The
system mentioned is an interesting
bit of kit. The great thing about it is that it is 3D. However, as some of you
point out, it probably is a
bit too imprecise to actually guide machinery for the
stage at this
point. With some time, I'm sure they can increase the accuracy. At that
point, it will be worth a look.
Regarding wireless communication to control machiinery, at this
point it is a known quantity. Industry has been using it for several years and there are in fact safe wireless protocols. We (
Stage Technologies) have been using it for quite some time as well for wireless winches and wireless trucks just like you guys have been discussing. It does mean some thought must be given to managing wireless channels (it operates in the 5Ghz spectrum), but unless there is something REALLY poorly built that throws out a lot of interference, it works very well.
You can have a look at how
Stage Tech is doing it now on
Youtube.. We use a sensor designed for industrial machinery known as Automated Guided Vehicles, or AGVs. It is a rotary
laser that scans for reflectors that are in known positions and calculates X, Y, and theta from what it sees. In the video, the sensor is housed in the slot on the side of the truck. It is a very accurate 2D
system; however, the big drawback is it requires a
line of site to at least 3 reflectors which can easily be blocked. To get around this, we put in many reflectors (6" diameter cylinders with a special reflective
pattern on them). Usually, this requires a "discussion" with the
scenic designer. Also, we allow operating without reference to an absolute position (ded reckoning) for a certain amount of time.
There is a lot of merit in having
stage hands push things to
spike marks. It is simple and (hopefully reliable). I will say though that it is REALLY cool to see scenery
shift around seamlessly as if by magic. Sometimes you may need to move a
wagon that is too large to be manually moved safely or accurately. It also may be more cost-effective in the long-term to eliminate the labor cost. Or, perhaps, someone in charge just wants to have the technological spectacle.
Just like any technology, it is always a worthwhile discussion to have whether or not the benefits outweigh the costs. Fortunately, very soon you will be able to judge for yourself! Trucks just like these are coming soon to a city near you. ;-)