Wireless control apparatus using frequency modulation of inaudible sound and data communication method using thereof

Abstract

The present invention provides a wireless control unit utilizing frequency modulation of inaudible sound and a data communication method using the same, comprising: a transmitter including an audio output device that generates sound in the inaudible frequency range to the surroundings; a receiver including an audio input device that receives sound in the inaudible frequency range from the surroundings; and a control unit that executes a transmitter algorithm and a receiver algorithm.

Description

Technology Field

[0001] The present disclosure relates to a wireless control unit configured to transmit and receive data using frequency modulation of sound in the inaudible frequency range, and a data communication method using the same. Background Technology

[0003] With the recent rapid development and innovation of the Internet of Things (IoT), various technologies for wireless data transmission and reception are being proposed. Among these, the most widely used wireless communication technologies include TCP / IP communication via Wi-Fi and Bluetooth, which is used for short-range communication. However, these existing wireless communication technologies have several limitations. For example, TCP / IP communication via Wi-Fi involves environmental infrastructure and constraints, requiring dedicated communication devices such as the internet, networks, and routers; furthermore, it suffers from severe interference such as radio waves and frequent signal disruptions caused by obstacles. Bluetooth, as a short-range communication method, has clear limitations on communication distance and requires additional configuration, such as pairing between specific modules or routers; in some cases, identical OS modules are required. Consequently, existing wireless communication technologies have faced significant difficulties in application in spaces or environments with limited infrastructure (e.g., industrial sites), as they require additional technology and setup for communication.

[0004] Sound communication is the most basic and universal method of communication used by animals. Sound is transmitted directly through a medium such as air or water and requires no special environmental constraints for communication. Sound communication can contain complex and diverse information, requires low energy consumption to operate the system, and is characterized by the absence of environmental limitations compared to other communication methods. Due to these characteristics, it is attracting attention as a next-generation communication technology capable of overcoming the limitations of existing technologies, and accordingly, extensive research is being conducted.

[0005] In particular, technologies for communicating data in the form of audio signals using speakers and microphones are continuously being developed. Conventional technologies utilizing audio signals primarily propose devices or methods for communicating data using sounds within the audible frequency range; however, these technologies have the disadvantage of being highly vulnerable to security breaches and external noise.

[0006] Meanwhile, Patent Document 1, introduced as prior art in this disclosure, proposes a communication method for transmitting and receiving data by modulating and demodulating frequencies in the inaudible range using the Orthogonal Frequency Division Multiplexing (OFDM) method. However, the method proposed in Patent Document 1 has limitations in that there is a high risk of data corruption due to selective phasing of frequencies, complex signal processing such as Fast Fourier Transform (FFT) and channel estimation is required, and communication is only possible between single devices because time slots between communication devices must be set separately. Prior art literature

[0007] Korean Patent Application Publication No. 10-2010-0084675 The problem to be solved

[0008] The present disclosure aims to solve the problems of the aforementioned prior art by providing a new wireless control unit and a data communication method using the same, which overcome the limitations of existing wireless communication technology by utilizing sound in the inaudible frequency range and transmitting and receiving data through frequency modulation.

[0009] Furthermore, the present disclosure aims to provide a new wireless control unit and a data communication method using the same that enables communication between a single device and a cluster of devices and simultaneous communication between multiple devices through the separation of inaudible frequency bands.

[0010] The problems to be solved by this disclosure are not limited to the purposes mentioned above, and other unmentioned purposes will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0012] To solve the above-mentioned problem, the present disclosure provides a wireless control unit utilizing frequency modulation of inaudible sound, comprising: a transmitter including an audio output device that generates sound in an inaudible frequency range to the surroundings; a receiver including an audio input device that receives sound in an inaudible frequency range from the surroundings; and a control unit that executes a transmitter algorithm and a receiver algorithm, wherein in the transmitter algorithm, the control unit converts original information to be transmitted into an audio signal through an inaudible frequency modulation algorithm and transmits the converted audio signal to the surroundings through the audio output device, and in the receiver algorithm, the control unit converts the audio signal received from the audio input device into original information through a predetermined signal processing algorithm.

[0013] An inaudible frequency modulation algorithm may convert original information into an audio signal through a frequency modulation method using one or more of frequency, frequency modulation range, and frequency modulation time as parameters.

[0014] The source information includes one or more control commands for controlling a device equipped with a wireless control unit, and one or more control commands may be assigned to each parameter.

[0015] The frequency, frequency modulation range, and frequency modulation time may each correspond to one of the control commands: a robot movement command, a robot movement speed, and a robot movement time. In the transmitting algorithm, the control unit may set a unique inaudible frequency range before converting the original information into an audio signal, and convert the original information to be transmitted into an audio signal of the set unique inaudible frequency range.

[0016] In the receiving algorithm, the control unit separates the inaudible frequency range to be received into one or more inaudible frequency ranges and can process signals received from each inaudible frequency range separately.

[0017] Each range of the inaudible frequency band to be received can be 2 to 4 kHz.

[0018] The audio output device is a commercial speaker, and the audio input device can be a commercial microphone.

[0019] The inaudible frequency range may be a frequency range of 18 kHz or higher.

[0020] The wireless control unit may be controlled in an indoor space.

[0021] An additional embodiment of the present disclosure provides a method for one-to-one or one-to-multiple data communication using frequency modulation of inaudible sound, comprising: providing a reader device including a wireless control unit having the configuration described above and one or more follower devices; setting a unique inaudible frequency range in a control unit of the reader device; converting original information to be transmitted in the control unit of the reader device into an audio signal in the unique inaudible frequency range of the reader device through an inaudible range frequency modulation algorithm; outputting the converted audio signal to the outside through an audio output device; setting the unique inaudible frequency range of the reader device into a frequency range to be received in the control unit of each follower device; receiving the audio signal in the unique inaudible frequency range of the reader device at an audio input device of each follower device; converting the received audio signal into original information through a predetermined signal processing algorithm in the control unit of each follower device; and controlling the follower devices according to control commands included in the original information.

[0022] Another additional embodiment of the present disclosure comprises the steps of: providing three or more devices including a wireless control unit comprising the configuration described above; separating inaudible frequency ranges into a plurality of ranges so as not to overlap with each other and assigning them to each device, wherein each device sets the inaudible frequency range assigned to itself as its own unique inaudible frequency range and remembers the inaudible frequency ranges assigned to the remaining devices excluding itself; converting original information to be transmitted into an audio signal of the device's unique inaudible frequency range through an inaudible frequency modulation algorithm in a control unit of one of the three or more devices; outputting the converted audio signal externally through an audio output device of one of the three or more devices' wireless control unit; separating the inaudible frequency ranges assigned to the remaining devices excluding itself in a control unit of each of the remaining devices among the three or more devices and setting them as frequency ranges to be received; and receiving an audio signal from an audio input device of each of the remaining devices' wireless control unit. A method for multiple-to-multiple simultaneous data communication using frequency modulation of inaudible sound is provided, comprising the steps of: converting an audio signal received from a control unit of a wireless control unit of each of the remaining devices among three or more devices into original information through a predetermined signal processing algorithm; and controlling each device according to a control command included in the original information.

[0023] Another additional embodiment of the present disclosure may be a wireless control system comprising two or more wireless control units of the configuration described above. Effects of the invention

[0025] According to a wireless control unit of one embodiment of the present disclosure, unlike conventional wireless communication technology, no separate infrastructure (e.g., a dedicated communication device) is required, so communication and machine control are possible in various spaces without special environmental constraints.

[0026] In addition, according to one embodiment of the present disclosure, a wireless control unit utilizes sound in an inaudible frequency range that is inaudible to humans, thereby reducing security threats caused by external listening or interference, ensuring security, and also has the effect of enabling safe use as it is not harmful to the human body.

[0027] Furthermore, according to one embodiment of the present disclosure, a wireless control unit transmits data directly through a medium (air, water, etc.), thereby enabling information transmission over relatively long distances, and has the effect of very high transmission speed and significantly low latency. In addition, since a frequency modulation method is used, complex information can be transmitted without loss, so it can be utilized in fields requiring delicate machine control.

[0028] In addition, by separating the inaudible frequency bands used for communication by device, single-machine and multi-machine communication / control is possible with a single communication device. Furthermore, since the inaudible frequency band has a wide range, there is an advantage in that multiple devices can communicate simultaneously without loss.

[0029] However, the effects of the present disclosure are not limited to those described above, but include all effects naturally realized through the various configurations proposed in the present disclosure. Brief explanation of the drawing

[0031] The features and benefits of the preferred embodiments of the present disclosure will become more apparent from the following description, which is discussed in conjunction with the accompanying drawings. FIG. 1 is a schematic diagram illustrating the configuration of a wireless control unit according to one embodiment of the present disclosure. Figure 2(a) is a flowchart showing the transmitting algorithm, and Figure 2(b) is a flowchart showing the receiving algorithm. FIG. 3 is a schematic diagram illustrating an example of communication between two wireless control units, each set to a different unique inaudible frequency range. Figure 4 is a diagram showing an example of an inaudible range frequency modulation algorithm that converts original information into an audio signal using one or more of frequency, frequency modulation range, and frequency modulation time as parameters. Figure 5(a) schematically shows an example of a signal processing algorithm performed in a receiver algorithm, and Figure 5(b) is a flowchart of the signal processing algorithm according to this example. FIG. 6 schematically illustrates an example of a communication method between a single device and a cluster of devices, and a simultaneous communication method between multiple devices, including a wireless control unit according to one embodiment of the present disclosure. FIG. 7 shows the results of a robustness test against a noise environment of a wireless control unit according to one embodiment of the present disclosure. FIG. 8 shows a hypothetical application example using a wireless control unit according to one embodiment of the present disclosure. FIG. 9 illustrates a hypothetical application example of data communication between a single device and a cluster of devices using a wireless control unit according to an embodiment of the present disclosure that was actually implemented, wherein (a) is a field photograph taken by the inventors of the present disclosure during an actual experiment, and (b) shows the results of evaluating the accuracy of the communication performed in this experiment according to the communication distance. Specific details for implementing the invention

[0032] The embodiments of the present disclosure are illustrative for the purpose of explaining the technical concept of the present disclosure. The scope of rights according to the present disclosure is not limited to the embodiments presented below or the specific description thereof.

[0033] All technical and scientific terms used in this disclosure, unless otherwise defined, have the meaning generally understood by those skilled in the art to which this disclosure pertains. All terms used in this disclosure are selected for the purpose of further clarifying this disclosure and are not selected to limit the scope of the rights under this disclosure.

[0034] Expressions such as “comprising,” “comprising,” “having,” etc. used in this disclosure should be understood as open-ended terms implying the possibility of including other embodiments, unless otherwise stated in the phrase or sentence containing such expressions.

[0035] In the present disclosure, when a part such as a layer, film, region, or plate is described as being "on" or "on" another part, this includes not only cases where it is "immediately above" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately above" another part, it means that there is no other part in between. Furthermore, being described as being "on" or "on" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "on" in the direction opposite to gravity. The same applies to "below" or "under."

[0036] In the present disclosure, "planar view" refers to the subject of the present disclosure as viewed from above, and "cross-sectional view" refers to the subject of the present disclosure as viewed from the side by cutting a cross-section perpendicular to the ground or installation surface. Additionally, in the present disclosure, "front view" refers to the part visible from the front or front, and "rear view" refers to the side opposite to the "front view."

[0037] In this disclosure, expressions such as "identical" and "identical" indicate not only a strictly identical state, but also a state in which tolerances or differences exist to the extent that the same function is obtained.

[0038] In this disclosure, expressions indicating relative or absolute arrangements, such as “in a certain direction,” “along a certain direction,” “parallel,” “perpendicular,” “to the center,” “concentric,” or “coaxial,” strictly indicate such arrangements, as well as states of relative displacement with respect to tolerances or angles or distances to which the same function is obtained.

[0039] Unless otherwise stated, singular expressions described in this disclosure may include a plural meaning, and this applies likewise to singular expressions described in the claims.

[0041] Embodiments of the present disclosure will be described below with reference to the attached drawings. In this process, the thickness of lines or the size of components depicted in the drawings may be exaggerated for clarity and convenience of explanation. Furthermore, in the description of the embodiments below, the description of identical or corresponding components may be omitted. However, the omission of a description of a component is not intended to imply that such component is not included in any embodiment.

[0042] In addition, the following embodiments are not intended to limit the scope of the rights of the present disclosure but are merely exemplary details of the components presented in the claims of the present disclosure, and embodiments including components that are included in the technical concept throughout the specification of the present disclosure and are substitutable as equivalents for the components of the claims may be included in the scope of the rights of the present disclosure.

[0044] Wireless control unit

[0045] FIG. 1 schematically illustrates the configuration of a wireless control unit using frequency modulation of inaudible sound according to one embodiment of the present disclosure. Referring to FIG. 1, a wireless control unit according to one embodiment of the present disclosure includes: a transmitter including an audio output device that generates sound in the inaudible frequency range to the surroundings; a receiver including an audio input device that receives sound in the inaudible frequency range from the surroundings; and a control unit that executes a transmitter algorithm and a receiver algorithm. This wireless control unit may be mounted on a device such as a robot or a mechanical device and configured to control the device through data transmission and reception with the outside.

[0047] A wireless control unit according to one embodiment of the present disclosure comprises a transmitter including an audio output device. Sound can be classified into audible frequency sounds that humans can hear and inaudible frequency sounds that humans cannot hear (generally frequencies of 18 kHz or higher). The audio output device is configured to output sound in this inaudible frequency range, that is, inaudible frequency sounds having a frequency of 18 kHz or higher. As a non-limiting embodiment, the audio output device may include any one of an ultrasonic generator, an ultrasonic speaker, a resonator, and a commercial speaker. Additionally, the transmitter may further include, as necessary, a signal generator, an audio interface, and a processor for frequency allocation and signal processing.

[0049] A wireless control unit according to one embodiment of the present disclosure also comprises a receiver including an audio input device. The audio input device is configured to receive sound in the inaudible frequency range. In a non-limiting embodiment, the audio input device may include any one of an ultrasonic microphone, an ultrasonic detector, an ultrasonic camera, a non-contact optical laser sensor, and a commercial microphone. Additionally, the receiver may further include an audio interface, a processor for signal processing, etc., as needed.

[0051] A wireless control unit according to one embodiment of the present disclosure includes a control unit configured to process a transmitter algorithm and a receiver algorithm. FIG. 2(a) and FIG. 2(b) respectively illustrate flowcharts of a transmitter algorithm and a receiver algorithm. However, the transmitter algorithm and the receiver algorithm are not limited to the flowcharts illustrated in FIG. 2 and may include additional steps depending on specific conditions such as an actual execution environment.

[0053] A wireless control unit according to one embodiment of the present disclosure may be used in an indoor space for the accuracy of transmitting and receiving control signals. In addition, when applied to a data communication method between a single device and a single device or between a single device and a cluster of devices, it may be preferable that the mutual distance between devices be within 10m.

[0055] Transmitter algorithm

[0056] First, FIG. 2(a) shows a flowchart of the transmitter algorithm. Referring to FIG. 2(a), in the transmitter algorithm, the control unit sets the unique inaudible frequency range of the corresponding wireless control unit (TS1). Here, the unique inaudible frequency range can be defined as the inaudible frequency range allocated for the wireless control unit to use for communication. If there are two or more wireless control units, it is desirable to separate and allocate the unique inaudible frequency ranges of each wireless control unit so that they do not overlap with one another.

[0057] By setting unique inaudible frequency ranges, interference in communication between two or more wireless control units can be minimized. As an example, FIG. 3 schematically illustrates communication between two wireless control units set to different unique inaudible frequency ranges. As shown in FIG. 3, if inaudible frequency ranges are separated without overlap and assigned to each wireless control unit, interference does not occur between the transmission signal of the first device (Device 1) and the transmission signal of the second device (Device 2), and the signals can reach the other device intact.

[0058] In addition, by setting a unique inaudible frequency range, simultaneous communication between multiple devices in which three or more wireless control units participate in communication may also be possible. For example, when simultaneous communication is performed between three devices, the first wireless control unit of the first device sets a unique inaudible frequency range of 18 kHz or more and less than 20 kHz, the second wireless control unit of the second device sets a unique inaudible frequency range of 20 kHz or more and less than 22 kHz, and the third wireless control unit of the third device sets a unique inaudible frequency range of 22 kHz or more and less than 24 kHz, thereby enabling real-time communication between each device without interference.

[0060] Next, the control unit converts the original information to be transmitted into an audio signal through an inaudible frequency modulation algorithm (TS2).

[0061] The source information may include one or more control commands for controlling a device equipped with a wireless control unit according to one embodiment of the present disclosure, such as a robot or a cart. In a non-limiting embodiment, the control command may be a command regarding the movement method of the device equipped with the wireless control unit. For example, it may be forward, backward, (left / right) turn, turn, straight, curved movement, diagonal movement, acceleration, deceleration, lateral movement, stop, or a combination thereof.

[0062] In the transmitting algorithm, the control unit converts the original information into an audio signal according to an inaudible frequency modulation algorithm pre-entered into the wireless control unit. Since the logic of the inaudible frequency modulation algorithm needs to be set differently depending on the application field, the logic of the inaudible frequency modulation algorithm is not specifically limited in this disclosure.

[0063] As a non-limiting embodiment, an inaudible frequency modulation algorithm may be configured to convert original information into an audio signal using one or more of frequency, frequency modulation range, and frequency modulation time as parameters. Referring to FIG. 4, FIG. 4 assumes a robot transfer control situation, and as shown in the table on the left of FIG. 4, one or more control commands for controlling the device are assigned to each of the parameters: frequency, frequency modulation range, and frequency modulation time. More specifically, the inaudible frequency modulation algorithm is configured with logic in which a sound of frequency 18 kHz is used as a robot movement command, the forward speed is set to 100% of the maximum speed when the frequency modulation range increases by 1 kHz, the movement time to that speed is defined according to the frequency modulation time, and a sound of frequency 19 kHz is used as a robot stop command. An example of an inaudible audio signal converted according to such an algorithm is shown on the right side of FIG. 4. It should be noted that the inaudible frequency modulation algorithm illustrated in FIG. 4 is merely an example to more easily explain the present disclosure, and the inaudible frequency modulation algorithm executed in the transmitter algorithm of the present disclosure is not limited to that illustrated in FIG. 4.

[0064] The converted audio signal is then output to the surroundings through an audio output device provided in the transmitter to transmit to another device (TS3).

[0066] Receiver algorithm

[0067] Figure 2(b) shows a flowchart of the receiver algorithm. Referring to Figure 2(b), in the receiver algorithm, the control unit first separates the inaudible frequency range for each transmitting device (RS1).

[0068] At this time, the control unit can separate the inaudible frequency range to correspond to the unique inaudible frequency ranges of the devices participating in the communication. To explain using the example of simultaneous communication between three devices mentioned earlier, the first wireless control unit separates the inaudible frequency range into a frequency range of 18 kHz or more and less than 20 kHz, a frequency range of 20 kHz or more and less than 22 kHz, and a frequency range of 22 kHz or more and less than 24 kHz, and recognizes and processes the frequency range of 20 kHz or more and less than 22 kHz and the frequency range of 22 kHz or more and less than 24 kHz as signals from the second wireless control unit and the third wireless control unit, respectively. Similarly, the second wireless control unit separates the inaudible frequency range into a frequency range of 18 kHz or more and less than 20 kHz, a frequency range of 20 kHz or more and less than 22 kHz, and a frequency range of 22 kHz or more and less than 24 kHz, and processes the frequency range of 18 kHz or more and less than 20 kHz and the frequency range of 22 kHz or more and less than 24 kHz by recognizing them as signals from the first wireless control unit and the third wireless control unit, respectively. Also similarly, the third wireless control unit separates the inaudible frequency range into a frequency range of 18 kHz or more and less than 20 kHz, a frequency range of 20 kHz or more and less than 22 kHz, and a frequency range of 22 kHz or more and less than 24 kHz, and processes the frequency range of 18 kHz or more and less than 20 kHz and the frequency range of 20 kHz or more and less than 22 kHz by recognizing them as signals from the first wireless control unit and the second wireless control unit, respectively. In this way, the control unit separates the reception range of inaudible frequencies into one or more inaudible frequency ranges and processes signals received from each inaudible frequency range separately, thereby enabling real-time communication between multiple devices without overlap. In addition, since the range of inaudible frequencies is very wide, there are no practical limitations on the number of devices.

[0069] As a non-limiting example, the range of each inaudible frequency band can be separated to 1 to 2 kHz.

[0071] Next, the control unit receives audio signals from each separated inaudible frequency band through the audio input device (RS2).

[0072] Subsequently, the control unit converts the audio signals received individually for each separated inaudible frequency range into original information through a signal processing algorithm (RS3).

[0073] A signal processing algorithm is an algorithm used in the process of restoring an audio signal, converted by an inaudible frequency modulation algorithm of a transmitting device, back to the original information. In other words, the signal processing algorithm plays the role of demodulating the signal converted by the inaudible frequency modulation algorithm to return it to the original information.

[0075] As a non-limiting example, in the case where the frequency is modulated using an example of the inaudible range frequency modulation algorithm of FIG. 4 presented above, namely, "a sound of 18 kHz as a robot movement command, a forward speed as 100% of the maximum speed as the frequency modulation range increases by 1 kHz, a movement time to that speed is defined according to the frequency modulation time, and a sound of 19.0 kHz as a robot stop command," an example of a signal processing algorithm is as follows, and a schematic diagram and flowchart thereof are shown in FIG. 5 (a) and (b), respectively.

[0076] Referring to Fig. 5, first, signals entering the audio input device are received in 10 ms increments, and the dominant frequency of the signal of that length is identified. The dominant frequency can be detected using signal processing algorithms such as Fast-Fourier Transform (FFT) and peak selection. If the dominant frequency is 18 kHz, which was previously set as the robot movement command, and is detected for a specific time (e.g., 50 ms) or longer (the "start token" in Fig. 5 (a)), the subsequent signal (sound) is recognized as a detailed command signal (forward distance, movement time, etc.) related to the robot movement command. The detailed robot movement command signal is identified through changes in the dominant frequency of the signals received in 10 ms increments, and the change is detected until a sound with a dominant frequency of 19 kHz, which was previously set as the robot stop command, is detected for a specific time or longer. For example, as shown in Fig. 5(a), if the dominant frequency of the sound changes from 18 kHz to 19 kHz for 50 ms, the robot recognizes a forward command for 50 ms at 100% of the maximum speed through a signal processing algorithm.

[0078] Now, a one-to-one data communication method, a one-to-multiple data communication method, and a multiple-to-multiple simultaneous data communication method using a wireless control unit according to the present disclosure will be described in detail by example. However, it should be noted that the data communication method described below is merely an example to facilitate the explanation of the present disclosure, and the communication method using the wireless control unit according to the present disclosure is not limited to the following.

[0080] One-to-One data communication method

[0081] First, a first device and a second device comprising a wireless control unit configured as described above are provided, and the case where the first device is a device that transmits a signal and the second device is a device that receives a signal is explained as an example. Naturally, the same data communication method may also be applied in the opposite case, that is, when the second device transmits a signal and the first device receives a signal.

[0082] The first device transmits an audio signal in the inaudible frequency range to the second device according to a transmitter algorithm. Specifically, first, a control unit in the first device sets a unique inaudible frequency range, and the control unit of the first device converts the original information to be transmitted into an audio signal in the unique inaudible frequency range of the first device through a pre-entered inaudible frequency modulation algorithm. Subsequently, the first device outputs the converted audio signal externally through an audio output device.

[0083] The second device processes an audio signal in the inaudible frequency range transmitted from the first device according to a receiving algorithm. Specifically, the second device first separates the unique inaudible frequency range of the first device and sets it as the frequency range to be received. Then, the second device receives the audio signal in the unique inaudible frequency range of the first device through an audio input device.

[0084] The control unit of the second device converts the received audio signal into original information through a predetermined signal processing algorithm and controls the second device according to control commands included in the original information.

[0086] One-to-Multiple data communication method

[0087] First, a first device comprising a wireless control unit configured as described above and a plurality of second devices are provided, wherein the first device is defined as a reader device that transmits a signal and the second device is defined as a follower device that receives a signal.

[0088] The first device (reader device) transmits a signal in the corresponding unique inaudible frequency range toward a plurality of second devices (follower devices) according to the transmitting algorithm. Specifically, first, the control unit of the first device sets the unique inaudible frequency range, and the control unit of the first device converts the original information to be transmitted into an audio signal in the unique inaudible frequency range of the first device through an inaudible frequency modulation algorithm. Subsequently, the first device outputs the converted signal externally through an audio output device.

[0089] Each of the multiple second devices processes a signal in the inaudible frequency range transmitted from the first device according to a receiving algorithm. Specifically, first, each second device separates the unique inaudible frequency range of the first device and sets it as the frequency range to be received. Then, each second device receives an audio signal in the unique inaudible frequency range of the first device through an audio input device.

[0090] The control unit of each second device converts the received audio signal into original information through a predetermined signal processing algorithm and controls the corresponding second device according to the control command included in the original information.

[0092] Multiple-to-Multiple Simultaneous Data Communication Method

[0093] First, three or more devices comprising a wireless control unit configured as described above are provided. Next, the inaudible frequency range is divided into multiple ranges so as not to overlap with one another, and these ranges are assigned to each device. Each device sets the inaudible frequency range assigned to it as its own unique inaudible frequency range and remembers the inaudible frequency ranges assigned to the remaining devices excluding itself.

[0094] One of the three or more devices converts the original information to be transmitted from the control unit of the wireless control unit into an audio signal in the device's unique inaudible frequency range using an inaudible frequency modulation algorithm. Subsequently, the wireless control unit of the device outputs the converted audio signal to the outside through an audio output device.

[0095] Each of the remaining devices among the three or more devices separates the inaudible frequency range into the inaudible frequency range assigned to the remaining devices excluding itself, and sets each as the frequency range to be received. Then, each of the remaining devices among the three or more devices receives an audio signal output from one of the three or more devices through an audio input device. Each of the remaining devices among the three or more devices converts the audio signal received from the control unit of the wireless control unit into original information through a predetermined signal processing algorithm, interprets the control command included in the original information, and controls the corresponding device according to the control command.

[0097] Examples

[0098] (Experiment 1) Robustness test against a noisy environment

[0099] The inventors of the present disclosure confirmed the robustness of a wireless control unit according to one embodiment of the present disclosure against a noisy environment using the following experimental method.

[0100] First, a receiver module, two transmitter modules set to different unique inaudible frequency ranges (18 kHz, 20 kHz), and a noise source configured to generate noise including factory and street noise were prepared. Then, the noise source and the two transmitter modules were placed at a distance of 2 m from the receiver module. Sound was simultaneously output from the noise source and the two transmitter modules at the same sound pressure (84.5 dB), and it was verified whether the receiver module accurately received the data sent from the two transmitter modules.

[0101] Figure 7 shows the experimental results obtained using the experimental method described above in a semi-anechoic room. The spectrogram in Figure 7 shows that both the inaudible sound at 18 kHz and the inaudible sound at 20 kHz transmitted from the transmitting module were robustly transmitted to the receiving module, regardless of the presence or absence of noise generated from the noise source.

[0102] From these experimental results, it can be confirmed that the communication method using a wireless control unit according to one embodiment of the present disclosure transmits data robustly without being affected by external noise, and furthermore, by separating the inaudible frequency range, communication between multiple devices is also possible.

[0104] (Experiment 2) Virtual application example using a wireless control unit according to one embodiment of the present disclosure

[0105] FIG. 8 illustrates a virtual application example using a wireless control unit according to one embodiment of the present disclosure. The inventors of the present disclosure constructed a virtual factory environment and demonstrated a wireless robot control situation using inaudible sounds in this factory environment. Specifically, a situation was established in which a leader robot controls a follower robot that receives control information through the transmission of control information to perform a command to rescue a person in the factory environment and reach the leader robot. In the inaudible frequency modulation algorithm of this demonstration, an inaudible sound of 18 kHz frequency was defined as the command "Move Now" and an inaudible sound of 20 kHz frequency was defined as the command "Come Here".

[0106] From the spectrogram of Fig. 8, it can be confirmed that in this demonstration, despite various obstacles, the follower robot accurately received the commands of the leader robot, 'Move Now' and 'Come Here,' through the data communication method via the wireless control unit proposed in this disclosure.

[0108] (Experiment 3) A hypothetical application example of data communication between a single device and a cluster of devices according to one embodiment of the present disclosure

[0109] The inventors of the present disclosure conducted an experiment to measure the accuracy of data communication between a single device and a cluster of devices using a wireless control unit according to one embodiment of the present disclosure.

[0110] First, as shown in Fig. 9(a), a total of four robots were prepared, and each robot was equipped with a receiver module and a control module for signal processing. Then, an identification code (AMR, Cobot, LeeAhn2, Cobot2) was assigned to each robot. The four robots were placed at approximately the same location, and a loudspeaker was placed at a predetermined distance from this location. Commands for various robot movements (drive of the robot arm x, y, z axes / drive of the mobile robot forward, backward, rotation, etc.) were simultaneously transmitted to each robot through sound in the inaudible frequency range output from the loudspeaker.

[0111] Figure 9(b) shows the accuracy of the communication performed in this experiment evaluated according to the communication distance. As can be easily seen in Figure 9(b), in both cases where a command was sent to only one robot (k=1, single-device communication) and where a command was sent to all four robots (k=4, single-cluster communication), an accuracy of over 99% was shown at a short distance (1 m) and over 98% was shown at a relatively long distance (4 m), confirming that stable and accurate communication is possible even in single-cluster communication controlling multiple devices simultaneously.

[0113] The foregoing description is merely an illustrative explanation of the technical concept of the present disclosure, and those skilled in the art to which the present disclosure pertains may make various modifications and variations within the scope of the essential characteristics of the present disclosure. Accordingly, the embodiments disclosed in the present disclosure are intended to explain, not limit, the technical concept of the present disclosure, and the scope of the technical concept of the present disclosure is not limited by such embodiments. The scope of protection of the present disclosure shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present disclosure. Explanation of the symbols

[0115] 10 devices 100 wireless control units 110 Transmitter 111 Audio Output Device 120 receiver 121 Audio Input Device 130 Control Unit

Claims

Claim 1 A wireless control unit utilizing frequency modulation of inaudible sound, comprising: a transmitter including an audio output device that generates sound in the inaudible frequency range to the surroundings; and a receiver including an audio input device that receives sound in the inaudible frequency range from the surroundings. A wireless control unit comprising a control unit that executes a transmitting unit algorithm and a receiving unit algorithm, wherein in the transmitting unit algorithm, the control unit sets a unique inaudible frequency range before converting original information to be transmitted into an audio signal, converts the original information to be transmitted into an audio signal of the set unique inaudible frequency range through an inaudible range frequency modulation algorithm, and transmits the converted audio signal to the surroundings through the audio output device, wherein the inaudible range frequency modulation algorithm converts the original information into an audio signal through a frequency modulation method using one or more parameters among frequency, frequency modulation range, and frequency modulation time, wherein the original information includes one or more control commands for controlling a device equipped with the wireless control unit, and one or more control commands are assigned to each parameter, and in the receiving unit algorithm, the control unit separates the inaudible frequency range to be received into one or more inaudible frequency ranges, processes signals received from each inaudible frequency range separately from one another, and converts the audio signal received from the audio input device into original information through a predetermined signal processing algorithm. Claim 2 delete Claim 3 delete Claim 4 A wireless control unit in which, in claim 1, one or more control commands are assigned to each parameter, wherein the frequency, frequency modulation range, and frequency modulation time each correspond to one of a control command among a robot movement command, a robot movement speed, and a robot movement time. Claim 5 delete Claim 6 delete Claim 7 A wireless control unit according to claim 1, wherein each range of the inaudible frequency band to be received is 1 to 2 kHz. Claim 8 A wireless control unit according to claim 1, wherein the audio output device is a commercial speaker and the audio input device is a commercial microphone. Claim 9 A wireless control unit according to claim 1, wherein the inaudible frequency range is a frequency range of 18 kHz or higher. Claim 10 In paragraph 1, the wireless control unit is a wireless control unit that is controlled in an indoor space. Claim 11 A data communication method for one-to-one or one-to-multiple devices using frequency modulation of inaudible sound, comprising: providing a reader device including a wireless control unit according to claim 1 and one or more follower devices; setting a unique inaudible frequency range in a control unit of the reader device; converting original information to be transmitted in the control unit of the reader device into an audio signal in the unique inaudible frequency range of the reader device through an inaudible range frequency modulation algorithm; outputting the converted audio signal to the outside through an audio output device; setting the unique inaudible frequency range of the reader device as a frequency range to be received in the control unit of each follower device; receiving the audio signal in the unique inaudible frequency range of the reader device at an audio input device of each follower device; converting the received audio signal into original information through a predetermined signal processing algorithm in the control unit of each follower device; and controlling each follower device according to a control command included in the original information. Claim 12 A method for multiple-to-multiple simultaneous data communication using frequency modulation of inaudible sound, comprising: providing three or more devices including a wireless control unit according to claim 1; separating inaudible frequency ranges into multiple ranges so as not to overlap with each other and assigning them to each device, wherein each device sets the inaudible frequency range assigned to itself as its own unique inaudible frequency range and remembers the inaudible frequency ranges assigned to the remaining devices excluding itself; converting original information to be transmitted into an audio signal of the device's unique inaudible frequency range through an inaudible range frequency modulation algorithm in a control unit of one of the three or more devices; outputting the converted audio signal externally through an audio output device of one of the three or more devices' wireless control unit; separating the inaudible frequency ranges assigned to the remaining devices excluding itself in a control unit of each of the remaining devices among the three or more devices and setting them as frequency ranges to be received; receiving the audio signal in an audio input device of each of the remaining devices' wireless control unit among the three or more devices; and the three or more A data communication method comprising: a step of converting an audio signal received from a control unit of a wireless control unit of each of the remaining devices into original information through a predetermined signal processing algorithm; and a step of controlling each device according to a control command included in the original information. Claim 13 A wireless control system comprising two or more wireless control units according to paragraph 1.

Images