Multi-UAV Aerial Photogrammetry Synchronization for Moving Object Measurement
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Solution Overview
Problem
Aerial photogrammetry faces challenges in maintaining measurement accuracy due to time differences and deviations in flight paths of UAVs, especially when capturing images of moving objects or agricultural products, which can result in decreased relative orientation accuracy and failure to achieve synchronized photography.
Innovation Solution
An aerial photogrammetric method and system that synchronize the flight of multiple UAVs using a base control device, ensuring simultaneous image capture without considering individual vehicle differences, thereby maintaining high measurement accuracy and enabling the creation of 3D models across a wide field angle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the time difference between images acquired at two points is decreased to photograph moving objects simultaneously, then measurement accuracy is improved, but the base line length is shortened which decreases measurement accuracy
Solution Approach 1:
The patent divides the measurement task into multiple independent image acquisition operations performed by multiple UAVs. Each UAV captures images at its own timing and position, and the system processes these segmented measurements collectively to achieve accurate 3D reconstruction without requiring synchronized long-baseline photography.
Solution Approach 2:
The patent changes the measurement parameters by allowing different acquisition times (atim1, atim2) for different UAVs and using time-stamped image data. The system processes images with time differences by incorporating temporal information into the photogrammetric calculation, enabling accurate measurement even when base line length is short or objects are moving.
2Measurement precision
If multiple UAVs are used to increase base line length and improve measurement accuracy, then measurement accuracy is improved, but flight path deviations cause time synchronization problems
Solution Approach 1:
The patent implements a feedback mechanism where the base control device receives position information (lat1, lon1, alt1, atim1) and image data from multiple UAVs, then processes this feedback information to perform photogrammetric calculations. The system uses the actual flight paths and timing data returned from each UAV to compute accurate 3D coordinates, compensating for any flight deviations without requiring pre-synchronized timing.
Solution Approach 2:
The patent adopts a dynamic approach where each UAV operates independently with its own flight path and timing, rather than requiring rigid synchronization. The system dynamically processes the varying acquisition times and positions from multiple UAVs, allowing flexible operation while maintaining measurement accuracy through adaptive photogrammetric computation.
3Loss of information
If photographs are taken at low altitude to observe agricultural products in detail, then observation quality is improved, but conditional changes over time such as leaf movements become conspicuous
Solution Approach 1:
The patent segments the image acquisition process across multiple UAVs that capture images at different times (atim1, atim2) and positions. By dividing the measurement task among multiple independent acquisition operations, the system can process images with time differences without requiring the object to remain completely stationary, thereby maintaining detailed observation quality while accommodating natural object movements.
Data Source
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AI summary
The invention provides an aerial photogrammetry by using two or more of flying vehicles each equipped with a GPS device and an image pickup unit, comprising a step of setting up two or more photographing points and of setting up a photographing point area respectively with each of the photographing points as the center, a step of measuring a position of the flying vehicle by said GPS device, a step where each of the flying vehicle reaches each corresponding photographing point area and maintains the position of the photographing point area, a step of acquiring a time when the flying vehicle finally reaches the photographing point area, a step of setting up a shutter timing time after a predetermined time from the moment when the flying vehicle has finally reached the photographing point area, and a step of taking aerial photographs by the two or more flying vehicles at the shutter timing time.