Go to Post "It's robotics season; I no longer know what sleep is." - StephLee [more]
Home
Go Back   Chief Delphi > Technical > Programming
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
 
 
Thread Tools Rate Thread Display Modes
Prev Previous Post   Next Post Next
  #16   Spotlight this post!  
Unread 10-01-2017, 14:37
Ubiquity Ubiquity is offline
Registered User
FRC #5027
 
Join Date: Jan 2015
Location: United States
Posts: 30
Ubiquity is an unknown quantity at this point
Re: Optical mouse for mecanum Odometry?

The quick answer is many have tried to use optical mice for Odometry, and the consensus is it doesn't work. Commercial robots (Fetch, Savioke) solve SLAM(Simultaneous Location and Mapping) using a variety of techniques combined with odometry. These include lidar, sonar, optical flow, compasses, accelorometers, etc. Some use wifi and optical features (Fiducuals). While odometry is ok for rough distance, it is not so good for determining pose.

It is interesting to consider why this is. Typically, a differential robot is controlled by adjusting the speed of the motors via PID. So getting the robot to go straight in autonomous should be easy (Ha.). Even if you could get motors to respond perfectly to speed commands, wheel alignment, slipping, mechanical differences all conspire to mess with you. Turning is worse. to turn in place with a diff drive, the wheels need to rotate opposite directions simultaneously for preciously .

With good odometry you should be able to get an FRC robot to go forward 10ft within about 6 inches in autonomous. Try to make a 10ft square and see you'll be 3 feet off and turned 30 degrees.
__________________
Former mentor: 255(4y), 254(2y), 668(1y), 751(1y),5027
Current mentor 2854, 5905
Volunteer, Ref, Inspector, Judge, FTA
Nat. Champion 2000(255), Nat. Chairman's 2004(254), SVR Champion 2015(5027)
(Botball N. Champ 2001)
Reply With Quote
 


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 07:03.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi