MEMS Hot-Wire Flow Sensor Layout for Omnidirectional UAV Wind Sensing
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Solution Overview
Problem
Unmanned aerial vehicles (UAVs) lack an active sensing capability to measure turbulence, gusts, or other unsteady aerodynamic phenomena due to limitations in available sensor technology, with conventional in situ anemometry techniques failing to deliver in harsh and dynamic multirotor environments.
Innovation Solution
A fast-response sensor system, known as MAST (MEMS Anemometry Sensing Tower), utilizing microelectromechanical (MEMS) hot-wire devices with polygonally- or polyhedronally-arranged microscale hotwires to determine wind vector direction and magnitude, incorporating a plurality of MEMS flow sensors, a chassis substrate, support substrates, and an instrument amplifier for real-time wind estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional in situ anemometry techniques are used, then the sensor structure is simple, but the measurement precision and reliability are insufficient for harsh UAV environments
Solution Approach 1:
The sensor system is segmented into multiple independent MEMS flow sensors (at least five) arranged in specific geometric patterns (pentagon, hexagon, or polyhedron configurations). Each sensor measures flow in a specific direction, and their combined data provides comprehensive omnidirectional wind vector measurement, resolving the contradiction between measurement precision and device complexity through modular segmentation.
Solution Approach 2:
The invention transitions from conventional single-dimension or planar sensor arrangements to three-dimensional polyhedral configurations. Support substrates are arranged in 3D geometric shapes with sensors facing different directions, enabling omnidirectional measurement capability and significantly improving wind vector measurement accuracy in harsh UAV environments.
2Adaptability or versatility
If multiple MEMS flow sensors are arranged in 3D geometric configurations, then the omnidirectional measurement capability is improved, but the device complexity increases
Solution Approach 1:
The support substrates serve multiple functions: they provide structural support for the sensors, define the geometric arrangement (pentagon, hexagon, or polyhedron), position sensors at precise orientations, and maintain fixed distances from the chassis substrate. This multi-functionality reduces overall device complexity while enabling omnidirectional measurement capability.
Solution Approach 2:
The sensor system is designed to dynamically adapt to different measurement requirements through its geometric configuration. The polyhedral arrangement allows the system to effectively sense wind vectors from any direction by selecting and processing signals from the appropriate subset of sensors, providing versatile omnidirectional capability without requiring a fixed complex structure for every possible measurement scenario.
3Speed
If fast-response MEMS hot-wire devices are used, then the response speed is improved, but the manufacturing precision requirements increase
Solution Approach 1:
The complex wire array alignment requirements are extracted and handled at the MEMS device fabrication stage, where precision manufacturing techniques can be applied. The support substrates and chassis substrate provide standardized mounting interfaces that simplify the integration process, separating the high-precision manufacturing requirements from the system assembly process.
Solution Approach 2:
The support substrates act as intermediaries between the MEMS flow sensors and the chassis substrate. They provide standardized mounting interfaces and precise positioning features that facilitate the integration of fast-response MEMS devices while managing manufacturing precision requirements through modular design and standardized connection protocols.
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 MAST system provides a solid-state, lightweight, and robust flow sensor capable of measuring wind vectors in two dimensions, achieving high accuracy and resolution for UAVs, with wind angle and magnitude predictions within 5° and 0.2 m/s average error, respectively, suitable for gust mitigation control.
Implementation Method 1
The plurality of MEMS flow sensors may operate as a hotwire anemometer
Implementation Method 2
The at least one wire array may be part of a Wheatstone bridge
Implementation Method 3
The at least one wire array may be part of a Wheatstone bridge
Implementation Method 4
The at least one wire array may include four wire arrays configured as legs of a Wheatstone bridge
Data Source
AI summary
Disclosed is a fast-response sensor system to measure a fluid vector in a plurality of dimensions. This system, known as ‘MAST’ (for MEMS Anemometry Sensing Tower), utilizes microelectromechanical (MEMS) hot-wire devices to produce a solid-state, lightweight, and robust flow sensor system suitable for, e.g., real-time wind estimation onboard a UAV. The MAST uses three through eighteen polygonally-arranged microscale flow sensors to determine the fluid's vector's direction and magnitude.