JP2019179011A - Radar device and correction method for radar device - Google Patents

Abstract

To reliably correct angles by a simple configuration.SOLUTION: Provided is a radar device 1 for detecting a target and mounted in a moving body, comprising: detection means (transmission unit 11 and reception unit 16) for transmitting a signal to the target and detecting the azimuth angle of the target on the basis of a reflected signal; calculation means (control/processing unit 15) for calculating the azimuth angle of the target at a first position from the physical relation of the target and the moving body when the moving body exists at a first position and when it exists at a second position different from the first position; and correction means (control/processing unit 15) for correcting the azimuth angle detected by the detection means when the azimuth angle of the target detected at the first position by the detection means and the azimuth angle calculated by the calculation means are different.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a radar apparatus and a radar apparatus correction method.

  Patent Document 1 discloses a technique for correcting the beam center by calculating a forward road-side angle based on a detected forward relative speed and a vehicle speed.

  Patent Document 2 discloses a technique for calculating an angle from a relative speed of an object detected behind, an observation angle, and an in-house speed, correcting a shift using a histogram, and correcting the angle.

Japanese Patent Application Laid-Open No. 07-209414 JP-A-2006-219992

  However, in the techniques shown in Patent Documents 1 and 2, the relative speed may be erroneously recognized due to the shape or material of the object, and in such a case, the correction value causes a problem. There is.

  In addition, when the mounting angle is corrected, there is a problem in that a deviation may occur due to mechanical correction.

  It is an object of the present invention to provide a radar apparatus and a radar apparatus correction method that can reliably perform angle correction with a simple configuration.

In order to solve the above-described problems, the present invention provides a radar device mounted on a moving body that detects a target, transmits a signal to the target, and determines an azimuth angle of the target based on a reflected signal. From the positional relationship between the target and the moving body in the case where the detecting means for detecting, the moving body is present at the first position, and the second moving body is located at a second position different from the first position, When the calculation means for calculating the azimuth angle of the target and the azimuth angle of the target detected by the detection means at the first position are different from the azimuth angle calculated by the calculation means, Correction means for correcting the azimuth angle detected by the detection means.
According to such a configuration, angle correction can be reliably performed with a simple configuration.

In the present invention, the calculating means may determine the direction of the target based on the distance d between the target at the second position and the distance D between the first position and the second position. An angle is calculated.
According to such a configuration, the angle correction can be performed by a simple calculation.

The present invention further includes position information acquisition means for acquiring position information of the moving body from a GPS sensor, wherein the calculation means is the first position and the second position acquired by the position information acquisition means. An azimuth angle of the target is calculated based on position information.
According to such a configuration, even when the moving body moves on a complicated route, angle correction can be performed.

Further, the present invention has an orientation information acquisition means for acquiring orientation information from a magnetic orientation sensor,
The calculation means calculates the azimuth angle of the target based on the position information at the first position and the second position acquired by the position information acquisition means and the direction information acquired by the direction information acquisition means. It is characterized by calculating.
According to such a configuration, angle correction can be performed even when the moving body rotates.

The present invention also provides a radar apparatus correction method for detecting a target that is mounted on a moving body and that detects a azimuth angle of the target based on a reflection signal by transmitting a signal to the target. The target at the first position based on the positional relationship between the target and the moving body in the step, when the moving body is at the first position, and when the moving body is at a second position different from the first position. When the calculation step for calculating the azimuth angle of the target is different from the azimuth angle of the target detected by the detection step at the first position and the azimuth angle calculated by the calculation step, the detection step And a correction step of correcting the azimuth angle to be detected.
According to such a method, angle correction can be reliably performed with a simple configuration.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the radar apparatus and the correction method of a radar apparatus which can perform angle correction reliably with a simple structure.

It is a figure which shows the structural example of the radar apparatus which concerns on 1st Embodiment of this invention. FIG. 2 is a diagram illustrating a detailed configuration example of a control / processing unit illustrated in FIG. 1. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. It is a flowchart for demonstrating an example of the process performed in FIG. It is a figure which shows the structural example of the radar apparatus which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. It is a figure for demonstrating operation | movement of the radar apparatus shown in FIG. It is a flowchart for demonstrating an example of the process performed in FIG.

  Next, an embodiment of the present invention will be described.

(A) Description of Configuration of First Embodiment of the Present Invention FIG. 1 is a diagram illustrating a configuration example of a radar apparatus according to the first embodiment of the present invention. As shown in this figure, the radar apparatus 1 according to the first embodiment of the present invention includes a local oscillation unit 10, a transmission unit 11, a control / processing unit 15, a reception unit 16, and an A / D (Analog to Digital). The conversion unit 21 is a main component.

  Here, the local oscillation unit 10 generates a CW (Continuous Wave) signal having a predetermined frequency and supplies it to the transmission unit 11 and the reception unit 16.

  The transmission unit 11 includes a modulation unit 12 and a transmission antenna 13. The CW signal supplied from the local oscillation unit 10 is pulse-modulated by the modulation unit 12 and transmitted to the target via the transmission antenna 13. To do.

  The modulation unit 12 of the transmission unit 11 is controlled by the control / processing unit 15 to pulse-modulate the CW signal supplied from the local oscillation unit 10 and output the CW signal. The transmission antenna 13 transmits the pulse signal supplied from the modulation unit 12 toward the target.

  The control / processing unit 15 controls the local oscillation unit 10, the modulation unit 12, the antenna switching unit 18, and the variable gain amplification unit 19, and performs arithmetic processing on the received data supplied from the A / D conversion unit 21. To detect the target.

  FIG. 2 is a block diagram illustrating a detailed configuration example of the control / processing unit 15 illustrated in FIG. 1. As shown in FIG. 2, the control / processing unit 15 includes a control unit 15a, a processing unit 15b, a detection unit 15c, and a communication unit 15d. Here, the control unit 15a includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and each unit of the apparatus based on data stored in the ROM and the RAM. To control. The processing unit 15b is configured by, for example, a DSP (Digital Signal Processor) or the like, and executes processing on the digital signal supplied from the A / D conversion unit 21. The detection unit 15c is configured by, for example, a DSP and executes processing for detecting a target. The communication unit 15d notifies the detection result of the detection unit 15c to an external device.

  Returning to FIG. The receiving unit 16 includes a first receiving antenna 17-1 to an Nth receiving antenna 17 -N (N ≧ 2), an antenna switching unit 18, a variable gain amplifying unit 19, and a demodulating unit 20. A signal transmitted and scattered by the target is received and demodulated, and then output to the A / D converter 21.

  The first receiving antenna 17-1 to the Nth receiving antenna 17-N of the receiving unit 16 are configured by N antenna elements, receive a signal transmitted from the transmitting antenna 13 and scattered by a target, and perform antenna switching. Supply to unit 18. Note that the first receiving antenna 17-1 to the Nth receiving antenna 17-N are arranged at regular intervals in the horizontal direction, for example, and a target exists from the phase difference of reflected waves incident on these antennas. The azimuth angle to be detected can be detected.

  The antenna switching unit 18 is controlled by the control unit 15a of the control / processing unit 15, selects any one of the first reception antenna 17-1 to the Nth reception antenna 17-N, and variably amplifies the reception signal. Supplied to the unit 19. The gain variable amplification unit 19 is controlled in gain by the control unit 15 a of the control / processing unit 15, amplifies the reception signal supplied from the antenna switching unit 18 with a predetermined gain, and outputs the amplified signal to the demodulation unit 20. The demodulator 20 demodulates the received signal supplied from the variable gain amplifier 19 using the CW signal supplied from the local oscillator 10 and outputs the demodulated signal.

  The A / D converter 21 samples the received signal supplied from the demodulator 20 at a predetermined cycle, converts it into a digital signal, and supplies the digital signal to the controller / processor 15.

(B) Description of Operation of First Embodiment of the Invention Next, operation of the first embodiment of the present invention will be described. FIG. 3 is a diagram for explaining the outline of the operation of the first embodiment. While the vehicle on which the radar device 1 is mounted is traveling, for example, a distance d to a predetermined position Pt of a roadside object (guard rail in the example of FIG. 3) is detected. Next, it is assumed that the vehicle travels straight by a predetermined distance D. The travel distance D can be obtained from the speed of the vehicle and the elapsed time.

  Next, the radar apparatus 1 calculates the angle θ by applying the distance d to the guardrail and the moving distance D to the following equation (1) as shown in a simplified manner in FIG. In FIG. 4, a broken-line rectangle indicates the position of the radar device 1 before movement, and a solid-line rectangle indicates the position of the radar device 1 after movement.

θ = arctan (d / D) (1)

  Next, the radar apparatus 1 detects an angle of the roadside object to a predetermined position Pt. More specifically, the radar apparatus 1 transmits, for example, a pulse-shaped transmission signal from the transmission antenna 13, and the reflected waves scattered by the roadside objects are converted into the first reception antenna 17-1 to the Nth reception antenna 17-. Receive by N.

  The antenna switching unit 18 selects any one of the first reception antenna 17-1 to the Nth reception antenna 17 -N and supplies it to the variable gain amplification unit 19. The variable gain amplifier 19 amplifies the received signal and supplies it to the demodulator 20.

  The demodulator 20 demodulates the received signal (for example, down-converts) based on the local oscillation signal supplied from the local oscillator 10 and supplies the demodulated signal to the A / D converter 21.

  The A / D converter 21 converts the signal output from the demodulator 20 into a digital signal and outputs the digital signal. The control / processing unit 15 processes the digital signal supplied from the A / D conversion unit 21 by the processing unit 15b, and executes a process in which the detection unit 15c detects the target. More specifically, the detection unit 15c is based on the phase difference of the received signal between the transmission and reception sequences by the combination of the transmission antenna 13 and each of the first reception antenna 17-1 to the Nth reception antenna 17-N. Is detected.

  Here, it is assumed that the azimuth angle detected by the radar apparatus 1 is θ1, and the azimuth angle detected based on the calculation according to FIG. 4 is θ2. At this time, if θ1 = θ2, since there is no detection error related to the azimuth angle, no correction is performed. However, if θ1 ≠ θ2, a detection error has occurred. In this case, the angle table is corrected to detect the azimuth angle. Thereby, an azimuth angle detection error can be corrected.

  According to the above processing, the detection error of the azimuth can be corrected using the roadside object. For this reason, since the speed of the target is not used, calculation errors can be reduced.

  Next, an example of processing executed in the first embodiment of the present invention will be described with reference to the flowchart shown in FIG. When the processing of the flowchart shown in FIG. 5 is started, the following steps are executed.

  In step S10, the control unit 15a transmits a transmission signal, receives a reflected wave reflected by a roadside object as a target, and detects a distance d to the target by the processing unit 15b and the detection unit 15c. Execute.

  In step S11, the control unit 15a calculates the moving distance by referring to the vehicle speed signal and time from the vehicle, determines whether or not the vehicle has moved the distance D, and determines that the distance D has been moved. In step S11: Y, the process proceeds to step S12. In other cases (step S11: N), the same processing is repeated.

  In step S12, the detection unit 15c detects the azimuth angle θ1 of the target. More specifically, the control unit 15a controls the modulation unit 12 to transmit a transmission signal from the transmission antenna 13, and the reflected waves reflected by the target are transmitted from the first reception antenna 17-1 to the Nth reception antenna 17-N. Receive by either. Then, the azimuth angle θ1 of the target is detected based on the phase difference of the received signal from the transmission / reception sequence by the combination of the transmission antenna 13 and the first reception antenna 17-1 to the Nth reception antenna 17-N.

  In step S13, the control unit 15a calculates the azimuth angle θ2 of the target by the above-described equation (1) based on the distance d to the target detected in step S10 and the movement distance D detected in step S11. To do.

  In step S14, the control unit 15a determines whether or not the azimuth angle θ1 detected in step S12 is equal to the azimuth angle θ2 calculated in step S13. If it is determined that they are equal (step S14: Y). The process ends, and otherwise (step S14: N), the process proceeds to step S15.

  In step S15, the control unit 15a executes a process of correcting the angle table stored in the detection unit 15c, for example.

  According to the above processing, the azimuth angle detection error can be corrected based on the roadside object.

  In the above processing, the distance D is fixed, but by making this distance D variable, errors in azimuth angles can be verified for various azimuth angles, and errors can be corrected as necessary. it can.

(C) Description of Configuration of Second Embodiment of the Present Invention FIG. 6 is a diagram illustrating a configuration example of the second embodiment of the present invention. In FIG. 6, compared with the first embodiment shown in FIG. 1, a GPS (Global Positioning System) sensor 31 and a magnetic direction sensor 32 are added. Other configurations are the same as those in FIG.

  Here, the GPS sensor 31 detects the position (latitude and longitude) of the host vehicle and supplies the detected position to the control / processing unit 15. The magnetic direction sensor 32 detects the direction of the host vehicle based on the geomagnetism and supplies the detected direction to the control / processing unit 15.

(D) Description of Operation of Second Embodiment of the Invention Next, with reference to FIGS. 7 and 8, the operation of the second embodiment shown in FIG. 6 will be described.

  As shown in FIG. 7, in the second embodiment of the present invention, the radar apparatus 1 detects the position P1 (x1, y1) of the own vehicle with reference to the output of the GPS sensor 31 at a certain point. The radar apparatus 1 transmits a radio wave to the roadside object, detects a distance d from the reflected wave to a specific part of the roadside object, and based on these, the position Pt (xt of the specific part of the roadside object , Yt) = P1 (xt-d, yt) is detected.

  Next, the control unit 15a of the radar apparatus 1 refers to, for example, the detection value of the vehicle speed sensor and the elapsed time, determines whether the vehicle has traveled a predetermined distance, and determines that the vehicle has traveled the predetermined distance. In such a case, the position P2 (x2, y2) of the host vehicle is detected with reference to the output of the GPS sensor 31.

  In the example of FIG. 7, the vehicle is traveling straight and the traveling direction of the vehicle is not changed, but actually, the vehicle is meandering or the traveling direction is changed. Therefore, it is assumed that the state at the positions P1 and P2 is FIG.

  In the example of FIG. 8, the vehicle is traveling not diagonally but diagonally, and the angle of the radar apparatus 1 is also changing (in FIG. 8, it is rotating counterclockwise).

  In such a case, the radar apparatus 1 uses FIG. 8 based on the following equation (2) from the target position Pt (xt, yt) and the position P2 (x2, y2) of the host vehicle at that time. The indicated angle θt is obtained. Note that θt is an angle between a reference direction (north direction in the example of FIG. 8) and the target direction.

θt = arctan ((xt−x2) / (yt−y2)) (2)

  Next, the radar apparatus 1 refers to the output of the magnetic direction sensor 32 and calculates the angle θv between the normal direction N of the radar apparatus 1 and the reference direction. More specifically, the magnetic azimuth sensor 32 outputs an angle θn with respect to the direction of true north, so that θn can be set to θv. Then, an azimuth angle θ1 (= θv + θt) between the target (a specific part of the roadside object in the example of FIG. 8) and the normal direction of the radar apparatus 1 is calculated from these θv and θt.

  Subsequently, the radar apparatus 1 controls the transmission unit 11 to transmit a transmission signal, and detects the azimuth angle θ2 of the target based on the reflected wave.

  Next, the radar apparatus 1 compares θ1 and θ2, and if they are not equal to each other, executes a process of correcting the angle table on the assumption that there is an azimuth angle detection error. This eliminates the azimuth angle error.

  As described above, according to the second embodiment of the present invention, the azimuth angle error can be corrected even when the vehicle does not go straight or when the vehicle rotates.

  Next, processing executed in the second embodiment will be described with reference to FIG. When the process shown in FIG. 9 is started, the following steps are executed.

  In step S30, the radar apparatus 1 detects the position P1 (x1, y1) of the host vehicle. More specifically, the control / processing unit 15 of the radar apparatus 1 refers to the output of the GPS sensor 31 and detects the position P1 (x1, y1) of the host vehicle.

  In step S31, the radar apparatus 1 detects a distance d to a predetermined position of a roadside object as a target. More specifically, the control unit 15a of the radar apparatus 1 controls the transmission unit 11 to transmit a transmission signal, receives a reflected wave from the target, and performs processing by the processing unit 15b and the detection unit 15c to perform the target. Until the distance d is detected.

  In step S32, the control unit 15a determines the target position Pt (xt, yt) based on the position P1 (x1, y1) of the host vehicle specified in step S30 and the distance d to the target detected in step S31. ) Is detected. For example, in the example of FIG. 7, the position of the target is specified by Pt (xt, yt) = P1 (x1−d, y1).

  In step S33, the control unit 15a stores the target position Pt (xt, yt) specified in step S32.

  In step S34, the control unit 15a determines whether or not the predetermined distance has been moved. If it is determined that the predetermined distance has been moved (step S34: Y), the process proceeds to step S35, and otherwise ( In step S34: N), the same processing is repeated. For example, referring to the vehicle speed detected by the vehicle speed sensor and the output from a timer (not shown), if it is determined that the vehicle has moved a predetermined distance, it is determined as Y and the process proceeds to step S35.

  In step S35, the control unit 15a detects the position P2 (x2, y2) of the host vehicle. More specifically, the control / processing unit 15 of the radar apparatus 1 refers to the output of the GPS sensor 31 and detects the position P2 (x2, y2) of the host vehicle.

  In step S36, the control unit 15a shows the position Pt (xt, yt) of the target and the position P2 (x2, y2) of the host vehicle at that time, based on the above-described equation (2), as shown in FIG. An angle θt is obtained.

  In step S <b> 37, the control unit 15 a refers to the output of the magnetic direction sensor 32 and calculates the angle θv between the normal direction N of the radar apparatus 1 and the reference direction.

  In step S38, the control unit 15a calculates the azimuth angle θ2 (= θt + θv) to the specific position of the roadside object detected in step S31 based on the angles θt and θv obtained in steps S36 and S37.

  In step S39, the control unit 15a detects the azimuth angle θ1 up to the specific position of the roadside object detected in step S31. More specifically, the control unit 15a of the radar apparatus 1 controls the transmission unit 11 to transmit a transmission signal, receives a reflected wave from the target, and performs processing by the processing unit 15b and the detection unit 15c to perform the target. Is detected.

  In step S40, the control unit 15a compares the azimuth angle θ1 detected in step S39 with the azimuth angle θ2 calculated in step S38, determines whether or not they are equal, and determines that they are equal (step S40). : Y), the process is terminated, and otherwise (step S40: N), the process proceeds to step S41.

  In step S41, the control unit 15a corrects the angle table stored in the detection unit 15c with the azimuth angle θ2 calculated in step S38.

  According to the above processing, the operation of the second embodiment described with reference to FIGS. 7 and 8 can be realized.

(I) Description of Modified Embodiment Each of the above embodiments is an example, and it is needless to say that the present invention is not limited to the case as described above. For example, in the configuration shown in FIG. 1 and FIG. 6, one transmission antenna 13 and N first reception antennas 17-1 to 17 -N are provided. If so, one receiving antenna and a plurality of transmitting antennas may be provided.

  In each of the above embodiments, the radar apparatus 1 disposed on the left rear side has been described as an example. However, for example, the roadside object disposed on the median strip is used to be disposed on the right rear side. You may make it correct | amend the error of the azimuth angle of the radar apparatus which is equipped.

  In addition, when two radar devices arranged on the left rear and right rear have detection areas overlapping each other, one radar device uses the target existing in the overlap detection area to The azimuth angle correction processing may be executed by the above-described method, and the obtained result may be supplied to the other radar device via a network or the like so that the other radar device corrects the azimuth angle.

  In each of the above embodiments, the correction process is executed when the vehicle has moved a predetermined distance. By changing this distance, the azimuth angle detected by the radar apparatus 1 is changed. Various azimuth angles may be corrected.

  Further, in each of the embodiments described above, the azimuth angle of the radar apparatus 1 disposed behind the vehicle is corrected. However, by performing the above-described process in reverse, the radar apparatus disposed in front of the vehicle is corrected. It is also possible to correct the azimuth.

  In each of the above embodiments, a guard rail is described as an example of a roadside object. However, other roadside objects (for example, traffic signs, utility poles, post boxes, etc.) may be used.

  5 and 9 are examples, and the present invention is not limited to the processes shown in these.

  In the configuration shown in FIG. 3, pulse signals are used for the types of signals transmitted from the transmission antenna 13, but FMCW (Frequency Modulated Continuous Wave) signals may be used.

  Further, in each of the above embodiments, the radar apparatus 1 transmits an electromagnetic wave to detect a target. However, other than this, for example, an optical signal, an ultrasonic wave, or the like may be used. .

  In the above embodiments, the radar apparatus 1 mounted on a vehicle has been described as an example. However, the present invention is applied to any radar apparatus mounted on a moving body that moves in the vicinity of a fixed object. be able to.

  In the example of FIG. 8, it is assumed that the radar device 1 rotates. However, when the radar device 1 does not rotate as shown in FIG. 4, that is, when the vehicle is traveling straight, the angle θv is measured. In such a case, the magnetic orientation sensor 32 can be omitted because it is not necessary.

DESCRIPTION OF SYMBOLS 1 Radar apparatus 10 Local oscillation part 11 Transmission part 12 Modulation part 13 Transmission antenna 15 Processing part 15a Control part 15b Processing part 15c Detection part 15d Communication part 16 Receiving part 17-1 to 17-N 1st receiving antenna-Nth receiving antenna DESCRIPTION OF SYMBOLS 18 Antenna switching part 19 Gain variable amplification part 20 Demodulation part 21 A / D conversion part 31 GPS sensor 32 Magnetic direction sensor

Claims (5)

In a radar device that is mounted on a moving object and detects a target,
Detecting means for transmitting a signal to the target and detecting an azimuth angle of the target based on a reflected signal;
The azimuth angle of the target at the first position based on the positional relationship between the target and the moving body when the moving body exists at the first position and when the moving body exists at a second position different from the first position. Calculating means for calculating
Correction means for correcting the azimuth angle detected by the detection means when the azimuth angle of the target detected by the detection means at the first position is different from the azimuth angle calculated by the calculation means; ,
A radar apparatus comprising:   The calculating means calculates an azimuth angle of the target based on a distance d between the target at the second position and a distance D between the first position and the second position. The radar apparatus according to claim 1. Position information acquisition means for acquiring position information of the mobile body from a GPS sensor;
2. The radar according to claim 1, wherein the calculation unit calculates an azimuth angle of the target based on position information at the first position and the second position acquired by the position information acquisition unit. apparatus. It has direction information acquisition means for acquiring direction information from a magnetic direction sensor,
The calculation means calculates the azimuth angle of the target based on the position information at the first position and the second position acquired by the position information acquisition means and the direction information acquired by the direction information acquisition means. The radar device according to claim 3, wherein the radar device is calculated. In a correction method for a radar device mounted on a moving body and detecting a target,
A detection step of transmitting a signal to the target and detecting an azimuth angle of the target based on a reflected signal;
The azimuth angle of the target at the first position based on the positional relationship between the target and the moving body when the moving body exists at the first position and when the moving body exists at a second position different from the first position. A calculating step for calculating
A correction step for correcting the azimuth angle detected by the detection step when the azimuth angle of the target detected by the detection step at the first position is different from the azimuth angle calculated by the calculation step; ,
A method for correcting a radar apparatus, comprising:

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