Control device and method for controlling the same

Abstract

To enable more appropriate pan / tilt (PT) drive control.SOLUTION: A control device for controlling an imaging device capable of changing the direction of an imaging part includes a driving part for changing the direction of the imaging part and control means for performing the drive control of the driving part, when changing the direction of the imaging part. The control means applies a first current value applied during normal driving to the driving part, to drive the driving part, when changing the direction of the imaging part and when the speed of the driving part is smaller than the lower limit value of a predetermined speed range or when the speed of the driving part is larger than the upper limit value of the predetermined speed range and applies a second current value larger than the first current value to the driving part, to drive the driving part, when changing the direction of the imaging part and when the speed of the driving part is within the predetermined speed range.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a technique for controlling the attitude of a camera. [Background technology]

[0002] Surveillance systems and video distribution systems use pan-tilt (PT) cameras, which allow you to control the camera and view the video via a network, dedicated lines, remote control, etc. PT cameras have a mechanism that allows them to rotate in the pan direction (horizontal) and tilt direction (vertical), making it possible to change the shooting direction.

[0003] Depending on the mechanical characteristics of the PT drive unit, vibrations and noises may occur due to resonance when driven at a certain speed range, and speed irregularities with small periodic changes in speed may occur. In video distribution, importance is placed on video quality, and quiet and smooth PT drive is required. Patent Document 1 discloses a method of switching the current value according to the operating mode in order to drive the motor from low to high speeds while suppressing vibrations. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-18747 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technique described in Patent Document 1 has a problem in that resonance noise becomes louder because the current value is increased in the high-speed mode.

[0006] The present invention has been made in consideration of such problems, and has an object to provide a technique that enables more appropriate PT drive control. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, a control device according to the present invention has the following configuration. That is, a control device for controlling an imaging device capable of changing the orientation of an imaging unit includes: A drive unit for changing the orientation of the imaging unit; a control unit that controls the driving of the driving unit when changing the orientation of the imaging unit; having When changing the orientation of the imaging unit, if the speed of the drive unit is smaller than the lower limit of a predetermined speed range or if the speed of the drive unit is greater than the upper limit of the predetermined speed range, the control means drives the drive unit by applying a first current value that is applied during normal driving, and when changing the orientation of the imaging unit, if the speed of the drive unit falls within the predetermined speed range, the control means drives the drive unit by applying a second current value greater than the first current value. Effect of the Invention

[0008] According to the present invention, it is possible to provide a technique that enables more appropriate PT drive control. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing functional blocks of the PTZ camera. [Diagram 2] 2A and 2B are diagrams illustrating the mechanical configuration and movable range of a PTZ camera. [Diagram 3] FIG. 13 is a diagram showing acceleration / deceleration control during a shot operation. [Figure 4] 4 is a flowchart of PT control (first embodiment). [Diagram 5] 11 is a flowchart of PT control (second embodiment). [Figure 6] 13 is a flowchart of PT control (third embodiment). [Figure 7] 13 is a flowchart of PT control (fourth embodiment). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0011] (First embodiment) As a first embodiment of a control device according to the present invention, the following will explain an example of change control of a current value applied to a driving unit of a pan-tilt-zoom (PTZ) camera.

[0012] <Device configuration> 1 is a diagram showing functional blocks of a PTZ camera 100. The PTZ camera 100 is connected to a client device (information processing device) (not shown) via a network 150 in a state in which they can communicate with each other. A user can transmit various camera control commands to the PTZ camera 100 via the client device.

[0013] The PTZ camera 100 includes an imaging unit 101, a pan driving unit 102, a tilt driving unit 103, a zoom driving unit 104, an image processing unit 105, a PTZ control unit 106, a system control unit 107, and a communication unit .

[0014] The imaging unit 101 is composed of imaging lenses including a focus lens, a zoom lens, and an imaging element, as well as a mechanical drive system and circuits that drive them. The imaging lens forms an image of a subject on the imaging element, and the imaging element generates an electrical signal that represents the subject image.

[0015] The pan driving unit 102 is composed of a mechanical driving system that performs panning, a driving motor, a motor driver, etc., and is controlled by a PTZ control unit 106. The PTZ control unit 106 sets the driving amount, speed, acceleration, driving current, etc. to the pan driving unit 102, and driving is started by a driving start command. A detailed configuration will be described later with reference to FIG.

[0016] The tilt driving unit 103 is composed of a mechanical driving system that performs tilting operation, a driving motor, a motor driver, etc., and is controlled by the PTZ control unit 106. The PTZ control unit 106 sets the driving amount, speed, acceleration, driving current, etc. to the tilt driving unit 103, and driving is started by a drive start command. The detailed configuration will be described later with reference to FIG.

[0017] 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 composed of a mechanical driving system that performs zooming, a driving motor, a motor driver, etc., and is controlled by a PTZ control unit 106.

[0018] The image processing unit 105 performs predetermined development processing, compression encoding processing, and the like 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. Furthermore, when an instruction to adjust the image quality is received from the system control unit 107, the image processing unit 105 adjusts the image quality.

[0019] The PTZ control unit 106 processes instructions related to PTZ control received from the system control unit 107. For example, based on a pan / tilt instruction received from the system control unit 107, the PTZ control unit 106 controls the driving amount, speed, acceleration / deceleration of the pan driving unit 102 and the tilt driving unit 103, and performs an initialization operation. Based on a zoom instruction received from the system control unit 107, the PTZ control unit 106 controls the driving amount, speed, acceleration / deceleration of the zoom driving unit 104, and performs an initialization operation. The PTZ control unit 106 may be implemented in a form of software implemented by a CPU executing a program, or in a form of hardware implemented in an application specific integrated circuit (ASIC) or the like. Also, the PTZ control unit 106 may be implemented by combining software implementation and hardware implementation.

[0020] The system control unit 107 controls the entire PTZ camera 100. The system control unit 107 also distributes image data generated by the image processing unit 105 to a client device (not shown) via the communication unit 108. The system control unit 107 also analyzes a camera control command transmitted from a client device (not shown) via the communication unit 108 and performs processing according to the command. For example, the system control unit 107 instructs the image processing unit 105 to adjust image quality, and instructs the PTZ control unit 106 to perform a PTZ operation or a shot operation. The system control unit 107 may be implemented in software by a CPU executing a program, or may be implemented in hardware such as an application specific integrated circuit (ASIC). The system control unit 107 may also be implemented by combining software and hardware.

[0021] A communication unit 108 receives a camera control command transmitted from a client device, and transmits it to a system control unit 107. In addition, 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).

[0022] It should be noted that the PTZ camera 100 in this embodiment is not limited to the configuration shown in Fig. 1. For example, the PTZ camera 100 may be provided with a video output terminal such as an SDI (Serial Digital Interface) or an HDMI (High-Definition Multimedia Interface) (registered trademark), an audio input / output unit, or an external device input / output unit. The communication unit 108 may be connected either wired or wirelessly. Furthermore, instead of being connected to the network 150, the communication unit 108 may be connected to another device via serial communication or the like.

[0023] Fig. 2 is a diagram explaining the mechanical configuration and movable range of the PTZ camera 100. Fig. 2(a) is a diagram showing the attached PTZ camera 100 as viewed from above (tilt is "+90 degrees"). Fig. 2(b) is a diagram showing the PTZ camera 100 as viewed from the side when installed upright. In Fig. 2, the PTZ camera 100 is composed of a bottom case 201, a turntable 202, a camera head support 203, and a camera head 204.

[0024] In the following, the operation of the PT movable part will be described by defining the vertical axis of the PTZ camera 100 as the vertical axis and the axis perpendicular to this as the horizontal axis. In Fig. 2(a), the clockwise direction around the vertical axis perpendicular to the paper surface is the positive (plus) direction of the pan angle, and the counterclockwise direction is the negative (minus) direction of the pan angle. In Fig. 2(b), the clockwise direction around the axis perpendicular to the paper surface is the positive direction of the tilt angle, and the counterclockwise direction is the negative direction of the tilt angle.

[0025] The pan driving unit 102 is composed of a bottom case 201 and a turntable 202, and the turntable 202 rotates in the horizontal direction around a vertical axis. The pan driving unit 102 of this embodiment can rotate in the pan direction from "-170 degrees" to "+170 degrees" around a given reference direction (0 degrees).

[0026] Tilt driving unit 103 is composed of camera head support 203 and camera head 204 provided on turntable 202, and camera head 204 rotates vertically around a horizontal axis. When tilt driving unit 103 of this embodiment is installed upright as shown in Fig. 2(b), it can rotate from "-30 degrees" diagonally downward to "+100 degrees" diagonally upward with respect to the horizontal direction (0 degrees).

[0027] 2(a)-(b) show angles that the user can instruct the PTZ camera 100 to have, and the PTZ control unit 106 issues a drive instruction to the pan driving unit 102 or the tilt driving unit 103 based on the angle shown in FIG. 2. In this way, the PTZ camera 100 of this embodiment can change the shooting direction by rotating the orientation of the camera head 204 in the pan direction and tilt direction, and can shoot a wide range. Note that the PTZ camera 100 is not limited to the configuration shown in FIG. 2. For example, the PTZ camera 100 may be capable of 360 degrees (endless) driving in the pan direction and / or tilt direction.

[0028] <Shot action> The shot operation is a control operation for performing PT drive so that pan drive and tilt drive are started and stopped approximately simultaneously when changing the camera attitude (shooting direction). Note that the same control may be performed for zoom drive.

[0029] Fig. 3 is a diagram showing acceleration / deceleration control during a shot operation. Fig. 3(a) is a graph showing the change in speed of each of the pan driver 102 and the tilt driver 103 during a shot operation. Fig. 3(b) is a diagram showing the relationship between the pan movement amount and the tilt movement amount.

[0030] In Fig. 3(a), the horizontal axis indicates time, the vertical axis indicates speed, the solid line indicates pan speed, and the dashed line indicates tilt speed. Specifically, the pan driving unit 102 and the tilt driving unit 103 start driving at approximately the same time at "0 seconds", perform acceleration driving control for 4 seconds, go through constant speed driving control, perform deceleration driving control for 4 seconds, and stop driving at approximately the same time at "14 seconds". During the constant speed driving period, the pan driving unit 102 performs constant speed driving at "3 degrees / second", and the tilt driving unit 103 performs constant speed driving at "4 degrees / second". The movement amount of the pan driving unit 102 is "30 degrees", and the movement amount of the tilt driving unit 103 is "40 degrees".

[0031] In FIG. 3(b), the horizontal axis indicates the pan movement amount and the vertical axis indicates the tilt movement amount, and shows the relationship between the pan movement amount and the tilt movement amount when driven at the speed shown in FIG. 3(a). In FIG. 3(b), the ratio between the pan movement amount and the tilt movement amount is constant (the graph is a straight line), which shows that the relationship between the pan movement amount and the tilt movement amount is linear (linear drive). When driven linearly, the shooting direction of the camera moves linearly. On the other hand, for example, if the acceleration / deceleration times of the pan drive unit 102 and the tilt drive unit 103 are different, the graph will not be a straight line and linear drive will not be achieved.

[0032] To perform a shot operation, the PTZ control unit 106 must register in advance the target positions of the pan driving unit 102, tilt driving unit 103, and zoom driving unit 104. For example, the target position is registered as "shot 1." Here, it is assumed that "shot 1" has a pan position of "30 degrees," a tilt position of "40 degrees," and a zoom position of "telephoto end position." Here, it is assumed that a shot operation is performed by specifying a movement speed or a movement time.

[0033] Consider a case where the current position is a pan position of "0 degrees", a tilt position of "0 degrees", and a zoom position of "telephoto end position", and a movement time of "14 seconds" is specified to move to the position of "shot 1". In this case, the PTZ control unit 106 calculates the pan movement amount to "30 degrees", the tilt movement amount to "40 degrees", and the zoom movement amount to "0 (no movement)".

[0034] In order to stop pan driving and tilt driving 14 seconds after starting, the PTZ control unit 106 calculates and sets the speed and acceleration of each driving unit. As shown in Fig. 3(a), the movement time is t, the acceleration time is ta, the deceleration time is td, and the constant speed driving speed is v. In this case, the movement amount x can be expressed by the following formula (1) based on the method for calculating the area of ​​a trapezoid.

[0035]

number

[0036] Therefore, the velocity v can be calculated by the following formula (2), which is a modification of formula (1).

[0037]

number

[0038] Assume that the acceleration time (ta) is "4 seconds" and the deceleration time (td) is "4 seconds." In this case, in order to drive a pan movement of "30 degrees" in 14 seconds, the pan constant speed drive speed is calculated to be "3 degrees / second." Similarly, in order to drive a tilt movement of "40 degrees" in 14 seconds, the tilt constant speed drive speed is calculated to be "4 degrees / second."

[0039] Also, when moving to the position of "shot 1" by specifying the moving speed instead of the moving time, v is known in formula (1). Therefore, the moving time t can be calculated by the following formula (3).

[0040]

number

[0041] The movement time of each moving part is calculated using formula (3), and the longest calculated movement time is set as the movement time during the shot operation. Then, the speed is calculated using formula (2) so that the other moving parts can move within the set movement time.

[0042] Consider the case where the current position is pan position "0 degrees", tilt position "0 degrees", and zoom position "telephoto end position", and a movement speed of "4 degrees / second" is specified to move to the position of "shot 1". In this case, when the movement time of each drive unit is calculated using formula (3), the movement time of the tilt drive is "14 seconds", which is the longest. Therefore, the movement time during the shot operation is set to "14 seconds". In addition, the tilt drive speed is the specified "4 degrees / second". The pan drive speed can be calculated using formula (2) with a movement time of "14 seconds" to be "3 degrees / second". Since the speed and acceleration time are known, the acceleration can be calculated by dividing the speed by the acceleration time.

[0043] The PTZ control unit 106 sets the speed and acceleration thus determined in the pan driving unit 102 and the tilt driving unit 103, thereby making it possible to realize a shot operation.

[0044] <Device Operation> As explained in the Background Art section, depending on the mechanical characteristics of the PT drive unit, when driven at a speed within a specified speed range, vibrations and noise may occur due to resonance, and speed irregularities with small periodic changes in speed may occur. As mentioned above, the speed and acceleration of the shot operation can be calculated, but depending on the specified value (movement speed or movement time), the calculated speed will be included in the above-mentioned specified speed range.

[0045] Therefore, in the first embodiment, when the calculated speed is within the above-mentioned predetermined speed range, the current value applied to each drive unit is increased to perform PT drive. Increasing the current value increases the torque of the drive unit, improving the holding force on the imaging unit 101 (making it harder for the imaging unit 101 to move). Therefore, even when PT drive is performed at a speed within the above-mentioned predetermined speed range, it is possible to reduce the occurrence of vibrations and uneven speed.

[0046] Increasing the current value may increase the torque of the drive unit and the resonance noise. However, the speed range in which the speed unevenness occurs and the speed range in which the resonance noise occurs are often different speed ranges, so increasing the current value in the speed range in which the speed unevenness occurs has little effect on the resonance noise.

[0047] 4 is a flowchart of the PT control in the first embodiment. Specifically, it shows the PT control executed by the PTZ control unit 106. When the PTZ control unit 106 receives a shot operation start command via the system control unit 107, it starts a sequence for the shot operation (S401).

[0048] In S402, the PTZ control unit 106 accepts designation of a target position and movement time of the PT in a shot operation. For example, the designation is accepted via the communication unit 108 and the system control unit 107 from a client device (not shown) operated by a user. The PTZ control unit 106 also acquires the current position of the PT. Then, the PTZ control unit 106 calculates the movement amount of each driving unit from the current position and the target position, and calculates the speed and acceleration of each driving unit from the designated movement time.

[0049] As described above, when a moving speed is specified instead of a moving time, the moving time of each driving unit is calculated at the specified moving speed, and the longest time is set as the moving time. For example, the moving speed of either pan or tilt, whichever has the longer moving distance, is accepted from the user, and at this time, it is preferable to prevent the moving speed from falling within the resonance speed range. Then, the speed and acceleration of each driving unit are calculated using the set moving time.

[0050] In S403, the PTZ control unit 106 judges whether the speed calculated in S402 (constant speed drive speed) is within a predetermined speed range. For example, it is assumed that it is known in advance that the speed range of "2.5 degrees / sec to 3.5 degrees / sec" causes speed unevenness in the pan drive unit 102, and that there is no speed range in which speed unevenness occurs in the tilt drive unit 103. In this case, "2.5 degrees / sec to 3.5 degrees / sec" is used as the predetermined speed range only in the pan drive unit 102. If the speed of the pan drive unit 102 calculated in S402 is not within the predetermined speed range, proceed to S404, and if it is within the predetermined speed range, proceed to S405. In other words, if the speed calculated in S402 (constant speed drive speed) is greater than the upper limit of the predetermined speed range or less than the lower limit of the predetermined speed range, proceed to S404.

[0051] Although it is assumed here that there is a speed range in which speed unevenness occurs only in the pan driving unit 102, a predetermined speed range may also be set in the tilt driving unit 103 for determination.

[0052] In S404, the PTZ control unit 106 sets the current to be applied to the drive unit (the pan drive unit 102 or the tilt drive unit 103) to "12", which is current value 1 (I1). Here, the current value is a value between 0 and 31, and the larger the value, the larger the current value. Note that current value 1 is the standard current value (during normal driving) set at the time of startup.

[0053] In S405, the PTZ control unit 106 sets the current to be applied to the drive unit (pan drive unit 102 or tilt drive unit 103) determined in S403 to be within the predetermined speed range to "16", which is current value 2 (I2). Note that current value 2 is a higher set value (i.e., a larger current value) than current value 1. This increases the motor drive torque of the drive unit (pan drive unit 102 and / or tilt drive unit 103), making it possible to reduce speed unevenness.

[0054] In S406, the PTZ control unit 106 starts driving the pan driving unit 102 and tilt driving unit 103 (and zoom driving unit 104) at the speed and acceleration calculated in S402 and the current value set in S404 and / or S405. Here, each driving unit is driven at the speed shown in FIG. 3(a). At that time, the pan driving unit 102 is driven at a current value of "16", and the tilt driving unit 103 is driven at a current value of "12".

[0055] In S407, the PTZ control unit 106 ends the sequence during the shot operation.

[0056] As described above, according to the first embodiment, during a shot operation, the current value applied to the drive unit when the calculated speed (constant speed drive speed) is within a predetermined speed range is made larger than the reference current value (normal drive). By making the applied current value larger, it becomes possible to increase the motor drive torque and reduce speed unevenness. Furthermore, when the calculated speed is not within the predetermined speed range, the applied current value is set to the reference current value (normal drive), so that drive noise and vibration do not increase. Furthermore, there is an advantage in that the quality of the obtained image is improved because linear drive is possible during the shot operation.

[0057] In the above description, the current value setting is changed by determining whether the calculated speed is within a predetermined speed range, but it is also possible to store the speed and current value settings in a table or the like in advance and change the current value setting by reading out the table value. Also, in the above description, it is described that the current value is increased over the entire drive control period for a drive unit whose calculated speed is within a predetermined speed range, but it is also possible to increase the current value only during the period when the calculated speed is within the predetermined speed range.

[0058] Furthermore, increasing the current value increases the power consumption of the entire imaging device 100. Therefore, when the current value applied to the drive unit is increased, power control may be performed so that the power consumption of other functional units (other drive systems, etc.) is reduced. For example, the power supply to unused functional units may be stopped.

[0059] Second embodiment In the second embodiment, another form of change control of the current value applied to the driving unit will be described. More specifically, an example will be described in which the current value is changed based on whether or not the vehicle enters (passes) a predetermined speed range during acceleration / deceleration. Note that the configuration of the PTZ camera (FIGS. 1 and 2) is the same as that of the first embodiment, so the description will be omitted.

[0060] <Device Operation> 5 is a flowchart of the PT control in the second embodiment. Specifically, it shows the PT control executed by the PTZ control unit 106. Note that S402 and S404 to S406 are similar to the operations of the same reference numerals in the first embodiment (FIG. 4), and therefore the explanation will be omitted. When the PTZ control unit 106 receives a shot operation start command via the system control unit 107, it starts the sequence for the shot operation (S501).

[0061] In S502, the PTZ control unit 106 judges whether or not the speed calculated in S402 falls within a predetermined speed range during acceleration or deceleration. Here, as in the first embodiment, it is assumed that it is known in advance that in the pan driving unit 102, speed unevenness occurs in the speed range of "2.5 degrees / sec to 3.5 degrees / sec", and that in the tilt driving unit 103, there is no speed range in which speed unevenness occurs. Whether or not the speed during acceleration or deceleration falls within the predetermined speed range can be judged, for example, by whether or not the constant speed driving speed is equal to or greater than the lower limit of the predetermined speed range (here, 2.5 degrees / sec). If the speed during acceleration or deceleration does not fall within the predetermined speed range, the process proceeds to S404, and if it falls within the predetermined speed range, the process proceeds to S405.

[0062] In S503, the PTZ control unit 106 ends the sequence during the shot operation.

[0063] As described above, according to the second embodiment, during a shot operation, the current value applied to the drive unit when the calculated speed falls within a predetermined speed range during acceleration or deceleration is made larger than the reference current value (during normal driving). As a result, as in the first embodiment, by increasing the applied current value, the motor drive torque increases, making it possible to reduce speed unevenness.

[0064] Third embodiment In the third embodiment, another form of change control of the current value applied to the driving unit will be described. More specifically, an example will be described in which the current value is changed based on whether or not the vehicle is in (passing through) a predetermined speed range for a threshold time or more during acceleration / deceleration. Note that the configuration of the PTZ camera (FIGS. 1 and 2) is the same as in the first and second embodiments, so the description will be omitted.

[0065] <Device Operation> 6 is a flowchart of the PT control in the third embodiment. Specifically, it shows the PT control executed by the PTZ control unit 106. Note that S402, S404 to S406, and S502 are similar to the operations of the same reference numerals in the first and second embodiments (FIGS. 4 and 5), and therefore the explanation will be omitted. When the PTZ control unit 106 receives a shot operation start command via the system control unit 107, it starts the sequence for the shot operation (S601).

[0066] In S602, the PTZ control unit 106 judges whether the time during which the speed calculated in S402 is within a predetermined speed range during acceleration or deceleration is equal to or longer than a threshold time. Here, as in the second embodiment, it is assumed that the predetermined speed range in the pan driving unit 102 is "2.5 degrees / second to 3.5 degrees / second." In this case, assuming that the passing time is t and the constant speed driving speed is v, it can be calculated as follows:

[0067] t=(3.5-2.5) / acceleration (when v is greater than the upper limit of the speed range) t=(v-2.5) / acceleration (where v is within a given velocity range) t=0 (when v is less than the lower limit of the speed range)

[0068] If the time during which the speed calculated in S402 is within the predetermined speed range during acceleration or deceleration is less than the threshold time, the process proceeds to S404, and if the time is equal to or greater than the threshold time, the process proceeds to S405. For example, the threshold time is set to "1 second." As shown in FIG. 3(a), the speed / acceleration calculated in S402 is set to "0.75 degrees / second^2" for pan acceleration, "1 degree / second^2" for tilt acceleration, "3 degrees / second" for pan constant speed drive speed, and "4 degrees / second" for tilt constant speed drive speed. In this case, the time during which the speed is within (passes through) the predetermined speed range is "0.67 seconds" for pan drive and "1 second" for tilt drive. Therefore, the process proceeds to S404 for the pan drive unit 102, and to S405 for the tilt drive unit 103.

[0069] In S603, the PTZ control unit 106 ends the sequence during the shot operation.

[0070] As described above, according to the third embodiment, during a shot operation, the current value applied to the drive unit when the calculated speed is within a predetermined speed range for a threshold time or more during acceleration or deceleration is made larger than the reference current value (during normal driving). As a result, as in the second embodiment, by increasing the applied current value, the motor drive torque increases and it becomes possible to reduce speed unevenness.

[0071] Furthermore, when passing through a specified speed range at large acceleration, the passing time is short and even if speed unevenness occurs, it is not noticeable in the image, so the current value applied to the drive unit can remain the standard current value (during normal driving).

[0072] The operation of the third embodiment may be combined with the operation of the first embodiment. That is, the current value may be determined taking into consideration the speed of constant speed driving as well. By combining with the first embodiment, it is possible to provide an image with reduced speed unevenness during both acceleration / deceleration driving and constant speed driving.

[0073] (Fourth embodiment) In the fourth embodiment, another form of control for changing the current value applied to the driving unit will be described. More specifically, an example in which the current value is changed by further considering the zoom position (i.e., the shooting angle of view) will be described. Note that the configuration of the PTZ camera (FIGS. 1 and 2) is the same as that of the first embodiment, so the description will be omitted.

[0074] <Device Operation> Fig. 7 is a flowchart of the PT control in the fourth embodiment. Specifically, it shows the PT control executed by the PTZ control unit 106. Note that S402 to S406 are similar to the operations of the same reference numerals in the first embodiment (Fig. 4), and therefore the explanation will be omitted. When the PTZ control unit 106 receives a shot operation start command via the system control unit 107, it starts the sequence for the shot operation (S701).

[0075] In S702, the PTZ control unit 106 compares the zoom position of the zoom driving unit 104 with a predetermined zoom position (predetermined angle of view) and determines whether it is on the telephoto side (narrow shooting angle of view) or the wide side (wide shooting angle of view). Image blur caused by speed unevenness tends to be less noticeable on the wide side and more noticeable on the telephoto side. Therefore, if it is determined to be on the wide side, proceed to S404, and if it is determined to be on the telephoto side, proceed to S405.

[0076] In S703, the PTZ control unit 106 ends the sequence during the shot operation.

[0077] As described above, according to the fourth embodiment, during a shot operation, the current value applied to the drive unit when the calculated speed (constant speed drive speed) is within a predetermined speed range is made larger than the reference current value (normal drive). However, when the zoom position is on the wide side compared to the predetermined zoom position, the reference current value (normal drive) is used. This makes it possible to prevent the drive noise and vibration from increasing because the applied current value is the reference current value.

[0078] In the above explanation, the zoom position is judged based on one specified zoom position and a binary judgment (telephoto side or wide side) is made to set two current values, but it is also possible to configure the system to make a more detailed multi-value judgment and set three or more current values.

[0079] The disclosure of this specification includes the following control device, control method, and program. (Item 1) A control device for controlling an imaging device capable of changing the orientation of an imaging unit, A drive unit for changing the orientation of the imaging unit; a control unit that controls the driving of the driving unit when changing the orientation of the imaging unit; having When changing the orientation of the imaging unit, if the speed of the drive unit is lower than a lower limit of a predetermined speed range or if the speed of the drive unit is higher than an upper limit of the predetermined speed range, the control means applies to the drive unit a first current value that is applied during normal driving, and when changing the orientation of the imaging unit, if the speed of the drive unit falls within the predetermined speed range, the control means applies to the drive unit a second current value that is higher than the first current value, and drives the drive unit. A control device comprising: (Item 2) The drive unit includes a pan drive unit that moves the orientation of the imaging unit in a pan direction and a tilt drive unit that moves the orientation of the imaging unit in a tilt direction, the control means performs control to start driving the pan driving unit and the tilt driving unit substantially simultaneously and stop driving the pan driving unit and the tilt driving unit substantially simultaneously when changing the orientation of the imaging unit to a specified orientation; The drive control in each of the pan drive unit and the tilt drive unit when changing the orientation of the imaging unit includes acceleration drive control, constant speed drive control, and deceleration drive control. 2. The control device according to item 1, (Item 3) When a speed of the constant speed drive control in at least one of the pan drive unit and the tilt drive unit falls within the predetermined speed range, the control means applies the second current value to the at least one of the drive units to drive the at least one of the pan drive unit and the tilt drive unit. 3. The control device according to item 2, (Item 4) The imaging device further includes a zoom driver for changing an imaging angle of view of the imaging unit. The control means applies the first current value to the at least one driving section to drive the at least one driving section when the imaging angle of view of the imaging section is wider than a predetermined angle of view. 4. The control device according to item 3, (Item 5) When a speed during at least one of the periods of the acceleration drive control and the deceleration drive control in at least one of the pan drive unit and the tilt drive unit falls within the predetermined speed range, the control means applies the second current value to the at least one of the drive units to drive the at least one of the pan drive unit and the tilt drive unit. 5. The control device according to any one of items 2 to 4, (Item 6) The control means applies the first current value to the at least one driving unit to drive the at least one driving unit when the time during which the speed of the at least one driving unit is within the predetermined speed range is less than a threshold time. 6. The control device according to item 5, characterized in that (Item 7) The predetermined speed range is a speed range in which speed unevenness occurs when the drive unit is driven by applying the first current value to the drive unit. 7. The control device according to any one of items 1 to 6, (Item 8) The control device further includes a power control unit that performs power control such that power consumption in a predetermined functional unit included in the imaging device or the control device is reduced when the control unit applies the second current value to the driving unit to drive the driving unit. 8. The control device according to any one of items 1 to 7, (Item 9) A method for controlling an imaging device having a drive unit that changes the orientation of an imaging unit and capable of changing the orientation of the imaging unit, comprising: The method includes a control step of applying a first current value to the drive unit during normal driving to drive the drive unit when the speed of the drive unit is lower than a lower limit of a predetermined speed range or higher than an upper limit of the predetermined speed range when changing the orientation of the imaging unit, and applying a second current value higher than the first current value to the drive unit when the speed of the drive unit falls within the predetermined speed range when changing the orientation of the imaging unit. A control method comprising: (Item 10) A program for causing a computer to execute the control method described in item 9.

[0080] (Other Examples) The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0081] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0082] 100 imaging device; 101 imaging section; 102 pan driving section; 103 tilt driving section; 104 zoom driving section; 105 image processing section; 106 PTZ control section; 107 system control section; 108 communication section

Claims

1. A control device for controlling an imaging device capable of changing the orientation of an imaging unit, A drive unit for changing the orientation of the imaging unit; a control unit that controls the driving of the driving unit when changing the orientation of the imaging unit; having When changing the orientation of the imaging unit, if the speed of the drive unit is lower than the lower limit of a predetermined speed range or higher than the upper limit of the predetermined speed range, the control means drives the drive unit by applying a first current value that is applied during normal driving to the drive unit, and when changing the orientation of the imaging unit, if the speed of the drive unit falls within the predetermined speed range, the control means drives the drive unit by applying a second current value that is higher than the first current value to the drive unit. A control device comprising:

2. The drive unit includes a pan drive unit that moves the orientation of the imaging unit in a pan direction and a tilt drive unit that moves the orientation of the imaging unit in a tilt direction, the control means performs control to start driving the pan driving unit and the tilt driving unit substantially simultaneously and stop driving the pan driving unit and the tilt driving unit substantially simultaneously when changing the orientation of the imaging unit to a specified orientation; The drive control in each of the pan drive unit and the tilt drive unit when changing the orientation of the imaging unit includes acceleration drive control, constant speed drive control, and deceleration drive control. The control device according to claim 1 .

3. When a speed of the constant speed drive control in at least one of the pan drive unit and the tilt drive unit falls within the predetermined speed range, the control unit applies the second current value to the at least one of the drive units to drive the at least one of the pan drive unit and the tilt drive unit.

3. The control device according to claim 2.

4. The imaging device further includes a zoom driver for changing an imaging angle of view of the imaging unit. The control means applies the first current value to the at least one driving section to drive the at least one driving section when the imaging angle of the imaging section is wider than a predetermined angle of view.

4. The control device according to claim 3.

5. When a speed during at least one of the periods of the acceleration drive control and the deceleration drive control in at least one of the pan drive unit and the tilt drive unit falls within the predetermined speed range, the control means applies the second current value to the at least one of the drive units to drive the at least one of the pan drive unit and the tilt drive unit.

3. The control device according to claim 2.

6. The control means applies the first current value to the at least one driving unit to drive the at least one driving unit when the time during which the speed of the at least one driving unit is within the predetermined speed range is less than a threshold time.

6. The control device according to claim 5.

7. The predetermined speed range is a speed range in which speed unevenness occurs when the drive unit is driven by applying the first current value to the drive unit. The control device according to claim 1 .

8. The control device further includes a power control unit that performs power control such that power consumption in a predetermined functional unit included in the imaging device or the control device is reduced when the control unit applies the second current value to the driving unit to drive the driving unit. The control device according to claim 1 .

9. A method for controlling an imaging device having a drive unit that changes the orientation of an imaging unit and capable of changing the orientation of the imaging unit, comprising: The method includes a control step of applying a first current value to the drive unit during normal driving to drive the drive unit when the speed of the drive unit is lower than a lower limit of a predetermined speed range or higher than an upper limit of the predetermined speed range when changing the orientation of the imaging unit, and applying a second current value higher than the first current value to the drive unit when the speed of the drive unit falls within the predetermined speed range when changing the orientation of the imaging unit. A control method comprising:

10. A program for causing a computer to execute the control method according to claim 9.

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