JP5145810B2 - Object identification device and object identification method, and vehicle equipped with object identification device - Google Patents

Description

  The present invention relates to an object identification technique for detecting an amount of radiation in a radio wave region radiated from an object and detecting the object, and a vehicle such as a passenger car using the object identification technique.

Of external recognition devices mounted on vehicles such as passenger cars, reflection-type observation devices such as radar devices are mainly used as devices for detecting vehicles such as preceding vehicles. On the other hand, as a device for detecting a pedestrian, a far-infrared camera is used that measures the temperature from far-infrared radiation intensity radiated from an object and detects an object close to a human body temperature.
In addition, a radio wave imaging device (radio wave receiving system) that observes the amount of radiation in a radio wave region such as millimeter waves is also used (see, for example, Patent Document 1). By observing the amount of radiation of objects in the radio wave area in this way, it is possible to detect the presence of hidden objects or to determine the presence or identification of surrounding objects in situations where visibility is poor due to fog, etc. It is used for security purposes and as a safety device for aircraft takeoff and landing.
JP 2006-322833 A

  A passive radiation amount observation device such as a far-infrared camera observes a radiation amount and identifies an object from the radiation intensity. However, when a radio wave imaging device that is a radiological radiation device in the radio wave region is used among the passive radiation device, if there are other wireless devices operating within the observed frequency band, There was a problem that radio waves transmitted from the device were mistaken for radiation from the object itself, and the object was identified incorrectly.

  That is, the amount of radiation from an object in the radio wave region is very small as calculated by Planck's radiation law, and the radio wave transmitted from the wireless device is very large compared to that. For this reason, even though a wireless device is actually present, the object is observed as an object having a high emissivity and a high temperature, and misidentification occurs in the object identification determination.

  The object identification device according to the present invention has band dividing means. The band dividing means receives radio waves radiated from the detection target object and outputs a plurality of band-specific detection signals corresponding to the plurality of radiation amount observation bands. The present invention further includes comparing radio wave radiation amounts represented by the plurality of band-specific detection signals so that an external radio signal radiated from other than the detection target object is mixed in any of the band-specific detection signals. Determination means for determining whether or not there is. And when it is determined by the determination means that the external radio signal is mixed, the band-specific detection signal in which the external radio signal is mixed is excluded from the plurality of band-specific detection signals. , Generating an image based on the radiation intensity of the detection target object, on the other hand, if it is determined by the determination means that the external radio signal is not mixed, using all of the plurality of band-specific detection signals, In order to generate an image based on the radiation intensity of the detection target object, an image processing unit is provided.

  According to the present invention, the observation frequency band in the radio wave region is divided into a plurality of reception frequency bands, and the amount of radiation (radiation intensity) observed in the plurality of divided reception frequency bands is compared. Therefore, for example, in a band that shows a significantly different amount of radiation (radiation intensity), it is judged that there are other wireless devices that transmit undesirable radio waves, and the radiation amount (radiation intensity) in other bands is used. By performing the object identification, it is possible to accurately detect the radiation amount from the object without being disturbed by a radio signal from a wireless device or the like.

[First Embodiment]
A first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the present invention is applied to an object identification device mounted on a vehicle such as a passenger car.
FIG. 1A is a block diagram illustrating a configuration of an object identification device 100 according to the present embodiment. As illustrated in FIG. 1A, the object identification device 100 includes a radio wave imaging unit 200, a radiation intensity image, and the like. A generation unit 300 and an object recognition processing unit 400 are included. The object identification device 100 is connected to a vehicle control device 500 that controls the running state of the vehicle based on the information obtained by the object recognition processing unit 400. The vehicle control device 500 includes a map data file 601. Is connected to the navigation system 600.

  In the object identification device 100, as an example, the radio wave imaging unit 200 is installed in the vicinity of the front bumper 1 of the vehicle MB as shown in FIG. 1B, and is a radio wave region from an object existing in the space in front of the vehicle MB. The radiation intensity signal in the radio wave region is acquired by detecting the amount of radiation. As an example, the frequency (observation frequency band) of the radio wave region to be detected by the radio wave imaging unit 200 of the present embodiment is a millimeter wave that is less affected by atmospheric propagation attenuation in order to perform object observation at a longer distance outdoors. It is 30 to 39 GHz (10 to 7.7 mm in wavelength) in the band.

  The radiation intensity image generation unit 300 in FIG. 1A generates a radiation intensity image from a radiation intensity signal acquired by each radio wave receiving element (to be described later) of the radio wave imaging unit 200 and an array number of each radio wave receiving element. Spatial regions are grouped (divided) for each intensity to extract information on the region where the object exists (spatial position and shape) and information on the radiation amount from the object, and output the extracted information to the object recognition processing unit 400 To do. The object recognition processing unit 400 identifies an object existing in front of the vehicle from the spatial position and shape of the object output from the radiation intensity image generation unit 300 and information on the radiation amount, and the identification result is sent to the vehicle control device 500. Output.

  FIG. 2 is a diagram illustrating the configuration of the radio wave imaging unit 200 illustrated in FIG. 1A. In FIG. 2, the radio wave imaging unit 200 includes a dielectric lens unit 201 that collects radiation in the radio wave region from an object. A reception array unit 202 in which antennas 206 that receive radio waves converged by the dielectric lens unit 201 and radio wave receiving elements 204 that detect the amount of radiation in the radio wave region are arranged in a matrix, and received by the reception array unit 202 A pass band control unit 205 that controls the frequency band, and a signal storage calculation unit 203 that performs storage of each radiation amount (radiation intensity signal) observed by the reception array unit 202 and intensity comparison processing. .

  FIG. 3 is a diagram showing a configuration of one radio wave receiving element 204 of the radio wave imaging unit 200 shown in FIG. In FIG. 3, electromagnetic waves radiated from a certain front direction are collected by a dielectric lens 201 and received by a radio wave receiving element 204. The radio wave receiving element 204 includes an antenna unit 206, a passband variable filter unit 209, a detection unit 207, and an amplification unit 208. The radio wave receiving element 204 is matched to the observation band, and outputs a radiation intensity signal of the matched observation band in the electromagnetic wave radiated from the object. The pass band variable filter unit 209 receives the pass band control signal from the pass band control unit 205 in FIG. 2 and changes the pass band to a low pass (pass band A), medium, as shown in FIG. Switching between band pass (pass band B) and high band pass (pass band C), or five pass bands from low pass band D to high pass band H as shown in FIG. The radiation intensity signal can be output in a time-sharing manner while switching to.

The passband variable filter unit 209 of this embodiment switches between two stages between the three-part passband variable filter 209a in FIG. 4A and the five-part passband variable filter 209b in FIG. It is configured to be possible.
4 (a) has a predetermined length via a PIN type diode DI1, DI2, DI3, DI4 as an example of a high-speed switching element in a transmission line of a dielectric line. Resonant lines DC1, DC2, and DC3 are incorporated. By making the resonance line length variable by combining ON and OFF of the diodes DI1 to DI4, as shown in FIG. 5A, the passband is the full passband (30 to 39 GHz), the passband A (30 to 33 GHz). ), Pass band B (33 to 36 GHz), and pass band C (36 to 39 GHz). In this case, in FIG. 4A, since the length of the resonant line is ½ of the center wavelength of the pass band, the length a (= 4 mm) of the resonant line DC1 is the center wavelength of 8 mm in the pass band C. The total length b (= 4.35 mm) of the resonance lines DC1 and DC2 is 1/2 of the center wavelength 8.7 mm of the passband B, and the total length of the resonance lines DC1 to DC3. The length c (= 4.76 mm) is approximately ½ of the center wavelength of the pass band A of 9.5 mm.

  As a result, the pass band of the pass band variable filter 209a becomes the full pass band by turning on the diodes DI1 to DI4 as shown in FIG. 4B, and the diodes DI2 and DI3 are turned on and the others are turned off. Is set to pass band A (resonant line length c), and diodes DI2 and DI4 are turned on and the others are turned off to pass band B (resonant line length b) and diodes DI3 and DI4 are turned on. By turning off the others, the passband C (resonant line length a) is obtained.

  Similarly, the five-pass variable-band filter 209b in FIG. 4C has a predetermined length via PIN diodes DI5, DI6, DI7, DI8, DI9, and DI10 in the transmission line of the dielectric line. Resonant lines DC5, DC6, DC7, DC8, and DC9 are incorporated. By making the resonance line length variable by combining ON and OFF of the diodes DI5 to DI10, as shown in FIG. 5B, the passband is the full passband (30 to 39 GHz) and the passband D (30 to 31). .8 GHz), passband E (31.8-33.6 GHz), passband F (33.6-35.4 GHz), passband G (35.4-37.2 GHz), and passband H (37. 2 to 39 GHz).

  In this case, in FIG. 4C, the length d (= 3.94 mm) of the resonance line DC5, the length e (= 4.13 mm) of the resonance line DC6, and the length f (= 4.35 mm) of the resonance line DC7. ), The length g (= 4.58 mm) of the resonant line DC8, and the length h (= 4.85 mm) of the resonant line DC9 are approximately ½ of the center wavelength 7.9 mm of the passband H and the passband, respectively. G center wavelength 8.3 mm 1/2, passband F center wavelength 8.7 mm 1/2, passband E center wavelength 9.1 mm 1/2, passband D center wavelength 9.7 mm 1/2.

  As a result, as shown in FIG. 4D, the pass band of the pass band variable filter 209b becomes the entire pass band by turning on the diodes DI5 to DI10, and the diodes DI9 and DI10 are turned off and the others are turned on. Is set to pass band D (resonant line length h), and diodes DI8 and DI9 are turned off and the others are turned on to pass band E (resonant line length g) and diodes DI7 and DI8 are turned off. By turning the others on, the pass band F (resonant line length f) is obtained, and by turning off the diodes DI6 and DI7 and turning others on, the pass band G (resonant line length e) is obtained. By turning off DI6 and turning on others, the passband H (resonant line length d) is obtained.

Hereinafter, radiation from an object will be described. Generally, radiant energy (electromagnetic waves) determined according to the temperature is radiated from the surface of an object at a certain temperature. Assuming that the emissivity of an object is ε and the energy radiated from a black body at a certain temperature is E ₀ , the energy E radiated from an object at a certain temperature is expressed by the equation (1).
E = ε × E ₀ (1)
The energy radiated from the black body can be calculated by Planck's radiation law, but it is known that the emissivity varies depending on the type of object, the surface state, and the measurement conditions (temperature, angle, wavelength). The emissivity of a substance is equal to the rate at which the substance absorbs radiation, and the following relationship holds between the reflectance and transmittance of the object.

“Reflectance” + “Absorption (radiation)” + “Transmittance” = 1 (2)
Since the object identification device 100 according to the present embodiment is a passive system that observes radiation from an object, the influence of the surface property of the object is small, and the physical property of the object can be identified from the amount of radiation observed. Moreover, it is also possible to cope with bad weather for vehicles. On the other hand, in active measurement devices such as radar devices that have been used in the past, the reflection component is detected for object detection, but the reflection component does not depend much on the physical properties of the object, It is difficult to specify the object from the detected reflection amount because the surface property of the object has a great influence.

  However, since object radiation is a minute signal, it is necessary to widen the observation frequency band (for example, about several GHz) in order to improve sensitivity. However, when the observation frequency band is widened, there may be cases where other wireless devices use radio waves within the observation frequency band. The radio signal emitted by such a wireless device is considerably stronger than the amount of radiation from a normal object, so as it is, an object with a large amount of radiation (high emissivity, high temperature) is caused by interference of the radio signal from the wireless device. It is misunderstood that (object) exists.

  In the present embodiment, as a countermeasure against mixing of radio signals from wireless devices accompanying the widening of the observation frequency band as described above, the passband variable filter 209a or 209b in FIG. 4 (a) or FIG. 4 (c) is used. Is used to divide the observation frequency band into three communication bands A to C or five communication bands D to H, detect a communication band in which radio signals transmitted from other wireless devices are observed, and the communication band Object identification is performed except for. This makes it possible to adapt to changes in various radio wave environments when the object identification device 100 is mounted on a moving means such as a vehicle.

  Hereinafter, the interference countermeasure operation in the case where there is a wireless device that outputs a radio signal within the observation frequency band of the radio wave imaging unit 200 illustrated in FIG. 2 will be described with reference to FIGS. This operation is controlled by the signal storage calculation unit 203 and the communication band control unit 205, and is executed in parallel in a plurality of radio wave receiving elements 204 arranged in a matrix constituting the reception array unit 202 in the radio wave imaging unit 200. Is done.

  First, the control signal for dividing the observation frequency band into three parts is input from the passband control part 205 to the passband variable filter part 209 of the radio wave imaging part 200, so that the antenna of the radio wave receiving element 204 shown in FIG. The radiation amount signal from the unit 206 is supplied to the passband variable filter 209a in FIG. 4A, and the observation frequency band is divided into the three passbands A to C in FIG. 5A in time series. The divided radiation amount signals for each communication band are output to the signal storage calculation unit 203 in FIG. 2 in time series. The signal storage calculation unit 203 compares the radiation intensity of the observation band divided for each radio wave receiving element 204 and determines whether there is a radio signal other than object radiation depending on whether the intensity has changed. ing.

  FIG. 6 shows an example of signal detection in band division. Case 1 in FIG. 6 is a signal example when there is no interfering object. In the case of object radiation, since there is no significant change in radiation intensity with a frequency change of about several GHz, the passing areas A, B, and C show similar values. At this time, as a detection signal of the radio wave receiving element 204, a value obtained by adding the observation values (intensity signals) of the passage areas A, B, and C is output to the radiation intensity image generation unit 300 in FIG. Is done.

  However, when the radio signal of the wireless device exists in the observation frequency band and the radio device performs the radio wave transmission operation, the observed value for each pass band varies as shown in cases 2 to 4 in FIG. Occur. This is because the use frequency band of the wireless device is regulated by the Radio Law, and the signal output operation is performed in a frequency region with a bandwidth of 1 GHz or less. For example, when there is a wireless device that operates in the pass band A, a greater radiation intensity is observed in the pass band A than in the other pass bands B and C as shown in Case 2 of FIG. By comparing the radiation amount observation value for each pass band, it can be determined that the radio signal from other wireless devices other than the object radiation has an influence in the pass band A by the majority rule.

  In this case, since the observed value of the pass band A is an inappropriate signal for identifying the object, the observed value of the pass bands B and C excluding this is used as the object radiation amount, and the bandwidth is In consideration of the fact that it is 2/3, the amplitude level is normalized and output to the radiation intensity image generation unit 300 in FIG. As an example of the normalization, the sum of the observation values of the passbands B and C is multiplied by 3/2 to make the average value equal to the observation value from the radio wave receiving element 204 subjected to other normal processing. It is. Further, case 3 in FIG. 6 is an example of signal observation when a radio signal other than object radiation exists in pass band B and case 4 in pass band C. Similarly, there are radio signals other than object radiation. The passbands B and C are excluded and the object radiation intensity is output to the subsequent stage.

  In the example of FIG. 6, a corresponding example is shown in the case where the observation frequency band is divided into three and there is one kind of interfering object such as a wireless device. However, when there are two or more types of wireless devices in different bands, as shown in examples 5 to 7 in FIG. 7, the passband in which the radio signal is present cannot be specified, so the observation frequency band is further subdivided. In this manner, the control of the passband variable filter unit 209 is changed.

  That is, Case 5 in FIG. 7 is an example in which an interference object exists in the passbands A and B and the observed value becomes large, and Case 6 in FIG. 7 has an interference object in the passband A. This is an example in which the observed value becomes large, and in the pass band B, the observed value is medium and it is unknown whether it is due to an interfering object. In these cases, if the observation values of the two pass bands A and B are thinned out and only the observation value of the pass band C is used, the band becomes too narrow and a radiation intensity signal that can identify an object is obtained. There is a risk of not.

  On the other hand, Example 7 in FIG. 7 is an example in which the observation values of all the pass bands A to C are large. This is because radio signals from different interfering objects are mixed in all the pass bands A to C. For example, it cannot be determined whether or not there is an observation target object having a high emissivity ε in the equation (1). Therefore, even in the case 7, when the observation frequency band is further subdivided and the observation value is large in all the passbands after the subdivision, the observation value is regarded as a radiation intensity signal from the object to be observed. Normal processing (using the sum of the observation values of all passbands) is performed. On the other hand, in the pass band after subdivision, when there are fewer bands with larger observed values due to majority vote, processing is performed by thinning out the observed values in the band with larger observed values.

  In this embodiment, in order to further subdivide the observation frequency band, the passband control unit 205 in FIG. 2 changes the passband variable filter unit 209 in FIG. A control signal is output so as to switch to the passband variable filter 209b. In response to this, the radiation amount signal from the antenna unit 206 of the radio wave receiving element 204 in FIG. 3 is supplied to the passband variable filter 209b in FIG. 4C, and the observation frequency band is five in FIG. It is divided into pass bands D to H in time series. The divided radiation amount signals for each communication band are output to the signal storage calculation unit 203 in FIG. 2 in time series. The signal storage operation unit 203 compares the radiant intensities of the divided communication bands D to H, and, as an example, when the number of observation bands with a large observation value is smaller than the number of communication bands with a small observation value by the majority rule. Then, it is determined that there is a radio signal other than the object radiation, and the observation band having a large observed value is excluded and observation is performed.

  Specifically, Case 6 in FIG. 7 shows a case where the radio signal of the wireless device is present in the band 5A that covers the boundary between the pass bands A and B, as shown in FIG. In this case, by changing the observation frequency band from three to five in FIG. 5B, the band 5A of the wireless device enters the pass band E, and only the observed value of the pass band E increases. Therefore, by decimating only the observation value of the pass band E, the radiation amount from the object can be detected in a relatively wide band.

  Next, an example of the operation of the object identification process by the object identification device 100 of the present embodiment will be described with reference to the flowchart of FIG. When the operation is started, in step S1, each radio wave receiving element 204 in the receiving array unit 202 of the radio wave imaging unit 200 shown in FIG. 2 has the three divided pass bands A, B, and C in FIG. The amount of radiation (radiant intensity) from the front of the vehicle is observed and output to the signal storage calculation unit 203. In the next step S2, the signal storage calculation unit 203 compares the radiation intensity obtained in step S1 for each pass band, and if it is determined that the observed values of the divided bands are substantially equal, the step S3 If it is determined that the observed value of one band is significantly larger than the observed value of the other band, the process proceeds to step S4, and the observed values of two or more bands are significantly larger (or one of the observed values is If it is medium, the process proceeds to step S5.

  In step S3, the observation values of all the bands are added and output to the radiation intensity image generation unit 300 in FIG. 1A together with the array number of the radio wave receiving element 204, and the process proceeds to step S6. In step S4, the observed values of the bands other than the band in which a remarkably large value is observed are added, the intensity change due to the band becoming 2/3 is normalized, and the radiation intensity image together with the array number of the radio wave receiving element 204 is obtained. It outputs to the production | generation part 300 and progresses to step S6. In step S5, the number of divided bands is set to 5 in FIG. 5B, and the process returns to step S1.

  In step S6, the radiant intensity image generation unit 300 generates a radiant intensity image based on the radiant intensity value output from the signal storage calculation unit 203 and the array number of the radio wave receiving element, and groups spatial regions for each radiant intensity. And output to the object recognition processing unit 400. In the next step S <b> 7, the object recognition processing unit 400 identifies an object from the radiation intensity image output from the radiation intensity image generation unit 300 and the spatial region information grouped for each radiation intensity. In the next step S8, the object recognition result is output to the vehicle control device 500 (vehicle CPU) in FIG. 1A, and the operation is terminated.

In addition, in step S2 after increasing the number of passband divisions in step S5, when the number of passbands having a large observation value increases again, as an example, the region of the image corresponding to the radio wave receiving element 204 May display luminance or color indicating the presence of the wireless device.
The object identification device 100 according to the present embodiment has the following operational effects.

  (1) The object identification device 100 includes a radio wave imaging unit 200 having a plurality of radio wave receiving elements 204 that detect the amount of radiation in a radio wave region radiated from an object, and detection signals (radiation) from the plurality of radio wave receiving elements 204. A radiation intensity image generation unit 300 that extracts information on the spatial position and shape of the object from the intensity signal), and the observation frequency band of the detection signal of the radio wave receiving element 204 is set to a plurality of narrower pass bands A to C or D to H ( Detection by comparing the intensity of the detection signal of the radio wave receiving element 204 for each of a plurality of pass bands A to C or D to H divided in such a manner. Determine whether there is a passband in which radio signals other than radiation from the target object are mixed, and observe frequencies other than the passband in which the radio signals are determined to be mixed And a signal storage operation unit 203 which processes the detected signal of the wave receiving element 204 of the band on the radiation intensity image generation unit 300.

  Therefore, in the passband showing a remarkably high radiation intensity, it is determined that there is a wireless device that transmits a radio signal, and by performing object identification processing using the radiation intensity of the other passband, the wireless device, etc. Therefore, it is possible to accurately detect (observe) the amount of radiation from an object without being disturbed by a radio signal from the object. As a result, it is possible to cope with various radio wave environments such as a traveling environment of the vehicle, and it becomes possible to identify the radiation object stably.

(2) In the object identification device 100, the passband variable filter unit 209 divides the observation frequency band into at least three passbands AC. Therefore, it can be determined, for example, by the majority rule whether or not a radio signal from a wireless device or the like is present in the pass band.
(3) The radio wave receiving element 204 includes an antenna unit 206 that receives an amount of radiation in the radio wave region, and a detection unit 207 that detects a detection signal of the antenna unit 206. The passband variable filter unit 209 includes the antenna unit 206. And a detection unit 207, and passband variable filters 209a and 209b that pass a signal in at least one of the passbands obtained by dividing the observation frequency band into three or five substantially evenly. .

Thus, by making the bandwidths of the plurality of passbands substantially equal, it is possible to accurately compare the intensity of the observed radiation values for determining the presence or absence of interference from radio signals from other wireless devices.
(4) The passband variable filter unit 209 can divide the observation frequency band into two stages of passbands A to C or D to H having different numbers of divisions, and the signal storage operation unit 203 includes the radio signal mixed. Then, when there are a plurality of determined passbands, the number of divided observation frequency bands by the passband variable filter unit 209 is increased.

  Accordingly, for example, as shown in FIG. 5 (a), when the frequency band 5A of the radio signal in which interference occurs exists over a plurality of divided pass bands A and B, the number of divisions is increased, As shown in FIG. 5B, by adjusting the frequency band 5A of the radio signal in which interference occurs within one pass band E, more effective interference band removal can be realized. As a result, the proportion of passbands that can be used effectively increases, and the amount of radiation from the object can be detected with high accuracy.

(5) Since the vehicle MB (see FIG. 1) includes the passive object identification device 100 in the radio wave region, it is possible to identify an object that cannot be identified by a normal infrared camera or the like.
In the first embodiment, the example in which the number of band divisions is made variable and the detection signal of each pass band is observed in time series has been described. However, when the radio wave usage environment is known and the number of divisions of the observation frequency band of the detection signal from the antenna unit 206 in FIG. 3 can be fixed, as shown by the radio wave receiving element 204A in FIG. The detection signal from the power is distributed using the power distributor 210, and the band-pass filters 211, 212, 213, the detection unit 207, and the amplification unit 208 are provided by the number of band divisions, and output simultaneously to compare and calculate the radiation intensity. It is also possible to do.

  FIG. 9 shows a case where the number of divisions of the observation frequency band is fixed to three, and the band-pass filters 211, 212, and 213 pass the signals in the pass bands A, B, and C of FIG. , A low-pass filter, a band-pass filter, and a high-pass filter. According to this configuration, since a plurality of passband signals can be processed in parallel, the processing time can be shortened.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
In the first embodiment, the radio wave imaging unit 200 includes the passband variable filter unit 209 that controls the passband. However, the second embodiment uses a unit that controls the stopband instead. The same effect is obtained. Hereinafter, in FIGS. 10 and 11, the same reference numerals are given to the portions corresponding to FIGS. 1A and 3, and the detailed description thereof will be omitted. Further, in the flowcharts of FIGS. 14 and 15, steps corresponding to those in the flowchart of FIG. 8 are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 10 shows a configuration of the object identification device 100 of the present embodiment. The object identification device 100 of FIG. 10 is different from the object identification device 100 of the first embodiment of FIG. Instead, a radio wave receiving element 204B is used, and a cutoff band control unit 215 is provided instead of the pass band control unit 205 of FIG.
FIG. 11 shows the configuration of the radio wave receiving element 204B in FIG. 10. In FIG. 11, signals in a plurality of predetermined frequency bands (cut-off band: also referred to as a removal band) are provided between the antenna unit 206 and the detection unit 207. A stop band variable filter unit 214 capable of blocking is provided, and a stop band (removal band) of the stop band variable filter unit 214 is controlled by a stop band control signal from the stop band control unit 215 of FIG. Also in the present embodiment, the stopband variable filter unit 214 can switch between a stopband with a first division number (for example, 3 divisions) and a stopband with a second division number (for example, 5 divisions). .

12 shows three stop bands D (36 to 39 GHz), stop band E (33 to 36 GHz), and stop band F (30 to 33 GHz) set in time series by the stop band variable filter unit 214 of FIG. Show. Note that the bands D to F in FIGS. 12 and 13 are used in a different meaning from the bands D to F in FIGS. 4 (d) and 5 (b).
As shown in FIG. 12, when the stop band is sequentially changed to the stop band D, the stop band E, and the stop band F, the pass band at that time is the pass band D (30 to 36 GHz) and the pass bands E and E ′ (30 To 33 GHz, 36 to 39 GHz) and pass band F (33 to 39 GHz). The two pass bands E and E ′ are hereinafter simply referred to as pass band E. The intensity comparison results of the observed values of the radiation intensity signals in these pass bands D, E, and F are shown in Case 1 to Case 4 in FIG. Bands D to F in FIG. 13 represent pass bands D to F in FIG. 12.

  Case 1 in FIG. 13 is a case where there is no interference from the wireless device and normal processing can be performed using signals in the entire pass band. Case 2 is a result of interference occurring in the pass band D. This is a case in which the observation value becomes remarkably large in the band E, and a radiation image is generated using the observation value in the pass band F. Case 3 is a case where the observed value in the passband D becomes significantly large as a result of interference in the passband F, and a radiation image is generated using the observed value in the passband E. Case 4 is As a result of interference occurring in the pass band E, the observed value in the pass band F becomes significantly large, and a radiation image is generated using the observed value in the pass band D.

  Unlike the case of controlling the passband as shown in FIG. 6, when the stopband is controlled as in the present embodiment, as shown in FIG. 13, it is divided into one divided passband (for example, passband D). It can be seen that when radio signals from other wireless devices are mixed, two pass bands (for example, pass bands D and E or D and F) are affected. In this case, the object identification processing is performed using the radiation amount observation value of another pass band (for example, pass band F or E) in which no interference occurs.

The processing method of the present embodiment has an advantage that the process of detecting the presence or absence of interference can be simplified when the use frequency band of the wireless device to be blocked is known in advance.
If the wireless device to be cut off is a fixed station and the installation location is known, information on the installation location and frequency of use of the wireless device is recorded in the map data file 601 of the navigation system 600 in FIG. May be. At this time, when a vehicle equipped with the object identification device 100 of FIG. 10 enters a range (area) where interference from a wireless device recorded in the map data file 601 is expected, the information on the used frequency is cut off. This is supplied to the band control unit 215, and the cutoff band control unit 215 detects the presence or absence of interference by blocking a frequency band (any one of the cutoff bands D to F in FIG. 12) in which interference will occur in advance. Processing can be omitted.

  Next, an example of the object identification processing operation by the object identification device 100 of the second embodiment of FIG. 10 will be described with reference to the flowchart of FIG. After starting the observation operation, in step S10, the radio wave receiving element 204B in FIG. 10 observes the radiation amount while changing the cutoff band, and in step S11, compares the observed radiation intensity values for each cutoff band. If the observed values when using each cut-off band are substantially the same, the process proceeds to step S12, the average value of the observed values is normalized and output to the radiation intensity image generating unit 300 in FIG. 10, and the process proceeds to step S6. In step S11, when a significantly large observation value is measured when two cut-off regions are used in the observed radiation dose observation value, the process proceeds to step S13, and other than a significantly large observation value (a small radiation dose is observed). Normalization values) are normalized and output to the radiation intensity image generation unit 300, and the process proceeds to step S6. In step S11, if one of the observed radiation dose observation values is significantly larger than the other observation values, it is determined that the cutoff band does not match the band of the radio signal from the wireless device. Proceeding to S14, the cut-off band is narrowed to increase the number of divisions by one, and the process returns to step S10 to perform remeasurement.

The other operations are the same as those in the flowchart shown in FIG. 8, and the radiation amount from the object can be accurately observed without being disturbed by the radio signal from the wireless device or the like.
Next, with reference to a flowchart of FIG. 15, an example of an operation when performing object identification processing using the map data file 601 of FIG. 10 in the present embodiment will be described. In FIG. 15, steps that perform the same operations as those in the flowchart of FIG. 14 are given the same reference numerals, and detailed descriptions thereof are omitted. After starting the observation operation, in step S21 in FIG. 15, the navigation system 600 in FIG. 10 acquires position information of the vehicle on which the object identification device 100 is mounted from a GPS system (not shown) or the like. In the next step S22, the navigation system 600 compares the current position of the vehicle with the location information of the wireless device recorded in the map data file 601, and determines whether or not the vehicle is in the communication area of the wireless device. to decide. If the communication area is entered, the process proceeds to step S23. If the communication area is not entered, the process proceeds from step S10 to S11, and the radiation amount from the object is observed as in FIG.

In step S23, the navigation system 600 outputs information on the used frequency of the wireless device to the cutoff band control unit 215 of FIG. 10, and in response to this, the cutoff band control unit 215 causes the radio wave receiving element 204B to The cut-off band is controlled so as to cut off the frequency that interferes with the use frequency, the radiation amount is observed, and the process proceeds to step S6.
Further, when the process proceeds from step S11 to step S13 in FIG. 15, since a new wireless device is detected, an observation value in a band where a small radiation amount is observed is output to the radiation intensity image generation unit 300 (following this). The operation after step S6 is executed), and the process proceeds to step S24, where two pass bands where a significantly large radiation amount is observed overlap (that is, a block where interference due to radio signals from the wireless device is observed) Band) information is output to the navigation system 600 from the signal storage calculation unit 203 of FIG. In response to this, the navigation system 600 records the cut-off band information and the current vehicle position information in the map data file 601. Therefore, after that, when the vehicle passes the same route, in step S22 in FIG. 15, since it can be recognized that the radio wave transmission range of the known wireless device, the frequency band that interferes with the wireless device is blocked in advance. By doing so, the operation of detecting the wireless device can be omitted.

According to the object identification device of the second embodiment, in addition to the functions and effects of the first embodiment, the following functions and effects are achieved.
(1) As shown in FIG. 11, the cutoff band variable filter unit 214 is disposed between the antenna unit 206 and the detection unit 207, and is arbitrarily selected from the bands obtained by dividing the observation frequency band almost equally. Block one band signal.

Therefore, by making the bandwidth of the cut-off band almost equal, the bandwidth of the passband can be made almost equal, and the intensity comparison of the radiation observation values to determine the presence or absence of interference due to radio signals from other wireless devices Can be performed accurately.
(2) When the location of the wireless device existing in the observation range and the use frequency band are already known using the map data file 601 of the navigation system 600, the cutoff band is set to the use frequency of the wireless device. The bandwidth is set. Thereby, the process which judges the presence or absence of interference can be simplified.

(3) If it is determined that there is interference from a new wireless device not recorded in the map data file 601, the location where the interference has occurred and the frequency band used by the wireless device are recorded in the map data file 601. Thereby, it becomes possible to effectively remove the interference of radio signal by the wireless device thereafter.
In the above embodiment, the observation frequency band of the radio wave imaging unit 200 is a 30 to 40 GHz band that is less affected by atmospheric propagation attenuation in order to perform object observation up to a longer distance outdoors. The band may be set to other 90 to 100 GHz band.

Further, the object identification device of the present invention can be applied not only to vehicles but also to ships, aircrafts, etc., and can also be applied to building monitoring devices, security use person identification devices, and the like.
The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  The correspondence between the main components of the present invention and the embodiment is as follows. That is, the band dividing unit corresponds to the passband variable filter unit 209 or the stopband variable filter unit 214, the determination unit corresponds to the signal storage calculation unit 203, and the image processing unit corresponds to the radiation intensity image generation unit 300.

  In addition, the above description is an example to the last, Comprising: When interpreting invention, it is not limited or restrained at all by the correspondence of the description matter of said embodiment, and the description matter of a claim.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram (a) showing an object identification device according to a first embodiment of the present invention, and a perspective view (b) showing a vehicle equipped with the object identification device. It is a figure which shows the structure of the receiving array part 202 grade | etc., In the electromagnetic wave imaging part 200 shown to Fig.1 (a). It is a figure which shows the structure of the electromagnetic wave receiving element 204 which comprises the receiving array part 202 of FIG. As a diagram showing the configuration and passband of the passband variable filter unit 209 shown in FIG. 3, a diagram showing a configuration of a three-part passband variable filter 209a (a), a diagram showing a three-part passband (b), FIG. 6C is a diagram showing the configuration of a five-divided passband variable filter 209b, and FIG. It is a figure (a) which shows time change of a pass band when an observation frequency band is divided into three, and a figure (b) which shows time change of a pass band when an observation frequency band is divided into five. In 1st Embodiment, when one kind of interference object exists in an observation frequency band, it is a figure where it uses for description of the signal processing in each pass band. In 1st Embodiment, when two or more types of interfering objects exist in an observation frequency band, it is a figure where it uses for description of the signal processing in each pass band. It is a flowchart which shows the process sequence of the object identification apparatus in 1st Embodiment. It is a figure which shows the other structural example of the electromagnetic wave receiving element in 1st Embodiment. It is a block diagram which shows the object identification device by 2nd Embodiment. It is a figure which shows the structure of the electromagnetic wave receiving element 204B shown in FIG. It is a figure which shows the time change of a pass band at the time of dividing | segmenting an observation frequency band into three stop bands in 2nd Embodiment. In 2nd Embodiment, when one kind of interference object exists in an observation frequency band, it is a figure where it uses for description of the signal processing in each band. It is a flowchart which shows the process sequence of the object identification apparatus in 2nd Embodiment. In 2nd Embodiment, it is a flowchart which shows the process sequence using the map data file of an object identification device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Object identification apparatus 200 Radio wave imaging part 201 Dielectric lens part 202 Reception array part 203 Signal storage calculating part 204,204A, 204B Radio wave receiving element 205 Pass band control part 206 Reception antenna 207 Detection part 209 Pass band variable filter part 214 Cut off band Variable filter unit 215 Stop band control unit 300 Radiation intensity image generation unit 400 Object recognition processing unit 500 Vehicle control device 600 Navigation system

Claims (10)

Band division means for receiving radio waves radiated from the detection target object and outputting a plurality of band-specific detection signals corresponding to a plurality of radiation amount observation bands,
By comparing the amount of radio wave radiation represented by the plurality of band-specific detection signals, it is determined whether or not an external radio signal radiated from other than the detection target object is mixed in any of the band-specific detection signals. Determination means to perform,
When it is determined by the determination means that the external radio signal is mixed, the band-specific detection signal in which the external radio signal is mixed is excluded from the plurality of band-specific detection signals. When the image based on the radiation intensity of the detection target object is generated, and when the determination unit determines that the external radio signal is not mixed, the detection target is used by using all of the plurality of band-specific detection signals. Image processing means for generating an image based on the radiation intensity of the object;
An object identification device comprising: The object identification device according to claim 1,
The band dividing means outputs a plurality of band-specific detection signals corresponding to each of the plurality of radiation amount observation bands by sequentially setting a predetermined radiation amount observation band in time series. apparatus. In the object identification device according to claim 1 or 2,
The band dividing unit is configured to change the number of radiation amount observation bands when the determination unit determines that the external radio signal is mixed. The object identification device according to claim 1, further comprising:
Receiving a radio wave radiated from the object to be detected, and comprising a distribution means for distributing the received power of the radio wave to a plurality of systems,
The object discriminating apparatus characterized in that the plurality of band dividing means for inputting the respective system outputs from the distributing means simultaneously output specific detection signals for specific bands respectively. In the object identification device according to any one of claims 1 to 3 ,
The band dividing unit receives an electric wave radiated from the detection target object using a plurality of antennas arranged in an array. In the object identification device according to any one of claims 1 to 5,
The band dividing means uses a band-pass filter or a band elimination filter when outputting a plurality of band-specific detection signals corresponding to the plurality of radiation amount observation bands, respectively. In the object identification device according to any one of claims 1 to 6,
The image processing means identifies the detection target object by grouping a spatial region for each predetermined radiation intensity in the generated image. In the vehicle provided with the object identification device according to any one of claims 1 to 7,
A map database in which position information of wireless devices that generate radio waves that interfere with specific observation bands in the plurality of radiation amount observation bands is recorded;
When it is determined that the vehicle has entered a geographical area that interferes with radio waves generated by the wireless device based on the map database, the band dividing unit calculates the specific observation band from the plurality of radiation amount observation bands. A vehicle which is removed and outputs the band-specific detection signal. The vehicle according to claim 8, further comprising:
When there is a radio wave that interferes with any one of the plurality of radiation amount observation bands, there is provided means for writing geographical position information and observation band information in which the radio wave interference occurs in the map database. Vehicle. Receiving radio waves radiated from the object to be detected, and outputting a plurality of band-specific detection signals corresponding to each of a plurality of radiation amount observation bands;
By comparing the amount of radio wave radiation represented by the plurality of band-specific detection signals, it is determined whether or not an external radio signal radiated from other than the detection target object is mixed in any of the band-specific detection signals. And steps to
When it is determined that the external radio signal is mixed, by excluding the band-specific detection signal in which the external radio signal is mixed from the plurality of band-specific detection signals, When an image based on radiation intensity is generated, and on the other hand, when it is determined that the external radio signal is not mixed, an image based on the radiation intensity of the detection target object is obtained using all of the plurality of band-specific detection signals. Generating step;
An object identification method comprising:

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