# US 10,871,502 B2 · Rotating three-dimensional ultrasonic anemometer and method of measuring three-dimensional wind velocity using the same

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- Number: US 10,871,502 B2
- Document ID: US10871502B2
- Status: Granted
- Kind: B2
- Application number: 16/315,564
- Filed: 2018-04-23
- Published: 2019-06-20
- Granted: 2020-12-22
- Earliest claimed: 2017-07-05
- Assignees: Korea Aerospace Research Institute
- Applicants: Korea Aerospace Research Institute
- Inventors: Byeong Hee Chang; Seunghoon Lee; Tae Hwan Cho; Yang Won Kim
- Web page: https://patentgrep.com/patent/US10871502B2

## CPC

- G01P 5/06: using rotation of vanes (measuring speed of rotating shafts G01P3/00)
- F03D 3/0409: {surrounding the rotor (F03D3/0427 takes precedence)}
- F03D 17/00: Monitoring or testing of wind motors, e.g. diagnostics (testing during commissioning of wind motors F03D13/30)
- G01H 11/06: by electric means
- G01P 5/24: by measuring the direct influence of the streaming fluid on the properties of a detecting acoustical wave
- G01P 5/248: {by measuring phase differences}
- G01P 21/025: {for measuring speed of fluids; for measuring speed of bodies relative to fluids (for measuring volume flow G01F25/10)}
- F05B 2270/32: Wind speeds
- F05B 2270/321: Wind directions
- Y02E 10/74: Wind turbines with rotation axis perpendicular to the wind direction
- G01P: MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT (measuring or recording blood flow A61B5/02, A61B8/06; monitoring speed or deceleration of electrically-propelled vehicles B60L3/00; vehicle lighting systems adapted to indicate speed B60Q1/54; determining position or course in navigation, measuring ground distance in geodesy or surveying G01C; combined measuring devices for measuring two or more variables of movement G01C23/00; measuring velocity of sound G01H; measuring velocity of light G01J7/00; measuring direction or velocity of solid objects by reception or emission of radiowaves or other waves and based on propagation effects, e.g. Doppler effect, propagation time, direction of propagation, G01S; measuring speed of nuclear radiation G01T; measuring acceleration of gravity G01V; {measuring or recording the speed of trains B61L23/00; speed indicators incorporated in motor vehicles B60K35/00; measuring frequency or phase G01R; traffic control G08G})
- F03D: WIND MOTORS
- G01H: MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
- F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Provided are a three-dimensional (3D) ultrasonic anemometer, a 3D wind velocity measuring method, and a wind turbine. The 3D ultrasonic anemometer includes: an ultrasonic sensor including three pairs of ultrasonic transceivers arranged in different directions, wherein the ultrasonic sensor is installed at a rotation body rotating around a rotation axis and rotates around the rotation axis together with the rotation body; a signal processor outputting a 3D sensed wind velocity sensed by the ultrasonic sensor; and a coordinate converter converting the 3D sensed wind velocity into a 3D fixed wind velocity on a fixed coordinate system by using a rotation angle φ of the rotation body.

## Claims

### Claim 1

A three-dimensional (3D) ultrasonic anemometer comprising:
an ultrasonic sensor comprising three pairs of ultrasonic transceivers arranged in different directions, wherein the ultrasonic sensor is installed at a rotation body rotating around a rotation axis and rotates around the rotation axis together with the rotation body;
a signal processor outputting a 3D sensed wind velocity sensed by the ultrasonic sensor; and
a coordinate converter converting the 3D sensed wind velocity into a 3D fixed wind velocity on a fixed coordinate system by using a rotation angle φ of the rotation body.

### Claim 2 (depends on 1)

The 3D ultrasonic anemometer of claim 1, further comprising a rotation angle sensor comprising a gravity sensor rotating together with the rotation body, wherein the rotation angle sensor senses the rotation angle φ of the rotation body by using the gravity sensor and outputs the rotation angle φ to the coordinate converter.

### Claim 3 (depends on 1)

The 3D ultrasonic anemometer of claim 1, wherein the coordinate converter receives, in real time, information about the rotation angle φ of the rotation body from an external device including the rotation body.

### Claim 4 (depends on 1)

The 3D ultrasonic anemometer of claim 1, wherein the 3D sensed wind velocity is defined on a sensing coordinate system of the ultrasonic sensor, and
an X axis of the fixed coordinate system is in the same direction as the rotation axis, and the X axis, a Y axis, and a Z axis of the fixed coordinate system are perpendicular to each other.

### Claim 5 (depends on 4)

The 3D ultrasonic anemometer of claim 4, wherein, when the ultrasonic sensor is aligned on the rotation axis such that an Xs axis of the sensing coordinate system is arranged on the rotation axis,
the coordinate converter calculates the 3D fixed wind velocity according to [Equation] below based on the 3D sensed wind velocity and the rotation angle φ
U=Us
V=Vs cos(φ)−Ws sin(φ)
W=Vs sin(φ)+Ws cos(φ) [Equation].

### Claim 6 (depends on 4)

The 3D ultrasonic anemometer of claim 4, wherein the coordinate converter comprises:
a first coordinate converter converting the 3D sensed wind velocity on the sensing coordinate system into a 3D rotation wind velocity on a rotating coordinate system; and
a second coordinate converter converting the 3D rotation wind velocity on the rotating coordinate system into the 3D fixed wind velocity on the fixed coordinate system,
wherein an X′ axis of the rotating coordinate system is parallel to the X axis of the fixed coordinate system, and a Y′ axis and a Z′ axis of the rotating coordinate system are rotated by the rotation angle φ from the Y axis and the Z axis of the fixed coordinate system, respectively.

### Claim 7 (depends on 6)

The 3D ultrasonic anemometer of claim 6, wherein, when the ultrasonic sensor is installed on the rotation body such that an Xs axis of the sensing coordinate system is spaced apart from the rotation axis by a spacing distance R at a spacing angle δ, and the rotation body rotates around the rotation axis at an angular velocity ω,
the first coordinate converter calculates the 3D rotation wind velocity according to [Equation] below based on the 3D sensed wind velocity and the spacing angle δ,
wherein the spacing angle δ is defined as an angle toward a Zs axis with respect to a Ys axis of the sensing coordinate system
U′=Us
V′=Vs−Rω sin(δ)
W′=Ws+Rω cos(δ) [Equation].

### Claim 8 (depends on 7)

The 3D ultrasonic anemometer of claim 7, wherein the first coordinate converter calculates the angular velocity ω based on the rotation angle φ of the rotation body.

### Claim 9 (depends on 7)

The 3D ultrasonic anemometer of claim 7, wherein the spacing distance R is calculated by dividing a magnitude of the 3D sensed wind velocity in a windless state by the angular velocity ω.

### Claim 10 (depends on 7)

The 3D ultrasonic anemometer of claim 7, wherein the spacing angle δ is calculated as tan−1(−Vs/Ws) based on the 3D sensed wind velocity in a windless state.

### Claim 11 (depends on 7)

The 3D ultrasonic anemometer of claim 7, wherein the second coordinate converter calculates the 3D fixed wind velocity according to [Equation] below based on the 3D rotation wind velocity and the rotation angle φ
U=U′
V=V′ cos(φ)−W′ sin(φ)
W=V′ sin(φ)+W′ cos(φ) [Equation].

### Claim 12 (depends on 4)

The 3D ultrasonic anemometer of claim 4, wherein the coordinate converter comprises:
a first coordinate converter converting the 3D sensed wind velocity on the sensing coordinate system into a 3D offset wind velocity on an offset coordinate system;
a second coordinate converter converting the 3D offset wind velocity on the offset coordinate system into a 3D rotation wind velocity on a rotating coordinate system; and
a third coordinate converter converting the 3D rotation wind velocity on the rotating coordinate system into the 3D fixed wind velocity on the fixed coordinate system,
wherein an X″ axis of the offset coordinate system is spaced apart from an X′ axis of the rotating coordinate system by a spacing distance R at a spacing angle δ, and a Y″ axis and a Z″ axis of the offset coordinate system are parallel to a Y′ axis and a Z′ axis of the rotating coordinate system, respectively, and
the X′ axis of the rotating coordinate system is parallel to the X axis of the fixed coordinate system, and the Y′ axis and the Z′ axis of the rotating coordinate system are rotated by the rotation angle φ from the Y axis and the Z axis of the fixed coordinate system, respectively.

### Claim 13 (depends on 12)

The 3D ultrasonic anemometer of claim 12, wherein, when the ultrasonic sensor is installed on the rotation body such that the sensing coordinate system is the same as a coordinate system rotated by a third offset angle θz with respect to a third axis of a coordinate system rotated by a second offset angle θy with respect to a second axis of a coordinate system rotated by a first offset angle θx with respect to a first axis of the offset coordinate system, and the rotation body rotates around the rotation axis at an angular velocity ω,
the first coordinate converter calculates the 3D offset wind velocity according to [Equation] below based on the 3D sensed wind velocity and the first to third offset angles θx, θy, and θz
[
U
″
V
″
W
″
]
=
[
1
0
0
0
cos
⁢
⁢
θ
⁢
⁢
x
-
sin
⁢
⁢
θ
⁢
⁢
x
0
sin
⁢
⁢
θ
⁢
⁢
x
cos
⁢
⁢
θ
⁢
⁢
x
]
⁡
[
cos
⁢
⁢
θ
⁢
⁢
y
0
sin
⁢
⁢
θ
⁢
⁢
y
0
1
0
-
sin
⁢
⁢
θ
⁢
⁢
y
0
cos
⁢
⁢
θ
⁢
⁢
y
]
⁢
[
cos
⁢
⁢
θ
⁢
⁢
z
-
sin
⁢
⁢
θ
⁢
⁢
z
0
sin
⁢
⁢
θ
⁢
⁢
z
cos
⁢
⁢
θ
⁢
⁢
z
⁢
0
0
0
1
]
⁡
[
Us
Vs
Ws
]
.
[
Equation
]

### Claim 14 (depends on 13)

The 3D ultrasonic anemometer of claim 13, wherein the first to third offset angles θx, θy, and θz are calculated according to [Equation] below based on the spacing distance R, the angular velocity ω, the spacing angle δ, and the 3D sensed wind velocity measured in a windless state, and
the spacing angle δ is defined as an angle toward the Z″ axis with respect to the Y″ axis of the offset coordinate system
[
0
R
⁢
⁢
ω
⁢
⁢
sin
⁢
⁢
δ
-
R
⁢
⁢
ω
⁢
⁢
cos
⁢
⁢
δ
]
=
[
1
0
0
0
cos
⁢
⁢
θ
⁢
⁢
x
-
sin
⁢
⁢
θ
⁢
⁢
x
0
sin
⁢
⁢
θ
⁢
⁢
x
cos
⁢
⁢
θ
⁢
⁢
x
]
⁡
[
cos
⁢
⁢
θ
⁢
⁢
y
0
sin
⁢
⁢
θ
⁢
⁢
y
0
1
0
-
sin
⁢
⁢
θ
⁢
⁢
y
0
cos
⁢
⁢
θ
⁢
⁢
y
]
⁢
[
cos
⁢
⁢
θ
⁢
⁢
z
-
sin
⁢
⁢
θ
⁢
⁢
z
0
sin
⁢
⁢
θ
⁢
⁢
z
cos
⁢
⁢
θ
⁢
⁢
z
0
0
0
1
]
⁡
[
Us
Vs
Ws
]
.
[
Equation
]

### Claim 15 (depends on 12)

The 3D ultrasonic anemometer of claim 12, wherein the second coordinate converter calculates the 3D rotation wind velocity according to [Equation 1] below based on the 3D offset wind velocity and the spacing angle δ,
the third coordinate converter calculates the 3D fixed wind velocity according to [Equation 2] below based on the 3D rotation wind velocity and the rotation angle φ, and
the spacing angle δ is defined as an angle toward a Zs axis with respect to a Ys axis of the sensing coordinate system
U′=U″
V′=V″−Rω sin(δ)
W′=W″+Rω cos(δ) [Equation 1]
U=U′
V=V′ cos(φ)−W′ sin(φ)
W=V′ sin(φ)+W′ cos(φ) [Equation 2].

### Claim 16

A three-dimensional (3D) wind velocity measuring method comprising:
receiving a 3D sensed wind velocity on a sensing coordinate system, which is sensed by a 3D ultrasonic anemometer that is installed at a rotation body rotating around a rotation axis and rotates around the rotation axis together with the rotation body;
receiving a rotation angle φ of the rotation body; and
converting the 3D sensed wind velocity on the sensing coordinate system into a 3D fixed wind velocity on a fixed coordinate system by using the rotation angle φ.

### Claim 17 (depends on 16)

The 3D wind velocity measuring method of claim 16, wherein an X axis of the fixed coordinate system is in the same direction as the rotation axis, and the X axis, a Y axis, and a Z axis of the fixed coordinate system are perpendicular to each other.

### Claim 18 (depends on 17)

The 3D wind velocity measuring method of claim 17, wherein, when an Xs axis of the sensing coordinate system is located on the rotation axis,
in the converting of the 3D sensed wind velocity into the 3D fixed wind velocity,
the 3D fixed wind velocity is calculated according to [Equation] below based on the 3D sensed wind velocity and the rotation angle φ
U=Us
V=Vs cos(φ)−Ws sin(φ)
W=Vs sin(φ)+Ws cos(φ) [Equation].

### Claim 19 (depends on 17)

The 3D wind velocity measuring method of claim 17, wherein the converting of the 3D sensed wind velocity into the 3D fixed wind velocity comprises:
converting the 3D sensed wind velocity on the sensing coordinate system into a 3D rotation wind velocity on a rotating coordinate system; and
converting the 3D rotation wind velocity on the rotating coordinate system into the 3D fixed wind velocity on the fixed coordinate system,
wherein an X′ axis of the rotating coordinate system is parallel to the X axis of the fixed coordinate system, and a Y′ axis and a Z′ axis of the rotating coordinate system are rotated by the rotation angle φ from the Y axis and the Z axis of the fixed coordinate system, respectively.

### Claim 20 (depends on 19)

The 3D wind velocity measuring method of claim 19, wherein, when an Xs axis of the sensing coordinate system is spaced apart from the rotation axis by a spacing distance R at a spacing angle δ and the rotation body rotates around the rotation axis at an angular velocity ω,
the 3D rotation wind velocity is calculated according to [Equation 1] below based on the 3D sensed wind velocity and the spacing angle δ, and
the 3D fixed wind velocity is calculated according to [Equation 2] below based on the 3D rotation wind velocity and the rotation angle φ,
wherein the spacing angle δ is defined as an angle toward a Zs axis with respect to a Ys axis of the sensing coordinate system
U′=Us
V′=Vs−Rω sin(δ)
W′=Ws+Rω cos(δ) [Equation 1]
U=U′
V=V′ cos(φ)−W′ sin(φ)
W=V′ sin(φ)+W′ cos(φ) [Equation 2].

### Claim 21 (depends on 17)

The 3D wind velocity measuring method of claim 17, wherein the converting of the 3D sensed wind velocity into the 3D fixed wind velocity comprises:
converting the 3D sensed wind velocity on the sensing coordinate system into a 3D offset wind velocity on an offset coordinate system;
converting the 3D offset wind velocity on the offset coordinate system into a 3D rotation wind velocity on a rotating coordinate system; and
converting the 3D rotation wind velocity on the rotating coordinate system into the 3D fixed wind velocity on the fixed coordinate system,
wherein an X″ axis of the offset coordinate system is spaced apart from an X′ axis of the rotating coordinate system by a spacing distance R at a spacing angle δ, and a Y″ axis and a Z″ axis of the offset coordinate system are parallel to a Y′ axis and a Z′ axis of the rotating coordinate system, respectively, and
the X′ axis of the rotating coordinate system is parallel to the X axis of the fixed coordinate system, and the Y′ axis and the Z′ axis of the rotating coordinate system are rotated by the rotation angle φ from the Y axis and the Z axis of the fixed coordinate system, respectively.

### Claim 22 (depends on 21)

The 3D wind velocity measuring method of claim 21, wherein, when the sensing coordinate system is the same as a coordinate system rotated by a third offset angle θz with respect to a third axis of a coordinate system rotated by a second offset angle θy with respect to a second axis of a coordinate system rotated by a first offset angle θx with respect to a first axis of the offset coordinate system and the rotation body rotates around the rotation axis at an angular velocity ω,
the 3D offset wind velocity is calculated according to [Equation 1] below based on the 3D sensed wind velocity and the first to third offset angles θx, θy, and θz,
the 3D rotation wind velocity is calculated according to [Equation 2] below based on the 3D offset wind velocity and the spacing angle δ, and
the 3D fixed wind velocity is calculated according to [Equation 3] below based on the 3D rotation wind velocity and the rotation angle φ,
wherein the spacing angle δ is defined as an angle toward a Zs axis with respect to a Ys axis of the sensing coordinate system
[
U
″
V
″
W
″
]
=
[
1
0
0
0
cos
⁢
⁢
θ
⁢
⁢
x
-
sin
⁢
⁢
θ
⁢
⁢
x
0
sin
⁢
⁢
θ
⁢
⁢
x
cos
⁢
⁢
θ
⁢
⁢
x
]
⁡
[
cos
⁢
⁢
θ
⁢
⁢
y
0
sin
⁢
⁢
θ
⁢
⁢
y
0
1
0
-
sin
⁢
⁢
θ
⁢
⁢
y
0
cos
⁢
⁢
θ
⁢
⁢
y
]
⁢
[
cos
⁢
⁢
θ
⁢
⁢
z
-
sin
⁢
⁢
θ
⁢
⁢
z
0
sin
⁢
⁢
θ
⁢
⁢
z
cos
⁢
⁢
θ
⁢
⁢
z
⁢
0
0
0
1
]
⁡
[
Us
Vs
Ws
]
[
Equation
⁢
⁢
1
]
⁢
U
′
=
U
″
⁢
⁢
⁢
V
′
=
V
″
-
R
⁢
⁢
ω
⁢
⁢
sin
⁢
⁢
(
δ
)
⁢
⁢
⁢
W
′
=
W
″
+
R
⁢
⁢
ω
⁢
⁢
cos
⁡
(
δ
)
[
Equation
⁢
⁢
2
]
⁢
U
=
U
′
⁢
⁢
⁢
V
=
V
′
⁢
cos
⁡
(
φ
)
-
W
′
⁢
sin
⁢
⁢
(
φ
)
⁢
⁢
⁢
W
=
V
′
⁢
sin
⁡
(
φ
)
+
W
′
⁢
cos
⁡
(
φ
)
.
[
Equation
⁢
⁢
3
]

### Claim 23

A wind turbine comprising:
a hub rotating along a rotation axis;
rotation blades installed at the hub to rotate the hub by wind power;
a nacelle generating electricity by the rotation of the hub;
a three-dimensional (3D) ultrasonic anemometer outputting a 3D fixed wind velocity on a fixed coordinate system; and
a controller controlling at least one of a pitch angle of the rotation blades and a yaw angle of the rotation axis by using the 3D fixed wind velocity,
wherein the 3D ultrasonic anemometer comprises:
an ultrasonic sensor comprising three pairs of ultrasonic transceivers arranged in different directions, wherein the ultrasonic sensor is installed at a spinner of the hub rotating around the rotation axis and rotates around the rotation axis together with the hub;
a signal processor outputting a 3D sensed wind velocity on a sensing coordinate system sensed by the ultrasonic sensor; and
a coordinate converter converting the 3D sensed wind velocity into the 3D fixed wind velocity by using a rotation angle φ of the hub.