Optical Sensor Discharge Probability Calculation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light detection systems using optical sensors face issues with erroneous detection due to irregular discharges caused by noise components, which are not distinguished from regular discharges, leading to incorrect flame detection and sensor life determination.
Innovation Solution
A light detection system that includes an optical sensor, a second light source with known light quantity, and a control mechanism to calculate discharge probabilities and received light quantities by differentiating between regular and irregular discharges using stored sensitivity parameters and varying pulse widths of drive pulse voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a photoelectric tube type ultraviolet sensor is used to detect flame, then the sensor can detect light emitted from the flame, but irregular discharge phenomenon (pseudo discharge) caused by noise components occurs leading to erroneous detection
Solution Approach 1:
The patent segments the total discharge count into two distinct components: regular discharge (caused by flame light) and irregular discharge (caused by noise). This is achieved by measuring discharge characteristics under different conditions (with and without second light source, different pulse widths) and calculating separate discharge probabilities for each component, allowing them to be distinguished and processed differently.
Solution Approach 2:
The patent introduces a second light source with known light quantity as an intermediary element. This second light source serves as a reference to help distinguish between regular and irregular discharges by providing a controlled light input that allows the system to calculate and subtract the noise component's contribution from the total discharge.
2Reliability
If discharge probability calculation is performed to eliminate erroneous detection, then detection accuracy improves, but the discharge probability of noise component needs to be known in advance which increases system complexity
Solution Approach 1:
The system performs self-calibration by automatically determining the discharge probability of the noise component through measurements taken during operation. The control portion calculates the irregular discharge probability by comparing discharge characteristics under different lighting conditions (with and without the second light source) and different pulse widths, eliminating the need for external calibration equipment or pre-known noise parameters.
Solution Approach 2:
The patent changes measurement parameters (pulse width of drive pulse voltage, presence/absence of second light source) to differentiate between regular and irregular discharges. By measuring discharge probability at multiple parameter settings and analyzing the differences, the system can extract the noise component's discharge probability without requiring it to be known in advance.
3Reliability
If a shutter mechanism is provided to block electromagnetic wave incident on optical sensor, then failure detection capability is provided, but there is no discriminating method for distinguishing between regular discharge and irregular discharge with the change in measurement sensitivity due to the life of the optical sensor
Solution Approach 1:
The patent employs dynamic measurement by varying the pulse width of the drive pulse voltage and the lighting conditions (using the second light source) to capture changes in discharge characteristics. This dynamic approach allows the system to track how discharge probabilities change with sensor aging while maintaining the ability to distinguish between regular and irregular discharges through comparative analysis.
Solution Approach 2:
The system uses feedback from multiple measurements (discharge counts under different conditions) to continuously calculate and update the regular and irregular discharge probabilities. This feedback mechanism allows the system to adapt to changes in sensor sensitivity over time while maintaining accurate discrimination between discharge types through ongoing comparative analysis.
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
Accurately determines the presence or absence of a flame and reduces erroneous sensor life determination by calculating discharge probabilities and received light quantities, effectively distinguishing between regular and irregular discharges.
Implementation Method 1
a discharge occurring due to a photoelectric effect of an optical sensor
Implementation Method 2
a current detecting portion configured to detect a discharge current of the optical sensor
Data Source
AI summary
For calculating an optical sensor's regular-discharge probability, a light detection system includes the optical sensor, an application voltage generating circuit for applying a drive pulse voltage to the optical sensor, a discharge determining portion for detecting the optical sensor's discharge, a first discharge probability calculating portion, a sensitivity parameter storing portion for storing the optical sensor's sensitivity parameters, and a second discharge probability calculating portion for calculating a discharge probability of the optical sensor's regular discharge. The first discharge probability calculating portion calculates a discharge probability in: a first state in which light from an additional light source having a known light quantity is incident on the optical sensor or the additional light source is turned off; and a second state in which the additional light source's turning-on/turning-off status is different from the first state, with the drive pulse voltage's pulse width being the same as the first state.