US Patent 10364026 Track and tether vehicle position estimation

A UAV tethering system provides an environment in which to fly an unmanned aerial vehicle (UAV) where the tether is selected to prevent the UAV from unintentional contact with the ground or other objects within the flight area. A tether may connect the UAV to a shuttle that slides along a track. The tether may be used to provide efficient, robust and accurate positioning information. The system can be configured to detect the angle at which the tethering line extends from the shuttle, the length of the extended tethering line, and then compute the position of the UAV relative to the shuttle. Furthermore, by knowing the position of the shuttle, the absolute position of the UAV can be determined.