ESTIMATION OF WIND MAGNITUDE AND DIRECTION

• US 20110251793A1
• Filed: 02/16/2011
• Published: 10/13/2011
• Est. Priority Date: 02/16/2010
• Status: Abandoned Application

• Current Assignee: Atair Aerospace, Inc.
• Original Assignee: Atair Aerospace, Inc.
• Inventors: Calise, Anthony
• Application Number:
  US13/028,544
• Publication Number:
  US 20110251793A1
• Time in Patent Office: Days
• US Class Current: 702/3
• CPC Class Codes: G01P 5/001 Full-field flow measurement, e.g. determining flow velocity and direction in a whole region at the same time, flow visualisation

Abstract

The present invention relates to a method of providing a nearly continuously updated, on-line estimate of wind magnitude and direction when in turning flight and more particularly, relates to a method that requires only a GPS receiver and y- and z-body axis mounted gyros.

Claims

1. A method of providing a nearly continuously updated, on-line estimate of wind magnitude and direction when in turning flight comprising the acts of:

calculating a heading rate of a body frame using gyro outputs using a first equation;

{circumflex over ({dot over (ψ

)}=√

{square root over (ω

_y²+ω

_z²)}sign{ω

_z), wherein ω

_y and ω

_z are the gyro outputs.

2. The method of claim 1, further including the acts of:

denoting points on a turn where GPS sensed inertial horizontal speed passes through a maximum (Vmax) point and a minimum (Vmin) point, wherein Vmax and Vmin are determined by comparing each sample of a GPS indicated horizontal speed with the last determined maximum and minimum value over a 360 degree turn and a change in the GPS indicated inertial heading between these points is denoted as δ

ψ

_i.

3. The method of claim 2, further including the act of:

calculating the net bias error in {circumflex over ({dot over (ψ

)} using the following equation;

{circumflex over ({dot over (ψ

)}_bias=(δ

ψ

_b−

δ

ψ

_i)/δ

t wherein an integral body heading rate is denoted as δ

ψ

_b, and a time difference is denoted as δ

t.

4. A method of estimating wind magnitude and direction comprising the acts of:

completing a first turn;

calculating an first estimate for a heading rate after completing the first turn using a first equation;

{circumflex over ({dot over (ψ

)}=√

{square root over (ω

_y²+ω

_z²)}sign{ω

_z);

completing a second turn; and

calculating a change in bias from the first turn to the second turn using a second equation;

{circumflex over ({dot over (ψ

)}_bias=(δ

ψ

_b−

δ

ω

_i)/δ

t.

5. The method of claim 4 further comprising the act of:

calculating a wind speed and direction using the following equation;

Wspeed1=(V_i_max−

V_i_min)/2

psi_—

w1=psi_—

i_max

6. The method of claim 4 further comprising the act of:

calculating a wind speed and direction using the following equation;

Wx=(Vi_north_max+Vi_north_min)/2

Wy=(Vi_east_max+Vi_east_min)/2;

Wspeed2=sqrt(Wx*Wx+Wy*Wy)

psiw2=a tan 2(Wy,Wx)