In general, markers used to measure position visually are called fiducial markers.
Some applications have a single type of fiducial (a solid circle or a cross) repeated many times.
Some applications independently positition many unique barcode-like fiducial markers, sometimes called fiducial targets, frame markers, augmented reality marker, etc.,
such as ...
The robot is called Alter. It is part of the robot exhibit at the Miraikan museum in Tokio. It seems from this website, that it has been created by Ikegami Takashi, specially for the exhibit, in order to explore human interaction by mimicking human poses.
The original T-slot frame system, was developed in the 80's by item GmbH and was quickly developed into the MB Building Kit System, hence I've always known it as item bar.
Since then though, there have been many other manufacturers producing similar systems. Examples include Bosch Rexroth (as mentioned by Guy Sirton), 80/20 (Andrew Capodieci's suggestion), ...
The general term is "feature detection". But this is very broad. It basically means to find anything in an image that fits to some description. A feature could be a line, point, blob, etc. A detector would be able to tell you the position of a feature in an image.
This is where computer vision ends and photogrammetry begins.
In order to make a connection ...
It sounds like you're describing a linear actuator with a pressure sensor (or strain gauge) attached to the end.
To bridge that system across bluetooth, you may want to check out one of several microcontrollers -- look for bluetooth modules, a motor (or servo) controller, and analog inputs (to read the strain gauge).
"A car with n trailers" is known to be a differentially flat system. Flatness implies that the Lie algebra generated by the system's vector fields (f and g_i's) is full. Therefore, the example you give is controllable.
In the example, f is zero, but you have two vector fields g1 and g2 that are associated with u1, u2, respectively. You need to work on the ...
USB is more than just a connector. It is a standard communications protocol, voltage levels, and even wiring colors.
I suggest you get a standard USB cable, cut it in half, then splice in your wires. http://wikipedia.org/wiki/USB does a good job of describing the pin outs on the various USB connectors.
This looks to me like a linear pneumatic actuator.
Pneumatic cylinders can be very fast acting, depending on the air pressure on hand, but they can be hard to control at any position other than their end stops, so they are usually used to switch between a limited number of fixed positions. Although the actuators themselves can be small, they require ...
A Google Image search on L293D board suggests that this is a widely available board manufactured by (or at least designed by) Deek-Robot.
The 5 pin connector mostly duplicates pins on the 6 pin green terminal block:
I suspect it is mostly useful for a quick motor connection when testing, whereas the green connector is used for a final motor connection.
You are not the first person in the world that wants to calibrate a larger robot, so there are commercially available solutions :)
The tool of choice in your case is a laser tracker. You attach one or multiple targets (laser reflectors) to your machine. The laser tracker consists of a laser that measures the distance to a target, two motors to pan and tilt ...
The idea is very interesting, and I wish you good luck implementing it.
However, it is not (very) simple to implement. Some reasons:
GPS is not at all accurate;
smartphones usually have a positioning error of +- 10 meters (30 feet). Unless your boats are actually some transatlantic beasts, this error is unacceptable;
GPS receivers with (very) high ...