Optical Icing Sensor Droplet Size Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical sensors for detecting icing conditions in aircraft struggle to accurately determine droplet size in clouds using short pulse width lasers, which require high-speed, sensitive electronics and are not cost-effective.
Innovation Solution
An optical icing conditions sensor that uses a receiver array to measure light intensity over a range of angles, determining the median volumetric diameter of water droplets by identifying the scattering intensity peak and its breadth, allowing for the estimation of droplet size using low-cost lasers and photodetectors with low-speed digital electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If short pulse width lasers are used to detect cloud reflection signals, then droplet size measurement precision is improved, but device complexity and cost increase due to requirement of high-speed, sensitive electronics
Solution Approach 1:
The patent changes the temporal parameter of the laser pulse from short duration to long duration (continuous wave or extended pulse). This parameter change allows the use of simpler, lower-cost electronics while maintaining droplet size measurement capability through angular scattering distribution analysis rather than temporal signal resolution
Solution Approach 2:
The patent replaces the electronic detection system (high-speed electronics) with an optical detection approach using a receiver array that measures light intensity at multiple angles. This substitution eliminates the need for complex high-speed electronics while preserving measurement precision through spatial distribution analysis
2Measurement precision
If short pulse width lasers are used for droplet size detection, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent modifies the laser pulse duration parameter from short to long, which directly reduces component costs. Standard, lower-cost photodetectors and electronics can be used with continuous or extended pulse lasers, eliminating the need for expensive high-speed components while maintaining measurement accuracy through angular scattering analysis
Solution Approach 2:
The patent employs inexpensive, standard electronic components and photodetectors that can be mass-produced at low cost. By using long pulse width lasers and angular distribution measurement rather than temporal resolution, the system achieves droplet size measurement capability with commodity-grade components rather than specialized high-speed equipment
3Measurement precision
If receiver array measures light intensity over range of angles, then droplet size estimation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent divides the detection function into multiple discrete receivers positioned at different angles. Each receiver independently measures light intensity at its specific angle, and the collective angular distribution data is processed to determine droplet size. This segmentation approach achieves measurement accuracy without requiring a single complex high-speed detector
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
Enables accurate droplet size estimation within clouds, allowing for tailored safety procedures and reducing the need for expensive, high-speed electronics, while being cost-effective and efficient in detecting icing conditions.
Implementation Method 1
water droplets in clouds will scatter a portion of the light beam emitted by the transmitter
Implementation Method 2
the receiver array can be used to measure the intensity of scattered light at different angles
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method of operating an optical icing conditions sensor includes transmitting (402), with a transmitter, a light beam and thereby illuminating an illumination volume. A receiver array receives (404) light over a range of receiving angles. The receiver array is configured to receive light having the wavelength over a receiver array field of view which overlaps with the illumination volume. A controller measures (406) an intensity of light received by the receiver array. The controller determines (410) that a cloud is present if the intensity is greater than a threshold value. The controller calculates (412) scattering profile data of the light received by the receiver array if a cloud is determined to be present, which includes an angle of a scattering intensity peak within the range of receiving angles and a breadth of the scattering intensity peak. The controller (414) estimates a representative droplet size within the cloud using the scattering profile data.