Hi,

im currently in my final year of a mechanical engineering degree and our final year project is to design and build a smart electric wheelchair, capable of being controlled by a person using only finger movements.

we have developed the control system using an arduino micro-controller, and integrated it successfully into a small-scale robot using two small 12V motors utilising a differential drive method of motion control, and a motor driver based on the L298N chipset from rcubestation.com:

http://www.rcubestation.com/r3cart/index.php?route=product/product&path=59_68&product_id=75

my question is about the best way to now advance the project to a full-scale wheelchair.

having a mostly mechanical background, we have not covered that much material on DC motors, so i am looking for advice on the kinds of motors we should be looking to buy for this application, what kind of drivers we should use (im assuming the L298N is not going to be powerful enough) and any general advice people can give on motor attachment or any other aspect to do with the project.

As this project is not actually going to used by a disabled person for extended periods of time, and cost is a very large factor (we are only 2 poor uni students); the more economical, the better.

any information would be greatly appreciated

thanks
gus

 

I know a lot of your robot-building colleagues might have great advice. I gather wheelchair technologies (batteries, motors, gearbox, driveshaft, etc.) are a starting point for many killer bots. You might be able to get your hands on some of that stuff for little cash if you can find the right folks.

 

Depending on the load the wheelchair may have to carry, you will need some pretty strong gearbox DC motors, preferably 24 volt ones. Like these ones on ebay http://www.ebay.com/itm/Invacare-WH...aultDomain_0&hash=item43b0598c7b#ht_907wt_174

And the L298 WILL not handle these so you will need to have some kind of high current driver circuits, or a compatible H-Bridge circuit to control each motor, you can use the LMD18201T 3A, 55 volt h-bridges.