Optical Sensor Discharge Probability Calculation for Flame Detection
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Solution Overview
Problem
Existing light detection systems using optical sensors face issues with erroneous flame detection due to irregular discharges caused by noise components, which are not accurately distinguished from regular discharges, leading to incorrect sensor life determination and flame presence detection.
Innovation Solution
A light detection system that calculates discharge probabilities based on the number of pulse applications and discharges during different states of light shielding and pulse width variations, using a second light source with known light quantity to determine received light quantities and differentiate between regular and irregular discharges, thereby reducing erroneous detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a photoelectric tube type ultraviolet sensor is used to detect flame, then light detection capability is improved, but irregular discharge caused by noise component occurs leading to erroneous detection
Solution Approach 1:
The patent segments the detection process into multiple measurement cycles with different integration periods (first integration period and second integration period). By dividing the detection into separate measurement phases with different characteristics, the system can distinguish between regular flame discharges and irregular noise discharges, thereby maintaining high detection capability while improving reliability.
Solution Approach 2:
The patent changes the integration period parameter between different measurement cycles. The first integration period is set longer than the second integration period, creating measurable differences in discharge characteristics. This parameter variation allows the system to identify patterns that distinguish true flame signals from noise, resolving the contradiction between detection sensitivity and accuracy.
2Reliability
If discharge probability calculation is performed to eliminate erroneous detection, then detection accuracy is improved, but the discharge probability of noise component becomes unknown requiring additional measurements
Solution Approach 1:
The patent implements periodic action by performing repeated measurement cycles with alternating integration periods. Multiple consecutive measurements are taken with the first integration period, followed by measurements with the second integration period. This periodic alternation enables statistical calculation of discharge probabilities without requiring complex additional hardware or measurement systems.
Solution Approach 2:
The system uses its own measurement data from the optical sensor to self-determine the discharge probability of the noise component. By analyzing the discharge characteristics across multiple measurement cycles with different integration periods, the system calculates the noise discharge probability internally without needing external calibration sources or additional measurement devices, thus reducing overall system complexity.
3Measurement precision
If multiple measurement cycles with different integration periods are performed, then discharge probability of noise can be calculated, but measurement time increases
Solution Approach 1:
The patent applies partial action by performing a predetermined number of measurement cycles rather than continuous measurements. The system executes a specific count of first measurements and second measurements, which is sufficient to calculate discharge probability with adequate precision but limited to avoid excessive measurement time. This selective number of cycles balances precision requirements with time efficiency.
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 accurately determines the presence or absence of a flame and reduces the likelihood of incorrect sensor life determination by distinguishing between regular and irregular discharges, improving the reliability of light detection.
Implementation Method 1
an irregular discharge phenomenon (pseudo discharge) caused by a noise component other than a discharge occurring due to a photoelectric effect occurs in discharge of the photoelectric tube type ultraviolet sensor
Data Source
AI summary
To calculate a probability of an optical sensor's irregular discharge, a light detection system includes an optical sensor, an application voltage generating circuit that applies a drive pulse voltage to the optical sensor, a discharge determining portion that detects the optical sensor's discharge, a discharge probability calculating portion that calculates a discharge probability for each of first and second states in which the optical sensor is shielded from light and the drive pulse voltage's width in the second state is different from the first state, a sensitivity parameter storing portion storing the drive pulse voltage's reference pulse width as the optical sensor's sensitivity parameter, and another discharge probability calculating portion that calculates an irregular discharge's probability that occurs without depending on the optical sensor's received light quantity, based on the sensitivity parameter, and the discharge probabilities calculated and the drive pulse voltage's widths in the first and second states.