Control device, control method, medium, and program product

Abstract

The invention discloses a control apparatus, a control method, a medium, and a program product. The control apparatus includes a driving unit configured to change a direction of an imaging unit, and a control unit configured to perform driving control of the driving unit in a case where the direction of the imaging unit is to be changed. In a case where a direction of the imaging unit is changed and a speed of the driving unit does not fall within a predetermined speed range, the control unit applies to the driving unit a first current value applied to the driving unit during normal driving, and applying a second current value larger than the first current value to the driving unit in a case where the speed of the driving unit falls within the predetermined speed range.

Description

Technical Field

[0001] The present invention generally relates to a control device, a control method, a medium and a program product, and more particularly to a technology for controlling a camera posture. Background Art

[0002] In a monitoring system or a video distribution system, a pan / tilt (PT) camera is used that can be controlled to view video via a network, a dedicated line, a remote controller, etc. The PT camera includes a mechanism that can rotate in a pan direction (horizontal direction) and a tilt direction (vertical direction), and can change the shooting direction.

[0003] According to the mechanical characteristics of the PT drive unit, when driven at a speed within a predetermined speed range, resonance may generate vibration or sound, and when the speed changes slightly periodically, uneven speed may occur. In video distribution, emphasis is placed on video quality, and quiet and smooth PT driving is required. Japanese Patent Laid-Open No. 9-18747 (Patent Document 1) discloses a method of switching a current value according to an operation mode to drive a motor from a low speed to a high speed while suppressing vibration.

[0004] However, in the technology described in Patent Document 1, since the current value increases in the high speed mode, the resonance sound becomes louder. Summary of the invention

[0005] According to one aspect of the present invention, a control device for controlling a camera unit capable of changing direction comprises: a drive unit configured to change the direction of the camera unit; and a control unit configured to perform drive control of the drive unit when the direction of the camera unit is to be changed, wherein, when the direction of the camera unit is changed and when the speed of the drive unit does not fall within a predetermined speed range, the control unit applies a first current value that is applied during normal driving to the drive unit, and when the direction of the camera unit is changed and when the speed of the drive unit falls within the predetermined speed range, the control unit applies a second current value that is larger than the first current value to the drive unit.

[0006] According to another aspect of the present invention, a control method for a control device of a camera unit capable of changing direction comprises: when the direction of the camera unit is changed and when the speed of the drive unit does not fall within a predetermined speed range, driving is performed by applying a first current value applied during normal driving to the drive unit, and when the direction of the camera unit is changed and when the speed of the drive unit falls within the predetermined speed range, driving is performed by applying a second current value larger than the first current value to the drive unit.

[0007] According to the present invention, more appropriate PT drive control can be performed.

[0008] Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings). BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention.

[0010] Figure 1 is a block diagram showing the functional blocks of a PTZ camera;

[0011] Figure 2A and Figure 2B This is a diagram used to explain the mechanical structure and movable range of a PTZ camera.

[0012] Figure 3A and Figure 3B are a timing chart and a graph showing acceleration / deceleration control during a shooting operation;

[0013] Figure 4 is a flow chart of PT control (first embodiment);

[0014] Figure 5 is a flow chart of PT control (second embodiment);

[0015] Figure 6 is a flow chart of PT control (third embodiment); and

[0016] Figure 7 It is a flowchart of PT control (fourth embodiment). DETAILED DESCRIPTION

[0017] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the scope of the claimed invention. A plurality of features are described in the embodiments, but the invention requiring all of these features is not limited, and a plurality of such features may be appropriately combined. In addition, in the accompanying drawings, the same reference numerals are assigned to the same or similar configurations, and redundant descriptions thereof are omitted.

[0018] (First embodiment)

[0019] As a first embodiment of the control device according to the present invention, change control of a current value applied to a drive unit of a pan / tilt / zoom (PTZ) camera will be described as an example.

[0020] <Device Layout>

[0021] Figure 11 is a block diagram showing functional blocks of the PTZ camera 100. The PTZ camera 100 is connected to a client device (information processing device) (not shown) via a network 150 so that they can communicate with each other. A user can send various camera control commands to the PTZ camera 100 via the client device.

[0022] The PTZ camera 100 includes an imaging unit 101 , a pan drive unit 102 , a tilt drive unit 103 , a zoom drive unit 104 , an image processing unit 105 , a PTZ control unit 106 , a system control unit 107 , and a communication unit 108 .

[0023] The imaging unit 101 is composed of a lens for imaging including a focus lens and a zoom lens, an image sensor, and a mechanical drive system and circuit for driving the above components. The image sensor forms a subject image through the lens for imaging, and the image sensor generates an electrical signal representing the subject image.

[0024] The panning drive unit 102 is formed of a mechanical drive system for performing a panning operation, a motor used as a drive source, a motor driver, etc., and is controlled by a PTZ control unit 106. The PTZ control unit 106 sets a drive amount, speed, acceleration, drive current, etc. in the panning drive unit 102, and starts driving by a drive start command. Figure 2A and Figure 2B Describe the detailed arrangement.

[0025] The tilt drive unit 103 is formed of a mechanical drive system for performing a tilt operation, a motor serving as a drive source, a motor driver, and the like, and is controlled by a PTZ control unit 106. The PTZ control unit 106 sets a drive amount, a speed, an acceleration, a drive current, and the like in the tilt drive unit 103, and starts driving by a drive start command. Figure 2A and Figure 2B Describe the detailed arrangement.

[0026] The zoom driving unit 104 is a driving unit that changes the imaging angle of view of the imaging unit 101. The zoom driving unit 104 is formed of a mechanical driving system for performing a zoom operation, a motor serving as a driving source, a motor driver, and the like, and is controlled by the PTZ control unit 106.

[0027] The image processing unit 105 performs predetermined development processing, compression encoding processing, etc. on the electrical signal generated by the imaging unit 101 to generate image data, and transmits the image data to the system control unit 107. If receiving an image quality adjustment instruction from the system control unit 107, the image processing unit 105 adjusts the image quality.

[0028] The PTZ control unit 106 processes instructions related to PTZ control received from the system control unit 107. For example, based on the pan / tilt instructions received from the system control unit 107, the PTZ control unit 106 performs control of the driving amount, speed, and acceleration / deceleration, initialization operation, etc. of each of the pan drive unit 102 and the tilt drive unit 103. In addition, based on the zoom instruction received from the system control unit 107, the PTZ control unit 106 performs control of the driving amount, speed, and acceleration / deceleration, initialization operation, etc. of the zoom drive unit 104. The PTZ control unit 106 may adopt a software implementation form implemented when the CPU executes a program or a hardware implementation form such as an application specific integrated circuit (ASIC). Alternatively, the PTZ control unit 106 may be implemented by combining software implementation and hardware implementation.

[0029] The system control unit 107 controls the entire PTZ camera 100. In addition, the system control unit 107 distributes the image data generated by the image processing unit 105 to the client device (not shown) via the communication unit 108. In addition, the system control unit 107 analyzes the camera control command transmitted from the client device (not shown) via the communication unit 108, and performs processing corresponding to the command. For example, the system control unit 107 sends an image quality adjustment instruction to the image processing unit 105, and sends a PTZ operation instruction and a shooting operation instruction to the PTZ control unit 106. The system control unit 107 may be implemented in a software implementation form implemented when the CPU executes a program or in a hardware implementation form such as an application specific integrated circuit (ASIC). Alternatively, the system control unit 107 may be implemented by combining software implementation and hardware implementation.

[0030] The communication unit 108 receives a camera control command transmitted from a client device, and transfers it to the system control unit 107. Furthermore, the communication unit 108 transmits image data generated by the image processing unit 105 and a response to the camera control command to a client device (not shown).

[0031] Note that the PTZ camera 100 in this embodiment is not limited to Figure 1 For example, the PTZ camera 100 may be equipped with a serial digital interface (SDI) or a high-definition multimedia interface (HDMI). The communication unit 108 may be connected to the network 150 by a video output terminal, an audio input / output unit, or an external device input / output unit. The communication unit 108 may be connected by a wired connection or a wireless connection. The communication unit 108 may not be connected to the network 150, but may be connected to another device by serial communication or the like.

[0032] Figure 2A and 2B 1 is a view for explaining the mechanical structure and movable range of the PTZ camera 100 . Figure 2A is a view of the attached PTZ camera 100 when viewed from the top (pitch angle of "+90°") direction. Figure 2B is a view of a vertically mounted PTZ camera 100 when viewed from the side. Figure 2A and Figure 2B In the embodiment, the PTZ camera 100 is formed by a bottom casing 201 , a turntable 202 , a camera head support 203 , and a camera head 204 .

[0033] In the following description, the axis of the PTZ camera 100 in the vertical direction is defined as the vertical axis, and the axis orthogonal to the vertical axis is defined as the horizontal axis, while describing the operation of the PT movable unit. Figure 2A In the figure, with the vertical axis perpendicular to the paper surface as the center, the clockwise direction is the positive (+) direction of the panning angle, and the counterclockwise direction is the negative (-) direction of the panning angle. Figure 2B In the figure, with the axis perpendicular to the paper surface as the center, the clockwise direction is the positive direction of the pitch angle, and the counterclockwise direction is the negative direction of the pitch angle.

[0034] The pan drive unit 102 is formed by a bottom case 201 and a turntable 202, and the turntable 202 rotates in the horizontal direction with a vertical axis as the center. The pan drive unit 102 in this embodiment can rotate from "-170°" to "+170°" in the pan direction with a given reference direction (0°) as the center.

[0035] The tilt driving unit 103 is formed by a camera head 204 and a camera head support 203 provided on a turntable 202, and the camera head 204 rotates in a vertical direction with a horizontal axis as a center. Figure 2B As shown, the pitch driving unit 103 of this embodiment is installed vertically, and it can rotate from the oblique downward direction "-30°" to the oblique upward direction "+100°" based on the horizontal direction (0°).

[0036] Figure 2A and Figure 2B Each angle shown in represents an angle that a user can indicate to the PTZ camera 100. The PTZ control unit 106 Figure 2A and Figure 2B The PTZ camera 100 of this embodiment can change the shooting direction by rotating the camera head 204 in the pan direction and the tilt direction, thereby being able to shoot a wide range. Note that the PTZ camera 100 is not limited to Figure 2A and Figure 2B For example, the PTZ camera 100 can be driven 360° (endlessly) in the pan direction and / or the tilt direction.

[0037] <Shooting Operation>

[0038] The shooting operation means a control operation of performing PT driving so that when the posture (shooting direction) of the camera is changed, the panning driving and the tilting driving are started and stopped at approximately the same time. Note that the same control can also be performed on the zoom driving.

[0039] Figure 3A and Figure 3B 1 and 2 are a timing chart and a graph showing acceleration / deceleration control during a photographing operation. Figure 3A 1 is a timing chart showing a change in speed of each of the pan drive unit 102 and the tilt drive unit 103 at the time of a shooting operation. Figure 3B is a graph showing the relationship between the pan movement amount and the pitch movement amount.

[0040] exist Figure 3A , the horizontal axis represents time, the vertical axis represents speed, the solid line represents the pan speed, and the dotted line represents the tilt speed. More specifically, the pan drive unit 102 and the tilt drive unit 103 start driving substantially at the same time at "0 seconds", perform 4 seconds of acceleration drive control, constant speed drive control, and 4 seconds of deceleration drive control, and then stop driving substantially at the same time at "14 seconds". During the constant speed drive, the pan drive unit 102 performs constant speed drive at "3 times / second", and the tilt drive unit 103 performs constant speed drive at "4 times / second". The movement amount of the pan drive unit 102 is "30°", and the movement amount of the tilt drive unit 103 is "40°".

[0041] exist Figure 3B In the figure, the horizontal axis represents the pan movement, and the vertical axis represents the pitch movement. Figure 3B Shown Figure 3A The relationship between the pan movement and the pitch movement when driven at the speed shown. Figure 3B In the linear drive, the ratio between the pan movement amount and the tilt movement amount is constant (the curve is a straight line), and the relationship between the pan movement amount and the tilt movement amount is linear (linear drive). In the linear drive, the shooting direction of the camera moves linearly. On the other hand, for example, if the acceleration / deceleration time between the pan drive unit 102 and the tilt drive unit 103 is different, the curve graph is not a straight line, and the linear drive is not performed.

[0042] In order to perform the shooting operation, the PTZ control unit 106 needs to pre-register the target positions of the pan drive unit 102, the tilt drive unit 103, and the zoom drive unit 104. For example, the target position is registered as "shooting 1". It is assumed that in "shooting 1", the pan position is "30°", the tilt position is "40°", and the zoom position is "telephoto end position". It is assumed here that the shooting operation is performed by specifying the moving speed or the moving time.

[0043] Consider a case where a movement to the "shooting 1" position is performed by specifying a movement time of "14 seconds" when the current position is the pan position "0°", the tilt position "0°", and the zoom position "telephoto end position". In this case, the PTZ control unit 106 calculates the pan movement amount as "30°", the tilt movement amount as "40°", and the zoom movement amount as "0 (no movement)".

[0044] In order to stop the driving 14 seconds after the start of the panning and tilting driving, the PTZ control unit 106 calculates the speed and acceleration of each driving unit and sets them. Figure 3A As shown, t represents the moving time, ta represents the acceleration time, td represents the deceleration time, and v represents the speed of constant speed drive. In this case, by obtaining the trapezoidal area, the movement amount x can be given by the following formula:

[0045]

[0046] Therefore, the velocity v can be calculated by transforming equation (1) to obtain equation (2).

[0047]

[0048] Assume that the acceleration time (ta) is "4 seconds" and the deceleration time (td) is "4 seconds". In this case, the constant speed driving speed of pan is calculated as "3 times / second" so as to drive with a pan movement amount of "30°" in 14 seconds. Similarly, the constant speed driving speed of tilt is calculated as "4 times / second" so as to drive with a tilt movement amount of "40°" in 14 seconds.

[0049] Furthermore, if the movement to the position of "Shot 1" is performed by specifying the movement speed instead of the movement time, v in equation (1) is known. Therefore, the movement time t can be calculated by the following equation:

[0050]

[0051] The moving time of each driving unit is calculated by equation (3), and the longest one of the calculated moving times is set as the moving time during the shooting operation. Then, the speed is calculated by equation (2) so that the other driving units can move within the set moving time.

[0052] Consider the case where movement to the "shooting 1" position is performed by specifying a moving speed of "4 times / second" when the current position is the pan position "0°", the tilt position "0°", and the zoom position "telephoto end position". In this case, if the moving time of each drive unit is obtained by equation (3), the moving time of the pitch drive unit is the longest "14 seconds". Therefore, the moving time during the shooting operation is set to "14 seconds". In addition, the speed of the pitch drive unit is the specified "4 times / second". By setting the moving time to "14 seconds", the speed of the pan drive unit is calculated using equation (2), thereby obtaining "3 times / second". Since the speed and acceleration time are known, the acceleration can be obtained by "speed ÷ acceleration time".

[0053] The PTZ control unit 106 can implement a photographing operation by setting the speed and acceleration thus obtained in the pan drive unit 102 and the tilt drive unit 103 .

[0054] <Device Operation>

[0055] As described in the "Background of the Invention", according to the mechanical characteristics of the PT drive unit, when driven at a speed within a predetermined speed range, resonance may generate vibration or sound, and when the speed changes slightly periodically, uneven speed may occur. As described above, the speed / acceleration of the shooting operation can be obtained by calculation, but according to the specified value (moving speed or moving time), the calculated speed falls within the above-mentioned predetermined speed range.

[0056] In order to cope with this situation, in the first embodiment, if the calculated speed falls within the above-mentioned predetermined speed range, PT driving is performed by increasing the current value applied to each drive unit. If the current value increases, the torque of the drive unit increases, thereby improving the holding force of the imaging unit 101 (the imaging unit 101 becomes more difficult to move). Therefore, even if PT driving is performed at a speed within the above-mentioned predetermined speed range, the occurrence of vibration and speed unevenness can be reduced.

[0057] Note that if the current value is increased, the torque of the drive unit will also increase, so the resonance sound may become louder. However, the speed range where speed unevenness occurs is usually different from the speed range where the resonance sound occurs, so even if the current value is increased within the speed range where speed unevenness occurs, the resonance sound is unlikely to be affected.

[0058] Figure 4 is a flow chart of the PT control according to the first embodiment. More specifically, Figure 4 4 shows PT control performed by the PTZ control unit 106. Upon receiving a photographing operation start command via the system control unit 107, the PTZ control unit 106 starts a sequence in a photographing operation (step S401).

[0059] In step S402, the PTZ control unit 106 accepts the designation of the target position of the pan and tilt positions in the shooting operation and the movement time. For example, the designation is accepted from a client device (not shown) operated by the user via the communication unit 108 and the system control unit 107. In addition, the current position of the pan and tilt positions is acquired. Then, the PTZ control unit 106 calculates the movement amount of each drive unit based on the current position and the target position, and calculates the speed / acceleration of each drive unit based on the designated movement time.

[0060] As described above, if a moving speed is specified instead of a moving time, the moving time of each drive unit is calculated based on the specified moving speed, and the longest time is set as the moving time. For example, a moving speed that obtains the longer one of the moving distances of pan and pitch is accepted from the user. At this time, it is preferably preset not to accept a moving speed within the resonance speed range. Then, the speed / acceleration of each drive unit is calculated using the set moving time.

[0061] In step S403, the PTZ control unit 106 determines whether the speed (the speed of the constant speed drive) calculated in step S402 falls within a predetermined speed range. For example, it is known in advance that uneven speeds occur in the speed range of "2.5° / sec to 3.5° / sec" in the pan drive unit 102, while there is no speed range in which uneven speeds occur in the tilt drive unit 103. In this case, the speed range of "2.5° / sec to 3.5° / sec" is used only in the pan drive unit 102 as the predetermined speed range. If the speed of the pan drive unit 102 calculated in step S402 falls outside the predetermined speed range, the process proceeds to step S404. Alternatively, if the speed of the pan drive unit 102 falls within the predetermined speed range, the process proceeds to step S405. In other words, if the speed (the speed of the constant speed drive) calculated in step S402 is higher than the upper limit value of the predetermined speed range, or lower than the lower limit value of the predetermined speed range, the process proceeds to step S404.

[0062] Note that, in this example, there is a speed range in which uneven speed occurs only in the pan drive unit 102. However, a predetermined speed range may be set for the tilt drive unit 103, and determination may be performed.

[0063] In step S404, the PTZ control unit 106 sets the current applied to the drive unit (the pan drive unit 102 or the tilt drive unit 103) to "12", that is, the value of the current value 1 (I1). In this example, the current value is 0 to 31, and the larger the value, the larger the current value. Note that the current value 1 is a reference current value set at startup (current value at normal drive).

[0064] In step S405, the PTZ control unit 106 sets the current applied to the drive unit (the pan drive unit 102 or the tilt drive unit 103) whose speed is determined to fall within the predetermined speed range in step S403 to "16", that is, the value of the current value 2 (I2). Note that the setting value of the current value 2 is greater than the current value 1 (that is, the current value is larger). This increases the motor drive torque of the drive unit (the pan drive unit 102 and / or the tilt drive unit 103), thereby reducing the speed unevenness.

[0065] In step S406, the PTZ control unit 106 starts driving the pan drive unit 102 and the tilt drive unit 103 (and the zoom drive unit 104) at the speed / acceleration calculated in step S402 using the current value set in step S404 and / or step S405. Figure 3A Each driving unit is driven at the speed shown. At this time, the pan driving unit 102 performs driving at a current value of "16", and the tilt driving unit 103 performs driving at a current value of "12".

[0066] In step S407 , the PTZ control unit 106 ends the sequence at the time of the photographing operation.

[0067] As described above, according to the first embodiment, at the time of shooting operation, the current value to be applied to the driving unit whose calculated speed (speed of constant speed driving) falls within the predetermined speed range is set to be greater than the reference current value (current value during normal driving). By increasing the current value to be applied, the motor driving torque is increased, so that the speed unevenness can be reduced. Alternatively, if the calculated speed falls outside the predetermined speed range, the current value to be applied is set to the reference current value (current value during normal driving), so that the driving sound or vibration does not become larger. In addition, since linear driving can be performed at the time of shooting operation, the quality of the obtained video is improved.

[0068] Note that in the above description, it is determined whether the calculated speed falls within the predetermined speed range, and the setting of the current value is changed. However, for example, the settings of the speed and the current value may be stored in advance in a table or the like, and the setting of the current value may be changed by reading the value from the table. In the above description, for the drive unit whose calculated speed falls within the predetermined speed range, the current value is made larger during the entire drive control period. However, the current value may be made larger only during the period in which the calculated speed falls within the predetermined speed range.

[0069] In addition, by increasing the current value, the power consumption of the entire PTZ camera 100 increases. Therefore, if the current value to be applied to the drive unit increases, power control that reduces the power consumption of another functional unit (another drive system, etc.) can be performed. For example, it can be configured to stop supplying power to an unused functional unit.

[0070] (Second embodiment)

[0071] The second embodiment will describe another form of change control of the current value to be applied to the drive unit. More specifically, an example of changing the current value based on whether the speed falls within (passes) a predetermined speed range during acceleration / deceleration will be described. Note that the arrangement of the PTZ camera ( Figure 1 , Figure 2A and Figure 2B ) is the same as in the first embodiment, so its description will be omitted.

[0072] <Device Operation>

[0073] Figure 5 is a flow chart of the PT control according to the second embodiment. More specifically, Figure 5 4 shows the PT control performed by the PTZ control unit 106. Note that the operations of steps S402 and S404 to S406 are the same as those of the first embodiment ( Figure 4 ) are the same, and description thereof will be omitted. Upon receiving a shooting operation start command via the system control unit 107, the PTZ control unit 106 starts a sequence at the shooting operation (step S501).

[0074] In step S502, the PTZ control unit 106 determines whether the speed calculated in step S402 falls within a predetermined speed range during acceleration or deceleration. In this example, similar to the first embodiment, it is known in advance that uneven speed occurs in the speed range of "2.5° / sec to 3.5° / sec" in the pan drive unit 102, while there is no speed range in which uneven speed occurs in the tilt drive unit 103. Whether the speed falls within the predetermined speed range during acceleration or deceleration can be determined based on, for example, whether the speed of the constant speed drive is equal to or higher than the lower limit value of the predetermined speed range (2.5° / sec in this example). If the speed falls outside the predetermined speed range during acceleration or deceleration, the process proceeds to step S404. Alternatively, if the speed falls within the predetermined speed range, the process proceeds to step S405.

[0075] In step S503 , the PTZ control unit 106 ends the sequence at the time of the photographing operation.

[0076] As described above, according to the second embodiment, at the time of shooting operation, the current value applied to the drive unit whose speed calculated during acceleration or deceleration falls within the predetermined speed range is set to be greater than the reference current value (current value during normal driving). Similar to the first embodiment, by increasing the current value to be applied, the motor drive torque is increased, so that speed unevenness can be reduced.

[0077] (Third Embodiment)

[0078] The third embodiment will describe another form of change control of the current value applied to the drive unit. More specifically, an example of changing the current value based on whether the speed falls within (passes) a predetermined speed range for a threshold time or more during acceleration / deceleration will be described. Note that the arrangement of the PTZ camera ( Figure 1 , Figure 2A and Figure 2B ) is the same as in the first and second embodiments, so its description will be omitted.

[0079] <Device Operation>

[0080] Figure 6 is a flow chart of the PT control according to the third embodiment. More specifically, Figure 6 1 shows the PT control performed by the PTZ control unit 106. Note that the operations of steps S402, S404 to S406, and S502 are the same as those of the first and second embodiments ( Figure 4 and Figure 5 ) are the same, and description thereof will be omitted. Upon receiving a shooting operation start command via the system control unit 107, the PTZ control unit 106 starts a sequence at the time of the shooting operation (step S601).

[0081] In step S602, the PTZ control unit 106 determines whether the time during which the speed calculated in step S402 falls within the predetermined speed range during acceleration or deceleration is equal to or longer than a threshold time. Similar to the second embodiment, it is assumed that in the panning drive unit 102, the predetermined speed range is a range of "2.5° / sec to 3.5° / sec". In this case, when t represents the passing time and v represents the speed of the constant speed drive, the passing time t can be given by the following formula:

[0082] t = (3.5-2.5) / acceleration (if v is higher than the upper limit of the predetermined speed range)

[0083] t = (v-2.5) / acceleration (if v falls within the predetermined speed range)

[0084] t=0 (if v is lower than the lower limit of the predetermined speed range)

[0085] Then, if the time during acceleration or deceleration during which the speed calculated in step S402 falls within the predetermined speed range is shorter than the threshold time, the process proceeds to step S404. Alternatively, if the time is equal to or longer than the threshold time, the process proceeds to step S405. For example, the threshold time is set to "1 second". Assuming that Figure 3A As shown, for the speed / acceleration calculated in step S402, the pan acceleration is "0.75° / sec 2 ”, the pitch acceleration is “1° / s 2 ”, the constant speed driving speed of pan is “3° / sec”, and the constant speed driving speed of tilt is “4° / sec”. In this case, the time during which the speed falls within (passes through) the predetermined speed range is “0.67 sec” in the pan driving, and “1 sec” in the tilt driving. Therefore, the processing proceeds to step S404 for the pan driving unit 102, and proceeds to step S405 for the tilt driving unit 103.

[0086] In step S603 , the PTZ control unit 106 ends the sequence at the time of the photographing operation.

[0087] As described above, according to the third embodiment, at the time of shooting operation, during acceleration or deceleration, the current value applied to the drive unit whose calculated speed falls within the predetermined speed range for the threshold time or more is set to be greater than the reference current value (current value at the time of normal driving). Similar to the second embodiment, by increasing the current value to be applied, the motor drive torque is increased, so that speed unevenness can be reduced.

[0088] In addition, if the speed passes through the predetermined speed range under large acceleration, the passing time is short, and even if uneven speed occurs, it is not obvious in the video. Therefore, the current value applied to the drive unit can be maintained at the reference current value (current value during normal driving).

[0089] Note that the operation of the third embodiment can be combined with the operation of the first embodiment. That is, the current value can be determined by further considering the speed of the constant speed drive. By combining the third embodiment with the first embodiment, a video with reduced uneven speed in both the acceleration / deceleration drive and the constant speed drive can be provided.

[0090] (Fourth embodiment)

[0091] The fourth embodiment will describe another form of change control of the current value applied to the drive unit. More specifically, an example of changing the current value in further consideration of the zoom position (ie, the camera angle of view) will be described. Note that the arrangement of the PTZ camera ( Figure 1 , Figure 2A and Figure 2B ) is the same as in the first embodiment, so its description will be omitted.

[0092] <Device Operation>

[0093] Figure 7 is a flow chart of the PT control according to the fourth embodiment. More specifically, Figure 7 4 shows the PT control performed by the PTZ control unit 106. Note that the operations of steps S402 to S406 are the same as those of the first embodiment ( Figure 4 ) are the same, and description thereof will be omitted. Upon receiving a shooting operation start command via the system control unit 107, the PTZ control unit 106 starts a sequence at the time of the shooting operation (step S701).

[0094] In step S702, the PTZ control unit 106 determines whether the zoom position in the zoom drive unit 104 is on the telephoto side (smaller viewing angle) or on the wide-angle side (larger viewing angle) compared to the predetermined zoom position (predetermined viewing angle). Video blur caused by uneven speed is often not noticeable on the wide-angle side, but noticeable on the telephoto side. Therefore, if it is determined that the zoom position is on the wide-angle side, the process proceeds to step S404. Alternatively, if it is determined that the zoom position is on the telephoto side, the process proceeds to step S405.

[0095] In step S703 , the PTZ control unit 106 ends the sequence at the time of the photographing operation.

[0096] As described above, according to the fourth embodiment, at the time of shooting operation, the current value applied to the drive unit whose calculated speed (speed of constant speed driving) falls within the predetermined speed range is set to be larger than the reference current value (current value at the time of normal driving). However, if the zoom position is on the wide angle side, the current value is set to the reference current value (current value at the time of normal driving) compared with the predetermined zoom position. Since the current value to be applied is set to the reference current value, it is possible to suppress the driving sound or vibration from becoming louder.

[0097] Note that in the above description, binary determination (telephoto side or wide angle side) is performed based on one predetermined zoom position for determining the zoom position, and two current values ​​are set. However, more detailed multi-value determination may be performed to set three or more current values.

[0098] Other embodiments

[0099] The embodiments of the present invention may also be implemented by providing software (program) for performing the functions of the above-described embodiments to a system or device via a network or various storage media, and a computer or a central processing unit (CPU) or a microprocessing unit (MPU) of the system or device reads and executes the program.

[0100] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments.The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A control device for controlling a camera unit capable of changing direction, comprising: A driving unit configured to change the direction of the camera unit; a control unit configured to perform drive control of the drive unit in a case where the direction of the imaging unit is to be changed, Wherein, when the direction of the camera unit is changed and the speed of the drive unit does not fall within a predetermined speed range, the control unit applies a first current value applied during normal driving to the drive unit, and when the direction of the camera unit is changed and the speed of the drive unit falls within the predetermined speed range, the control unit applies a second current value larger than the first current value to the drive unit.

2. The device according to claim 1, wherein: The driving unit includes a pan driving unit configured to move the camera unit in a pan direction and a tilt driving unit configured to move the camera unit in a tilt direction. When the direction of the camera unit is changed to a designated direction, the control unit starts driving the pan drive unit and the tilt drive unit substantially at the same time, and stops driving substantially at the same time, and In a case where the direction of the image pickup unit is changed, the drive control in each of the pan drive unit and the tilt drive unit includes acceleration drive control, constant speed drive control, and deceleration drive control.

3. The device according to claim 2, wherein: The control unit applies the second current value to at least one of the pan drive unit and the tilt drive unit in a case where a speed of the constant speed drive control of the at least one drive unit falls within the predetermined speed range.

4. The apparatus according to claim 3, further comprising a zoom drive unit configured to change the imaging angle of the imaging unit, in, In a case where a photographing angle of view of the photographing unit is greater than a predetermined angle of view, the control unit applies the first current value to the at least one driving unit.

5. The device according to claim 2, wherein: The control unit applies the second current value to at least one of the pan drive unit and the tilt drive unit when a speed during at least one of acceleration drive control and deceleration drive control of the at least one drive unit falls within the predetermined speed range.

6. The device according to claim 5, wherein: The control unit applies the first current value to the at least one driving unit in a case where the time during which the speed of the at least one driving unit falls within the predetermined speed range is shorter than a threshold time.

7. The device according to claim 1, wherein: The predetermined speed range is a speed range in which uneven speed occurs in a case where the first current value is applied to the drive unit to perform driving.

8. The device according to claim 1, wherein: The control unit performs power control such that power consumption of a predetermined functional unit included in the imaging unit or the control device is small, in a case where the second current value is applied to the driving unit.

9. A control method for controlling a control device of a camera unit capable of changing direction, comprising: In a case where the direction of the imaging unit is changed and the speed of the driving unit does not fall within a predetermined speed range, driving is performed by applying a first current value applied during normal driving to the driving unit, and in a case where the direction of the imaging unit is changed and the speed of the driving unit falls within the predetermined speed range, driving is performed by applying a second current value greater than the first current value to the driving unit. 10 . A computer-readable storage medium storing a program for causing a computer to execute the control method according to claim 9 .

11. A computer program product comprising a program for causing a computer to execute the control method according to claim 9.

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