US-12617559-B2 - Movement prediction apparatus

US12617559B2US 12617559 B2US12617559 B2US 12617559B2US-12617559-B2

Abstract

A movement prediction apparatus including first and second light output devices, a light reception device, and a processor. The first light output device outputs output-light having a spectral component of a first optical frequency comb of which a frequency comb interval is a first interval. The second light output device outputs reference light having a spectral component of a second optical frequency comb of which a frequency comb interval is a second interval. The light reception device receives combination light that is a combination of the output-light, reflection light that is the output-light reflected by a flying object rotor wing, and the reference light, and measures a distance to the rotor wing based on the combination light. The processor calculates a rotation amount that represents a rotational speed of the rotor wing based on a change amount of the measured distance, and predicts a movement of the flying object.

Inventors

Atsushi Ochiai
Yoshinori Kamiya

Assignees

MITSUBISHI HEAVY INDUSTRIES, LTD.

Dates

Publication Date: 20260505
Application Date: 20211201
Priority Date: 20210129

Claims (10)

1 . A movement prediction apparatus comprising: a first light output device configured to output output-light having a spectral component of a first optical frequency comb of which a frequency comb interval is a first interval; a second light output device configured to output reference light having a spectral component of a second optical frequency comb of which a frequency comb interval is a second interval different from the first interval; a light reception device configured to receive first combination light that is a combination of standard light that is a first part of the output-light, first reflection light that is a second part of the output-light reflected by a first rotor wing of an flying object having a plurality of rotor wing s, and the reference light, to measure a first distance to the first rotor wing based on the first combination light; and a processor configured to calculate a first rotation amount that represents a rotational speed of the first rotor wing based on a change amount of the measured first distance, and predict a movement of the flying object based on a change of the calculated first rotation amount.
2 . The movement prediction apparatus according to claim 1 , wherein the processor is further configured to calculate the first rotation amount based on a period of the change amount of the first distance.
3 . The movement prediction apparatus according to claim 1 , wherein the processor is further configured to calculate the first rotation amount based on an amount of time required for reaching a predetermined number of times that the change amount of the measured first distance from an average of the first distance exceeds a threshold value.
4 . The movement prediction apparatus according to claim 3 , wherein the threshold value is determined based on a difference between the average of the first distance and a distance of the measured first distance that is the furthest from the average.
5 . The movement prediction apparatus according to claim 1 , wherein the processor is further configured to determine a rotation direction of the first rotor wing based on the change amount of the first distance.
6 . The movement prediction apparatus according to claim 1 , wherein the processor is further configured to determine a rotation direction of the first rotor wing based on a position of the first rotor wing where the second part of the output-light irradiates and the change amount of the first distance.
7 . The movement prediction apparatus according to claim 1 , wherein the processor is further configured to determine a rotation direction of the first rotor wing based on: whether a position where the second part of the output-light irradiates is on a left side or a right side of the first rotor wing; and whether an increase or a decrease in the first distance that is periodically measured changes relatively rapidly.
8 . The movement prediction apparatus according to claim 7 , wherein the light reception device is further configured to receive second combination light that is a combination of the standard light, second reflection light that is the second part of the output-light reflected by a second rotor wing of the flying object, and the reference light, to measure a second distance to the second rotor wing based on the second combination light, and wherein the processor is further configured to: calculate a second rotation amount that represents a rotational speed of the second rotor wing based on a change amount of the measured second distance; determine a rotation direction of the second rotor wing based on the change of the second rotation amount; and predict the movement of the flying object based on the rotation direction of the first rotor wing, the change of the first rotation amount, the rotation direction of the second rotor wing, and the change of the second rotation amount.
9 . The movement prediction apparatus according to claim 1 , further comprising an imaging device configured to capture an image of the flying object, wherein the processor is further configured to: judge the movement of the flying object based on the captured image of the flying object; and update a relationship between the change of the first rotation amount and a ratio of a change of the predicted movement of the flying object, based on the movement of the flying object determined from the image and the movement of the flying object predicted from the first rotation amount.
10 . The movement prediction apparatus according to claim 1 , further comprising a laser oscillator configured to radiate a laser beam, wherein the processor is further configured to control an irradiation position of the radiated laser beam based on the predicted movement of the flying object.

Description

TECHNICAL FIELD The present invention relates to a movement prediction apparatus. BACKGROUND In recent years, research has been conducted on techniques of predicting a movement of a mobile object, especially a flying object such as a small unmanned aerial vehicle (UAV). Patent Literature 1 discloses an image data processor that periodically captures images of a mobile object and predicts a movement of the mobile object based on the captured images. In addition, as a method of remotely measuring a position of a mobile object, Patent Literature 2 and Non-Patent Literature 1 disclose methods of using two optical frequency combs. CITED REFERENCE Patent Literature [Patent Literature 1] Japanese Patent Publication No. 2009-171369[Patent Literature 2] US Patent Publication No. 2011/0285980 Non-Patent Literature [Non-Patent Literature 1] Zebin Zhu et al., “Dual-Comb Ranging”, (on line), October 2018, Elsevier, [Searched on Oct. 21, 2020], Internet (URL: https://www.sciencedirect.com/science/article/pii/S2095809918303783) SUMMARY In connection with the above situation, an objective is to provide a movement prediction apparatus that can predict a movement of a flying object with high accuracy. Other objectives will be understood from following disclosures and descriptions of the embodiments. A movement prediction apparatus according to an embodiment in order to achieve the above objective is provided with a first light output device, a second light output device, a light reception device, and a processor. The first light output device outputs output-light having a spectral component of a first optical frequency comb of which a frequency comb interval is a first interval. The second light output device outputs reference light having a spectral component of a second optical frequency comb of which a frequency comb is a second interval different from the first interval. The light reception device receives first combination light that is a combination of the output-light, reflection light that is the output-light reflected by a first rotor wing of a flying object having a plurality of rotor wings, and reference light, to measure a first distance to the first rotor wing based on the first combination light. The processor calculates a first rotation amount that represents a rotational speed of the first rotor wing based on a change amount of the measured first distance, and predicts a movement of the flying object based on a change of the calculated first rotation amount. According to the above embodiment, the movement prediction apparatus can predict a movement of a flying object with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a movement prediction apparatus according to an embodiment. FIG. 2A is a diagram for describing output-light that a first light output device outputs in an embodiment. FIG. 2B is a diagram for describing output-light that a first light output device outputs in an embodiment. FIG. 3 is a diagram for describing combination light that a light reception device receives in an embodiment. FIG. 4 is a configuration diagram of a controller according to an embodiment. FIG. 5 is a configuration diagram of a movement prediction program according to an embodiment. FIG. 6 is a flowchart that shows an operation of a movement prediction apparatus according to an embodiment. FIG. 7A is a diagram for describing a relationship between a measured distance from a measurement device to a rotor wing and a rotation amount of the rotor wing in an embodiment. FIG. 7B is a diagram for describing a relationship between a measured distance from a measurement device to a rotor wing and a rotation amount of the rotor wing in an embodiment. FIG. 7C is a diagram for describing a relationship between a measured distance from a measurement device to a rotor wing and a rotation amount of the rotor wing in an embodiment. FIG. 7D is a diagram for describing a relationship between a measured distance from a measurement device to a rotor wing and a rotation amount of the rotor wing in an embodiment. FIG. 7E is a diagram for describing a relationship between a measured distance from a measurement device to a rotor wing and a rotation amount of the rotor wing in an embodiment. FIG. 8 is a diagram for describing a relationship between a measured distance from a measurement device to a rotor wing and a rotation amount of the rotor wing in an embodiment. FIG. 9 is a configuration diagram of a movement prediction apparatus according to an embodiment. FIG. 10 is a configuration diagram of a movement prediction apparatus according to an embodiment. DETAILED DESCRIPTION Embodiment 1 As shown in FIG. 1, a movement prediction apparatus 100 according to an embodiment outputs output-light 310 to a flying object 10 and receives reflection light 320 thereof to predict a movement of the flying object 10 such as an ascent, a descent, a turning, an acceleration, a deceleration, a change of attitude, or the like.