JP2018055096A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus having a damping function capable of effectively reducing an image blur due to vibrations.SOLUTION: An active vibration suppression dome camera 100 includes: actuators (tilt axis motor 3, pan axis motor 9) for defining an imaging direction of a camera module 2; a gyro sensor 1 for detecting vibrations; and a microcomputer 14 (control unit) that forms signals of a waveform of an opposite phase with respect to vibrations based on detection result by the gyro sensor 1 to thereby carry out damping action of the actuators.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an imaging apparatus, and more particularly to an imaging apparatus having a vibration damping function.

  In the dome camera used in the monitoring system, for example, the dome camera vibrates due to the influence of the vibration when passing through a car / train and the wind, and image blurring occurs in the output. Especially when zooming up, image blurring becomes annoying. In general, image blurring at a high frequency (for example, 30 Hz or more) is not obstructive, but it is felt that it is particularly disturbing at a low frequency (for example, 10 Hz or less). Also, when zooming up to discriminate falling objects on the road, visual discrimination may be difficult due to image blurring.

  “Image stabilizer (image stabilizer processing)” using image processing is widely known as a countermeasure against image blurring in a monitoring system. Some surveillance cameras have an image stabilizer provided in the camera body. In addition, when an image stabilizer is not provided in the camera body, a technique is also known in which an image with reduced image blur is displayed on a monitor by being installed between the monitoring camera and the monitor.

  As another image blur countermeasure, there is a correction unit using a lens unit. In addition, a technique is known in which a camera is moved by an actuator using a piezoelectric element provided corresponding to each of a pan direction and a tilt direction to reduce blur due to vibration (see, for example, Patent Document 1).

JP 2012-217078 A

  By the way, in the image stabilizer, for example, when an image blur is detected, a space for moving the image corresponding to the blur amount is required in advance. Therefore, about 70% of the center of the angle of view is extracted in advance and output to the monitor, and the remaining ± Since 15% is secured as a moving space, the disadvantage of a narrow angle of view occurs. In addition, when an object having a motion in an image is imaged, there is a drawback that the entire screen is distorted by the motion. In addition, the reduction effect varies depending on the frequency of vibration, and there is a problem that the reduction effect of image blur is often small particularly at low frequencies.

  Furthermore, when an object with motion is captured in the image, the image stabilizer causes distortion of the entire image due to the movement of the object. Not suitable for incoming monitoring.

  In a surveillance camera using a large lens unit, even if it vibrates, the lens in the lens unit is moved to reduce image blur so that the optical axis always stays at the same place. However, since the lens unit having the correction means is expensive and requires frequent maintenance of the mechanism portion, it is small and unsuitable for a dome camera used for surveillance purposes.

  The present invention has been made in view of such conventional circumstances, and an object thereof is to solve the above-described problems.

An apparatus according to the present invention is an imaging apparatus including a camera module and an actuator that determines an imaging direction of the camera module, and includes a sensor unit that detects vibration of the camera module, and a detection result of the sensor unit. And a control unit that forms a signal having a waveform having an antiphase with respect to the vibration and transmits the signal to the actuator to perform a vibration control operation of the actuator.
The control unit has a data table corresponding to the sensor unit and a data table of shooting distance, a detection value detected by the sensor unit, a data table corresponding to the sensor unit, a shooting distance obtained from the camera module, The vibration control operation may be controlled according to a comparison result by comparing with a data table of the shooting distance.
The control unit may further include a position information acquisition unit that acquires position information of the camera module at the time of starting the vibration suppression operation, and a correction unit that adjusts a positional shift due to drift of the sensor unit. Good.
Further, the control unit includes an alert table that holds a reference value for generating an alert of occurrence of an accident or abnormality with respect to a detection value of the sensor unit, and compares the reference value with a detection result of the sensor unit, The alert may be generated when a reference value is exceeded.
In addition, the sensor unit may include a gyro sensor that detects a change in movement in the rotation direction as an angular velocity as vibration of the camera module.
The sensor unit may include an acceleration sensor that detects a change in a linear motion as an acceleration as a vibration of the camera module.
The sensor unit may include a geomagnetic sensor that detects a change in azimuth movement as geomagnetism as vibration of the camera module.
In addition, an image processing unit may be provided that performs an image stabilizer process for reducing blur on the video captured by the camera module.

  As described above, according to the present invention, image blur due to vibration can be effectively reduced in an imaging apparatus having a vibration damping function.

It is a figure which shows the structure of the active vibration suppression dome camera based on 1st Embodiment. It is a functional block diagram of the active vibration suppression dome camera based on 1st Embodiment. It is a flowchart which shows the image blur reduction process based on 1st Embodiment. It is a figure explaining the difference in adjustment of the operation amount required according to the length of imaging distance based on 1st Embodiment. It is a functional block diagram of the active vibration suppression dome camera based on 2nd Embodiment. It is a flowchart which shows the image blur reduction process based on 2nd Embodiment. It is a functional block diagram of the active vibration suppression dome camera based on 3rd Embodiment. It is a flowchart which shows the image blur reduction process based on 3rd Embodiment.

  Next, modes for carrying out the present invention (hereinafter, simply referred to as “embodiments”) will be specifically described with reference to the drawings. In the following first embodiment, an example in which a gyro sensor is used as a sensor for detecting the vibration of the camera module is used. In the second embodiment, an example in which a 6-axis motion sensor on which a gyro sensor and an acceleration sensor are mounted is used. In the third embodiment, an example using a 9-axis motion sensor on which an acceleration sensor and a geomagnetic sensor are mounted will be described.

<First Embodiment>
FIG. 1 is a diagram illustrating the structure of an active vibration suppression dome camera 100. Here, a state in which a dome cover (not shown) that covers the inside and prevents rain and wind is removed is shown. FIG. 2 is a functional block diagram of the active vibration suppression dome camera 100, mainly focusing on the image blur reduction function due to vibration. Since image blur is often felt as an obstruction when zoomed up and at a low frequency (for example, 15 Hz or less), in this embodiment, vibration at a low frequency of 15 Hz or less is reduced.

  The active vibration suppression dome camera 100 is an outdoor specification and includes a camera module 2 covered with a dome cover. The camera module 2 can be driven to rotate in the two axis directions of the pan axis rotation direction 12 and the tilt axis rotation direction 6 by an actuator having the tilt axis motor 3 and the pan axis motor 9.

  As a turning mechanism for the pan axis rotation direction 12 and the tilt axis rotation direction 6, an upper mechanism unit 120 attached to the support arm 13 and a lower mechanism 140 attached to the lower side of the upper mechanism 120 are provided. The upper mechanism 120 drives the lower mechanism 140 to pivot in the pan axis rotation direction 12. That is, the lower mechanism 140 has a function as a pan axis movable part. Further, the lower mechanism 140 is provided with a mechanism for driving the camera module 2 to turn in the tilt axis direction.

  The lower mechanism 140 includes a camera module 2, a tilt axis motor 3 for rotating the tilt axis of the camera module 2, and a tilt axis servo motor driver 8. A gyro sensor 1 corresponding to three axes is attached to the camera module 2. The gyro sensor 1 acquires a gyro signal in three axis directions and transmits the signal to the microcomputer 14. That is, the vibration of the camera module 2 is detected using the gyro sensor 1. The gyro signal is output as an angular velocity.

  A belt 4 is stretched over a motor pulley 7 attached to the output shaft of the tilt axis motor 3 and a camera pulley 5 attached to the camera module 2, and the drive of the tilt axis motor 3 is performed by the motor pulley 7, the belt 4, and the camera. It is transmitted to the camera module 2 via the pulley 5.

  The tilt axis motor 3 is, for example, an AC servo motor, and includes a tilt axis rotary encoder 21 (see FIG. 2) that is a position detector. The lower mechanism 140 (pan axis movable part) having the camera module 2, the tilt axis motor 3 and the like includes a shaft (not shown). The shaft and the pan axis motor 9 are connected by a coupling 10.

  Cables from the gyro sensor 1, the camera module 2, and the tilt axis motor 3 constituting the lower mechanism 140 (pan axis movable part) are rotated 360 ° endlessly in the pan axis rotation direction 12 through a slip ring (not shown).

  In the upper mechanism 120, the pan axis motor 9, the microcomputer 14, and the pan axis servo motor driver 15 are attached to the pan base 11 fixed to the support arm 13.

  The pan axis motor 9 is an AC servo motor, similar to the tilt axis motor 3. Similar to the tilt axis motor 3, the position detector includes a pan axis rotary encoder 22 (see FIG. 2). The coupling 10 connected to the shaft of the above-described pan axis movable part 140 has, for example, a backlash-less structure.

  When the active vibration suppression dome camera 100 is installed in a place (not shown) where vibration is present, the camera module 2 is vibrated by propagating through the support arm 13 and each part of the active vibration suppression dome camera 100. This vibration causes image blur. The gyro sensor 1 detects the vibration, and the detection result is used for image blur reduction.

  The microcomputer 14 has an image blur reduction function. Here, as described above, image blurring due to low-frequency (for example, 15 Hz or less) vibration is reduced. For the reduction processing, the microcomputer 14, as shown in FIG. 2, includes a gyro signal processing unit 141, a camera module shooting distance control unit 150, an angular velocity data table 142, a shooting distance data table 151, and an operation An amount control unit 143, a default position information holding unit 144, a correction unit 145, an inverse pulse waveform output unit 146, an alert table 147, an alarm processing unit 148, and an image processing unit 149 are provided.

  The gyro signal processing unit 141 decomposes the gyro signal transmitted from the gyro sensor 1 into two gyro signals of the pan axis rotation direction 12 and the tilt axis rotation direction 6.

  The angular velocity data table 142 holds the correspondence relationship between the value of the gyro signal and the control ON / OFF algorithm and parameters.

  The camera module shooting distance control unit 150 holds the value when the lens focus distance is adjusted to the shooting distance or the specified distance of the lens 2a adjusted by the autofocus of the active vibration control dome camera 100.

  The shooting distance data table 151 holds a correspondence relationship between the value of the camera module shooting distance control unit 150 and the parameter of the operation amount control unit 143.

  The operation amount control unit 143 compares the two-way gyro signal decomposed by the gyro signal processing unit 141 with the angular velocity data table 142 and the value held by the camera module shooting distance control unit 150 and the shooting distance data table 151. Determine the control content. Specifically, the operation amount control unit 143 switches control ON / OFF and operation parameters of actuators (tilt axis motor 3 and pan axis motor 9). As a result, the optimum operation amount (operation amount in the tilt axis rotation direction 6 and operation amount in the pan axis rotation direction 12) to be added to the actuators (tilt axis motor 3, pan axis motor 9) is determined.

  The default position information holding unit 144 holds default position information of the camera module 2. In general, the gyro sensor 1 has a drift whose value changes due to a temperature change or a change with time. Therefore, the position of the camera module 2 at the start of active vibration suppression is detected by the rotary encoder (tilt axis rotary encoder 21, pan axis rotary encoder 22), and the detection result is recorded in the default position information holding unit 144 as default position information. The

  The correction unit 145 determines the position information of the camera module 2 (the direction of the pan axis rotation direction 12 and the tilt axis rotation direction 6) based on the detection results of the tilt axis rotary encoder 21 and the pan axis rotary encoder 22 during active vibration suppression. Is detected and compared with the default position information held in the default position information holding unit 144, and if a drift occurs, a correction amount for removing the influence of the drift is calculated. The operation amount control unit 143 reflects the correction and calculates the optimum operation amount for the actuator (tilt axis motor 3 and pan axis motor 9).

  The inverse pulse waveform output unit 146 forms an inverse phase pulse waveform for the pan axis and the tilt axis based on the calculated operation amount, and transmits the waveform to the pan axis servo motor driver 15 and the tilt axis servo motor driver 8.

  The pan axis servo motor driver 15 controls the pan axis motor 9 based on the reverse phase pulse waveform transmitted from the reverse pulse waveform output unit 146. As a result, the camera module 2 moves in an opposite phase with respect to the vibration in the pan axis rotation direction 12, thereby reducing image blur. Similarly, the tilt axis servo motor driver 8 controls the tilt axis motor 3 based on the reverse phase pulse waveform transmitted from the reverse pulse waveform output unit 146. As a result, the camera module 2 moves in an opposite phase with respect to the vibration in the tilt axis rotation direction 6, thereby reducing image blur.

  The alert table 147 holds a reference value for processing for detecting an apparatus abnormality / earthquake / accident based on the vibration of the gyro sensor 1. The alarm processing unit 148 compares the output value of the gyro sensor 1 with the reference value of the alert table 147, and generates a predetermined alert when the reference value is exceeded.

  The image processing unit 149 further performs image processing such as an image stabilizer on the video output from the active vibration suppression dome camera 100 in which the movement in the opposite phase to the vibration is reflected. Naturally, this image processing is not applied, and the blur reduction processing may be performed only by actuator control using the above-described antiphase pulse waveform. By applying hybrid processing that combines actuator control and image stabilizer processing, further image blur reduction can be realized. At this time, since a certain amount of image blur reduction has been performed before the image stabilizer processing, the “space for moving the image for the amount of blur” set during the image stabilizer processing can be reduced, and the angle of view can be reduced. Narrowing can be suppressed.

  FIG. 3 is a flowchart showing image blur reduction processing. The vibration suppression control (image blur reduction process) will be described more specifically with reference to the flowchart.

The gyro signal processing unit 141 of the microcomputer 14 acquires the gyro signal (angular velocity v _θ ) from the gyro sensor 1 (S10), and converts the acquired gyro signal (angular velocity v _θ ) into two directions of the pan axis and the tilt axis. Decompose (S12). The gyro signal processing unit 141 performs averaging by noise filter processing as necessary (S14).

Subsequently, the operation amount control unit 143 performs the case classification based on the angular velocity threshold with respect to the gyro signal, that is, the angular velocity (dθ _n / dt) (S16). When the angular velocity is small (a in S16), the operation amount control unit 143 determines that the vibration is small and there is no additional operation in the shake reduction process (S18), and sets the vibration suppression control to off (S20). In the angular velocity threshold determination, may be used a value after the decomposition in two directions of the gyro signals pan axis rotation direction 12 and the tilt axis direction of rotation 6, it may be used an angular velocity v _theta Predisassembly.

  If the angular velocity is moderate or large (b, c in S16) according to the angular velocity threshold value, correction value determination processing is performed using the angular velocity data table 142 (S24). However, when the angular velocity is high (c in S16), the operation amount control unit 143 performs acceleration / deceleration complementing processing as advance signal processing (S22).

  Acceleration / deceleration complement processing is performed when the operating amount of the actuator (motor rotation speed) is increased or decreased rapidly when the operating amount of the actuator is continuously changed. Since there is a delay, this is a process of gradually displacing the motor rotation speed to the specified operation amount in accordance with the rotation speed-torque characteristics of the motor (tilt shaft motor 3, pan axis motor 9).

In the correction value determination process (S24), the operation amount control unit 143 first performs a first operation amount calculation process using the angular velocity data table 142 (S26), and each of the pan axis rotation direction 12 and the tilt axis rotation direction 6 is performed. The operation amount (first operation amount) represented by Expression (1) is calculated.
Operation amount dθ _p / dt = f ₁ (θ _n , θ _n−1 )... Equation (1)

  Subsequently, the correction unit 145 obtains the position information (ENC) of the camera module 2 in the pan axis rotation direction 12 and the tilt axis rotation direction 6 based on the detection results of the tilt axis rotary encoder 21 and the pan axis rotary encoder 22, respectively. Is acquired (S28).

The correction unit 145 compares the default position information held in the default position information holding unit 144 with the position information (ENC), and calculates a correction amount for removing the influence of the drift when the drift occurs. . The operation amount control unit 143 reflects the correction, and calculates the optimum operation amount (second operation amount) of Expression (2) for the actuators (tilt axis motor 3 and pan axis motor 9) (S30).
Optimal manipulated variable dθ _p2 / dt = f ₂ (dθ _p / dt, ENC) (2)

The optimum operation amount dθ _p2 / dt may need to be adjusted depending on the distance taken by the active vibration suppression dome camera 100. In general, when only the gyro sensor 1 is used, it is not necessary to adjust the shooting distance, but it may be necessary in relation to other configurations or system configurations. Make the following adjustments as necessary.

  FIG. 4 is a diagram for explaining the difference in adjustment of the operation amount (pan axis operation amount) required according to the length of the shooting distance. 4A shows a case where the shooting distance is short, and FIG. 4B shows a case where the shooting distance is long. With respect to the normal position Pn of the camera module 2, the pan axis operation amount is different at the positions Pv1 and Pv2 of the camera module 2 during vibration. That is, when the shooting distance shown in FIG. 4A is short, the coefficient needs to be set large, and when the shooting distance shown in FIG. 4B is long, the coefficient needs to be set small.

Therefore, when the above adjustment is necessary, the adjustment amount D is determined by comparing the shooting distance held by the camera module shooting distance control unit 150 with the shooting distance data table 151, and the optimum amount shown in Expression (3) is determined. An operation amount dθ _p3 / dt is calculated (S32).
Optimal manipulated variable dθ _p3 / dt = f ₃ (dθ _p2 / dt, D) (3)

The calculated optimum operation amount is stored and applied to the operation amount calculated sequentially (S34). That is, it is used as θ _{n−1 at} the next timing for executing the calculation of the above-described formula (1).

When the optimum operation amount is calculated, the inverse pulse waveform output unit 146 performs leveling and then converts the optimum operation amount dθ _p2 / dt to pulse speed to generate an inverse phase pulse waveform (S36), and the pan axis The data is transmitted to the servo motor driver 15 and the tilt axis servo motor driver 8 (S38). As a result, the pan axis motor 9 and the tilt axis motor 3 cause the camera module 2 to move in a phase opposite to that of the vibration, thereby reducing image blur.

  As described above, according to the present embodiment, even when the active vibration suppression dome camera 100 is installed at a vibration generation place, vibration transmitted to the camera module 2 can be reduced, and the unsightlyness of the monitor output image can be reduced. It is possible to provide a clear video to the user. Further, in the image analysis, an image with reduced image blur can be used, and the image analysis accuracy can be improved. This makes it possible to ensure a clear image even when the accumulated image is captured during night monitoring.

<Second Embodiment>
FIG. 5 is a functional block diagram of the active vibration suppression dome camera 200. The present embodiment is a modification of the first embodiment, and the following description will mainly describe portions different from the first embodiment, and the same and similar structures and functions will be appropriately the same. The code | symbol is attached | subjected.

  Specifically, a 6-axis motion sensor 201 is provided instead of the gyro sensor 1 as a sensor for detecting the vibration of the camera module 2. Further, the microcomputer 14 is provided with an acceleration signal processing unit 241 and an acceleration data table 242.

  The 6-axis motion sensor 201 is attached to the camera module 2 similarly to the gyro sensor 1 described above. The 6-axis motion sensor 201 includes a 3-axis gyro sensor and a 3-axis acceleration sensor. That is, in the 6-axis motion sensor 201, the gyro sensor acquires a gyro signal in the triaxial direction and outputs it as an angular velocity, and the acceleration sensor outputs the acceleration in the triaxial direction, and transmits the output value to the microcomputer 14.

  The microcomputer 14 has the same function as that of the first embodiment, but acquires a signal of the six-axis motion sensor 201 instead of the signal of the gyro sensor 1 as an input signal. Since an acceleration signal is added as an output of the six-axis motion sensor 201, an acceleration signal processing unit 241 and an acceleration data table 242 are provided.

  The acceleration data table 144 holds a correspondence relationship between the acceleration signal value and the control ON / OFF algorithm or parameter.

  The operation amount control unit 145 includes a bi-directional gyro signal and angular velocity data table 143 decomposed by the gyro signal processing unit 141, an acceleration signal processing unit 241, an acceleration data table 242, and a camera module shooting distance control unit 152. The value to be held is compared with the shooting distance data table 153 to determine the control content.

  Similar to the gyro sensor 1, the six-axis motion sensor 1 has a drift whose value changes due to a temperature change or a change with time. Therefore, the position of the camera module 2 at the start of active vibration suppression is detected by the rotary encoder (tilt axis rotary encoder 21 and pan axis rotary encoder 22), and the detection result is recorded in the default position information holding unit 146 as default position information. The

  The alert table 147 holds reference values for processing for detecting an apparatus abnormality / earthquake / accident based on the signals of the gyro sensor 1 and acceleration sensor based on the gyro signal and acceleration signal of the 6-axis motion sensor 1. Has been. The alarm processing unit 148 compares the output value of the 6-axis motion sensor 201 gyro sensor or the output value of the acceleration sensor with the reference value of the alert table 147, and generates a predetermined alert when the reference value is exceeded.

  FIG. 6 is a flowchart showing image blur reduction processing. The vibration suppression control (image blur reduction process) will be described more specifically with reference to the flowchart.

  The default position information holding unit 144 obtains the position information (ENC (θ)) of the camera module 2 based on the detection results of the tilt axis rotary encoder 21 and the pan axis rotary encoder 22 and the pan axis rotation direction 12 and the tilt axis rotation direction. 6 is acquired (S210).

Next, gyro signal processing is executed (S212). In the gyro signal processing, the gyro signal processing unit 141 of the microcomputer 14 acquires the gyro signal (angular velocity v _θ ) from the six-axis motion sensor 201 (S214), and the acquired gyro signal (angular velocity v _θ ) is panned and tilted. The gyro signal is divided into two axial gyro signals (S216). The gyro signal processing unit 141 performs averaging by noise filter processing as necessary (S218).

In the correction value determination process by the gyro signal process, the operation amount control unit 143 first performs a first operation amount calculation process using the angular velocity data table 142, and formulas for each of the pan axis rotation direction 12 and the tilt axis rotation direction 6 ( A first operation amount J1 (operation amount dθ _rp / dt) indicated by 1A) is calculated (S220). The manipulated variable is calculated from the current gyro value (v _θn ) and the previous gyro value (v _θn−1 ).
Operation amount dθ _rp / dt = f ₁ (v _θn , v _θn−1 ) (1A)

The correction unit 145 compares the default position information held in the default position information holding unit 144 with the position information (ENC), and calculates a correction amount for removing the influence of the drift when the drift occurs. (S222). The operation amount control unit 143 reflects the correction and calculates the optimum operation amount dθ _rp2 / dt of the equation (2A) for the actuators (tilt axis motor 3 and pan axis motor 9), that is, the corrected first operation amount J1 ′. (S224).
Optimal manipulated _variable dθ _rp2 / dt = f ₂ (dθ _rp / dt, ENC) (2A)

  Next, acceleration signal processing is executed (S226). In this process, the acceleration signal processing unit 242 of the microcomputer 14 acquires an acceleration signal (acceleration A) from the six-axis motion sensor 201 (S228). The acceleration signal processing unit 241 performs averaging by noise filter processing as necessary (S230).

In the correction value determination process by the acceleration signal process, the operation amount control unit 143 first performs a second operation amount calculation process using the acceleration data table 242, and formulas for each of the pan axis rotation direction 12 and the tilt axis rotation direction 6 ( The second operation amount J2 (operation amount dθ _ap / dt) indicated by 3A) is calculated (S232). The operation amount is calculated from the current acceleration and the previous acceleration.
Operation amount dθ _ap / dt = f ₃ (A _n , A _n-1 )... Formula (3A)

The operation amount dθ _ap / dt needs to be adjusted according to the distance taken by the active vibration suppression dome camera 200. An adjustment amount D is determined by comparing the shooting distance held by the camera module shooting distance control unit 150 with the shooting distance data table 151 (S234), and the following equation (4A) is used as the corrected second operation amount J2 ′. ) To calculate the optimum operation amount dθ _ap2 / dt (S236).
Optimal manipulated _variable dθ _ap2 / dt = f ₄ (dθ _ap / dt, D) Expression (4A)
In general, the translational shake has little influence on the screen shake when the shooting distance exceeds a certain value. Therefore, the coefficient used in the above formula is set particularly low at a certain distance or more.

Subsequently, as shown in the following equation (5A), the operation amount control unit 143 has a corrected first operation amount (J1 ′) calculated from the gyro signal and a corrected second operation amount (J2 ′) calculated from the acceleration signal. To calculate a third manipulated variable J3 (= J1 ′ + J2 ′) (S238).
Operation amount dθ _p3 / dt = K _{1 ·} dθ _rp2 / dt + K _{2 ·} dθ _ap2 / dt
... Formula (5A)

Next, as the fourth operation amount calculation process, the operation amount control unit 143 compares the encoder value at the current position with the integral value of the pulse output and calculates the difference as shown in the following equation (6A). (S240). The calculated result is the fourth operation amount J4. The fourth operation amount J4 is used as a posture correction amount.
Operation amount θ _p4 = θ _ENC −θi (θi: integrated value of pulse output) Expression (6A)

After that, the operation amount control unit 143 combines the third operation amount J3 and the fourth operation amount J4 to calculate the fifth operation amount J5 as shown by the following equation (7A) (S242).
Operation amount dθ _p5 / dt = f ₅ (dθ _p3 / dt, θ _p4 ) (7A)

  When the fifth operation amount J5 is obtained, the operation amount control unit 143 compares the calculated fifth operation amount J5 with a predetermined threshold value (S244). When the fifth operation amount J5 exceeds a certain threshold value (Y in S244), the operation amount control unit 143 converts the fifth operation amount J5 into a pulse, and the pan axis servo motor driver 15 and the tilt axis servo motor driver. (S246). As a result, the pan axis motor 9 and the tilt axis motor 3 cause the camera module 2 to move in a phase opposite to that of the vibration, thereby reducing image blur. The manipulated variable control unit 143 integrates the output pulse number and uses it for the next posture control calculation (S248).

  On the other hand, when the calculated fifth operation amount J5 is equal to or less than a certain threshold value (N in S244), the operation amount control unit 143 determines that there is no vibration suppression control operation (S250) and turns off the control (S252).

  As described above, according to the present embodiment, similarly to the first embodiment, even when the active vibration suppression dome camera 200 is installed at a vibration generation place, vibration transmitted to the camera module 2 can be reduced. It is possible to reduce unpleasantness of the monitor output video and provide a clear video to the user. Further, in the image analysis, an image with reduced image blur can be used, and the image analysis accuracy can be improved. This makes it possible to ensure a clear image even when the accumulated image is captured during night monitoring.

<Third Embodiment>
FIG. 7 is a functional block diagram of the active vibration suppression dome camera 300 of the present embodiment. The present embodiment is a modification of the first embodiment and the second embodiment, and the following description will mainly describe portions different from the first embodiment and the second embodiment. The same and similar structures / functions are given the same reference numerals as appropriate.

  Specifically, a nine-axis motion sensor 301 is provided as a sensor for detecting vibration of the camera module 2 instead of the gyro sensor 1 of the first embodiment (FIG. 2). Further, the microcomputer 14 includes an acceleration signal processing unit 241, an acceleration data table 242, a gravity direction data table 342, a geomagnetic signal processing unit 341, and a shooting direction data table 343.

  The 9-axis motion sensor 301 is attached to the camera module 2 similarly to the gyro sensor 1 described above. The 9-axis motion sensor 301 includes a 3-axis gyro sensor, a 3-axis acceleration sensor, and a 3-axis geomagnetic sensor. That is, in the nine-axis motion sensor 301, the gyro sensor acquires a triaxial gyro signal and outputs it as an angular velocity, the acceleration sensor outputs triaxial acceleration, the geomagnetic sensor outputs triaxial geomagnetism, Those output values are transmitted to the microcomputer 14.

  The microcomputer 14 has the same function as that of the first embodiment, but acquires a signal of the 9-axis motion sensor 301 as an input signal instead of the signal of the gyro sensor 1. Since an acceleration signal and a geomagnetic signal are added as the output of the nine-axis motion sensor 301, an acceleration signal processing unit 241, an acceleration data table 242, a gravity direction data table 342, and a shooting direction data table 343 are provided. Yes.

  The acceleration data table 242 holds a correspondence relationship between the acceleration signal value and the control ON / OFF algorithm or parameter.

  The gravity direction data table 342 holds the inclination angle of the sensor (9-axis motion sensor 301) with respect to the vertical direction. Specifically, it is calculated from the magnitude of the vertical value of the acceleration sensor. This makes it possible to always maintain the tilt angle with respect to the vertical direction even if the posture of the camera changes due to vibration.

  The shooting direction data table 343 holds the azimuth angle of the (9-axis motion sensor 301) with respect to the north. Calculated from the output of the geomagnetic sensor. This makes it possible to always maintain the tilt angle with respect to the north direction even if the posture of the camera changes due to vibration.

  The operation amount control unit 143 includes a bi-directional gyro signal and angular velocity data table 142 decomposed by the gyro signal processing unit 141, an acceleration signal processing unit 241, an acceleration data table 242, a gravity direction data table 342, and a shooting direction. And the control contents are determined.

  Similar to the gyro sensor 1, the 9-axis motion sensor 301 has a drift whose value changes due to a temperature change or a change with time. Therefore, the position of the camera module 2 at the start of active vibration suppression is detected by the rotary encoder (tilt axis rotary encoder 21 and pan axis rotary encoder 22), and the detection result is recorded in the default position information holding unit 146 as default position information. The

  The alert table 147 includes reference values for processing for detecting an abnormality / earthquake / accident based on the signals of the gyro sensor, acceleration sensor and geomagnetic sensor based on the gyro signal and acceleration signal of the 9-axis motion sensor 301. Is held. The alarm processing unit 148 compares the output value of the gyro sensor of the 9-axis motion sensor 301, the output value of the acceleration sensor, the output value of the geomagnetic sensor, and the reference value of the alert table 147, and if the reference value is exceeded, Generate a predetermined alert.

  FIG. 8 is a flowchart showing image blur reduction processing. The vibration suppression control (image blur reduction process) will be described more specifically with reference to the flowchart.

  The default position information holding unit 144 obtains the position information (ENC (θ)) of the camera module 2 based on the detection results of the tilt axis rotary encoder 21 and the pan axis rotary encoder 22 and the pan axis rotation direction 12 and the tilt axis rotation direction. 6 is acquired (S310).

  Next, processing of signals output from the 9-axis motion sensor 301 is executed (S312). First, when the microcomputer 14 acquires a sensor value from the 9-axis motion sensor (S314), the microcomputer 14 smoothes the data for 9 axes with a noise filter (S316).

In the gyro signal processing, the gyro signal processing unit 141 of the microcomputer 14 acquires the gyro signal (angular velocity v _θ ) from the 9-axis motion sensor 301 (S318), and the acquired gyro signal (angular velocity v _θ ) is panned and tilted. The gyro signal is divided into two axial gyro signals (S320).

  In the acceleration signal processing, the acceleration signal processing unit 242 of the microcomputer 14 acquires the acceleration signal (acceleration A) from the 9-axis motion sensor 301 (S322), and performs direction decomposition of the acquired acceleration signal (acceleration A) (S324). Then, the acceleration signal in the vertical direction is calculated (S326).

  In the geomagnetism signal processing, the geomagnetism signal processing unit 341 of the microcomputer 14 acquires a geomagnetism signal (gemagnetism D) from the 9-axis motion sensor 301 (S328), and performs direction decomposition of the acquired geomagnetism signal (gemagnetism D) (S330). Then, the shooting direction of the active vibration suppression dome camera 300 is calculated (S332).

In the correction value determination process by the gyro signal process (S334), the operation amount control unit 143 first performs a first operation amount calculation process using the angular velocity data table 142, and each of the pan axis rotation direction 12 and the tilt axis rotation direction 6 is performed. The first operation amount J1 (operation amount dθ _rp / dt) represented by the equation (1B) is calculated (S336), and drift correction processing is performed (S338). The manipulated variable is calculated from the current gyro value (v _θn ) and the previous gyro value (v _θn−1 ).
Operation amount dθ _rp / dt = f ₁ (v _θn , v _θn−1 ) (1B)

The correction unit 145 uses the shooting direction data table as the pan axis correction value and the gravity direction data table as the tilt axis correction value to correct the drift, and the second operation amount (J2) is expressed by the equations (2B) and (2C). ) (S340).
Optimum manipulated _variable dθ _rp2 / dt = f ₂ (dθ _rp / dt, shooting direction, ENC) (2B)
Optimal manipulated _variable dθ _rp2 / dt = f ₂ (dθ _rp / dt, direction of gravity, ENC) (2C)

  When the second operation amount J2 is obtained, the operation amount control unit 143 compares the calculated second operation amount J2 with a predetermined threshold (S342). When the second manipulated variable J2 exceeds a certain threshold (Y in S342), the manipulated variable control unit 143 converts the second manipulated variable J2 into a pulse, and the pan axis servo motor driver 15 and the tilt axis servo motor driver. 8 is transmitted (S344). As a result, the pan axis motor 9 and the tilt axis motor 3 cause the camera module 2 to move in a phase opposite to that of the vibration, thereby reducing image blur. The manipulated variable control unit 143 integrates the output pulse number and uses it for the next posture control calculation (S346).

  On the other hand, when the calculated second operation amount J2 is equal to or smaller than a certain threshold value (N in S342), the operation amount control unit 143 determines that no vibration suppression control operation is performed (S348), and the control is turned off (S350).

  As described above, according to this embodiment, similarly to the first embodiment and the second embodiment, even when the active vibration suppression dome camera 300 is installed at the vibration generation place, the vibration transmitted to the camera module 2 is reduced. Therefore, it is possible to reduce unpleasantness of the monitor output video and provide a clear video to the user. Further, in the image analysis, an image with reduced image blur can be used, and the image analysis accuracy can be improved. This makes it possible to ensure a clear image even when the accumulated image is captured during night monitoring.

  The present invention has been described based on the embodiments. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to combinations of these components, and such modifications are also within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Gyro sensor 2 Camera module 2a Camera lens 3 Tilt axis motor 4 Belt 5 Camera pulley 6 Tilt axis rotation direction 7 Motor pulley 8 Tilt axis servo motor driver 9 Pan axis motor 10 Coupling 11 Pan base 12 Pan axis rotation direction 13 Support arm 14 Microcomputer 15 Pan axis servo motor driver 21 Tilt axis rotary encoder 22 Pan axis rotary encoder 100, 200, 300 Active vibration control dome camera (imaging device)
141 Gyro signal processing unit 142 Angular velocity data table 143 Operation amount control unit 144 Default position information holding unit 145 Correction unit 146 Reverse pulse waveform output unit 147 Alert table 148 Alarm processing unit 149 Image processing unit 150 Camera module shooting distance control unit 151 Shooting distance data table 201 6-axis motion sensor 241 Acceleration signal processing unit 242 Acceleration data table 301 9-axis motion sensor 341 Geomagnetic signal processing unit 342 Gravity direction data table 343 Shooting direction data table

Claims (8)

An imaging apparatus comprising a camera module and an actuator for determining an imaging direction of the camera module,
A sensor unit for detecting vibration of the camera module;
Based on the detection result of the sensor unit, a control unit that forms a signal having a waveform in an antiphase with respect to the vibration and transmits the signal to the actuator to perform a vibration control operation of the actuator;
An imaging apparatus comprising:   The control unit has a data table corresponding to the sensor unit and a data table of shooting distance, a detection value detected by the sensor unit, a data table corresponding to the sensor unit, a shooting distance obtained from the camera module, The imaging apparatus according to claim 1, wherein the image pickup apparatus compares the imaging distance data table and controls the vibration control operation according to the comparison result. The controller is
A position information acquisition unit for acquiring position information of the camera module at the time of starting the vibration suppression operation;
A correction unit for adjusting a positional shift due to drift of the sensor unit;
The imaging apparatus according to claim 1, further comprising:   The control unit includes an alert table that holds a reference value for generating an alert of an accident or abnormality with respect to a detection value of the sensor unit, and compares the reference value with a detection result of the sensor unit, and the reference value The imaging apparatus according to any one of claims 1 to 3, wherein the alert is generated when the number exceeds.   The imaging device according to any one of claims 1 to 4, wherein the sensor unit includes a gyro sensor that detects a change in a rotational direction as an angular velocity as vibration of the camera module.   The imaging apparatus according to claim 5, wherein the sensor unit includes an acceleration sensor that detects a change in a linear motion as an acceleration as vibration of the camera module.   The imaging device according to claim 5, wherein the sensor unit includes a geomagnetic sensor that detects a change in azimuth movement as geomagnetism as vibration of the camera module.   The imaging apparatus according to claim 1, further comprising: an image processing unit that performs an image stabilizer process for reducing blur on an image captured by the camera module.

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