Imaging device, method for controlling the drive of the imaging device

Abstract

It uses a simple structure to maintain a constant field of view with low power consumption. [Solution] The static holding current applied when the pan shaft motor 43 and tilt shaft motor 45 are stopped is also generated by the pan shaft driver 42 and tilt shaft driver 44, respectively. The setting of this static holding current is also performed by the drive control unit 41, which sets the static holding current for the pan shaft motor 43 based on the wind pressure recognized by the wind pressure sensors 61A and 61B, and sets the static holding current for the tilt shaft motor 45 based on the wind pressure recognized by the wind pressure sensors 62A and 62B. This setting is performed so that the static holding current is increased when the torque due to the recognized wind pressure is large, and the static holding current is decreased when the torque is small.

Description

Technical Field

[0001] The present invention relates to an imaging device in which viewing direction control is performed based on a fixed pan head, and a drive control method therefor. Background Art

[0002] An imaging device used for monitoring is fixedly used in various places such as roads and stations, and is configured so that the video thereof can be checked at a remote location. In this imaging device, the main body (imaging unit) that actually performs imaging is mounted on a pan head fixed at the installation location, and the viewing direction of imaging is controlled by controlling the angle of the main body relative to the pan head. For this reason, the imaging unit is mounted on the pan head via a rotating shaft, the aforementioned angle is determined by the rotation angle of the rotating shaft, and this operation is generally controlled from a remote location. Such viewing direction control is performed for each of an angle within a horizontal plane (pan angle) and an angle within a vertical plane (tilt angle). For this purpose, a rotating shaft for pan angle control and a rotating shaft for tilt angle control are respectively provided, and each rotating shaft is driven by a motor. That is, the viewing direction is adjusted by controlling these rotating shafts.

[0003] However, particularly in monitoring imaging devices, the period during which the motor is driven to adjust the viewing direction as described above is actually very short, and the viewing direction is fixed constant during most of the time. Conversely, during the period when the viewing direction should be kept constant, it is necessary to suppress rotation of the rotating shaft caused by external force (torque). Such external force actually increases due to weather conditions such as wind, which may cause unintended changes in the viewing direction. For this reason, for example, as described in Patent Document 1, a brake (e.g., a non-excitation brake) is mounted on the motor that drives the rotating shaft. During the period when the viewing direction should be kept constant, driving the non-excitation brake suppresses rotation of the rotating shaft, thereby suppressing unintended changes in the viewing direction.

[0004] Furthermore, a stepping motor, in which the rotation angle of the rotating shaft is controlled by pulse drive, is particularly preferred for driving the aforementioned rotating shaft. In a stepping motor, current flows even when stopped, thereby providing a self-holding force that maintains the angle of the rotating shaft even when an external force is applied, and this self-holding force suppresses unintended changes in the direction of view. In other words, by maintaining this self-holding force by flowing current, the direction of view when stopped is controlled to be constant without the need for brakes. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2010-130061 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0006] In the surveillance imaging devices described above, rechargeable batteries are often used as their power source. In this case, in order to ensure stable monitoring, it is necessary to reduce the power consumption of the imaging device and extend the time for which power can be supplied from the rechargeable battery.

[0007] In contrast, as described above, stabilizing the field of view direction using the self-holding force of the stepping motor required power consumption to maintain the field of view direction even when the stepping motor was not being driven. In other words, in the imaging device described above, power was required not only when changing the field of view direction but also to maintain a constant field of view direction, resulting in high power consumption.

[0008] For example, it is possible to attach a mechanical brake to the rotating shaft and suppress its rotation by friction without supplying power. However, in this case, the device becomes larger in order to attach the mechanical brake, and in imaging devices that have both a rotating shaft for pan angle control and a rotating shaft for tilt angle control, the device becomes larger. Furthermore, mechanical brakes have problems such as their operation becoming unstable in the face of environmental changes such as strong winds and rain.

[0009] Therefore, there was a need for an imaging device that could maintain a constant field of view direction with a simple structure and low power consumption.

[0010] This invention has been made in view of these circumstances and aims to solve the above-mentioned problems. [Means for solving the problem]

[0011] The present invention relates to an imaging device in which the direction of the field of view of an imaging unit that performs imaging is adjusted by the rotation of a rotation axis with respect to a pan / tilt head on which the imaging unit is mounted, comprising: a motor that drives the rotation axis and, when the rotation axis is not driven, maintains a state in which the rotation axis is stopped against external forces by flowing a static holding current; a wind pressure sensor installed in a component driven by the rotation axis at a location spaced apart from the rotation axis in a plan view perpendicular to the rotation axis, and detecting wind pressure at that location; and a drive control unit that calculates the torque applied around the rotation axis from the wind pressure recognized by the wind pressure sensor, sets the static holding current to be large when the absolute value of the torque is large, and sets the static holding current to be small when the absolute value of the torque is small, and controls the motor when the rotation axis is not driven. The aforementioned component may include two wind pressure sensors located at points spaced apart from each other in the longitudinal direction. The two wind pressure sensors may be installed in symmetrical positions with respect to the rotation axis in the plan view. A rechargeable battery may be used as the power source. Furthermore, the present invention relates to a drive control method for an imaging device in which the direction of the field of view of an imaging unit that performs imaging is adjusted by the rotation of a rotation axis with respect to a pan / tilt head on which the imaging unit is mounted, and includes a motor that drives the rotation axis and, when the rotation axis is not driven, maintains a state in which the rotation axis is stopped against external forces by flowing a static holding current, and a wind pressure sensor installed in a component driven by the rotation axis at a location spaced apart from the rotation axis in a plan view perpendicular to the rotation axis, and detecting wind pressure at that location, and the torque applied around the rotation axis is calculated from the wind pressure recognized by the wind pressure sensor, and the static holding current is set to be large when the absolute value of the torque is large, and to be set to be small when the absolute value of the torque is small, thereby controlling the motor when the rotation axis is not driven. [Effects of the Invention]

[0012] According to the present invention, a simple structure can be used to maintain a constant field of view with low power consumption. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view of the external appearance of the imaging device according to the embodiment. [Figure 2] This is a schematic diagram showing the imaging device according to the embodiment as viewed from above (a) and from the side (b). [Figure 3] This figure shows an example of the wind pressure measured in the imaging device according to the embodiment, and the torque applied to the rotating shaft by this wind pressure. [Figure 4] This diagram shows the configuration of the imaging device according to the embodiment. [Figure 5] This is a flowchart showing the operation of the drive control unit in the imaging device according to the embodiment. [Modes for carrying out the invention]

[0014] Next, embodiments for carrying out the present invention will be specifically described with reference to the drawings. Figure 1 is a perspective view showing the external appearance of an imaging device 1 according to an embodiment of the present invention, and Figures 2(a) and 2(b) are a simplified top view and a simplified side view of this configuration, respectively. Here, the x, y, and z directions (vertical directions) are defined as shown when the field of view direction is in its initial state.

[0015] As shown in Figure 1, in this imaging device 1, an imaging unit 30 to which a camera module 10 consisting of an image sensor and an optical system is fixed is mounted on the side of the main body 40. The main body 40 is mounted on a tripod head 50 on its underside. The tripod head 50 is fixed to a ground facility or the like. As shown in Figure 2, the tripod head 50 and the main body 40 are connected by a rotation axis (horizontal rotation axis) A1 along the vertical direction (z direction), and the main body 40 is rotationally driven relative to the tripod head 50 by rotation axis A1 as indicated by the arrow DP in Figure 1. The main body 40 and the imaging unit 30 are connected by a rotation axis (vertical rotation axis) A2 along the horizontal direction (in the xy plane), and the imaging unit 30 is rotationally driven relative to the main body 40 by rotation axis A2 as indicated by the arrow DT in Figure 1.

[0016] In Figure 2(a), the configuration when the rotation axis A1 of the imaging device 1 is set to its initial value is shown by a solid line, and the configuration when the rotation axis A1 is rotated 30° counterclockwise from this value is shown by a dotted line, both in a simplified manner. As shown here, the angle (pan angle) in the horizontal plane (xy plane in the initial state) in the direction the imaging unit 30 (camera module 10) faces (field of view direction) is controlled by rotating the main body 40 on the rotation axis A1 relative to the pan / tilt head 50.

[0017] Furthermore, in Figure 2(b), the configuration is simplified, with a solid line showing the initial setting angle of the rotation axis A2 and a dotted line showing the configuration when the rotation axis A2 is rotated 30° clockwise from this position. As shown here, the angle (tilt angle) of the imaging unit 30 (camera module 10) in the vertical plane in the field of view direction (yz plane in the initial state) is controlled by rotating the imaging unit 30 on the rotation axis A2 relative to the main body 40.

[0018] The rotation of the rotation shafts A1 and A2 is performed by driving a pan shaft motor and a tilt shaft motor provided on the main body 40. Here, for example, the rotation shaft of the pan shaft motor is provided to be parallel to the rotation shaft A1, and the rotation shaft of the tilt shaft motor is provided to be parallel to the rotation shaft A2, respectively. The driving of the rotation shafts A1 and A2 is performed using pulleys, belts wound around the pulleys, gears, or the like.

[0019] By controlling the pan angle and tilt angle in this manner, various directions in space can be set as the viewing direction of the camera module 10. The basic configuration described above is the same as that described in, for example, Japanese Patent Application Laid-Open No. 2018-055096. Here, as will be described later, the pan shaft motor and the tilt shaft motor are each individual stepping motors. Since a stepping motor rotates by a constant angle each time a pulse is applied, the rotation angles of the rotation shafts A1 and A2 can be controlled by applying a pulse signal, thereby enabling control of the pan angle and the tilt angle.

[0020] Here, as shown in Fig. 2(a), wind pressure sensors 61A and 61B are provided on both sides in the longitudinal direction of the main body 40 in a horizontal plane, and as shown in Fig. 2(b), wind pressure sensors 62A and 62B are respectively fixed on both sides in the longitudinal direction of the imaging unit 30 in a vertical plane. It is assumed that the distances from the wind pressure sensors 61A and 61B to the center of the rotation shaft A1 in Fig. 2(a) are both R1, and the distances from the wind pressure sensors 62A and 62B to the center of the rotation shaft A2 in Fig. 2(b) are both R2. That is, in Figs. 2(a) and 2(b), the two wind pressure sensors are arranged symmetrically with respect to the center of the rotation shaft. Both the wind pressure sensors 61A and 61B detect wind pressure along the x direction when the pan angle is in the initial state (the case indicated by the solid line in Fig. 2(a)), and both the wind pressure sensors 62A and 62B detect wind pressure along the z direction when the tilt angle is in the initial state (the case indicated by the solid line in Fig. 2(b)).

[0021] Figures 3(a) and 3(b) schematically show the situation when wind is irradiated onto the imaging device 1 in the initial state (solid line state) shown in Figures 2(a) and 2(b), causing a change in its orientation. In Figure 3(a), the wind pressure sensor 61A on the upper side of the figure detects wind pressure (force exerted by the wind) P1A, and the wind pressure sensor 61B on the lower side of the figure detects wind pressure P1B. The length of each wind pressure vector shown here corresponds to the absolute value of the wind pressure, and the arrows indicate the wind direction.

[0022] In this case, if the absolute value of wind pressure P1B is greater than the absolute value of wind pressure P1A, the counterclockwise torque T1 around the rotation axis A1 will be the product of the difference between the absolute values ​​of wind pressure P1B and wind pressure P1A and R1. This torque T1 causes the main body 40 to rotate, as shown by the dotted line in Figure 2(a), and the pan angle may change. On the other hand, even if the absolute values ​​of wind pressure P1A and wind pressure P1B are large, if their absolute values ​​are equal, no torque will be generated around the rotation axis A1. Therefore, wind pressure sensors 61A and 61B can be used to recognize the torque applied around the rotation axis A1 in the horizontal plane by the wind.

[0023] In the initial state (solid line) shown in Figure 2(a), the torque applied around the rotation axis A1 is mainly contributed by the x-direction component of the wind pressure, with the contribution of the y-direction component (the longitudinal direction of the main body 40) being small. Since the objective here is to calculate the torque applied around the rotation axis A1, the wind pressure sensors 61A and 61B only need to detect the component of the wind pressure in the direction perpendicular to the longitudinal direction of the main body 40 in Figure 2(a) (the x-direction in the initial state).

[0024] Similarly, as shown in Figure 3(b), the torque applied around the rotation axis A2 in the vertical plane can be calculated using the wind pressure P2A detected by the wind pressure sensor 62A on the left side of the figure and the wind pressure P2B detected by the wind pressure sensor 62B on the right side of the figure. In Figure 3(b), since the absolute value of wind pressure P2B is greater than the absolute value of wind pressure P2A, a clockwise torque T2 around the rotation axis A2 is generated as shown in the figure, corresponding to the product of the difference between these values ​​and R2. This torque T2 causes the imaging unit 30 to rotate, as shown by the dotted line in Figure 2(b), and the tilt angle can change. The magnitude of this torque T2 can be recognized using the wind pressure sensors 62A and 62B, as in the case of torque T1 described above.

[0025] In Figure 3(a), since both wind pressures P1A and P1B are directed to the right in the figure, the torque T1 is assumed to be generated by the difference between them. However, there are cases where the directions of wind pressures P1A and P1B are reversed. Figures 3(c) and (d) schematically show the case where the directions of each wind pressure are as in Figure 3(a). In Figure 3(c), a counterclockwise torque T1 is generated corresponding to the product of the sum of the absolute values ​​of wind pressures P1A and P1B and R1, and in Figure 3(d), a clockwise torque T1 is similarly generated.

[0026] Therefore, it is preferable that the wind pressure sensors 61A and 61B can measure whether the wind direction in Figure 2(a) is to the right or to the left in the figure, and the absolute value of the wind pressure (force received by the wind) along the left-right direction in the figure (the longitudinal direction of the main body 40). Alternatively, separate wind pressure sensors may be provided for measuring wind pressure to the right and wind pressure to the left in the figure. The same applies to the wind pressure sensors 62A and 62B in Figure 2(b). From the wind pressure recognized by this configuration, the torques T1 and T2 can be recognized.

[0027] In a pulse motor, as described above, when changing the pan angle and tilt angle, the rotation angle of the rotating shaft is controlled by switching the current flowing through the stator coil in accordance with the input pulse signal. On the other hand, when maintaining a constant pan angle and tilt angle, this pulse signal is not input. However, in this case, by maintaining the current flowing through the stator coil (static holding current), even if an external torque is applied to the rotating shaft, this torque can be resisted and the rotating shaft can remain stationary. If no static holding current is supplied, the rotating shaft may rotate if an external torque is applied to it.

[0028] Therefore, in order to maintain constant pan and tilt angles against the torques T1 and T2 generated by the wind as described above, it is preferable to continuously supply this static holding current. However, this results in power consumption even when the stepping motor is not being driven, and such power consumption is undesirable, especially when a battery (storage battery) with a limited usable time is used as the power source for the imaging device 1.

[0029] In this imaging device 1, as shown in Figure 3, the static holding current is controlled according to the torques T1 and T2 recognized by the recognized wind pressure, and in particular, when the absolute values ​​of torques T1 and T2 are small, the static holding current is also reduced. This makes it possible to reduce the power consumption of this imaging device 1.

[0030] Figure 4 is a block diagram showing the configuration of the imaging device 1. Here, the video signal obtained by the camera module 10 is output to the outside of the imaging device 1 via the interface unit 51 provided on the pan / tilt head 50 side. The output image signal can then be displayed on a monitor in an external device (not shown), for example, a personal computer.

[0031] Furthermore, the external device generates a field of view control signal to control the field of view direction of the imaging device 1, based on user operation. In reality, there are two types of field of view control signals: one for pan angle control and one for tilt angle control, but here they are described as a single field of view control signal. The camera module 10 is also provided with a zoom mechanism to control the size of the field of view, and this control can also be performed from the external device side, similar to the control of the pan angle and tilt angle. However, since the zoom operation is unrelated to the present invention, the components related to it are omitted from this description.

[0032] In the imaging device 1, the field of view control signal is input via the interface unit 51, and a drive control unit 41 is provided in the main unit 40 that controls the pan angle and tilt angle based on this field of view control signal. In response to the field of view control signal for pan angle control, the drive control unit 41 generates a pulse signal to control the rotation of the pan axis motor (motor) 43 via the pan axis driver 42, thereby controlling the pan angle in the main unit 40. Similarly, in response to the field of view control signal for tilt angle control, the drive control unit 41 controls the rotation of the tilt axis motor (motor) 45 via the tilt axis driver 44 using a pulse signal, thereby controlling the tilt angle in the imaging unit 20. Since the control of the pan angle and tilt angle can be performed independently, the field of view of the camera module 10 can be appropriately controlled from the outside. That is, the drive control unit 41 controls the field of view of the camera module 10 based on an external signal. This operation is the same as that known conventionally.

[0033] Furthermore, the static holding current applied when the pan shaft motor 43 and tilt shaft motor 45 are stopped is also generated by the pan shaft driver 42 and tilt shaft driver 44, respectively. The setting of this static holding current is also performed by the drive control unit 41. The drive control unit 41 sets the static holding current for the pan shaft motor 43 based on the wind pressure recognized by the wind pressure sensors 61A and 61B, and sets the static holding current for the tilt shaft motor 45 based on the wind pressure recognized by the wind pressure sensors 62A and 62B. This setting is performed so that the static holding current is increased when the torque due to the recognized wind pressure is large, and decreased (or set to zero) when the torque is small.

[0034] This operation allows the imaging device 1 to set a large static holding current only when necessary depending on the wind conditions, and to reduce the static holding current when fluctuations in the field of view direction are unlikely to occur even without static holding, thereby reducing the power consumption required to maintain a constant field of view direction. In Figure 4, the imaging device 1 is powered by a power supply 70, which is a storage battery. Because power consumption is reduced in this way, the operating time of the imaging device 1 using this power supply 70 can be extended. Furthermore, this operation is performed substantially only by the drive control unit 41, and the imaging device 1 can be realized by essentially adding a wind pressure sensor to a conventional imaging device that does not have such a function. For this reason, the configuration of the imaging device 1 is simple.

[0035] Figure 5 is a flowchart showing the operation of the drive control unit 41 in this case. Here, only the control related to the pan axis driver 42 and pan axis motor 43 for the static holding operation of the pan angle is described, but similar operations are performed independently for the static holding operation of the tilt angle (tilt axis driver 44, tilt axis motor 45).

[0036] The operation shown in Figure 5 is performed, for example, at a fixed period that is the time unit for this control. Here, first, the drive control unit 41 recognizes whether the operation of the pan shaft motor 43 is currently stopped (i.e., whether the pan shaft driver 42 is not outputting a pulse signal for driving) (S1). If it is not stopped (S1: No), the control related to the stationary holding operation is terminated.

[0037] If the system is stopped (S1: Yes), measurement results from the wind pressure sensors 61A and 61B, which are involved in the control of the pan shaft, are acquired, and the drive control unit 41 recognizes these results (S2). In this case, the direction and absolute value of the wind pressures P1A and P1B in Figure 2(a) are recognized as described above.

[0038] As a result, the drive control unit 41 can recognize the direction of the torque acting on the main body 40 (rotating shaft A1) by the wind from the wind pressures P1A and P1B, as shown in Figures 3(a), (c), and (d) (S3). Similarly, the absolute value of the torque T1 can be recognized from the difference or sum of the absolute values ​​of the wind pressures P1A and P1B (S4).

[0039] The drive control unit 41 sets the static holding current based on the absolute value of the torque T1 (S5). In this case, the static holding current is set appropriately so that it is large when the absolute value of the torque T1 is large, and small when the absolute value of the torque T1 is small.

[0040] Various setting methods are possible in this case. For example, a standard value I1 for the static holding current can be set, and a threshold (first threshold) TT1 can be set for the absolute value of the torque T1. If the absolute value of the torque T1 exceeds TT1, the static holding current is set to I1, and if the absolute value of the torque T1 is less than or equal to TT1, the static holding current is set to zero. This allows for setting the static holding current in two stages. Alternatively, the static holding current can be set more precisely by setting another threshold (second threshold) TT2 (TT2>TT1) for the absolute value of the torque T1. If the absolute value of the torque T1 exceeds TT2, the static holding current is set to I1, and if the absolute value of the torque T1 is less than or equal to TT1, the static holding current is set to zero. The static holding current can be set to change stepwise or continuously between I1 and zero when the absolute value of the torque T1 is between TT1 and TT2.

[0041] Furthermore, the characteristics of the pan shaft motor 43 may differ depending on the direction of rotation. In this case, the static holding current settings (parameters such as I1 and TT1) may be changed according to the recognized torque direction (S3).

[0042] Once the static holding current is set as described above, the drive control unit 41 controls the pan shaft driver 42 to set the static holding current supplied to the pan shaft motor 43 to this value (S6), and the operation ends. As the operation shown in Figure 5 is repeated in short cycles, the static holding current is set each time weather conditions (wind) change moment by moment. In this case, for most of the time the static holding current is set to less than (or zero than) its standard value I1, so the power consumption of this imaging device 1 can be reduced compared to a conventional imaging device in which the static holding current is always set to I1.

[0043] In the above example, as shown in Figure 2, each wind pressure sensor was installed at both ends in the longitudinal direction of the component (main body 40, imaging unit 30) on which it was attached, at positions symmetrical with respect to the rotation axis (positions where the distance to the center of the rotation axis is the same). However, the distance between each wind pressure sensor and the center axis of the rotation axis does not need to be equal. If these distances are not equal, the torques T1 and T2 can be similarly calculated based on the relationship between the force moment due to the wind pressure measured by each wind pressure sensor (product of wind pressure and this distance). This allows for the same control as described above.

[0044] Furthermore, in the above example, wind pressure sensors are installed at both ends in the longitudinal direction of the main body 40 driven by the rotating shaft A1 and the imaging unit 30 driven by the rotating shaft A2, as components driven by the rotating shafts. However, as long as the torque applied to the rotating shafts can be estimated, it is not necessary for each wind pressure sensor to be installed at both ends in the longitudinal direction of each component. Moreover, although the accuracy of operation will decrease, if it is possible to estimate this torque with a single wind pressure sensor depending on the installation location, only one wind pressure sensor may be used corresponding to each rotating shaft. Conversely, three or more wind pressure sensors may be used to recognize the torque. In either case, if the positional relationship between the wind pressure sensor and the rotating shaft is recognized, the torque can be recognized in the same manner as above, and control can be performed accordingly in the same manner as above.

[0045] Furthermore, considering the possibility of sudden external forces being applied, it is preferable to maintain a static holding current above a certain level in the motor at all times. For this reason, the control to reduce the static holding current as described above does not need to be performed at all times, and may only be performed when it is particularly required to reduce power consumption, for example, when the battery level of the power supply 70 becomes low.

[0046] The present invention has been described above based on embodiments. These embodiments are illustrative, and it will be understood by those skilled in the art that various modifications are possible in the combination of these components, and that such modifications also fall within the scope of the present invention. [Explanation of Symbols]

[0047] 1. Imaging device 10 Camera Modules 30 Imaging Unit 40 Main body 41 Drive control unit 42 Pan shaft driver 43. Pan shaft motor (motor) 44 Tilt axis driver 45 Tilt axis motor (motor) 50 Head 51 Interface section 61A, 61B, 62A, 62B Wind pressure sensor 70 Power supply A1 Rotation axis (horizontal rotation axis) A2 Rotation axis (vertical rotation axis)

Claims

1. An imaging device in which the direction of the field of view of the imaging unit is adjusted by the rotation of a rotation axis with respect to the mount on which the imaging unit is attached, A motor that drives the rotating shaft and, when the rotating shaft is not being driven, maintains a stationary holding current to resist external forces and keep the rotating shaft stopped. A component driven by the aforementioned rotating shaft includes a wind pressure sensor installed at a location spaced apart from the rotating shaft in a plan view perpendicular to the rotating shaft, which detects wind pressure at that location, A drive control unit calculates the torque applied around the rotating shaft from the wind pressure recognized by the wind pressure sensor, sets the static holding current to be larger when the absolute value of the torque is large, and sets the static holding current to be smaller when the absolute value of the torque is small, thereby controlling the motor when the rotating shaft is not being driven. An imaging device characterized by comprising the following:

2. The imaging device according to claim 1, further comprising two wind pressure sensors provided at locations separated from each other in the longitudinal direction of the aforementioned component.

3. The imaging device according to claim 2, characterized in that the two wind pressure sensors are installed in symmetrical positions with respect to the rotation axis in the plan view.

4. The imaging device according to claim 1 or 2, characterized in that a storage battery is used as a power source.

5. A drive control method for an imaging device in which the direction of the field of view of the imaging unit that performs imaging is adjusted by the rotation of a rotation axis with respect to a tripod head on which the imaging unit is mounted, A motor that drives the rotating shaft and, when the rotating shaft is not being driven, maintains a stationary holding current to resist external forces and keep the rotating shaft stopped. A component driven by the aforementioned rotating shaft includes a wind pressure sensor installed at a location spaced apart from the rotating shaft in a plan view perpendicular to the rotating shaft, which detects wind pressure at that location, Using, A drive control method for an imaging device, characterized by calculating the torque applied around the rotating shaft from the wind pressure recognized by the wind pressure sensor, setting the static holding current to a large value when the absolute value of the torque is large, and setting the static holding current to a small value when the absolute value of the torque is small, thereby controlling the motor while the rotating shaft is not being driven.

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