Tethered UAV Localization Using Tether Angle and Length Sensing

The patent introduces an intermediary tether system with sensors as a mediator between the UAV and ground station. This tether-based measurement system acts as an intermediate localization method that does not rely on GPS signals, thereby resolving the contradiction by providing reliable localization through a different physical mechanism (tether length and angle measurements) when GPS is unavailable or interfered with.

The patent replaces optical/electromagnetic sensing methods (visual sensors, wireless communication-based localization) with a mechanical measurement system. The tether-based system uses physical measurements of tether length and angle, combined with inertial sensors, to determine relative position. This mechanical substitution eliminates the interference and obstruction problems inherent in optical and wireless methods, thereby improving measurement precision while maintaining system adaptability.

The patent replaces complex optical detection systems (cameras, optical sensors requiring extensive image processing) with a simpler mechanical-inertial measurement system. By using tether length measurements, angle sensors, and inertial measurement units (IMUs), the system achieves detection capability without the high computational burden of processing optical data, thereby reducing device complexity and onboard computing requirements.

The patent makes the tether serve multiple functions simultaneously: it provides mechanical connection for power and data transmission, acts as a measurement tool for localization through length and angle sensors, and serves as a structural element defining the system's dynamic envelope. This multi-functionality reduces overall system complexity by eliminating separate components for each function, thereby improving reliability without proportionally increasing device complexity.