WheelChair/Howard Community College/fall2012/p2-503-mcf

Problem Statement

We need to make the wheelchair move around by itself. We want to fix the battery charging issues that the last team had and control the wheelchair with an Arduino. We also need to document all the different parts of the wheelchair (motors, shield, and wires) with any available official documentation and pictures. Finally, we need to find a way to charge the battery of the wheelchair.

Team Members

Akoumany
Cooke
Foley

Summary

Our major goals involved getting the wheelchair functional. We broke the issues down into three portions: the motors, the motor shield, and the batteries.

Poster

Story

We started by doing an extensive search for documentations on all the critical parts of the wheelchair. The motor, shield, and joystick. We found out that one of the members from the previous team came across some useful documentations.

1. 3G Storm Series wheelchair Owner’s Operator and Maintenance Manual.

We also got some pictures of the joystick before it was removed. Hopefully, seeing the original state of the joystick will help later on.

• 
  joystick
• 
  on-and-off switch
• 
  opened joystick
• 
  opened up
• 
  opened up again

Adjustments made to make the terminal cap work with the batteries

The two batteries that came with the chair were no longer holding a charge. The solution within the batteries had probably degenerated over the years to the point at which it was no longer functional. Based on the capabilities of the Howard Community College engineering lab, the old batteries should be recycled. A very generous anonymous donor gave the school three additional 12 volt wheelchair batteries, all of which hold the proper charge. In order to use these batteries, modifications were made to the battery terminals.
For the future needs of this project, the Thunder AC6 charger should be suitable to charge the batteries. It has been left with the wheelchair and batteries within the Engineering lab. A red cable ending in an alligator clip could not be found, so the positive terminal's clip is marked with a piece of red electrical tape.

Motors

Regarding the motor, We had to detach them from the chair itself to get a closer look at both of them. Upon on close inspection, we realized that some parts of the motors were missing, specifically a brush and its plastic cap. Both were later found. We used a crimping tool and some powerpole connectors at the end of a wired that we used to connect the motors to a source of power. You can look at this beautiful series of pictures to learn how the crimping tools works.

Our aim was to supply the motors with some sort of battery and get it to turn. We tried using the batteries that were in the chair but realized that they were both dead. We also tried using some power supplies but the motors still didn't move.

After failing with the original batteries and the power supply, We ended up using the Rigrunner 4012 and Astron V6-36M to power the motor. It worked. Check out the video here.

Material List

Storm: Arrow Power Wheelchair, 2nd Generation (Parts catalog)
12 Volt AGM deep cycle batteries (1 Universal and 2 MK Powered)
Thunder AC6 charger (manual)
Rigrunner 4012
Crimping tool
Powerpole Connectors

Software List

none

Time

44 hours

Tutorials

Battery Changing Tutorial 
  Basic battery glossary (please add to this as needed!)

How To Use The Crimping Tool in pictures

Next Steps

The next steps would be to put this all together to make the chair fully functional.