1
ROLLERBLADE BRAKING
SYSTEM
Design Team #11
Design Team #11
2


Team Members:

Sean Milley

Jamie Zwicker

Jeffrey Aucoin

Dima Eshtaya
Team Supervisor:

Dr. Robert Bauer
Presentation Overview
3










Introduction
Existing Design
Design Requirements
Selected Design and Manufacturing
Engineering Calculations
Budget
Testing
Further Recommendations
Conclusion
Questions
Introduction
4
Existing Design
http://www.jacqdesign.com/img/blog/photos/RollerbladeCrossfire4D.jpg
Proposed Design
Areas of Improvement
5

Balance and Stability

Difficulty/Technique


http://www.skatescool.com/inline-skating/learn-how-to-t-stop-oninline-skates/
Pad Wear and
Lifetime
Stopping Distance
6
Design Requirements
Requirements of Proposed Design
Design Requirements
7
1.
Removable
2.
Support a 225lb user
3.
Improved braking distance
4.
Maintain mobility/stability
5.
Increased lifetime
6.
Serviceable
7.
Weather Resistant
8
Selected Design
Foot Support
Wheel Frame and Assembly
Brake Actuator and Application
Control Unit
Foot Support
9


Ability to attach over
existing footwear
Modified existing
snowboard binding
 Added
 Added
third strap
additional
padding and support
Wheel Frame
10



Housing for all
components of the
skate
⅛” Aluminum welded
to form channel
Dimensioned to
incorporate range of
shoe sizes
Wheel Assembly
11

Axles

All rotating pieces
 Bearings
 Wheels
 Brake
rotors
12
Braking Unit
Brake Application
Brake Actuator
Brake Application
13



Two Avid Juicy III
hydraulic calipers
One actuating piston
Two custom made
stainless steel disc
brake rotors
Brake Actuator
14

DC Electric Motor
 Planetary

Power Screw
 Slider

Gear Box
Nut
Hydraulic Piston
 Piston
Plunger
15
Control Unit
Handheld Controller
Skate Circuit
Handheld Controller
16



Controls braking force
Wireless
Adapted slot car
remote
 Added
rapid
prototyped box
 Inserted solid state
circuitry
Handheld Circuit
17
Skate Unit
18

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
Skate Circuit
19
Arduino Microprocessor
20

Reads in PWM from XBee


Reads in analog feedback
from Force Sensor



http://blog.makezine.com/arduino_duemilanove_redo.jpg

Converts to percent
Converts to percent
Calculates error
Implements Digital PID
Control
Sends Motor Controller
commands

speed and direction
21
Engineering Calculations
Brake Force Calculations
Motor and Power Screw Torque Calculations
Hydraulics Calculations
Brake Torque Calculations
22
Disk Brake Calculations
23
Power Screw Calculations
24
Power Screw Specs
Output
rpm
444
Output
Rev/s
Torque
N*m
Torque
in*lb
Thread
Type
12.86 ¼-20
7.4 1.454
9
LH
http://www.roton.com/application_engineering.aspx
Output Force
Force
Lb
Force N
161.9 720.1
Required Actuating Force = 78.5N
Hydraulic Calculations
25



One piston For two
Calipers
Piston Displaces
1.75ml for a 1” stroke
Maximum Allowable
Clearance = 1.4mm
26
Budget
Initial Budget
Final Cost
Initial Budget
1 Braking, 1 Non-braking
Description
Roller Blade
Section Sub-Total
Braking
Section Sub-Total
Wireless Controller
Section Sub-Total
Safety Equipment
Section Sub-Total
Power source
Section Sub-Total
Total Summary
27
Qty
Unit Price
Total Price
Prototype
Attachment screws and bolts
ratchet straps
strap buckle
axle rod
square channel
plastic foot support
8 x 90mm wheels with bearings
1
1
6
6
1
1
2
1
$100.00
$20.00
$9.99
$12.99
$6.50
$20.00
$45.00
$79.99
$100.00
$20.00
$59.94
$77.94
$6.50
$20.00
$90.00
$79.99
Planetary gear and power screw motor
Rotor
Hydraulic brake caliper with lever controlled piston
Hydraulic brake caliper
Hydraulic fluid
1
2
1
1
1
$35.55
$10.00
$150.00
$80.00
$20.00
$35.55
$20.00
$150.00
$80.00
$20.00
Totals
$454.37
$305.55
Transmitter
Receiver
Micro Controller
Motor Controller
1
1
1
1
$40.00
$40.00
$108.00
$50.00
$40.00
$40.00
$108.00
$50.00
$238.00
Helmet
Mouth guard
1
1
$29.99
$10.00
$29.99
$10.00
battery pack and charger for actuator motor
16 AA batteries for wireless controller
1
1
$23.99
$20.00
$23.99
$20.00
$39.99
sub total
13% tax
10% miscellaneous
final total
$43.99
$1,081.90
$140.65
$108.19
$1,330.74
Final Cost
Rollerblade
Section Sub-Total
Braking
Section Sub-Total
Wireless Controller
Section Sub-Total
Power Sources
Section Sub-Total
Foot Support
Description
Wheels
Wheel Frame, Axel Rod, Steel and Aluminum
Bolts and Fasteners
5/16" Snap Rings
Electronics Isolator Pad
Acetone
Total Summary
Qty
Unit Price
Total Price
Totals
$50.84
1
$50.84
$58.76
1
$58.76
$8.77
1
$8.77
$12.20
1
$12.20
$9.61
1
$9.61
$7.79
1
$7.79
$147.97
Planetary Gear Motor W/RS-370
Motor 2 (Brushless)
Motor 3
Motor 4
Avid Juicy 3 Hydraulic Brake Caliper Kit
3/16" Hydraulic T-Fitting
Hydraulic fluid
1
1
1
1
2
1
1
$50.31
$24.84
$67.77
$7.90
$96.05
$7.16
$7.90
SFE Maxstream 1mW XBEE Transciever w/ SFE XBee Explorer
Regulated Base
Arduino Duemilanove USB Microcontroller
Pololu High Power Motor Controller 9A
Miscellaneous Electrical Components
Variable Resistors
Force Sensor
Hand Controller Frame
2
$43.61
$50.31
$24.84
$67.77
$7.90
$192.10
$7.16
$7.90
$357.98
1
1
1
3
1
1
$37.06
$122.31
$143.56
$8.28
$130.05
$47.22
$87.22
$37.06
$122.31
$143.56
$24.84
$130.05
$47.22
12
1
$3.81
$22.59
$45.75
$22.59
$592.26
9V Batteries
7.2V Battery Pack w/ Charger
$68.34
Snowboard Bindings
Ratchet Straps and Buckles
Boot Wrapping
Leg Padding
1
1
1
1
$55.37
$13.57
$39.55
$6.59
$55.37
$13.57
$39.55
$6.59
$115.08
Section Sub-Total
28
Final Cost
Grand Total
$1,281.63
29
Testing
Slider Nut Testing
Force Sensor Testing
PID Tuning
Initial and Final Brake Testing
Slider Nut Tests
30

Nylon nut striped at
2.48Nm
 Motor
Torque =
1.45Nm


Original nut stripped
during application
Inserted brass threads
in nut to rectify the
issue
Force Sensor Tests and Calibration
31


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
PID Tuning
32


Tuned mainly by Trial
and Error
Tuned to:
 Maximize
 Speed
 Response
Time
 Minimize
 Steady-State
Error
 Oscillations
 Transient
Error
Braking Test
33
10 m
10 m in 1.8 sec = 20km/hr
13 m
Original Stopping Distance
Stopping Distance Tests
34
Weighted (225lb) User Tests
35
Initial Testing
36


Maximum speed:
30km/h
Average stopping
distance from 20km/h:
13m
Stopping Distances from 20km/h
Jamie
Dima
Jeff
Sean
Trial #1
13.2m
14.6m
14.5m
12.6m
Trial #2
13.1m
13.9m
13.6m
12.9m
Trial #3
12.5m
12.9m
13.5m
12.6m
Trial #4
12.2m
13.3m
12.5m
12.5m
Average
12.8m 13.7m 13.5m 12.7m
Average Group Stopping
Distance
13.2m
Final Testing
37
Stopping Distances from 20km/h

Jamie
Dima
Jeff
Sean
Trial #1
10.2m
10.6m
9.8m
9.8m
Trial #2
8.7m
10.9m
8.3m
7.8m
Trial #3
8.4m
10.5m
11.2m
8.4m
Trial #4
6.7m
9.3m
7.5m
7.1m
8.5m
10.3m
9.2m
8.3m
Average
Average Group Stopping
Distance
9.1m


Average stopping
distance from 20km/h:
9.1m
Improved braking
distance by 4.1m
Maximum speed:
27km/h
Requirements Met
38
Requirement
How it was met
1.
Removable
1.
Snowboard Binding
2.
Support a 225lb user
2.
Weight Test
3.
Improved braking distance
3.
Braking Test
4.
Maintain mobility/stability
4.
Wireless
5.
Increased lifetime
5.
Mountain Bike Brake Pads
6.
Serviceable
6.
Bolts and Snap Rings
7.
Weather Resistant
7.
Calking and Plexi-Glass
39
Further Recommendations
Areas for Future Improvement
Further Recommendations
40



Brushless DC Motor
Faster Motor
Smaller Brake Calipers
41
Conclusion
How It Works
Final Product
How It Works
42

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)
How It Works (Continued)
43

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 (05V)
Final Product
44
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Special Thanks To:
Shell Canada
Cyclesmith
The Binnacle
Dr. Robert Bauer
Dr. Ken Wilkie
Jonathan MacDonald
Albert Murphy
Angus McPherson
Mark MacDonald
Questions?
46