JP5998336B2 - Space monitoring apparatus and space monitoring method - Google Patents

Description

  The present invention relates to a space monitoring device and a space monitoring method.

  There is a need to monitor the state of a space such as a living room for the purpose of watching elderly people living alone, infants, pets, and the like. As a method to meet the needs, a method in which a video camera is always operated, a passing type optical sensor, an infrared sensor, an ultrasonic sensor, etc. is installed and an operation in a space is detected and used. Yes.

  However, monitoring with a video camera may not be preferable from the viewpoint of the privacy of the watching target. In addition, the pass-through sensor has a problem that it is necessary to arrange a large number of sensors because the behavior cannot be detected unless it is on the axis of the sensor. Sensors using infrared radiation (pyroelectric sensors) may malfunction due to disturbances such as vibration or electromagnetic waves, and if there are pets such as dogs and cats that have similar temperatures to human body temperature Cannot be identified as an action. Furthermore, in the case of a motion sensor using ultrasonic waves, the directivity of the sensor is strong, and even if it is slightly out of the detection area, it may not be detected, so the installation location needs attention and covers the target space For this purpose, there has been a problem that a large number of sensors are required.

  On the other hand, for example, the technique of Patent Document 1 has been proposed. Patent Document 1 is an apparatus that monitors the intrusion of an object into a monitoring space using wireless technology, and installs a UWB transmitter and a UWB receiver that perform transmission / reception in the OMDF system at a fixed position in a room to be monitored, It has a configuration for detecting an abnormality such as opening of an entrance / exit door and breakage of a glass window based on a change with respect to a reference reception intensity.

JP 2009-80767 A

  However, in the apparatus of Patent Document 1, it is necessary to prepare a transmitter and a receiver in pairs because of the configuration, which increases the installation cost. Since the transmitter tends to malfunction when the level or phase on the transmission side changes, the sensitivity of the receiver. Because of the problem of not being able to raise the temperature sufficiently, it could not be said to be sufficient as a device for space monitoring.

  The present invention has been made to solve the above-described problems, and one object thereof is a space monitoring device and a space monitoring capable of accurately detecting a change in a situation such as a living room with a simple configuration. Is to provide a method.

  In order to solve the above problems and other problems, according to one aspect of the present invention, there is provided a space monitoring device for monitoring a space situation, and transmitting a high-frequency radio frequency signal to a space to be monitored. Transmitting as a wave and receiving the reflected wave, converting the transmitted wave and the reflected wave into digital data to obtain transmitted wave data and reflected wave data, comparing the transmitted wave data and the reflected wave data, A space monitoring device having a transmission / reception unit for detecting a difference in digital data is provided.

  According to one embodiment of the present invention, it is possible to accurately detect a change in a situation such as a living room with a simple configuration.

It is explanatory drawing of the space monitoring method by 1 aspect of this invention. It is explanatory drawing of the space monitoring method by 1 aspect of this invention. It is explanatory drawing of the space monitoring method by 1 aspect of this invention. It is explanatory drawing of the space monitoring method by 1 aspect of this invention. It is a figure which shows the structural example of the space monitoring apparatus 1 by 1 aspect of this invention. 2 is a diagram illustrating a configuration example of a transmission / reception unit 10 of the space monitoring device 1. FIG. It is a figure which shows an example of the space monitoring process flow by the space monitoring apparatus. 7 is an explanatory diagram illustrating an application example of the space monitoring device 1. FIG.

  Hereinafter, the present invention will be described with reference to the accompanying drawings in accordance with the embodiment. First, a space monitoring method according to an embodiment of the present invention will be described with reference to FIGS. 1A to 1D. 1A to 1D are diagrams schematically illustrating the principle of the space monitoring method of the present embodiment. As shown in FIG. 1A, the space monitoring device 1 according to the present embodiment is installed in a substantially rectangular space R partitioned by walls or the like (assuming a general living room, the shape has no particular meaning). Suppose that The position of the device 1 is also an example and has no particular meaning. As will be described later, the space monitoring device 1 has a function of transmitting a radio frequency signal modulated by an arbitrary method into the space R as a transmission wave. At this time, it is assumed that the amplitude m and phase φ of the transmission wave are m0 and φ0, respectively. The transmitted wave is reflected by a wall surface in the space R and received by the space monitoring device 1 as a reflected wave. The amplitude and phase of the transmission wave are changed by reflection as is well known. The amplitude and phase of the reflected wave are m′0 and φ′0, respectively. Since it is assumed that there is no person or object in the space R in FIG. 1A, the amplitude and phase of the reflected wave measured by the space monitoring device 1 represent the radio characteristics of the space R. be able to.

  Next, referring to FIG. 1B, a situation in which there is one person P in the space R is shown. At this time, it is assumed that a transmission wave having an amplitude m0 and a phase φ0 is sent into the space R as in the case of FIG. 1A. In this case, the amplitude and phase of the reflected wave are reflected by the person P and transmitted through the person P as a dielectric, and thus have an amplitude m ″ 0 and a phase φ ″ 0 that are different from those in FIG. 1A. It is observed by the space monitoring device 1 as a reflected wave. The presence of the person P in the space R can be detected based on such changes in amplitude and phase.

  Next, FIG. 1C shows a situation where there is one person P in the space R as in FIG. 1B, but the position in the space R is different. At this time, the amplitude and phase of the reflected wave observed by the space monitoring device 1 with respect to the transmission wave having the amplitude m0 and the phase φ0 are different from those in FIG. 1B, for example, m ″ ′ 0 and φ ′ ″ 0. This is because, even if the person P is present in the space R, the aspect of reflection of the transmission wave changes due to the difference in position. This means that the information about the position of the dielectric material called the person P in the space R is also reflected in the amplitude and phase of the reflected wave. That is, the space monitoring device 1 can also detect the position of the person P in the space R. For example, information that the person P is near the telephone at the end of the space R can be obtained. .

  Next, referring to FIG. 1D, a situation where there is one dog D in the space R is shown. This situation is the same as the situation of FIG. 1B in that the living body exists in the space R, but the situation is different from the case of FIG. 1B in that there is a dog D instead of the person P as a dielectric. The aspect of the reflection of the transmitted wave is changing. This is because the difference in size of the dog D with respect to the person P and the difference in properties as a dielectric are reflected. That is, the type of living body existing in the space R can be detected by the space monitoring device 1.

  As described above, according to the space monitoring method of the present embodiment, the position and type of a living body existing in the space can be easily detected. In addition, by continuously transmitting transmission waves and observing reflected waves, the movement of an object in space can also be detected. Hereinafter, the configuration, function, and the like of the space monitoring device 1 that enables such a space monitoring method will be specifically described.

  First, the overall configuration of the space monitoring device 1 of the present embodiment will be described. FIG. 1 shows a configuration example of the space monitoring device 1. As shown in FIG. 1, the space monitoring device 1 of this embodiment includes a transmission / reception unit 10, a control unit 20, a communication interface unit (communication I / F unit) 30, a power supply unit 40, and an antenna 50.

  The transmission / reception unit 10 generates a transmission wave of a predetermined specification, and executes a process of receiving a reflected wave corresponding to the transmission wave and converting it into digital data. The transmission / reception unit 10 will be described later.

  The control unit 20 controls operations of the transmission / reception unit 10 and other functional units of the space monitoring device 1, and includes a calculation unit 21 and a storage unit 22. The computing unit 21 has a data processing device such as a CPU. The storage unit 22 includes a storage device such as a ROM or a RAM. The storage unit 22 can also include a storage device such as an HDD or an SSD. The storage unit 22 stores a program for realizing the functions of the space monitoring device 1, control data, and the like. The computing unit 21 controls the space monitoring device 1 by executing a program read from the storage unit 22.

  The communication I / F unit 30 is an interface for sending the analysis result by the control unit of the reflected wave waveform data acquired by the transmission / reception unit 10 to the communication network in order to transfer it to an external device, such as a network interface card (NIC). Consists of hardware. The power supply unit 40 is a unit for supplying power to each unit in the space monitoring device 1, and is configured by an appropriate power device that converts power supplied from a commercial power supply or the like not shown. The antenna 50 has a function of transmitting a transmission wave generated by the transmission / reception unit 10 to a space and receiving the reflected wave. In the spatial monitoring device 1 of the present embodiment, a radio frequency signal in the millimeter wave band (30 to 300 Ghz in frequency) is preferably used. Therefore, the antenna 50 is an antenna having a format suitable for transmitting and receiving such a radio frequency signal. Can be appropriately selected and used.

  Next, the transmission / reception unit 10 of the space monitoring device 1 in the present embodiment will be described. FIG. 3 shows a configuration example of the transmission / reception unit 10. As described above, the transmission / reception unit 10 has a function of generating and transmitting a transmission wave for space monitoring, receiving the reflected wave, and detecting a difference in characteristics from the transmission wave.

  The transmission / reception unit 10 transmits / receives a radio frequency signal based on a command from the control unit 20 as described later. When the transmission / reception unit 10 receives a transmission / reception processing start command from the control unit 20, the first oscillator 110 generates a transmission radio frequency signal having a predetermined frequency and waveform, and performs modulation processing by a predetermined method. The generated radio frequency signal is amplified by the amplifier 120 and input to the bridge circuit 130.

  The bridge circuit 130 has a function of separating the transmission wave from the amplifier 120 and the reflected wave from the antenna 50, and is configured as, for example, a directional coupler, a resistance bridge circuit, or the like. By the bridge circuit 130, the transmission wave is sent to the amplifier 141A and the reflected wave is sent to the amplifier 141B. The operation of the bridge circuit 130 is controlled by the control unit 20. The bridge circuit 130 configures a circuit from the amplifier 120 to the amplifier 141A at the timing of radio frequency signal transmission, and configures a circuit from the antenna terminal 190 to the amplifier 141B at the timing of reception of the reflected wave.

  The transmission wave amplified by the amplifier 141A is input to the frequency converter 142A. The frequency converter 142A has a function of converting the frequency of the transmission wave into an interface signal having a predetermined constant frequency, and can be configured as a mixer of various types. In the example of FIG. 3, the frequency converter 142A is an interface signal having the frequency of the sum, difference, or product of the transmission wave signal from the amplifier 141A and the conversion signal input from the second oscillator 150 via the amplifier 160. Is output to the amplifier 143A. The frequency converter 142A can always keep the frequency of the interface signal handled by the analog-to-digital (AD) converter 144A constant. In this embodiment, since the frequency of the interface signal (input signal to the AD converter 144A) can be made constant even if the frequency of the radio frequency signal is changed, the gain of the system itself is increased at the interface frequency after frequency conversion. Even if the sensitivity is increased, the change in circuit characteristics when the radio frequency signal frequency is changed can be reduced to a level that can be ignored.

  The output of the amplifier 143A is converted into a digital signal by the AD converter 144A and output to the digital signal processing circuit 170. The AD converter 144A can be configured by replacing a circuit such as a high-frequency detector for cost reduction. The reflected wave from the antenna terminal 190 is input from the bridge circuit 130 to the amplifier 141B, and after the same processing as that for the transmission wave is performed, it is input to the digital signal processing circuit 170 as a digital signal.

  The digital signal processing circuit 170 (signal analysis circuit) continuously converts the amplitude and phase of the digital signal as vector data corresponding to the transmission wave, and the amplitude and phase of the digital signal as vector data corresponding to the reflected wave, or Compared periodically, it has a function of detecting minute changes in the amplitude and phase of the reflected wave. The detected change in the reflected wave reflects the change in the state of the space in which the radio frequency signal is transmitted. The digital signal processing circuit 170 can be configured by, for example, a DSP, FPGA, CPU, or the like. The temperature sensor 180 detects the temperature at an appropriate place in the transmission / reception unit 10 and transmits it to the control unit 20 as temperature data. The temperature data received by the control unit 20 is used for temperature compensation of the circuit operation in the transmission / reception unit 10.

  According to the transmission wave / reflected wave processing in the transmission / reception unit 10 described above, the reflected wave is always observed using the radio frequency signal generated by the first oscillator 110 as a reference signal. It is possible to reduce the level drift due to the temperature and the change with time so that it can be ignored. Therefore, it is possible to detect the state of the space with higher accuracy.

  FIG. 4 shows a processing flow example of the space monitoring process executed by the control unit 20 of the space monitoring device 1. The space monitoring process is performed by executing a corresponding program that the calculation unit 21 of the control unit 20 reads from the storage unit 22. When starting the process in S500, the control unit 20 transmits a high-frequency radio frequency signal (transmission wave) from the transmission / reception unit 10 toward the target space. The frequency of the radio frequency signal is, for example, 30 to 300 GHz (millimeter wave band). Next, the control unit 20 causes the transmission / reception unit 10 to receive the reflected wave from the space (S520), and after converting it into an interface signal of a predetermined frequency by the interface circuit of the amplifier 141B to the amplifier 143B of FIG. 3 (S530), the AD converter The digital signal is converted by 144B (S540). Thereafter, the control unit 20 causes the digital signal processing circuit 170 to perform an analysis process of the reflected wave data and ends the process (S550, S560).

  A high-frequency radio frequency signal emitted from the space monitoring device 1 is reflected by a wall of the space, a person in the space, an object, etc., and returned as a reflected wave reflecting the state of the space, and is detected by the transmission / reception unit 10. Therefore, when a dielectric material such as a human body enters the target space during the transmission / reception operation and the propagation pattern of the radio wave in the space changes, a change appears in the amplitude and phase of the reflected signal. Similarly, the amplitude and phase change when the door in the space is opened and closed, and the door of a device such as a refrigerator is opened and closed. By capturing these changes, it is possible to infer situational changes such as movement of people in the space.

  In addition, for example, by dividing the monitoring target space into arbitrary meshes and creating a database of the characteristics of the reflected waves when there are people on each mesh, the approximate position of the person in the space can be determined by changes in the reflected waves. Can be detected. If the reflected wave pattern is accumulated even when the doors in the space are opened and closed, it is possible to roughly estimate the specific situation in the space.

  Note that the spatial monitoring device 1 of the present embodiment can also receive a radio frequency signal itself such as a mobile phone, a cordless phone, or a Wi-Fi signal by turning off the signal of the first oscillator 110. The presence or absence of these signals can also be detected, and when the user takes an action such as using a telephone, it can be recognized that the user is moving. It is possible to confirm whether or not the user is active by observing changes in the situation in these spaces at regular intervals. In addition, if it is observed that calls are received frequently despite being a single person, and that movements of users within the space are frequently detected accordingly, suspicious calls It is also possible to perform an operation such as notifying an alarm to a registered relative or the like regarding the user based on the assumption that it may correspond to the above.

  In addition, as described above, the conventional pyroelectric sensor has a problem that a pet such as a dog or a cat having a body temperature similar to that of a person moves and malfunctions. In the space monitoring apparatus 1 of the present embodiment, the frequency of the radio frequency signal for space monitoring is appropriately selected, and the signal is digitally processed to distinguish between a pet having a body temperature similar to that of a human and a human. It can be carried out. This is because there is a difference between the reflection of radio waves from humans and the reflection of radio waves from pets, such as that of humans.

  In the present embodiment, one space monitoring device 1 is installed in the monitoring target space. However, a plurality of space monitoring devices 1 may be provided depending on the space size and shape. In this case, by inserting an appropriate ID into the modulation signal of each device 1, each space monitoring device 1 can identify the radio frequency signal from each other.

Example Next, a specific application example of the space monitoring device 1 described in the above embodiment will be described as an example. In this embodiment, the space monitoring device 1 is applied to a toilet installed in a public place. FIG. 5 schematically illustrates a schematic configuration example of the toilet 600 according to the present embodiment.

  The toilet 600 is provided with a plurality of urinals 610, a plurality of urinals 620, a faucet for washing hands 630, and a dryer 640. A space monitoring device 1 is installed at an appropriate location in the toilet 600 to monitor the situation in the toilet 600. A computer 650 for managing the toilet 600 is installed at an arbitrary place.

  The space monitoring device 1 detects the presence and position of a person in the toilet 600 and the open / closed state of the door 615. Thereby, the usage status and congestion status of the toilet 600 can be displayed. Further, it is possible to estimate which toilet in the toilet 600 is in use by a reflected wave pattern analysis. Data from the space monitoring device 1 is transferred to the computer 650 through an appropriate communication line 660. Using this information, the computer 650 can provide the use status and congestion status of the toilet 600 in a state close to real time.

  The configuration of the present embodiment is effective for grasping not only the toilet but also a similar system such as a restaurant, a supermarket, an amusement park, and the like and the usage status.

  According to the embodiments of the present invention described above, changes in the state of a space such as the presence / absence of an object such as a person in a space such as a living room, movement status, opening / closing of a door or window, etc. can be detected with a simple configuration. can do.

  In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. In addition, a part of the configuration of the embodiment can be replaced with another configuration, and another configuration can be added to the configuration of a certain embodiment.

DESCRIPTION OF SYMBOLS 1 Space monitoring apparatus 10 Transmission / reception part 20 Control part 21 Calculation part 22 Storage part 30 Communication interface part 40 Power supply part 50 Antenna 110 1st oscillator 120,141A, 141B, 143A, 143B, 160 Amplifier 130 Bridge circuit 144A, 144B AD converter 150 Second Oscillator 180 Temperature Sensor 190 Antenna Terminal 650 Computer

Claims (3)

A space monitoring device for monitoring space information,
A signal in the frequency band of 30 to 300 GHz having a characteristic that the amplitude and phase change when reflected by an object existing in space is transmitted as a transmission wave to the space to be monitored, and the reflected wave is received. The reflected wave is converted into digital data to be transmitted wave data and reflected wave data.
By comparing the reflected wave data and the transmission wave data have a transceiver for detecting the differences in both the digital data,
The transceiver unit is
A transmitter that generates a radio frequency signal modulated in a predetermined manner;
A bridge circuit that separates the transmission wave of the radio frequency signal and the reflected wave from the space with respect to the transmission wave;
A frequency converter for converting the frequency of the transmitted wave and the reflected wave to a predetermined constant frequency;
An analog-to-digital converter that digitally converts the signal of the transmitted wave and the reflected wave converted to a constant frequency by the frequency converter ;
A signal analysis circuit for detecting the amplitude and phase of the transmission and the reflected wave from the digital data from the analog-digital converter, respectively, and detecting the amplitude and phase between the transmission wave and the reflected wave;
A space monitoring device. The space monitoring device according to claim 1,
By dividing the spatial object into arbitrary meshes and creating a database of reflected wave characteristics when there are people on each mesh,
Differences in digital data between transmitted wave data and reflected wave data corresponding to different situations in the space to be monitored are stored as a plurality of situation representative data, and the transmitted wave data and received waves detected by the transceiver unit Comparing the difference in data with the digital data with the situation representative data to estimate the situation of the space to be monitored;
Spatial monitoring device. A space monitoring method for monitoring a space situation,
Receives the reflected wave sends out a transmission wave when reflected by an object present in the space on the amplitude and spatial be monitored signals in the frequency band of 30~300GHz having a characteristic phase changes, the transmission wave and the The reflected wave is converted into digital data to be transmitted wave data and reflected wave data .
Comparing the transmitted wave data and the reflected wave data to detect a difference on the digital data of both ,
The step includes
Generate a radio frequency signal modulated in a predetermined manner,
Separating the transmission wave of the radio frequency signal and the reflected wave from the space with respect to the transmission wave;
Converting the frequency of the transmitted wave and the reflected wave to a predetermined constant frequency;
Digitally converting the signal of the transmitted wave and the reflected wave converted to a constant frequency ;
Detecting the amplitude and phase of the transmission and the reflected wave from the digital data obtained by the digital conversion, respectively, and detecting the amplitude and phase between the transmission wave and the reflected wave,
Spatial monitoring method.