Omnidirectional Airspeed Measurement for Low-Speed Flight Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing airspeed measurement systems are unsuitable for low-speed flight vehicles like multicopters, as they are not designed for omnidirectional measurement and are less sensitive at low speeds, making it difficult to accurately estimate flight times and detect changes in wind speed.
Innovation Solution
A 2-axis thermal flow sensor system that measures airspeed along orthogonal axes in the horizontal direction, combined with a 1-axis flow sensor for vertical measurement, along with additional sensors for temperature, pressure, and geomagnetic data, to provide accurate and omnidirectional airspeed measurement, reducing the influence of airflow from rotary wings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional airspeed indicators (pitot tubes) are used, then unidirectional airspeed measurement is achieved, but omnidirectional measurement capability is lost
Solution Approach 1:
The airspeed measurement function is segmented into multiple independent 1-axis flow sensors, each measuring airspeed along a specific axis. By arranging three 1-axis sensors orthogonally (X, Y, Z axes), the system achieves omnidirectional measurement capability while maintaining relatively simple individual sensor structures.
Solution Approach 2:
The measurement capability is extended from one dimension (unidirectional pitot tube) to three dimensions by adding sensors along orthogonal axes. This dimensional expansion enables omnidirectional airspeed measurement, allowing the system to detect airflow from any direction in 3D space.
2Measurement precision
If conventional airspeed sensors are used, then measurement is possible, but sensitivity at low speeds is insufficient
Solution Approach 1:
The traditional mechanical pitot tube system is replaced with thermal flow sensors that use thermal conduction principles. These sensors heat a sensing element and measure the rate of heat loss to the surrounding air, which provides superior sensitivity at low speeds compared to mechanical pressure-based systems.
Solution Approach 2:
The measurement parameter is changed from pressure differential (pitot tube) to thermal conduction rate (thermal flow sensor). This parameter change enables the system to detect very low airspeeds by measuring the subtle thermal effects of slow airflow, significantly improving low-speed sensitivity.
3Measurement precision
If flight time estimation is performed without accurate airspeed data, then operation is simpler, but flight time estimation accuracy deteriorates
Solution Approach 1:
The orthogonal array of flow sensors serves multiple functions: it provides omnidirectional airspeed measurement, detects wind speed and direction, enables accurate flight time estimation, and supports various flight control functions. This multi-functionality justifies the increased sensor complexity by delivering comprehensive aerodynamic data from a single sensor arrangement.
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 efficient and accurate horizontal and vertical airspeed measurement, improving the estimation of flight times and enabling detection of abrupt changes like nosedives or updrafts, thus enhancing the control and balance of low-speed flight vehicles.
Implementation Method 1
a 2-axis thermal flow sensor including at least one heat source and two sets of temperature sensors that are arranged along the two axes orthogonal to each other
Data Source
AI summary
A technique enables horizontal measurement of the airspeed of a low-speed flight vehicle. An airspeed measurement system is for a low-speed flight vehicle, and includes a flow sensor that measures an airspeed along at least two axes in a horizontal direction during flight of the low-speed flight vehicle.