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 / 22095
22094  |  22096
Subject: 
Re: Balancing robots
Newsgroups: 
lugnet.robotics
Date: 
Thu, 22 Jan 2004 14:41:52 GMT
Viewed: 
1133 times
  
In lugnet.robotics, PeterBalch <PeterBalch@compuserve.com> wrote:

Steve: From reading your code, it seems that you "recalibrates" the "zero"
point very so often by assuming that the bot is vertical. So slow changes
in reflectivity shouldn't matter.

I've only been working with simulations so far. It really helps me
understand what terms are important in the feedback loop. (The Delphi code
is available to anyone who wants it.)

When trying to balance, there are really just two questions to ask.
1) Is the current angle/tilt/distance-to-floor changing?
2) Are the wheels turning?

If you answer no to both, you are balanced.  It really doesn't matter what the
distance-to-floor is.

One thing most people don't understand about Legway is that it WILL balance on a
hill, because it's not trying to adjust to a single value.  It's trying to
adjust so (1) the sensors are not changing and (2) the motors are not being
driven.

This is where there is a difference between motor commands, and connecting a
wheel encoder.  When it's on a slope, it sends "stop" commands to the wheels, so
it thinks it's stopped, but in fact gravity is causing it to roll down the hill.
But that's a different subject.

So, to balance, all you need to do is detect if the tilt angle of the robot is
changing.  If it is, you need to drive the motors.

If it isn't changing, but you're driving the motors, you need to drive them a
bit more to 'right' yourself.

Also, the more it's changing, the more you need to drive the motors.

Steve



Message is in Reply To:
  Re: Balancing robots
 
Allen / Steve (...) using an offset. (...) Steve: From reading your code, it seems that you "recalibrates" the "zero" point very so often by assuming that the bot is vertical. So slow changes in reflectivity shouldn't matter. I've only been working (...) (21 years ago, 22-Jan-04, to lugnet.robotics)

2 Messages in This Thread:

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

Custom Search

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