JP2006153895A - Invasion/obstruction detection device and response device with no power fed - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decrease an incorrect discrimination of invasion/obstruction and to provide a detection device of a low power consumption. <P>SOLUTION: A detection device has the detection device and a response device. The response device comprises a filter for filtering a radio frequency except a specified radio frequency among the radio frequencies received by the detection device; and an antenna for transmitting to the detection device without amplification of the specified radio frequency passing through the filter. Further, the detection device comprises a transmitting means which a plurality of the radio frequencies including a standard radio frequency and the specified radio frequency are transmitted by the antenna to the response device; and a judgement means to judge an existence of the invasion or obstruction based on the existence of a reception of the standard radio frequency and the existence of the reception of the specified radio frequency. The response device transmits the specified radio frequency without the amplification, therefore, the power consumption can be decreased and no power feeding is also possible. The detection device can be dealt with at almost all cases. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a technique for detecting an intrusion or an obstacle.

  For example, in an active intrusion or obstacle detection system such as laser detection, there are cases where it is difficult to detect due to conditions such as the posture, shape, material, and color of the detection target, which may not be detected. In addition, a system using an ultrafine beam light emitting device such as a laser beam and a light receiving device may not operate normally due to being blocked by a weather condition such as snowfall or heavy rain. As a detection method that is not affected by the weather, there is a detection method using an embedded loop coil. However, since it requires a wide range of embedment work, there is a disadvantage that the cost is increased. In addition, in systems using ultra-fine beam emitters and receivers such as laser beams, the beam is so thin that high-precision alignment is required during installation, and even if a slight impact is applied to the device after installation. Since the optical axis is shifted, readjustment work is essential.

  There are also systems that detect intrusions or obstacles using radar. However, when detecting detection signals from multiple targets using radar in an environment where there are many structures around or in an indoor environment, clutter from the surrounding structures (unnecessary reflection from other than the detection target) In some cases, it is difficult to detect the detection signal of the target object.

Further, as a related technique, there is a technique described in JP 2000-19246 A. The present technology provides an obstacle detection system capable of accurately identifying the type of obstacle, particularly an obstacle with a danger such as a collision during traveling, and a radar apparatus suitable for construction of the obstacle detection system, The purpose is to provide a transponder. Each vehicle is equipped with a transponder that amplitude-modulates the received radar wave with a modulation signal Mc having a frequency fc and returns it. A band-pass filter that extracts a signal component in the vicinity of the frequency fc, that is, a signal modulated by a transponder, from a signal IF obtained by mixing the local signal L with the received signal Sr in the FMCW radar device to detect, and its extraction The mixer that generates the second beat signal Sb2 by mixing the signal IFm with the second local signal Lc of the frequency fc, and AD converts this to the ECU A system having an AD converter for feeding. In the present technology, it is assumed that both a modulated signal and a reflected wave are received from a vehicle on which a transponder is mounted, and a case in which only a modulated signal is received is not assumed. Moreover, since it is mounted on a vehicle, the power saving of the transponder is not considered.
JP 2000-19246 A

  In the conventional technology, there is a problem that the reflected wave cannot be directly detected when an intruding object exists in a long-distance area, or when the object that originally exists in the detection area and the intruding object are close to each other. There is a problem that cannot be identified.

  Further, the conventional technology using a transponder assumes a state in which there is no problem in supplying power to the transponder, and does not consider an environment in which it is difficult to supply power. In addition, the case where only the signal from the transponder is received is not considered, and it is assumed that both the signal from the transponder and the reflected wave from the vehicle on which the transponder is mounted are received. There is no viewpoint of distinguishing from other objects.

  Accordingly, an object of the present invention is to provide a novel intrusion / obstacle detection device for reducing erroneous recognition of intrusion / obstacles.

  Another object of the present invention is to provide a novel response device that enables low power consumption and an intrusion / obstacle detection device including the response device.

  The intrusion / obstacle detection device according to the first aspect of the present invention includes a detection device and a response device. And the said response apparatus transmits to the detection apparatus, without amplifying the filter which filters frequencies other than a specific frequency among the frequencies of the electromagnetic wave received from the detection apparatus, and the specific frequency which passed the filter And an antenna. In addition, the detection device includes a transmitting unit that transmits radio waves of a plurality of frequencies including a reference frequency and a specific frequency from the antenna to the response device, presence / absence of reception of a radio wave of the specific frequency, and a reference frequency Determination means for determining the presence or absence of an intrusion or an obstacle based on whether or not a radio wave is received.

  As described above, the response device transmits a radio wave having a specific frequency without being amplified, so that power consumption can be suppressed, and the response device can be installed in a place where it is difficult to supply power from the outside. Some filters operate without power supply, and maintenance work related to the power supply can be saved. Furthermore, if the detection device can detect the presence / absence of reception of radio waves of a specific frequency and the presence / absence of reception of radio waves of a reference frequency, it can cope with almost all cases.

  The intrusion / obstacle detection device according to the second aspect of the present invention includes a detection device and a response device. The response device includes a modulation unit that modulates a signal related to the radio wave received from the detection device, and an antenna that transmits the radio wave related to the signal modulated by the modulation unit to the detection device without amplifying the signal. In addition, the detection device may be intruded or transmitted based on means for transmitting a radio wave of a specific frequency from the antenna to the response device, presence / absence of reception of a radio wave related to the modulated signal, and presence / absence of reception of a radio wave of a specific frequency Determination means for determining the presence or absence of an obstacle.

  As described above, the response device transmits the radio wave related to the modulated signal without being amplified, so that the power consumption can be suppressed, and the response device can be installed in a place where it is difficult to supply power from the outside. Note that a configuration in which modulation is performed without supplying external power is possible, and maintenance work related to the power supply can be saved. Also, the detection device can identify whether there is an intrusion or an obstacle in the vicinity of the response device, for example, depending on whether a modulated radio wave is received and whether a radio wave having a specific frequency is received.

  Note that the antenna of the response device may have a function of suppressing reflection of radio waves from the detection device toward the detection device. In this way, erroneous recognition due to unnecessary reflection can be reduced. In addition, unnecessary reflection can be similarly suppressed by using a circularly polarized antenna as the antenna of the detection device and the response device.

  The parasitic power response device according to the third aspect of the present invention amplifies a filter that filters a frequency other than a specific frequency among frequencies of a radio wave received from the detection device, and a specific frequency radio wave that has passed through the filter. And an antenna for transmitting to the detection device. If such a non-powered response device is used, it can be easily installed in places where there are restrictions on construction and maintenance work such as the vicinity of tracks. If a plurality of parasitic response devices are installed by changing a specific frequency according to each parasitic response device, an intrusion or an obstacle can be detected on the surface.

  There are many configurations for realizing the configuration described above, and the present invention is not limited to the embodiments described below.

  According to the present invention, it is possible to reduce intrusion and erroneous recognition of obstacles.

  As another aspect of the present invention, a novel response device that enables low power consumption and an intrusion / obstacle detection device including the response device can be provided.

[Embodiment 1]
FIG. 1 shows an installation example of the intrusion / obstacle detection device according to the first embodiment of the present invention. FIG. 1 shows an installation example for detecting an intrusion / obstacle at a railroad crossing. The detection apparatus 1a is installed outside the line 3a and the detection apparatus 1b is installed outside the line 3b. A response device 2a, a response device 2b, and a response device 2c are installed on the opposite side of the road 4 with respect to the detection devices 1a and 1b. The response device 2a is installed near the line 3a and on the detection device 1a side, the response device 2b is installed between the lines 3a and 3b and near the center, and the response device 2c is installed near the line 3b and the detection device It is installed on the 1b side. The detection device 1a is connected to the detection device 1b, and the detection device 1b is connected to the alarm device 10.

  As shown by the one-dot chain line in FIG. 1, any response device responds to both the detection devices 1a and 1b, and between the detection device 1a and the response device 2a, the detection device 1a and the response device. 2b, between the detection device 1a and the response device 2c, between the detection device 1b and the response device 2a, between the detection device 1b and the response device 2b, and between the detection device 1b and the response device 2c.・ If there is an obstacle, it can be detected. The installation positions of the detection devices 1a and 1b and the response devices 2a, 2b, and 2c are determined according to the detection area setting status and the like. However, when it is necessary to install between the lines 3a and 3b as in the response device 2b, for example, it may be difficult to supply power from the external power source to the response device 2b. As for the response devices 2a and 2c, when power supply from an external power source is required, a large restriction is imposed on the installation position. Further, if the response devices 2a, 2b, and 2c simply reflect the radar waves from the detection devices 1a and 1b, a problem of erroneous recognition (false detection) may occur.

  Therefore, in the present embodiment, the following configurations are adopted for the response devices 2a, 2b and 2c. As shown in FIG. 2, the response device 2a in the present embodiment (hereinafter, the response device 2a will be described as a representative of the response device) includes a reception antenna 21 and an isolator 23 connected to the reception antenna 21. A carrier filter 25 having an isolator 23 connected to the input terminal, an isolator 24 connected to the output terminal of the carrier filter 25, and a transmitting antenna 22 connected to the isolator 24. The carrier wave filter 25 is, for example, a waveguide type band pass filter (BPF), and operates without supplying power. As schematically shown in FIG. 2, the response device 2a is configured to receive a radio wave having a frequency f1 (eg, a predetermined frequency band centered on the frequency f1) and a frequency f2 (eg, centering on the frequency f2) from the detection device. When the receiving antenna 21 receives a radio wave having a predetermined frequency band, the frequency f1 signal and the frequency f2 signal are supplied to the carrier filter 25 via the isolator 23. In the carrier wave filter 25, for example, in order to filter a signal having a frequency other than the frequency f1, only the signal having the frequency f1 is supplied to the isolator 24. That is, the signal having the frequency f2 is blocked by the carrier wave filter 25. Then, the radio wave having the frequency f1 is transmitted from the transmitting antenna 22 to the detection device without being amplified.

  A detection device 1b for such a response device 2a (hereinafter, the detection device 1b will be described as a representative of the detection device) has a configuration as shown in FIG. That is, the detection device 1b includes a detection device body 11 having an antenna 111 that transmits and receives predetermined radio waves (radio waves used in radar such as millimeter waves and microwaves) and a radar control unit 112 that controls transmission and reception of radio waves, and a detection device. A signal processing unit 121 that processes a signal regarding radio waves transmitted and received in the main body 11 (for example, performs Fast Fourier Transform (FFT) processing), a determination processing unit 122 that determines whether there is an intrusion or an obstacle, and a determination processing unit The determination processing unit 12 includes an alarm processing unit 123 that outputs an alarm signal to the alarm device 10 when it is determined that the intrusion or obstacle exists. The detection device body 11 and the signal processing unit 121 of the determination processing unit 12 are the same as those of the conventional radar device, and detailed description thereof will be omitted below.

  Next, the operation and processing of the detection device 1b will be described with reference to FIGS. As a premise, the carrier filter of the response device 2a filters a signal having a frequency other than the frequency f1, the carrier filter of the response device 2b filters a signal having a frequency other than the frequency f2, and the carrier filter of the response device 2c has a frequency f3. Signals of frequencies other than are filtered. The frequency indicates a frequency band having a predetermined width including the center frequency. First, the radar control unit 112 describes the carrier wave f0 having the frequency f0 (hereinafter referred to as the carrier wave f0 only for simplicity. The same applies to the carrier wave f1 having the frequency f1, the carrier wave f2 having the frequency f2, and the carrier wave f3 having the frequency f3. ), The carrier wave f1, the carrier wave f2, and the carrier wave f3 are sequentially transmitted to the detection region (step S1). When the response device 2a, the response device 2b, and the response device 2c receive the carrier wave f0, the carrier wave f1, the carrier wave f2, and the carrier wave f3, the response device 2a performs filtering by the carrier wave filter, and transmits the radio wave having the frequency passed by the carrier wave filter to the detection device 1b Send back. However, each response device does not send a reply unless it can receive a radio wave having a frequency that passes through the carrier filter.

  The antenna 111 of the detection device 1b receives radio waves (carrier wave f0, carrier wave f1, carrier wave f2, carrier wave f3, though not received) from the detection area (step S3). A signal from the antenna 111 is output to the signal processing unit 121 via the radar control unit 112. The signal processing unit 121 performs FFT processing on the carrier wave f0, the carrier wave f1, the carrier wave f2, and the carrier wave f3 (step S5). Specifically, FFT processing for the beat signal of the carrier wave f0, FFT processing for the beat signal of the carrier wave f1, FFT processing for the beat signal of the carrier wave f2, and FFT processing for the beat signal of the carrier wave f3 are performed.

  The determination processing unit 122 determines whether the FFT processing result for the carrier wave f0 is the same as the FFT processing result for the carrier wave f1 (step S7). For example, in the state shown in FIG. 5A, that is, in the state where no intruder or obstacle exists in the detection area, as shown in FIG. 5B, the carrier wave f0 and the carrier wave f1 transmitted from the detection device 1b are used. Of the carrier waves f2 and f3, only the carrier wave f1 is returned from the response device 2a (only the carrier wave f2 from the response device 2b and only the carrier wave f3 from the response device 2c). Therefore, the carrier wave f0 is not received by the antenna 111 of the detection apparatus 1b, and no peak occurs in the FFT processing result. That is, the FFT processing result (outline) as shown in FIG. In FIG. 6A, the horizontal axis represents the beat frequency of the beat signal, and the vertical axis represents the intensity. On the other hand, since the carrier wave f1 is received by the antenna 111 of the detection device 1b, a peak is also detected in the FFT processing result. That is, the FFT processing result (outline) as shown in FIG. 6B is obtained. Note that the horizontal and vertical axes in FIG. 6B are the same as those in FIG. As described above, if no intruder or obstacle exists in the detection area, the FFT processing result as shown in FIGS. 6A and 6B can be obtained, and the FFT processing result is the same in step S7. It is judged that it is not. If it is determined in step S7 that the FFT processing results are not the same, the processing proceeds to the processing in FIG.

  On the other hand, in the state as shown in FIG. 7A, that is, in the state where the intruder or the obstacle 9 exists between the detection device 1b and the response device 2a, as shown in FIG. 7B, transmission is performed from the detection device 1b. Of the received carrier wave f0, carrier wave f1, carrier wave f2, and carrier wave f3, carrier wave f0 and carrier wave f1 (only carrier wave f2 from response device 2b and only carrier wave f3 from response device 2c) are returned from the direction of response device 2a. The Therefore, since the reflected wave is detected from the same distance for both the carrier wave f0 and the carrier wave f1, an FFT processing result having a similar peak can be obtained. That is, FFT processing results (outline) as shown in FIG. 8A (carrier wave f0) and FIG. 8B (carrier wave f1) are obtained. 8A and 8B are the same as those in FIG. 6A. Thus, if the intruder or the obstacle 9 exists in the detection area, the same FFT processing result can be obtained as shown in FIGS. 8A and 8B, and the FFT processing is performed in step S7. The results are judged to be the same.

  Depending on the state of clutter in the detection area, the detection apparatus 1b may not be able to receive a reflected wave even when an intruder or obstacle 9 exists in the detection area as shown in FIG. However, since only one of the carrier wave f0 and the carrier wave f1 cannot receive the reflected wave, both are always affected in the same way. Therefore, in such a case, an FFT processing result (outline) as shown in FIGS. 9A and 9B is obtained. In FIG. 9A (carrier wave f0) and FIG. 9B (carrier wave f1), the horizontal and vertical axes are the same as those in FIG. As shown in FIGS. 9A and 9B, no peak is detected in either the carrier wave f0 or the carrier wave f1. Therefore, it is determined in step S7 that the FFT processing results are the same.

  If it is determined in step S7 that the FFT processing results are the same, the determination processing unit 122 determines whether both the carrier wave f0 and the carrier wave f1 have been detected (step S9). That is, it is determined whether peaks are detected for both the carrier wave f0 and the carrier wave f1 in the FFT processing result. As shown in FIGS. 9A and 9B, when no peak is detected for both the carrier wave f0 and the carrier wave f1, the determination processing unit 122 determines that the response device A (here, the response device 2a) and the detection device 1b. (Step S17), and notifies the alarm processing unit 123 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S19). In the case where a notification that there is an intruder or an obstacle between the response device A and the like is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the response device A” may be output.

  On the other hand, when both the carrier wave f0 and the carrier wave f1 are detected, the determination processing unit 122 determines whether the FFT processing result is the same as the normal FFT processing result of the carrier wave f1 (step S11). That is, it is determined whether the distance to the intruder or the obstacle is the same as the distance to the response device 2a. The FFT processing results as shown in FIGS. 8A and 8B have been obtained for the current carrier f0 and the carrier f1, and the normal FFT processing results of the carrier f1 are as shown in FIG. 8C. If so, it cannot be determined that the FFT processing results for the carrier wave f0 and the carrier wave f1 are the same as the normal FFT processing result for the carrier wave f1. From the FFT processing results of the carrier wave f0 and the carrier wave f1, the distance to the intruder or the obstacle is shorter than that of the response device 2a. Accordingly, the process proceeds to step S17.

  However, when an intruder or obstacle 9 is close to the response device 2a as shown in FIG. 10 (a), the carrier wave f0 and the carrier wave transmitted from the detection device 1b as shown in FIG. 10 (b). Of f1, carrier f2, and carrier f3, carrier f0 and carrier f1 (only carrier f2 from response device 2b and only carrier f3 from response device 2c) are returned from the direction of response device 2a. Therefore, for both the carrier wave f0 and the carrier wave f1, a reflected wave is detected for the carrier wave f0 and a response from the response device 2a is detected for the carrier wave f1, so that an FFT processing result having a similar peak is obtained. That is, FFT processing results (outline) as shown in FIG. 11A (carrier wave f0) and FIG. 11B (carrier wave f1) are obtained. Note that the horizontal and vertical axes in FIGS. 11A and 11B are the same as those in FIG. When the normal FFT processing result of the carrier wave f1 is as shown in FIG. 11C (same as FIG. 8C), the FFT processing result for the carrier wave f0 and the carrier wave f1 is normal of the carrier wave f1. It can be determined that the result is the same as the FFT processing result. As shown in FIGS. 10 (a) and 10 (b), the distance to the intruder or obstacle 9 in the FFT processing result is almost the same as that of the response device 2a.

  Therefore, the determination processing unit 122 determines that there is an intruder or an obstacle near the response device A (here, the response device 2a) (step S13), and notifies the alarm processing unit 123 to that effect. Upon receiving the notification that there is an intruder or an obstacle, the alarm processing unit 122 outputs an alarm signal to the alarm device 10 (step S15). In the case where a notification that there is an intruder or an obstacle near the response device A is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle near the response device A” may be output. Then, the processing shifts to the processing in FIG. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  Next, the processing after the terminal A will be described with reference to FIG. The determination processing unit 122 determines whether the FFT processing result for the carrier wave f0 is the same as the FFT processing result for the carrier wave f2 (step S21). In step S21, the determination may be made using the FFT processing result for the carrier wave f2 instead of the carrier wave f1 in step S7. If it is determined in step S21 that the FFT processing results are not the same, the process proceeds to step S35.

  If it is determined in step S21 that the FFT processing results are the same, the determination processing unit 122 determines whether both the carrier wave f0 and the carrier wave f2 have been detected (step S23). That is, it is determined whether peaks are detected for both the carrier wave f0 and the carrier wave f2 in the FFT processing result. In step S23, the determination may be made using the FFT processing result for the carrier wave f2 instead of the carrier wave f1 in step S9. When no peak is detected for both the carrier wave f0 and the carrier wave f2, the determination processing unit 122 determines that there is an intruder or an obstacle between the response device B (here, the response device 2b) and the detection device 1b (step S31), and notifies the alarm processing unit 123 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S33). In the case of outputting a notification “There is an intruder or an obstacle between the response device B”, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the responding device B” may be output.

  On the other hand, if both the carrier wave f0 and the carrier wave f2 are detected, the determination processing unit 122 determines whether the FFT processing result is the same as the normal FFT processing result of the carrier wave f2 (step S25). That is, it is determined whether the distance to the intruder or the obstacle is the same as the distance to the response device 2b. In step S25, the determination may be made using the FFT processing result for the carrier wave f2 instead of the carrier wave f1 in step S11. If the FFT processing results of the carrier wave f0 and the carrier wave f2 do not coincide with the normal FFT processing result of the carrier wave f2, and the distance to the intruder or obstacle is closer than the response device 2b, the process proceeds to step S31. To do.

  When it is determined that the FFT processing result of the carrier wave f0 and the carrier wave f2 is substantially the same as the FFT processing result of the carrier wave f2 in the normal state and the distance to the intruder or the obstacle is substantially the same as that of the response device 2b. The processing unit 122 determines that there is an intruder or an obstacle near the response device B (here, the response device 2b) (step S27), and notifies the alarm processing unit 123 to that effect. Upon receiving a notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S29). In the case where a notification that there is an intruder or an obstacle near the response device B is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm according to “There is an intruder or an obstacle near the response device B” may be output. Then, the process proceeds to step S35. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  Next, the determination processing unit 122 determines whether the FFT processing result for the carrier wave f0 is the same as the FFT processing result for the carrier wave f3 (step S35). In step S35, the determination may be made using the FFT processing result for the carrier wave f3 instead of the carrier wave f1 in step S7. If it is determined in step S35 that the FFT processing results are not the same, the process proceeds to step S49.

  If it is determined in step S35 that the FFT processing results are the same, the determination processing unit 122 determines whether both the carrier wave f0 and the carrier wave f3 have been detected (step S37). That is, it is determined whether peaks are detected for both the carrier wave f0 and the carrier wave f3 in the FFT processing result. In step S37, the determination may be made using the FFT processing result for the carrier wave f3 instead of the carrier wave f1 in step S9. If no peak is detected for both the carrier wave f0 and the carrier wave f3, the determination processing unit 122 determines that there is an intruder or an obstacle between the response device C (here, the response device 2c) and the detection device 1b (step S45), and notifies the alarm processing unit 123 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S47). In the case where a notification that there is an intruder or an obstacle between the response device C and the like is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the responding device C” may be output.

  On the other hand, if both the carrier wave f0 and the carrier wave f3 are detected, the determination processing unit 122 determines whether the FFT processing result is the same as the normal FFT processing result of the carrier wave f3 (step S39). That is, it is determined whether the distance to the intruder or the obstacle 9 is the same as the distance to the response device 2c. In step S39, the determination may be made using the FFT processing result for the carrier wave f3 instead of the carrier wave f1 in step S11. If the FFT processing results of the carrier wave f0 and the carrier wave f3 do not coincide with the normal FFT processing result of the carrier wave f3, and the distance to the intruder or obstacle 9 is closer than the response device 2c, the process proceeds to step S45. Transition.

  When it is determined that the FFT processing result of the carrier wave f0 and the carrier wave f3 is substantially the same as the FFT processing result of the carrier wave f3 in the normal state and the distance to the intruder or the obstacle is substantially the same as that of the response device 2c. The processing unit 122 determines that there is an intruder or an obstacle near the response device C (here, the response device 2c) (step S41), and notifies the alarm processing unit 123 to that effect. Upon receiving a notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S43). In the case where a notification that there is an intruder or an obstacle near the response device C is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “there is an intruder or an obstacle near the response device C” may be output. Then, the process proceeds to step S49. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  In step S49, it is determined whether or not the process is to be terminated. If the process is not to be terminated, the process returns to step S1 and the above-described process is repeated. When the process is terminated, the process of the detection device 1b is terminated.

  If such a process is performed, even if a non-powered response device is used, an intruder or an obstacle present in the vicinity of the response device as shown in FIGS. 10A and 10B is also detected. Can reduce recognition errors.

  In addition, about the detection apparatus 1a, the process of the detection apparatus 1b described above is implemented as it is, an alarm signal is transmitted to the detection apparatus 1b, and an alarm is given to the alarm device 10 or the like via the alarm processing unit 123 of the detection apparatus 1b. Output a signal. However, the detection device 1a has fewer functions than the detection device 1b, and for example, the output of the radar control unit 112 or the processing result of the signal processing unit is transmitted to the detection device 1b and processed by the detection device 1b. May be.

  In the above description, the operating principle of the present embodiment has not been described for the sake of clarity. However, since the detection devices 1a and 1b transmit the carrier wave f0, the carrier wave f1, the carrier wave f2, and the carrier wave f3, the response device 2a, The antennas 2b and 2c also receive the carrier wave f0, the carrier wave f1, the carrier wave f2, and the carrier wave f3. Since it leads to recognition, it is not preferable. Therefore, it is preferable to suppress unnecessary reflection by adopting the following configuration for the antenna 21.

  That is, as shown in FIG. 13, when the transmitting antenna 22 and the receiving antenna 21 are installed at a predetermined angle and the incident wave 1300 incident on the transmitting antenna 22 and the receiving antenna 21 is received, The reflected wave 1301 is not returned toward 1b. However, a response must be returned from the transmitting antenna 22 toward the detection device 1a or 1b. That is, the unnecessary reflected wave 1301 is reflected in a different direction so that the detection device 1a or 1b does not detect unnecessary reflection, and the transmitting antenna 22 is directed to the detection device 1a or 1b regardless of the direction of the antenna. An antenna from which the main beam 1302 is radiated is adopted.

  For this reason, for example, a slot antenna using a waveguide or a slot antenna using a microstrip line may be employed as the antenna in the response device. That is, as shown in FIG. 14, the slot antennas connected by the antenna element interval d and the feed line length L between the antenna elements are configured. At this time, if the in-tube wavelength of the feeder line is λg and the spatial wavelength λ, the main beam 1302 is set in the angle θ direction that satisfies the following expression.

  That is, when the antenna in the response device is tilted by the angle θ, the tilt angle of the main beam 1302 may be set to θ by adjusting the antenna element interval d and the feed line length L between the antenna elements. For details, see “Revised Radar Technology”, published by The Institute of Electronics, Information and Communication Engineers; Corona, Inc., first edition issued October 1, 1996, page 128.

  Separately from this, unnecessary reflections can be suppressed by using circularly polarized antennas in the same turning direction (right turn or left turn) for the antennas of the detection device and the response device. This is because circularly polarized waves have a feature that the turning direction is reversed once they are completely reflected, and a circularly polarized antenna has a feature that does not receive polarized waves having different turning directions, and therefore, unnecessary reflection is suppressed. That is, when the circularly polarized radio wave transmitted from the detection device 1b or the like is completely reflected by the antenna of the response device 2a or the like, the turning direction is reversed. It cannot be received by an antenna such as the device 1b. Therefore, unnecessary reflection can be suppressed. For details, see “Microwave Antenna”, Ohm Co., Ltd., issued on January 10, 1959, pages 113 to 114.

  However, you may make it suppress unnecessary reflection using another method.

  In the present embodiment, an example in which the number of response devices is three has been described. However, the number of response devices is not limited to three. The same applies to the following.

[Embodiment 2]
In the first embodiment, the response devices 2a, 2b, and 2c having the reception antenna 21 and the transmission antenna 22 are shown. However, it is not always necessary to use two antennas. It is also possible to use a response device configured as shown in FIG.

  That is, the antenna 150 is connected to the antenna connection terminal of the circulator 151. The input terminal of the carrier wave filter 25 is connected to the reception signal output terminal of the circulator 151. The output terminal of the carrier wave filter 25 is connected to the transmission signal input terminal of the circulator 151. Therefore, a signal about the radio wave received by the antenna 150 is input to the carrier wave filter 25 via the circulator 151, and a predetermined frequency (for example, a predetermined frequency having the frequency f1 as the center frequency) is the same as in the first embodiment. Filter frequencies other than the frequency band). The signal that has passed through the carrier wave filter 25 is supplied to the antenna 150 via the circulator 151, and a radio wave having a specific frequency is transmitted to the detection device 1a or 1b.

  Even if it is such a structure, there exists an effect similar to 1st Embodiment.

[Embodiment 3]
In the first embodiment, the detection devices 1a and 1b transmit in the order of the carrier wave f0, the carrier wave f1, the carrier wave f2, and the carrier wave f3. In the present embodiment, a case where transmission is performed in a different order will be described. The response devices 2a, 2b and 2c and the detection devices 1a and 1b have the same configuration. Also, as a premise, the carrier filter of the response device 2a filters a signal having a frequency other than the frequency f1, the carrier filter of the response device 2b filters a signal having a frequency other than the frequency f2, and the carrier filter of the response device 2c has a frequency f3. Signals of frequencies other than are filtered. The frequency indicates a frequency band having a predetermined width including the center frequency.

  The operation / process flow of the detection apparatus 1b in the present embodiment will be described with reference to FIGS. First, the radar control unit 112 causes the antenna 111 to sequentially transmit the carrier wave f0, the carrier wave f1, the carrier wave f0, the carrier wave f2, the carrier wave f0, and the carrier wave f3 to the detection region (step S51). When the response device 2a, the response device 2b, and the response device 2c receive the carrier wave f0, the carrier wave f1, the carrier wave f0, the carrier wave f2, the carrier wave f0, and the carrier wave f3, the response device 2a performs filtering using the carrier wave filter. A radio wave is returned to the detection device 1b. However, each response device does not send a reply unless it can receive a radio wave having a frequency that passes through the carrier filter.

  The antenna 111 of the detection device 2b receives radio waves (carrier wave f0, carrier wave f1, carrier wave f0, carrier wave f2, carrier wave f0, carrier wave f3, although not received) (step S53). A signal from the antenna 111 is output to the signal processing unit 121 via the radar control unit 112. The signal processing unit 121 performs FFT processing on the carrier wave f0, the carrier wave f1, the carrier wave f0, the carrier wave f2, the carrier wave f0, and the carrier wave f3 (step S55). Specifically, FFT processing for the beat signal of the carrier wave f0, FFT processing for the beat signal of the carrier wave f1, FFT processing for the beat signal of the carrier wave f0, FFT processing for the beat signal of the carrier wave f2, beat signal of the carrier wave f0 FFT processing is performed, and FFT processing is performed on the beat signal of the carrier wave f3.

  Next, the determination processing unit 122 determines whether the FFT processing result for the carrier wave f1 is the same as the FFT processing result for the previous carrier wave f0 (step S57). The process in step S57 is the same as the process in step S7 in the first embodiment. If it is determined in step S57 that the FFT processing results are not the same, the processing shifts to the processing in FIG.

  If it is determined in step S57 that the FFT processing results are the same, the determination processing unit 122 determines whether both the carrier wave f0 and the carrier wave f1 have been detected (step S59). That is, it is determined whether peaks are detected for both the carrier wave f0 and the carrier wave f1 in the FFT processing result. The process in step S59 is the same as step S9 in the first embodiment. If no peak is detected for both the carrier wave f0 and the carrier wave f1, the determination processing unit 122 determines that there is an intruder or an obstacle between the response device A (here, the response device 2a) and the detection device 1b (step S67), the alarm processing unit 123 is notified to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S69). In the case where a notification that there is an intruder or an obstacle between the response device A and the like is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the response device A” may be output.

  On the other hand, when both the carrier wave f0 and the carrier wave f1 are detected, the determination processing unit 122 determines whether the FFT processing result is the same as the normal FFT processing result of the carrier wave f1 (step S61). That is, it is determined whether the distance to the intruder or the obstacle is the same as the distance to the response device 2a. The process of step S61 is the same as step S11 in the first embodiment. If the FFT processing results of the carrier wave f0 and the carrier wave f1 do not coincide with the normal FFT processing result of the carrier wave f1, and the distance to the intruder or the obstacle is shorter than the response device 2a, the process proceeds to step S67. To do.

  When it is determined that the FFT processing result of the carrier wave f0 and the carrier wave f1 is substantially the same as the FFT processing result of the carrier wave f1 in the normal state and the distance to the intruder or the obstacle is substantially the same as that of the response device 2a. The processing unit 122 determines that there is an intruder or an obstacle near the response device A (here, the response device 2a) (step S63), and notifies the alarm processing unit 123 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S65). In the case where a notification that there is an intruder or an obstacle near the response device A is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle near the response device A” may be output. Then, the processing shifts to the processing in FIG. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  Next, the processing after the terminal C will be described with reference to FIG. The determination processing unit 122 determines whether the FFT processing result for the carrier wave f2 is the same as the FFT processing result for the previous carrier wave f0 (step S71). In step S71, the determination may be made using the FFT processing result for the carrier wave f2 instead of the carrier wave f1 in step S57. For the carrier wave f0, the FFT processing result of the second carrier wave f0 is used. If it is determined in step S71 that the FFT processing results are not the same, the process proceeds to step S83.

  If it is determined in step S71 that the FFT processing results are the same, the determination processing unit 122 determines whether both the carrier wave f0 and the carrier wave f2 have been detected (step S73). That is, it is determined whether peaks are detected for both the carrier wave f0 and the carrier wave f2 in the FFT processing result. In step S73, the determination may be made using the FFT processing result for the carrier wave f2 instead of the carrier wave f1 in step S59. For the carrier wave f0, the FFT processing result of the second carrier wave f0 is used. When no peak is detected for both the carrier wave f0 and the carrier wave f2, the determination processing unit 122 determines that there is an intruder or an obstacle between the response device B (here, the response device 2b) and the detection device 1b (step S80), and notifies the alarm processing unit 123 to that effect. Upon receiving the notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S81). In the case of outputting a notification “There is an intruder or an obstacle between the response device B”, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the responding device B” may be output.

  On the other hand, when both the carrier wave f0 and the carrier wave f2 are detected, the determination processing unit 122 determines whether the FFT processing result is the same as the normal FFT processing result of the carrier wave f2 (step S75). That is, it is determined whether the distance to the intruder or the obstacle is the same as the distance to the response device 2b. In step S75, the determination may be made using the FFT processing result for the carrier wave f2 instead of the carrier wave f1 in step S61. For the carrier wave f0, the FFT processing result of the second carrier wave f0 is used. If the FFT processing results of the carrier wave f0 and the carrier wave f2 do not match the normal FFT processing result of the carrier wave f2, and the distance to the intruder or the obstacle is closer than the response device 2b, the process proceeds to step S80. To do.

  When it is determined that the FFT processing results of the carrier wave f0 and the carrier wave f2 are substantially the same as the FFT processing result of the carrier wave f2 in the normal state and the distance to the intruder or the obstacle is substantially the same as that of the response device 2b. The processing unit 122 determines that an intruder or an obstacle exists near the response device B (here, the response device 2b) (step S77), and notifies the alarm processing unit 123 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S79). In the case where a notification that there is an intruder or an obstacle near the response device B is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm according to “There is an intruder or an obstacle near the response device B” may be output. Then, the process proceeds to step S83. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  Next, the determination processing unit 122 determines whether the FFT processing result for the carrier wave f3 is the same as the FFT processing result for the previous carrier wave f0 (step S83). In step S83, the determination may be made using the FFT processing result for the carrier wave f3 instead of the carrier wave f1 in step S57. The third carrier f0 is also used for the carrier f0. If it is determined in step S83 that the FFT processing results are not the same, the process proceeds to step S97.

  If it is determined in step S83 that the FFT processing results are the same, the determination processing unit 122 determines whether both the carrier wave f0 and the carrier wave f3 have been detected (step S85). That is, it is determined whether peaks are detected for both the carrier wave f0 and the carrier wave f3 in the FFT processing result. In step S85, the determination may be made using the FFT processing result for the carrier wave f3 instead of the carrier wave f1 in step S59. The third carrier f0 is also used for the carrier f0. If no peak is detected for both the carrier wave f0 and the carrier wave f3, the determination processing unit 122 determines that there is an intruder or an obstacle between the response device C (here, the response device 2c) and the detection device 1b (step S93), and notifies the alarm processing unit 123 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S95). In the case where a notification that there is an intruder or an obstacle between the response device C and the like is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the responding device C” may be output.

  On the other hand, when both the carrier wave f0 and the carrier wave f3 are detected, the determination processing unit 122 determines whether the FFT processing result is the same as the normal FFT processing result of the carrier wave f3 (step S87). That is, it is determined whether the distance to the intruder or the obstacle is the same as the distance to the response device 2c. In step S87, the determination may be made using the FFT processing result for the carrier wave f3 instead of the carrier wave f1 in step S61. The third carrier f0 is also used for the carrier f0. If the FFT processing results of the carrier wave f0 and the carrier wave f3 do not coincide with the normal FFT processing result of the carrier wave f3, and the distance to the intruder or the obstacle is closer than the response device 2c, the process proceeds to step S93. To do.

  When it is determined that the FFT processing result of the carrier wave f0 and the carrier wave f3 is substantially the same as the FFT processing result of the carrier wave f3 in the normal state and the distance to the intruder or the obstacle is substantially the same as that of the response device 2c. The processing unit 122 determines that there is an intruder or an obstacle near the response device C (here, the response device 2c) (step S89), and notifies the alarm processing unit 123 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 123 outputs an alarm signal to the alarm device 10 (step S91). In the case where a notification that there is an intruder or an obstacle near the response device C is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “there is an intruder or an obstacle near the response device C” may be output. Then, the process proceeds to step S97. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  In step S97, it is determined whether or not to end the process. If the process is not ended, the process returns to step S51 and the above-described process is repeated. When the process is terminated, the process of the detection device 1b is terminated.

  If such a process is carried out, an intruder or an obstacle present in the vicinity of the response device as shown in FIGS. 10A and 10B can be detected even if a non-powered response device is used. Can reduce misrecognition.

[Embodiment 4]
In the first to third embodiments, the detection devices 1a and 1b must transmit many types of carriers according to the number of response devices, such as carrier wave f0, carrier wave f1, carrier wave f2, and carrier wave f3. Don't be. Therefore, in the present embodiment, the types of transmission carriers of the detection devices 1a and 1b are reduced by adopting the following configuration.

  The configuration of the response device 2a (hereinafter, the response device 2a will be described as a representative of the response device) will be described with reference to FIG. The response device 2 a is connected to the receiving antenna 181, the isolator 182 connected to the receiving antenna 181, the transmitter 184 that outputs a signal of frequency fs, the output terminal of the isolator 182 and the transmitter 184, and the antenna 181. The modulation unit 183 that modulates the signal corresponding to the carrier wave fr having the frequency fr received by the signal with the frequency fs from the transmitter 184, the isolator 185 connected to the output terminal of the modulation unit 183, and the isolator 185 And a transmitting antenna 186. The frequency fs of the signal generated by the transmitter 184 differs for each responding device. A signal having the frequency fmr generated by modulating the signal corresponding to the carrier wave fr with the signal having the frequency fs is transmitted as the modulated carrier wave fmr from the transmitting antenna 186 to the detection device 1a or 1b without being amplified. The That is, a modulated carrier wave fmr that is different for each response device is transmitted to the detection device 1a or 1b.

  In the response device 2a of the present embodiment, the transmitter 184 and the modulation unit 183 require power except for the configuration described later. However, since amplification is not performed, it is possible to operate with low power consumption. Therefore, long-time operation with a small-sized storage battery and continuous operation with a small-scale solar cell or wind power generator are possible. Therefore, the response device can be installed even in an environment where external power feeding is difficult.

  On the other hand, the detection device 1b of the present embodiment (the detection device 1b will be described as a representative of the detection device) has a configuration as shown in FIG. The detection apparatus 1b includes a detection apparatus main body 191 having an antenna 1911 that transmits and receives predetermined radio waves (radio waves used in radar such as millimeter waves and microwaves) and a radar control unit 1912 that controls transmission and reception of radio waves, and a detection apparatus main body 191. A filter (that is, a band pass filter or a band elimination filter) 1921 that passes or removes a signal about a radio wave received in a specific frequency band and a signal that has passed through the filter 1921 are processed (for example, FFT processing is performed) ) A signal processing unit 1922 and a determination processing unit 1923 that determines whether there is an intrusion or an obstacle, and an alarm processing unit that outputs an alarm signal to the alarm device 10 when the determination processing unit 1923 determines that there is an intrusion or an obstacle. And a judgment processing unit 192 having 1924. The detection device main body 191 and the filter 1921 and the signal processing unit 1922 of the determination processing unit 192 are the same as those of the conventional radar device and will not be described in detail below.

  Next, the operation and processing of the detection device 1b will be described with reference to FIGS. As a premise, the modulation unit of the response device 2a performs modulation at the frequency fs1, the modulation unit of the response device 2b performs modulation at the frequency fs2, and the modulation unit of the response device 2c performs modulation at the frequency fs3. And First, the radar control unit 1912 causes the antenna 1911 to transmit the carrier wave fr having the frequency fr to the detection area (step S101). When the response device 2a receives the carrier wave fr, the response device 2a modulates at the frequency fs1, and when the response device 2b receives the carrier wave fr, the response device 2b modulates at the frequency fs2 and modulates at the frequency fmr2. When the response device 2c receives the carrier wave fr, the response device 2c modulates at the frequency fs3 and transmits a modulated carrier wave fmr3 of the frequency fmr3 to the detection device 1b. However, each response device does not send a reply unless it can receive a carrier wave from the detection device 1b.

  The antenna 1911 of the detection device 1b receives each carrier wave (carrier wave fr, modulated carrier wave fmr1, modulated carrier wave carrier fmr2, and modulated carrier wave carrier fmr3, although not received) (step S103). A signal from the antenna 1911 is output to the filter 1921 via the radar control unit 1912. The filter 1921 first performs filtering so that only the modulated carrier wave fmr1 from the response device A (here, the response device 2a) is passed (step S105). For example, a band pass filter (BPF) of a predetermined frequency band having the modulated carrier wave fmr1 as the center frequency is configured to process a signal on the received carrier wave. Then, the filtered signal is output to the signal processing unit 1922. The signal processing unit 1922 performs FFT processing on the filtered signal (step S107). Specifically, FFT processing is performed on the beat signal of the modulated carrier wave fmr1.

  The determination processing unit 1923 determines whether a peak is detected in the FFT processing result (step S109). For example, in the state shown in FIG. 21A, that is, in the state where no intruder or obstacle exists in the detection area, as shown in FIG. 21B, it corresponds to the carrier wave fr transmitted from the detection apparatus 1b. The response device 2a returns a modulated carrier wave fmr1 (the modulated device carrier frequency fmr2 from the response device 2b and the modulated carrier wave device fmr3 from the response device 2c). Therefore, the signal for the modulated carrier wave fmr1 passes through the filter, and an FFT processing result (outline) having a peak as shown in FIG. In FIG. 22A, the horizontal axis represents the beat frequency of the beat signal, and the vertical axis represents the intensity.

  On the other hand, in the state as shown in FIG. 23A, that is, in the state where the intruder or the obstacle 9 exists between the detection device 1b and the response device 2a, as shown in FIG. Corresponding to the received carrier fr, only the carrier fr is returned from the direction of the response device 2a (the modulated carrier FMr2 from the response device 2b and the modulated carrier FMr3 from the response device 2c). Therefore, no signal passes through the filtering in step S105. That is, an FFT processing result (outline) without a peak as shown in FIG. 22B is obtained. Note that the horizontal and vertical axes in FIG. 22B are the same as those in FIG.

  In this manner, if no peak is detected in the FFT processing result for the filtered signal in step S105, the determination processing unit 1923 determines whether there is an intruder between the response device A (here, the response device 2a) and the detection device 1b. It is determined that there is an obstacle (step S111), and the alarm processing unit 1924 is notified to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 1924 outputs an alarm signal to the alarm device 10 (step S113). In the case where a notification that there is an intruder or an obstacle between the response device A and the like is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the response device A” may be output. The processing shifts to the processing in FIG.

  On the other hand, when a peak is detected in the FFT processing result in step S109, the filter 1921 performs filtering so as to remove only the modulated carrier wave fmr1 from the response device A (the response device 2a in this case) (step S115). . For example, a filter that filters only a predetermined frequency band having the frequency fmr1 of the modulated carrier wave fmr1 as a center frequency is configured to process a signal on the received carrier wave. However, since the frequency bands of the modulated carrier wave fmr2 and the modulated carrier wave fmr3 are not used here, filtering is performed so as to filter. Then, the filtered signal is output to the signal processing unit 1922. The signal processing unit 1922 performs FFT processing on the filtered signal (step S117). Specifically, FFT processing is performed on beat signals of components other than the modulated carrier wave fmr1.

  For example, in the state shown in FIG. 21A, that is, in the state where no intruder or obstacle exists in the detection area, as shown in FIG. 21B, it corresponds to the carrier wave fr transmitted from the detection apparatus 1b. The response device 2a returns a modulated carrier wave fmr1 (the modulated device carrier frequency fmr2 from the response device 2b and the modulated carrier wave device fmr3 from the response device 2c). Therefore, since the modulated carrier wave fmr1 (and the modulated carrier wave fmr2 and the modulated carrier wave fmr3) are filtered, an FFT processing result (outline) without a peak as shown in FIG. 22B is obtained.

  On the other hand, as shown in FIG. 24A, when an intruder or obstacle 9 is close to the response device 2a, it corresponds to the carrier wave fr transmitted from the detection device 1b as shown in FIG. Then, the carrier fr and the modulated carrier fmr1 (the modulated carrier fmr2 from the response device 2b and the modulated carrier fmr3 from the response device 2c) are returned from the direction of the response device 2a. Therefore, in the filtering in step S105, only the signal for the modulated carrier wave fmr1 passes, so the FFT processing result is as shown in FIG. That is, the same FFT processing result as that in the case where there is no intruder or obstacle is the same as in FIG. On the other hand, since the carrier wave fr is also received as a reflected wave, only the signal for the carrier wave fr passes through the filtering in step S115, and the FFT processing result is as shown in FIG. That is, it is the same as FIG.

  Therefore, the determination processing unit 1923 determines whether the same beat frequency (that is, peak) is detected in the FFT processing result in step S107 and the FFT processing result in step S117 (step S119). As described above, in the state shown in FIG. 21A and FIG. 21B, the FFT processing result is obtained as a combination of FIG. 22A and FIG. It does not match. Accordingly, it is determined that there are no intruders or obstacles, and the process proceeds to the process of FIG.

  On the other hand, in the state shown in FIG. 24A and FIG. 24B, the FFT processing results are obtained as a combination of FIG. 25A and FIG. 25B, so the beat frequencies match. Accordingly, the determination processing unit 1923 determines that there is an intruder or an obstacle near the response device A (here, the response device 2a) (step S121), and notifies the alarm processing unit 1924 to that effect. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 1924 outputs an alarm signal to the alarm device 10 (step S123). In the case where a notification that there is an intruder or an obstacle near the response device A is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle near the response device A” may be output. Then, the processing shifts to the processing in FIG. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  Next, the processing after the terminal E will be described with reference to FIGS. The filter 1921 performs filtering so that the signals from the antenna 1911 and the radar control unit 1912 pass only the modulated carrier wave fmr2 from the response device B (here, the response device 2b) (step S125). For example, a band pass filter (BPF) in a predetermined frequency band having the modulated carrier wave fmr2 as the center frequency is configured to process a signal on the received carrier wave. Then, the filtered signal is output to the signal processing unit 1922. The signal processing unit 1922 performs FFT processing on the filtered signal (step S127). Specifically, FFT processing is performed on the beat signal of the modulated carrier wave fmr2.

  The determination processing unit 1923 determines whether a peak has been detected in the FFT processing result (step S129). Step S129 is the same process as step S109. As described above, if no peak is detected in the FFT processing result of the filtered signal in step S125, the determination processing unit 1923 enters between the response device B (here, the response device 2b) and the detection device 1b. It is determined that there is an obstacle or an obstacle (step S131), and that is notified to the alarm processing unit 1924. Upon receiving a notification that there is an intruder or an obstacle, the alarm processing unit 1924 outputs an alarm signal to the alarm device 10 (step S133). In the case of outputting a notification “There is an intruder or an obstacle between the response device B”, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the responding device B” may be output. The processing shifts to the processing in FIG.

  On the other hand, when a peak is detected in the FFT processing result in step S129, the filter 1921 performs filtering so as to remove only the modulated carrier wave fmr2 from the response device B (here, the response device 2b) (step S135). . For example, a filter that filters only a predetermined frequency band having a frequency fmr2 of the modulated carrier wave fmr2 as a center frequency is configured to process a signal on the received carrier wave. However, since the frequency bands of the modulated carrier wave fmr1 and the modulated carrier wave fmr3 are not used here, filtering is performed so as to filter. Then, the filtered signal is output to the signal processing unit 1922. The signal processing unit 1922 performs FFT processing on the filtered signal (step S137). Specifically, FFT processing is performed on beat signals of components other than the modulated carrier wave fmr2.

  Then, the determination processing unit 1923 determines whether the same beat frequency (that is, peak) is detected in the FFT processing result in step S127 and the FFT processing result in step S137 (step S139). As described above, if the beat frequencies do not match, it is determined that there is no intruder or obstacle, and the process proceeds to the process of FIG. On the other hand, if the beat frequencies match, the determination processing unit 1923 determines that there is an intruder or an obstacle near the response device B (here, the response device 2b) (step S141), and an alarm processing unit 1924 to that effect. Notify Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 1924 outputs an alarm signal to the alarm device 10 (step S143). In the case where a notification that there is an intruder or an obstacle near the response device B is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm according to “There is an intruder or an obstacle near the response device B” may be output. Then, the processing shifts to the processing in FIG. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  Next, processing after the terminal G will be described with reference to FIG. The filter 1921 performs filtering so that the signal from the antenna 1911 and the radar control unit 1912 passes only the modulated carrier wave fmr3 from the response device C (here, the response device 2c) (step S145). For example, a band pass filter (BPF) of a predetermined frequency band having the modulation carrier wave fmr3 as the center frequency is configured, and a signal for the received carrier wave is processed. Then, the filtered signal is output to the signal processing unit 1922. The signal processing unit 1922 performs FFT processing on the filtered signal (step S147). Specifically, FFT processing is performed on the beat signal of the modulated carrier wave fmr3.

  The determination processing unit 1923 determines whether a peak is detected in the FFT processing result (step S149). Step S149 is the same process as step S109. As described above, if no peak is detected in the FFT processing result of the filtered signal in step S145, the determination processing unit 1923 enters between the response device C (here, the response device 2c) and the detection device 1b. It is determined that there is an obstacle or an obstacle (step S151), and that is notified to the alarm processing unit 1924. Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 1924 outputs an alarm signal to the alarm device 10 (step S153). In the case where a notification that there is an intruder or an obstacle between the response device C and the like is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “There is an intruder or an obstacle between the responding device C” may be output. The process proceeds to step S165.

  On the other hand, if a peak is detected in the FFT processing result in step S149, the filter 1921 performs filtering so as to remove only the modulated carrier wave fmr3 from the response device C (here, the response device 2c) (step S155). . For example, a filter that filters only a predetermined frequency band having the frequency fmr3 of the modulated carrier wave fmr3 as a center frequency is configured to process a signal on the received carrier wave. However, since the frequency bands of the modulated carrier wave fmr1 and the modulated carrier wave fmr2 are not used here, filtering is performed so as to filter. Then, the filtered signal is output to the signal processing unit 1922. The signal processing unit 1922 performs FFT processing on the filtered signal (step S157). Specifically, FFT processing is performed on beat signals of components other than the modulated carrier wave fmr3.

  Then, the determination processing unit 1923 determines whether the same beat frequency (that is, peak) is detected in the FFT processing result in step S147 and the FFT processing result in step S157 (step S159). As described above, if the beat frequencies do not match, it is determined that there is no intruder or obstacle, and the process proceeds to step S165. On the other hand, if the beat frequencies match, the determination processing unit 1923 determines that there is an intruder or an obstacle near the response device C (here, the response device 2c) (step S161), and an alarm processing unit 1924 to that effect. Notify Upon receiving notification that there is an intruder or an obstacle, the alarm processing unit 1924 outputs an alarm signal to the alarm device 10 (step S163). In the case where a notification that there is an intruder or an obstacle near the response device C is output, an alarm signal corresponding to the notification may be output to the alarm device 10. The alarm device 10 outputs an alarm according to the alarm signal. An alarm corresponding to “there is an intruder or an obstacle near the response device C” may be output. Then, the process proceeds to step S165. The alarm signal may be output not only to the alarm device 10 but also to other devices.

  In step S165, it is determined whether or not to end the process. If the process is not ended, the process returns to step S101 and the above-described process is repeated. When the process is terminated, the process of the detection device 1b is terminated.

  If such a process is performed, even if a power-saving response device is used, an intruder or an obstacle present in the vicinity of the response device can be detected, and erroneous recognition can be reduced. In addition, when natural energy can be used, it is not necessary to supply power to the response device from the outside, and it may be said that there is substantially no power supply.

  The transmitter 184 such as the response device 2a may use a PN signal generator, and the modulation unit 183 may perform modulation according to the PN signal generated by the PN signal generator. In this case, the detection apparatus also performs signal processing corresponding to the modulation according to the PN signal. The necessity for suppressing unnecessary reflection is the same in this embodiment, and the configuration described in the first embodiment can be applied to this embodiment.

  Further, the response device 2a and the like can adopt a configuration as shown in FIG. That is, instead of the transmitter 184, a switching unit 281 having a propeller rotated by wind or the like and performing switching according to the rotation of the propeller or the like to the modulation unit 183a is used. Note that it is preferable to have a structure in which the rotation speed of a propeller or the like can be mechanically adjusted, for example, and switched at a constant cycle. The modulation unit 183a modulates the signal corresponding to the received carrier wave fr in accordance with the switching by the switching unit 281. By adopting such a configuration, it is possible to modulate the carrier wave without feeding. Since the modulation is performed by switching, it is necessary to change the configuration so that the detection device can detect the presence or absence of modulation by switching in the signal of the received carrier wave.

  Further, the configuration in which the antenna of the response device is single as shown in FIG. 15 can also be adopted in the response device in the present embodiment.

  Further, the cooperation of the detection devices 1a and 1b can be performed in the same manner as in the first embodiment.

[Embodiment 5]
In the first to fourth embodiments, the height of the intruder or the obstacle is not particularly considered. However, it may be necessary to detect how high an intruder or obstacle exists at a level crossing.

  In such a case, for example, a configuration as shown in FIG. 29 is adopted. That is, the detection device 1b is installed at a height h from the ground. In addition, the response device 291, the response device 292, and the response device 293 are installed at the same point, but the response device 291 is set to a height h3 from the ground, the response device 292 is set to a height h2 from the ground, and the response device 293 is set to the ground. It is assumed that it is installed at a height h1. Note that h1 <h <h2 <h3.

  For example, as shown in FIG. 29, when the intruder or the obstacle 9 exists, the carrier waves from the response devices 293 and 292 cannot be detected, and only the carrier wave from the response device 291 is detected. Since the response device 292 is higher than the detection device 1b, if the intruder or obstacle 9 is higher than the detection device 1b, the carrier wave from the response device 292 is blocked. Then, from the relationship h1 <h <h2 <h3, it is estimated that the intruder or obstacle 9 has a height from h to h3. In addition, since the angle θ with respect to the horizontal line segment connecting the detection device 1b and the response device 292 is known in a steady state, if the distance r to the intruder or the obstacle 9 is known, the intruder or the obstacle 9 It can be estimated that the height is not less than h + r × sin θ. However, the number of response devices is not limited to three. A combination with the first to fourth embodiments is also possible.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment described above. For example, the functional block configuration of the detection apparatus describes functional block division for explaining the functions to the last, and is not necessarily disassembled into programs or parts.

  In the above-described embodiment, the distance value to the intruder or the obstacle is not particularly mentioned, but the distance value may be recorded or output as necessary.

(Appendix 1)
An intrusion / obstacle detection device having a detection device and a response device,
The response device is not powered,
A filter that filters frequencies other than a specific frequency among the frequencies of radio waves received from the detection device;
An antenna that transmits to the detection device without amplifying radio waves of a specific frequency that has passed through the filter;
Have
The detection device is:
Transmitting means for transmitting radio waves of a plurality of frequencies including a reference frequency and the specific frequency from the antenna to the response device;
Judging means for judging the presence or absence of an intrusion or an obstacle based on the presence or absence of reception of radio waves of the specific frequency and the presence or absence of reception of radio waves of the reference frequency;
Intrusion / obstacle detection device.

(Appendix 2)
An intrusion / obstacle detection device having a detection device and a response device,
The response device is:
Modulation means for modulating a signal related to the radio wave received from the detection device;
An antenna for transmitting to the detection device without amplifying radio waves related to the signal modulated by the modulation means;
Have
The detection device is:
Means for transmitting a radio wave of a specific frequency from the antenna to the response device;
A judging means for judging the presence or absence of an intrusion or an obstacle based on the presence or absence of reception of radio waves related to the modulated signal and the presence or absence of reception of radio waves of the specific frequency;
Intrusion / obstacle detection device.

(Appendix 3)
The intrusion / obstacle detection device according to supplementary note 1 or 2, wherein an antenna of the response device has a function of suppressing reflection of radio waves from the detection device toward the detection device.

(Appendix 4)
The determination means is
The intrusion / obstacle detection device according to appendix 1, wherein the presence / absence of an intruder or an obstacle is further determined based on a distance of a transmission source of the received radio wave.

(Appendix 5)
The specific frequency is set for each response device;
The transmitting means is
The intrusion / obstacle detection device according to appendix 1, wherein the antenna is configured to transmit a pair of radio waves having the reference frequency and the radio waves having the specific frequency in order of the response device.

(Appendix 6)
The specific frequency is set for each response device;
The transmitting means is
The intrusion / obstacle detection device according to claim 1, wherein the antenna transmits a combination of a radio wave having the reference frequency and a radio wave having the specific frequency for each of the response devices.

(Appendix 7)
A filter for filtering frequencies other than a specific frequency among radio wave frequencies received from the detection device;
An antenna that transmits to the detection device without amplifying radio waves of a specific frequency that has passed through the filter;
A non-powered response device.

(Appendix 8)
An intrusion / obstacle detection device having a detection device and a response device,
The response device has an antenna,
Transmitting the radio wave according to a frequency different from the frequency of the radio wave received from the detection device to the detection device without amplification,
The antenna has a function of suppressing reflection of radio waves from the detection device toward the detection device,
The detection device is:
Intrusion / obstacle detection characterized in that the presence / absence of an intrusion or obstacle is determined based on the presence / absence of reception of a reflected wave of a radio wave transmitted to the response device and the presence / absence of reception of a radio wave transmitted from the response device apparatus.

(Appendix 9)
9. The intrusion / fault detection object device according to any one of appendices 1 to 6 and 8, wherein the response device is non-powered.

(Appendix 10)
The antenna of the response device is a circularly polarized antenna,
The intrusion / fault detection object device according to appendix 3, wherein the antenna of the detection device is also a circularly polarized antenna.

It is a figure which shows the example of installation of the detection apparatus and response apparatus in embodiment of this invention. It is a functional block diagram of the response apparatus in 1st Embodiment. It is a functional block diagram of the detection apparatus in 1st Embodiment. It is a figure which shows the 1st part of the processing flow in 1st Embodiment. (A) And (b) is a schematic diagram for showing a state in case an intruder or an obstacle does not exist in the first embodiment. (A) And (b) is a figure which shows the FFT process result (outline | summary) when an intrusion or an obstruction does not exist in 1st Embodiment. (A) And (b) is a schematic diagram for showing a state in case an intruder or an obstacle exists between the response device and the detection device in the first embodiment. (A), (b), and (c) show an example of the FFT processing result (outline) when an intruder or an obstacle exists between the detection device and the response device in the first embodiment. FIG. (A) And (b) is a figure which shows an example of the FFT process result (outline | summary) when an intruding object or an obstruction exists between a detection apparatus and a response apparatus in 1st Embodiment. (A) And (b) is a schematic diagram for showing a state in case an intruder or an obstacle exists in the vicinity of the response device in the first embodiment. (A), (b) and (c) are diagrams showing the FFT processing result (outline) when an intruder or an obstacle exists in the vicinity of the responding device in the first embodiment. It is a figure which shows the 2nd part of the processing flow in 1st Embodiment. It is a figure which shows the outline | summary of the response apparatus which has a function which suppresses unnecessary reflection. It is a figure which shows an example of the antenna for suppressing unnecessary reflection. It is a functional block diagram of the response apparatus in 2nd Embodiment. It is a figure which shows the 1st part of the processing flow in 3rd Embodiment. It is a figure which shows the 2nd part of the processing flow in 3rd Embodiment. It is a functional block diagram of the response apparatus in 4th Embodiment. It is a functional block diagram of the detection apparatus in 4th Embodiment. It is a figure which shows the 1st part of the processing flow in 4th Embodiment. (A) And (b) is a schematic diagram for showing a state in case an intruder or an obstacle does not exist in the fourth embodiment. (A) And (b) is a figure which shows a FFT process result (outline). (A) And (b) is a mimetic diagram for showing a state in case an intruder or an obstacle exists between a response device and a detection device in a 4th embodiment. (A) And (b) is a schematic diagram for demonstrating a state in case an intruder or an obstruction exists in the vicinity of a response device in 4th Embodiment. (A) And (b) is a figure which shows a FFT process result (outline). It is a figure which shows the 2nd part of the processing flow in 4th Embodiment. It is a figure which shows the 3rd part of the processing flow in 4th Embodiment. It is a functional block diagram which shows the other example of the response apparatus in 4th Embodiment. It is a figure which shows the positional relationship of the response apparatus in 5th Embodiment, a detection apparatus, an intruder, or an obstruction.

Explanation of symbols

1a, 1b Detection device 2a, 2b, 2c Response device 3a, 3b Track 4 Road 9 Intruder or obstacle 10 Alarm 11, 191 Detection device body 12, 192 Judgment processing unit 21, 181 Reception antenna 22, 186 Transmission Antenna 23, 24, 182, 185 Isolator 25 Carrier filter 151 Circulator 150 Antenna 183, 183a Modulator 184 Transmitter 111, 1911 Antenna 112, 1912 radar control unit 121, 1922 Signal processor 122, 1923 Determination processor 123 , 1924 Alarm processor 1921 Filter

Claims (2)

An intrusion / obstacle detection device having a detection device and a response device,
The response device has an antenna,
Transmitting the radio wave according to a frequency different from the frequency of the radio wave received from the detection device to the detection device without amplification,
The antenna has a function of suppressing reflection of radio waves from the detection device toward the detection device,
The detection device is:
Intrusion / obstacle detection characterized in that the presence / absence of an intrusion or obstacle is determined based on the presence / absence of reception of a reflected wave of a radio wave transmitted to the response device and the presence / absence of reception of a radio wave transmitted from the response device apparatus.   The intrusion / fault detection device according to claim 2, wherein the response device is non-powered.

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