Optical Pulse Coincidence Detection for Low False Triggers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Highly sensitive optoelectric receiving elements in optical pulse propagation time measurement methods, such as laser distance measurement, are prone to interference pulses from background noise and spontaneous quantum mechanical effects, leading to false triggers and reduced detection reliability.
Innovation Solution
A device and method that divide the optical signal between at least two receiving elements and compare the resulting electrical signals to identify and suppress interference pulses, ensuring only coincident pulses within specified tolerances are recognized as real, allowing for higher sensitivity without increased false trigger rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If highly sensitive optoelectric receiving elements are used to detect small optical pulses, then detection sensitivity is improved, but false trigger rate increases due to interference pulses from background noise and quantum mechanical effects
Solution Approach 1:
The optical signal is divided and fed to multiple receiving elements (at least two) in parallel. Each receiving element processes the signal independently, and their outputs are logically combined. This segmentation allows the system to maintain high sensitivity while reducing false triggers, since interference pulses are random and unlikely to occur simultaneously in multiple channels.
Solution Approach 2:
The electrical signals from multiple receiving elements are combined through logical operations (such as AND logic) to produce a final detection output. Only when corresponding pulses are detected in multiple channels simultaneously is a valid signal registered. This merging approach consolidates the sensitivity benefits of multiple high-sensitivity elements while suppressing random interference.
2Reliability
If spatial, spectral and temporal filtering are applied to reduce interference pulses, then false trigger rate is reduced, but detection capability for weak signals is compromised
Solution Approach 1:
Instead of applying static filtering that permanently reduces signal strength, the system uses dynamic coincidence detection where the decision to accept a signal is made in real-time based on temporal correlation between multiple channels. This dynamic approach maintains full signal strength while achieving interference rejection through temporal selectivity.
Solution Approach 2:
The system uses the statistical properties of random interference (that it does not occur simultaneously in multiple independent channels) to automatically reject false triggers without external filtering. The multiple receiving elements serve themselves by providing mutual verification, eliminating the need for filtering that would compromise weak signal detection.
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 enables the effective utilization of highly sensitive receiving elements with reduced interference pulse rates, enhancing detection reliability and accuracy in optical pulse measurement applications.
Implementation Method 1
each containing an optoelectronic receiving element for converting a component into an electrical signal
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
Device and method for detecting an optical pulse (I) in an optical signal (x), with at least two parallel receiving channels (U, V), each receiving a portion (x1, x2) of the optical signal (x) and each containing an optoelectronic receiving element (3, 4) for converting the portion (x1, x2) into an electrical signal (u, v) in which an optical pulse (I) is represented as an electrical pulse (Eu, Ev), wherein an optical pulse (I) is detected when an electrical pulse (Eu, Ev) occurs simultaneously in at least two electrical signals (u, v) - compensated for any signal propagation time differences (Δt) between the receiving channels (U, V) - within predetermined tolerance limits (σ).