ROLLERBLADE BRAKING SYSTEM Design Team #11 1

 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 3

Introduction 4 Existing DesignProposed Design

Areas of Improvement  Balance and Stability  Difficulty/Technique  Pad Wear and Lifetime  Stopping Distance inline-skates/ 5

Requirements of Proposed Design Design Requirements 6

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 Support Wheel Frame and Assembly Brake Actuator and Application Control Unit Selected Design 8

Foot Support  Ability to attach over existing footwear  Modified existing snowboard binding  Added third strap  Added additional padding and support 9

Wheel Frame  Housing for all components of the skate  ⅛ ” Aluminum welded to form channel  Dimensioned to incorporate range of shoe sizes 10

Wheel Assembly  Axles  All rotating pieces  Bearings  Wheels  Brake rotors 11

Brake Application Brake Actuator Braking Unit 12

Brake Application  Two Avid Juicy III hydraulic calipers  One actuating piston  Two custom made stainless steel disc brake rotors 13

Brake Actuator 14  DC Electric Motor  Planetary Gear Box  Power Screw  Slider Nut  Hydraulic Piston  Piston Plunger

Handheld Controller Skate Circuit Control Unit 15

Handheld Controller  Controls braking force  Wireless  Adapted slot car remote  Added rapid prototyped box  Inserted solid state circuitry 16

Handheld Circuit 17

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 18

Skate Circuit 19

Arduino Microprocessor 20  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

Brake Force Calculations Motor and Power Screw Torque Calculations Hydraulics Calculations Engineering Calculations 21

Brake Torque Calculations 22

Disk Brake Calculations 23

Power Screw Calculations Power Screw Specs Output Force Output rpm Output Rev/s Torque N*m Torque in*lb Thread Type ¼-20 LH Force LbForce N Required Actuating Force = 78.5N 24

Hydraulic Calculations  One piston For two Calipers  Piston Displaces 1.75ml for a 1” stroke  Maximum Allowable Clearance = 1.4mm 25

Initial Budget Final Cost Budget 26

27 Initial Budget 1 Braking, 1 Non-braking DescriptionQtyUnit PriceTotal PriceTotals Roller Blade Prototype1$ Attachment screws and bolts1$20.00 ratchet straps6$9.99 $59.94 strap buckle6$12.99 $77.94 axle rod1$6.50 square channel1$20.00 plastic foot support2$45.00 $ x 90mm wheels with bearings1$79.99 Section Sub-Total $ Braking Planetary gear and power screw motor1$35.55 Rotor2$10.00 $20.00 Hydraulic brake caliper with lever controlled piston1$ Hydraulic brake caliper1$80.00 Hydraulic fluid1$20.00 Section Sub-Total $ Wireless Controller Transmitter1$40.00 Receiver1$40.00 Micro Controller1$ Motor Controller1$50.00 Section Sub-Total $ Safety Equipment Helmet1$29.99 Mouth guard1$10.00 Section Sub-Total $39.99 Power source battery pack and charger for actuator motor1$ AA batteries for wireless controller1$20.00 Section Sub-Total $43.99 Total Summary sub total $1, % tax $ % miscellaneous $ final total $1,330.74

28 Final Cost DescriptionQtyUnit PriceTotal PriceTotals RollerbladeWheels1$50.84 Wheel Frame, Axel Rod, Steel and Aluminum1$58.76 Bolts and Fasteners1$8.77 5/16" Snap Rings1$12.20 Electronics Isolator Pad1$9.61 Acetone1$7.79 Section Sub-Total $ BrakingPlanetary Gear Motor W/RS-3701$50.31 Motor 2 (Brushless)1$24.84 Motor 31$67.77 Motor 41$7.90 Avid Juicy 3 Hydraulic Brake Caliper Kit2$96.05$ /16" Hydraulic T-Fitting1$7.16 Hydraulic fluid1$7.90 Section Sub-Total $ Wireless ControllerSFE Maxstream 1mW XBEE Transciever w/ SFE XBee Explorer Regulated Base 2$43.61 $87.22 Arduino Duemilanove USB Microcontroller1$37.06 Pololu High Power Motor Controller 9A1$ Miscellaneous Electrical Components1$ Variable Resistors3$8.28$24.84 Force Sensor1$ Hand Controller Frame1$47.22 Section Sub-Total $ Power Sources9V Batteries12$3.81$ V Battery Pack w/ Charger1$22.59 Section Sub-Total $68.34 Foot SupportSnowboard Bindings1$55.37 Ratchet Straps and Buckles1$13.57 Boot Wrapping1$39.55 Leg Padding1$6.59 Section Sub-Total $ Total SummaryGrand Total $1, Final Cost

Slider Nut Testing Force Sensor Testing PID Tuning Initial and Final Brake Testing Testing 29

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 30

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 31

PID Tuning  Tuned mainly by Trial and Error  Tuned to:  Maximize Speed Response Time  Minimize Steady-State Error Oscillations Transient Error 32

Braking Test m13 m 10 m in 1.8 sec = 20km/hr Original Stopping Distance

Stopping Distance Tests 34

Weighted (225lb) User Tests 35

Initial Testing  Maximum speed: 30km/h  Average stopping distance from 20km/h: 13m Stopping Distances from 20km/h JamieDimaJeffSean Trial #1 13.2m14.6m14.5m12.6m Trial #2 13.1m13.9m13.6m12.9m Trial #3 12.5m12.9m13.5m12.6m Trial #4 12.2m13.3m12.5m Average12.8m13.7m13.5m12.7m Average Group Stopping Distance13.2m 36

Final Testing Stopping Distances from 20km/h JamieDimaJeffSean Trial #1 10.2m10.6m9.8m Trial #2 8.7m10.9m8.3m7.8m Trial #3 8.4m10.5m11.2m8.4m Trial #4 6.7m9.3m7.5m7.1m Average8.5m10.3m9.2m8.3m Average Group Stopping Distance9.1m  Average stopping distance from 20km/h: 9.1m  Improved braking distance by 4.1m  Maximum speed: 27km/h 37

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 38 RequirementHow it was met

Areas for Future Improvement Further Recommendations 39

Further Recommendations 40  Brushless DC Motor  Faster Motor  Smaller Brake Calipers

How It Works Final Product Conclusion 41

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) 42

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) 43

Final Product 44

Shell Canada Cyclesmith The Binnacle Dr. Robert Bauer Dr. Ken Wilkie Jonathan MacDonald Albert Murphy Angus McPherson Mark MacDonald Special Thanks To: 45

Questions? 46