Abstract: An optical rotary joint includes a first annular portion and a second annular portion configured to rotate with respect to each other. Optical receivers on a receiver face of the second annular portion receive from optical transmit beam launchers on an emitter face of the first annular portion. The transmit beam launchers transmit optical signals to the optical receivers as the second annular portion rotates with respect to the first annular portion.

Abstract: The invention is a method of coordinating the movement of a plurality of oppositely directed tramcars operating along a single guidelane. This includes positioning a plurality of fixed stop-boarding areas along the guidelane. By-pass lanes enabling oppositely moving tramcars to pass each other are located in association with at least some of the stop-boarding areas. A predetermined arrival time for each tramcar at each stop-boarding area is calculated such that oppositely moving pairs of tramcars approaching a common stop-boarding area will arrive at approximately the same time. A processor onboard each tramcar calculates the distance and time remaining to the next stop-boarding area. With a known time and distance remaining to the next stop-boarding area, each on-board processor adjusts the speed of the tramcar such that it arrives at approximately the predetermined arrival time.