Airframe-Embedded Ultrasonic Anemometers for Hover Airspeed Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for determining air velocities around aerial vehicles, particularly at low speeds or in hovering flight modes, are inadequate due to the limitations of Pitot tubes, which are less effective and not commonly used for such operations.
Innovation Solution
The integration of ultrasonic anemometers with multiple transducers on the aerial vehicle's airframe, which transmit and receive acoustic signals to determine air velocities by calculating differences in transit times, allowing for precise control and navigation in various flight conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Pitot tubes are used to determine air speeds, then air speed measurement is effective at high speeds, but measurement precision deteriorates at low speeds and hovering flight modes
Solution Approach 1:
The patent replaces the mechanical Pitot tube system with an ultrasonic anemometer system that uses acoustic waves to measure air velocity. The ultrasonic transducers emit and receive acoustic signals, and the system calculates air speed based on the time difference of flight of the acoustic signals in opposite directions, eliminating the mechanical limitations of Pitot tubes at low speeds
Solution Approach 2:
The patent changes the measurement parameter from pressure differential (Pitot tube method) to acoustic signal time of flight (ultrasonic method). This parameter change enables accurate measurement across the full range of flight speeds including hovering, where pressure differential methods fail
2Measurement precision
If multiple ultrasonic transducers are integrated on the airframe, then measurement precision and adaptability improve, but device complexity increases
Solution Approach 1:
The ultrasonic transducers are designed to serve multiple functions: they act as both transmitters and receivers of acoustic signals, and the same hardware configuration can measure air velocity in multiple directions by strategically placing transducers on different surfaces of the airframe. This multi-functionality reduces the need for separate measurement systems for different flight conditions
Solution Approach 2:
The patent transitions from one-dimensional linear transducer arrangements to three-dimensional spatial distribution of transducers on the airframe surfaces. This spatial arrangement enables measurement of air velocity vectors in multiple directions simultaneously, providing comprehensive wind data for complex flight maneuvers
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 determination of air velocities and directions, enhancing the stability and control of aerial vehicles during low-speed operations and hovering modes by providing real-time wind data for adjusting thrust, drag, weight, and lift forces.
Implementation Method 1
transmit and receive acoustic signals to determine air velocities by calculating differences in transit times
Implementation Method 2
calculate differences in transit times
Data Source
AI summary
Aerial vehicles may be outfitted with one or more ultrasonic anemometers, each having ultrasonic transducers embedded into external surfaces. The transducers may be aligned and configured to transmit acoustic signals to one another, and receive acoustic signals from one another, along one or more paths or axes. Elapsed times of signals transmitted and received by pairs of transducers may be used to determine air speeds along the paths or axes. Where two or more pairs of transducers are provided, a net vector may be derived based on air speeds determined along the paths or axes between the pairs of the transducers, and used to generate control signals for maintaining the aerial vehicle on a desired course, at a desired speed or altitude, or in a desired orientation. The transducers may be dedicated for use in an anemometer, or may serve multiple purposes, and may be reoriented or reconfigured as necessary.