Laser Sensor Height Discrimination for Burglar Alarm Misdetection
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Solution Overview
Problem
Burglarproof systems using laser sensors often misdetect small animals as humans, leading to reduced reliability due to the difficulty in distinguishing between human and animal heights, especially when obstructions are present, resulting in undetectable areas within the monitoring range.
Innovation Solution
A target detecting device that emits a laser beam diagonally downward, allowing for the determination of whether an object is a target or non-target based on distance information, with a scan mechanism to adjust the laser beam direction for a wide detecting range and two-dimensional coverage, and a software processing detection algorithm to differentiate between human and small animal heights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the laser sensor is installed horizontally at about the height of a waist of an adult to detect humans, then human detection accuracy is improved, but small animals may still be misdetected as humans
Solution Approach 1:
The patent introduces a vertical height dimension to the detection process by measuring the distance from the laser sensor to the detected object. This allows the system to differentiate between humans and small animals based on their height differences, resolving the contradiction between detecting humans accurately and avoiding false detection of small animals.
Solution Approach 2:
The patent changes the detection parameter from merely horizontal position detection to include vertical height measurement. By measuring the distance information in the vertical dimension and comparing it against predetermined height thresholds, the system achieves both high human detection accuracy and reliable differentiation from small animals.
2Area of stationary object
If the laser sensor is installed horizontally in a low position to avoid obstructions, then detection coverage is improved, but multiple undetectable areas occur in the guarding area
Solution Approach 1:
The patent employs vertical angle detection to add a height dimension to the monitoring coverage. By detecting objects at different vertical angles and distances, the system can overcome obstructions and eliminate blind spots that would exist in a purely horizontal detection plane, thus improving both coverage area and reliability.
Solution Approach 2:
The patent uses asymmetric detection by combining horizontal scanning with vertical angle measurement. The detection system does not rely on a single horizontal plane but incorporates vertical dimension asymmetry to detect objects at various heights and positions, thereby eliminating undetectable areas and improving overall detection reliability.
3Area of stationary object
If the laser beam is emitted diagonally downward to achieve wide detecting range, then detection range is improved, but height discrimination between humans and animals becomes more difficult
Solution Approach 1:
The patent implements feedback by continuously measuring the distance information from the laser sensor to detected objects and comparing this data against predetermined height thresholds. This feedback mechanism allows the system to maintain wide detection coverage while accurately discriminating between humans and animals based on their height differences, even when detecting diagonally downward.
Solution Approach 2:
The patent uses dynamic detection by continuously scanning and measuring distance information at various angles. The system dynamically adjusts its detection parameters and compares real-time distance measurements against stored height data, enabling both wide coverage and accurate height discrimination through adaptive processing.
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 solution effectively reduces misdetection while maintaining a wide detecting range by determining the height of objects using distance information and adjusting the laser beam direction, thereby improving the accuracy of human detection and reducing false alarms.
Implementation Method 1
The photodetector detects a reflection light reflected from the target. Flight time, that is, reflection time is computed to measure a distance from the laser sensor to the target.
Implementation Method 2
Flight time, that is, reflection time is computed to measure a distance from the laser sensor to the target.
Implementation Method 3
a laser emitting and receiving portion (2, 3) which can emit a laser beam (14) diagonally downward from an installing position
Data Source
AI summary
In a target detecting technique using a laser sensor, misdetection can be reduced while maintaining a wide detecting range. A target detecting method for detecting a target by emitting a laser beam diagonally downward from an installing position of a laser emitting and receiving portion. The method includes the steps of: obtaining distance information from the laser emitting and receiving portion to an object to be detected; determining, when the object to be detected approaches the laser emitting and receiving portion, whether the tracking of the object to be detected is stopped or not; and determining, when the tracking of the object to be detected is stopped, whether the object to be detected is the target or a non-target based on distance information immediately before the tracking of the object to be detected is stopped.