Deflection Calibration Apparatus for Laser High-Speed Pavement Testing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for pavement deflection testing, such as the Beckman beam method and drop hammer method, are not suitable for laser type high-speed deflection testers due to differences in load-loading modes and measurement principles, limiting the widespread adoption of new techniques in engineering fields due to metrological calibration challenges.
Innovation Solution
A deflection calibration apparatus and method using rotating discs with inclined surfaces and a driving system to simulate pavement deflection basins, allowing laser-Doppler vibrometers to measure deflection values, and calculating theoretical deflection values based on Euler-Bernoulli beam theory and two-parameter models to calibrate the laser type high-speed deflection testers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional methods (Beckman beam method, drop hammer method) are used for pavement deflection testing, then test procedures and calibration specifications can be established, but these methods are not suitable for laser type high-speed deflection testers due to different load-loading modes and measurement principles
Solution Approach 1:
The patent creates a calibration apparatus that copies the essential characteristics of pavement deflection using a controlled mechanical system. The apparatus includes a rigid support structure with a movable platform that can be displaced to simulate pavement deflection, allowing the laser type high-speed deflection tester to measure calibrated deflection values under controlled conditions that replicate real pavement testing scenarios.
Solution Approach 2:
The patent introduces a calibration apparatus as an intermediary between the laser type high-speed deflection tester and the pavement being tested. This intermediary device provides known reference deflection values through controlled mechanical displacement, enabling the tester to be calibrated without directly testing the pavement itself, thus resolving the adaptability issue while maintaining calibration reliability.
2Speed
If laser type high-speed deflection tester is used to measure pavement deflection at high speed, then detection speed and safety are improved, but the ability to perform metrological calibration is lost
Solution Approach 1:
The patent implements preliminary calibration action before the actual high-speed pavement testing. The calibration apparatus is used to establish reference deflection values and calibration factors in advance, under controlled conditions. This preliminary calibration ensures that the laser type high-speed deflection tester is properly calibrated before being used for rapid pavement detection, thereby maintaining measurement precision while enabling high-speed operation.
Solution Approach 2:
The patent employs a dynamic calibration system where the movable platform can be displaced at controlled speeds and distances to simulate various pavement deflection scenarios. The system includes sensors to measure the actual deflection and the corresponding laser measurements, allowing dynamic calibration that matches the operational conditions of high-speed pavement testing while ensuring metrological accuracy.
3Ease of manufacture
If new laser type high-speed deflection testing technique is adopted, then low detection cost and high safety are achieved, but widespread use is affected due to inability to perform metrological calibration and provenance
Solution Approach 1:
The patent enables the laser type high-speed deflection tester to perform self-calibration using the integrated calibration apparatus. The system automatically measures known deflection values from the calibration platform and computes calibration factors without requiring external calibration equipment or procedures. This self-service calibration capability maintains the low detection cost advantage while establishing reliable metrological provenance for the testing results.
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 non-destructive calibration and accurate simulation of deflection speeds and basins, breaking through previous calibration limitations and ensuring reproducibility and correlation with conventional measurement methods.
Implementation Method 1
measures a descent speed vm of the pavement under load using Laser-Doppler technique during high-speed travel
Data Source
AI summary
The disclosed are a deflection calibration apparatus and method for a laser type high-speed deflection tester. The apparatus comprises rigid supports, rotating discs, driving systems and a deflection calibration unit; the rotating discs are mounted on the rigid supports and driven by the driving systems to rotate, and upper surfaces of the rotating discs are processed into inclined planes having a slope in the circumferential direction; the deflection calibration unit is used for calibrating a laser type high-speed deflection tester according to measured and theoretical deflection values; laser emitted by a Laser-Doppler vibrometer is incident on the upper surfaces of the rotating discs to obtain the measured deflection value; the deflection calibration unit calculates the theoretical deflection value according to the inclination angle and the rotational angular velocity of each rotating disc and the distance between a laser incident point and the gyration center of each rotating disc.