JP5696621B2 - Sensing system - Google Patents

Description

The present invention relates to a sensing system. The present invention can be applied to, for example, a sensing system that determines the state of an object in space using radio waves.

  Conventionally, for example, a sensor system that detects opening and closing of a door is widely used in the world.

  FIG. 2 is an explanatory diagram illustrating a conventional sensor system that detects opening and closing of a door, for example. FIG. 2 illustrates a sensor system 90 that detects opening and closing of a door 92 provided in a space 91 such as a housing or a room.

  In FIG. 2, there is a sensor 93 that detects the opening and closing of the door 92 in the vicinity of the door 92, and a controller 94 that controls some operation based on sensor data from the sensor 93. The sensor 93 to the controller 94 are connected by a cable 95, and sensor data is transmitted to the controller 94 through the cable 95. The conventional sensor system 90 illustrated in FIG. 2 requires the laying of the cable 95. The laying of the cable 95 requires construction work and time, and the cable 95 is exposed so that the appearance is not desirable. It was.

  On the other hand, in order to eliminate the cable for transmitting sensor data, electric waves are transmitted intermittently, and changes in electric field strength due to reflection, absorption, and scattering of radio waves are caused by human actions when entering and exiting and opening and closing of doors. There is a sensing system that can determine whether a door is opened or closed by detecting it (see Patent Document 1 and Patent Document 2).

JP 2005-4256 A JP 2010-255270 A

  However, the methods described in Patent Literature 1 and Patent Literature 2 can detect a change in state such as opening and closing of a door, for example, but cannot determine a difference in door state.

  Each of the technologies described in Patent Document 1 and Patent Document 2 uses changes in reflected wave fluctuation (that is, simple electric field strength) generated when a door is opened and closed. In this case, the fluctuation occurs due to the opening / closing of the door, and further, the fluctuation occurs due to the movement of the person. Therefore, the technologies described in Patent Document 1 and Patent Document 2 can detect some state change based on the fluctuation of the reflected wave.

  However, the techniques described in Patent Document 1 and Patent Document 2 cannot detect whether the door is in an open state or a closed state. In other words, the technology described in Patent Document 1 and Patent Document 2 is an application that only needs to be able to detect any change, whether by opening or closing the door or by movement of a person. There may be a problem that it is not possible to distinguish an absolute state difference such as whether it is in a closed state or in a closed state.

  In addition, for example, in a narrow and complex space, small fluctuations constantly occur, so that there may be a problem that it is not possible to respond to the desire to detect the distinction of the state of a specific object (detected body).

Therefore, by utilizing the variation of the delayed wave power, sensing system to be able to determine the state of the detected body it is strongly required in space.

In order to solve such a problem, the first aspect of the present invention is (1) one or a plurality of detected objects that are fixedly arranged in a space and have a plurality of states that can change the reflection mode of transmitted radio waves. A delay time calculating means for calculating a delay time from the time of transmission of radio waves to the time of reception of radio waves reflected by the detected object in the first state, and (2) radio wave transmission means for transmitting radio waves (3) a radio wave receiving means for receiving a reflected radio wave of the radio wave emitted by the radio wave transmitting means and continuously sampling the received power value of the received incoming wave at a sufficiently short interval to obtain the received power value of the incoming wave; (4) power delay data acquisition means for acquiring power delay data indicating fluctuations in time-series received power values of delay waves received from the time of radio wave transmission by the radio wave reception means; (5) referring to power delay data; each subject calculated by the delay time calculating means State determining means for determining the state of each detected object based on the received power value at the arrival time of the delayed wave corresponding to the body delay time, and the state determining means corresponds to the delay time of each detected object When the received power value at the arrival time exceeds the threshold, it is determined that the detected object is in the first state in which the radio wave is reflected, and the received power value at the arrival time corresponding to the delay time of each detected object is equal to or less than the threshold. In this case, it is determined that the detected object is in the second state in which the radio wave arriving at the radio wave receiving means is reflected after the arrival time without reflecting the radio wave arriving at the radio wave receiving means at the arrival time. Is a sensing system characterized by

  According to the present invention, it is possible to determine the state of an object to be detected in space by using fluctuations in the power of delayed waves.

It is a block diagram which shows the structure of the sensing system of this invention. It is explanatory drawing explaining the conventional sensor system. It is a whole lineblock diagram showing the whole sensing system composition of a 1st embodiment. It is explanatory drawing explaining a power delay profile in 1st Embodiment. It is explanatory drawing explaining a power delay profile in 1st Embodiment. It is explanatory drawing explaining the basic concept of the method of discriminating the state of a to-be-detected object using a power delay profile in 1st Embodiment. It is a flowchart which shows the operation | movement which detects the state of the to-be-detected body by the electromagnetic wave sensor part in 1st Embodiment. In 1st Embodiment, it is explanatory drawing explaining the method of detecting the open state of a door. In 1st Embodiment, it is explanatory drawing explaining the method to detect the closed state of a door. In 2nd Embodiment, it is explanatory drawing explaining the method to detect the open state of two doors. In 2nd Embodiment, it is explanatory drawing explaining the method to detect the closed state of two doors. In 2nd Embodiment, it is explanatory drawing explaining the method of detecting the open state of one door, and the closed state of the other door.

(A) Basic concept of this invention The sensing system of this invention detects the state of the to-be-detected body which is the target of state detection.

  Usually, radio waves are reflected and received by various objects. At this time, since each reflection wave has a different reflection path, it arrives with a delay due to a difference in the distance of the reflection path of the element wave, and is generally received as a combined power value of each element wave.

  On the other hand, in the sensing system of the present invention, since the reflected radio wave is delayed and received by the receiver, the time series fluctuation of the received power value of the delayed wave is measured and the time series of the received power value is measured. The state of the detected object is determined based on the fluctuation.

  In the sensing system, the radio wave transmitted by the transmission unit is reflected by the detection target, the reflected radio wave is received by the reception unit, and the reception unit confirms the power change of the fundamental wave. That is, the sensing system includes an elementary wave arrival time calculating means for calculating the arrival time of the elementary wave reflected by the detected object, and a power measurement for measuring the power value (electric field strength) of the elementary wave that arrives at the receiving unit with a delay. Means.

  Here, the measurement result of the time series fluctuation of the received power value of the incoming wave is referred to as a “power delay profile”. That is, the sensing system of the present invention discriminates the state of the detected object using the power delay profile.

  Therefore, the sensing system of the present invention includes power delay profile measuring means for measuring the power delay profile. Alternatively, there is provided means for detecting the state of the detected object by measuring the fluctuation of the received power of the delayed wave using the received power of the delayed wave, which is equivalent to the power delay profile measuring means.

  The power delay profile is acquired when the receiving unit receives radio waves at high-speed sampling intervals. Therefore, the sensing system can obtain a power delay profile as a discrete received power value at each sampling point.

  The sensing system refers to the power delay profile and determines the state of the detected object based on the arrival time of the wave reflected by the detected object. That is, when the received power value at the arrival time of the wave reflected by the detected object is large, the detected object can be reflected, and when the received power value is small, the detected object cannot be reflected. Can be determined.

(B) In the following first embodiment, the first embodiment of the sensing system of the present invention will be described in detail with reference to the drawings.

(B-1) Configuration of the First Embodiment (B-1-1) Overall Configuration FIG. 3 is an overall configuration diagram illustrating the overall configuration of the sensing system of the first embodiment. FIG. 3 is an overall configuration diagram when the sensing system 10 of the first embodiment is installed in a space 1 such as a housing or a room.

  It is assumed that a door 2 is provided in the space 1 and that an obstacle 5 is placed in the space 1, and the sensing system 10 of the first embodiment is in the open state or the closed state of the door 2. The case where it detects is illustrated.

  The door 2 is an example of a detected object whose state is detected by the sensing system 10. It is assumed that the position of the door 2 is fixed and the distance from the radio wave sensor unit 3 is constant. Accordingly, the radio wave sensor unit 3 is assumed to recognize in advance the distance from itself to the door 2 that is the detection target.

  Here, the object to be detected can change into any two or more states, and the reflection mode of the transmitted radio wave can be changed with the state change. In this embodiment, although the case where a to-be-detected body is the door 2 is illustrated, a to-be-detected body is not limited to the door 2, It can apply widely.

  Further, the number of objects to be detected may be one or plural. In this embodiment, the case where the one door 2 is made into a detected body is illustrated.

  Further, the detected object may be provided with a reflector (reflector) made of a metal or the like so that the radio wave can be effectively totally reflected. Of course, when the material of the object to be detected is made of metal or the like, it is not necessary to provide a new reflector.

  In FIG. 3, the sensing system 10 of the first embodiment includes a radio wave sensor unit 3, and the radio wave sensor unit 3 is connected to a controller 4.

  The radio wave sensor unit 3 includes a transmission unit 31 and a reception unit 32, and the reception unit 32 receives the radio wave transmitted from the transmission unit 31 and reflected back. The radio wave sensor unit 3 discriminates an open state or a closed state of the door 2 that is a detection target based on a change in power of the radio wave received by the receiving unit 32. The radio wave sensor unit 3 gives the determination result to the controller 4. It is assumed that the position of the radio wave sensor unit 3 is fixedly arranged in advance.

  3 illustrates a case where only one radio wave sensor unit 3 is arranged, but a plurality of radio wave sensor units 3 may be arranged. Even when a plurality of radio wave sensor units 3 are arranged, the positions of the radio wave sensor units 3 are fixedly arranged, and each radio wave sensor unit 3 is a distance between the detected object and the radio wave sensor unit 3. Are recognized in advance.

  The controller 4 receives the determination result of the open state or the closed state of the door 2 by the radio wave sensor unit 3, and performs a predetermined control process based on the determination result. The control process performed by the controller 4 is not particularly limited, and various processes using the determination result can be widely applied.

(B-1-2) Detailed Configuration of Sensing System 10 FIG. 1 is a block diagram showing a detailed internal configuration of the radio wave sensor unit 3 constituting the sensing system 10. The radio wave sensor unit 3 includes circuit devices such as a CPU, a ROM, a RAM, an EEPROM, and an input / output interface, for example. Various functions of the radio wave sensor unit 2 are performed, for example, by the CPU executing a processing program stored in the ROM.

In FIG. 1, the radio wave sensor unit 3 includes a transmission unit 31, a reception unit 32, a power delay profile calculation unit 33, a sensing position database 34, a delay time calculation unit 35, and a sensing determination unit 36.

The transmission unit 31 transmits radio waves for measuring the power delay profile. The transmission unit 31 transmits radio waves having a predetermined frequency. Here, the frequency of the radio wave transmitted by the transmission unit 31 is not particularly limited. The transmission unit 31 gives the power delay profile calculation unit 33 the transmission timing for transmitting radio waves. As a result, it is possible to notify the power delay profile calculation unit 33 of the radio wave transmission time necessary to calculate the power delay profile.

  The receiving unit 32 receives the reflected incoming wave for the radio wave transmitted by the transmitting unit 31 and measures the received power value of the elementary wave. As a result, it is possible to measure time-series fluctuations in the received power value of the delayed wave. The receiving unit 32 gives the received power value of the elementary wave to the power delay profile calculating unit 33.

  As illustrated in FIG. 1, the reception unit 32 includes a reception intensity measurement unit 321 and a high-speed sampling circuit unit 322.

  The reception intensity measurement unit 321 is an incoming wave reception power measurement unit that measures temporal variations in the reception power value of an arrival wave captured by an antenna unit (not shown).

  The high-speed sampling circuit unit 322 obtains a discrete received power value by sampling the measurement result of the temporal variation of the received power value of the incoming wave obtained by the received intensity measuring unit 321 at a high-speed sampling interval. It is. The high-speed sampling circuit unit 322 gives the reception time and the reception power value to the power delay profile calculation unit 33 as discrete reception power values.

  Here, in order to increase the accuracy of the power delay profile, it is desirable that the sampling interval of the high-speed sampling circuit unit 322 be high speed. For example, the sampling interval is determined according to the size of the space 1, the distance between the door 2, which is the detection target, and the radio wave sensor unit 3, but the distance between the door 2 and the radio wave sensor unit 3 is It is desirable that the shorter the sampling interval, the faster the sampling interval.

  The power delay profile calculation unit 33 is based on the timing at which the transmission unit 31 transmits radio waves and the discrete reception power value from the reception unit 32 (that is, the reception power value at the reception time of the radio waves received by the reception unit 32). Thus, a power delay profile is obtained. That is, the power delay profile calculation unit 33 creates a power delay profile in which the reception power value at each reception time is developed on the time axis with the radio wave transmission time as a reference.

  4 and 5 are explanatory diagrams for explaining the power delay profile. FIG. 4 is an explanatory diagram for explaining the measurement result of the temporal variation of the received power value of the incoming wave. FIG. 5 is an explanatory diagram for explaining the measurement result of the discrete received power value of the incoming wave by the high-speed sampling circuit unit 322. 4 and 5, the horizontal axis represents time, and the vertical axis represents the received power value of the incoming wave.

  The radio wave transmitted by the transmitter 31 is reflected by various objects and arrives at the receiver 32 after being delayed. Therefore, as shown in FIG. 4, the reflected element wave arrives with a delay, and the received power value of the element wave varies with time.

  As shown in FIG. 5, the high-speed sampling circuit unit 322 samples the received power value of the incoming wave illustrated in FIG. 4 at the sampling interval, and the power delay profile calculation unit 33 acquires the discrete received power value. .

  Based on the discrete reception power value from the high-speed sampling circuit unit 322 and the transmission time of the transmission unit 31, the power delay profile calculation unit 33 calculates the reception power value of the delayed wave from the transmission time, as shown in FIG. Create a power delay profile showing time-series variations.

  The sensing position database 34 stores position information of all sensing positions. That is, the sensing position database 34 uses, for example, the position information of the transmission unit 31, the position information of the reception unit 32, the position information of the detected object (for example, the door 2), the position information of the obstacle 5, and the like as the position information of the sensing position. Store.

  For example, the sensing position database 34 sets a reference position in the space 1, and stores coordinate information of the transmission unit 31, the reception unit 32, the door 2, and the like as position information. The reference position in the space 1 can be arbitrarily set. For example, the position of the transmission unit 31 can be set as the reference position. The coordinate information may be two-dimensional coordinates or three-dimensional coordinates.

  The sensing position database 34 may store distance information obtained by summing the distance from the transmission unit 31 to the door 2 and the distance from the door 2 to the reception unit 32.

  The sensing position database 34 provides the delay time calculation unit 35 with the stored position information of each sensing position when determining the state of the door 2 that is the object to be detected.

  When the delay time calculation unit 35 acquires the position information of each sensing position stored in the sensing position database 34, the delay time between the transmission unit 31 and the door 2 and the distance between the door 2 and the reception unit 32 are obtained. And the sum of the distance between the transmission unit 31 and the door 2 and the distance between the door 2 and the reception unit 32 is obtained. Thereby, the total distance of the radio wave path until the radio wave transmitted from the transmitter 31 is reflected by the door 2 and directly reaches the receiver 32 can be obtained.

  The delay time calculation unit 35 holds the radio wave speed (approximately 300,000 km per second), and calculates the delay time of the incoming wave based on the total distance of the radio wave path reflected on the door 2 and the radio wave speed. It is what you want. The delay time calculation unit 35 gives the obtained delay time information to the sensing determination unit 36.

  The sensing determination unit 36 receives the power delay profile from the power delay profile calculation unit 33 and the delay time information from the delay time calculation unit 35, and based on the result of the received power value at the delay time of the power delay profile, The state of the door 2 which is a body is determined. The sensing determination unit 36 gives the determination result of the state of the door 2 to the controller 4.

  Here, a method for determining the state of the detected object using the power delay profile will be described.

  FIG. 6 is an explanatory diagram for explaining the basic concept of a method for determining the state of the detected object using the power delay profile. FIG. 6 illustrates a case where the open state or the closed state of the door 2 is determined as two or more states of the detection target.

  FIG. 6A shows an example of a power delay profile, and FIG. 6B shows an example of the state of the door 2 in the space 1.

  The positional information of the transmitting unit 31 and the receiving unit 32 and the positional information of the door 2 that is the detection target are arranged in advance and registered in advance. Accordingly, the total distance of the radio wave path is obtained based on the distance from the transmission unit 31 and the door 2 and the distance from the door 2 to the reception unit 32.

  If the total distance of the radio wave path is required, the transmission unit 31 and the reception unit 32 do not need to be provided in one module, and may be provided outside the module.

First, based on the total distance of the radio wave path with respect to the detected object and the speed of the radio wave (for example, about 300,000 km per second), the radio wave transmitted from the transmission unit 31 is reflected on the door 2 and the reflected elementary wave Can be obtained by the delay time calculation unit 35 (S101). Here, for example, the arrival time of rays reflected in the door 2 is assumed to be T _D.

  The sensing determination unit 36 continuously acquires power delay profiles by high-speed sampling from the power delay profile calculation unit 33.

  Since the sensing determination unit 36 recognizes the arrival time of the wave reflected on the door 2 (S102), the sensing determination unit 36 determines the state of the door 2 based on the received power value at the arrival time of the wave.

  For example, when the door 2 is in the closed state, the radio wave is reflected by the door 2, so that the received power value of the element wave changes higher than the adjacent received power value. Therefore, the sensing determination unit 36 can determine that the door 2 is closed when the received power value at the arrival time is a relatively large value. On the other hand, when the door 2 is in the open state, the wave reflected on the door 2 does not arrive at the receiving unit 32, or the route becomes longer and the arrival time at the receiving unit 32 is further delayed. The received power value is a value that does not change even when compared with the adjacent received power value. Therefore, in such a case, the sensing determination unit 36 can determine that the door 2 is open (S103).

  In the above example, the case where the detected object is the door 2 is illustrated for convenience of explanation, but the present invention is not limited to the door 2. For example, the radio wave reflection path may change depending on the orientation of the object to be detected. In this case as well, since the reflected radio wave changes the arrival time of the reflected radio wave at the receiving unit 32, the sensing determination unit 36 can determine the state of the arrangement direction of the detected object.

(B-2) Operation of the First Embodiment Next, the operation of detecting the state of the detected object by the radio wave sensor unit 3 of the first embodiment will be described with reference to the drawings.

  FIG. 7 is a flowchart illustrating the state detection operation of the detection target in the radio wave sensor unit 3 according to the first embodiment.

  Here, as shown in FIG. 3, a door 2 is attached to a space 1 such as a housing, and the radio wave sensor unit 3 detects an open state or a closed state of the door 2.

  In FIG. 7, first, the transmission unit 31 transmits a radio wave (S201). For convenience of explanation, it is assumed that the radio wave transmitted from the transmission unit 31 is composed of, for example, two typical elementary waves.

  In the space 1 illustrated in FIG. 3, an obstacle 5 may be arranged in addition to the door 2 that is a detection target. This is because even if there is an obstacle 5, radio waves have the property of traveling around the obstacle 5 unlike light. Here, the distance that the radio wave travels around the obstacle 5 is very small and can be ignored.

  The radio wave transmitted from the transmission unit 31 is reflected by the door 2 that is the detection target, and the reflected elementary wave is captured by the reception unit 32. The receiving unit 32 measures temporal variation of the received power value of the reflected elementary wave (S202).

  It is desirable that the radio wave reflected by the door 2 is not absorbed by the door 2 but totally reflected. Therefore, in order to enable total reflection, for example, a reflective plate made of a metal or the like may be provided on the door 2.

  When the temporal variation of the received power value of the reflected elementary wave is measured, in the receiving unit 32, the high-speed sampling circuit unit 322 performs a high-speed sampling of the temporal variation of the received power value at a sampling interval, and performs discrete processing. Received power value data is obtained (S203).

  The power delay profile calculation unit 33 creates a power delay profile based on a series of discrete reception power value data from the reception unit 32 with reference to the transmission time from the transmission unit 31.

  On the other hand, the delay time calculation unit 35 reflects the radio wave received by the reception unit 32 after being reflected by the door 2 based on the position information of the transmission unit 31, the reception unit 32, and the door 2 stored in the sensing position database 34. Find the total distance of the journey. Based on the total distance of the radio wave path and the speed of the radio wave, an arrival time at which the elementary wave reflected on the door 2 arrives at the receiving unit 32 is obtained (S204).

  The sensing determination unit 36 of the radio wave sensor unit 3 determines the state of the door 2 based on the received power value at the arrival time in the power delay profile, based on the arrival time of the reflected wave reflected on the door 2 (S205). .

  FIG. 8 is an explanatory diagram for explaining a method of detecting the open state of the door 2. FIG. 8A is an explanatory diagram illustrating a path of radio waves from the transmission unit 31 and a path of elementary waves reflected to the door 2 when the door 2 is in the open state in the space 1. FIG. 8B is a diagram illustrating an example of a power delay profile.

  As shown in FIG. 8A, the radio wave transmitted from the transmission unit 31 is reflected by the obstacle 5, the wall, the ceiling, and the like, and the reflected radio wave is received by the reception unit 32. Even if the obstacle 5 is present, the radio wave travels around the obstacle 5. Therefore, as shown in FIG. 8A, even when the door 2 is ahead of the obstacle 5 from the transmission unit 31, the radio wave travels around the obstacle 5 to the door 2 and is reflected by the door 2.

  As shown in FIG. 8A, when the door 2 is in the open state, the elementary wave reflected by the door 2 does not reach the receiving unit 32 directly. That is, the elementary wave reflected on the door 2 is reflected on the wall or the like and can be received by the receiving unit 32 in a multi-dimensional manner, but the path becomes longer. Therefore, the arrival time until the reflected elementary wave arrives at the receiving unit 32 can be delayed.

For example, in FIG. 8 (B), the the arrival time of radio waves reflected on the door 2 arrives directly receiving portion 32 is arrival time T _D. If the door 2 is open, the radio wave arrival time is delayed, if the received power value at time T _D from the radio wave transmission time does not exceed the threshold value (S206), sensing determination unit 36 door 2 in the open state It is determined that there is (S208).

  FIG. 9 is an explanatory diagram for explaining a method of detecting the closed state of the door 2. FIG. 9A is an explanatory diagram for explaining a path of radio waves from the transmission unit 31 and a path of elementary waves reflected on the door 2 when the door 2 is in the closed state in the space 1. FIG. 9B is a diagram illustrating an example of a power delay profile.

As shown in FIG. 9A, when the door 2 is in the closed state, the wave reflected by the door 2 reaches the receiving unit 32 directly. In this case, as shown in FIG. 9 (B), it determines that the reception power value at time _{T D} from the radio wave transmission time exceeds a threshold value (S206), sensing the determination unit 36 has a door 2 in the closed state (S207 ).

  The sensing determination unit 36 notifies the controller 4 of the determination result of the state of the door 2. The controller 4 performs a predetermined process based on the determination result from the sensing determination unit 36.

(B-3) Effects of the First Embodiment As described above, according to the first embodiment, the means for calculating the arrival time of the elementary wave reflected by the door that is the detected object is delayed. Since there is a means for measuring the electric field strength of the incoming elementary wave, it is possible to determine the two states of the door opening and closing.

(C) Second Embodiment Next, a second embodiment of the sensing system of the present invention will be described with reference to the drawings.

(C-1) Configuration and Operation of Second Embodiment The sensing system of the second embodiment will be described with respect to an embodiment in which there are a plurality of doors that are detected bodies.

  Since the configuration of the sensing system of the second embodiment is the same as that of the first embodiment, the second embodiment will be described with reference to FIG. Also in the second embodiment, the basic operation in which the sensing system 10 detects the state of the detected object is the same as that in the first embodiment.

  Therefore, in the second embodiment, an operation in which the sensing system 10 detects the states of the two doors will be described.

  10-12 is explanatory drawing explaining the operation | movement in which the sensing system 10 detects the state of the two doors 21 and 22 when the two doors 21 and 22 are provided in the space 1. FIG.

The arrival time of the wave reflected on the doors 21 and 22 can be obtained in the same manner as in the first embodiment. Here, the arrival time of rays reflected in the door 21 and the arrival time T _1, the arrival time of rays reflected in the door 22 and the arrival time T _2.

  FIG. 10 is an explanatory diagram illustrating a case where the sensing system 10 detects the state of the doors 21 and 22 when the two doors 21 and 22 are both open. FIG. 10A is an explanatory diagram illustrating a path of radio waves from the transmission unit 31 of the radio wave sensor unit 3. FIG. 10B is a diagram illustrating an example of a power delay profile.

  As shown in FIG. 10 (A), when the doors 21 and 22 are in the open state, none of the elementary waves reflected on the doors 21 and 22 reach the receiving unit 32 directly. That is, the elementary waves reflected on the doors 21 and 22 can be reflected on the wall or the like and received by the receiving unit 32 in a multi-order manner, but the path becomes longer. Therefore, the arrival time until the reflected elementary wave arrives at the receiving unit 32 can be delayed.

Thus, in FIG. 10 (B), the case the door 21 is open, since the radio wave arrival time is slow, because the received power value at time T ₁ from the radio wave transmission time does not exceed the threshold value, the sensing determination unit 36 It determines with the door 21 being an open state. Similarly, when the door 22 is in the open state, the received power value at time T2 from the radio wave transmission time does not exceed the threshold value, so the sensing determination unit 36 determines that the door 21 is in the open state.

  In this way, the sensing determination unit 36 determines that both the doors 21 and 22 are open.

  FIG. 11 is an explanatory diagram illustrating a case where the sensing system 10 detects the state of the doors 21 and 22 when the doors 21 and 22 are in a closed state. FIG. 11A is an explanatory diagram illustrating the path of the radio wave from the transmission unit 31 of the radio wave sensor unit 3 and the path of the reflected radio wave. FIG. 11B is a diagram illustrating an example of a power delay profile.

As shown in FIG. 11A, when both the door 21 and the door 22 are in the closed state, the elementary wave reflected by the door 21 reaches the receiving unit 32 directly. Accordingly, as shown in FIG. 11 (B), the reception power value at time T ₁ from the radio wave transmission time exceeds the threshold value, the sensing determination unit 36 determines that the door 21 is closed. Similarly, elementary waves reflected by the door 22, so arrive directly receiving unit 32, the received power value at the time T _2, the radio wave transmission time exceeds the threshold value, the sensing determination unit 36 the door 22 is closed Is determined.

  FIG. 12 is an explanatory diagram illustrating a case where the sensing system 10 detects the state of the doors 21 and 22 when the door 21 is in the open state and the door 22 is in the closed state. FIG. 12A is an explanatory diagram illustrating the path of the radio wave from the transmission unit 31 of the radio wave sensor unit 3 and the path of the reflected radio wave. FIG. 12B is a diagram illustrating an example of a power delay profile.

As shown in FIG. 12A, when the door 21 is in an open state, any of the elementary waves reflected on the door 21 do not reach the receiving unit 32 directly. Accordingly, it is determined in FIG. 12 (B), the since the received power value at time T ₁ from the radio wave transmission time does not exceed the threshold value, a sensing determination unit 36 the door 21 is open.

On the other hand, as shown in FIG. 12A, when the door 22 is in the closed state, the elementary wave reflected by the door 22 reaches the receiving unit 32 directly. Accordingly, as shown in FIG. 12 (B), since the received power value at the time T _2, the radio wave transmission time exceeds the threshold value, the sensing determination unit 36 determines that the door 21 is closed.

(C-3) Effect of Second Embodiment As described above, according to the second embodiment, even when there are a plurality of doors that are detected bodies, the same as in the first embodiment, It is possible to determine the open / closed state of the door.

(D) Other Embodiments (D-1) In the first and second embodiments described above, a door provided in a space such as a housing has been described as an example of the detected object. It is not limited. For example, as long as the position information of the detection target can be held, the object may be a fixedly arranged object or, for example, a medium such as a passing paper. When a medium such as paper is used as the detection object, it can be realized by providing a reflection plate or the like on the paper.

(D-2) In the first and second embodiments described above, the case where one sensing system is provided in one space is illustrated, but a plurality of sensing systems may be provided in one space. In this case, it is not necessary to provide a plurality of transmission units as long as fluctuations in the received power value of the delayed wave can be captured in the reception unit, one transmission unit emits radio waves, and each of the plurality of reception units reflects each other. You may make it acquire the fluctuation | variation of the received power value of a delay wave by receiving the transmitted elementary wave.

(D-3) In the first and second embodiments described above, the case where the power delay profile is generated using the discrete received power value at each sampling point is illustrated. However, as illustrated in FIG. The received power value of the radio wave to be used may be used.

(D-4) In the first and second embodiments described above, the case where there is one threshold for determining the state of the detection target is illustrated, but a plurality of thresholds may be provided. Thereby, for example, when the object to be detected is a door, it is possible to discriminate between a fully opened open state and a case where the detected object is not fully opened (that is, the door is half open). That is, when the door is half open, the received power value can be larger than when the door is closed and smaller than when the door is fully open, so that the radio wave sensor unit can also determine when the door is half open.

(D-5) In the above-described second embodiment, the case where the same threshold value is used for each of the door 21 and the door 22 is illustrated, but different threshold values may be provided for the door 21 and the door 22, respectively.

  Further, the threshold value may be arbitrarily set depending on the material of the detection object.

(D-6) After the delay time calculation unit calculates the delay time of one or more detected objects, the sensing position database stores the delay time of each detected object calculated by the delay time calculation unit. Also good.

DESCRIPTION OF SYMBOLS 1 ... Space 2, 21, and 22 ... Door, 3 ... Radio wave sensor part,
31 ... Transmitter, 32 ... Receiver, 33 ... Power delay profile calculator,
34 ... Session position database, 35 ... Delay time calculation section,
36: Sensing determination unit.

Claims (2)

The above-mentioned detected state in the first state from the time of transmission of the radio wave for each one or a plurality of to-be-detected bodies that are fixedly arranged in the space and can change the reflection mode of the transmitted radio wave A delay time calculating means for calculating a delay time until reception of the radio wave reflected by the body,
Radio wave transmission means for transmitting radio waves;
A radio wave receiving means for receiving a reflected radio wave of the radio wave emitted by the radio wave transmitting means and continuously sampling a received power value of the received incoming wave at a sufficiently short interval to obtain a received power value of the incoming wave;
Power delay data acquisition means for acquiring power delay data indicating fluctuations in time-series received power values of delay waves received from the time of radio wave transmission by the radio wave reception means;
Referring to the power delay data, based on the received power value at the arrival time of the delayed wave corresponding to the delay time of each of the detection object calculated by the delay time calculating means, determining a state of each sensing object And a state determination means for
If the received power value at the arrival time corresponding to the delay time of each detected object exceeds a threshold, the state determining means determines that the detected object is in a first state that reflects radio waves, and If the received power value at the arrival time corresponding to the delay time of each detected object is less than or equal to the threshold value, the detected object is delayed from the arrival time without reflecting the radio wave arriving at the radio wave receiving means at the arrival time. A sensing system, characterized in that it is determined to be in a second state in which radio waves arriving at the radio wave receiving means are reflected . The one or more objects to be detected include a door disposed in the space,
2. The sensing system according to claim 1, wherein the first state is a closed state of the door that is the detected body, and the second state is an open state of the door that is the detected body. .

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