View Single Post
  #9   Spotlight this post!  
Unread 06-12-2007, 15:50
Alex.Norton's Avatar
Alex.Norton Alex.Norton is offline
Fidgetting
no team
 
Join Date: Apr 2005
Rookie Year: 2003
Location: Ft. Collins, Colorado
Posts: 190
Alex.Norton has much to be proud ofAlex.Norton has much to be proud ofAlex.Norton has much to be proud ofAlex.Norton has much to be proud ofAlex.Norton has much to be proud ofAlex.Norton has much to be proud ofAlex.Norton has much to be proud ofAlex.Norton has much to be proud of
Send a message via AIM to Alex.Norton Send a message via MSN to Alex.Norton
Re: How do you sync multiple motors?

Quote:
Originally Posted by TubaMorg View Post

Another sort of wacky way we've played with works, but is more useful as an exercise than a practical way of controlling your robot. After we put our robot together, we used a strobelight tachometer and got the wheel speed of each wheel at each PWM value. We input this data into a spread sheet and plotted the results to visualize the curve. These data form the power curve for each wheel and includes losses to the power train. From this you can calculate an equation for each side that coverts pwm value to speed so that each wheel recieves the appropriate pwm input for a desired wheel speed.
This only works if the surface your driving on is consistent. If there are any variation such as from free spinning, to carpet, to concrete you will see large differences. There can even be large difference between on spot on a carpt and another. Say something sticky was spilled, the wheel that passes over it will drive at a different speed compared to the same wheel on non sticky carpet. Of course first fields are fairly consistent but if someone drops a part on the field this will affect a drivetrain that doesn't have feed back.

Alex