Matt Last, Rob VanderVennen, Matt Rozema, Dan Evans

Outline  Project Definition  Design  Final Product  Conclusions  Questions

Introduction  Isaac Postma  Spinal Muscular Atrophy  Physical Limitations  Current Transportation

Project Definition  Design an electric wheelchair that the individual can control while lying down  Two operational modes: Manual (attendant-controlled) Electric (user-controlled)  Touchpad controlled driving system  LED system indicating possible directions  One camera and monitor for user vision

Major Design Decisions  Motor control hardware topology  Feedback type  User interface  Power regulation safety  Structure affected by other component designs  Customer requests

Component Design  Power regulation Fuse Overvoltage protection Cooling fan Heat sinks

Component Design  Motor Control 2 separate motor controllers 1 electronic control unit (ECU)

Component Design  Software User Interface controlled by ECU Directional state machine Closed loop voltage control of motors CAN, UART, GPIO, Timer, and Watchdog peripheral drivers provided by Stellaris

Component Design  Motors Provide necessary torque to move the wheelchair and user Required to handle: ○ 450 lb maximum weight (user + stroller) ○ ± 5° incline/decline ○ 3.5 mph max speed Minimum motor specifications to meet requirements above: ○ Power: hp ○ Torque: 3.22 ft-lb

Component Design  Brakes Electric brakes ○ Controlled by software ○ Triggered by releasing the touch button Mechanical brakes ○ Controlled by attendant pushing wheelchair ○ Consist of hand lever and rim brake (bicycle brake) Parking Brakes ○ Lock each wheel in place ○ Manual lever system Emergency Brake ○ Provide immediate motor stoppage during emergencies ○ Triggered by a simple on-off switch

Component Design  Mounting LCD Touch Button Camera Brakes Motors

Component Design  Structure Adjustable length Storage Material: Aluminum 6063-T6

Final Design

Final Product

Significant Issues  Funds  Schedule  Limited manufacturing capabilities

Conclusion  Interacting with an actual customer  Working with outside companies  Scheduling and budgeting  Documentation and testing  Finalist in RESNA competition

Acknowledgements  Professor VanderLeest  Professor Brouwer  Carole Pettijohn (Ivanrest Church)  Russel Ramsay (Texas Instruments)  Tim Theriault (Industrial Consultant)  Greg Bush (Gentex)  Jim Nammensma (Ebling & Son)

Questions?