JP6962253B2 - Radio wave sensor, deviation measurement method and deviation measurement program - Google Patents

Description

The present invention relates to a radio wave sensor, a deviation measuring method and a deviation measuring program.

In recent years, in-vehicle radars used for collision prevention of automobiles have been developed. For example, Japanese Patent Application Laid-Open No. 2006-308542 (Patent Document 1) discloses the following electronic scanning millimeter-wave radar apparatus. That is, the electronic scanning millimeter-wave radar device Fourier transforms the digitized beat signal and generates a beam signal at a predetermined pitch angle based on the Fourier transform. Next, the electron scanning millimeter-wave radar device detects the direction and distance of the object from the generated beam signal. Then, the electronic scanning millimeter-wave radar device detects whether or not there are a plurality of objects at substantially the same distance in the beat signal corresponding to each Fourier transformed receiving antenna based on the detected object's orientation and distance. Then, the beat signal is separated.

Japanese Unexamined Patent Publication No. 2006-308542

Koji Quarter, 2 outsiders, "Expanding Millimeter Wave Technology Application", Shimada Rika Giho, 2011, No. 21, P.M. 37-48 Takayuki Inaba, Tetsuro Kirimoto, "In-Vehicle Millimeter Wave Radar", Automotive Technology, February 2010, Vol. 64, No. 2, P.M. 74-79 Eugin Hyun, 2 outsiders, "A Pedestrian Detection Scene Using a Coherent Phase Difference Method Based on 2D Range-Doppler FMCW Radar", Volume 16, Year 16 124 Nobuyoshi Kikuma, "Adaptive Signal Processing by Array Antenna", First Edition, Science and Technology Publishing Co., Ltd., November 1998, p. 181 and p. 194

For example, in the vehicle-mounted radio wave sensor described in Patent Document 1, the detection target area of the object is set based on the relative angle and distance with respect to the radio wave sensor.

Further, a radio wave sensor provided above the road for detecting an object such as a vehicle traveling on the road is known. Such a radio wave sensor is installed with its orientation adjusted so that it can detect an object in the target area.

However, there is a possibility that the direction of the radio wave sensor may be deviated due to the influence of the vibration of the support column supporting the road or the radio wave sensor, strong wind, etc., and the object may not be detected or falsely detected in the target area.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a radio wave sensor, a deviation measurement method, and a deviation measurement program capable of easily measuring the deviation of the orientation of the radio wave sensor. be.

(1) In order to solve the above problems, the radio wave sensor according to a certain aspect of the present invention is based on a transmitting unit for transmitting radio waves, a receiving unit for receiving radio waves, and radio waves received by the receiving unit. A detection unit that detects an object, an area calculation unit that calculates a detectable area of the radio wave sensor based on a plurality of detection results of the detection unit, and a reference area that is a detection area held by the radio wave sensor. A deviation calculation unit for calculating a deviation from the detectable area calculated by the area calculation unit is provided.

(6) In order to solve the above problems, the deviation measuring method according to a certain aspect of the present invention is a deviation measuring method in a radio wave sensor, which is a step of transmitting a radio wave, a step of receiving a radio wave, and a received radio wave. Based on, a step of detecting an object, a step of calculating a detectable area of the radio wave sensor based on a plurality of detection results, and a reference area which is a detection area held by the radio wave sensor were calculated. It includes a step of calculating the deviation from the detectable area.

(7) In order to solve the above problems, the deviation measurement program according to a certain aspect of the present invention is a deviation measurement program used in a radio wave sensor, and is a computer, a transmission unit for transmitting radio waves, and a transmission unit for receiving radio waves. A receiving unit, a detecting unit that detects an object based on the radio waves received by the receiving unit, and an area calculating unit that calculates a detectable area of the radio wave sensor based on a plurality of detection results of the detecting unit. This is a program for functioning as a deviation calculation unit for calculating the deviation between the reference area, which is the detection area held by the radio wave sensor, and the detectable area calculated by the area calculation unit.

The present invention can be realized not only as a radio wave sensor provided with such a characteristic processing unit, but also as a semiconductor integrated circuit that realizes a part or all of the radio wave sensor, or as a system provided with a radio wave sensor. Can be done.

According to the present invention, the deviation of the orientation of the radio wave sensor can be easily measured.

FIG. 1 is a diagram showing an installation example of a radio wave sensor according to an embodiment of the present invention. FIG. 2 is a diagram showing a state viewed from above the radio wave sensor in the installation example of the radio wave sensor according to the embodiment of the present invention. FIG. 3 is a diagram showing a configuration of a radio wave sensor according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of each waveform of the transmission wave and the difference signal generated by the transmission unit and the difference signal generation unit in the radio wave sensor according to the embodiment of the present invention. FIG. 5 is a table showing an example of a detection result by the signal processing unit in the radio wave sensor according to the embodiment of the present invention. FIG. 6 is a diagram showing a detailed configuration of a control unit in the radio wave sensor according to the embodiment of the present invention. FIG. 7 is a diagram showing an example of a detectable area calculated by an area calculation unit in the radio wave sensor according to the embodiment of the present invention. FIG. 8 is a diagram (Example 1) for explaining a method of calculating the pan angle deviation by the deviation calculation unit in the radio wave sensor according to the embodiment of the present invention. FIG. 9 is a diagram (Example 2) for explaining a method of calculating the pan angle deviation by the deviation calculation unit in the radio wave sensor according to the embodiment of the present invention. It is a figure seen from the side of the radio wave sensor in the installation example of the radio wave sensor for demonstrating the calculation method of the tilt angle by the deviation calculation part in the radio wave sensor which concerns on embodiment of this invention. FIG. 11 is a diagram showing a detectable area for explaining a method of calculating a tilt angle deviation by a deviation calculation unit in the radio wave sensor according to the embodiment of the present invention. FIG. 12 is a flowchart defining an operation procedure when the radio wave sensor according to the embodiment of the present invention calculates and corrects its own deviation.

First, the contents of the embodiments of the present invention will be listed and described.

(1) The radio wave sensor according to the embodiment of the present invention includes a transmission unit that transmits radio waves, a reception unit that receives radio waves, and a detection unit that detects an object based on the radio waves received by the reception unit. , Calculated by the area calculation unit that calculates the detectable area of the radio wave sensor based on the plurality of detection results of the detection unit, the reference area that is the detection area held by the radio wave sensor, and the area calculation unit. It also includes a deviation calculation unit that calculates the deviation from the detectable area.

In this way, by calculating the deviation between the reference area and the detectable area based on the plurality of detection results of the object, the deviation is recognized from the calculation result without manually measuring the deviation of the direction of the radio wave sensor. be able to. Therefore, the deviation of the direction of the radio wave sensor can be easily measured.

(2) Preferably, the deviation calculation unit calculates the deviation of the pan angle of the radio wave sensor based on the deviation of the angle between the reference area and the detectable area.

In this way, with the configuration of calculating the deviation of the angle with respect to the reference area, the deviation of the pan angle of the radio wave sensor can be measured by a simple calculation process.

(3) Preferably, the deviation calculation unit calculates the deviation of the tilt angle of the radio wave sensor based on the difference in the distance between the reference area and the detectable area with respect to the radio wave sensor.

With such a configuration, for example, the tilt angle of the radio wave sensor can be calculated by a simple calculation process for calculating the difference between the distance from the radio wave sensor to the end of the reference area and the distance from the radio wave sensor to the end of the detectable area. The deviation can be measured.

(4) More preferably, the deviation calculation unit includes the reference area and the detectable area based on the traveling direction of the object in the detectable area detected by the detecting unit and the reference area. Calculate the deviation of the angle.

With such a configuration, for example, even when the detectable area has a complicated shape, the difference in angle between the reference area and the detectable area is determined based on the traveling direction of the object in the detectable area. Can be calculated.

(5) Preferably, the transmitting unit includes a plurality of antenna elements, and the radio wave sensor further includes a position between radio waves radiated from the antenna element based on the deviation calculated by the deviation calculating unit. A correction unit for correcting the deviation by adjusting the phase difference is provided.

With such a configuration, it is possible to correct the deviation of the direction of the radio wave sensor without human intervention and prevent the non-detection or false detection of the object.

(6) The deviation measuring method according to the embodiment of the present invention is a deviation measuring method in a radio wave sensor, and detects an object based on a step of transmitting a radio wave, a step of receiving a radio wave, and a received radio wave. Step to calculate, the step of calculating the detectable area of the radio wave sensor based on a plurality of detection results, the deviation between the reference area which is the detection area held by the radio wave sensor and the calculated detectable area. Includes steps to calculate.

In this way, by the method of calculating the deviation between the reference area and the detectable area based on the plurality of detection results of the object, the deviation is recognized from the calculation result without manually measuring the deviation of the direction of the radio wave sensor. be able to. Therefore, the deviation of the direction of the radio wave sensor can be easily measured.

(7) The deviation measuring program according to the embodiment of the present invention is a deviation measuring program used in a radio wave sensor, and is a computer, a transmitting unit for transmitting radio waves, a receiving unit for receiving radio waves, and the receiving unit. The radio wave sensor holds a detection unit that detects an object based on the radio wave received by the radio wave sensor, an area calculation unit that calculates a detectable area of the radio wave sensor based on a plurality of detection results of the detection unit, and the radio wave sensor. This is a program for functioning as a deviation calculation unit for calculating the deviation between the reference area, which is the detection area, and the detectable area calculated by the area calculation unit.

In this way, by calculating the deviation between the reference area and the detectable area based on the plurality of detection results of the object, the deviation is recognized from the calculation result without manually measuring the deviation of the direction of the radio wave sensor. be able to. Therefore, the deviation of the direction of the radio wave sensor can be easily measured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated. In addition, at least a part of the embodiments described below may be arbitrarily combined.

<Configuration and basic operation>
[Overview of radio wave sensor]
FIG. 1 is a diagram showing an installation example of a radio wave sensor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which the radio wave sensor is viewed from above in the installation example of the radio wave sensor according to the embodiment of the present invention.

With reference to FIGS. 1 and 2, the radio wave sensor 101 is, for example, a radar that transmits radio waves such as millimeter waves, and is provided above an intersection or a straight road. In this example, the radio wave sensor 101 is provided at a position at a height Hr from the road Rd, and transmits radio waves to the upstream side of the road Rd, which is a straight road. The road Rd is a general road. The road Rd may be an expressway or the like.

The direction of the radio wave sensor 101 is initially set so that the transmitted radio wave reaches, for example, the reference area As, which is a predetermined detection area. The reference area As is an area that serves as a reference for the detection area of the radio wave sensor 101, and includes, for example, a part of the road Rd and is located on the upstream side of the road Rd with respect to the radio wave sensor 101. The radio wave sensor 101 holds reference area information indicating the reference area As.

Here, the sensor coordinate system is defined as follows. That is, the sensor coordinate system is, for example, a coordinate system represented by Cartesian coordinates having X, Y, and Z as components, and the radio wave sensor 101 is located at the origin. The direction of the Z axis is perpendicular to the X and Y axes and points vertically upward.

The direction of the X-axis is the direction from directly in front to directly behind the reference area As side of the radio wave sensor 101, that is, the traveling direction of the vehicle 181 as a result of the radio wave sensor 101 detecting the direction of the object. The direction of the Y-axis is the direction from directly behind the radio wave sensor 101 to the right side when viewed directly in front of the radio wave sensor 101 as a result of detecting the direction of the object.

As shown in FIG. 2, the sensor coordinate system can also be represented by polar coordinates having the measurement target distance R and the measurement target azimuth angle θ as components.

The measurement target distance R is the distance from the origin to the object in the sensor coordinate system. The measurement target azimuth θ is the azimuth of the object in the sensor coordinate system. Specifically, the measurement target azimuth θ is the angle formed by the direction from the origin to the object and the direction opposite to the X axis in a plan view of the XY plane from above, and is counterclockwise when viewed from above. To increase.

That is, when the object is located on the right side when viewed directly in front of the radio wave sensor 101 in the sensor coordinate system, the measurement target azimuth θ of the object is a negative value. Further, when the object is located on the left side when viewed directly in front of the radio wave sensor 101 in the sensor coordinate system, the measurement target azimuth θ of the object is a positive value.

The measurement target speed vm is the moving speed of the object along the direction of approaching or moving away from the radio wave sensor 101. That is, the measurement target velocity vm is a component of the relative velocity of the object with respect to the radio wave sensor 101 in the direction of approaching or moving away from the radio wave sensor 101.

The radio wave sensor 101 receives a reflected wave from an object in the irradiation area A1 which is an area where the transmitted radio wave can reach, and based on the received reflected wave, the measurement target distance R, the measurement target azimuth angle θ, and the measurement target azimuth angle θ of the object. The measurement target speed vm is detected.

Specifically, as shown in FIG. 2, the radio wave sensor 101 receives a reflected wave from a vehicle 181 traveling on the road Rd in the irradiation area A1 at a speed vc, and the vehicle 181 is based on the received reflected wave. The measurement target distance R1, the measurement target azimuth angle θ1, and the measurement target speed vm1 are detected.

As shown in FIGS. 1 and 2, the irradiation area A1 and the reference area As are in the same area when the orientation of the radio wave sensor 101 is set to the initial setting, and the orientation of the radio wave sensor 101 is changed after the radio wave sensor 101 is installed. In the displaced state, the areas are different from each other.

The reference area As does not have to be a predetermined area. For example, the radio wave sensor 101 may hold reference area information indicating the reference area As, with the irradiation area A1 set at the time of its installation as the reference area As.

[Radio wave sensor configuration]
(overall structure)
FIG. 3 is a diagram showing a configuration of a radio wave sensor according to an embodiment of the present invention.

With reference to FIG. 3, the radio wave sensor 101 includes a transmission unit 1, a reception unit 2, a difference signal generation unit 3, a control unit 4, a signal processing unit (detection unit) 5, and a clock generation circuit 6. Be prepared.

The transmission unit 1 includes a plurality of transmission antenna elements 21, a plurality of power amplifiers 22, a plurality of variable phase detectors 23, a distributor 24, a switch 25, a directional coupler 26, and a VCO (Voltage-Controlled Oscillator). ) 27 and the voltage generating unit 28.

The difference signal generation unit 3 includes a mixer 33, an IF (Intermediate Frequency) amplifier 34, a low-pass filter 35, and an A / D converter (ADC) 36.

The radio wave sensor 101 includes, for example, Non-Patent Document 1 (Koji Quarter, 2 outsiders, "Expanding Millimeter Wave Technology Application", Shimada Rika Giho, 2011, No. 21, P.37-48) and non-patent. The FM-CW method described in Document 2 (Takayuki Inaba, Tetsuro Kirimoto, "In-Vehicle Millimeter Wave Radar", Automotive Technology, February 2010, Vol. 64, No. 2, P.74-79) It is a radar that detects an object by using it.

(Control unit and clock generation circuit)
The control unit 4 sets, for example, a detection period in which its own radio wave sensor 101 outputs an object detection result once. The detection period includes, for example, M sequences of Seq1 to SeqM. Here, M is an integer of 2 or more. In one sequence, one pattern of radio waves or one sub-pattern of radio waves is transmitted from the transmission unit 1.

The clock generation circuit 6 generates, for example, a clock signal, and outputs the generated clock signal CS to the control unit 4 and the difference signal generation unit 3.

The control unit 4 counts, for example, the number of rising edges of the clock signal CS received from the clock generation circuit 6, and generates a trigger signal Tr every time Ns of the edges are counted. Then, the control unit 4 outputs the generated trigger signal Tr to the transmission unit 1 and the signal processing unit 5. Ns is an integer of 2 or more, and may be a fixed value or a variable value.

(Transmitter)
FIG. 4 is a diagram showing an example of each waveform of the transmission wave and the difference signal generated by the transmission unit and the difference signal generation unit in the radio wave sensor according to the embodiment of the present invention. In FIG. 4, the horizontal axis represents time, and the vertical axis represents the frequencies Ft and Fr of the transmitted radio wave and the received radio wave, the frequency Fb of the difference signal, and the amplitude Ab of the difference signal in order from the upper side of the paper. The frequency Ft of the transmitted radio wave is represented by a solid line, and the frequency Fr of the received radio wave is represented by a broken line. FIG. 4 shows the delay of the received radio wave with respect to the transmitted radio wave.

With reference to FIGS. 3 and 4, the transmission unit 1 repeatedly transmits radio waves of a predetermined pattern. Specifically, the transmission unit 1 repeatedly transmits, for example, a radio wave generated by using the FM-CW modulation method to the irradiation area A1. More specifically, as shown in FIG. 4, for example, the transmission unit 1 repeatedly transmits radio waves of the pattern Pt1 in which the frequency Ft increases by a predetermined amount per unit time to the irradiation area A1.

The control unit 4 outputs the transmission parameters used in the FM-CW system to the transmission unit 1 and the signal processing unit 5, for example, for each detection period. Here, the transmission parameters include the sweep start frequency F2, the frequency sweep direction, the frequency sweep width Δf, the period Tt which is the length of one sequence, the sweep time Ts, and the length Pm of the detection period.

Further, the control unit 4 generates a guard signal GS indicating the start timing of the guard period in which radio waves are not transmitted from the transmission unit 1 at the timing when the sweep time Ts elapses after the trigger signal Tr is generated, and outputs the guard signal GS to the transmission unit 1. do.

The guard signal GS is synchronized with the clock signal CS. The guard period is provided at the rear of each sequence, for example, and continues from the output of the guard signal GS until the trigger signal Tr indicating the start timing of the next sequence is output. The guard period may be provided at the front of each sequence.

The voltage generation unit 28 in the transmission unit 1 receives the trigger signal Tr from the control unit 4, and uses the sweep start frequency F2, the frequency sweep direction, the frequency sweep width Δf, and the sweep time Ts received from the control unit 4 in advance as transmission parameters. Then, a voltage (hereinafter, also referred to as FM modulation voltage) whose magnitude increases at a constant rate is generated and output to the VCO 27 until the guard signal GS is received from the control unit 4.

The VCO 27 generates a transmitted wave RFt in the 24 GHz band having a frequency sweep width of Δf according to the FM modulation voltage received from the voltage generating unit 28, and outputs the transmitted wave RFt to the directional coupler 26.

The directional coupler 26 distributes the transmitted wave RFt received from the VCO 27 to the switch 25 and the difference signal generation unit 3.

The switch 25 has a first end connected to the directional coupler 26 and a second end connected to the distributor 24. The switch 25 receives the trigger signal Tr from the control unit 4, transitions to the ON state, and electrically connects the first end and the second end. On the other hand, the switch 25 receives the guard signal GS from the control unit 4, transitions to the off state, and electrically insulates the first end and the second end. As a result, the transmitted wave RFt output by the VCO 27 is not transmitted to the distributor 24 during the guard period, and is transmitted to the distributor 24 during a period different from the guard period.

The distributor 24 receives the transmitted wave RFt from the switch 25 and distributes the received transmitted wave RFt to the plurality of variable phase devices 23.

The variable phase device 23 receives the transmitted wave RFt distributed from the distributor 24, shifts the phase of the received transmitted wave RFt according to the control of the control unit 4, and shifts the phase of the received transmitted wave RFt to the corresponding power. Output to amplifier 22.

The power amplifier 22 amplifies the transmitted wave RFt received from the variable phase device 23, and transmits the amplified transmitted wave RFt to the irradiation area A1 via the transmitting antenna element 21.

(Receiver and difference signal generator)
The receiving unit 2 receives the radio wave from the irradiation area A1. More specifically, the receiving unit 2 has, for example, an array antenna including Q antenna elements arranged in the horizontal direction, and outputs the received wave RFr corresponding to the radio wave received by each antenna element to the difference signal generation unit 3. do. Q is an integer of 2 or more.

The difference signal generation unit 3 generates a difference signal Ba1 having a frequency component of the difference between the frequency component of the radio wave transmitted by the transmission unit 1 and the frequency component of the radio wave received by the reception unit 2.

More specifically, the mixer 33 in the difference signal generation unit 3 generates an analog difference signal Ba1 having a frequency component of the difference between the transmission wave RFt received from the transmission unit 1 and the reception wave RFr received from the reception unit 2.

The time change of the frequency Fb and the amplitude Ab of the difference signal Ba1 is shown in FIG. The mixer 33 outputs the generated difference signal Ba1 to the IF amplifier 34.

The IF amplifier 34 amplifies the difference signal Ba1 received from the mixer 33 and outputs it to the low-pass filter 35.

The low-pass filter 35 attenuates components having a frequency higher than a predetermined frequency among the frequency components of the difference signal Ba1 amplified by the IF amplifier 34.

The A / D converter 36 performs sampling processing of the difference signal Ba1 at, for example, the period Tc of the clock signal CS. More specifically, the A / D converter 36 sets the difference signal Ba1 that has passed through the low-pass filter 35 in q bits (q is 2 or more) for each sampling period Tc according to the timing of the rising edge of the clock signal CS received from the clock generation circuit 6. It is converted into a digital difference signal Bd1 (an integer of).

In FIG. 4, each sampling timing in the sequences Seq1 and Seq2 is indicated by a white circle. For example, sampling numbers 1 to 12 indicating the sampling order are assigned to the sampling timing in each sequence. The A / D converter 36 outputs the converted difference signal Bd1 to the signal processing unit 5.

(Signal processing unit)
The signal processing unit 5 detects an object in the irradiation area A1 based on, for example, the radio wave received by the receiving unit 2. Specifically, the signal processing unit 5 detects, for example, the measurement target azimuth θ, the measurement target distance R, and the measurement target speed vm based on the radio waves received by the reception unit 2.

More specifically, the signal processing unit 5 receives the trigger signal Tr from the control unit 4 and samples each difference signal received from the difference signal generation unit 3 during the sweep time Ts at predetermined sampling cycles. Generate a time spectrum of the difference signal for each antenna element.

As a result, the signal processing unit 5 accumulates the time spectrum of the Q set corresponding to each of the Q antenna elements at the expiration of the sweep time Ts.

The signal processing unit 5 accumulates a Q-set time spectrum each time a new trigger signal Tr is received from the control unit 4.

As a result, the signal processing unit 5 accumulates M sets of Q set time spectra at the expiration of the detection period.

Hereinafter, in the m-th sweep time Ts, the time spectrum of the difference signal based on the received signal received by the q-th antenna element is defined as the time spectrum TS (m, q). Here, m is an integer from 1 to M. q is an integer from 1 to Q.

The signal processing unit 5 generates the frequency spectrum FS (1,1) by, for example, processing the time spectrum TS (1,1) by FFT (Fast Fourier Transform).

The vertical and horizontal axes of the frequency spectrum FS (1,1) are amplitude and frequency, respectively. Further, the horizontal axis is, for example, Non-Patent Document 3 (Eugin Hyun, 2 outsiders, "A Pedestrian Detection Scene Using a Coherent Phase Distance Method Method Based on 2D Radar 16 Years", Vol. 16 and Doppler FMC. It is possible to convert to the measurement target distance R according to the method described on P.124).

The signal processing unit 5 has, for example, a dark spectrum which is a frequency spectrum detected when no object is present in the irradiation area A1. More specifically, the signal processing unit 5 holds, for example, dark information indicating the correspondence between the target distance Dc and the dark spectrum.

The signal processing unit 5 receives the target information from the control unit 4, acquires the dark spectrum corresponding to the target distance Dc indicated by the received target information from the dark information, and acquires the dark spectrum from the frequency spectrum FS (1, 1). By subtracting the spectrum, the processed frequency spectrum FS (1,1) is generated.

The signal processing unit 5 performs peak detection processing for detecting a peak having an amplitude equal to or higher than a predetermined threshold value in the generated processed frequency spectrum FS (1, 1). Then, the signal processing unit 5 calculates the measurement target distance R, the measurement target azimuth θ, and the measurement target speed vm for each detected peak. More specifically, the signal processing unit 5 calculates the measurement target distance R by converting the frequency of the detected peak.

Further, the signal processing unit 5 is described in, for example, Non-Patent Document 4 (Nobuyoshi Kikuma, "Adaptive Signal Processing by Array Antenna", First Edition, Science and Technology Publishing Co., Ltd., November 1998, p.181, p.194). The measurement target azimuth θ corresponding to the detected peak is calculated based on the time spectra TS (1,1) to (1,Q) according to the described MUSIC (MUSIC Signal Processing) method, Capon method or beamforming method. ..

Further, the signal processing unit 5 calculates the measurement target speed vm corresponding to the detected peak based on the time spectra TS (1,1) to (M, 1) according to, for example, the method described in Non-Patent Document 3. do.

The signal processing unit 5 outputs detection result information indicating the measurement target distance R, the measurement target azimuth θ, and the measurement target speed vm for each detected peak to the control unit 4.

FIG. 5 is a table showing an example of a detection result by the signal processing unit in the radio wave sensor according to the embodiment of the present invention.

With reference to FIG. 5, when the signal processing unit 5 detects the objects 1, 2, 3, ... During a certain detection period, the measurement target distances R of the objects 1, 2, 3, ... The detection result information indicating the measurement target azimuth angle θ and the measurement target speed vm is output to the control unit 4.

The signal processing unit 5 may be configured to calculate the S / N ratio (Signal-to-Noise ratio) based on the generated frequency spectrum. For example, the signal processing unit 5 calculates the S / N ratio for each detected object, and obtains detection result information indicating the measurement target distance R, the measurement target azimuth angle θ, the measurement target speed vm, and the S / N ratio of each object. Output to control unit 4.

[Detailed configuration of control unit]
FIG. 6 is a diagram showing a detailed configuration of a control unit in the radio wave sensor according to the embodiment of the present invention.

With reference to FIG. 6, the control unit 4 includes an acquisition unit 51, an area calculation unit 52, a deviation calculation unit 53, a deviation correction unit 54, a notification unit 55, and a storage unit 56.

(Calculation of detectable area)
The acquisition unit 51 receives the detection result information output from the signal processing unit 5 and stores the detection result information in the storage unit 56.

The area calculation unit 52 calculates the detectable area Ap of the radio wave sensor 101 based on the plurality of detection result information stored in the storage unit 56. The detectable area Ap is, for example, the area of the road Rd in the irradiation area A1.

FIG. 7 is a diagram showing an example of a detectable area calculated by an area calculation unit in the radio wave sensor according to the embodiment of the present invention.

With reference to FIG. 7, the area calculation unit 52 plots points P indicating the positions of one or more objects detected by the signal processing unit 5 on the sensor coordinate system. More specifically, the area calculation unit 52 plots, for example, a plurality of points P indicating the positions of the plurality of objects detected at the predetermined time each time a predetermined time including the plurality of detection periods elapses. When the same object is detected a plurality of times in a predetermined time, the area calculation unit 52 plots a plurality of points P indicating the positions of the objects.

Then, the area calculation unit 52 calculates the area defined by each point P as the detectable area Ap, and outputs the detectable area information indicating the calculated detectable area Ap to the deviation calculation unit 53.

For example, the area calculation unit 52 calculates an area where the number or density of points P per unit area is equal to or greater than a predetermined threshold value as a detectable area Ap. In the example shown in FIG. 7, the detectable area Ap is included in the area where the distance from the radio wave sensor 101 is 0 m to 300 m.

The area calculation unit 52 may calculate the smallest area in which the plotted points P fit as the detectable area Ap.

Further, the area calculation unit 52 counts, for example, the number of detected objects for each lane based on a plurality of detection result information stored in the storage unit 56, and each in the lane where the count number is equal to or more than a predetermined value. The points P indicating the positions of the objects may be plotted, and the area defined by each point P may be calculated as the detectable area Ap. In this case, the area calculation unit 52, for example, after calculating the detectable area Ap, resets the count number to zero and counts the number of newly detected objects.

Further, when the detection result information stored in the storage unit 56 indicates the S / N ratio corresponding to each object, the area calculation unit 52 determines, for example, the corresponding S / N ratio among the plurality of detected objects. The detectable area Ap may be calculated by plotting points P indicating the positions of one or more objects in which is equal to or greater than a predetermined threshold value on the sensor coordinate system.

Further, the area calculation unit 52 may calculate the detectable area Ap based on the travel locus Pa of each detected object. More specifically, the area calculation unit 52 determines the measurement target distance R, the measurement target azimuth θ, and the measurement target for each detected object based on, for example, a plurality of detection result information stored in the storage unit 56. A plurality of sets of speed vm are acquired, and a traveling locus Pa is calculated based on the obtained plurality of sets.

Then, by confirming the extending direction of the travel locus Pa of each of the calculated objects, the area calculation unit 52 determines, for example, an area of the irradiation area A1 in which an object traveling in a direction away from its own radio wave sensor 101 exists. The excluded area is calculated as the detectable area Ap.

(Calculation of deviation)
(A) Calculation of Pan Angle With reference to FIG. 6 again, reference area information indicating the reference area As is stored in the storage unit 56.

The deviation calculation unit 53 calculates the deviation of the angle between the reference area As and the detectable area Ap based on the reference area information stored in the storage unit 56 and the detectable area information received from the area calculation unit 52. .. Then, the deviation calculation unit 53 calculates the deviation of the pan angle of the radio wave sensor 101 based on the calculated deviation of the angle, and outputs the pan angle information indicating the calculated deviation of the pan angle to the deviation correction unit 54. The deviation calculation unit 53 may calculate the calculated angle deviation as the pan angle deviation of the radio wave sensor 101, or calculate a value different from the calculated angle deviation as the pan angle deviation of the radio wave sensor 101. You may.

FIG. 8 is a diagram (Example 1) for explaining a method of calculating the pan angle deviation by the deviation calculation unit in the radio wave sensor according to the embodiment of the present invention.

With reference to FIG. 8, here, as shown in the upper side of FIG. 8, it is assumed that the irradiation area A1 is tilted diagonally to the right with respect to the reference area As. In this case, the detectable area Ap, which is included in the irradiation area A1 and is the area where the object to be detected is detected, is the hatched area in FIG.

The boundary line BL1 between the detectable area Ap and the area other than the detectable area Ap in the irradiation area A1 is along the boundary line extending in the vertical direction of the reference area As, that is, along the X axis, as shown in the lower part of FIG. It tilts diagonally to the left with respect to the boundary line BL2 extending along the line.

The deviation calculation unit 53 calculates, for example, the deviation of the angle between the reference area As and the detectable area Ap, that is, the angle α formed by the boundary line BL1 and the boundary line BL2, thereby causing the deviation of the pan angle of the radio wave sensor 101. Calculate a certain angle α.

FIG. 9 is a diagram (Example 2) for explaining a method of calculating the pan angle deviation by the deviation calculation unit in the radio wave sensor according to the embodiment of the present invention.

With reference to FIG. 9, here, it is assumed that the irradiation area A1 is tilted diagonally to the left with respect to the reference area As, as shown in the upper side of FIG. In this case, the detectable area Ap, which is included in the irradiation area A1 and is the area where the object to be detected is detected, is the hatched area in FIG.

The boundary line BL1 between the detectable area Ap and the area other than the detectable area Ap in the irradiation area A1 is along the boundary line extending in the vertical direction of the reference area As, that is, along the X axis, as shown in the lower part of FIG. It tilts diagonally to the right with respect to the boundary line BL2 extending along the line.

The deviation calculation unit 53 calculates, for example, the deviation of the angle between the reference area As and the detectable area Ap, that is, the angle β formed by the boundary line BL1 and the boundary line BL2, thereby causing the deviation of the pan angle of the radio wave sensor 101. Calculate a certain angle β.

The angle calculated by the deviation calculation unit 53 is a positive value when the irradiation area A1 is tilted diagonally to the right with respect to the reference area As, and the irradiation area A1 is diagonally to the left with respect to the reference area As. If it is tilted, it will be a negative value.

The deviation calculation unit 53 may calculate the deviation of the pan angle of the radio wave sensor 101 based on the traveling direction of the object in the detectable area Ap and the reference area As.

For example, the deviation calculation unit 53 acquires and acquires a plurality of sets of the measurement target distance R, the measurement target azimuth θ, and the measurement target speed vm of a certain object based on a plurality of detection results stored in the storage unit 56. The traveling locus Pa of the object shown in FIG. 8 or 9 is calculated based on the plurality of sets.

Further, the deviation calculation unit 53 forms, for example, a traveling direction of the calculated object, which is the extending direction of the traveling locus Pa of the object, and a straight line BL3 parallel to the boundary line BL2 extending in the vertical direction of the reference area As. Calculate the angle α or the angle β. Then, the deviation calculation unit 53 calculates the deviation of the pan angle of the radio wave sensor 101 based on the calculated angle α or angle β.

(B) Calculation of tilt angle Further, the deviation calculation unit 53 calculates the difference L between the distances of the reference area As and the detectable area Ap with respect to the radio wave sensor 101, and the tilt angle of the radio wave sensor 101 is calculated based on the calculated difference L. Calculate the deviation. Then, the deviation calculation unit 53 outputs the tilt angle information indicating the calculated deviation of the tilt angle to the deviation correction unit 54.

FIG. 10 is a view seen from the side of the radio wave sensor in the installation example of the radio wave sensor for explaining the method of calculating the tilt angle by the deviation calculation unit in the radio wave sensor according to the embodiment of the present invention.

FIG. 11 is a diagram showing a detectable area for explaining a method of calculating a tilt angle deviation by a deviation calculation unit in the radio wave sensor according to the embodiment of the present invention.

With reference to FIGS. 10 and 11, it is assumed here that the radio wave sensor 101 is displaced downward as compared with the time of installation. In this case, the irradiation area A1 is shifted to the side closer to the radio wave sensor 101 with respect to the reference area As.

The distance between the first end Se1 on the side away from the radio wave sensor 101 in the reference area As and the radio wave sensor 101 is defined as Df, and the distance between the second end Se2 on the radio wave sensor 101 side in the reference area As and the radio wave sensor 101 is defined as Df. Let it be Dn. Further, the distance between the intermediate position Pc of the first end portion Se1 and the second end portion Se2 and the radio wave sensor 101, that is, the above-mentioned target distance Dc is Dc = (Df + Dn) / 2.

Further, the angle formed by the vector from the radio wave sensor 101 to the intermediate position Pc and the XY plane in the state where the orientation of the radio wave sensor 101 is initially set is defined as the elevation angle φ.

The deviation calculation unit 53 acquires the distance Dp between the end of the detectable area Ap on the side away from the radio wave sensor 101 and the radio wave sensor 101 based on the detectable area information received from the area calculation unit 52. Further, the deviation calculation unit 53 calculates the distance L, which is the difference between the acquired distance Dp and the distance Df.

Further, the deviation calculation unit 53 specifies the position of the point Px that is closer to the radio wave sensor 101 side by the distance L from the intermediate position Pc based on the calculated distance L.

Then, the deviation calculation unit 53 determines the deviation of the tilt angle of the radio wave sensor 101 based on the known values of the height Hr, the elevation angle φ, and the distance Dc of the radio wave sensor 101 from the road Rd, and the calculated distance L. , The angle γ formed by the vector from the radio wave sensor 101 to the intermediate position Pc and the vector from the radio wave sensor 101 to the point Px is calculated.

The control unit 4 of the radio wave sensor 101 may further include an acceleration sensor (not shown) that detects the gravitational acceleration of the radio wave sensor 101. In this case, the deviation calculation unit 53 may calculate the deviation of the tilt angle of the radio wave sensor 101 based on the detection result by the acceleration sensor.

In such a configuration, even if both the pan angle and the tilt angle of the radio wave sensor 101 are deviated, it is possible to correct the deviation of the tilt angle of the radio wave sensor 101 based on the detection result by the acceleration sensor. Is. Therefore, the deviation of the pan angle of the radio wave sensor 101 can be corrected based on the detection result by the signal processing unit 5 of the radio wave sensor 101 after the tilt angle is corrected.

(Correction of deviation and notification of abnormality)
With reference to FIG. 6 again, the deviation correction unit 54 receives the pan angle information and the tilt angle information from the deviation calculation unit 53, and the deviation of the pan angle of the radio wave sensor 101 based on the pan angle information and the tilt angle information. And the deviation of the tilt angle are corrected respectively.

More specifically, the deviation correction unit 54 corrects the deviation of the radio wave sensor 101 in the left-right direction when, for example, the pan angle information indicating the deviation of the pan angle larger than the predetermined value Th1 is received. Further, the deviation correction unit 54 corrects the deviation of the radio wave sensor 101 in the vertical direction when, for example, the tilt angle information indicating the deviation of the tilt angle larger than the predetermined value Th2 is received.

The deviation correction unit 54 may output an abnormality information transmission instruction indicating an abnormality of the radio wave sensor 101 to the notification unit 55.

More specifically, the deviation correction unit 54 counts and counts the number of times that the pan angle information indicating the deviation of the pan angle larger than the predetermined value Th1 or the tilt angle information indicating the deviation of the tilt angle larger than the predetermined value Th2 is received. The value is stored in the storage unit 56.

Further, the deviation correction unit 54 confirms the count value N in the storage unit 56, and if the count value N is larger than the predetermined value Nt, outputs an abnormality information transmission instruction to the notification unit 55.

The notification unit 55 receives an instruction to transmit the abnormality information from the deviation correction unit 54, and transmits the abnormality information to the external server 121 via the relay device 161.

The notification unit 55 may transmit a plurality of detection result information stored in the storage unit 56 together with the abnormality information to the external server 121 via the relay device 161.

(Specific example of deviation correction)
(A) Example 1
For example, the deviation correction unit 54 transmits control information for rotating a gear or the like that can change the direction of the radio wave sensor 101 in the left-right direction to a drive unit (not shown). As a result, the deviation correction unit 54 mechanically corrects the deviation of the radio wave sensor 101 in the left-right direction.

Further, for example, the deviation correction unit 54 transmits control information for rotating a gear or the like whose orientation can be changed in the vertical direction of the radio wave sensor 101 to a drive unit (not shown). As a result, the deviation correction unit 54 mechanically corrects the deviation of the radio wave sensor 101 in the vertical direction.

(B) Example 2
In the deviation correction unit 54, for example, when a plurality of transmitting antenna elements 21 in the transmitting unit 1 shown in FIG. 3 are arranged along the horizontal direction, the phase difference between the radio waves radiated from the plurality of transmitting antenna elements 21 is different. By adjusting the above, the deviation of the radio wave sensor 101 in the left-right direction may be corrected.

More specifically, the shift correction unit 54 calculates, for example, a plurality of phase shift amounts to be given to the plurality of variable phase devices 23 in the transmission unit 1 based on the shift of the pan angle indicated by the pan angle information. Then, the shift correction unit 54 outputs each of the plurality of phase shift information indicating the calculated plurality of phase shift amounts to the corresponding variable phase device 23.

Each variable phase device 23 receives phase shift information from the control unit 4, shifts the phase of the radio wave received from the distributor 24 by the amount of the phase shift indicated by the phase shift information, and transfers the radio wave after the phase shift to the corresponding power. Output to amplifier 22. As a result, the phase difference between the radio waves radiated from the plurality of transmitting antenna elements 21 is adjusted, and the irradiation area A1 is corrected.

When the plurality of transmitting antenna elements 21 in the transmitting unit 1 are arranged along the vertical direction, the deviation correction unit 54 is the position between the radio waves radiated from the plurality of transmitting antenna elements 21 by the same method. The phase difference may be adjusted to correct the vertical deviation of the radio wave sensor 101.

(C) Example 3
The deviation correction unit 54 may be configured to correct the detection result by the signal processing unit 5 based on the pan angle information and the tilt angle information.

For example, it is assumed that the pan angle information indicates that the radio wave sensor 101 is shifted to the right by an angle α. In this case, the deviation correction unit 54 changes, for example, the measurement target azimuth angle θ of each object included in the detection result stored in the storage unit 56 to a value obtained by subtracting the angle α and overwrites it.

In the radio wave sensor 101 according to the embodiment of the present invention, the deviation calculation unit 53 calculates both the pan angle deviation and the tilt angle deviation of the radio wave sensor 101, but the configuration is not limited to this. The configuration may be such that either the pan angle deviation or the tilt angle deviation is calculated.

<Flow of operation>
The radio wave sensor 101 includes a computer, and an arithmetic processing unit such as a CPU in the computer reads and executes a program including a part or all of each step in the following flowchart from a memory (not shown). The program for this device can be installed externally. The program of this device is distributed in a state of being stored in a recording medium.

FIG. 12 is a flowchart defining an operation procedure when the radio wave sensor according to the embodiment of the present invention calculates and corrects its own deviation.

With reference to FIG. 12, first, the transmission unit 1 transmits a radio wave to the irradiation area A1 (step S11).

Next, the receiving unit 2 receives the radio wave from the irradiation area A1 and outputs the received signal corresponding to the received radio wave to the difference signal generation unit 3 (step S12).

Next, the difference signal generation unit 3 generates a difference signal having a frequency component of the difference between the frequency component of the radio wave transmitted by the transmission unit 1 and the frequency component of the radio wave received by the reception unit 2, and the generated difference. The signal is output to the signal processing unit 5 (step S13).

Next, the signal processing unit 5 generates a time spectrum based on each difference signal received from the difference signal generation unit 3, and generates a frequency spectrum by performing FFT processing on the generated time spectrum. Then, the signal processing unit 5 performs detection processing for detecting the measurement target distance R, the measurement target azimuth θ, and the measurement target speed vm of the object in the irradiation area A1 based on the generated frequency spectrum (step S14).

Next, the signal processing unit 5 stores the detection result information indicating the detection result in the storage unit 56 (step S15).

Next, the area calculation unit 52 confirms, for example, whether or not a predetermined time has elapsed from the timing when the detectable area Ap was previously calculated (step S16).

Then, when the predetermined time has not elapsed from the above timing (“NO” in step S16), the area calculation unit 52 does not calculate the detectable area Ap, and the radio wave sensor 101 does not calculate the detectable area Ap until the predetermined time elapses. In steps S11 to S15, the operations of steps S11 to S15 are repeated.

On the other hand, when the predetermined time elapses from the above timing (“YES” in step S16), the area calculation unit 52 has a plurality of points in the sensor coordinate system based on the plurality of detection result information stored in the storage unit 56. P is plotted to calculate the detectable area Ap. Then, the area calculation unit 52 outputs the detectable area information indicating the calculated detectable area Ap to the deviation calculation unit 53 (step S17).

Next, the deviation calculation unit 53 shifts the pan angle of the radio wave sensor 101 and the radio wave sensor 101 based on the detectable area information received from the area calculation unit 52 and the reference area information stored in the storage unit 56. Calculate the deviation of the tilt angle of. Then, the deviation calculation unit 53 outputs the pan angle information indicating the calculated pan angle deviation and the tilt angle information indicating the calculated tilt angle deviation to the deviation correction unit 54 (step S18).

Next, the deviation correction unit 54 confirms whether or not the deviation of the pan angle indicated by the pan angle information received from the deviation calculation unit 53 is larger than the predetermined value Th1. Further, the deviation correction unit 54 confirms whether or not the deviation of the tilt angle indicated by the tilt angle information received from the deviation calculation unit 53 is larger than the predetermined value Th2 (step S19).

Next, the deviation correction unit 54 corrects the deviation of the radio wave sensor 101 when the deviation of the pan angle is the predetermined value Th1 or less and the deviation of the tilt angle is the predetermined value Th2 or less (“YES” in step S19). Wait without doing. Then, the operations after step S11 are performed again.

On the other hand, in the deviation correction unit 54, when the deviation of the pan angle is larger than the predetermined value Th1, the deviation of the tilt angle is larger than the predetermined value Th2, or the deviation of the pan angle is larger than the predetermined value Th1 and the deviation of the tilt angle is larger than the predetermined value Th1. When it is larger than the predetermined value Th2 (“NO” in step S19), the count value N is incremented (step S20).

Next, the deviation correction unit 54 confirms whether or not the count value N is larger than the predetermined value Nt (step S21).

When the count value N is larger than the predetermined value Nt (“YES” in step S21), the deviation correction unit 54 outputs an abnormality information transmission instruction indicating an abnormality of the radio wave sensor 101 to the notification unit 55. Then, the notification unit 55 notifies the abnormality of the radio wave sensor 101 by receiving the transmission instruction of the abnormality information output from the deviation correction unit 54 and transmitting the abnormality information to the external server 121 via the relay device 161 (). Step S22).

On the other hand, when the count value N is equal to or less than the predetermined value Nt (“NO” in step S21), the deviation correction unit 54 does not transmit the abnormality information, and the radio wave sensor 101 is based on the pan angle information and the tilt angle information. Correct the deviation.

For example, in the deviation correction unit 54, when a plurality of transmitting antenna elements 21 are arranged along the horizontal direction and the deviation of the pan angle is larger than a predetermined value Th1, the radio waves radiated from each of the plurality of transmitting antenna elements 21. By adjusting the phase difference between them, the deviation of the radio wave sensor 101 in the left-right direction is corrected.

Further, in the deviation correction unit 54, for example, when a plurality of transmitting antenna elements 21 are arranged along the vertical direction and the deviation of the tilt angle is larger than a predetermined value Th2, they are radiated from each of the plurality of transmitting antenna elements 21. By adjusting the phase difference between the radio waves, the vertical deviation of the radio wave sensor 101 is corrected.

Further, in the deviation correction unit 54, for example, a plurality of transmitting antenna elements 21 are arranged along both the horizontal direction and the vertical direction, the pan angle deviation is larger than the predetermined value Th1, and the tilt angle deviation is predetermined. It is assumed that the value is larger than Th2. In this case, by adjusting the phase difference between the radio waves radiated from each of the plurality of transmitting antenna elements 21, the deviation of the radio wave sensor 101 in both the left-right direction and the up-down direction is corrected (step S23).

By the way, for example, in the vehicle-mounted radio wave sensor described in Patent Document 1, the detection target area of the object is set based on the relative angle and distance with respect to the radio wave sensor.

Further, a radio wave sensor provided above the road for detecting an object such as a vehicle traveling on the road is known. Such a radio wave sensor is installed with its orientation adjusted so that it can detect an object in the target area.

However, there is a possibility that the direction of the radio wave sensor may be deviated due to the influence of the vibration of the support column supporting the road or the radio wave sensor, strong wind, etc., and the object may not be detected or falsely detected in the target area.

On the other hand, in the radio wave sensor 101 according to the embodiment of the present invention, the transmission unit 1 transmits radio waves. The receiving unit 2 receives the radio wave. The signal processing unit 5 detects an object based on the radio wave received by the receiving unit 2. The area calculation unit 52 calculates the detectable area Ap of the radio wave sensor 101 based on the plurality of detection results of the signal processing unit 5. Then, the deviation calculation unit 53 calculates the deviation between the reference area As, which is the detection area held by the radio wave sensor 101, and the detectable area Ap calculated by the area calculation unit 52.

In this way, by calculating the deviation between the reference area As and the detectable area Ap based on the plurality of detection results of the object, the deviation from the calculation result is obtained without manually measuring the deviation in the direction of the radio wave sensor 101. Can be recognized.

Therefore, in the radio wave sensor 101 according to the embodiment of the present invention, the deviation of the orientation of the radio wave sensor 101 can be easily measured.

Further, in the radio wave sensor 101 according to the embodiment of the present invention, the deviation calculation unit 53 calculates the deviation of the pan angle of the radio wave sensor 101 based on the deviation of the angle between the reference area As and the detectable area Ap.

In this way, with the configuration of calculating the deviation of the angle with respect to the reference area As, the deviation of the pan angle of the radio wave sensor 101 can be measured by a simple calculation process.

Further, in the radio wave sensor 101 according to the embodiment of the present invention, the deviation calculation unit 53 calculates the tilt angle of the radio wave sensor 101 based on the difference L between the distances of the reference area As and the detectable area Ap with respect to the radio wave sensor 101. ..

With such a configuration, for example, a simple calculation process for calculating the difference L between the distance Df from the radio wave sensor 101 to the end of the reference area As and the distance Dp from the radio wave sensor 101 to the end of the detectable area Ap. Can measure the deviation of the tilt angle of the radio wave sensor 101.

Further, in the radio wave sensor 101 according to the embodiment of the present invention, the deviation calculation unit 53 determines the reference area As based on the traveling direction of the object in the detectable area Ap detected by the signal processing unit 5 and the reference area As. And the detectionable area Ap are calculated.

With such a configuration, for example, even when the detectable area Ap has a complicated shape, the reference area As and the detectable area Ap are combined based on the traveling direction of the object in the detectable area Ap. The deviation of the angle can be calculated.

Further, in the radio wave sensor 101 according to the embodiment of the present invention, the transmission unit 1 includes a plurality of transmission antenna elements 21. Then, the deviation correction unit 54 adjusts the phase difference between the radio waves radiated from the transmitting antenna element 21 based on the deviation between the reference area As and the detectable area Ap calculated by the deviation calculation unit 53. , Correct the above deviation.

With such a configuration, it is possible to correct the deviation of the orientation of the radio wave sensor 101 without human intervention and prevent non-detection or false detection of an object.

Further, in the deviation measurement method in the radio wave sensor 101 according to the embodiment of the present invention, the transmission unit 1 first transmits radio waves. Next, the receiving unit 2 receives the radio wave. Next, the signal processing unit 5 detects the object based on the radio wave received by the receiving unit 2. Next, the area calculation unit 52 calculates the detectable area Ap of the radio wave sensor 101 based on the plurality of detection results of the signal processing unit 5. Next, the deviation calculation unit 53 calculates the deviation between the reference area As, which is the detection area held by the radio wave sensor 101, and the detectable area Ap calculated by the area calculation unit 52.

In this way, by the method of calculating the deviation between the reference area As and the detectable area Ap based on the plurality of detection results of the object, the deviation from the calculation result is obtained without manually measuring the deviation of the direction of the radio wave sensor 101. Can be recognized.

Therefore, in the deviation measuring method in the radio wave sensor 101 according to the embodiment of the present invention, the deviation in the direction of the radio wave sensor 101 can be easily measured.

It should be considered that the above embodiments are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The above description includes the features described below.
[Appendix 1]
It ’s a radio wave sensor,
A transmitter that transmits radio waves and
The receiver that receives radio waves and
A detector that detects an object based on the radio waves received by the receiver,
An area calculation unit that calculates the detectable area of the radio wave sensor based on a plurality of detection results of the detection unit, and an area calculation unit.
It is provided with a deviation calculation unit for calculating the deviation between the reference area, which is the detection area held by the radio wave sensor, and the detectable area calculated by the area calculation unit.
The radio wave sensor is a millimeter-wave radar that detects a vehicle located on the road.
The detection unit detects the distance of the vehicle from the radio wave sensor, the azimuth angle to the radio wave sensor, and the moving speed with respect to the radio wave sensor.
Based on the plurality of detection results, the area calculation unit plots points indicating the positions of the plurality of vehicles on the sensor coordinate system, and the area defined by each of the plotted points is the detectable area. The radio wave sensor calculated as.

1 Transmitter 2 Receiver 3 Difference signal generator 4 Control 5 Signal processing (detector)
6 Clock generation circuit 21 Transmit antenna element 22 Power amplifier 23 Variable phase detector 24 Distributor 25 Switch 26 Directional coupler 27 VCO
28 Voltage generator 33 Mixer 34 IF amplifier 35 Low-pass filter 36 A / D converter 51 Acquisition unit 52 Area calculation unit 53 Deviation calculation unit 54 Deviation correction unit 55 Notification unit 56 Storage unit 101 Radio wave sensor 181 Vehicle

Claims (6)

It ’s a radio wave sensor,
A transmitter that transmits radio waves and
The receiver that receives radio waves and
A detector that detects the position of an object based on the radio waves received by the receiver, and
An area calculation unit that calculates the position of a detection target area , which is a road area in the radio wave irradiation area of the radio wave sensor, based on a plurality of detection results of the detection unit.
E Bei a deviation calculation unit for calculating a deviation between the position of the detection target area calculated by the position and the area calculation unit of the reference area the radio wave sensor is a detection area held,
The deviation calculation unit is a radio wave sensor that calculates a deviation of the tilt angle of the radio wave sensor based on the difference in distance between the reference area and the detection target area with respect to the radio wave sensor. The radio wave sensor according to claim 1, wherein the deviation calculation unit calculates the deviation of the pan angle of the radio wave sensor based on the angle deviation between the reference area and the detection target area. The deviation calculation unit calculates the deviation of the angle between the reference area and the detection target area based on the traveling direction of the object in the detection target area detected by the detection unit and the position of the reference area. The radio wave sensor according to claim 2. The transmitter includes a plurality of antenna elements and includes a plurality of antenna elements.
The radio wave sensor further
Any of claims 1 to 3 , further comprising a correction unit that corrects the deviation by adjusting the phase difference between radio waves radiated from the antenna element based on the deviation calculated by the deviation calculation unit. The radio wave sensor according to item 1. It is a deviation measurement method for radio wave sensors.
Steps to transmit radio waves and
Steps to receive radio waves and
Steps to detect the position of an object based on the received radio waves,
Based on a plurality of detection results, a step of calculating the position of the detection target area , which is a road area, among the radio wave irradiation areas of the radio wave sensor, and
Look including the step of calculating the reference area location the radio wave sensor is a detection area that holds, the deviation between the calculated positions of the detection target area,
A deviation measuring method for calculating the deviation of the tilt angle of the radio wave sensor based on the difference in distance between the reference area and the detection target area with respect to the radio wave sensor in the step of calculating the deviation. A deviation measurement program used in radio wave sensors.
Computer,
A transmitter that transmits radio waves and
The receiver that receives radio waves and
A detector that detects the position of an object based on the radio waves received by the receiver, and
An area calculation unit that calculates the position of a detection target area , which is a road area, among the radio wave irradiation areas of the radio wave sensor, based on a plurality of detection results of the detection unit.
Deviation calculation unit that calculates a deviation between the position of the detection target area calculated by the position and the area calculation unit of the reference area the radio wave sensor is a detection area held,
It is a program to function as
The deviation calculation unit is a deviation measurement program that calculates the deviation of the tilt angle of the radio wave sensor based on the difference in distance between the reference area and the detection target area with respect to the radio wave sensor.

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