Multi-Rotor Drag-Coefficient Calibration With Least Squares
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods struggle to accurately calculate the drag coefficient of multi-rotor aerial vehicles due to complex aerodynamic characteristics, leading to unreliable precision and high computational costs.
Innovation Solution
Conduct flight tests at multiple set airspeeds in windless and windy environments, record flight control logs with airspeed, tilt angle, and acceleration, select measurement combinations, and use the least squares solution to calibrate the drag coefficient, applying it to a real-time airspeed estimation algorithm for verification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If theoretical models and computational fluid dynamics simulations are used to establish the drag coefficient, then the aerodynamic characteristics can be analyzed, but the model accuracy is limited and computational costs are high
Solution Approach 1:
The patent transforms the drag coefficient calibration from a complex computational problem into a parameter optimization problem by using least squares method. The drag coefficient function parameters are adjusted to minimize the difference between estimated airspeed and measured airspeed, achieving high accuracy without expensive computational fluid dynamics simulations
Solution Approach 2:
The patent replaces the mechanical/computational approach of computational fluid dynamics with a mathematical optimization approach. Instead of solving complex aerodynamic equations through computation, the system uses least squares optimization to fit drag coefficient parameters to flight test data, significantly reducing computational cost while maintaining accuracy
2Measurement precision
If flight tests are conducted to calibrate the drag coefficient, then the calibration accuracy can be improved, but the test complexity and time consumption increase
Solution Approach 1:
The patent uses a partial action approach by conducting flight tests at only a few discrete airspeed points rather than continuous measurement across the entire flight envelope. The least squares method then interpolates to determine the drag coefficient function parameters, reducing test time while maintaining calibration accuracy
Solution Approach 2:
The patent performs preliminary data processing by pre-selecting measurement combinations from flight control logs and pre-processing the flight test data before calibration. This preliminary organization of data accelerates the calibration process by reducing the computational burden during the actual least squares optimization
Data Source
AI summary
A method, device, and computer-readable storage medium for calibrating the drag coefficient of a multi-rotor aerial vehicle is disclosed. The method includes: conducting flight tests at multiple set airspeeds along a straight and level flight path in both windless and windy environments, and recording, by a flight control system, flight control logs based on a measurement sequence comprising airspeed, tilt angle, and acceleration during the flight tests; selecting corresponding measurement combinations for the acceleration, cruise, and deceleration phases in each flight control log; taking the least squares solution derived from a preset number of measurement combinations as the drag coefficient calibration result; and applying the drag coefficient calibration result to a preset real-time airspeed estimation algorithm to obtain the airspeed estimation result thereby verifying the accuracy of the drag coefficient calibration result and the estimation algorithm.