WO2016019768A1

WO2016019768A1 - Sound source orientation control apparatus and method for video surveillance

Info

Publication number: WO2016019768A1
Application number: PCT/CN2015/082570
Authority: WO
Inventors: 毛慧; 陈扬坤; 俞海
Original assignee: 杭州海康威视数字技术股份有限公司
Priority date: 2014-08-04
Filing date: 2015-06-26
Publication date: 2016-02-11
Also published as: CN105338292A; CN105338292B

Abstract

Disclosed are a sound source orientation control apparatus and method for video surveillance. In the present invention, a sound pickup component is capable of rotating synchronously with a camera, and thus a dynamic sound source coordinate system rotating synchronously with the camera can be formed. Accordingly, an azimuth angle obtained by resolving on the basis of the dynamic sound source coordinate system is a relative azimuth angle of a sound source with respect to a lens normal of the camera. Further, closed-loop control on the relative azimuth angle can be realized by converging the relative azimuth angle into a preset angle range, and the direction of the sound source is tracked by a lens viewing angle range of the camera through closed-loop control on the relative azimuth angle. Because loop gain generated in closed-loop control on the relative azimuth angle can suppress precision errors generated in an azimuth angle resolving algorithm, the present invention can improve the accuracy of orientation without improving the precision of the resolving algorithm, so that resources consumed for running the algorithm can be saved.

Description

Sound source orientation control device and method for video monitoring

Technical field

The invention relates to video monitoring technology, in particular to a sound source orientation control device and method for video monitoring.

Background technique

In video surveillance, it is usually necessary to track a specific target, but since the location of a specific target in the monitoring scene is often dynamically changed, and the lens viewing angle range of a single camera is difficult to cover all the video surveillance scenarios, in order to achieve specific Tracking of the target, the prior art provides a full coverage mode of the scene, that is, multiple cameras are deployed in the video surveillance scene to overlay all areas of the video surveillance scene with the perspective range of multiple cameras.

However, the full coverage of the scene obviously causes the cost to increase linearly with the number of cameras. Therefore, the prior art also provides a sound source orientation manner, that is, a static sound is formed by using a position and angle fixed sound pickup device. The source coordinate system, when the sound pickup device senses the sound source signal generated by the specific target in the video surveillance scene, the absolute solution of the sound source (that is, the specific target) in the static sound source coordinate system is obtained by solving the sound source signal. The azimuth angle is then used to adjust the camera rotation using the absolute azimuth calculated by the solution so that the camera's viewing angle range tracks the partial area of the sound source (ie, the specific target) in the video surveillance scene.

As can be seen from the above, the sound source orientation mode does not need to overlap the entire area of the video surveillance scene by using the viewing angle range of the plurality of cameras, thereby reducing the number of cameras deployed in the video surveillance scene, thereby saving costs. At the same time, in order to solve the absolute azimuth more accurately to achieve accurate orientation of a specific target, it is necessary to improve the accuracy of the solution algorithm, but as the accuracy of the algorithm continues to increase, the resources consumed by the algorithm are run. It will also increase.

Summary of the invention

In view of this, the present invention provides a sound source orientation control apparatus and method for video surveillance.

The invention provides a sound source orientation control device for video surveillance, comprising: a sound pickup component that can rotate synchronously with a camera; a sound collection component that collects a sound source signal received by the sound pickup component; and an orientation solving component The sound source signal is used to solve the azimuth of the sound source compared to the camera normal of the camera; the angle convergence component is generated when the calculated azimuth angle is outside the preset angle range Azimuth A drive signal that converges to a predetermined range of angles; an adjustment drive component that drives the camera to rotate in synchronization with the sound pickup component in accordance with the drive signal.

The invention provides a sound source orientation control method for video surveillance, comprising: setting a sound pickup component to be synchronously rotatable with a camera; acquiring a sound source signal received by the sound pickup component; and using the sound source signal to calculate the sound The azimuth of the source normal to the camera; when the solved azimuth exceeds a predetermined angular range, a drive signal is generated for converging the azimuth to a predetermined angular range Driving the camera in synchronization with the sound pickup unit according to the drive signal.

The invention also provides a sound source orientation camera for video surveillance, comprising: at least two microphones, rotating synchronously with the camera lens, for collecting sound analog signals generated by at least one sound source in the monitoring area; at least one modulus The conversion chip is connected to the microphone through a wired communication, receives the sound analog signal collected by the microphone and is converted into a sound digital signal; at least one processor is built in the camera and connected to the analog to digital conversion chip through a wired communication for receiving the sound digital signal. Calculating the azimuth of the sound source compared to the camera lens normal; wherein, when the azimuth angle is greater than a preset angle range, a unique corresponding driving signal is generated according to the azimuth angle, and sent to the pan/tilt; the pan/tilt, and the camera lens Connected to receive the drive signal and rotate the camera lens to change the camera lens normal direction.

As can be seen from the above, in the present invention, the sound pickup unit can rotate synchronously with the camera, thereby forming a dynamic sound source coordinate system that rotates synchronously with the camera. Accordingly, based on the dynamic sound source coordinate system, the calculated azimuth angle is The relative azimuth of the sound source compared to the camera's normal to the lens, and further, by converge the relative azimuth within a predetermined range of angles, closed loop control of the relative azimuth can be achieved and The closed-loop control of the azimuth allows the camera's lens angle of view to track the position of the sound source. Since the loop gain generated by the closed-loop control of the relative azimuth can suppress the accuracy error generated by the solution algorithm, the present invention can improve the accuracy of the sound source orientation without increasing the accuracy of the solution algorithm, thereby saving operation. The resources consumed by the algorithm.

In order to achieve the above and related ends, one or more aspects of the present invention include the features which are described in detail below and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail However, these aspects are indicative of only some of the various ways in which the principles of the invention may be employed. Furthermore, the invention is intended to cover all such aspects and their equivalents.

DRAWINGS

Other objects and results of the present invention will become more apparent and appreciated from the <RTIgt; In the drawing:

1 is a schematic structural diagram of a sound source orientation control apparatus for video surveillance according to an embodiment of the present invention;

2a and 2b are schematic views showing a preferred arrangement of the sound pickup member in the exemplary structure shown in FIG. 1;

3a and 3b are schematic diagrams showing examples of closed loop control based on a preferred arrangement as shown in FIG. 2;

FIG. 4 is a schematic flow chart of a sound source orientation control method for video surveillance according to an embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1, the sound source orientation control apparatus for video monitoring in this embodiment includes: a sound pickup unit 11, a sound collection unit 12, an orientation solving unit 13, an angle convergence unit 14, a loop filter unit 15, and an adjustment. Drive component 16.

The sound pickup unit 11 is rotatable in synchronization with the camera 10. Wherein, since the sound pickup unit 11 has the characteristic of rotating in synchronization with the camera 10, the sound source coordinate system formed by the sound pickup unit 11 can be synchronously rotated in accordance with the rotation of the camera 10, and can form a dynamic sound that is synchronously rotated with the camera 10. Source coordinate system.

In practical applications, the sound pickup unit 11 can be fixed to the camera 10 to form a characteristic that the sound pickup unit 11 can rotate synchronously with the camera 10, and the sound pickup unit 11 fixed to the camera 10 can adopt different arrangements to realize two. Orientation of dimensional space, or higher dimensional space.

Wherein, if the sound pickup unit 11 is required to realize the sound source orientation in the range of 180° of the two-dimensional space, referring to FIGS. 2a and 2b, the sound pickup unit 11 may include a pair of

microphones

11a and 11b located in the same plane, which The

microphones

11a and 11b are respectively fixed to the camera 10 on both sides of the normal N of the lens 100 to form a two-dimensional plane coplanar with the normal N of the lens 100. It should be noted that, in FIG. 2a and FIG. 2b, only the spherical camera 100 is taken as an example, but the specific shape of the camera 100 does not affect the arrangement of the sound pickup member 11.

If the sound pickup unit 11 is required to achieve sound source orientation in a range of 360° in a two-dimensional space, the sound pickup unit 11 may include three microphones in the same plane.

If the sound pickup unit 11 is required to realize the orientation of the three-dimensional and three-dimensional space, the sound pickup unit 11 may include at least four non-coplanar microphones, wherein for each of the four microphones, it may be similar to FIG. 2a. And as shown in FIG. 2b, respectively fixed to the camera 10 on both sides of the normal N of the lens 100 to form a two-dimensional plane coplanar with the normal N of the lens 100, but only a two-dimensional plane formed by each of the two microphones The angles are different, that is, they are not parallel to each other.

The sound collecting section 12 collects the sound source signal received by the sound pickup section 11. Wherein, for the case where the sound pickup unit 11 is implemented based on a microphone, the audio signal picked up by the sound pickup unit 11 is usually an analog signal. At this time, the main function of the sound collection unit 12 is to sample the analog signal to obtain a digitized sound. The source signal, for example, the sound collecting component 12 may be a sampling circuit having an analog-to-digital conversion function, and may be an analog-to-digital conversion circuit.

The azimuth solving unit 13 uses the sound source signal to calculate the azimuth of the sound source compared to the lens normal of the camera. The azimuth solving component 13 can perform the solution of the sound source signal by using any existing solution algorithm. Since the sound pickup component 11 forms a dynamic sound source coordinate system that rotates synchronously with the camera, the azimuth angle obtained according to any one of the solution algorithms is based on the dynamic sound source coordinate system as a reference coordinate, so that the camera is used only. The lens normal is the coordinate axis of the dynamic sound source coordinate system, and the azimuth calculated by the azimuth solving component 13 is the azimuth of the sound source compared to the camera normal of the camera. The orientation calculation component 13 can be a processor.

The angle convergence member 14 generates a drive signal for converging the azimuth angle to within a predetermined angular range when the calculated azimuth angle is outside the predetermined angular range. Wherein, if the solved azimuth angle exceeds the preset angle range in the forward direction, the driving signal generated by the angle convergence component 14 indicates that the adjustment camera and the sound pickup component are rotated in the reverse direction, so that the sound source is The azimuth corner is within a predetermined range of angles. On the contrary, if the azimuth obtained by the solution exceeds the preset angle range in the reverse direction, the driving signal generated by the angle convergence member 14 indicates that the adjustment camera and the sound pickup member are rotated in the forward direction, which also makes The azimuth of the sound source is within a predetermined range of angles. In addition, the angle convergence member 14 may not need to generate a drive signal when the solved azimuth does not exceed a predetermined angular range.

The loop filter component 15 is located between the angle convergence component 14 and the adjustment drive component 16.

The adjustment driving section 16 drives the camera 10 and the sound pickup section 11 to rotate in synchronization in accordance with the driving signal. Wherein, the main function of the adjustment driving component 16 is to rotate the camera 10 and the sound pickup component 11 in the correct direction according to the driving signal, so that the azimuth angle of the sound source can fall within a preset angle range, of course, except In addition to adjusting the direction of rotation, the adjustment drive member 16 can further adjust other parameters such as the speed of rotation according to actual needs; in addition, the adjustment drive member 16 can be realized by any of the components having driving capability, such as a servo device, and the camera 10 can The camera is mounted on the rotating pan/tilt driven by the adjustment driving member 16 so that the camera 10 has a degree of freedom of rotation, so that the camera 10 can be rotated as long as the adjustment driving member 16 drives the rotation of the pan/tilt head, and accordingly, is fixed to the camera 10. The sound pickup unit 11 can be rotated in synchronization with the camera 10. The adjustment drive member 16 can be a drive motor.

As can be seen from the above, in the sound source orientation control apparatus for video surveillance of the present embodiment, the sound pickup unit 11 that can rotate in synchronization with the camera 10 can form a dynamic sound source coordinate system that rotates with the camera, and thus based on the dynamic sound The source coordinate system, the azimuth obtained by the azimuth solving unit 13 is the relative azimuth of the sound source compared to the normal N of the lens 100 of the camera 10, and thus, by the cooperation of the angle convergence member 14 and the adjustment driving member 16, The relative azimuth can be converge to a predetermined range of angles to achieve closed-loop control of the relative azimuth, and the closed-loop control of the relative azimuth causes the lens 100 to view the sound source range of the lens 100. Position.

According to the control theory, the closed-loop control of the relative azimuth can inevitably generate the loop gain K to suppress the accuracy error generated by the solving algorithm in the conventional open-loop mode, that is, the open-loop precision error E. Wherein, the closed-loop precision error X obtained by the open-loop precision error E and the loop gain K is satisfied to satisfy X=E/(1+K), and considering K>>1 in the normal case, X=E/ (1+K) is simplified as X≈E/K. It can be seen that the closed-loop precision error X obtained after the loop gain K is suppressed is obviously smaller than the open-loop precision error E generated by the solution algorithm. Therefore, by the closed-loop control of the above relative azimuth, the accuracy of the sound source orientation can be improved without increasing the accuracy of the solution algorithm, thereby saving resources consumed by the running algorithm. In addition, the loop gain K can be adjusted by the loop filter unit 15, and theoretically, the loop gain K infinity can be achieved, and the closed loop precision error X≈E/K obtained by suppressing the loop gain K approaches zero.

Moreover, the convergence target of the above closed-loop control is an angular range instead of a single angle value, because the lens angle of view of the camera has a certain angular range as long as the sound source (ie, the specific target monitored) is in the angular range of the lens 100 perspective. Therefore, the azimuth angle of the sound source compared to the normal line N of the lens 100 of the camera 10 does not have to be adjusted, so that the requirement for the closed loop precision error X≈E/K can be reduced, and preferably, the closed loop precision error X≈E /K remains within the pre-set angle range.

Referring to FIGS. 3a and 3b (the dynamic sound source coordinate system is exemplarily shown in the XY coordinate system in FIGS. 3a and 3b), based on the arrangement of the sound pickup unit 11 as shown in FIG. 2, a predetermined angle is assumed. The range is [-5°, 5°], and the loop error X≈E/K is in the range of [-5°, 5°] by adjusting the loop gain K. First, as shown in Figure 3a, the sound is as shown in Figure 3a. The source S moves to a position of -45° of the normal 100 of the lens 100 of the camera 10 (coincident with the Y-axis of the dynamic sound source coordinate system), and then the drive signal generated by the angle convergence member 14 is transmitted to the adjustment through the loop filter unit 15. The driving member 16 is driven by the adjustment driving member 16 to rotate the camera 10 and the pair of

microphones

11a and 11b in the negative direction by rotating the pan/tilt, as shown in FIG. 3b, so that the lens 100 normal N of the camera 10 is tracked to the sound source. S is within the error range of [-5°, 5°].

Generating a driving signal for driving the camera lens to rotate toward the second microphone when the processor determines that the azimuth is close to the second microphone and away from the first microphone; when the processor determines that the azimuth is close to the first microphone and is far away In the second microphone, a drive signal for driving the camera lens to rotate in the direction of the first microphone is generated.

In addition, the convergence target of the closed-loop control with a preset angle range actually makes the closed-loop control have a certain tolerance to the above-mentioned relative azimuth variation amplitude, thereby preventing the rotation of the camera 10 and the sound pickup component 11 from the sound source. Frequent jitter caused by small fluctuations in orientation to improve the stability of sound source orientation. For example, if in the example shown in FIGS. 3a and 3b, if the sound source S moves to a position of ±4° or even a smaller angle of the normal N of the lens 100 of the camera 10, the angle convergence member 14 does not generate a drive. signal. Accordingly, the predetermined range of angles is preferably less than or equal to the range of viewing angles of the lens 100 of the camera 10 to ensure that the closed loop control can always be targeted within an angular range of the source of view of the lens 100.

The above is the sound source orientation control device for video surveillance in this embodiment. Based on the principle similar to the above-described sound source orientation control device, the present embodiment also provides a sound source orientation control method for video surveillance.

Referring to FIG. 4, the sound source orientation control method for video surveillance in this embodiment includes:

Step 400, setting the sound pickup component to be rotatable in synchronization with the camera.

Wherein, since the sound pickup member has the characteristic of being rotatable in synchronization with the camera, the sound source coordinate system formed by the sound pickup member can be synchronously rotated as the camera rotates, and a dynamic sound source coordinate system capable of synchronously rotating with the camera can be formed. In an actual application, step 400 may form a rotation synchronized with the camera by fixing the sound pickup component to the camera, and the sound pickup device fixed to the camera may adopt a different arrangement to realize a two-dimensional space or a higher dimension. For the orientation of the space, the specific arrangement of the sound pickup device can be referred to the description of the sound source orientation control device portion, and details are not described herein again.

Step 401: Acquire a sound source signal received by the sound pickup component, and then perform step 402.

Step 402: Calculate the azimuth of the sound source compared to the lens normal of the camera by using the sound source signal, and then perform step 403.

Step 403, it is determined whether the azimuth obtained by the solution is outside the preset angle range, and if so, step 404 is performed, otherwise returns to step 401;

Step 404, when the calculated azimuth angle is outside the preset angle range, generating a driving signal for converging the azimuth angle to a preset angle range, and then performing step 405.

The step 404 can perform the solution of the sound source signal by using any existing solution algorithm. Since the sound pickup component forms a dynamic sound source coordinate system that rotates synchronously with the camera, the azimuth angle obtained according to any one of the solution algorithms is based on the dynamic sound source coordinate system as a reference coordinate, and thus, as long as the camera The lens normal is the coordinate axis of the dynamic sound source coordinate system, and the azimuth angle calculated in step 404 is the azimuth angle of the sound source compared to the camera normal of the camera.

Step 405: Perform loop filtering on the generated driving signal, and then perform step 406.

Step 406: Driving the camera and the sound pickup unit to rotate synchronously according to the driving signal, and then returning to step 401.

Wherein, the camera can be installed in the rotating pan/tilt driven by step 406 so that the camera has a degree of freedom of rotation, so that in the case where the sound pickup member is fixed to the camera, step 406 is rotated by driving the rotating pan/tilt equipped with the camera. The camera is driven to rotate so that the sound pickup unit fixed to the camera can also rotate in synchronization with the camera.

So far, the flow of the above method. Wherein, in the flow, step 401 - step 406 can be iteratively executed cyclically.

As can be seen from the above, in the sound source orientation control method for video surveillance of the embodiment, the sound pickup device has the characteristic of being rotatable synchronously with the camera, and can thereby form a dynamic sound source coordinate system that rotates synchronously with the camera, and thus based on the In the dynamic sound source coordinate system, the azimuth obtained by the solution is the relative azimuth of the sound source compared to the camera normal of the camera, and thus, by converge the relative azimuth angle within a predetermined angle range, Closed-loop control of the relative azimuth, and by the closed-loop control of the relative azimuth, the lens viewing angle range of the camera tracks the position of the sound source.

According to the previous description in the sound source directional control device section, the closed-loop precision error X obtained after the loop gain K is suppressed is obviously smaller than the open-loop precision error E generated by the solution algorithm. Therefore, by the closed-loop control of the above relative azimuth, The accuracy of the sound source orientation can be improved without increasing the accuracy of the solution algorithm, thereby saving the resources consumed by running the algorithm. In addition, in the same way as the sound source orientation control device, the loop gain K can be adjusted by the loop filtering performed in step 404 in the above process, and theoretically, the loop gain K infinity can be achieved, and the loop gain K can be suppressed. The resulting closed-loop accuracy error X≈E/K approaches zero.

Moreover, the convergence target of the above closed-loop control is an angular range instead of a single angle value, which can reduce the requirement of the closed-loop precision error X≈E/K, and preferably keeps the closed-loop precision error X≈E/K at a predetermined value. It can be within the angle range. And, the convergence target of the closed-loop control with a preset angle range actually makes the closed-loop control have a certain tolerance to the above-mentioned relative azimuth variation amplitude, thereby avoiding the rotation of the camera and the sound pickup component with the sound source orientation. Frequent jitter caused by small fluctuations to improve the stability of sound source orientation. Accordingly, the predetermined range of angles is preferably less than or equal to the range of lens angles of the camera to ensure that the closed loop control is always targeted within an angular range of the sound source at the perspective of the lens.

The embodiment of the present application further provides a sound source orientation camera for video surveillance, comprising: at least two microphones, rotating synchronously with the camera lens, and used for sound analog signals generated by at least one sound source; at least one analog to digital conversion The circuit establishes a connection relationship with the microphone, receives the sound analog signal collected by the microphone, and converts The sound digital signal; at least one processor, built in the camera, and the analog-to-digital conversion circuit establishes a connection relationship for receiving the sound digital signal, and calculating the azimuth of the sound source compared to the camera lens normal, wherein The azimuth angle is greater than a preset angle range, and the driving signal is generated according to the azimuth angle and sent to the driving motor; the driving motor is connected to the processor for receiving the driving signal, and controlling the movement of the gimbal according to the driving signal; the pan/tilt, and the camera The lens connection is used to drive the camera lens to rotate according to the driving of the driving motor.

Optionally, the microphone is mounted on the camera lens, and the number of the microphones is two, three or four.

Optionally, the drive signal includes a speed parameter of the pan-tilt rotation and an adjustment parameter of the azimuth.

Optionally, when the azimuth angle is greater than the preset angle range, generating the driving signal according to the azimuth angle includes: when the processor determines that the azimuth is close to the second microphone and is away from the first microphone, generating a driving lens for driving The direction of the second microphone changes the driving signal in the normal direction of the lens; when the processor determines that the azimuth is close to the first microphone and away from the second microphone, generating a lens for driving the camera lens to change the lens normal toward the direction of the first microphone Directional drive signal.

Optionally, calculating the azimuth of the sound source compared to the camera lens normal includes: the microphone and the camera lens form a dynamic sound source coordinate system, and the processor uses the sound source orientation algorithm to calculate the sound source compared to the camera lens normal Azimuth.

Optionally, after the processor generates a corresponding driving signal according to the azimuth angle, the method includes: the processor filters the driving signal by using the loop filter, and if the azimuth angle is within a preset angular range, the driving signal is not generated. If the azimuth angle is greater than a predetermined range of angles, a unique corresponding drive signal is generated.

The various functional units provided by the embodiments of the present application may be operated in a mobile terminal, a computer terminal, or the like, or may be stored as part of a storage medium.

Thus, embodiments of the present invention may provide a camera that may be any one of the camera groups. Optionally, in this embodiment, the camera may also be replaced with a device having an imaging or recording function.

In this embodiment, the camera may execute the program code of the following steps in the sound source orientation control method for video monitoring: collecting a sound source signal received by the sound pickup component, wherein the sound pickup component rotates synchronously with the camera; Calculating, by using the sound source signal, an azimuth of the sound source compared to a lens normal of the camera; when the azimuth angle exceeds a preset angle range, generating is configured to converge the azimuth angle to the preset angle a driving signal within the range; driving the camera to rotate synchronously with the sound pickup unit according to the driving signal.

Optionally, the camera may comprise: one or more processors, memory, and transmission means.

The memory can be used to store software programs and modules, such as the sound source orientation control method for video surveillance and the program instructions/modules corresponding to the device in the embodiment of the present invention, and the processor runs the software program and the module stored in the memory. Thus, various functional applications and data processing are performed, that is, the above-described sound source orientation control method for video monitoring is implemented. The memory may include a high speed random access memory, and may also include non-volatile memory such as one or more magnetic storage devices, flash memory, or other non-volatile solid state memory. In some examples, the memory can further include memory remotely located relative to the processor, which can be connected to the terminal over a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The above transmission device is for receiving or transmitting data via a network. Specific examples of the above network may include a wired network and a wireless network. In one example, the transmission device includes a Network Interface Controller (NIC) that can be connected to other network devices and routers via a network cable to communicate with the Internet or a local area network. In one example, the transmission device is a Radio Frequency (RF) module for communicating with the Internet wirelessly.

Specifically, the memory is used to store preset action conditions and information of the preset rights user, and an application.

The processor can call the memory stored information and the application by the transmitting device to execute the program code of the method steps of each of the alternative or preferred embodiments of the above method embodiments.

Embodiments of the present invention also provide a storage medium. Optionally, in this embodiment, the foregoing storage medium may be used to save program code executed by the sound source orientation control method for video surveillance provided by the foregoing method embodiment and the device embodiment.

Optionally, in this embodiment, the foregoing storage medium may be located in any one of the camera groups.

Optionally, in the embodiment, the storage medium disposed in the camera is configured to store program code for performing the following steps: acquiring a sound source signal received by the sound pickup unit, wherein the sound pickup unit and the camera Synchronous rotation; using the sound source signal to calculate an azimuth angle of the sound source compared to the camera normal of the camera; when the azimuth angle exceeds the preset angle range, generating is used to converge the azimuth angle to the a driving signal within a preset angle range; driving the camera to rotate synchronously with the sound pickup unit according to the driving signal.

Alternatively, in the present embodiment, the storage medium may also be provided as program code for storing various preferred or optional method steps provided by the sound source orientation control method for video monitoring.

The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalents, improvements, etc., which are made within the spirit and principles of the present invention, should be included in the present invention. Within the scope of protection.

Claims

A sound source orientation control device for video surveillance, comprising:

a sound pickup unit that can rotate in synchronization with the camera;

a sound collecting component that collects a sound source signal received by the sound pickup component;

a position solving component, which uses the sound source signal to calculate an azimuth angle of the sound source compared to the camera normal of the camera;

An angle convergence component that generates a driving signal for converging the azimuth angle to a predetermined angular range when the calculated azimuth angle is outside a predetermined angular range, and the preset angular range is smaller than Or equal to the lens angle of view of the camera;

The drive unit is adjusted to drive the camera to rotate in synchronization with the sound pickup unit in accordance with the drive signal.
The sound source orientation control device according to claim 1, wherein the sound pickup unit is fixed to the camera to form a rotation synchronized with the camera.
The sound source orientation control device according to claim 2, wherein the sound pickup unit comprises at least two microphones.
The sound source orientation control device according to claim 1, wherein the camera is mounted on the pan/tilt head, and the pan/tilt head is driven by the adjustment driving member.
The sound source orientation control device according to claim 1, further comprising:

A loop filtering component is located between the angular convergence component and the adjustment drive component.
A sound source orientation control method for video surveillance, comprising:

Setting the sound pickup unit to rotate in synchronization with the camera;

Acquiring the sound source signal received by the sound pickup unit;

Using the sound source signal to solve the azimuth of the sound source compared to the camera's lens normal;

When the calculated azimuth angle is outside the preset angle range, a driving signal for converging the azimuth angle to a preset angle range is generated, and the preset angle range is less than or equal to the lens of the camera. Range of viewing angles;

The camera is driven to rotate in synchronization with the sound pickup unit according to the driving signal.
The sound source orientation control method according to claim 6, wherein the sound pickup unit is rotated in synchronization with the camera by fixing the sound pickup unit to the camera.
The sound source orientation control method according to claim 7, wherein the sound pickup unit comprises at least two microphones.
The sound source orientation control method according to claim 6, wherein driving the camera to rotate synchronously with the sound pickup unit according to the driving signal comprises:

The camera and the sound pickup unit are driven to rotate synchronously by driving the rotation of the rotating pan/tilt equipped with the camera.
The sound source orientation control method according to claim 6, wherein before the driving of the camera and the sound pickup unit in synchronization with the driving signal, the method further comprises:

The drive signal is loop filtered.
A sound source oriented camera for video surveillance, comprising:

At least 2 microphones, rotating synchronously with the camera lens, for collecting sound analog signals generated by at least one sound source;

At least one analog-to-digital conversion circuit establishes a connection relationship with the microphone, and receives a sound analog signal collected by the microphone and converts into a sound digital signal;

At least one processor, built in the camera, and connected to the analog-to-digital conversion circuit for receiving the sound digital signal, and calculating an azimuth of the sound source compared to a camera lens normal, wherein When the azimuth angle is greater than a preset angle range, generating a driving signal according to the azimuth angle, and transmitting the driving signal to the driving motor;

The driving motor is connected to the processor for receiving the driving signal, and controlling the movement of the gimbal according to the driving signal;

The pan/tilt head is connected to the camera lens for driving the camera lens to rotate according to driving of the driving motor.
The video camera according to claim 11, wherein said microphone is mounted on a camera lens, and the number of said microphones is two, three or four.
The camera according to claim 11, wherein said drive signal comprises a speed parameter of said pan-tilt rotation and an adjustment parameter of said azimuth angle.
The camera according to claim 11, wherein when the azimuth angle is greater than a predetermined range of angles, generating a driving signal according to the azimuth angle comprises:

Generating a driving signal for driving the camera lens to rotate toward the second microphone when the processor determines that the azimuth is close to the second microphone and away from the first microphone;

When the processor determines that the azimuth is close to the first microphone and away from the second microphone, generating a driving signal for driving the camera lens to rotate in a direction toward the first microphone.
The camera of claim 11 wherein calculating an azimuth of said sound source relative to a normal to said camera lens comprises:

The microphone and the camera lens form a dynamic sound source coordinate system, and the processor uses a sound source orientation algorithm to calculate an azimuth of the sound source compared to a camera lens normal.
The camera according to claim 11, wherein after the processor generates a corresponding driving signal according to the azimuth angle, the method includes:

The processor performs a filtering process on the driving signal by using a loop filter, and if the azimuth angle is within a preset angular range, the driving signal is not generated, if the azimuth angle is greater than the preset The angular range then generates a unique corresponding drive signal.