Variable-Polarization GPR for UAV Dam Defect Detection
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Solution Overview
Problem
Existing ground penetrating radar systems for dam hidden danger detection are limited by their single polarization mode, which makes it difficult to distinguish electromagnetic wave signals from hidden dangers of different shapes and orientations, and require complex detection processes and large antenna arrays, making them inefficient and inconvenient for use in complex terrains.
Innovation Solution
An unmanned airborne ground penetrating radar system utilizing a variable polarization ground penetrating radar with orthogonal dual-polarization Vivaldi antenna arrays and a forward-looking laser rangefinder, allowing for omni-directional and high-precision detection by controlling the angle of the radar antenna array to maintain a constant distance from the ground, enhancing antenna gain and detection depth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single polarization mode is used in ground penetrating radar, then the device complexity is reduced, but the measurement precision and detection capability for hidden dangers of different shapes and orientations deteriorate
Solution Approach 1:
The patent employs a variable polarization antenna that can dynamically adjust its polarization state (horizontal, vertical, circular, or elliptical) based on detection needs. This dynamic polarization switching capability allows a single antenna to replace multiple fixed-polarization antennas, reducing device complexity while maintaining high measurement precision for detecting hidden dangers with different shapes and orientations.
Solution Approach 2:
The invention changes the polarization parameter of the electromagnetic wave by using a variable polarization antenna. By adjusting the polarization state parameter, the radar can adaptively detect hidden dangers with different orientations and shapes, improving measurement precision without requiring multiple antennas with different fixed polarizations, thus avoiding increased device complexity.
2Measurement precision
If a fully-polarized antenna array with multiple polarization directions is used, then the detection capability for various hidden dangers is improved, but the device complexity and detection process complexity increase due to time-sharing detection requirements
Solution Approach 1:
The patent uses a single variable polarization antenna that can perform multiple polarization detection functions (horizontal, vertical, circular, elliptical) sequentially. This multi-functional antenna replaces the need for multiple specialized antennas, achieving comprehensive detection capability while significantly reducing antenna array complexity and eliminating the need for complex time-sharing switching systems.
3Volume of moving object
If a small-volume circularly polarized helical antenna is used for UAV transmission, then the antenna size is reduced for UAV suitability, but the antenna performance and bandwidth deteriorate due to mismatch with linear polarized broadband receiving antennas
Solution Approach 1:
The patent employs a variable polarization antenna that can change its radiation characteristics to match the receiving antenna's polarization state. By dynamically adjusting the polarization parameter, the system achieves consistent antenna performance and broadband operation without the mismatch problems that would occur with fixed circular or linear polarization antennas, while maintaining a compact size suitable for UAV deployment.
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
The system achieves refined and comprehensive detection of dam hidden dangers with improved antenna directivity and detection depth, enabling efficient and safe detection in complex terrains through adaptive control of the UAV's flight path and radar antenna orientation.
Implementation Method 1
orthogonal dual-polarization Vivaldi antenna transmitting subarrays and orthogonal dual-polarization Vivaldi antenna receiving subarrays
Implementation Method 2
forward-looking laser rangefinder, controlling the angle of the radar antenna array to maintain a constant distance from the ground
Implementation Method 3
polarization information is sensitive to the shape and distribution orientation of the target inside a measured structure. The hidden dangers in different positions, directions and shapes may be distinguished by collecting different polarization information
Data Source
AI summary
Disclosed are an unmanned airborne ground penetrating radar system and an inspection method for a dam hidden danger detection, including an unmanned aerial vehicle (UAV) system; the UAV system includes an unmanned aerial vehicle, a sensor platform, a radar platform, a forward-looking laser rangefinder and a ground penetrating radar; the sensor platform is installed on the UAV, and the forward-looking laser rangefinder is installed on the sensor platform, and the radar platform is installed on the UAV at one side of the sensor platform; moreover, the ground penetrating radar is installed on the radar platform, and a variable polarization ground penetrating radar antenna array is arranged in the ground penetrating radar; the variable polarization ground penetrating radar antenna array includes a substrate, and a plurality of groups of orthogonal dual-polarization Vivaldi antenna transmitting subarrays and receiving subarrays are mounted on the substrate.