Communication system and method for controlling communication system

A communication system according to the present disclosure includes a camera configured to be able to photograph a user who is a communication partner and a microphone configured to be able to form a beam-forming in a specific direction. The control unit identifies a position of the mouth of a user using an image of the user taken by the camera and controls a position of a head part so that the identified position of the mouth of the user is included in a region of the beam-forming.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese patent application No. 2019-049961, filed on Mar. 18, 2019, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

The present disclosure relates to a communication system and a method for controlling a communication system.

In recent years, communication systems that communicate with users have been developed. Japanese Unexamined Patent Application Publication No. 2008-126329 discloses a technique related to a voice recognition robot that performs an action by recognizing a voice of a user.

SUMMARY

The voice recognition robot disclosed in Japanese Unexamined Patent Application Publication No. 2008-126329 includes a holding unit that holds a microphone. Then, the position of the mouth of a user is identified using an image of the user taken by a camera, and the posture of the holding unit is controlled so that the microphone held by the voice recognition robot approaches the mouth of the user.

However, the speech recognition robot disclosed in Japanese Unexamined Patent Application Publication No. 2008-126329 has a problem that as it is configured so that the microphone is held by the holding unit, the apparatus configuration becomes complicated. Further, in the communication system, as it is necessary to appropriately communicate with a user, it is necessary to accurately recognize a voice of the user. Accordingly, there is a need for a communication system that has a simple apparatus configuration and that can accurately recognize a voice of a user.

In view of the aforementioned problem, an object of the present disclosure is to provide a communication system that has a simple apparatus configuration and that can accurately recognize a voice of a user, and a method for controlling a communication system.

A first exemplary aspect is a communication system, including: a main body part; a head part attached to the main body part so that the head part can be displaced with respect to the main body part; a control unit configured to be able to control a position of the head part with respect to the main body part; a camera provided in the head part and configured to be able to photograph a user who is a communication partner; and a microphone provided in the head part and configured to be able to form a beam-forming in a specific direction. The control unit identifies a position of a mouth of the user using an image of the user taken by the camera and controls the position of the head part so that the identified position of the mouth of the user is included in a region of the beam-forming.

In the above-described communication system, the camera configured to be able to photograph a user and the microphone configured to be able to form a beam-forming in a specific direction are provided in the head part. Thus, it is possible to omit a holding unit that holds the microphone, and accordingly to make the apparatus configuration of the communication system simple. Further, the position of the mouth of the user is identified using the image of the user who is a communication partner, and the position of the head part is controlled so that the identified position of the mouth of the user is included in a region of the beam-forming. Accordingly, it is possible to accurately recognize a voice of the user.

In the above-described communication system, the control unit may be further configured to be able to control a direction of a line of sight of an eye part provided in the head part. Further, the control unit may control the direction of the line of sight so as to face in a direction of a face of the user when the control unit controls the position of the head part.

By controlling a direction of the line of sight of the communication system so as to face in a direction of the face of a user as described above, it is possible to prevent the line of sight of the communication system from deviating from the user. Accordingly, it is possible to give an impression to the user that the communication system is carefully listening to him/her.

In the above-described communication system, the control unit may identify a position of the face of the user using the image of the user taken by the camera and control the direction of the line of sight so as to face in the direction of the face of the user.

In the above-described communication system, the control unit may control the direction of the line of sight based on an amount of movement of the head part when the control unit controls the position of the head part.

In the above-described communication system, the control unit may calculate coordinates of the position of the mouth of the user using the image of the user taken by the camera, and calculate the amount of movement of the head part using the calculated coordinates of the position of the mouth and a relative positional relation between the microphone and the camera.

Another exemplary aspect is a method for controlling a communication system, the communication system including: a main body part; a head part attached to the main body part so that the head part can be displaced with respect to the main body part; a camera provided in the head part and configured to be able to photograph a user who is a communication partner; and a microphone provided in the head part and configured to be able to form a beam-forming in a specific direction, the method including: photographing a user who is a communication partner; identifying a position of a mouth of the user using the photographed image of the user; and controlling a position of the head part so that the identified position of the mouth of the user is included in a region of the beam-forming.

In the above-described method for controlling a communication system, the position of the mouth of the user is identified using the image of the user who is a communication partner, and the position of the head part is controlled so that the identified position of the mouth of the user is included in a region of the beam-forming of the microphone. Accordingly, it is possible to accurately recognize a voice of the user.

The above-described method for controlling a communication system may further include controlling a direction of the line of sight so as to face in a direction of a face of the user when the control unit controls the position of the head part.

By controlling a direction of the line of sight of the communication system so as to face in a direction of a face of a user as described above, it is possible to prevent the line of sight of the communication system from deviating from the user. Accordingly, it is possible to give an impression to the user that the communication system is carefully listening to him/her.

According to the present disclosure, it is possible to provide a communication system that has a simple apparatus configuration and that can accurately recognize a voice of a user, and a method for controlling the communication system.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present disclosure is described hereinafter with reference to the drawings.

FIGS. 1 and 2are a front view and a side view, respectively, each of which shows an example of an appearance configuration of a communication system according to this embodiment. As shown inFIGS. 1 and 2, a communication system1according to this embodiment includes a head part100and a main body part110. The head part100is attached to the main body part110so that the head part can be displaced with respect to the main body part110. In the head part100, ear parts31aand31b, eye parts32aand32b, and a nose part33are provided. In the main body part110, a body part36, arm parts37aand37b, and leg parts38aand38bare provided. Although each ofFIGS. 1 and 2shows an apparatus (robot) having an appearance that imitates an animal as an example, the appearance configuration of the communication system according to this embodiment is not limited to this and can be freely determined.

Microphones12aand12bare provided in the ear parts31aand31b, respectively. By using the microphones12aand12b, it is possible to pick up sounds around the communication system1(in particular, a voice of a user). In this embodiment, each of the microphones12aand12bis configured so that it can form a beam-forming in a specific direction. For example, as shown inFIG. 2, the microphone12ais configured so that it can form a substantially conical beam-forming45having a predetermined angle around a specific direction41.

The microphones12aand12bmay each independently form a beam-forming, or one beam-forming may be formed using both of the microphones12aand12b.

For example, when the microphones12aand12beach independently form a beam-forming, a plurality of microphones (e.g., nondirectional microphones) are provided in each of the microphones12aand12b. Then, by performing beamforming processing on each of the voice signals picked up by the plurality of microphones, it is possible to form the beam-forming45having directivity in the specific direction41independently in each of the microphones12aand12b.

Further, for example, when one beam-forming is formed using both of the microphones12aand12b, it is possible to form the beam-forming45having directivity in the specific direction41by performing beamforming processing using both the voice signals picked up by the microphone12aand the voice signals picked up by the microphone12b.

For example, the beamforming processing can be performed by a control unit10. Further, the beamforming processing may be performed by a CPU incorporated in a microphone array of the microphone12. Further, in this embodiment, a directional microphone may be used for each of the microphones12aand12b. Note that the microphones12aand12bmay be provided only in one of the ear parts31aand31b, and may be provided in a part (e.g., a forehead) of the head part100other than the ear parts31aand31b. In the following, when the microphones12aand12bare referred to without being distinguished from each other, they are simply referred to as a microphone12. The same applies to the other components (an eye part32and the like).

A camera11is provided in the nose part33. The camera11photographs a space in front of the communication system1(in particular, a user who is a communication partner). Further, the nose part33projects forward from the head part100to imitate a nose of an animal. By providing the camera11at a position projected from the head part100as described above, it is possible to gives a wider view of the front of the communication system1from the camera11(i.e., a wide angle photographing can be performed).

In the communication system1according to this embodiment, the microphones12aand12bare fixed to the ear parts31aand31b, and the camera11is fixed to the nose part33. Accordingly, even when the head part100is moved with respect to the main body part110, the relative positional relation between the microphones12aand12band the camera11remains fixed.

Further, as shown inFIG. 1, the eye parts32aand32bare provided in the head part100. Each of the eye parts32aand32bcan be formed using the respective displays14aand14b. That is, a line of sight of the communication system1can be represented by displaying eye images34aand34bon the respective displays14aand14b. A direction of the line of sight of the communication system1can be controlled by changing the eye images34aand34bdisplayed on the displays14aand14b. Note that the image of the eyes may include not only the image of the eyeball but also images of elements related to the eyes such as eyelids, eyebrows, and tears. Further, the displays14aand14bcan be composed of, for example, a liquid crystal panel or an organic EL panel.

Note that the eye parts32aand32bmay be formed using, for example, models that imitate eyes and a servo motor that drives the models of the eyes, in addition to the displays14aand14b. In this case, a direction of the line of sight of the communication system1can be changed by displacing the models of the eyes using the servo motor.

Next, the system configuration of the communication system according to this embodiment is described with reference to a block diagram shown inFIG. 3. As shown inFIG. 3, the communication system1according to this embodiment includes the camera11, the microphone12, a drive unit13, the display14, a speaker15, and the control unit10.

The camera11shown in the block diagram ofFIG. 3corresponds to the camera11provided in the nose part33of the communication system1shown inFIG. 1. The camera11photographs a space in front of the communication system1(specifically, a user who is a communication partner) and provides the photographed image data to the control unit10.

The microphone12shown in the block diagram ofFIG. 3corresponds to the microphones12aand12bprovided in the ear parts31aand31bof the communication system1shown inFIG. 1. The microphone12picks up sounds (in particular, a voice of a user) around the communication system1and provides the picked-up voice signals to the control unit10. For example, the microphone12includes a plurality of microphones (e.g., nondirectional microphones), and the control unit10can form the beam-forming45(seeFIG. 2) having directivity in the specific direction41by performing beamforming processing on the voice signals picked up by the plurality of microphones.

The drive unit13drives the head part100. Specifically, the drive unit13drives the head part100in accordance with a control signal provided from the control unit10. For example, the drive unit13can drive the head part100so that the head part100faces downward or upward and faces left or right. Further, the drive unit13may drive the head part100so that the head part100faces in an oblique direction. For example, the drive unit13can be configured using a servo motor or the like.

The display14shown in the block diagram ofFIG. 3corresponds to the displays14aand14bprovided in the eye parts32aand32bof the communication system1shown inFIG. 1. The display14is configured so as to display the eye images34aand34b(seeFIG. 1) corresponding to the control signal provided from the control unit10. That is, the control unit10controls a direction of the line of sight of the communication system1by controlling the eye images34aand34b(seeFIG. 1) displayed on the respective displays14aand14b.

The speaker15outputs a sound corresponding to the voice signal provided from the control unit10. This configuration enables the communication system1to talk to a user (a communication partner).

The control unit10performs various types of controls of the communication system1. Specifically, the control unit10receives image data from the camera11and receives a voice signal from the microphone12. Further, the control unit10outputs a control signal corresponding to the amount of movement of the head part100to the drive unit13. Further, the control unit10outputs, to the display14, a control signal for displaying an eye image on the display14. Further, the control unit10outputs, to the speaker15, a voice signal for outputting a voice from the speaker15.

Further, in the communication system1according to this embodiment, the control unit10identifies a position of the mouth of a user using an image taken by the camera11, and control a position of the head part100so that the identified position of the mouth of the user is included in a region of the beam-forming of the microphone12.

Specifically, as shown inFIG. 3, the control unit10includes a position identification unit21, a movement amount calculation unit22, and a control signal output unit23. The position identification unit21identifies a position of the mouth of a user using an image of the user taken by the camera11. At this time, the position identification unit21may calculate the coordinates of the position of the mouth of the user using the image of the user taken by the camera11.

The movement amount calculation unit22calculates the amount of movement of the head part100when the position of the head part100is moved so that the position of the mouth of the user is included in the region of the beam-forming of the microphone12. For example, the movement amount calculation unit22may calculate the amount of movement of the head part100using the coordinates of the position of the mouth of the user and the relative positional relation between the microphone12and the camera11. Note that a specific method for calculating the amount of movement of the head part100will be described later.

The control signal output unit23generates a control signal corresponding to the amount of movement of the head part100calculated by the movement amount calculation unit22(i.e., a control signal of the drive unit13) and outputs the generated control signal to the drive unit13.

Further, in the communication system1according to this embodiment, the control unit10may be configured so that it can control a direction of the line of sight of the eye part32provided in the head part100. For example, the control unit10may control the direction of the line of sight so as to face in the direction of the face of a user when the control unit10controls the position of the head part100.

Further, the control unit10may identify the position of the face of a user using the image of the user taken by the camera11and control the direction of the line of sight so as to face in the direction of the face of the user. Furthermore, the control unit10may control the direction of the line of sight based on the amount of movement of the head part100when the control unit10controls the position of the head part100.

Next, an operation of the communication system according to this embodiment is described.FIG. 4is a flowchart for explaining the operation of the communication system according to this embodiment.FIGS. 5 to 7are side views for explaining the operation of the communication system according to this embodiment. In the following description, a case where the communication system1is placed on a table40and a user50and the communication system1face each other is described as an example.

First, the communication system1photographs the user50who is a communication partner (Step S1inFIG. 4). Specifically, as shown inFIG. 5, the communication system1photographs the user50using the camera11provided in the nose part33thereof. Note that at this time, the center direction41of the beam-forming of the microphone12faces a position above the position of a mouth51of the user50.

Next, the communication system1identifies the position of the mouth51of the user50using the image of the user50photographed in Step S1(Step S2inFIG. 4). That is, the position identification unit21(seeFIG. 3) of the control unit10identifies the position of the mouth51of the user50by performing image processing on a photographed image60since the user50is in the photographed image60as shown inFIG. 8. For example, the position identification unit21obtains (X2, Y2) of the position of the mouth51of the user50.

To be more specific, the position identification unit21performs processing for detecting a face on the photographed image60to identify the face of the user50. After that, the position identification unit21partially extracts the lips from the identified face of the user50. As a method for extracting the lips, a part of an area included in the contour of the face that substantially matches a plurality of lip data stored in advance is recognized as lips, and the recognized part can be extracted as lips of the face. Further, the position identification unit21identifies the center of gravity position of the contour of the lips extracted as described above as the center point of the lips, that is, the center coordinates (X2, Y2) of the mouth51of the user50.

Next, the communication system1controls a position of the head part100so that the identified position of the mouth51of the user50is included in a region of the beam-forming (Step S3inFIG. 4). That is, as shown inFIG. 6, the communication system1controls the position of the head part100thereof so as to face downward. Accordingly, the center direction41of the beam-forming of the microphone12faces the direction of the mouth51of the user50. Thus, the position of the mouth51of the user50is included in the region of the beam-forming.

For example, the movement amount calculation unit22(seeFIG. 3) of the control unit10calculates the amount of movement of the head part100of the communication system1by using the coordinates of the position of the mouth51of the user50and the relative positional relation between the microphone12and the camera11.

Specifically, as the microphone12and the camera11are fixed to the head part100, the relative positional relation between the microphone12and the camera11is fixed. Accordingly, as shown inFIG. 8, it is possible to calculate, in the photographed image60, the relative positional relation between a center position61of the camera and a center position62(a position where the center direction41of the beam-forming is projected onto the user50) of the beam-forming by using the distance between the communication system1and the user50.

That is, it is possible to obtain the center position62(X1, Y1) of the beam-forming with respect to the center position61(X0, Y0) of the camera shown inFIG. 8by using the distance between the communication system1and the user50since an angle α formed by a center direction43of the camera11and the center direction41of the beam-forming is fixed as shown inFIG. 9.

For example, in the example shown inFIG. 9, when the position of the user50with respect to the communication system1is a position A1, a distance C between the center position61of the camera and the center position62of the beam-forming shown inFIG. 8is C1. Similarly, when the position of the user50with respect to the communication system1is a position A2(seeFIG. 9), the distance C between the center position61of the camera and the center position62of the beam-forming shown inFIG. 8is C2. In this way, it is possible to obtain the distance C between the center position61of the camera and the center position62of the beam-forming by using the distance between the communication system1and the user50.

It should be noted that the distance between the communication system1and the user50may be estimated using the size of the photographed image of the face of the user50, or the distance between the communication system1and the user50may be separately measured using a sensor such as a distance sensor or a three-dimensional position measurement sensor. When the distance between the communication system1and the user50is estimated using the size of the image of the face of the user, correlation data between the size of the image of the face of the user with an average face size on the camera image and the distance between the communication system1and the user50is input in advance. Then, it is possible to estimate the distance to a user based on the size of the image of the face of the user on the camera image taken by the camera11and the correlation data input in advance.

Note that when the center direction of the camera11and the center direction41of the beam-forming are parallel to each other, the relative positional relation between the center position61of the camera and the center position62of the beam-forming in the image60becomes constant.

As shown inFIG. 8, the coordinates of the center position61of the camera are (X0, Y0), the coordinates of the center position62of the beam-forming are (X1, Y1), and the center coordinates of the position of the mouth51of the user50are (X2, Y2). Accordingly, in this case, an amount D of movement of the head part100of the communication system1is (X2−X1, Y2−Y1).

By using such a method, the movement amount calculation unit22(seeFIG. 3) of the control unit10can calculate the amount D of movement of the head part100of the communication system1. Further, the control signal output unit23generates a control signal (i.e., a control signal of the drive unit13) corresponding to the amount D of movement of the head part100calculated by the movement amount calculation unit22and outputs the control signal to the drive unit13. Then, the drive unit13is driven in accordance with this control signal, so that the head part100is moved by the amount D of movement.

Note that in the above description, the case where the center direction41of the beam-forming of the microphone12is controlled so as to face in the direction of the mouth51of the user50has been explained. However, in this embodiment, the center direction41of the beam-forming does not necessarily have to face in the direction of the mouth51of the user50if the mouth51of the user50is included in the region of the beam-forming.

That is, inFIG. 8, a bottom surface48of the beam-forming45having a substantially conical shape shown inFIG. 2has a substantially circular shape (a shape obtained by projecting the beam-forming45having a substantially conical shape onto the user50) with the center position62of the beam-forming as the center. Accordingly, in this embodiment, the control does not necessarily have to be performed so that the center direction41of the beam-forming coincides with the position of the mouth51of the user50if the position of the mouth51of the user50is included in the bottom surface48of the beam-forming.

Next, the communication system1controls the direction of the line of sight thereof so as to face in the direction of the face of the user50(Step S4inFIG. 4). As shown inFIG. 6, when the head part100of the communication system1is moved so that the center direction41of the beam-forming of the microphone12faces the direction of the mouth51of the user50, a direction42of the line of sight of the communication system1is moved along with this movement of the head part100. As a result, the direction42of the line of sight of the communication system1deviates from the face of the user50.

As described above, if the direction42of the line of sight of the communication system1deviates from the face of the user50, an impression may be given to the user50that the communication system1is not listening to him/her. In this embodiment, as shown inFIG. 7, it is possible to prevent the impression that the communication system1is not listening to the user50from being given to the user50by controlling the direction42of the line of sight so that it faces the direction of the face of the user50(e.g., the position of the eyes). In other words, it is possible to give an impression to the user50that the communication system1is carefully listening to him/her.

For example, the control unit10may identify the position of the face of the user using the image of the user taken by the camera11and control the direction of the line of sight so as to face in the direction of the face of the user. Specifically, as shown inFIG. 8, the control unit10identifies the position of the face of the user50by performing image processing on the photographed image60. For example, the control unit may identify the positions of both eyes of the user50by performing image processing on the photographed image60, and the position of the center of both eyes may be used as a target position. The control unit10displays the eye image34on the display14so that the direction of the line of sight of the communication system1faces the target position.

Further, the control unit10may control the direction of the line of sight based on the amount of movement of the head part100when the control unit controls the position of the head part100. Specifically, in a case where the direction of the line of sight of the communication system1is adjusted to the user50in advance in the initial state shown inFIG. 5, when the head part100of the communication system1is moved, the direction42of the line of sight of the communication system1is also moved as shown inFIG. 6. This amount of movement of the direction42of the line of sight corresponds to the amount D of movement of the head part100shown inFIG. 8. Accordingly, the control unit10can adjust the direction42of the line of sight to the user50by using the amount D of movement of the head part100. That is, the control unit10performs processing for returning the line of sight upward by the amount D of movement of the head part100.

Further, the control unit10may control the direction of the line of sight by using the image of the user taken by the camera11in combination with the amount of movement of the head part100when the control unit10controls the position of the head part100.

Note that the processing (the processing for controlling the direction of the line of sight) in Step S4may be performed simultaneously with the processing (processing for controlling the position of the head part100) in Step S3. By simultaneously performing the control of the position of the head part100(Step S3) and the control of the direction of the line of sight (Step S4) as described above, it is possible to achieve a natural operation of the communication system1.

Further, the processing (the processing for controlling the direction of the line of sight) in Step S4may be omitted as appropriate. For example, the processing in Step S4may be omitted when the user50does not have a feeling of strangeness even if the line of sight of the communication system1is not moved in the processing (processing for controlling the position of the head part100) in Step S3, such as when the amount D of movement of the head part100is small.

As described above, in the communication system1according to this embodiment, the camera11configured to be able to photograph a user who is a communication partner and a microphone12configured to be able to form a beam-forming in a specific direction are provided in the head part100of the communication system1. Thus, it is possible to omit a holding unit that holds the microphone, and accordingly to make the apparatus configuration of the communication system1simple.

Further, in the communication system1according to this embodiment, a user who is a communication partner is photographed and the position of the mouth of the user is identified using the photographed image of the user. Then, the position of the head part is controlled so that the identified position of the mouth of the user is included in a region of the beam-forming of the microphone12. In this embodiment, the position of the mouth of the user is included in the region of the beam-forming of the microphone12as described above, and thus it is possible to accurately recognize a voice of the user.

Therefore, according to the disclosure of this embodiment, it is possible to provide a communication system that has a simple apparatus configuration and that can accurately recognize a voice of a user, and a method for controlling the communication system.

Further, in the communication system1according to this embodiment, the direction of the line of sight is controlled so as to face in the direction of the face of a user. Thus, it is possible to prevent the line of sight of the communication system1from deviating from the face of the user when the position of the head part100is moved. Accordingly, it is possible to give an impression (feeling of closeness) to the user50that the communication system1is listening to him/her.

Note that in the operation of the communication system1described with reference toFIG. 5 to 8, the operation in which the communication system1faces downward has been described as examples. However, in this embodiment, the communication system1may be configured so that the head part100thereof faces upward, faces left or right, and further faces in an oblique direction.

Further, in this embodiment, the communication system1may be configured so that when it moves the head part100, it also moves the arm parts37aand37b. For example, as shown inFIGS. 6 and 7, when the communication system1turns the head part100downward, the communication system1may move the arm parts37aand37bupward so that the tips of the arm parts37aand37bapproach the ear parts31aand31b. By doing so, it is possible to have the communication system1make a gesture indicating that it is carefully listening to a user.

Further, for example, when the volume of the voice of a user is lower than a predetermined volume, it is possible to inform the user that the voice of the user is quiet by having the communication system1perform an operation in which the tips of the arm parts37aand37bapproach the ear parts31aand31b.

The above description shows, as an example, the configuration in which the camera11is provided in the nose part33of the communication system1and the microphones12aand12bare provided in the ear parts31aand31bthereof. However, in this embodiment, positions where the camera11and the microphone12are provided are not limited to the above positions, and the camera11and the microphone12can be attached to any position. The present disclosure can be suitably used particularly for a small communication system (robot). Therefore, the camera11and the microphone12may be arranged at positions close to each other.

Further, in the above description, the communication system1that does not independently walk has been described. However, in this embodiment, the communication system1may be configured so that it can independently move.

FIG. 10is a block diagram showing a hardware configuration of the communication system according to this embodiment. The control unit10of the communication system1according to this embodiment includes a processor71and a memory72. Further, a program stored in the memory72(i.e., a program that can implement the operation of the control unit10) is executed by the processor71, so that the above-described operation of the control unit10can be implemented. Note that inFIG. 10, the components other than the control unit10are omitted.

Further, in the communication system according to this embodiment, a part of the operation of the control unit10may be performed in a server80(e.g., a cloud server). The server80includes a processor81and a memory82. Further, a program stored in the memory82(i.e., a program that can perform the operation of the control unit10) is executed by the processor81, so that a part of the operation of the control unit10can be performed in the server80. The communication system1is connected to the server80through a network line.

For example, the operation of the position identification unit21(seeFIG. 3) among the operations of the control unit10may be performed in the server80. That is, processing for identifying the position of the mouth of the user using the photographed image of the user may be performed in the server80. In this case, the communication system1transmits the image taken by the camera11to the server80. At this time, the communication system1may cut out the background image from the photographed image and transmit it to the server80in order to reduce the capacity of the data to be transmitted (i.e., the communication system1may transmit only the part of the image that shows a user to the server80).

Then, the server80performs image processing on the received image and identifies the position of the mouth of the user. After that, the server80transmits information about the identified position of the mouth (the coordinates of the position of the mouth) to the communication system1. The control unit10of the communication system1performs processing for calculating the amount of movement by using the received information about the position of the mouth. The subsequent operations are the same as those of the above-described communication system1, and a duplicate description is thus omitted.

Further, the server80may be connected to a plurality of communication systems1through a network line. By such a configuration, the plurality of communication systems1can be controlled (managed) using the common server80.