Hand-Operated Sensor Adaptive Threshold for Subgrade Object Detection
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Solution Overview
Problem
Hand-operated sensors used for detecting objects embedded in building structure subgrades face challenges in reliably differentiating between actual object detection and over-detection due to uncontrollable signal weakening from subgrade influences, leading to inaccurate object localization and increased over-detection rates.
Innovation Solution
Equipping hand-operated sensors with a motion sensor device that records changes in direction and acceleration to adapt detection thresholds, utilizing biaxial acceleration sensors and a gyroscope to estimate speed and direction reversals, and incorporating an optical two-dimensional correlator for precise path recording and visualization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a constant scanning threshold is used for object detection, then the detection process is simple, but the sensor cannot reliably differentiate between actual object detection and over-detection due to uncontrollable signal weakening from subgrade influences
Solution Approach 1:
The patent applies dynamics by transitioning from a constant detection threshold to a variable detection threshold that automatically adapts based on the signal maximum detected during scanning. The detection threshold is dynamically adjusted according to the actual signal characteristics, allowing the sensor to reliably differentiate between actual objects and false signals while maintaining simplicity in operation.
2Reliability
If the sensor scans the entire surface area to set detection threshold, then the detection threshold can be reliably set, but the scanning time increases and productivity decreases
Solution Approach 1:
The patent applies preliminary action by performing a preliminary scan to establish the detection threshold before actual object detection. The sensor first scans the surface area to identify signal maxima and set the detection threshold, then uses this pre-established threshold for subsequent object detection. This separates the threshold setting function from the detection function, allowing for reliable threshold setting without continuously scanning the entire area during detection operations.
3Productivity
If a low detection threshold is set initially to detect all possible objects, then more objects can be detected, but false detections increase due to signal weakening from subgrade influences
Solution Approach 1:
The patent applies parameter changes by adjusting the detection threshold parameter based on the actual signal characteristics detected during scanning. Instead of using a fixed low threshold, the system dynamically modifies the threshold parameter according to the maximum signal strength observed, thereby adapting to varying subgrade conditions and signal strengths to minimize false detections while maintaining detection coverage.
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
This approach reduces over-detection rates and enhances the reliability of object detection by accurately differentiating between scanning and reversing motions, improving precision in determining object dimensions and locations within the subgrade.
Implementation Method 1
the acceleration of the hand-operated sensor is recorded in at least two directions with respect to an embedded object
Implementation Method 2
utilizing biaxial acceleration sensors and a gyroscope to estimate speed and direction reversals
Implementation Method 3
incorporating an optical two-dimensional correlator for precise path recording and visualization
Data Source
AI summary
A method for the detection of objects embedded in building structure subgrades such as cable, concrete reinforcing bars, conduit pipe and the like as well as a hand-operated sensor with an adaptive detection threshold operating according to the method, is disclosed. To reduce an over-detection with the adaptation of the detection threshold, a change in the direction of movement of the sensor being guided over the surface area is recorded with respect to an embedded object. The determination of a change in the direction of movement preferably takes place by measuring the sensor acceleration in two directions with respect to the embedded object. Corresponding speeds are computed at least as estimates from the acceleration values in order to generate a conclusion about a reversal of the direction of movement.