JP2019138739A - Position measurement device and method for position measurement - Google Patents

Abstract

To provide a position measurement device and a method for position measurement that can accurately measure the position of a target without equipping an attitude control mechanism.SOLUTION: The position measurement device includes: a mobile body; an imaging device equipped in the mobile body, the imaging device imaging a target; a position acquisition unit for acquiring the positional information of the mobile body when the target is in the center of the imaging range of the imaging device, in a first posture and in a second posture of the mobile body in a reflective symmetry; and a position calculation unit for calculating the positional information of the target based on the positional information of the mobile body in the first posture and in the second posture acquired by the position acquisition unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a position measuring device and a position measuring method.

  There has been proposed a position measuring method for measuring the position of an object that is vertically below the moving body from above using a moving body (balloon or helicopter) on which an imaging device is mounted. This position measurement method measures the position of an object by setting the position of the moving object when the object is at the center of a captured image (imaging range) captured vertically below the moving object. It is a method to do.

  However, even if there is an object in the center of the captured image, there is actually no object vertically below the moving object due to a displacement of the mounting position of the imaging device with respect to the moving object or a displacement of the posture of the moving object. In some cases, the position of the moving object and the position of the object are different.

  In order to solve this problem, Japanese Patent Application Laid-Open No. 2004-228688 discloses a moving body provided with a posture control mechanism that controls the posture of the imaging device in order to correct a displacement of the mounting position of the imaging device with respect to the moving body and a displacement of the posture of the moving body. Mounting is disclosed.

JP 2007-240435 A

  The attitude control mechanism can be attached to a large moving body such as a balloon or a helicopter. However, a space for attaching the posture control mechanism cannot be secured for a small mobile body such as a drone, and the posture control mechanism may not be attached. As a result, when a small moving body is used, the position of the object may not be accurately measured.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a position measurement device and a position measurement method capable of accurately measuring the position of an object without attaching a posture control mechanism. .

  One embodiment of the present invention includes a moving body, an imaging device that is mounted on the moving body and picks up an object, and a first posture and a second posture in which the postures of the moving body are mirror-symmetric to each other. The position acquisition unit for acquiring the position information of the moving body when the object is at the center of the imaging range of the imaging device, the first posture acquired by the position acquisition unit, and the first And a position calculation unit that calculates position information of the target object based on position information of the moving body having a posture of 2.

  One aspect of the present invention is the above-described position measurement device, wherein the position calculation unit is an average of position information of the moving body in the first posture and the second posture acquired by the position acquisition unit. The value is the position information of the object.

  One embodiment of the present invention is the above-described position measurement device, in which the first posture and the second posture have the same posture angle and different azimuth angles by 180 °.

  One embodiment of the present invention is the above-described position measurement device, in which the imaging device captures an image below the moving body.

  One aspect of the present invention is a position measurement method for measuring position information of an object using a moving body on which an imaging apparatus that images the object is mounted, and the postures of the moving bodies are mirror-symmetrical with each other. A position acquisition step of acquiring position information of the moving body when the object is at the center of the imaging range of the imaging device in the first attitude and the second attitude, and the position acquisition unit, A position calculating step of calculating position information of the object based on the acquired position information of the moving body in the first posture and the second posture. is there.

  As described above, according to the present invention, it is possible to accurately measure the position of an object without attaching a posture control mechanism.

It is a figure which shows an example of schematic structure of the position measurement apparatus A which concerns on one Embodiment of this invention. It is a block diagram of the control apparatus 4 which concerns on one Embodiment of this invention. It is a figure which shows the 1st attitude | position and 2nd attitude | position which concern on one Embodiment of this invention. It is a flowchart of operation | movement of the object position measurement mode in the control part 11 which concerns on one Embodiment of this invention. It is a figure explaining the problem of the position measuring method of the target object in the past.

  Hereinafter, a position measuring device according to an embodiment of the present invention will be described with reference to the drawings.

  A position measurement device according to an embodiment of the present invention is a device that measures the position of an object using a moving body on which an imaging device is mounted. In the present embodiment, the case where the mobile body is a drone will be described, but the present invention is not limited to this. For example, the moving body may be any flying object such as an unmanned aerial vehicle (UAV) other than a drone, a balloon, an airplane, a helicopter, an autonomous underwater vehicle (AUV) or a remote It may be an underwater unmanned aircraft such as a remotely operated vehicle (ROV). The mobile body may be manned or unmanned.

FIG. 1 is a diagram illustrating an example of a schematic configuration of a position measurement apparatus A according to an embodiment of the present invention.
As shown in FIG. 1, the position measuring device A includes an imaging device 1 and a drone 2.

  The imaging device 1 is mounted on the drone 2. Specifically, the imaging device 1 is fixed to the lower part of the body of the drone 2 and images an object (target object) that exists below the drone 2. This object includes, for example, structures, people, and animals and plants that exist on the ground. The imaging device 1 is electrically connected to the drone 2. Note that the imaging device 1 may be configured to be removable from the drone 2 or may be configured integrally.

  The drone 2 includes a plurality of rotor units 3 and a control device 4.

Each rotor unit 3 includes a rotor 5 and a motor 6.
The rotor 5 is, for example, a propeller. The rotor 5 of each rotor unit 3 is provided on the same plane.

  The motor 6 is connected to the rotor 5 and rotates under the control of the control device 4 to drive the rotor 5 to rotate. The number of rotations (rotational speed) of the motor 6 is controlled by the control device 4.

  The control device 4 can control the rotation of the motor 6 to move the drone 2 in the sky or maintain the flying posture at a predetermined position (hovering).

  Specifically, the control device 4 can generate lift that raises the drone 2 by maintaining the rotational speeds of the motors 6 of the respective rotor units 3 to be substantially the same, and can maintain the airframe of the drone 2 in a horizontal posture. it can. In addition, the control device 4 can control the rotation speed of the motor 6 of each rotor unit 3 independently and tilt the drone 2 to move the fuselage back and forth or right and left.

Further, the control device 4 measures the position of the target object based on the captured image obtained by capturing the target object by the imaging device 1.
Below, the structure of the control apparatus 4 which concerns on one Embodiment of this invention is demonstrated using FIG. FIG. 2 is a block diagram of the control device 4 according to an embodiment of the present invention.

  As shown in FIG. 2, the control device 4 includes a self-position acquisition unit 7, an attitude detection unit 8, an orientation detection unit 9, a drive unit 10, and a control unit 11.

  The self position acquisition unit 7 acquires information on the current position of the drone 2 (hereinafter referred to as “position information”). For example, the self-position acquisition unit 7 acquires the position information of the drone 2 using global coordinates (X, Y) by using GPS (Global Positioning System). The self position acquisition unit 7 outputs the acquired position information of the drone 2 to the control unit 11. For example, the X coordinate indicates latitude and the Y coordinate indicates longitude.

  The attitude detection unit 8 acquires information on the current flight attitude of the drone 2 (hereinafter referred to as “flight attitude information”). For example, the flight attitude information of the drone 2 is information indicating the inclination with respect to the horizontal plane, and is a so-called attitude angle. For example, the posture detection unit 8 is a gyro sensor. Note that the flight attitude information may be represented by a roll angle, a pitch angle, and a yaw angle. The attitude detection unit 8 outputs the flight attitude information of the drone 2 to the control unit 11.

  The azimuth detecting unit 9 detects azimuth information (hereinafter referred to as “azimuth information”). For example, the bearing detection unit 9 detects geomagnetism and detects bearing information based on the detected geomagnetism. Then, the direction detection unit 9 outputs the detected direction information to the control unit 11.

  The drive unit 10 drives each motor 6 to rotate independently based on a drive signal from the control unit 11. That is, the drive unit 10 controls the rotation speed of each motor 6 based on the drive signal from the control unit 11.

  Based on the flight attitude information from the attitude detection unit 8, the control unit 11 can fly the drone 2 while stabilizing the drone 2 in an arbitrary flight attitude. That is, the control unit 11 sends a drive signal for controlling the rotation speed of each motor 6 to the drive unit 10 so as to stabilize the drone 2 in an arbitrary flight posture based on the flight posture information from the posture detection unit 8. Output.

  The control unit 11 can recognize the traveling direction of the drone 2 based on the position information from the self-position acquisition unit 7 and the direction information from the direction detection unit 9, and is set in advance to the flight route or destination. Autonomous flight is possible.

  The control unit 11 has an object position measurement mode in which the position of the target object is measured based on a captured image obtained by capturing the target object by the imaging apparatus 1. Below, the function part for performing operation | movement of the target object position measurement mode of the control part 11 which concerns on this invention is demonstrated.

  The control unit 11 includes an object recognition unit 110, a movement control unit 111, an object position acquisition unit 112, and an object position calculation unit 113. The object position acquisition unit 112 is an example of the “position acquisition unit” in the present invention. The object position calculation unit 113 is an example of the “position calculation unit” in the present invention.

  The object recognition unit 110 acquires a captured image obtained by capturing an image of the object by the imaging device 1 at regular intervals. Then, the object recognition unit 110 recognizes the position of the object in the acquired captured image. Then, the object recognition unit 110 outputs the position of the object in the acquired captured image to the movement control unit 111 at regular intervals.

  The movement control unit 111 flies over the object while controlling the drone 2 to a predetermined flight posture in the object position measurement mode. The predetermined flight postures are the first posture and the second posture in which the flight postures of the drone 2 are mirror-symmetric with each other. FIG. 3 is a diagram illustrating the first posture and the second posture. As shown in FIG. 3, the first posture and the second posture are flight postures that are mirror-symmetric with each other when a plane parallel to the vertical direction is a mirror plane. In other words, the first posture and the second posture are flight postures having the same posture angle and different azimuth angles by 180 °.

  The movement control unit 111 controls the first flight control for flying the drone 2 while controlling the flight posture of the drone 2 to the first posture, and the flight of the drone 2 while controlling the flight posture of the drone 2 to the second posture. The second flight control is executed in order. More specifically, the movement control unit 111 acquires the position of the object in the captured image from the object recognition unit 110 at regular intervals. Then, as the first flight control, the movement control unit 111 controls each motor 6 so that the position of the object is at the center of the captured image (imaging range) while controlling the flight posture of the drone 2 to the first posture. Control the drive. Next, as the second flight control, the movement control unit 111 controls each motor so that the position of the object becomes the center of the captured image (imaging range) while controlling the flight posture of the drone 2 to the second posture. 6 is controlled.

When the flight posture of the drone 2 is the first posture (during the first flight control), the target object position acquisition unit 112 is centered on the captured image (imaging range) P ₁ of the imaging device 1. The position information (hereinafter referred to as “first position information”) (X _1, Y ₁ ) of the drone 2 at a certain time is acquired from the self-position acquisition unit 7.
In addition, when the flying posture of the drone 2 is the second posture (during the second flight control), the target object position acquisition unit 112 is the center of the captured image (imaging range) P2 of the imaging device 1 The position information of the drone 2 (hereinafter referred to as “second position information”) (X _2, Y ₂ ) is acquired from the self-position acquisition unit 7.

  The object position acquisition unit 112 outputs the first position information and the second position information to the object position calculation unit 113.

The object position calculation unit 113 calculates an average value of the first position information and the second position information, and sets the calculated average value as the position of the object. Specifically, when the first position information is (X _1, Y ₁ ) and the second position information is (X _2, Y ₂ ), the object position calculation unit 113 calculates the object position. The position is set to ((X ₁ + X ₂ ) / 2 _, (Y ₁ + Y ₂ ) / 2). Thus, the object position calculation unit 113 can accurately measure the position of the object without using a conventional posture control mechanism.

  Next, the flow of operation in the object position measurement mode in the control unit 11 according to the present invention will be described. FIG. 4 is a flowchart of the operation in the object position measurement mode in the control unit 11 according to the embodiment of the present invention.

  The control unit 11 causes the drone 2 to fly over the object while controlling the flight posture of the drone 2 to the first posture based on the flight posture information from the posture detection unit 8. More specifically, the control unit 11 controls the driving of each motor 6 so that the position of the object is at the center of the captured image while controlling the flight posture of the drone 2 to the first posture. Flight control is executed (step S101).

The control unit 11 determines whether or not the position of the object is within a predetermined range including the center position of the captured image (imaging range) while executing the first flight control (step S102). When the control unit 11 determines that the position of the object is within a predetermined range including the center of the captured image while executing the first flight control, the position information of the drone 2 is set to the first position information. _(X 1, _{Y 1)} obtained from the self-position acquisition unit 7 as (step S103).
On the other hand, if the control unit 11 determines in step S102 that the position of the object does not exist within a predetermined range including the center position of the captured image (imaging range), the control unit 11 continues the first flight control.

  When the first position information is acquired, the control unit 11 executes the second flight control. In other words, the control unit 11 controls each motor 6 so that the position of the object becomes the center of the captured image while controlling the flight posture of the drone 2 to the second posture that is mirror-symmetrical with the first posture. Is controlled (step S104).

The control unit 11 determines whether or not the position of the object is within a predetermined range including the center position of the captured image (imaging range) while executing the second flight control (step S105). If the control unit 11 determines that the position of the target object is within a predetermined range including the center of the captured image while executing the second flight control, the position information of the drone 2 is set to the second position information. Obtained as (X _2, Y ₂ ) from the self-position obtaining unit 7 (step S106).
On the other hand, if it is determined in step S105 that the position of the object does not exist within a predetermined range including the center position of the captured image (imaging range), the control unit 11 continues the second flight control.

The control unit 11 calculates an average value of the coordinates of the first position information (X _1, Y ₁ ) and the second position information (X _2, Y ₂ ), and calculates the calculated average value ((X ₁ + X ₂ ) / 2 _, (Y ₁ + Y ₂ ) / 2) is positioned on the object (step S107).

Next, the function and effect according to this embodiment will be described.
FIG. 5 is a diagram for explaining problems of a conventional method for measuring the position of an object. In the conventional position measurement method, the vertical position of the drone is imaged by an imaging device, and the position of the target is measured by setting the position of the drone when the target is at the center of the captured image as the position of the target. To do.

  However, the position of the drone becomes the position of the target object only in an ideal case where the imaging device is attached to the drone so that the vertically lower side of the drone can be photographed. As shown in (), the mounting position of the imaging device with respect to the drone is displaced. Further, when there is a disturbance (such as a gust of wind) to the drone, as shown in FIG. 5 (b), it is necessary to photograph an object that is vertically below the drone while controlling the drone to a predetermined attitude angle. . Therefore, when there is a disturbance to the drone (such as a gust of wind), the drone's posture deviates from the horizontal state.

  As described above, in the conventional position measurement method, the displacement of the mounting position of the imaging device with respect to the drone or the displacement of the drone posture occurs, and even if there is an object at the center of the captured image, the drone actually There is a case where an object does not exist vertically below. As a result, the position of the drone and the position of the target object may be different, and the position of the target object may not be accurately measured.

  On the other hand, in the position measurement method according to the present embodiment, the object is at the center of the imaging range of the imaging apparatus 1 in the first attitude and the second attitude in which the attitude of the drone 2 is mirror-symmetrical with each other. Each position information of the drone 2 is acquired. Then, based on the position information of the drone 2 obtained in the first posture and the second posture, the position information of the object is calculated. Thereby, in this embodiment, the shift | offset | difference of the attachment position of the imaging device 1 with respect to the drone 2 and the shift | offset | difference of the attitude | position of the drone 2 can be negated, and the positional information on a target object can be measured correctly.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

(Modification 1) In the above embodiment, the position measuring device A measures the position of the object existing below the drone 2, but the present invention is not limited to this. For example, the position measuring device A may measure the position of the object existing above the drone 2 or may measure the position of the object in the left-right direction of the drone 2. Therefore, in order to measure the position of an object existing above, the imaging device 1 attaches the object existing above the drone 2 to the drone 2 so as to be able to image, and determines the position of the object existing in the left-right direction. In order to measure, the imaging device 1 is attached to the drone 2 so as to be able to image an object existing in the left-right direction of the drone 2.

(Modification 2) In the embodiment described above, two coordinates of the X coordinate and the Y coordinate of the global coordinate are obtained as the position of the object, but the present invention is not limited to this. For example, at least one of the X coordinate and the Y coordinate may be obtained as the position of the object.

(Modification 3) In the above embodiment, the start or end of the object position measurement mode in the control device 4 may be controlled from the remote control device of the drone 2. This remote operation device is operated by a user, and transmits and receives information by wireless communication with the control device 4. Therefore, the user can control the start or end of the object position measurement mode by operating the remote control device.

(Modification 4) In the above embodiment, the case where the object position acquisition unit 112 and the object position calculation unit 113 are provided in the control device 4 has been described, but the present invention is not limited to this. For example, the object position acquisition unit 112 and the object position calculation unit 113 or the object position calculation unit 113 may be provided in the remote operation device or the user communication terminal.

(Modification 5) In the above embodiment, the position of the object is measured in real time, but the present invention is not limited to this. For example, the control device 4 uses the captured image from the imaging device 1 and the position information of the drone 2 from the self-position acquisition unit 7 in each of the first posture and the second posture in the object position measurement mode. In association with each other, the information is stored in a storage unit in the own device at regular intervals. Then, the control device 4 uses the first information and the second information from the captured image from the imaging device 1 stored in the storage unit in the own device and the position information of the drone 2 from the own position acquisition unit 7. The position of the object may be obtained by extracting information. Further, the control device 4 obtains the captured image from the imaging device 1 and the position information of the drone 2 from the self-position acquisition unit 7 in each of the first posture and the second posture in the object position measurement mode. In association therewith, it may be transmitted to the remote control device or the user's communication terminal. In that case, in the remote control device or the user's communication terminal, the first information and the second information are extracted from the position information of the drone 2 from the self-position acquisition unit 7 to determine the position of the object. Ask.

  As described above, the position measuring apparatus A according to an embodiment of the present invention is an apparatus that measures the position of an object using a moving body (for example, an unmanned aerial vehicle or an underwater drone) equipped with the imaging device 1. It is. The position measurement apparatus A moves when the object is at the center of the imaging range of the imaging apparatus 1 in the first attitude and the second attitude in which the attitude of the moving body is mirror-symmetrical with each other. The object position acquisition unit 112 that acquires the position information of the body, and the position information of the object based on the position information of the moving body in the first posture and the second posture acquired by the object position acquisition unit 112 An object position calculation unit that calculates

  According to this configuration, the position of the object can be accurately measured without attaching the posture control mechanism to a small moving body such as a drone as well as a large moving body.

A Position measuring device 1 Imaging device 2 Drone (moving body)
3 Rotor unit 4 Control device 11 Control unit 110 Object recognition unit 111 Movement control unit 112 Object position acquisition unit (position acquisition unit)
113 Object position calculation unit (position calculation unit)

Claims (5)

A moving object,
An imaging device mounted on the moving body and imaging a target;
Position information of the moving object when the object is at the center of the imaging range of the imaging device in the first attitude and the second attitude in which the attitude of the moving object is mirror-symmetric with each other, respectively. A position acquisition unit to acquire;
A position calculation unit that calculates position information of the object based on position information of the moving body in the first posture and the second posture acquired by the position acquisition unit;
A position measuring device comprising:   The position calculation unit uses, as position information of the object, an average value of position information of the moving body in the first posture and the second posture acquired by the position acquisition unit. The position measuring device according to claim 1.   The position measurement apparatus according to claim 1, wherein the first posture and the second posture have the same posture angle and different azimuth angles from each other by 180 °.   The position measuring device according to any one of claims 1 to 3, wherein the imaging device photographs a lower part of the moving body. A position measurement method for measuring position information of an object using a moving body equipped with an imaging device for imaging the object,
Position information of the moving object when the object is at the center of the imaging range of the imaging device in the first attitude and the second attitude in which the attitude of the moving object is mirror-symmetric with each other, respectively. A position acquisition step to acquire;
A position calculating step for calculating position information of the object based on position information of the moving body in the first posture and the second posture acquired in the position acquiring step;
A position measurement method comprising:

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