Airframe-embedded ultrasonic transducers

Patent metadata

Field	Value
Publication number	US-10101443-B1
Application number	US-201615368532-A
Country	US
Kind code	B1
Filing date	Dec 2, 2016
Priority date	Dec 2, 2016
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

Aerial vehicles may be outfitted with one or more ultrasonic anemometers, each having ultrasonic transducers embedded into external surfaces. The transducers may be aligned and configured to transmit acoustic signals to one another, and receive acoustic signals from one another, along one or more paths or axes. Elapsed times of signals transmitted and received by pairs of transducers may be used to determine air speeds along the paths or axes. Where two or more pairs of transducers are provided, a net vector may be derived based on air speeds determined along the paths or axes between the pairs of the transducers, and used to generate control signals for maintaining the aerial vehicle on a desired course, at a desired speed or altitude, or in a desired orientation. The transducers may be dedicated for use in an anemometer, or may serve multiple purposes, and may be reoriented or reconfigured as necessary.

First claim

What is claimed is:

1. An unmanned aerial vehicle comprising:
an airframe;
at least one propulsion motor mounted to the airframe;
at least one movable control surface mounted to the airframe;
a first ultrasonic transducer rotatably mounted to a first location on the airframe by a first rotatable mount, wherein the first ultrasonic transducer is configured to rotate about a first axis defined by the first rotatable mount;
a second ultrasonic transducer rotatably mounted to a second location on the airframe by a second rotatable mount, wherein the second ultrasonic transducer is configured to rotate about a second axis defined by the second rotatable mount, and wherein the first location and the second location are separated by a first linear distance along a first path;
a control unit having at least one computer processor configured to at least:
cause the first ultrasonic transducer to be aligned toward the second ultrasonic transducer along the first path;
cause the second ultrasonic transducer to be aligned toward the first ultrasonic transducer along the first path;
cause the first ultrasonic transducer to transmit a first acoustic signal toward the second ultrasonic transducer along the first path at a first time;
capture first acoustic energy by the second ultrasonic transducer at a second time, wherein the first acoustic energy comprises the first acoustic signal;
cause the second ultrasonic transducer to transmit a second acoustic signal toward the first ultrasonic transducer along the first path at a third time;
capture second acoustic energy by the first ultrasonic transducer at a fourth time, wherein the second acoustic energy comprises the second acoustic signal; and
determine a first elapsed time based at least in part on a difference between the second time and the first time;
determine a second elapsed time based at least in part on a difference between the fourth time and the third time;
determine a first air speed along the first path based at least in part on the first linear distance, the first elapsed time and the second elapsed time;
cause the first ultrasonic transducer to be aligned along a second path, wherein the second path is not the first path;
cause the first ultrasonic transducer to transmit a third acoustic signal along the second path at a fifth time; and
capture third acoustic energy by the first ultrasonic transducer at a sixth time, wherein the third acoustic energy comprises the third acoustic signal.

2. The unmanned aerial vehicle of claim 1 , wherein the first air speed is a product of one-half the first linear distance and a difference between a reciprocal of the second elapsed time and a reciprocal of the first elapsed time.

3. The unmanned aerial vehicle of claim 1 , wherein the control unit is further configured to at least:
determine a third elapsed time based at least in part on a difference between the sixth time and the fifth time; and
determine at least one of a position of a first object or a velocity of the first object based at least in part on the third elapsed time.

4. The unmanned aerial vehicle of claim 1 , further comprising:
a third ultrasonic transducer rotatably mounted to a third location on the airframe by a third rotatable mount, wherein the third ultrasonic transducer is configured to rotate about a third axis defined by the third rotatable mount; and
a fourth ultrasonic transducer rotatably mounted to a fourth location on the airframe by a fourth rotatable mount, wherein the fourth ultrasonic transducer is configured to rotate about a fourth axis defined by the fourth rotatable mount, and wherein the third location and the fourth location are separated by a second linear distance along a third path,
wherein the at least one computer processor is further configured to at least:
cause the third ultrasonic transducer to transmit a fourth acoustic signal toward the fourth ultrasonic transducer along the third path at a seventh time;
capture fourth acoustic energy by the fourth ultrasonic transducer at an eighth time, wherein the fourth acoustic energy comprises the fourth acoustic signal;
cause the fourth ultrasonic transducer to transmit a fifth acoustic signal toward the third ultrasonic transducer along the third path at a ninth time;
capture fifth acoustic energy by the fourth ultrasonic transducer at a tenth time, wherein the fifth acoustic energy comprises the fifth acoustic signal; and
determine a fourth elapsed time based at least in part on a difference between the eighth time and the seventh time;
determine a fifth elapsed time based at least in part on a difference between the tenth time and the ninth time;
determine a second air speed along the third path based at least in part on the second linear distance, the fourth elapsed time and the fifth elapsed time;
cause the third ultrasonic transducer to be aligned along a fourth path, wherein the fourth path is not the third path;
cause the third ultrasonic transducer to transmit a sixth acoustic signal along the fourth path at an eleventh time; and
capture sixth acoustic energy by the third ultrasonic transducer at a twelfth time, wherein the sixth acoustic energy comprises the sixth acoustic signal.

5. The unmanned aerial vehicle of claim 4 , wherein the at least one computer processor is further configured to at least:
determine a net vector representative of an air velocity of the aerial vehicle based at least in part on the first air speed, the first path, the second air speed and the third path;
identify at least one of a desired course, a desired speed or a desired altitude for the unmanned aerial vehicle; and
operate the at least one of the at least one propulsion motor or the at least one movable control surface based at least in part on the air velocity to cause the unmanned aerial vehicle to travel at the at least one of the desired course, the desired speed or the desired altitude.

6. A method comprising:
transmitting, by a first transducer operating in a first mode, a first acoustic signal in at least a first direction along at least a first path at a first time, wherein the first transducer is movably mounted to a first portion of an aerial vehicle;
receiving, by a second transducer operating in the first mode, at least the first acoustic signal at a second time, wherein the second transducer is mounted to a second portion of the aerial vehicle, and wherein the second transducer and the first transducer are separated by a first linear distance;
determining a first elapsed time of the first acoustic signal, wherein the first elapsed time comprises a difference between the second time and the first time;
determining a relative air speed along the first path based at least in part on the first linear distance and the first elapsed time;
causing the first transducer to be aligned along at least a second path, wherein the second path is not the first path; and
transmitting, by the first transducer operating in a second mode, a second acoustic signal in at least a second direction along at least the second path at a third time.

7. The method of claim 6 , wherein determining the relative air speed along the first path comprises:
transmitting, by the second transducer, a third acoustic signal in at least a third direction along the first path at a fourth time, wherein the third direction is opposite to the first direction;
receiving, by the first transducer, the third acoustic signal at a fifth time; and
determining a second elapsed time of the third acoustic signal, wherein the second elapsed time comprises a difference between the fifth time and the fourth time,
wherein the relative air speed along the first path is determined based at least in part on the first linear distance, the first elap

Assignees

• Amazon Tech Inc

Inventors

• Legrand Iii Louis Leroi
• Parent Gershon
• Wilcox Scott Michael

Classifications

• G01P5/245

  by measuring transit time of acoustical waves (measuring propagation velocity of acoustical waves per se G01H5/00) · CPC title

• B64D43/02

  for indicating aircraft speed or stalling conditions · CPC title

• G01S11/14 Primary

  using ultrasonic, sonic or infrasonic waves · CPC title

• B64C13/16 Primary

  actuated automatically, e.g. responsive to gust detectors · CPC title

• B64C39/024

  of the remote controlled vehicle type, i.e. RPV · CPC title