[Robotgroup] FW: Intro to RG

[Jay Mackey]

Paul,

ARM Automation isn't related to anything else.

We use various industrial sensors, and the cheapest simple distance sensor
using laser time-of-flight is about $500 from SICK, but a more robust
version is $800 from Banner.  The SICK version would flake-out when it
passed over shiny cellophane tape.  For a scanning laser that can provide a
quick laser pattern over almost 180 deg., SICK offers one for several
thousand.  If anyone has seen the DARPA contest vehicles that race
autonomously across the Baha, many of them are studded with numerous laser
scanners made by SICK.  We've used them on a mobile industrial robot
platform as both an obstacle sensor and a form of safety scanning,
preventing anyone from walking up to the robot's reach zone.

We also have used ultrasonic sensors for distance sensing.

I've used vacuum sensors to tell if the vacuum gripper has picked up an
object, force or pressure transducers to tell if the robot is pressing on
something, or to gauge the pressure being applied, accelerometers to verify
or measure the acceleration applied to a product, simple hall-effect,
inductive and capacitive sensors to detect actuator position, optical
through-beams or retro-reflective sensors to detect product, and machine
vision systems (packaged smart-cameras or PC-based vision software).

Most commonly, industrial sensors work off of and sink or source 24VDC out
as this is the most common voltage level for industrial I/O.  Internally,
most are composed of TTL circuitry with opto-isolators to go from TTL to
24VDC out.

The most versatile industrial sensor is a good vision system, but industrial
vision systems are usually targeted toward certain tasks, and the good ones
will still run at least $6000 or $7000 for software and hardware.  So they
end up being used only when absolutely necessary.  You can buy a lot of
simple sensors for $6K.  None of the industrial vision systems could easily
be adapted to mobile robot guidance.  Finding parts and inspecting them is a
totally different task from robot guidance.  Most industrial systems expect
the lighting to be perfect for the task, and don't provide many tools that
could be used to guide a robot in general lighting conditions.

Looking for something that could be use with the NXT, I just found
RoboRealm, http://www.roborealm.com/help/index.php, which appears to provide
most of the basic and more advanced image manipulation tools required, but
it would still be up to the user to provide specific code to interpret the
image and produce guidance controls.  However, they do provide a tutorial
and a Lego NXT software module to communicate with and control the NXT over
Bluetooth in conjunction with the results of processing the camera images.
This module is nice in that it either allows the PC program to totally
control and the NXT and read data from any NXT sensors, OR simply pass
navigation data to a running program in the NXT.  RoboRealm can also be
extended with scripting or add-on DLL programming so that the user can add
their own vision subroutines.  The example robot has a wireless camera
mounted on it and it scans for a blue ball, moves to it and grabs it, and
then scans for a red cone, moves to it, and finally releases the ball at the
red cone.  Some cool video here:
http://www.roborealm.com/tutorial/ball_picker/slide100.php

RoboRealm also can be used with Lego RIS 1.1 (?) and 2.0.



Jay 


-----Original Message-----
From: Paul Atkinson [mailto:pma32904 at yahoo.com] 
Sent: Tuesday, January 23, 2007 9:25 AM
To: The Robot Group Mailing List
Subject: Re: [Robotgroup] Intro to RG

Hi Jay,

I missed meeting you at the last RG meeting. I'm usually a late arrival on
Thursdays due to other commitments. I'm the person Vern asked for an
estimate on doing a custom PCB for interfacing the Soundgin with a Basic
Stamp. If I knew a bit more about the Lego NXT interface, I'd consider
looking into trying the Soundgin adapter you mentioned for that too.

I looked at the ARM Automation site yesterday after seeing your post on
Soundgin. Is ARM Automation related to ARM microprocessors?

I'm interested in learning some more about the sensors used on actual robot
work cells as opposed to those used on small mobile robots. I'd be willing
to discuss a time of flight sensor.

Paul Atkinson

----- Original Message ----
From: Jay Mackey <jay.mackey at armautomation.com>
To: Robot Group <robotgroup at puremagic.com>
Sent: Monday, January 22, 2007 2:27:52 PM
Subject: [Robotgroup] Intro to RG

Hi group,

I visited the meeting on Jan 18.

...