|
Posted by Matt Timmermans on October 6, 2005, 9:31 pm
>[...]
> But... suppose you want to build a tethered (remotely powered)
> tunnel crawler to explore and map complex networks of metal piping,
> such as sewers, conduits, and ventilation ducts? Odometry would be a
> bit "sloppy" (especially in sewer pipes), and one couldn't depend on
> light or sound.
Interesting. How about this:
- Put closely-spaced lights on the cable that flash in sequence.
- The robot keeps the cable tight as the lights unwind. Perhaps it needs to
install spring-loaded braces every now and then to accomplish this.
- A video camera on the robot can observe the lights it leaves behind.
- By tracking the amount of unwound cable, the robot can determine its
distance from every light it can see behind it.
- Accellerometers and gyrosopes on the robot can keep track of its
orientation.
- Using the video from the camera and knowledge of its orientation, the
robot can always determine it's XYZ position relative to the farthest light
it can see.
- By tracking its motion relative to the lights it leaves behind, it can
track it's absolute XYZ position in the pipe system.
The advantage of this system is that the robot will often be able to see a
light that is pretty far away, and make an absolute reading of its position
relative to that. This reduces the accumulation of small measurement errors
that you might get with other systems that only track motion incrementally.
--
Matt
| 
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML site map
> But... suppose you want to build a tethered (remotely powered)
> tunnel crawler to explore and map complex networks of metal piping,
> such as sewers, conduits, and ventilation ducts? Odometry would be a
> bit "sloppy" (especially in sewer pipes), and one couldn't depend on
> light or sound.