Proximity Detector False Positive Reduction via State-Change Testing
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Solution Overview
Problem
Conventional proximity detection systems using RF or IR signals are prone to false positives due to interference from extraneous signals, leading to unreliable object detection in noisy environments.
Innovation Solution
A system that employs a transmitter and receiver with a controller to perform state-change and same-state tests, establishing a range of values around measurement signals to differentiate between actual object reflections and extraneous signals, thereby minimizing false detections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional proximity detection systems use RF or IR transmitters and receivers to detect objects, then object detection capability is provided, but false-positive readings occur due to interference from extraneous signals
Solution Approach 1:
The transmitter operates in periodic cycles, alternating between emitting detection signals and remaining inactive. This periodic operation allows the system to compare measurements taken during active transmission with measurements taken during inactive periods, enabling differentiation between genuine reflected signals and continuous extraneous interference
Solution Approach 2:
The system implements feedback by comparing measurement values obtained during transmitter on-states with measurement values from off-states. The controller analyzes these feedback measurements to determine whether detected signals represent actual objects or extraneous interference, thereby improving detection reliability
Solution Approach 3:
The system performs preliminary measurements during the transmitter off-state to establish baseline measurement values before actual detection begins. These preliminary measurements allow the system to pre-characterize the interference environment and use this information to filter false positives during subsequent detection cycles
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 effectively reduces false positives by confirming the presence of an object through a series of tests, ensuring accurate detection even in noisy conditions.
Implementation Method 1
a transmitter operable to switch between on and off states to respectively activate and deactivate emanation of a detection signal from the transmitter along a path
Implementation Method 2
a receiver positioned to receive a reflection of the detection signal from off the object when situated proximate the transmitter in the path of the detection signal
Data Source
AI summary
In a reflection type proximity detector or method, a controller calculates a calibration value based on ambient conditions with the transmitter off and then performs tests. In each test, the calibration value is added to and subtracted from a measured value taken with the transmitter in one state (on or off) and a second measured value is then taken and compared with this range. In tests where the transmitter is switched from off to on between the measurements and the second value exceeds the range, and tests where the transmitter is switched from on to off between the measurements and the second value is below the range, an object is detected. When the transmitter does not switch states between the measurements, and the second value is less than or greater than the range, then no object is detected, as the change in measured value likely resulted from an outside signal.