UAV Position Measurement Using Retro-Reflector Tracking Without GPS
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Solution Overview
Problem
Unmanned aerial vehicles (UAVs) cannot perform remote control or measurement in environments where radio waves from artificial satellites are blocked, such as under bridges or near buildings, due to GPS signal loss, limiting their operational range and measurement capabilities.
Innovation Solution
A measuring system comprising a UAV equipped with a GPS device, a position measuring device capable of distance and angle measurement, and a ground base station for wireless communication, which uses retro-reflectors and control units to convert positional coordinates into GPS coordinates, enabling autonomous flight and measurement even in GPS-denied areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS device is used for positional measurement of UAV, then positional measurement can be performed in open areas, but positional measurement cannot be performed in GPS-denied areas such as under bridges or near buildings
Solution Approach 1:
A retro-reflector is introduced as an intermediary object attached to the UAV, which works with a ground-based laser range finder to enable positional measurement. The retro-reflector returns laser beams to the range finder, allowing the ground station to calculate UAV position without relying on GPS satellites, thus enabling operation in GPS-denied areas.
Solution Approach 2:
The patent replaces the electromagnetic wave-based GPS system with an optical laser-based measurement system. The ground-based laser range finder uses laser beams to measure distance to the retro-reflector on the UAV, substituting the satellite-based radio wave system with a ground-based optical system that works in GPS-denied environments.
2Ease of operation
If remote control is implemented for UAV operation, then UAV can be controlled from ground station, but control cannot be exercised in areas with radio wave blockage
Solution Approach 1:
The system implements feedback by continuously measuring the UAV's position using the laser range finder and retro-reflector, then transmitting this positional information back to the ground station. This feedback loop enables the ground controller to monitor and adjust UAV position even in areas where traditional radio control would fail, as the optical measurement system is not blocked by structures.
3Measurement precision
If measurement devices are installed on UAV, then measurement can be performed in accessible areas, but measurement cannot be performed in restricted areas where UAV cannot enter
Solution Approach 1:
The patent transitions from ground-based measurement (horizontal dimension) to aerial measurement (vertical/three-dimensional space). By launching the UAV into the air, the system can measure objects from above, reaching areas that are inaccessible to ground-based measurement devices, such as the interior of large structures or elevated positions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables remote control and measurement of UAVs in environments where GPS signals are unavailable, allowing for photogrammetry and shape measurement of complex or large objects without relying on satellite signals, thus expanding operational flexibility.
Implementation Method 1
the flying vehicle system has a retro-reflector as an object to be measured and the position measuring device is constructed so as to track the retro-reflector and perform distance measurement and angle measurement
Data Source
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AI summary
The invention provides a measuring system comprising a remotely controllable flying vehicle system with a GPS device and a measuring device installed thereon, a position measuring device installed at an arbitrary position and able to measure distance and angle and to track, a ground base station for controlling a flight of a flying vehicle, a remote controller able to give and take data to and from the ground base station and able to perform wireless communication to and from the flying vehicle system, and a control unit provided on the flying vehicle system or the ground base station, wherein the flying vehicle system has a retro-reflector as an object to be measured and the position measuring device is constructed so as to track the retro-reflector and perform distance measurement and angle measurement, wherein the flying vehicle system obtains GPS coordinates by the GPS device at least at two points during flight, the position measuring device measures positions of the two points of the flying vehicle system from an installation point, wherein the position measuring device measures positions of the flying vehicle system at the two points from the installation points, and either one of the control units are configured so as to obtain an absolute coordinate or GPS coordinate of the installation point of the position measuring device based on the GPS coordinates of the two points and based on distance measurement results and on angle measurement results by the position measuring device.