Methods of three dimensional (3D) airflow sensing and analysis
Embodiments of methods and apparatus for close formation flight are provided herein. In some embodiments, a method of sensing three dimensional (3D) airflow by an aircraft includes: collecting measurements characterizing airflow near the aircraft; analyzing the collected measurements; creating, by a processor, a computer model predicting one or more 3D airflow patterns parameter values based on the analyzing; obtaining one or more additional measurements characterizing airflow near an aircraft of the plurality of aircraft, and evaluating an error between an airflow parameter value predicted by the computer model and the one or more additional measurement.
1. A method of sensing three dimensional (3D) airflow by an aircraft, comprising:
collecting measurements characterizing airflow near the aircraft;
analyzing the collected measurements;
creating, by a processor, a computer model predicting one or more 3D airflow pattern parameter values based on the analyzing;
obtaining one or more additional measurements characterizing airflow near the aircraft;
evaluating an error between an airflow parameter value predicted by the computer model and a respective airflow parameter value from the one or more additional measurements; and
varying at least one flight parameter of the aircraft in response to the evaluated error to cause a positional change of the aircraft.
2. The method of claim 1 , wherein at least some of the measurements are collected by at least one other aircraft flying in close formation with the aircraft.
3. The method of claim 1 , wherein at least some measurements are collected by a sensor array.
4. The method of claim 3 , wherein the sensor array includes at least one of a differential airflow probe, a vane airflow probe, a hot wire probe, or a hot film probe.
5. The method of claim 1 , wherein the collecting comprises measuring using a vortex eye sensor.
6. The method of claim 1 , wherein the analyzing comprises at least one of filtering or averaging collected measurement data.
7. The method of claim 6 , wherein the analyzing comprises using Kalman filters to filter collected measurement data.
8. The method of claim 1 , wherein measurements collected during the collecting include at least one of airflow velocity, airflow speed, airflow direction, air pressure, air temperature, or an aircraft angle of attack of the aircraft.
9. The method of claim 1 , wherein at least some measurements collected during the collecting are derived from flight control signals applied to one or more control surfaces of the aircraft.
10. The method of claim 1 , further comprising varying at least one flight parameter of the aircraft prior to obtaining at least one measurement of the one or more additional measurements.
11. The method of claim 10 , wherein the at least one flight parameter includes at least one of an aircraft angle of attack, heading, altitude or velocity.
12. The method of claim 1 , wherein the computer model created during the creating is a 3D model of a vortex field.
13. The method of claim 12 , wherein creating a computer model comprises using a horseshoe vortex model.
14. The method of claim 12 , wherein creating a computer model comprises using a single vortex model.
15. The method of claim 12 , wherein creating a computer model comprises modeling a relative position of a vortex eye.
16. The method of claim 12 , wherein creating a computer model comprises modeling a flight direction toward a vortex eye.
17. The method of claim 12 , further comprising changing a relative position of the aircraft relative to the vortex field.
18. The method of claim 1 , further including adjusting the model based on the evaluating.