To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.roboticsOpen lugnet.robotics in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 Robotics / 18312
18311  |  18313
Subject: 
Re: optical mouse chips as vision sensors?
Newsgroups: 
lugnet.robotics
Date: 
Tue, 9 Jul 2002 03:16:29 GMT
Original-From: 
Mike Payson <mpayson@dawgdayz#StopSpammers#.com>
Viewed: 
1991 times
  
Nevermind... I was assuming it would be mounted to the left or right of center
(thus the rotation would still show up as forward or reverse). After thinking
about it a moment, it occurs to me that by mounting the sensor in front of or
behind the axis rotation will show up as left or right motion.

On Monday 08 July 2002 08:02 pm, Mike Payson wrote:
> On Monday 08 July 2002 09:36 am, Steve Baker wrote:
> > Laszlo Meszaros (ETH) wrote:
> > > Keep in mind that the optical mouse chip detects skidding of the mouse
> > > forward - backward - left - right. When fixed on the bottom of a lego
> > > car it will never send signals about moving left and right. As fine as
> > > I can emulate a lego car-like movement with my optical mouse it sends
> > > only forward and backward movement signals.
> > 
> > Right - you only get translational motion - not rotation.  However, you
> > could use two of these contraptions - on on each side of the robot (or
> > one on the front and the other on the back) and thus derive the
> > rotational speed from the difference in translational output from the two
> > mouse chips.
> > 
> > I think you could also do this correctly with a single sensor (for a
> > typical two-wheel-plus-caster/skid robot) if you mounted it far from the
> > center of rotation of the robot.  Then, the lateral motion of the mouse
> > chip would give you a pretty accurate idea of the rotational speed of
> > your robot.
> 
> Hmmm... I don't see how that would work. How would a single sensor be able
> to differentiate between rotational movement and straight forward & back
> movement? I suppose you would be able to guess since you would know what
> state the robot was in at any time (turning or straight), but it seems that
> this would introduce a rather large margin of error. Or am I missing
> something?

--
Mike Payson  |  DawgDayz Dog Walking & Pet Sitting
(206) 280-7295 | www.dawgdayz.com | mpayson@dawgdayz.com



Message has 1 Reply:
  Re: optical mouse chips as vision sensors?
 
(...) Yes - mathematically, you could still do it with the mouse sensor off to the side of the robot (but not with it dead center between the wheels) - however the sensitivity of the chip to small lateral movements probably wouldn't be enough to (...) (24 years ago, 9-Jul-02, to lugnet.robotics)

Message is in Reply To:
  Re: optical mouse chips as vision sensors?
 
(...) Hmmm... I don't see how that would work. How would a single sensor be able to differentiate between rotational movement and straight forward & back movement? I suppose you would be able to guess since you would know what state the robot was in (...) (24 years ago, 9-Jul-02, to lugnet.robotics)

5 Messages in This Thread:


Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact

This Message and its Replies on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR