JP2021012095A - Sensor terminal - Google Patents

Abstract

To provide a sensor terminal capable of surely specifying the transmission source of a sound wave signal.SOLUTION: According to an embodiment, a sensor terminal includes a signal reception part and a processor. The signal reception part acquires a reception signal obtained by converting a sound wave to be received by an ultrasonic sensor into an electric signal. The processor analyses a frequency component of the reception signal acquired by the signal reception part, and specifies identification information included in the reception signal on the basis of an analysis result of the frequency component of the reception signal.SELECTED DRAWING: Figure 2

Description

Embodiments of the present invention relate to sensor terminals.

In recent years, in industrial systems used in logistics, distribution, manufacturing sites, etc., the introduction of robots has been actively promoted in order to improve work efficiency. For example, various robots such as arm robots for assembling products and automatic guided vehicles (AGV) for transportation are being introduced. It is necessary to control such a robot so as not to collide with a person or an object other than the work target. For example, there is a system in which a dedicated work area or rail is provided in order to prevent the robot from colliding with a person or an object other than the work target.

In addition, as a method for the robot to prevent collision, the presence of a nearby object is detected by the reflected wave of the ultrasonic signal output by the ultrasonic sensor installed in the robot, and the operation is stopped when a person or an object not to be worked is approached. There are methods such as slowing down or slowing down. For example, an arm robot that loads products can prevent collisions with transparent or black objects that camera images are not good at by detecting objects to be loaded with ultrasonic sensors. However, the problem of ultrasonic sensing is that in an environment where multiple robots exist or in an environment where ultrasonic waves are generated due to vibration of a machine, the distance is erroneously estimated by an ultrasonic signal other than the one output by the robot. There is.

In addition, if an ultrasonic signal other than the one output by the user makes an erroneous estimation, by assigning a frequency unique to each robot as the frequency of the ultrasonic signal to be output, it can be determined whether the signal is transmitted by the user from the received frequency. Judgment operation is conceivable. However, the ultrasonic element used in a general ultrasonic sensor has a reception sensitivity concentrated on a specific frequency such as 40 kHz, and the band of the receivable frequency is narrow. Therefore, the ultrasonic element has a narrow range in which the frequency can be changed, and there is a problem that it is difficult to cope with the simultaneous operation of a plurality of robots.

Japanese Unexamined Patent Publication No. 10-40491

An object to be solved by the present invention is to provide a sensor terminal capable of identifying the source of a sound wave signal with high accuracy.

According to the embodiment, the sensor terminal has a signal receiving unit and a processor. The signal receiving unit acquires a received signal obtained by converting the sound wave received by the ultrasonic sensor into an electric signal. The processor analyzes the frequency component of the received signal acquired by the signal receiving unit, and identifies the identification information included in the received signal based on the analysis result of the frequency component of the received signal.

FIG. 1 is a diagram showing a configuration example of an industrial system including a sensor terminal according to the first embodiment. FIG. 2 is a block diagram showing a configuration example of the sensor terminal according to the first embodiment. FIG. 3 is a diagram showing an example of a signal processed by the sensor terminal according to the first embodiment. FIG. 4 is a flowchart for explaining an operation example of the sensor terminal according to the first embodiment. FIG. 5 is a diagram showing a configuration example of an industrial system including a sensor terminal according to a second embodiment. FIG. 6 is a block diagram showing a configuration example of the sensor terminal according to the second embodiment. FIG. 7 is a block diagram showing a configuration example of the signal transmission device according to the second embodiment. FIG. 8 is a flowchart for explaining a process transmitted by the signal transmission device according to the second embodiment. FIG. 9 is a flowchart for explaining an operation example of the sensor terminal according to the second embodiment. FIG. 10 is a diagram for explaining a representation example of ID information in a signal received by a sensor terminal as a first modification. FIG. 11 is a diagram for explaining a representation example of ID information in a signal received by a sensor terminal as a first modification. FIG. 12 is a diagram for explaining a representation example of ID information in a signal received by the sensor terminal as a second modification. FIG. 13 is a diagram for explaining a representation example of ID information in a signal received by the sensor terminal as a second modification. FIG. 14 is a diagram for explaining a case where the signal received by the sensor terminal is normal as a second modification. FIG. 15 is a diagram for explaining a case where the signal received by the sensor terminal is not normal as a second modification. FIG. 16 is a diagram for explaining a representation example of ID information in a signal received by a sensor terminal as a third modification. FIG. 17 is a diagram for explaining a representation example of ID information in a signal received by the sensor terminal as a third modification. FIG. 18 is a diagram for explaining a representation example of ID information in a signal received by the sensor terminal as a fourth modification. FIG. 19 is a diagram for explaining a representation example of ID information in a signal received by the sensor terminal as a fourth modification. FIG. 20 is a diagram for explaining a representation example of ID information in a signal received by a sensor terminal as a fourth modification.

Hereinafter, embodiments will be described with reference to the drawings.
(First Embodiment)
First, the first embodiment will be described.
FIG. 1 is a diagram schematically showing a configuration example of an industrial system including the sensor terminals 1 (1A, 1B) according to the first embodiment.
The sensor terminal 1 is a device that measures the distance between its own position and surrounding objects. For example, the sensor terminal 1 is mounted on a moving moving body and measures the distance between a surrounding object and the moving body. In the configuration example shown in FIG. 1, the sensor terminals 1 (1A, 1B) are mounted on a robot 2 such as an automatic guided vehicle (AGV) 2A or an arm robot 2B as a moving body.

Further, the industrial system shown in FIG. 1 assumes an operation mode in which a person P such as a worker exists within the range in which the robot 2 operates. The sensor terminal 1 mounted on the robot 2 detects a person (worker) P or an obstacle existing in the vicinity of the robot 2 and measures the distance to the person P or the obstacle existing in the vicinity. For example, the robot 2 controls the movement according to the distance to the person P measured by the sensor terminal 1 to perform the movement control so as to avoid contact with the person P.

FIG. 2 is a block showing a configuration example of the sensor terminal 1 according to the first embodiment.
In the configuration example shown in FIG. 2, the sensor terminal 1 includes an ultrasonic sensor 11, a signal creation unit 12, a signal transmission unit 13, a signal reception unit 14, a filter processing unit 15, a signal determination unit 16, a distance measuring unit 17, and a communication unit. It has 18 and a display unit 19.

In the configuration example shown in FIG. 2, the signal creation unit 12, the filter processing unit 15, the signal determination unit 16, and the distance measuring unit 17 are functions realized by the processor 21 executing a program. That is, the signal creation unit 12, the filter processing unit 15, the signal determination unit 16, and the distance measuring unit 17 are configured as a processing device having a processor 21, a memory, and the like. However, the signal creation unit 12, the filter processing unit 15, the signal determination unit 16, and the distance measuring unit 17 may be realized by different hardware.

The ultrasonic sensor 11 vibrates in response to an input from the signal transmission unit 13 and outputs a transmission signal into the air. Further, when there is no input from the signal transmission unit 13, the ultrasonic sensor 11 converts the vibration in the air into an electric potential. The ultrasonic sensor 11 may be provided with a separate ultrasonic sensor for transmission and an ultrasonic sensor for reception so that transmission and reception can be performed at the same time.

The signal creation unit 12 creates signal information for transmission to be supplied to the signal transmission unit 13 for the ultrasonic sensor 11 to output a signal. The signal creation unit 12 includes information on a signal wave having a frequency lower than that of the carrier wave as identification information (ID information) for identifying that the carrier wave has a high frequency such as 40 kHz as its own transmission signal. Create a signal.

FIG. 3 is a diagram showing an example of creating a transmission signal.
FIG. 3 is a diagram showing an example of a transmission signal when the carrier wave is 40 kHz and the signal wave for ID information is 20 kHz. The transmission signal shown in FIG. 3 is a signal in which transmission and stop of a 40 kHz signal are repeated for the same time. That is, the transmission signal shown in FIG. 3 is a signal having a wavelength of 40 kHz and a wave of 20 kHz per second.

The signal transmission unit 13 supplies a signal for the ultrasonic sensor 11 to output a transmission signal (sound wave signal) to the ultrasonic sensor 11. The signal transmission unit 13 is composed of, for example, an amplifier and a DA conversion circuit. The signal transmission unit 13 inputs a signal based on the signal information for transmission created by the signal creation unit 12 to the ultrasonic sensor 11 at a preset cycle. As a result, the signal transmission unit 13 controls to output the transmission signal from the ultrasonic sensor 11 at a predetermined cycle.

The signal receiving unit 14 acquires a received signal. The signal receiving unit 14 is composed of, for example, an amplifier, an AD conversion circuit, and the like. The signal receiving unit 14 acquires the signal converted by the ultrasonic sensor 11 as a digital signal. The signal receiving unit 14 sends the acquired signal to the filter processing unit 15.

The filter processing unit 15 extracts a frequency component from the received signal from the signal receiving unit 14. For example, the filtering unit 15 extracts the frequency component included in the received signal by using the Fourier transform. The following equation (Equation 1) shows a Fourier transform equation.

The filter processing unit 15 may calculate only the Fourier coefficient of a specific order in order to reduce the amount of calculation.

The signal determination unit 16 determines whether or not the received signal is its own transmission signal by using the Fourier coefficient calculated by the filter processing unit 15. For example, the signal determination unit 16 determines whether or not the frequency component of the transmission signal is included in the reception signal. In this case, the signal determination unit 16 determines that the received signal is its own transmission signal if the frequency component of the transmission signal is included in the reception signal, and receives if the frequency component of the transmission signal is not included in the reception signal. It is determined that the signal is not its own transmission signal.

When the signal determination unit 16 determines that the received signal is its own transmission signal, the distance measurement unit 17 performs distance measurement processing for determining the distance to an object (an object that reflects the transmission signal). The distance measuring unit 17 determines the distance to the object from the time difference between the transmission timing of the transmission signal and the reception timing of the reception signal.

The communication unit 18 is a communication interface for communicating with the robot 2. For example, the communication unit 18 transmits distance measurement information indicating the distance to the object determined by the distance measurement unit 17 to the robot 2. The communication unit 18 may perform wired communication, or may perform wireless communication. For example, the communication unit 18 may perform wireless communication such as wide area communication such as Wi-Fi (registered trademark), Bluetooth (registered trademark), and UWB (Ultra Wide Band) as wireless communication. Further, the communication unit 18 may include an interface for wired communication and an interface for wireless communication.

The display unit 19 displays distance measurement information, information indicating an operating state of the sensor terminal 1, and the like. The display unit 19 may be a display that displays character information, an image, or the like, or an LED (Light Emitting) that indicates in a display state such as blinking that distance measurement has been performed to confirm the operation of the sensor terminal 1. It may be a lamp such as Diode). The display unit 19 is an example of a notification unit for notifying information. The sensor terminal 1 may be provided with a speaker or the like that outputs information by voice as a notification unit.

Next, the processing of the sensor terminal 1 according to the first embodiment will be described.
FIG. 4 is a flowchart for explaining a processing example of the sensor terminal 1.
In the sensor terminal 1, the processor 21 creates signal information for transmission in which the carrier wave of the signal output by the ultrasonic sensor 11 is modulated by its own identification information (ID information) by the signal creation unit 12 (ST11). For example, as shown in FIG. 3, the signal creation unit 12 creates signal information for transmission that modulates the carrier wave output by the ultrasonic sensor 11 with a signal wave having a frequency lower than that of the carrier wave as its own identification information.

When the signal information for transmission is created, the processor 21 supplies the signal information for transmission from the signal creation unit 12 to the signal transmission unit 13 at a predetermined timing. As a result, the signal transmission unit 13 causes the ultrasonic sensor 11 to output a transmission signal (sound wave) based on the signal information for transmission from the signal creation unit 12 (ST12).

After transmitting the transmission signal from the ultrasonic sensor 11, the processor 21 waits for the reception of the sound wave as the reception signal (ST13). In the reception waiting state, the processor 21 determines whether or not the signal has been received by the ultrasonic sensor 11 and the signal receiving unit 14 (ST14). The signal transmission unit 13 may periodically output a transmission signal (sound wave), and ST12 and ST13 may be executed in parallel.

In the reception waiting state, the ultrasonic sensor 11 as a sensor for reception converts the received sound wave into an electric signal. The signal receiving unit 14 acquires an electric signal from the ultrasonic sensor 11 as a received signal. The processor 21 acquires a received signal from the signal receiving unit 14, and analyzes the frequency component of the received signal by the filtering unit 15 (ST15). The processor 21 determines whether or not the frequency component of the received signal and the frequency component of the transmitted signal match by the signal determination unit 16 based on the analysis result of the frequency component of the received signal by the filter processing unit 15 (ST16). ..

When the frequency component of the received signal and the frequency component of the transmitted signal match (ST16, YES), the processor 21 executes the distance measurement by the distance measuring unit 17 (ST17). For example, the processor 21 measures the time difference from the timing when the transmission signal is output to the timing when the reception signal is received by the stop watch function or the like in order to measure the distance by the distance measuring unit 17. The distance measuring unit 17 calculates the distance to the object from the transmission timing of the transmission signal and the reception timing of the reception signal. When the distance measuring unit 17 calculates the distance to the object, the processor 21 transmits the distance measuring information indicating the distance of the object to the robot 2 by the communication unit 18 (ST18). Further, the processor 21 may display information indicating the distance calculated by the distance measuring unit 17 on the display unit 19. Further, the processor 21 may display information indicating that the distance has been calculated by the distance measuring unit 17 on the display unit 19.

As described above, the sensor terminal according to the first embodiment is provided with a distance measuring unit using ultrasonic waves, has a function of adding its own identification information to the output ultrasonic signal and transmitting it, and is it its own signal at the time of reception? It has a function to determine. The sensor terminal creates a transmission signal by pulse width modulation so that the high-frequency carrier wave contains low-frequency signal wave information indicating identification information. Further, the sensor terminal extracts signal wave information from the received signal and determines whether it is a signal output by itself. The sensor terminal performs distance measurement when the received signal is a signal output by itself.

That is, according to the first embodiment, when the sensor terminal outputs a transmission signal in which a carrier wave is modulated by a signal wave as identification information, and then the frequency component of the received reception signal matches the frequency component of the transmission signal. , The distance to the object is calculated from the transmission timing of the transmission signal and the reception timing of the reception signal.

As a result, the sensor terminal according to the first embodiment can measure the distance to the object when it receives a reception signal whose frequency component matches its own transmission signal. As a result, according to the sensor terminal of the first embodiment, it is possible to suppress erroneous determination due to a transmission signal output from a device other than itself or external noise such as vibration sound of a machine, and a large number of sensor terminals can be used. Reliable distance measurement can be realized even in an existing area.

Further, according to the first embodiment, there is an advantage that the signal can be determined even in a microphone having a narrow receivable frequency band by pulse width modulation. In addition, there is an advantage that a large amount of ID information can be identified even in a general microphone used in a smartphone or the like, which cannot accurately receive ultrasonic waves having a sampling frequency of 45 kHz or less.

Further, the sensor terminal according to the first embodiment ultrasonically transmits a signal creation unit that creates signal information for transmission including unique identification information and a transmission signal based on the signal information for transmission created by the signal creation unit. A signal transmission unit to be output from a sensor, a signal reception unit to acquire a sound signal input by the ultrasonic sensor as a reception signal, a filter processing unit to analyze the frequency component of the reception signal, and a frequency component of the reception signal A signal determination unit that determines whether or not it matches the frequency component of the transmission signal, a distance measuring unit that determines the transmission timing of the transmission signal and the distance from the reception timing of the reception signal to the object, and the distance measurement unit. It is provided with a communication unit that transmits the distance measurement result by the above to an external device.
With these configurations, the sensor terminal according to the first embodiment can determine whether or not the received signal is a signal transmitted by itself, and performs distance measurement by accurately associating the transmitted signal with the received signal. This makes it possible to suppress erroneous determination and perform accurate distance measurement.

Further, the sensor terminal according to the first embodiment may include a display unit for displaying distance-measured information and the like, and may display the distance-measured information and ID information on the display unit. As a result, it is possible to easily verify the convenience of the user and the validity of the distance measurement.

(Second Embodiment)
Next, the second embodiment will be described.
In the system according to the second embodiment, the sensor terminal 101 is installed on a moving body, and the sensor terminal 101A receives an ultrasonic signal output from a signal transmitting device 102 installed at a predetermined position. That is, the system according to the second embodiment is a device in which the signal transmission device 102 transmits an ultrasonic signal, and the sensor terminal 101 is a device for receiving an ultrasonic signal output from the signal transmission device 102. 1 Different from the embodiment.

FIG. 5 is a diagram schematically showing a configuration example of an industrial system including the sensor terminal 101 and the signal transmission device 102 according to the second embodiment.
In the configuration example shown in FIG. 5, the industrial system according to the second embodiment includes a sensor terminal 101A installed on the robot 201A, a sensor terminal 101B carried by the worker P, and a signal transmission device 102A installed at a predetermined position. , 102B.

The sensor terminal 101A is installed on a robot 201A or the like used for transporting articles or assembling products. In the robot 201A, at least the part where the sensor terminal 101 is installed moves. For example, the robot 201A may be an automatic guided vehicle (AGV), a robot arm in which the tip of the arm moves, or the like.

The sensor terminal 101B is carried by a worker P who moves in the workplace. The sensor terminal 101B has a function of communicating with the mobile terminal 201B possessed by the worker P. The sensor terminal 101B notifies the mobile terminal 201B of the detected information and the like. Further, the function of the sensor terminal 101B may be built into the mobile terminal 201B.
The sensor terminal 101A and the sensor terminal 101B will be described as a device (sensor terminal 101) having the same configuration.

The signal transmission device 102 (102A, 102B) is installed at a predetermined position, respectively. For example, the signal transmission device 102 is fixedly installed at a predetermined position such as a ceiling. The signal transmission device 102 radiates a transmission signal including its own ID information to a preset radiation position (region). It is assumed that there are a plurality of signal transmission devices 102 as a whole system. For example, in a predetermined area such as a factory or a workplace, a large number of signal transmission devices are arranged at predetermined positions.

Next, the configuration of the sensor terminal 101 according to the second embodiment will be described.
The sensor terminal 101 according to the second embodiment has a function of receiving a sound wave signal output from the signal transmission device 102.
FIG. 6 is a block diagram showing a configuration example of the sensor terminal 101 according to the second embodiment.
The sensor terminal 101 includes an ultrasonic sensor (ultrasonic sensor for reception) 111, a signal receiving unit 114, a filter processing unit 115, a signal identification unit 116, a position determination unit 117, a communication unit 118, a display unit 119, a position DB 120, and the like. Have.

In the configuration example shown in FIG. 6, the filter processing unit 115, the signal identification unit 116, and the position determination unit 117 are functions realized by the processor 121 executing a program. That is, the filter processing unit 15, the signal identification unit 116, and the position determination unit 117 are configured as a processing device having a processor 121, a memory, and the like. However, the filter processing unit 115, the signal identification unit 116, and the position determination unit 117 may be realized by different hardware.

The ultrasonic sensor 111 is a receiving ultrasonic sensor that receives sound waves. The ultrasonic sensor 111 converts vibration (sound wave) in the air into an electric potential.

The signal receiving unit 114 acquires the signal converted by the ultrasonic sensor 111. The signal receiving unit 114 is composed of, for example, an amplifier, an AD conversion circuit, or the like. The signal receiving unit 114 acquires the signal converted by the ultrasonic sensor 111 as a digital signal. The signal receiving unit 114 sends the acquired signal to the filter processing unit 115.

The filter processing unit 115 extracts a frequency component from the received signal from the signal receiving unit 14. For example, the filter processing unit 115 extracts the frequency component included in the received signal by using the Fourier transform described in the first embodiment. The filter processing unit 115 may calculate only the Fourier coefficient of a specific order in order to reduce the amount of calculation.

The signal identification unit 116 identifies the identification information (ID information) included in the received signal based on the analysis result of the frequency component for the received signal by the filter processing unit 115. For example, the signal identification unit 116 identifies the ID information included in the received signal by using the Fourier coefficient calculated by the filter processing unit 115.

The position determination unit 117 identifies its own position based on the ID information. The position DB 120 stores the position information in association with the ID information. The position DB 120 may be a memory that is communicatively connected to the processor 121, or may be a memory included in the processor 121. The position DB 120 stores, for example, position information indicating the position of the signal transmission device 102 corresponding to the ID information. The position determination unit 117 identifies its own position by referring to the position DB 120 based on the ID information specified by the signal identification unit 116. The position determination unit 117 specifies, for example, the signal transmission device 102 corresponding to the ID information, and specifies its own position from the position of the signal transmission device 102.

The processor 121 of the sensor terminal 101 may transmit the ID information identified by the signal identification unit 116 to the robot 201A or the mobile terminal 201B instead of the position information indicating its own position. The robot 201A or the mobile terminal 201B may acquire the ID information identified by the signal identification unit 116 from the sensor terminal 101 and grasp its own position based on the acquired ID information. Further, when the sensor terminal 101 outputs the ID information identified by the signal identification unit 116, the position determination unit 117 and the position DB 120 may be omitted.

The communication unit 118 is an interface for outputting the processing result of the sensor terminal 101 to an external device. For example, the communication unit 118 is a communication interface for communicating with the robot 201A or the mobile terminal 201B. The communication unit 118 transmits the position information based on the ID information identified by the signal identification unit 116 to the robot 201. Further, the communication unit 118 may transmit the ID information identified by the signal identification unit 116 to the robot 201A or the mobile terminal 201B. The communication unit 118 may transmit information by wire, or may transmit information by wireless communication such as Wi-Fi, Bluetooth, or UWB. Further, the communication unit 118 may include an interface for wired communication and an interface for wireless communication.

The display unit 119 displays information such as the identified ID information, the position information specified from the ID information, or the information indicating the state of the sensor terminal 101. The display unit 119 may be a display that displays character information or an image, or is a lamp such as an LED that indicates in a display state such as blinking that identification of ID information has been performed for operation confirmation. You may. The display unit 119 is an example of a notification unit for notifying information. The sensor terminal 101 may be provided with a speaker or the like that outputs information by voice as a notification unit.

Next, the configuration of the signal transmission device 102 according to the second embodiment will be described.
The signal transmission device 102 according to the second embodiment has a function of transmitting a signal by sound waves that can be received by the sensor terminal 101.
FIG. 7 is a block diagram showing a configuration example of the signal transmission device 102 according to the second embodiment.
The signal transmission device 102 includes a signal creation unit 211, a signal transmission unit 212, an ultrasonic sensor (ultrasonic sensor for transmission) 213, and the like.

In the configuration example shown in FIG. 7, the signal creation unit 211 is a function realized by the processor executing a program. That is, the signal creation unit 211 is configured as a processing device having a processor, a memory, and the like. However, the signal creation unit 211 may be realized by hardware.

The ultrasonic sensor 213 is a transmission ultrasonic sensor that transmits sound waves. The ultrasonic sensor 213 vibrates in response to a transmission signal input from the signal transmission unit 212, and outputs a sound wave as a transmission signal.

The signal creation unit 211 creates signal information for transmission to be supplied to the signal transmission unit 212 as a transmission signal output by the ultrasonic sensor 213. The signal creation unit 211 creates a signal including information of a signal wave having a frequency lower than that of the carrier wave as its own identification information (ID information) for a carrier wave having a high frequency such as 40 kHz.

The signal transmission unit 212 supplies the transmission signal to the ultrasonic sensor 213. The signal transmission unit 212 is composed of, for example, an amplifier and a DA conversion circuit. The signal transmission unit 212 inputs the transmission signal based on the communication signal information created by the signal creation unit 211 to the ultrasonic sensor 213 at a preset cycle. As a result, the signal transmission unit 212 controls to output the transmission signal from the ultrasonic sensor 213 at a predetermined cycle.

Next, an operation example of the sensor terminal 101 and the signal transmission device 102 according to the second embodiment will be described.
First, the operation of the signal transmission device 102 according to the second embodiment will be described.
FIG. 8 is a flowchart for explaining a processing example of the signal transmission device 102 according to the second embodiment.
In the signal transmission device 102, the processor 221 creates signal information for transmission in which the carrier wave of the signal output by the ultrasonic sensor 11 is modulated by its own identification information (ID information) by the signal creation unit 211 (ST21). For example, the signal creation unit 211 creates signal information for transmission in which the carrier wave output by the ultrasonic sensor 11 is modulated by a signal indicating its own identification information (ID information).

When the signal information for transmission is created, the processor 221 supplies the signal information for transmission from the signal creation unit 211 to the signal transmission unit 212 at a predetermined timing. As a result, the signal transmission unit 212 outputs a transmission signal based on the signal information for transmission from the signal creation unit 211 from the ultrasonic sensor 213 (ST22).

Next, the operation of the sensor terminal 101 according to the second embodiment will be described.
FIG. 9 is a flowchart for explaining a processing example of the sensor terminal 101 according to the second embodiment.
In the sensor terminal 101, the processor 121 is put into a state of waiting for signal reception by the ultrasonic sensor 111 and the signal receiving unit 114 (ST31).

In the reception waiting state, the ultrasonic sensor 111 as a sensor for reception converts the received sound wave into an electric signal. The signal receiving unit 114 acquires an electric signal from the ultrasonic sensor 111 as a received signal. The processor 121 acquires the signal received by the ultrasonic sensor 111 as a received signal from the signal receiving unit 114 (ST32, YES), and analyzes the frequency component of the received signal by the filter processing unit 115 (ST33). The processor 121 identifies the ID information included in the received signal by the signal identification unit 116 based on the analysis result of the frequency component of the received signal by the filter processing unit 115 (ST34).

When the ID information is specified by the signal identification unit 116, the processor 121 specifies the position based on the ID information by the position determination unit 117 (S35). The position determination unit 117 identifies the signal transmission device 102 corresponding to the ID information extracted from the received signal by the signal identification unit 116 with reference to the position DB 120, and specifies its own position from the position of the specified signal transmission device 102. ..

When the position of the processor 121 is specified, the processor 121 transmits the position information indicating the position of the processor 121 to the robot 201A, the mobile terminal 201B owned by the person, or the like (ST36). The processor 121 may transmit the ID information to the robot 201A, the mobile terminal 201B possessed by a person, or the like by the communication unit 118.

Further, the processor 121 may display information such as ID information identified by the signal identification unit 116 or position information indicating a position specified by the position determination unit 117 on the display unit 19. Further, the processor 21 may display information indicating the operating state of the sensor terminal 101, such as the signal identification unit 116 identifying the ID information, on the display unit 19.

As described above, according to the second embodiment, the signal transmission device installed at a predetermined position outputs a transmission signal in which a carrier wave is modulated based on ID information. The sensor terminal extracts ID information from the received received signal, identifies the signal transmission device of the signal transmission source based on the extracted ID information, and specifies its own position from the position of the specified signal transmission device.

As a result, the sensor terminal according to the second embodiment can identify the signal transmission device of the signal transmission source by the ID information extracted from the received signal, and can calculate its own position from the position of the signal transmission device. As a result, even in the area where a large number of signal transmission devices are arranged, each sensor terminal can reliably identify its own position by the signal from each signal transmission device.

The system according to the second embodiment includes a sensor terminal mounted on a robot or a person, and a signal transmission device for transmitting a signal including its own ID information. The sensor terminal has a signal receiving unit that acquires a sound wave signal input by a receiving ultrasonic sensor as a receiving signal, a filter processing unit that analyzes a frequency component of the received signal, and ID information included in the received signal. It includes a signal identification unit for identification and a communication unit for transmitting the identification result of ID information by the signal identification unit to an external device. The signal transmission device includes a signal creation unit that creates signal information for transmission including its own ID information, and an ultrasonic sensor for transmitting a transmission signal based on the signal information for transmission created by the signal creation unit. It is provided with a signal transmission unit to be transmitted from.
With these configurations, according to the sensor terminal according to the second embodiment, it is possible to identify its own position based on the ID information identified from the received received signal.

Further, the sensor terminal according to the second embodiment may include a display unit that displays information such as the identified ID information or the position based on the ID information. The sensor terminal according to the second embodiment can easily verify the convenience of the user and the validity of the position by displaying the identified ID information or the position on the display unit.

(First modification)
Next, a first modification applicable to the first embodiment and the second embodiment will be described. The first modification is a modification applicable to the signal creating units 12 and 211 described in the first embodiment and the second embodiment. Further, in the second embodiment, the signal identification unit 116 identifies the ID information from the received signal by processing according to the method applied to the signal creation unit 112.

10 and 11 are diagrams for explaining a method of creating a transmission signal including ID information as a first modification. FIG. 10 shows an example of a transmission signal when the ID information is “1”. FIG. 11 shows an example of a transmission signal when the ID information is “2”.
In the first modification, in order to express the ID information in the transmission signal, the frequency of the signal wave is changed in time series according to the ID information. The signal creation units 12 and 211 create signal information for transmission indicating the ID information by changing the frequency of the signal wave in a time series in a pattern associated with the ID information. In response to this, the signal identification unit 116 identifies the ID information by the pattern of the frequency change in the received signal.

10 and 11 show an example of a transmission signal when, for example, three kinds of frequencies (5 kHz, 10 kHz, and 20 kHz) are used as signal waves. FIG. 10 is an example of a transmission signal when the ID information is “1”. In the example shown in FIG. 10, the frequency change pattern is in the order of 20 kHz, 10 kHz, and 5 kHz in association with "1" of the ID information. Further, in the example shown in FIG. 11, the frequency change pattern is set in the order of 20 kHz, 10 kHz, and 5 kHz in association with the ID information “2”. By changing the frequency according to the ID information as described above, it is possible to create a transmission signal indicating a plurality of ID information.

According to the first modification, a plurality of ID information can be expressed in the transmission signal by using the frequency change pattern as compared with the case where the ID information is expressed only by the frequency as shown in FIG. That is, according to the first modification, a large number of ID information assigned to each of a large number of signal transmission devices can be displayed by using a frequency change pattern, and is included in the signals output from each signal transmission device. By specifying the frequency change pattern, the ID information given to a large number of signal transmission devices can be reliably identified.

Further, according to the first modification, in the sensor terminal according to the first embodiment or the second embodiment, the number of identifiable ID information is increased by switching the frequency of the signal wave in the transmission signal in chronological order. Is possible.

(Second modification)
Next, a second modification applicable to the first embodiment and the second embodiment will be described. The second modification is a modification applicable to the signal creating units 12 and 211 described in the first embodiment and the second embodiment. Further, in the second embodiment, the signal identification unit 116 identifies the ID information from the received signal by processing according to the method applied to the signal creation unit 112.

12 and 13 are diagrams for explaining a method of creating a transmission signal including ID information as a second modification. FIG. 12 shows an example of a transmission signal output by the second modification when the ID information is “1”. FIG. 13 shows an example of a transmission signal output by the second modification when the ID information is “5”.
In the second modification, the interval (1 slot) for transmitting ID information is defined in the transmission signal, and the ID information is expressed by the signal length in 1 slot. That is, in the second modification, the signal creation units 12 and 211 create signal information for transmission in which the signal length in one slot is the length corresponding to the ID information. In response to this, the signal identification unit 116 identifies the ID information according to the signal length in one slot of the received signal.

Here, with reference to FIGS. 12 and 13, an example of a transmission signal in which one slot is 100 ms and ID information “1” to “10” is represented by a signal length of every 10 ms will be described. In this case, the signal creation units 12 and 211 create signal information for transmission so that the signal length in one slot satisfies the following equation (2).
ID information number = received signal length [ms] / 10 [ms] ... (2).

For example, when the ID information is "1", the signal creation units 12 and 211 create signal information for transmission which is a transmission signal for outputting a signal having a signal length of 10 ms at 100 ms intervals, as shown in FIG. .. When the ID information is "5", the signal creation units 12 and 211 create signal information for transmission, which is a transmission signal that outputs a signal having a signal length of 50 ms at 100 ms intervals, as shown in FIG. .. Corresponding to these, the signal identification unit 116 identifies the ID information by specifying the signal length in one slot of the received signal.

As described above, according to the second modification, by expressing the ID information by the signal length in a predetermined interval (1 slot), a large number of ID information can be expressed even at a single frequency, and a large number of ID information can be expressed. It is possible to realize an operation mode that identifies the ID information of the signal transmission device of.

Further, when the transmission signal having the configuration described in the second modification is output, the sensor terminals 1 and 101 can determine whether or not the received signal can be normally received.
14 and 15 are for explaining a process of determining whether or not a transmission signal indicating ID information can be normally received at a signal length of a predetermined interval (1 slot) as shown in FIG. 12 or 13. It is a figure.

Whether or not the processors 21 and 121 have normally received the signal based on the interval between the timing when the signal reception is started (the timing when the signal is turned on) and the interval when the signal reception is finished (the timing when the signal is turned off). May be determined. For example, when the signal identification unit 116 identifies the ID information, the interval of the timing when the signal reception is started (the timing when the signal is turned on) and the interval when the signal reception is finished (the timing when the signal is turned off) are set respectively. It may be recorded and determined whether to identify the received signal.

Since the signal length according to the ID information is output for each fixed slot, if the signal can be received normally, the length of one slot, the interval of the timing to turn on, and the interval of the timing to turn off 3 One matches. If the signal cannot be received accurately due to a shield or the like, the length of the received signal changes, so that the length of one slot, the interval of ON timing, and the interval of OFF timing do not match. ..

FIG. 14 is a diagram for explaining a case where the signal can be normally received, and FIG. 15 is a diagram for explaining a case where the signal cannot be normally received. If the signal can be received normally, as shown in FIG. 14, the interval of the timing of turning on and the interval of the timing of turning off correspond to the length of one slot. Further, when the signal is not normally received, as shown in FIG. 15, the interval of the timing of turning on or the interval of the timing of turning off does not match the length of one slot.

As described above, when the ID information is expressed by the signal length in a predetermined interval (1 slot) in the transmission signal as in the second modification, the interval at which the signal is turned on and the timing at which the signal is turned off are determined. Whether or not the signal can be normally received can be determined by whether or not the interval matches the length of one slot. This makes it possible to suppress erroneous identification of ID information due to signal loss due to noise or a shield or the like.

Further, according to the second modification, in the sensor terminal according to the first embodiment or the second embodiment, the ID information can be identified from the signal length by setting the output signal length to a unique value for each ID. Become.
Further, according to the second modification, in the received signal, the interval of the timing to turn on and the interval of the timing to turn off are measured, and when each interval matches the transmission interval of the signal, the reception is regarded as a normal signal. Identify the ID information contained in the signal. As a result, it is possible to suppress erroneous determination due to a received signal lacking some information.

(Third modification example)
Next, a third modification applicable to the first embodiment and the second embodiment will be described. The third modification is a modification applicable to the signal creating units 12 and 211 described in the first embodiment and the second embodiment. Further, in the second embodiment, the signal identification unit 116 identifies the ID information from the received signal by processing according to the method applied to the signal creation unit 211.

16 and 17 are diagrams for explaining a method of generating a transmission signal including ID information as a third modification.
In the third modification, as shown in FIGS. 16 and 17, ID information is expressed by dividing one slot in the transmission signal into finer time intervals (1 block) and turning the signal on or off for each block. It is a thing. The signal identification unit 116 identifies the ID information shown in the transmission signal by determining whether or not the signal exists in each block in one slot of the transmission signal.

For example, if one slot is 100 ms and one block is 10 ms, a start signal of 50 ms is transmitted at the beginning of one slot to notify the start of signal reception, and then the ID is expressed in binary notation of on and off for five blocks. Can express information. In the example shown in FIG. 16, 5 blocks serving as a start signal are turned on in one slot, and 5 blocks after the start signal are set to "off", "off", "off", "off", and "on", respectively. "00001" is expressed as a binary number of digits. Further, in the example shown in FIG. 17, 5 blocks serving as a start signal are turned on in one slot of the transmission signal, and 5 blocks after the start signal are set as "off", "off", "on", "off", and "on", respectively. By doing so, "00101" is expressed as a 5-digit binary number.

Further, when the ID information is expressed by dividing it into a plurality of blocks, information other than the ID information may be added to the transmission signal. For example, in order to suppress erroneous determination, information for error correction of the received signal may be added.
As described above, according to the third modification, by expressing the ID information by the presence / absence of signals in the plurality of blocks provided in the transmission signal, it is possible to express a large number of ID information, and further, the ID information. It is also possible to add information other than.

Further, according to the third modification, the ID information is expressed by switching the transmission signal on and off at fixed times defined as individual blocks in the transmission signal. As a result, a large amount of ID information can be expressed in the on / off state of each block at a fixed time in the transmission signal.

(Fourth modification)
Next, a fourth modification applicable to the first embodiment and the second embodiment will be described. The fourth modification is a modification applicable to the signal creating units 12 and 211 described in the first embodiment and the second embodiment. Further, in the second embodiment, the signal identification unit 116 identifies the ID information from the received signal by the process according to the method applied to the signal creation unit 211.

18 to 20 are diagrams for explaining a method of generating a transmission signal including ID information as a fourth modification.
In the fourth modification, the ID information is expressed by switching the frequency of the signal wave and changing the length of the signal in the transmitted signal. For example, the transmission signal may represent the tens digit of the ID number as ID information by the frequency of the signal wave, and may represent the ones digit of the ID number by the length of the signal length.

For example, in the examples shown in FIGS. 18 to 20, in the case of 10 kHz, the ID number is in the 10s, and in the case of 20 kHz, the ID number is in the 20s. FIG. 18 is an example of a transmission signal expressing the ID number “11” by setting the frequency of the signal wave to 10 kHz and the signal length to 10 ms. Further, FIG. 19 shows a transmission signal having a signal wave frequency of 10 kHz and a signal length of 20 ms in order to express that the ID number is “12”. Further, FIG. 20 is an example of a transmission signal expressing the ID number “21” by setting the frequency of the signal wave to 20 kHz and the signal length to 10 ms.

The signal creation unit 211 may speed up the transmission interval of the signal (sound wave) to 20 ms or less by limiting the signal length in the signal information for transmission to be created to 1 ms or less. By shortening the signal transmission interval, even when the moving speed of a moving object such as a robot or a person equipped with a sensor terminal is high, the time resolution of distance estimation with a peripheral detection object can be improved.
As described above, according to the fourth modification, a large amount of ID information is expressed by expressing the ID information by using the change in the frequency of the signal wave and the change in the length of the signal in combination in the transmission signal. It becomes possible.

The sensor terminal according to the fourth modification identifies the ID information from the frequency information and the signal length of the signal wave in the received signal. As a result, according to the fourth modification, the ID information can be expressed by the frequency information and the signal length of the signal wave in the ultrasonic signal, and a large amount of ID information can be expressed.

Further, according to the fourth modification, the time resolution of the distance estimation can be improved by limiting the signal length of the transmission signal to the set value or less, and the signal can be reliably received even when the object is close or moving at high speed. ID information included in the signal can be specified.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1 (1A, 1B) ... Sensor terminal, 11 ... Ultrasonic sensor, 12, 112 ... Signal creation unit, 13 ... Signal transmission unit, 14, 114 ... Signal reception unit, 15, 115 ... Filter processing unit, 16, 116 ... Signal determination unit, 17, 117 ... Distance measuring unit, 18, 118 ... Communication unit, 19, 119 ... Display unit, 21, 121 ... Processor, 101 (101A, 101B) ... Sensor terminal, 111 ... Ultrasonic sensor (for reception) Ultrasonic sensor).

Claims (11)

A signal receiving unit that acquires a received signal obtained by converting the sound wave received by the ultrasonic sensor into an electric signal,
A processor that analyzes the frequency component of the received signal acquired by the signal receiving unit and identifies the identification information included in the received signal based on the analysis result of the frequency component of the received signal.
A sensor terminal comprising. The processor
Create transmission signal information to output a transmission signal including identification information unique to the sensor terminal.
After the ultrasonic sensor outputs a transmission signal corresponding to the signal information for transmission, the transmission of the transmission signal is transmitted when the frequency component of the reception signal acquired by the signal receiving unit matches the frequency component of the transmission signal. The distance to the object is calculated based on the timing and the reception timing of the received signal.
The sensor terminal according to claim 1. The identification information included in the received signal is identification information indicating the source of the received signal.
The processor identifies the transmission source by the identification information included in the received signal based on the analysis result of the frequency component of the received signal.
The sensor terminal according to claim 1. The processor identifies the position of the sensor terminal based on the position of the source identified by the identification information contained in the received signal.
The sensor terminal according to claim 3. The processor identifies the identification information based on the time-series changes in the frequency of the signal wave in the received signal.
The sensor terminal according to any one of claims 1 to 4. The processor identifies the identification information based on the signal length in the received signal.
The sensor terminal according to any one of claims 1 to 4. The processor executes the identification of the identification information when the interval at which the signal is turned on and the interval at which the signal is turned off in the received signal coincides with the transmission interval of the signal.
The sensor terminal according to claim 6. The processor identifies identification information based on the on or off state of the signal at predetermined fixed time intervals in the received signal.
The sensor terminal according to any one of claims 1 to 4. The processor identifies the identification information based on the frequency and signal length of the signal wave in the received signal.
The sensor terminal according to any one of claims 1 to 4. The signal length of the received signal is limited to a predetermined set value or less.
The sensor terminal according to any one of claims 1 to 9. Further, it has a notification unit that notifies information about the identification information specified by the processor.
The sensor terminal according to any one of claims 1 to 10.