Pitot Tube Capacitance Sensing for Foreign Object Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pitot tube sensing apparatuses are prone to blockages by foreign objects such as ice, dust, and debris, leading to erroneous pressure measurements, which is critical for aircraft airspeed determination.
Innovation Solution
A pitot tube sensing apparatus with a capacitor comprising electrodes on opposing sides of the channel to measure capacitance, allowing detection of foreign objects and generating an alert, and calculating fluid speed based on pressure sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a pitot tube is used to measure pressure for determining fluid flow speed, then the measurement capability is provided, but the channel can be blocked by foreign objects leading to erroneous measurements
Solution Approach 1:
A capacitor is introduced as an intermediary sensing element between the pitot tube channel and the measurement system. The capacitor detects changes in capacitance caused by foreign objects (ice, dust, debris) entering the channel, providing an intermediate warning signal before the foreign object blocks the pressure measurement channel, thus preventing erroneous measurements
Solution Approach 2:
The capacitor provides preliminary detection of foreign objects before they can block the pitot tube channel. By detecting the presence of foreign objects in advance through capacitance changes, the system can take preventive action (such as generating alerts or activating heating elements) before the actual pressure measurement is compromised
2Reliability
If foreign objects block the pitot tube channel, then pressure measurement is compromised, but adding detection mechanisms increases device complexity
Solution Approach 1:
The capacitor serves multiple functions: it acts as part of the electrical circuit for pressure sensing while simultaneously functioning as a foreign object detection sensor. This multi-functionality allows foreign object detection without adding separate dedicated detection hardware, thereby minimizing the increase in device complexity
Solution Approach 2:
The foreign object detection function is merged with the existing electrical components of the pitot tube system. The capacitor that is already present in the pressure sensing circuit is utilized for dual purposes: maintaining electrical connectivity for pressure measurement and detecting foreign objects through capacitance changes, thus combining multiple functions into a single component
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
Enhances the reliability of fluid speed measurements by accurately detecting and preventing blockages, ensuring precise airspeed calculations for aircraft.
Implementation Method 1
a capacitor comprising two electrodes on opposing sides of the channel, wherein the two electrodes conform to the shape of an inner surface of the channel; and a system configured to: measure a parameter indicative of a capacitance between the two electrodes
Data Source
AI summary
A pitot tube sensing apparatus and method are disclosed for determining the presence or absence of a foreign object within the pitot tube sensing apparatus, and including a pitot tube having a channel, a pressure sensor coupled to the channel, a capacitor and a system. The capacitor includes two electrodes on opposing sides of the channel. The system measures a parameter indicative of a capacitance between the two electrodes and determines the presence or absence of a foreign object within the channel based on the parameter.