Senior Design Final presentation_stair-climbing wheelchair device

Design, fabricate, test and validate a device attached to a wheelchair to ascend and descend staircases

1. Stair-Climbing Wheelchair Device ( PR06_team2) Abou Kouyate MEM Bin Li MEM Iatchi Sin MEM Shadrach Golay ECE Yadira Mejia MEM Faculty Advisor: Dr. Jonathan Awerbuch 1 Team members:

2. Team Members 2 Iatchi Sin (MEM) Mechanism Design and Prototype Product Design and Development Denzel Golay (ECE) Circuit board design and Programming Electronic Troubleshooting Bin Li (MEM) Components sourcing and load calculation Plumbing, Fire protection drafting Yadira Mejia (MEM) CAD prototype simulation and project management HVAC Drafting Abou. D Kouyate (MEM) Hardware selection and structure design Structural Engineer

3. Outline Previous Term s Improved Design Solution 3 Fall Term Winter Term

4. 4 Fall Term Goal: Design, fabricate, test, and validate a device attached to a wheelchair to ascend and descend staircases Research Existing Models: iBOT B-Free Chair

5. 5 Fall Term Proposed Design: Approach No. 3 -- 5 spokes hydraulic cylinder wheels Approach No. 4 -- retractable teeth on big wheel s

6. 6 Fall Term Prototype: Geometry of wheels Size requirement Stability Power requirement F T Rear Wheel FBD ∑M: T = F x r = 188Nm = 138.66 lbft Rotation speed = 40rpm Power = 138.66 x 40 / 5252 = 1.06 hp Calculation:

7. Components Overview Bearing pillow block (x4) Shaft coupling (x4) Electric Jack (x2) Aluminum welded wheel and shaft (x4) Aluminum alloy Gearbox (x1) Motor (x1) Battery (x1) Motor (x2)

8. Scissor Jack Platform Aluminum welded Wheel and Shaft Rotating Support Bearing Pillow Block Motor Open Beam Winter Term Carriage (Exploded View)

9. 9

10. Outline Previous Term Improved Design Solution 10 Concerns Posed by Committee from Winter Term Final CAD Model ¼ Scale Prototype Prototype Demonstration

11. Concerns Posed by Committee from Winter Term The platform is too steep for wheelchair to go up. The ADA standard slope ratio is 1:12 Too Steep!

12. Reverse ramp ascent by wheelchair Three ratios (1:12, 1:8, 1:6) 5 times for each angle and take the average 3 different body types (weight, height, gender, age) 12 12 1 8 1 6 1 Slope Experiment ADA Standard

13. 13 Slope Experiment Dimension: 0.84m Different angle moving backward Forward and rotate after landing

14. Experiment Result 14 Slope Experiment Slope angle (ratio) (vertical versus horizontal) Average Time(s) Difficulty level (0=least,3=most) Average Time(s) Difficulty level (0=least,3=most) Average Time(s) Difficulty level (0=least,3=most) 1:6 14 3 16 3 20 3 1:8 5.5 1 6.8 1 7.5 1 1:12 4.5 5.5 6.2 1 1:6 is the steepest slope that the users can go up comfortably 0.84m

15. Independent Variables: Steps height Angle of the steps Friction of the wheels Length of the carriage Weight of the wheelchair and user 15 Concerns Posed by Committee from Winter Term

16. ADA Standard 16 Step Height and Angle Maximum riser (4”) Minimum tread (11”)

17. Friction Stairs 17 The stairs without carpet has small friction and wheelchair is hard to climb The stairs with carpet has increased friction and wheelchair is easy to climb stair

18. Slope and length change of the model Decrease the slope to … accordingly to the result of the experiment Increase the distance between the wheels to enable 90 degree turn after landing 18 Final CAD Model

19. 19

20. 20

21. 21 Final CAD Model Simulation

22. 22 Final CAD Model Simulation

23. The toy wheelchair used is close to ¼ of a standard wheelchair 23 Why ¼ Scale?

24. Main Components Overview Battery Box Holder (x5) Recharge Batteries (x20) Toy Wheelchair Motor Shaft Coupling Joint Bearing Pillow (x4) Wheel Materials Mini Motor ( x2) Open Beam Plywood

25. 25 Purchased items Quantity Cost Battery Charger and Batteries 2 $72.05 Motor 1 $63.99 Coupling 2 $13.06 Wheel Material 1 $19.92 plywood for steps model 1 $24.25 stepper motor for scissor and lock 4 $56.95 Bearing Pillow 2 $11.96 switches 1 $10.00 gyroscope 1 $7.01 stepper motor for hinge 1 $14.90 battery holder 1 $26.81 beam for wheel 1 $40.00 Open beams, screws and nuts 1 $48.61 H-Bridge 1 $11.42 Hinge 1 $4.70 wood for staircase box 1 $54.06 Total cost $479.69 Total Expense

26. 26 ¼ Scaled Carriage

27. 27 ¼ Scaled Carriage (Horizontal system)

28. Q&A 28

29. 29

30. 30

31. 31

32. Calculation at instant of climbing up a step (max torque required) Rear wheel drive, 80% of total weight at rear whee l W = total weight x 80% = 185kg x 80% = 148kg r = 0.13m ∑ Fy : F = W ∑M: T = F x r = 188Nm = 138.66 lbft Rotation speed = 40rpm Power = 138.66 x 40 / 5252 = 1.06 hp 32 W F T Specification requirement for motor and gearbox Rear Wheel FBD

33. 33 Prototype Demonstration