JP2020003730A - Moving body, focus control method, program, and recording medium - Google Patents

Abstract

It is desirable to improve the focusing accuracy of a camera mounted on a gimbal. The moving body includes an imaging unit and a gimbal unit on which the imaging unit is mounted and corrects a shake of the imaging unit, wherein the gimbal unit acquires an angular velocity in at least one of three directions of the imaging unit. Then, a first time during which the state in which the angular velocity is equal to or less than the first threshold is measured is measured, and when the first time is equal to or greater than the second threshold, the imaging unit is instructed to execute the focus control. [Selection diagram] FIG.

Description

  The present disclosure relates to a moving object including a gimbal on which an imaging unit is mounted, a focus control method, a program, and a recording medium.

  2. Description of the Related Art Conventionally, in an imaging apparatus, in order to capture an image, focusing control is performed by a lens or a spherical mirror to control a position of a focal point at which incident light rays parallel to an optical axis are concentrated. Patent Literature 1 discloses an imaging device that drives a focusing lens at a low speed again when focusing becomes impossible due to auto focus (AF) control.

JP 2012-22238 A

  Patent Literature 1 does not consider that an imaging device is mounted on a gimbal. The gimbal corrects a shake of an object (for example, an imaging device) mounted on the gimbal. Therefore, the image pickup device mounted on the gimbal and the image pickup device not mounted on the gimbal have different shakes of the image pickup device. When the imaging device mounted on the gimbal performs a focusing operation, focusing may not be performed with high accuracy even if the technology described in Patent Document 1 is applied.

  In one aspect, a moving body including an imaging unit and a gimbal unit on which the imaging unit is mounted and corrects shake of the imaging unit, wherein the gimbal unit acquires an angular velocity in at least one of three directions of the imaging unit. Then, a first time during which the state in which the angular velocity is equal to or less than the first threshold is measured is measured, and when the first time is equal to or greater than the second threshold, the imaging unit is instructed to execute the focus control.

  When the first time is equal to or greater than the second threshold, the gimbal unit takes a second time to determine whether there is a change in the scene based on the subject imaged by the imaging unit, and determines whether there is a change in the scene. If it is determined that the scene has changed, the imaging unit may be instructed to execute focus control.

  When the first time is equal to or greater than the second threshold, the gimbal unit sequentially obtains evaluation values related to the contrast of the image captured by the imaging unit, and compares the evaluation value obtained last time with the evaluation value obtained this time. If the difference is greater than or equal to the third threshold, it may be determined that the scene has changed.

  The gimbal unit may extend the second time when the acquired angular velocity is larger than a fourth threshold larger than the first threshold.

  The imaging unit may capture a moving image. The gimbal unit may instruct the imaging unit to perform focusing control while continuously changing the focus position.

  The gimbal unit may acquire the information of the imaging operation for imaging the image by the imaging unit, and may acquire the angular velocity when the information of the imaging operation is acquired.

  The moving body may further include a grip portion gripped by the user.

  The moving object may further include a control unit that controls flight of the moving object.

  In one aspect, there is provided a focusing control method for a moving object including an imaging unit and a gimbal unit on which the imaging unit is mounted and corrects shake of the imaging unit, wherein an angular velocity of at least one of the imaging unit in three axial directions is determined. Acquiring, measuring a first time during which the state in which the angular velocity is equal to or less than the first threshold is continued, and executing focus control of the imaging unit when the first time is equal to or greater than the second threshold. And indicating.

  When the first time is equal to or greater than the second threshold, the focusing control method takes a second time for determining whether there is a change in the scene based on the subject imaged by the imaging unit, and The step of determining the presence or absence may be further included. The step of instructing execution of the focus control may instruct execution of the focus control when it is determined that the scene has changed.

  The step of determining the presence or absence of a change in the scene includes, when the first time is equal to or greater than a second threshold, sequentially obtaining evaluation values relating to the contrast of an image captured by the imaging unit; And determining that the scene has changed if the difference between the current value and the evaluation value obtained this time is equal to or greater than a third threshold value.

  The focusing control method may further include extending the second time when the obtained angular velocity is larger than a fourth threshold larger than the first threshold.

  The focusing control method may further include a step of capturing a moving image. The step of instructing execution of the focus control may instruct the focus control to be performed while continuously changing the focus position.

  The step of acquiring the angular velocity may include a step of acquiring information on an imaging operation for capturing an image by the imaging unit, and a step of acquiring an angular velocity when the information on the imaging operation is acquired.

  In one aspect, a program acquires an angular velocity in at least one of three directions of the imaging unit for a moving object including an imaging unit and a gimbal unit on which the imaging unit is mounted and corrects shake of the imaging unit. Measuring a first time during which the state in which the angular velocity is equal to or less than the first threshold is continued, and instructing the imaging unit to execute focus control when the first time is equal to or greater than the second threshold. And a program for executing

  In one aspect, the recording medium acquires an angular velocity in at least one of three directions of the imaging unit to a moving body including the imaging unit and a gimbal unit on which the imaging unit is mounted and corrects shake of the imaging unit. Measuring a first time during which the state where the angular velocity is equal to or less than the first threshold is continued; and instructing the imaging unit to execute the focus control when the first time is equal to or greater than the second threshold. And a computer-readable recording medium on which a program for executing the steps is recorded.

  Note that the above summary of the present invention does not list all of the features of the present disclosure. Further, a sub-combination of these feature groups can also be an invention.

FIG. 2 is a perspective view illustrating an appearance of the gimbal camera device according to the embodiment. Block diagram showing the hardware configuration of the gimbal camera device A timing chart showing a change in a signal of each part of the gimbal camera device in the first operation example. A graph showing a change in a contrast AF evaluation value corresponding to a focus lens position. Flowchart showing continuous autofocus operation procedure A diagram showing a transition of a degree of focus of a captured image when capturing an image by changing a scene 4 is a timing chart showing a change in a signal of each unit of the gimbal camera device in the second operation example. Flowchart showing continuous autofocus operation procedure A perspective view showing the appearance of another gimbal camera device. Perspective view showing the appearance of an unmanned aerial vehicle equipped with a gimbal

  Hereinafter, the present disclosure will be described through embodiments of the present invention, but the following embodiments do not limit the invention according to the claims. Not all combinations of the features described in the embodiments are necessarily essential to the solution of the invention.

  The claims, specification, drawings, and abstract include subject matter protected by copyright. The copyright owner will not object to any person's reproduction of these documents, as indicated in the JPO file or record. However, in all other cases, all copyrights are reserved.

  In the following embodiments, a gimbal camera device that captures an image while holding it in a hand will be exemplified as a moving object. The gimbal camera device may be a gimbal camera device mounted on an unmanned aerial vehicle. In the focusing control method, the operation of the moving body is specified. The recording medium stores a program (for example, a program that causes a moving object to execute various processes).

  FIG. 1 is a perspective view illustrating an appearance of a gimbal camera device 10 according to the embodiment. The gimbal camera device 10 has a configuration including a gimbal 20, a camera 30, a monitor 50, and a device main body 60.

  The apparatus main body 60 is, for example, a member formed in a substantially columnar shape. The gimbal 20 is detachably mounted on the upper end of the apparatus main body 60. A mounting portion 63 to which the monitor 50 can be mounted is provided on the left side surface of the apparatus main body 60 in the drawing. On the right side of the apparatus main body 60, a female screw portion (not shown) to be attached to a tripod is formed.

  An operation surface 610 that is inclined forward is formed on the upper front surface of the apparatus main body 60. Various buttons and indicators 614 are arranged on the operation surface 610. The various buttons include a shutter button 611, a recording button 612, and an operation button 613. The lower center part of the apparatus main body 60 is formed in a grip part 620 which is gripped by the hand of the photographer.

  The gimbal 20 has a camera 30 mounted thereon and corrects a shake of the camera 30. The gimbal 20 variably supports the attitude of the camera 30. The gimbal 20 is an example of a gimbal unit. The gimbal 20 is attached to an attachment part 210 provided at the upper end of the apparatus main body 60. The mounting portion 210 is provided with a release button 211 for releasing the engagement between the gimbal 20 and the apparatus main body 60.

  The gimbal 20 includes a yaw axis motor 215, a roll axis motor 216, and a pitch axis motor 217. The yaw axis motor 215 is disposed at the upper end of the apparatus main body 60. The roll axis motor 216 is attached to the yaw axis motor 215 via the arm member 221. The pitch axis motor 217 is attached to the roll axis motor 216 via the arm member 222. The gimbal 20 drives the yaw axis motor 215, the roll axis motor 216, and the pitch axis motor 217, and moves the camera 30 in three directions of the yaw axis, the roll axis, and the pitch axis so that the direction of the camera 30 with respect to the subject does not fluctuate. It is rotatably supported.

  The camera 30 has a built-in imaging unit capable of imaging a subject, and has a housing 311 rotatably supported by a roll axis motor 216 and a pitch axis motor 217.

  The monitor 50 displays an image (for example, a still image or a moving image) captured by the camera 30. The monitor 50 may be attached as an option so as to be freely exchangeable. Here, a portable terminal (smartphone) that can wirelessly communicate with the camera 30 is used as the monitor 50. Note that the monitor 50 may not be provided.

  FIG. 2 is a block diagram illustrating a hardware configuration of the gimbal camera device 10. The gimbal camera device 10 has a configuration including a gimbal 20, a camera 30, and a monitor 50. The gimbal 20 has a gimbal control unit 21, a memory 22, an inertial measurement device 23, an angle detector 24, a yaw axis rotation mechanism 25, a pitch axis rotation mechanism 26, a roll axis rotation mechanism 27, an interface 28, and an operation unit 29.

  The gimbal control unit 21 controls the operation of each unit of the gimbal 20. For example, the gimbal control unit 21 may calculate a contrast AF evaluation value for determining a focus state based on an image captured by the camera 30. The function of the gimbal control unit 21 is realized by, for example, the processor executing a program stored in the memory 22.

  The memory 22 stores various data, information, a program executable by the gimbal control unit 21, image data of an image captured by the camera 30, and the like.

  The inertial measurement device 23 detects and acquires acceleration in the three axial directions of the gimbal camera device 10 in front and rear, left and right, and up and down, and angular velocities in three axial directions of a pitch axis, a roll axis, and a yaw axis. The inertial measurement device 23 may include a Hall sensor that detects a change in magnetic flux, and a gyro sensor that detects the attitude (tilt) of the gimbal camera device 10. Note that an acceleration sensor may be used instead of the inertial measurement device 23.

  The angle detector 24 detects, for example, angles in three axial directions of a pitch axis, a roll axis, and a yaw axis as directions of the gimbal camera device 10. The detected angle may be an angle with respect to the reference direction.

  Therefore, the gimbal control unit 21 may calculate and acquire the angular velocity based on the angle detected by the angle detector 24 and the time required for changing the angle. Further, the gimbal control unit 21 may acquire the angular velocity from the inertial measurement device 23.

  The yaw axis rotation mechanism 25 includes a yaw axis motor 215 that drives the camera 30 in the yaw axis direction. The pitch axis rotation mechanism 26 includes a pitch axis motor 217 that drives the camera 30 in the pitch axis direction. The roll axis rotation mechanism 27 includes a roll axis motor 216 that drives the camera 30 in the roll axis direction.

  The interface 28 can connect external devices such as an input device, an output device, and a recording medium. The operation unit 29 includes various buttons arranged on the operation surface 610.

  The camera 30 includes an imaging control unit 31, a lens control unit 32, a memory 33, an imaging element 34, lens driving units 35 and 36, a focus lens 37, and a zoom lens 38.

  The imaging control unit 31 drives the imaging device 34 to perform an imaging operation in accordance with an imaging instruction from the gimbal 20. The imaging control unit 31 processes image data of an image captured by the imaging element 34 and stores the processed data in the memory 33. The processing of the image data may include calculation of a contrast AF evaluation value for determining a focused state and various image processing. The imaging control unit 31 may send an instruction to change the zoom magnification or perform automatic exposure to the lens control unit 32.

  The lens controller 32 moves the lens position of the focus lens 37 in the optical axis direction to adjust the focus, and changes the lens position of the zoom lens 38 in the optical axis direction to change the zoom magnification. The lens driving unit 36 is controlled. The lens control unit 32 performs a focusing operation in accordance with a focusing control instruction from the gimbal 20. The function of the lens control unit 32 is realized by, for example, a processor executing a program stored in the memory 33. The lens drive unit 35 and the lens drive unit 36 each include a drive motor (not shown).

  The focus lens 37 collects light from the subject and forms an optical image on the imaging surface of the imaging device 34. The zoom lens 38 has a lens barrel (not shown) that houses the lens, and expands and contracts the lens barrel in the front-rear direction when performing a zooming operation. Note that the zoom lens 38 need not be provided.

  The memory 33 holds various data, information, and programs. This is a storage medium for storing camera parameters, image data, and the like. The memory 33 stores, for example, shutter speed, F-number, ISO sensitivity, and the like as camera parameters.

  The imaging element 34 photoelectrically converts the optical image formed on the imaging surface into an electric signal and outputs the electric signal as an image signal. As the image pickup device, a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor may be used.

  The monitor 50 may be a smartphone having a touch panel on the front. The monitor is not limited to a smartphone, and may be a display unit having a liquid crystal display, an organic EL (Electro Luminescence), or the like.

  The camera 30 and the monitor 50 can communicate with each other by wired communication (for example, USB communication) or wireless communication (for example, wireless LAN, Bluetooth (registered trademark), short-range communication, or public wireless line). The image captured by the camera 30 may be displayed on the monitor 50 in real time.

  Next, the operation of the gimbal camera device 10 will be described.

  Here, a case where the gimbal camera apparatus 10 performs imaging while changing a scene while performing continuous autofocus (CAF) control is shown. In the continuous automatic focus control, the focus control is performed while continuously changing the focus position.

  In general, when the photographer moves the camera largely, the subject also fluctuates greatly (blurs), so that it is difficult to focus. If the AF (auto focus) operation is performed while the camera itself is moving, the subject cannot be found, and only the focus lens operates. As a result, the image quality of the image tends to deteriorate.

  In the present embodiment, the gimbal camera device 10 determines whether or not the camera 30 is largely moving based on the movement of the gimbal 20. For example, when the gimbal 20 moves beyond the threshold, the gimbal camera device 10 stops the AF operation of the camera 30 and waits until the movement of the gimbal falls below the threshold (the movement of the camera is stable) before starting the AF operation. (Resume).

(First operation example)
As a first operation example, a case where the movement of the gimbal is relatively slow is shown. The first operation example is, for example, gently moving the gimbal camera device 10 held by the imager, gently changing the direction of the gimbal camera device 10, or holding the gimbal camera device 10 and riding on a vehicle or the like. It is assumed that a large vibration occurs.

  FIG. 3 is a timing chart showing changes in signals of various parts of the gimbal camera device 10 in the first operation example. The vertical axis represents the angular velocity ΔAngle of the yaw axis, the pitch axis, and the low axis. The horizontal axis represents time. The angular velocity ΔAngle may be measured by the inertial measurement device 23. Further, the angular velocity ΔAngle may be calculated based on the angle detected by the angle detector 24.

  When the gimbal camera device 10 moves to change the scene, the gimbal 20 operates to suppress the rotational force (angular acceleration) applied to the yaw axis, the pitch axis, and the low axis so that the captured image does not shake. In this case, the angular velocities of the yaw axis, the pitch axis, and the low axis fluctuate (vibrate) according to the external force (eg, camera shake) applied to the gimbal camera device 10 and the driving of each motor of the gimbal 20. For example, since the external force applied to the gimbal camera device 10 converges over time, the vibration of the angular velocity converges over time. While the angular velocity fluctuates greatly (a state in which the captured image is slightly vibrating), it is not suitable for performing the AF operation. Therefore, the gimbal 20 suspends the CAF operation during this period, and starts (resumes) the CAF operation after the change in the angular velocity has converged.

  The gimbal 20 is set with a first threshold value TH1 for determining whether or not the variation of the angular velocity is converging. The first threshold value TH1 is a value indicating a range in which the AF operation and the CAF operation are allowed. The setting of the first threshold value TH1 may be performed by writing to the memory 22 at the time of factory shipment or the like. The setting of the first threshold value TH1 may be arbitrarily set by, for example, receiving a user operation via the operation unit 29. That is, the first threshold value TH1 may be a fixed value or a variable value.

  As shown in FIG. 3, in the vibration period t1, the angular velocity signal g1 fluctuates greatly as the scene change exceeds the first threshold value TH1. The gimbal controller 21 detects the timing (time) t11 at which the variation of the angular velocity signal g1 starts to converge and the angular velocity signal g1 falls within the first threshold value TH1 via the inertial measurement device 23 and the like.

  The gimbal control unit 21 waits until a period during which the angular velocity signal g1 falls within the first threshold value TH1 reaches a standby period t2. If the angular velocity signal g1 again exceeds the first threshold value TH1 during the waiting period t2, the gimbal control unit 21 waits until the angular velocity signal g1 falls within the first threshold value TH1 again. The waiting period t2 is, for example, 500 msec. The standby period can also be referred to as a gimbal stabilization period in which the vibration of the gimbal 20 is stabilized.

  When the waiting period t2 ends, the gimbal control unit 21 sets a status check flag (status check ON), and starts (resumes) the CAF operation based on the contrast AF evaluation value obtained from the camera 30 in the scene determination period t3. ) Judge whether it can be done. The scene determination period t3 is, for example, one second. In the scene determination, the contrast AF evaluation value is referred to. Information on the state check flag may be held in the memory 22.

  The contrast AF evaluation value may be a value obtained by calculating a frequency component of a captured image and calculating the low frequency component. When the contrast AF evaluation value is calculated, an operation of shifting the focus lens position is performed. For this reason, the gimbal control unit 21 needs some time to evaluate the focused state by the contrast AF method. When the captured image is slightly vibrating, a waiting time is required. The evaluation of the in-focus state may be performed by the phase difference AF method or the image plane phase difference AF method.

  The gimbal control unit 21 determines whether or not the contrast AF evaluation value is within a predetermined range during the scene determination period t3 (scene determination). This predetermined range is set with reference to the reference value of the contrast AF evaluation value that is determined to be in focus, and is, for example, within a threshold th3 (for example, within ± 15%) from the reference value (see FIG. 4). This reference value may be, for example, a contrast AF evaluation value derived immediately before (previous time). That is, when the difference between the currently calculated contrast AF evaluation value and the previously calculated contrast AF evaluation value is within the threshold th3 (within ± 15%), the gimbal control unit 21 determines that the scene has not changed. You may decide. Therefore, for example, when the subject is in focus at the time of calculating the contrast AF evaluation value last time, it is possible to determine that the subject is in focus without any change even at the time of the current calculation.

  After the scene determination period t3 has elapsed, the gimbal control unit 21 determines not to perform the CAF operation when the contrast AF evaluation value is within the threshold th3 as a result of the scene determination in the determination period t4 (CAF OFF). This is because it is possible to determine that the scene is in focus because the scene has not changed. On the other hand, if the contrast AF evaluation value is out of the predetermined range, the gimbal control unit 21 determines to perform the CAF operation (CAF ON). Because the scene has changed, it can be determined that the subject is not in focus, and it can be determined that the focusing operation is necessary.

  Note that the gimbal control unit 21 may acquire a determination result as to whether or not the change is a scene change. In this case, the imaging control unit 31 calculates a contrast AF evaluation value based on the captured image, the gimbal control unit 21 receives the contrast AF evaluation value from the camera 30 (imaging control unit 31), and sets the contrast AF evaluation value to a threshold. It may be determined whether or not the change of the scene deviates from within th3. The gimbal control unit 21 receives the captured image from the camera 30 (imaging control unit 31), calculates a contrast AF evaluation value based on the captured image, and determines whether a scene change has occurred based on the contrast AF evaluation value. Good. In addition, the imaging control unit 31 of the camera 30 calculates a contrast AF evaluation value based on the captured image, determines whether or not there is a change in the scene based on the contrast AF evaluation value, and compares the determination result with the gimbal 20 (gimbal control unit). 21).

  As described above, the gimbal control unit 21 determines that the time during which the angular velocity ΔAngle falls within the first threshold value TH1 (an example of the first time) has passed the standby period t2 (an example of the case where the time is equal to or greater than the second threshold value) ), The contrast AF evaluation value (evaluation value related to the contrast of the image) of the image captured by the camera 30 may be sequentially acquired (for example, calculated). When the contrast AF evaluation value is out of the predetermined range (within the threshold th3 (for example, within ± 15%)), the gimbal control unit 21 may determine that the scene is out of focus due to a change in the scene. For example, if the difference between the previously obtained contrast AF evaluation value and the currently obtained contrast AF evaluation value is not within the threshold th3 (an example of a third threshold or more), the gimbal control unit 21 enters the out-of-focus state. It may be determined that such a scene change has occurred.

  For example, when the subject captured by the camera 30 changes from a white subject to a black subject, the contrast AF evaluation value obtained when the previously calculated white subject is captured and the black subject calculated this time are captured. In this case, the difference from the contrast AF evaluation value is not within the threshold th3. In this case, the gimbal camera device 10 can determine that the gimbal camera device 10 has moved, the scene has changed, and the image captured by the camera 30 has become out of focus.

  FIG. 4 is a graph showing a change in the contrast AF evaluation value corresponding to the focus lens position. The vertical axis of the graph represents the contrast AF evaluation value, and the horizontal axis represents the focus lens position. If the calculated contrast AF evaluation value is within a threshold th3 (for example, within ± 15%) with respect to a reference value (a peak value when it is assumed that the subject is in focus), the gimbal control unit 21 sets the focus It may be determined that the lens position is in focus. The comparison between the contrast AF evaluation value and the reference value may be performed by the imaging control unit 31.

  FIG. 5 is a flowchart showing a continuous automatic focusing operation procedure. This operation may be executed when the photographer (user) presses the operation button 613 and the gimbal control unit 21 receives this pressing operation via the operation unit 29. This operation may be performed when the inertial measurement device 23 or the like detects a shake after the start of the CAF operation.

  When the imaging is started, the gimbal control unit 21 turns off the CAF operation and does not perform the CAF operation (S1).

  The gimbal controller 21 acquires the yaw axis, pitch axis, and low axis angular velocities ΔAngle by the inertial measurement device 23. The gimbal control unit 21 determines whether or not the angular velocity of the gimbal 20, that is, the angular velocity ΔAngle of the yaw axis, the pitch axis, and the low axis is equal to or less than the first threshold value TH1 (S2). In this case, the gimbal control unit 21 may determine whether at least one of the yaw axis, pitch axis, and low axis angular velocities ΔAngle is equal to or less than the first threshold value TH1. If it exceeds the first threshold TH1, the gimbal control unit 21 waits until the angular velocity ΔAngle falls below the first threshold TH1.

  When the angular velocity ΔAngle becomes equal to or less than the first threshold value TH1, the gimbal control unit 21 measures a time during which the angular velocity ΔAngle continues to be equal to or less than the first threshold value TH1. The gimbal control unit 21 determines whether or not the angular velocity ΔAngle is equal to or less than the first threshold value TH1 during the standby period t2, that is, whether or not the vibration has exceeded the first threshold value TH1 (S3). If the value exceeds the first threshold value TH1, the gimbal control unit 21 returns to the process of S2.

  If the angular velocity ΔAngle falls below the first threshold value TH1 during the standby period t2, the gimbal control unit 21 calculates a contrast AF evaluation value during the scene determination period t3 (S4).

  The gimbal control unit 21 determines whether the calculated contrast AF evaluation value falls within a predetermined range (for example, a change in the contrast AF evaluation value is within ± 15% of the reference value) (S5). When the contrast AF evaluation value is within the predetermined range, the gimbal control unit 21 determines that the CAF operation is not performed, and returns to the process of S2.

  On the other hand, when the contrast AF evaluation value is out of the predetermined range in S5, the gimbal control unit 21 determines whether or not the angular velocity ΔAngle falls within the first threshold value TH1 in the determination period t4 (S6). When the angular velocity ΔAngle again exceeds the first threshold value TH1, the gimbal control unit 21 returns to the processing of S1. On the other hand, when the angular velocity ΔAngle is equal to or less than the first threshold value TH1, the gimbal control unit 21 causes the camera 30 to start (restart) the CAF operation (S7). Thereafter, the gimbal control unit 21 ends the operation.

  Note that the process of checking the contrast AF evaluation value in S5 (the process of determining the presence or absence of a scene change) may be omitted.

  As described above, the gimbal 20 acquires the angular velocity (angular velocity ΔAngle) of the camera 30 in at least one of the three axis directions including the yaw axis, the pitch axis, and the low axis. The gimbal 20 measures a waiting period t2 (an example of a first time) in which a state in which the angular velocity ΔAngle is equal to or less than a first threshold TH1 (an example of a first threshold) continues. When the waiting period t2 has elapsed, the gimbal 20 instructs the camera 30 to execute the CAF operation.

  For example, if the camera 30 is vibrating because the gimbal camera device 10 is moving, the angular velocity ΔAngle becomes equal to or higher than a certain value, and the gimbal camera device 10 does not perform the CAF operation. Further, even if the angular velocity ΔAngle is equal to or less than the first threshold value TH1 and the shake of the camera 30 is reduced, the shake is corrected by the shake correction function so that the camera 30 shakes in the opposite direction to the actual shake direction. It takes a certain amount of time for the shake to stop. On the other hand, the gimbal camera apparatus 10 performs the CAF operation when the time during which the angular velocity ΔAngle becomes equal to or less than the first threshold value TH1 continues for the standby period t2 (constant time), whereby the camera using the gimbal 20 having the camera 30 mounted thereon. The CAF operation can be performed in consideration of the 30 shake correction. Therefore, the gimbal camera apparatus 10 waits for the CAF operation when the shake does not converge due to the shake correction of the camera 30, for example, and performs the CAF operation after the shake converges. Can be improved in focusing accuracy.

  When the time during which the angular velocity ΔAngle is equal to or less than the first threshold value TH1 is equal to or longer than the standby period t2, the gimbal 20 takes a scene determination period (an example of a second time period) to determine whether a scene change has occurred. You may decide. When it is determined that the scene has changed, the gimbal 20 may instruct the camera 30 to execute a CAF operation (focus control). Thus, if the scene changes to, for example, an out-of-focus state, the gimbal camera device 10 can perform a CAF operation to transition to the in-focus state.

  In addition, the gimbal control unit 21 may instruct the camera 30 to perform a CAF operation (focus control while continuously changing a focus position) when the camera 30 captures an image of a subject. When performing the CAF operation, the camera 30 can capture a moving image while focusing on the subject even if the subject moves.

  In addition, when the gimbal control unit 21 receives a press of the shutter button 611, the recording button 612, or the operation button 613 (an example of a case where information on an imaging operation for imaging an image is acquired), the gimbal control unit 21 acquires an angular velocity ΔAngle. May be. Accordingly, the gimbal camera device 10 can instruct the imaging at a timing according to the intention of the imager, and can start checking the degree of shake of the camera 30.

  In addition, since the gimbal camera device 10 includes the grip portion 620, the photographer can freely grip and move the gimbal camera device 10. Also in this case, the gimbal camera device 10 can perform the focusing operation in consideration of the shake of the camera 30, and can improve the focusing accuracy. Therefore, the gimbal camera device 10 can capture a high-quality image.

  FIG. 6 is a diagram showing the transition of the degree of focus of the captured image when the image is captured while changing the scene. Here, a quadrangular pyramid is shown as an example of a simple subject for easy understanding.

  The captured image p1 of the quadrangular pyramid obj is in focus immediately after the start of imaging or before a scene change during imaging. In this case, the gimbal control unit 21 instructs the camera 30 to execute the CAF operation. Thereafter, for example, when the user changes the direction of the camera 30, the camera 30 vibrates, and the CAF operation is interrupted. Further, in this case, the direction of the camera 30 with respect to the quadrangular pyramid obj changes, the subject to be imaged by the camera 30 changes, and the scene changes. When the in-focus state occurs due to the change in the scene, the captured images p2, p3, and p4 become blurred. When the vibration of the camera 30 converges and the change in the scene calms down, the gimbal control unit 21 resumes the CAF operation, and the captured image p5 returns to the focused state. Note that if the focused state is maintained even when the scene is changed, that is, if the contrast AF evaluation value is within a predetermined range before and after the scene change, the CAF operation may not be performed. Even in this case, if there is no scene change and the subject has not been changed, the in-focus state is maintained.

(Second operation example)
In the first operation example, the case where the gimbal camera device 10 is changed small (slowly) is shown. In the second operation example, the gimbal camera device 10 is changed largely (suddenly). In the second operation example, for example, the gimbal camera device 10 held by the photographer is suddenly moved, the direction of the gimbal camera device 10 is rapidly changed, or It is assumed that a sudden vibration is generated by traveling on a road that has not been driven.

  FIG. 7 is a timing chart showing changes in signals of various parts of the gimbal camera device 10 in the second operation example. The vertical axis represents the angular velocity ΔAngle of the yaw axis, the pitch axis, and the low axis. The horizontal axis represents time. The angular velocity ΔAngle may be measured by the inertial measurement device 23 or the like. Further, the angular velocity ΔAngle may be calculated based on the angle detected by the angle detector 24.

  In the second operation example, in addition to the first threshold value TH1 set for determining whether or not the vibration of the angular velocity is converging, the second threshold value TH2 for determining whether the angular velocity has greatly changed is set. Is set.

  In the vibration period t1, the signal g2 of the angular velocity exceeds the first threshold TH1 due to a change in the scene, and further exceeds the second threshold TH2 at a timing (time) t10, and fluctuates greatly. Thereafter, when the angular velocity signal g2 starts to converge, the gimbal control unit 21 detects, via the inertial measurement device 23 and the like, a timing t11 at which the angular velocity signal g2 falls within the first threshold TH1.

  The gimbal control unit 21 waits until a period during which the angular velocity signal g2 falls within the first threshold value TH1 reaches a standby period t2. If the angular velocity signal g2 again exceeds the first threshold value TH1 during the waiting period t2, the gimbal control unit 21 waits until the angular velocity signal g2 falls within the first threshold value TH1 again.

  When the waiting period t2 ends, the gimbal control unit 21 sets a status check flag (status check ON), and determines whether to start (restart) the CAF control based on the contrast AF evaluation value in the scene determination period t3. Judge. The gimbal control unit 21 extends the scene determination period t3 by the extension time ta compared to the first operation example because the angular velocity has exceeded the second threshold value TH2. For example, the scene determination period t3 is extended from 1 second in the first operation example to 1.5 seconds 1.5 times (extended time ta = 0.5 seconds). Accordingly, when the imaging direction of the camera 30 changes suddenly, the period until it is determined whether or not the camera is in focus can be extended in the scene determination period t3, so that the gimbal control unit 21 has sufficient time. The contrast AF evaluation value can be calculated. Therefore, when the camera 30 is rapidly moved (moved with a large acceleration), it is expected that it will take a longer time before the camera 30 returns to the reference position (reference direction). Focusing operation (for example, CAF operation or AF operation) can be started in consideration of time.

  The gimbal control unit 21 ends the scene determination period t3, and in the determination period t4, as a result of the determination based on the contrast AF evaluation value, the contrast AF evaluation value is within a predetermined range (for example, within a threshold th3 (for example, within ± 15%)). In this case, it is determined not to perform the CAF operation (CAF OFF). On the other hand, if the contrast AF evaluation value is out of the predetermined range, the gimbal control unit 21 determines that the CAF operation is started (restarted) assuming that the subject is out of focus (CAF ON).

  FIG. 8 is a flowchart showing a continuous automatic focusing operation procedure. FIG. 8 mainly describes a procedure different from that of FIG. 5 shown in the first operation example.

  When the angular velocity ΔAngle exceeds the first threshold value TH1 in S2, the gimbal control unit 21 determines whether the angular velocity ΔAngle greatly changes and exceeds the second threshold value TH2 (S2A). In this case, the gimbal control unit 21 may determine whether at least one of the yaw axis, pitch axis, and low axis angular velocities ΔAngle is greater than the second threshold value TH2. If the angular velocity ΔAngle is equal to or less than the second threshold value TH2, the gimbal control unit 21 returns to the processing of S2. That is, since the angular velocity ΔAngle is not a very large value here, the gimbal control unit 21 can determine that the time required for the direction of the camera 30 to return to the reference direction is short. Therefore, the gimbal control unit 21 does not extend the scene determination period t3.

  On the other hand, when the angular velocity ΔAngle exceeds the second threshold value TH2, the gimbal control unit 21 extends the scene determination period t3 (S2B). Thereafter, the gimbal control unit 21 returns to the processing of S3. Other processes are the same as those in the first operation example. Note that the scene determination period t3 is extended only once. The extension of the scene determination period t3 may be performed a plurality of times.

  Thus, in the second operation example, the gimbal 20 may extend the scene determination period t3 when the angular velocity ΔAngle exceeds the first threshold value TH1 and is larger than the second threshold value TH2 (an example of a fourth threshold value). .

  When the camera 30 shakes greatly (for example, when the acceleration is large), the camera 30 slowly returns to the reference position thereafter, so that it takes a long time until the vibration of the camera 30 stops (returns to the reference position). That is, there is a tendency that the time during which the in-focus state can be determined using the contrast AF evaluation value (for example, the scene determination period t3) becomes longer. Also in this case, the gimbal camera device 10 determines the presence or absence of the in-focus state in a state where the shake of the camera 30 is stabilized by extending the scene determination period t3. Therefore, even when the camera 30 is shaken, the accuracy of the focus state determination is improved.

  Note that the gimbal 20 may simply instruct the execution of the AF operation instead of the CAF operation when the standby period t2 has elapsed. Even in this case, the camera 30 can adjust the focus when capturing a subject as a still image.

(Other gimbal camera devices)
FIG. 9 is a perspective view showing the appearance of another gimbal camera device 10B. 9, the same components as those of the gimbal camera device 10 shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted or simplified.

  The gimbal camera device 10B has a configuration including a device main body 60B, a gimbal 20B, and a portable terminal 50B. The device main body 60B is, for example, a member formed in a substantially columnar shape. A gimbal 20B is detachably mounted on the upper end of the apparatus main body 60B. An operation surface 610 having an inclination is formed on an upper front surface of the apparatus main body 60B. Various buttons are arranged on the operation surface 610. The various buttons include a shutter button 611, a record button 612, and an operation button 613. The lower center part of the apparatus main body 60 is formed in a grip part 620 which is gripped by the hand of the photographer.

  The gimbal 20B is detachably attached to the upper end of the device main body 60b. The portable terminal 50B is attached to the gimbal 20B via the attachment part 315. The gimbal 20B variably supports the position and orientation of the portable terminal 50B attached to the attachment section 315.

  The gimbal 20B has a yaw axis motor 215, a roll axis motor 216, and a pitch axis motor 217. The yaw axis motor 215 is arranged at the upper end of the apparatus main body 60B. The roll axis motor 216 is attached to the yaw axis motor 215 via the arm member 221. The pitch axis motor 217 is attached to the roll axis motor 216 via an arm member. The gimbal 20B drives the yaw axis motor 215, the roll axis motor 216, and the pitch axis motor 217, and controls the yaw axis, the roll axis, and the The portable terminal 50B is rotatably supported in three axis directions of the pitch axis.

  The gimbal 20B and the portable terminal 50B can communicate with each other by wired communication (for example, USB communication) or wireless communication (for example, wireless LAN, Bluetooth (registered trademark), short-range communication, or public wireless line).

  The mobile terminal 50B may display an image captured by an imaging unit (not shown) included in the mobile terminal 50B in real time. Since the imaging unit of the mobile terminal 50B is mounted on the gimbal 20B, it is affected by the shake correction by the gimbal 20, as in the gimbal camera device 10. Also in this case, the gimbal camera device 10B can perform the focusing operation in consideration of the shake correction by the gimbal 20B similarly to the gimbal camera device 10, so that the focusing accuracy can be improved.

(Gimbal mounted on unmanned aircraft)
FIG. 10 is a perspective view illustrating an appearance of the unmanned aerial vehicle 100 on which the gimbal 200 is mounted. The unmanned aerial vehicle 100 is an example of a moving object. The unmanned aerial vehicle 100 is configured to include a UAV main body 102, a gimbal 200, an imaging unit 220, a plurality of imaging units 230, and a UAV control unit (not shown).

  The UAV main body 102 includes a plurality of rotors (propellers). The UAV body 102 causes the unmanned aerial vehicle 100 to fly by controlling the rotation of a plurality of rotors. The UAV body 102 causes the unmanned aerial vehicle 100 to fly using, for example, four rotors. The number of rotors is not limited to four. Further, the unmanned aerial vehicle 100 may be a fixed wing aircraft having no rotary wing.

  The gimbal 200 may rotatably support the imaging unit 220 about the yaw axis, the pitch axis, and the roll axis. The gimbal 200 may change the imaging direction of the imaging unit 220 by rotating the imaging unit 220 around at least one of the yaw axis, the pitch axis, and the roll axis.

  The imaging unit 220 is an imaging camera that captures an image of a subject included in a desired imaging range (e.g., an aerial image of the sky, scenery such as a mountain or river, or a building on the ground).

  The plurality of imaging units 230 are sensing cameras that image the periphery of the unmanned aerial vehicle 100 to control the flight of the unmanned aerial vehicle 100.

  UAV control section 110 controls the flight of unmanned aerial vehicle 100. The UAV control unit 110 controls the gimbal 200, the rotary wing mechanism (not shown), the imaging unit 220, and the imaging unit 230. The UAV control unit may acquire posture information indicating the state of the posture of the imaging unit 220 from the gimbal 200, for example, as information indicating the imaging direction of the imaging unit 220. The attitude information of the imaging unit 220 may indicate a rotation angle of the pitch axis and the yaw axis of the gimbal 200 from the reference rotation angle. The UAV control unit 110 may control the imaging mechanism of the imaging unit 220 supported by the gimbal 200 by controlling the rotation mechanism of the gimbal 200.

  As described above, since the imaging unit 220 is mounted on the gimbal 200, the imaging unit 220 is affected by shake correction by the gimbal 200, similarly to the gimbal camera device 10. Also in this case, similarly to the gimbal camera devices 10 and 10B, the unmanned aerial vehicle 100 can perform the focusing operation in consideration of the shake correction by the gimbal 200, so that the focusing accuracy can be improved. In addition, the unmanned aerial vehicle 100 can improve the focusing accuracy of the imaging unit 220 while correcting the shake of the imaging unit 220 by the gimbal 200 even during the flight, for example, even when affected by airflow. Therefore, the unmanned aerial vehicle 100 can take a high-quality image by directing the imaging direction of the imaging unit 220 to an arbitrary direction while flying in a free direction.

  As described above, the present disclosure has been described using the embodiments, but the technical scope of the present disclosure is not limited to the scope described in the above-described embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the embodiments described above. It is also apparent from the description of the claims that embodiments with such changes or improvements can be included in the technical scope of the present disclosure.

  The execution order of each processing such as operation, procedure, step, and stage in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before”, “before”. And the like, and can be realized in any order as long as the output of the previous process is not used in the subsequent process. Even if the operation flow in the claims, the specification, and the drawings is described using “first”, “next”, and the like for convenience, it means that it is essential to perform the operations in this order. is not.

  Further, the present disclosure supplies a program for realizing the functions of the device of the above-described embodiment to the device via a network or various storage media, and reads and executes a program in a computer in the device, and stores the program. The recording medium used is also applicable.

10, 10B Gimbal camera device 20, 20B, 200 Gimbal 21 Gimbal control unit 22 Memory 23 Inertial measurement device 24 Angle detector 25 Yaw axis rotation mechanism 26 Pitch axis rotation mechanism 27 Roll axis rotation mechanism 28 Interface 29 Operation unit 30 Camera 31 Imaging Control unit 32 Lens control unit 33 Memory 34 Image sensor 35, 36 Lens driving unit 37 Focus lens 38 Zoom lens 50 Monitor 50B Portable terminal 60 Device main body 63 Mounting unit 100 Unmanned aerial vehicle 102 UAV main body 210 Mounting unit 211 Release button 215 Yaw axis motor 216 Roll axis motor 217 Pitch axis motor 221, 222 Arm member 220, 230 Imaging section 311 Housing 315 Mounting section 330 Grip section 610 Operation surface 611 Shutter button 612 Record button 613 Operation button 614 Caterer 620 Gripping part obj Square pyramids p1 to p6

Claims (16)

A moving body including an imaging unit and a gimbal unit that is mounted with the imaging unit and corrects a shake of the imaging unit,
The gimbal part is
Acquiring an angular velocity in at least one of three directions of the imaging unit;
Measuring a first time during which the state in which the angular velocity is equal to or less than a first threshold value,
When the first time is equal to or greater than a second threshold, instructs the imaging unit to execute focus control;
Moving body. The gimbal part is
If the first time is equal to or greater than the second threshold, the second imaging unit takes a second time to determine whether there is a change in the scene based on the subject imaged by the imaging unit, and determines whether there is a change in the scene. Judge,
If it is determined that the scene has changed, instruct the imaging unit to execute focus control,
The moving object according to claim 1. The gimbal part is
If the first time is equal to or greater than the second threshold, sequentially obtain evaluation values related to the contrast of an image captured by the imaging unit;
When the difference between the previously acquired evaluation value and the currently acquired evaluation value is equal to or greater than a third threshold, it is determined that the scene has changed.
The moving body according to claim 2. The gimbal unit extends the second time when the acquired angular velocity is larger than a fourth threshold larger than the first threshold.
The moving object according to claim 2. The imaging unit captures a moving image,
The gimbal unit instructs the imaging unit to perform the focusing control while continuously changing a focus position,
The moving body according to claim 1. The gimbal part is
Acquiring information of an imaging operation for imaging an image by the imaging unit,
When the information of the imaging operation is obtained, the angular velocity is obtained,
The moving body according to claim 1. Further comprising: a grip portion gripped by a user;
The moving object according to claim 1. A control unit that controls the flight of the moving object,
The moving object according to claim 1. An imaging unit, a focusing control method in a moving body including a gimbal unit mounted on the imaging unit and correcting the shake of the imaging unit,
Obtaining an angular velocity in at least one of three directions of the imaging unit;
Measuring a first time during which the angular velocity is equal to or less than a first threshold, and
When the first time is equal to or greater than a second threshold, instructing execution of focusing control of the imaging unit;
And a focusing control method. If the first time is equal to or greater than the second threshold, the second imaging unit takes a second time to determine whether there is a change in the scene based on the subject imaged by the imaging unit, and determines whether there is a change in the scene. Determining, further comprising:
The step of instructing execution of the focus control, when it is determined that the scene has changed, instructs execution of the focus control of the imaging unit,
A focusing control method according to claim 9. The step of determining whether or not the scene has changed includes:
When the first time is equal to or greater than the second threshold, sequentially acquiring evaluation values related to contrast of an image captured by the imaging unit;
When the difference between the previously obtained evaluation value and the currently obtained evaluation value is equal to or greater than a third threshold, determining that the scene has changed.
A focusing control method according to claim 10. Extending the second time when the obtained angular velocity is larger than a fourth threshold larger than the first threshold, further comprising:
A focusing control method according to claim 10. Capturing a moving image,
The step of instructing the execution of the focus control instructs to perform the focus control while continuously changing the focus position,
The focusing control method according to claim 9. The step of obtaining the angular velocity includes:
Obtaining information of an imaging operation for imaging an image by the imaging unit;
When the information of the imaging operation is obtained, including the step of obtaining the angular velocity,
A focusing control method according to claim 9. A moving body including an imaging unit and a gimbal unit on which the imaging unit is mounted and corrects shake of the imaging unit;
Obtaining an angular velocity in at least one of three directions of the imaging unit;
Measuring a first time during which the angular velocity is equal to or less than a first threshold, and
When the first time is equal to or greater than a second threshold, instructing the imaging unit to execute focusing control;
The program to execute. A moving body including an imaging unit and a gimbal unit on which the imaging unit is mounted and corrects shake of the imaging unit;
Obtaining an angular velocity in at least one of three directions of the imaging unit;
Measuring a first time during which the angular velocity is equal to or less than a first threshold, and
When the first time is equal to or greater than a second threshold, instructing the imaging unit to execute focusing control;
A computer-readable recording medium on which a program for executing the program is recorded.

Images