P14007: Wheelchair Assist Final Presentation Che-An Lee Industrial - PowerPoint PPT Presentation

P14007: Wheelchair Assist Final Presentation Che-An Lee – Industrial and System Engineer Dan Schuster – Mechanical Engineer Phil Medalie – Mechanical Engineer Tom Elliot – Electrical Engineer Sponsor: Multidisciplinary Senior Design Program

Agenda  Project Description  Design Concept  System Architecture  Project Status  Test Results  Conclusion

Project Description  Design a low cost device that maintain the characteristic of a manual wheelchair and prevent the wheelchair to roll back  Key Customer Needs and Engineering Metrics:

Design Concept Brake Disk Pawl Ratchet Bearing Block Caliper

Design Concept Cont. Brake Disk Pawl Ratchet Bearing Block Caliper

Design Concept Cont. Left Wheel Generator Bridge Rectifier Circuit Breaker Buck-Boost USB Female Zener Regulator Plug Diode Bridge Rectifier Right Wheel Generator

Design Concept Cont. 1. Left Generator Input Banana Clips 2. Right Generator Input Banana Clips 3. Both Bridge Rectifiers 4. Circuit Breaker Switch 5. Zener Diode 6. Buck-Boost Regulator 5 Volts 7. USB out with USB Circuitry.

System Architecture

Project Status  Design meets all customer needs except:  Weight (0.5 lbs over)  Charging system is not on the chair  Unable to test:  Maximum weight at 10 degree incline  Completed BOM for working prototype  Completed all mechanical systems under budget

Test Results Specification Tested Target Value Result Max weight at 10 degree incline 400 lbf 260 lbf Time to disengage 2 sec 3.56 sec Time to engage 0.5 sec 0 sec Max. incline angle 6 ° 13 ° Max. downhill speed 3 mph User Varied Time to disengage 2 sec 0 sec Time to engage 0.5 sec 0 sec Turning radius 1 ft. 0 ft Time to remove system 10 min 6 min Current output at 1mph 0.25 amps 0 amps Current output at 4mph 1 amps 1.04 amps Rollback distance 1 inch 0.25 inches Time (replacement) 15 min 9 min Input force 10 lbf 1.32 lbf System Weight 20 lb 20.5 lb Torque with 5 ohms resistive load 1 lbf 2.72 lbf Total System Cost (Purchased Parts) $500 $438 Wheelchair Width when folded 18 inches 17 inches Wheelchair Width 29 inches 25.5 inches Wheelchair Length 40 inches 38.5 inches

Conclusion Current Results: Future Work:  Demonstrated a cost Weight reduction  effective solution for Universally adaptable to  rolling backwards most manual wheelchairs  Design maintains Incorporate movement  important characteristics of assist into design a manual wheelchair More efficient generator   Generator system system to charge batteries succeeded in charging a at lower speeds battery

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