1. Smart Cane – P14043 Sub Systems Design Review Lauren Bell, Jessica Davila, Jake Luckman, William McIntyre, Aaron Vogel

2. Agenda Project Scope Concept Selection Engineering Requirements Component Breakdown Engineering Analysis Test Plan Risk Analysis Project Plan Audience Feedback Please

3. Project Scope Project Deliverables -Handle that provides directional signals to the user Objects to left or right of userBattery Life for 4-5 hours Comfortable HandleReasonable Cost - Simulation testing device

4. Concept Selection Final Concept Ideas Finger Scroll Palm Roller Palm Roller and Finger Scroll Final Concept Selection Palm Roller without Finger Scroll

5. Engineering Requirements

6. Estimated Power Consumption

7. Design Grip Pressure Spec Ensure handle functions under excessive grip Measure pressure of displaced air for rough idea Median pressure ~3 psi Compare to Grip Pressure Study* FSR sensors on glove “Crush grip” measured on 50mm diameter handle 5 male and 5 female adults Maximum pressure ~3.1 psi Our measurements matched the study, therefore: Marginal Grip Pressure: 3 psi Maximum (Design) Pressure: 5 psi * Tao Guo qiang; Li Jun yuan; Jiang Xian feng, "Research on virtual testing of hand pressure distribution for handle grasp," Mechatronic Science, Electric Engineering and Computer (MEC), 2011 International Conference on, pp.1610,1613, 19-22 Aug. 201

8. Required Motor Torque Worst Case – Excessive grip stalls motor Maximum moment caused by design pressure 50.1 oz-in

9. Motor Type Selection Design Factors to meet Engineering Requirements Rotational speeds of 50 to 70 RPM Commonly available at 50 oz-in DC MotorStepper MotorServomotor Smooth rotationYesNoYes Won’t stall at slow shaft speed NoYes Generally maintains speed under varying grips NoYes Dimensions < 2”No (Gears needed)NoYes Cost < $30Yes Totals2 Yes3 Yes5 Yes

10. Engineering Analysis: Bump Rotation Characteristics Effective haptic zone – lower palm Effective Bump Height Bump Frequency

11. Component Breakdown

12. Bump Rotation/Roller Analysis Bumps per rotation Servo to Roller Spacing Effectiveness of our model – Audience?

13. Roller Force/Stress Analysis

14. Force/Stress Cont’d

15. Roller Assembly Support Elastic Materials Supports Support for Roller Assembly Audience Feedback please

16. Handle Material Selection Desirable Qualities Moisture wicking Higher Coefficient of Friction Possible Options Softex Neoprene Tennis Racquet Handle Cover Top Choice Synthetic Cloth - Nylon Tennis Racquet Handle Cover

17. Handle Weight Estimate ComponentQuantityWeight (grams)Weight (lbs) SpringRC SM-S4303R Servo Motor1410.09 WhataGrip Handle Cover12.80.006 AA Batteries4920.203 Cross-Bar/Plate for Servo2136.10.3 5/16" Ball Bearings48.240.02 MSP430 Microcontroller12.80.006 Total 282.940.625

18. Cost Estimate ComponentQuantityPrice per Item (US Dollars)Total Cost (US Dollars) SpringRC SM-S4303R Servo Motor212.9525.90 Handle Cover22.975.94 Set of Batteries18.00 Cross-Bar/Plate for Servo (Cost of Aluminum) 2"x2"x1' Block123.95 5/16" Ball Bearings411.00 MSP430 Microcontroller25.0010.00 Rocker Switches35.0015.00 Ultrasonic Sensors330.0090.00 Handle Material* White Aluminum Cane127.00 Shipping Costs15.00 Total221.79 *Handle Material has not yet been decided

19. Test Plan

20. Simulation and Detection System

21. Micro Family Selection

22. Risk Assessment IDRisk ItemLikelihoodSeverityImportance 1Burning out micro controller326 2Software is ineffective236 3Haptic handle and testing systems integration issues236 4Not meeting customer expectations236 5Not obtaining parts on time224 6Battery malfunction224 7Over budget224 85 volunteers for user test are not established in time224 9Cane does not stay together, durability failure133 10Not completing software component133 11Haptic forces not being strong enough133 12Hardware and software integration133 13Detection is ineffective133 14Team Member leaves team133 15Cane gets dropped repeatedly on the ground133 16Excessive tapping133 17Handle material is not effective (Tears with consistent wear)133 18Uncoordinated team schedules122 19Selected power and components produce excessive heat122 20Necessary facilities and personnel are not available when needed122 21System is too heavy for desired cane weight111

23. Risk Growth Curve

24. Project Plan

25. Network Diagram

26. Immediate Next Steps Engineering Analysis [ 10/28] Power Requirement Electrical Subsystem [10/31 ] Design power supply Layout sensor, micro and power supply location Estimate weight distribution Pseudo code Mechanical Subsystem [ 10/31] CAD drawings Assembly drawings Select shelf parts Test Plan [ 10/28] Establish and draft test plans Risk Management [Weekly]