wheel Frame, Axel Rod, Steel and Aluminum 1 $58.76 $58.76 Bolts and Fasteners 1 $8.77 $8.77 5/16" Snap Rings 1 $12.20 $12.20 Electronics Isolator Pad 1 $9.61 $9.61 Acetone 1 $7.79 $7.79 Section Sub-Total $147.97Braking Planetary Gear Motor W/RS-370 1 $50.31 $50.31 Motor 2 (Brushless) 1 $24.84 $24.84 Motor 3 1 $67.77 $67.77 Motor 4 1 $7.90 $7.90 Avid Juicy 3 Hydraulic Brake Caliper Kit 2 $96.05 $192.10 3/16" Hydraulic T-Fitting 1 $7.16 $7.16 Hydraulic fluid 1 $7.90 $7.90 Section Sub-Total $357.98Wireless Controller SFE Maxstream 1mW XBEE Transciever w/ SFE XBee Explorer

Regulated Base2 $43.61

$87.22 Arduino Duemilanove USB Microcontroller 1 $37.06 $37.06 Pololu High Power Motor Controller 9A 1 $122.31 $122.31 Miscellaneous Electrical Components 1 $143.56 $143.56 Variable Resistors 3 $8.28 $24.84 Force Sensor 1 $130.05 $130.05 Hand Controller Frame 1 $47.22 $47.22 Section Sub-Total $592.26Power Sources 9V Batteries 12 $3.81 $45.75 7.2V Battery Pack w/ Charger 1 $22.59 $22.59 Section Sub-Total $68.34Foot Support Snowboard Bindings 1 $55.37 $55.37 Ratchet Straps and Buckles 1 $13.57 $13.57 Boot Wrapping 1 $39.55 $39.55 Leg Padding 1 $6.59 $6.59 Section Sub-Total $115.08

Total Summary Grand Total $1,281.63

Final Cost

Slider Nut TestingForce Sensor TestingPID TuningInitial and Final Brake Testing

Testing29

Slider Nut Tests

Nylon nut striped at 2.48Nm Motor Torque =

1.45Nm Original nut

stripped during application

Inserted brass threads in nut to rectify the issue

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Force Sensor Tests and Calibration Made testing

apparatus Loaded force sensor

No load 20lb 70lb 120lb

Tested Resistance

(Multimeter) Voltage Output

(Oscilloscope) Tuned circuit

Maximum Motor Output = Maximum Sensor Output

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PID Tuning

Tuned mainly by Trial and Error

Tuned to: Maximize

Speed Response Time

Minimize Steady-State Error Oscillations Transient Error

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Braking Test33

10 m 13 m

10 m in 1.8 sec = 20km/hr Original Stopping Distance

Stopping Distance Tests34

Weighted (225lb) User Tests

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Initial Testing

Maximum speed: 30km/h

Average stopping distance from 20km/h: 13m

Stopping Distances from 20km/h  Jamie Dima Jeff SeanTrial #1 13.2m 14.6m 14.5m 12.6mTrial #2 13.1m 13.9m 13.6m 12.9mTrial #3 12.5m 12.9m 13.5m 12.6mTrial #4 12.2m 13.3m 12.5m 12.5m

Average 12.8m 13.7m 13.5m 12.7mAverage Group Stopping Distance

13.2m

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Final Testing

Stopping Distances from 20km/h  Jamie Dima Jeff SeanTrial #1 10.2m 10.6m 9.8m 9.8mTrial #2 8.7m 10.9m 8.3m 7.8mTrial #3 8.4m 10.5m 11.2m 8.4mTrial #4 6.7m 9.3m 7.5m 7.1m

Average 8.5m 10.3m 9.2m 8.3mAverage Group Stopping Distance 9.1m

Average stopping distance from 20km/h: 9.1m

Improved braking distance by 4.1m

Maximum speed: 27km/h

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Requirements Met

1. Removable

2. Support a 225lb user

3. Improved braking distance

4. Maintain mobility/stability

5. Increased lifetime

6. Serviceable

7. Weather Resistant

1. Snowboard Binding

2. Weight Test

3. Braking Test

4. Wireless

5. Mountain Bike Brake Pads

6. Bolts and Snap Rings

7. Calking and Plexi-Glass

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Requirement How it was met

Areas for Future Improvement

Further Recommendations39

Further Recommendations40

Brushless DC Motor Faster Motor Smaller Brake Calipers

How It WorksFinal Product

Conclusion41

How It Works

User pushes down on handheld remote Varying the voltage

to the XBee (0-3.3V) XBee sends wireless

signal XBee receives

signal in skate Outputs PWM (0-

3.3V)

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How It Works (Continued)

Arduino reads in XBee signal and force sensor feedback Coverts both to a

percentage Determines error Implements digital PID

control Sends signal to the

motor controller (4 Byte string)

Motor Controller receives data string Operates motor Force sensor feedbacks

analog voltage to Arduino (0-5V)

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Final Product44

Shell CanadaCyclesmithThe BinnacleDr. Robert BauerDr. Ken WilkieJonathan MacDonaldAlbert MurphyAngus McPhersonMark MacDonald

Special Thanks To:45

Questions?46