JP2008261887A - Axial deviation detection device of vehicular radar device, and its method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To correctly detect an axial deviation angle θ between a predetermined axis 7 and an axis 21 of vehicular linear running by running and deflecting a beam emitted for detecting a distance between detection objects 18 and 19 over both right and left sides of the predetermined axis 7 in a nearly-horizontal plane around a vertical axis 6. <P>SOLUTION: A radar means 25 is mounted on a vehicle 13, and its angular displacement is driven so that a beam from the radar means 25 is run by a drive means 5, and a reflected beam is received. While the vehicle 13 is running on a left running lane 16 of a linear road, a linear guard rail 18 arranged on the left road side is detected multiple times different in scanning angles ψ on the left side of the predetermined axis 7, virtual lines yLa and yRa connecting the respective multiple detection positions are calculated and obtained, and an axial deviation angle θ corresponding to a gradient k thereof is calculated and obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an axis deviation detection device for a vehicular radar device, and in particular, is mounted on a vehicle such as an automobile, and a beam such as a high-frequency signal beam or a laser beam in a millimeter wave band is vertically vertical in a substantially horizontal plane. The present invention relates to an axis misalignment detection apparatus for a vehicular radar apparatus that scans with an angular displacement about the axis of the vehicle and measures the distance to a detected object.

  In such a so-called scanning-type vehicular laser apparatus, the beam scanning angle φ must be accurately detected with respect to the axis of the vehicle in the linear travel direction. Otherwise, it is impossible to accurately detect the position of the detected object corresponding to the measured distance and the angle φ around the vertical axis that is the center of beam scanning. Therefore, when the beam angle φ with respect to the axis of the vehicle in the straight traveling direction cannot be accurately detected, the position of the detected object is erroneously detected. Therefore, it is necessary to correct or adjust so as not to cause an axis deviation. In a state where the radar apparatus is mounted on the vehicle, the mounting state of the radar apparatus on the vehicle may change due to vibration or secular change, which may cause an axis deviation.

  Conventionally, there has not been proposed a configuration that can easily detect such a shaft misalignment at all times, particularly even when the vehicle is running.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an axis deviation detecting device and method for a vehicular radar apparatus that can easily detect an axis deviation of an angle φ of a beam to be scanned with respect to an axis in a linear running direction of the vehicle even while the vehicle is running. Is to provide.

The present invention (1) is provided in a vehicle, emits a beam toward the front, receives a reflected beam from the detected object, and detects a distance from the detected object;
Driving means for driving the radar means to be angularly displaced around a vertical angular displacement axis within a predetermined angular displacement range 8 and over at least both sides of the predetermined axis 7 in the beam radiation direction within the angular displacement range;
Angle detection means for detecting the angle by the drive means of the radar means,
The radar means is a shaft misalignment detection device for a vehicle radar device that detects distances on both sides of the angular displacement range.
An axis deviation detection device for a radar device for a vehicle, comprising angle difference calculation means for calculating a difference θs between detection angles φL and φR by angle detection means corresponding to the same distance on the left and right.

Further, the present invention (2) is provided in a vehicle, emits a beam toward the front, receives a reflected beam from the detected object, and determines the distance between the detected object and the vertical angular displacement axis. In the method of detecting an axis deviation of the radar apparatus, which respectively detects at least both sides of the predetermined axis 7 in the beam radiation direction within the predetermined angular displacement range 8,
The radar apparatus is angularly driven around the vertical angular displacement axis within the predetermined angular displacement range 8 and over at least both sides of the predetermined axis 7 in the beam radiation direction within the angular displacement range,
Detect the angle φ by the angular displacement drive of the radar device,
A method for detecting an axis deviation of a vehicular radar apparatus, wherein a difference θs between detection angles φL and φR corresponding to the same distance on the left and right obtained by detecting the angle is calculated.

  According to the present invention (1) and (2), as will be described later with reference to FIGS. 11 to 13, the radar means provided in the vehicle is angularly displaced, for example, around a vertical axis 6 that is vertical. The beam is scanned and deflected in a horizontal plane, for example, and within a range of angular displacement in which the scanning is performed, the distance between the object to be detected is determined at least once on both the left and right sides with respect to a predetermined axis 7 in the beam radiation direction, for example, multiple times. Detect each. A difference θs between the angles φL and φR corresponding to the same distance on the left and right is calculated by an angle difference calculating means. Thus, the axis deviation angle θ (= θs / 2) can be detected.

  According to the present invention (1), (2), the distance between the object to be detected is determined at least once on the left and right sides with respect to the predetermined axis 7 in the beam radiation direction, that is, at least once on the left side and at least once on the right side. Detecting the angle represented by the output of the angle detection means corresponding to the distance and thus calculating the difference θs between the angles φL and φR corresponding to the same distance on the left and right to detect the axis deviation angle θ Will be able to.

  FIG. 1 is a block diagram showing the overall electrical configuration of an embodiment of the present invention. A sensor device 2 of a scanning FM-CW (Frequency Modulation-Continuous Wave) radar device 1 is mounted on a vehicle such as an automobile, and a transmitting antenna 3 transmits a high-frequency signal beam or laser beam in the millimeter wave band in front of the vehicle. A beam is emitted. The reflected beam from the detected object is received by the receiving antenna 4. This sensor device 2 is connected to the drive means 5.

  FIG. 2 is a simplified perspective view showing the configuration of the sensor device 2, the driving means 5, and the vicinity thereof. In the sensor device 2, the angular displacements of the maximum angles φaL and φaR around the substantially vertical vertical angular displacement axis 6 over at least one of the left and right sides of the predetermined axis 7 in the beam radiation direction (both left and right in this embodiment). Drive angular displacement within the range. For example, φaL = φaR = 5 degrees. The angular displacement range over the left and right maximum angles φaL and φaR with respect to the predetermined axis 7 is indicated by reference numeral 8. An angle φi related to the axis 7 within the angular displacement range 8 by the driving means 5 of the sensor device 2 is detected by the angle detecting means 11. The angle detection means 11 may be realized by a potentiometer, for example. The angular displacement range 8 exists in a substantially horizontal plane perpendicular to the vertical axis 6.

  The sensor device 2, the driving means 5, the angle detecting means 11, and the like are integrally attached to the vehicle body of the vehicle via the adjusting means 12. The adjusting means 12 can adjust the attitude of the sensor device 2, the driving means 5, the angle detecting means 11 and the like attached to the vehicle by an electric signal. For example, the adjusting means 12 adjusts by angular displacement in a horizontal plane. The adjusting means 12 may be configured such that the mounting posture is changed and adjusted manually by the operator.

  FIG. 3 is a plan view showing a state in which the vehicle 13 that is an automobile is traveling on the straight road 14. The road 14 has travel lanes 16 and 17 on the left and right of a center line 15 such as a white line. Along the traveling lanes 16 and 17, guard rails 18 and 19 that are horizontally extended and are stationary objects are installed on the roadside. The angular displacement range in a state where the sensor device 2 does not cause an axial deviation is indicated by a reference symbol 8a, and a state where the axial deviation occurs at a right side is indicated by a reference symbol 8b.

  The axis deviation means a state where the axis deviation angle θ formed by the predetermined axis 7 in the beam radiation direction within the angular displacement range 8 and the axis 21 in the linear travel direction of the vehicle 13 is not zero. That is, in the configuration in which the angle detection means 11 is realized by, for example, a potentiometer, when the output voltage corresponding to the detection angle φ is represented by a linear line, the voltage V7 corresponding to the angle of the axis 7 in the beam radiation direction When the voltage V21 corresponding to the axis 21 of the vehicle 13 does not match, an axis deviation angle θ corresponding to the voltage difference ΔV (= V7−V21) is generated. Therefore, by correcting the output voltage V of the angle detection means 11 by recalculating it to (V + ΔV), the actual angle φ at which the beam is emitted can be accurately detected from the output of the angle detection means 11. become. In a state in which such an axis deviation occurs, the relative detection position of the vehicle 13 calculated by the distance of the other vehicle existing in front of the vehicle 13 and the distance of the guard rails 18 and 19 and the angle by the angle detection means 11. Cannot be obtained accurately. In the present invention, the axis deviation angle θ can be accurately and automatically detected, and the detection angle φ by the angle detection means 11 is corrected or adjusted so that the axis deviation angle θ becomes zero. Means 12 operates. For example, when the detection angle φ of the angle detection means 11 corresponding to the axis 7 has a positive axis deviation angle θ on the right or on the left that is an error with respect to the axis 21 of the vehicle 13, the angle detection means 11. Is corrected to (φ + θ).

  The output derived from the sensor device 2 to the line 23 is given to a processing circuit 24 realized by a microcomputer or the like, whereby the distance and the relative velocity are measured by the FM-CW radar method. The sensor device 2 and the processing circuit 24 constitute a radar means 25.

FIG. 4 is a waveform diagram for explaining the operation for obtaining the distance to the object to be detected by the radar means 25 shown in FIG. FIG. 5 is a waveform diagram for explaining the operation of obtaining the relative speed with the detected object by the radar means 25 shown in FIG. Referring to these drawings, in sensor device 2 of radar means 25, modulation signal generator 27 generates a triangular wave having a frequency of, for example, 750 Hz and outputs a carrier wave signal having a high frequency in the millimeter wave band output from oscillator 28. Then, frequency-modulated (abbreviated as FM), and the resulting FM-modulated transmission signal 34 is radiated from the transmission antenna 3 toward the object to be detected. The received wave 35 of the reflected beam from the detected object is received by the receiving antenna 4 and given to the mixer 29. The mixer 29 is also supplied with a high frequency signal from an oscillator 28 via a directional coupler 31. The beat signal having the beat frequency fb from the mixer 29 is amplified by the amplifier 32 and supplied to the processing circuit 24 through the line 23 described above. The received wave 35 of the reflected beam from the detected object received by the receiving antenna 4 by the receiving antenna 4 changes in the distance frequency fr corresponding to the distance between the sensor device 2 and the detected object. As shown, the velocity frequency fd corresponding to the relative velocity with the detected object changes. The beat frequency fb of the beat signal derived from the mixer 29 is expressed by Equation 1.
fb = fr ± fd (1)

The modulation width of the modulation signal from the modulation signal generating circuit 27 is ΔΩ, the modulation wave period is T, c is the speed of light, R is the distance between the sensor device 2 and the detected object, and v is the detected object. And f0 is the transmission center frequency of the oscillator 28 that generates the carrier wave, Equations 2 and 3 hold.
fr = 4 · ΔΩ · T · R / c (2)
fd = 2 · f0 · v / c (3)

  Therefore, in the FM-CW radar system, the processing circuit 24 calculates and measures the distance R and the relative velocity v by obtaining the frequencies fr and fd based on the equations 2 and 3.

The processing circuit 24 is also given an output from the angle detection means 11 and further given outputs from the yaw rate sensor 36 and the acceleration sensor 37. The calculation result by the processing circuit 24 is displayed on the display means 38 such as a cathode ray tube or a liquid crystal. Memories 39 and 40 are connected to the processing circuit 24. The memory 39 is a writable nonvolatile memory, and can be realized by, for example, an EEPROM (Electrically Erasable Programmable Read only Memory). The memory 40 is realized by a random access memory, for example.

  FIG. 6 is a diagram showing a display state by the display means 38 when the sensor device 2 of the radar means 25 has no axis deviation. The predetermined axis 7 in the beam radiation direction by the sensor device 2 coincides with or is parallel to the axis 21 in the linear travel direction of the vehicle 13. While the vehicle 13 is traveling straight along the left lane 16 as shown in FIG. 3 described above, the beam detects the distance Ri a plurality of times on one side with respect to the axis 7a of the angular displacement range 8a, that is, on the left side. At this time, the angle detection means 11 detects the angle φi related to the axis 7a, and thus the coordinates (Ri, φi) of each detection position 41 of the left guard rail 18 are obtained. Among such a plurality of detection positions 41, for example, a virtual straight line yLa connecting the detection positions 42 that are the minimum value among the measurement distances R of the same angle φ by the angle detection means 11 is calculated and obtained by a least square method. . This virtual straight line yLa is obtained in a two-dimensional plane with the axis 21 of the vehicle 13 as the x-axis and the left-right width direction of the vehicle 13 perpendicular to the x-axis as the y-axis. During this traveling, or when the vehicle 13 is traveling straight along the right traveling lane 17 in the same direction as described above, when the right guardrail 19 is detected in the same manner as described above, the detected position 43 is obtained. Of these, it is also possible to obtain a virtual straight line yRa connecting the minimum detection positions 44 of each angle. In FIG. 6, the imaginary straight lines yLa and yRa are parallel to the x-axis, and their inclination k (see Equation 4 described later) is zero, and the axis deviation angle θ = 0.

  The subscripts a, b, and L included in the reference signs in the description of the present specification may be omitted and collectively shown.

  FIG. 7 is a diagram showing a display state of the display means 38 when the axis 7 b in the beam radiation direction by the sensor device 2 of the radar means 25 is misaligned with respect to the axis 21 of the vehicle 13. The axis 7b in the beam radiation direction is shifted to the right with respect to the axis 21 of the vehicle 13 in FIG. 7 by a non-zero axis deviation angle θ. While the vehicle 13 is traveling straight on the left lane 16 in FIG. 3, the detection position 45 of the left guardrail 18 is obtained, and thereby the detection position 46 of the minimum measurement distance for each of the plurality of angles detected by the angle detection means 11. A virtual straight line yLb connecting the two is obtained by the least square method, for example, as described above. As a result, the axis deviation angle θ can be obtained on the same two-dimensional screen as described above. Similarly, the virtual straight line yRb is obtained from the detection position 48 of the minimum distance among the detection positions 47 of the right guard rail 19 in the right travel lane 17, and the axis deviation angle θ is obtained.

When the virtual straight lines yLa and yRa of FIG. 6 obtained by the processing circuit 24 and the virtual straight lines yLb and yRb of FIG. 7 are generally represented by the reference symbol y, the expression of the primary straight line is expressed as follows: Is done.
y = kx + r (4)

The inclination k of the virtual straight line y corresponds to the axis deviation angle θ.
θ = tan ^-1 k (5)

  The processing circuit 24 responds to the outputs of the sensor device 2 and the angle detection means 11 as described above with reference to FIGS. 6 and 7 and the x-axis that is the axis 21 of the vehicle 13 and the x-axis. A distance is detected a plurality of times within an angular displacement range θaL extending at least on one side, for example, the left side with respect to the axis 7 in the beam radiation direction within a two-dimensional plane composed of the right and left y-axis of the vehicle 13 orthogonal to each other; Virtual straight lines yLa and yLb that connect a plurality of detection positions 42 and 46 having different detection angles φi detected by the angle detection means 11 can be calculated, and the axis deviation angle θ can be calculated and obtained from the inclination k. . When the right guard rail 19 is detected, the virtual straight lines yRa and yRb are obtained in the same manner as described above, and also at this time, the axis deviation angle θ can be obtained by calculation.

  FIG. 8 is a flowchart for explaining a specific operation of calculating the axis deviation angle θ by the processing circuit 24. When the processing circuit 24 determines that the power switch 51 shown in FIG. 1 has been turned on from the step u1 to the step u2, in step u3, the axis stored in advance from the writable nonvolatile memory 39. Read the deviation angle θ. In step u4, the electrical signal corresponding to the read axis deviation angle θ is given from the processing circuit 24 to the adjusting means 12, and the sensor device 2, the driving means 5 and the angle detection are performed so that the axis deviation angle θ becomes zero. The means 11 is adjusted for angular displacement. In another embodiment, the detection angle φ by the angle detection unit 11 may be corrected using the axis deviation angle θ read from the memory 39. The memory 39 stores the last axis deviation angle θ detected immediately before the power switch 31 is shut off, as will be described in connection with step u14 described later. The power switch 51 may be an accessory switch provided in association with the power source 52 of the ignition circuit for the internal combustion engine of the vehicle 13.

  In step u5, it is determined whether or not the vehicle 13 is traveling straight on the basis of the output of the yaw rate sensor 36. When traveling straight, the process proceeds to the next step u6. In step u6, it is determined whether the traveling speed v1 of the vehicle 13 detected by the vehicle speed sensor 53 is greater than or equal to a predetermined value v10 (v1 ≧ v10). This predetermined value v10 may be 60 km / h, for example. Thus, the axis deviation angle θ is detected while the vehicle 13 is traveling at a speed equal to or greater than the predetermined value v10. As a result, the axis 21 of the vehicle 13 and the predetermined axis 7 within the angular displacement range 8 of the beam by the sensor device 2 can be accurately matched during actual travel, and the axis deviation angle θ can be reliably reduced to zero. And will be able to.

  In step u7, the timer W1 is set to zero, and in the next step u8, the distance Ri to the detected object is calculated and obtained by the action of the sensor device 2. In step u9, the angle φi detected by the angle detection means 11 when this distance Ri is obtained is obtained. In step u10, the timer W1 is incremented by time ΔW1. When the measurement time of the timer W1 is represented by the same reference symbol, in step u11, it is determined whether the time of the timer W1 is equal to or greater than a predetermined time W10 (W1 ≧ W10). W10 may be, for example, 6 seconds. The measurement sampling time interval ΔW1 between the distance Ri and the angle θi may be 6 msec, for example. Based on the distance Ri and the angle θi obtained in this way, the virtual straight line y is obtained from the above-described equation 4 at, for example, every 2 minutes in u12 in the above-described two-dimensional plane. In step u13, the axis deviation angle θ is obtained from the inclination k of the virtual straight line y according to the above-described equation 5. The axis deviation angle θ thus obtained is written into the memory 39 by step u14. In step u15, the adjusting means 12 is operated and controlled so that the axis deviation angle θ obtained in step u13 described above becomes zero.

  In step u16, in response to the acceleration a1 along the traveling direction of the vehicle 13 detected by the acceleration sensor 37, it is determined whether the detected acceleration a1 is a predetermined value a10 or more (a1 ≧ a10). Is large, there is a high possibility that an axis deviation has occurred. When such acceleration is large, the process returns to step a8 again. In another embodiment of the present invention, steps u7 to u15 may be performed continuously and repeatedly.

  Whether or not the vehicle 13 is in the straight traveling state in the above-described step u5 is determined by the output of the yaw rate sensor 36 that detects turning around the vertical axis of the vehicle 13 in the above-described embodiment. In another embodiment, (1) the steering wheel angle or steering angle scanned by the driver of the vehicle 13 may be detected by a sensor, or (2) the vehicle 13 is mounted on the vehicle 13 and images a front scene. A TV camera may be provided to detect the straight running by processing the captured image. Furthermore, (3) a GPS (Global Positioning System) device that detects the running position of the vehicle 13 corresponds to the road map data. Further, it may be configured to detect linear travel, and (4) the linear travel may be detected by other configurations.

  FIG. 9 is a diagram showing an experimental result by the present inventor. The experimental result of FIG. 9 corresponds to FIG. The present inventor is represented by the black dots shown in FIG. 9 by running straight on the left lane 16 of the road 14 in the left and right lanes in the same running direction according to the above-described embodiment shown in FIGS. The detected position can be obtained. In FIG. 9, the virtual straight line yLb1 can be obtained by the least square method, and the axis deviation angle θ1 corresponding to the inclination k can be obtained. In FIG. 9, the axis deviation angle θ <b> 1 is, for example, less than 0.1 degree and a relatively small value, and the adjusting unit 12 does not have to perform a correction operation for axis deviation. Whether or not the axis deviation adjustment is performed by the adjusting means 12 is determined based on whether or not the virtual straight line yLb1 is equal to or greater than a predetermined position x1 on the x-axis that is the axis 21 when the vehicle 13 is traveling straight (above the position x1 in FIG. 9). When the virtual straight line yLb1 intersects the x axis at the position x1 or more, the axis deviation angle θ1 is a small value, and the adjustment means 12 It can be determined that it is not necessary to correct the axis deviation. When the virtual straight line yLb1 intersects the X axis with the X axis less than the position x1 (downward in FIG. 9), it is determined that the axis deviation angle θ1 is large and therefore the adjusting operation by the adjusting means 12 is necessary, and the adjusting operation is performed. Can be configured to do.

  In calculating the virtual straight line yLb1 in FIG. 9, in order to reduce the amount of calculation processing as much as possible, an area 55 including the position x1 is set in the two-dimensional plane shown in FIG. The virtual straight line yLb1 may be calculated using only the detection positions existing in the. As a result, the amount of calculation processing by the processing circuit 24 can be reduced as much as possible, and the virtual straight line yLb1 can be quickly obtained.

  FIG. 10 is a diagram showing another experimental result by the present inventors. The virtual straight line yLb2 obtained by the calculation intersects the x-axis that is the axis 21 of the vehicle 13 in a range less than the position x1, and therefore the axis deviation angle θ2 is relatively large, and the axis deviation adjustment operation by the adjusting means 12 is performed. Done. The other experimental conditions are the same as those of the experiment described with reference to FIG. The axis deviation angle θ2 is 2 degrees in the experiment of FIG.

  FIG. 11 is a simplified plan view showing a state in which the vehicle 13 is traveling straight on a straight road 56 according to another embodiment of the present invention. There are travel lanes 58 and 59 on the left and right sides of the travel lane 57 in which the vehicle 13 is traveling. Therefore, there are at least three lanes in total in the same travel direction on this road. Vehicles 61 and 62 are traveling in the same direction on the traveling lanes 58 and 59. The vehicle 13 is equipped with the axis deviation detecting device of the vehicle radar device according to the embodiment described in relation to FIGS. In this embodiment, when the vehicle 13 is traveling in a straight line on the travel lane 57, the axis deviation angle θ is detected by detecting the other vehicles 61 and 62 traveling on the left and right travel lanes 58 and 59. Can do. The vehicles 61 and 62 traveling in the left and right traveling lanes 58 and 59 have different traveling speeds from the vehicle 13. Therefore, the vehicles 61 and 62 are used by using a radar device mounted on the vehicle 13 a plurality of times. 62 is detected and handled as a detected object similar to the left and right guard rails 18 and 19 in the above-described embodiment, and the axis deviation angle θ can be calculated and obtained. This embodiment has a configuration similar to the above-described embodiment, and will be described using the same reference numerals.

  FIG. 12 is a diagram showing a state in which the calculation result of the processing circuit 24 is displayed on the two-dimensional display screen of the display means 28 in the embodiment of the present invention shown in FIG. The processing circuit 24 is a diagram showing the relationship between the distance R to the vehicles 61 and 62 that are detected objects and the detection angle φ by the angle detection means 11 based on the outputs of the sensor device 2 and the angle detection means 11. A line 64 is obtained by detecting the vehicle 61 traveling on the left traveling lane 58 with respect to the traveling lane 57 on which the vehicle 13 of the road 56 is traveling in a straight line, and the vehicle 62 traveling on the right lane 59 is also detected. A line 65 is obtained by detection. In each lane 58, 59, a plurality of vehicles 61, 62 travel in a predetermined time, for example, 20 minutes, and the speed of the vehicle 13 and the speed of the vehicle 61 are as described above. The processing circuit 24 in the shaft misalignment detection device mounted on the vehicle 13 detects the different vehicles 61 and 62 during the predetermined time with the passage of time while traveling on the lanes 58 and 59, thereby showing in FIG. The experimental result of each line 64, 65 is obtained. Each line 64 and 65 has a difference θs (= φL−φR) between angles L and φR at a predetermined distance R1. This angle difference θs corresponds to the above-described axis deviation angle θ (θ = θs / 2).

  FIG. 13 is a flowchart for explaining a partial operation of the processing circuit 24 in the embodiment shown in FIGS. 11 and 12. Steps h1 to h4 in FIG. 13 are executed in place of steps u8 to u13 in FIG. In step h1, in the same manner as in the above-described embodiment, the beam is radiated in front of the vehicle 13, and the reflected beam is received, so that each lane 58, The distances RiL and RiR to the vehicles 61 and 62 traveling 59 are calculated and obtained. In step h2, the angles φiL and φiR detected by the angle detection means 11 when these distances RiL and RiR are obtained are obtained. A plurality of combination data (RiL, φiL) and (RiR, φiR) of the left and right distances and angles obtained in this way are stored in the memory 40 for a predetermined time W10. In this way, lines 64 and 65 corresponding to the distance R and the angle φ shown in FIG. 12 are obtained.

  In step h3, an angle difference θs (= φiL−φiR) between the angles φiL and φiR at the same predetermined distance R1 is calculated and obtained. Thus, the axis deviation angle θ is calculated. In step h4, it is determined whether the time of the timer W1 is equal to or greater than a predetermined time W10 (W1 ≧ W10), and if so, the operations in step u14 and subsequent steps in FIG. 8 are executed. In another embodiment of the present invention, the vehicles 61 and 62 may travel in the opposite direction to the vehicle 13 in at least one of the travel lanes 58 and 59 in which the vehicle 13 travels. Furthermore, the vehicle 13 may remain stopped.

  In another embodiment of the present invention, when the detected axis deviation angle θ is equal to or greater than a predetermined value θ11, the operation of the axis deviation detection device is suspended. This value θ11 may be a value of 2 degrees or more, for example. The operator investigates the cause of the abnormally large axis deviation angle θ and performs repair.

  With respect to a signal corresponding to the reflected beam of the detected object supplied from the sensor device 2 to the processing circuit 24 via the line 23, the processing circuit 24 calculates the distance and relative velocity corresponding to the frequency of the maximum reception level of the signal. Alternatively, the reception level may be discriminated and the signal frequency when the reception level is a predetermined value or more may be calculated.

  The present invention is not limited to the above-described FM-CW radar system, and adopts a radar system having other configurations, and can be widely implemented in connection with a radar means for measuring a distance from a non-detected object. .

  In order to scan the beam radiated from the radar means with angular displacement, the radar means may be angularly displaced by a mechanical structure, or only the transmission antenna and the receiving antenna of the radar means are mechanically angularly displaced. Further, the angle of the transmitted wave and the received wave may be angularly displaced by an electrical method. For example, a phased array antenna is used as the transmitting antenna and the receiving antenna, and the radiation is radiated from each antenna element of the phased array antenna. Alternatively, the phase difference of the electromagnetic wave beam may be changed.

The following embodiments are possible for the present invention.
(1) Radar means that is provided in a vehicle, emits a beam toward the front, receives a reflected beam from the detected object, and detects a distance from the detected object;
Driving means for driving the radar means to move around the vertical angular displacement axis within the predetermined angular displacement range 8 and over at least one side of the predetermined axis 7 in the beam radiation direction within the angular displacement range;
Angle detecting means for detecting the angle φ by the driving means of the radar means,
The radar means is an axial deviation detection device for a vehicle radar device that detects a distance a plurality of times on the at least one side within an angular displacement range.
In response to the outputs of the radar means and the angle detection means, a virtual straight line connecting a plurality of detection positions having different detection angles φ of the detected object on at least one side of the predetermined axis is a straight line running of the vehicle An axis deviation detecting device for a vehicular radar apparatus, comprising: an axis deviation angle calculating means for calculating an axis deviation angle θ formed with a direction axis.

  As will be described later with reference to FIGS. 1 to 9, a radar means is provided on the body of a vehicle such as an automobile, and this radar means applies a high-frequency signal beam such as a millimeter wave band or a beam such as a laser beam to the vehicle. The reflected beam from the object to be detected, for example, a vehicle traveling in front of the traveling direction of the vehicle and a guardrail installed on the roadside of the road, is received, thereby Detect distance. The radar means is provided with a driving means, for example, within an angular displacement range φaL, φaR predetermined around a vertical longitudinal angular displacement axis 6, over at least one side of the predetermined axis 7 in the beam radiation direction, for example, on the left side or right side. It can be displaced and thus deflected by scanning the beam, for example in a substantially horizontal plane. The angle by the driving means of the radar means is detected by the angle detecting means. The radar means detects the distance a plurality of times on at least one side within the angular displacement range.

  In this way, with the vehicle traveling on a straight road and guardrails installed in a straight line along the road, the radar means is detected at the beam scanning position on the one side. The distance to the guardrail that is an object can be detected a plurality of times. Accordingly, the obtained virtual straight line yLa, yRa connecting the plurality of detection positions with different detection angles φ on the one side is calculated as an axis deviation angle θ formed with the axis 21 in the vehicle linear travel direction. As a result, during the straight traveling of the vehicle, the guard rail detected by the radar means and the axis of the vehicle in the straight traveling direction are parallel, so that the shaft misalignment angle θ is zero and no shaft misalignment occurs, or the shaft misalignment angle. It is possible to detect whether θ is a certain value that is not zero and an axis deviation occurs. The driving means may be configured to mechanically angularly displace the radar means, but may be configured to scan by a later-described phased array antenna that angularly displaces the beam radiation direction by an electrical method. Instead of the axis deviation angle θ, a value corresponding to the axis deviation angle θ may be used.

  When the shaft misalignment angle θ is not zero and therefore there is a shaft misalignment, the detection angle φ detected by the angle detecting means is corrected to (φ + θ) and used for detecting the position of the detected object, or described later. The adjusting unit 12 adjusts the mounting posture of the radar unit and the driving unit with the vehicle. As a result, the virtual straight line, and thus the predetermined axis 7 in the beam radiation direction, can virtually coincide with the axis 21 in the straight traveling direction of the vehicle. Accordingly, the position of the detected object can be accurately grasped based on the distance to the detected object existing in front of the vehicle and the angle φ of the scanning angular displacement.

  With respect to the axis 21 in the linear traveling direction of the vehicle, the axial deviation of the angle φ of the beam to be operated can be easily and automatically detected even while the vehicle is traveling. Therefore, even if the mounting posture of the radar unit or the like on the vehicle changes, the position of the detected object can be accurately detected by detecting the axis deviation. Such a vehicular radar device may perform a braking operation when the distance to the detected object becomes less than a predetermined value, and the distance from the vehicle traveling ahead is the same. It can be carried out to keep running.

(2) The axis deviation angle calculation means is:
A virtual straight line calculating means for calculating the virtual straight line in response to outputs of the radar means and the angle detecting means;
An axis deviation detecting device for a vehicular radar apparatus, comprising: means for calculating an axis deviation angle θ based on an inclination k of the virtual line in response to an output of the virtual line calculating means.

  The virtual straight line is calculated to obtain a linear function, and the axis deviation angle θ corresponding to the inclination k of the virtual straight line is calculated. Thus, the axis deviation angle θ can be easily obtained. The linear function of the virtual straight line may be obtained by calculation by the least square method based on the plurality of detection positions.

  A linear function that is a virtual straight line is obtained, and the axis deviation angle θ can be easily calculated and obtained.

(3) a straight running detection means for detecting that the vehicle is running straight;
An axis deviation detecting device for a vehicular radar apparatus, comprising: a linear running control means for operating the axis deviation angle calculating means only during linear running in response to an output of the linear running detecting means.

  Only when the straight running detection means detects that the vehicle is running straight, the straight running control means operates the axis deviation angle calculating means, whereby the axis deviation angle θ is calculated. In this way, it is possible to detect a detected object parallel to the road such as a guard rail installed on the road side of the straight road, and to accurately detect the axis deviation angle θ in the actual traveling state.

  Since the axis deviation angle θ is calculated and obtained only when the vehicle is traveling in a straight line, the axis deviation angle θ in the actual running state can be accurately detected.

(4) a memory for storing the axis deviation angle θ calculated by the axis deviation angle calculating means;
Output means for reading out and outputting the axis deviation angle θ stored in the memory during a period from when the power is turned on to when the axis deviation angle θ is calculated by the axis deviation angle calculating means. Axis deviation detector for radar equipment.

  The axis deviation angle stored in advance in the memory at least during the period from when the present axis deviation detection device is started up, that is, from when the power is turned on until the actual axis deviation angle θ is calculated by the axis deviation angle calculating means. Using θ, it is possible to correct the detection position of the detected object. This memory may store the detected shaft misalignment angle θ immediately before the time when the power of the present shaft misalignment detecting apparatus is turned off, and this memory may be realized by a non-volatile memory.

  The axis deviation angle θ stored in the memory is derived when the axis deviation detection device is started up, for example, during the period from when the power is turned on until the first axis deviation angle θ is calculated, thereby detecting the object to be detected. Can be accurately detected.

(5) an acceleration sensor for detecting acceleration acting on the vehicle;
An axis deviation detecting device for a radar apparatus for a vehicle, comprising: an acceleration control means for operating an axis deviation angle calculating means when the detected acceleration is equal to or greater than a predetermined value in response to an output of the acceleration sensor .

  The acceleration sensor detects, for example, the acceleration of the vehicle before and after the traveling direction, and when the detected acceleration is equal to or greater than a predetermined value and a relatively large impact force is applied to the vehicle, the axis deviation angle calculating means is operated. Then, a new axis deviation angle θ is calculated and obtained. When a large impact force is applied to the vehicle, the radar means and the drive means attached to the vehicle may change the mounting posture relative to the vehicle. In such a case, the axis deviation angle θ is newly calculated. By re-doing, it is possible to always detect the actual accurate axis deviation angle θ.

  When the impact force greater than a predetermined value is applied to the vehicle by the acceleration sensor, the axis deviation angle θ is newly calculated, so that the actual accurate axis deviation angle θ can always be detected.

  (6) The axis deviation detection device for a vehicular radar apparatus, wherein the driving means drives the radar means to be angularly displaced over both sides of the predetermined axis 7 within the angular displacement range.

  The beam by the radar means is angularly driven over both the left and right sides of the predetermined axis 7 within the angular displacement range, whereby the detected object can be detected over a relatively wide range in front of the vehicle.

  The beam by the radar means is scanned by angular displacement driving on both the left and right sides of the axis 7, so that the detected object can be detected over a relatively wide range in front of the vehicle.

  (8) An axis misalignment detection apparatus for a radar apparatus for a vehicle, comprising an adjustment means for adjusting a posture in which the radar means and the driving means are integrally attached to the vehicle.

  The radar unit and the driving unit can be integrated, and the attitude attached to the vehicle can be adjusted by the adjusting unit. Thus, the axis deviation angle θ can be adjusted to be zero. The adjusting means may be configured such that the operator manually adjusts the mounting posture, but may be configured to automatically adjust the mounting posture in response to an electrical signal.

  Adjustment can be made so that the axis deviation angle θ becomes zero, and the position of the detected object can be accurately detected.

(9) an adjusting means for adjusting the posture of attaching the radar means and the driving means integrally to the vehicle;
In response to the output of the axis deviation angle calculation means,
And adjusting driving means for driving the adjusting means so that the axis deviation angle θ becomes zero.

(10) Adjustment means for adjusting a posture of attaching the radar means and the drive means integrally to the vehicle;
An axis deviation detection device for a vehicular radar apparatus, comprising: an adjustment drive unit that drives the adjustment unit so that the difference θs between the angles φL and φR becomes zero in response to an output of the angle difference calculation unit.

  The adjusting means for adjusting the attitude at which the radar means and the driving means are integrally attached to the vehicle is driven by the adjusting driving means so that the axis deviation angle θ or the angle difference θs corresponding to the axis deviation angle θ becomes zero. Control. In this way, the predetermined axis within the angular displacement range of the beam can be automatically made to always coincide with the axis of the straight running of the vehicle.

  It is possible to calculate the axis deviation angle θ or the corresponding angle difference θs, drive the adjustment means by the adjustment drive means so as to eliminate the axis deviation, and thus accurately detect the position of the detected object.

1 is a block diagram showing an overall electrical configuration of an embodiment of the present invention. It is the simplified perspective view which shows the structure of the sensor apparatus 2, the drive means 5, and its vicinity. 2 is a plan view showing a state in which a vehicle 13 that is an automobile is traveling on a straight road 14. FIG. It is a wave form diagram for demonstrating the operation | movement which calculates | requires the distance between to-be-detected objects by the radar means 25 shown by FIG. It is a wave form diagram for demonstrating the operation | movement which calculates | requires the relative velocity with a to-be-detected object by the radar means 25 shown by FIG. It is a figure which shows the display state by the display means 38 when the sensor apparatus 2 of the radar means 25 has not produced the axial shift. FIG. 7 is a diagram showing a display state of the display means when the axis line 7b in the beam radiation direction by the sensor device 2 of the radar means 25 has an axis shift with respect to the axis line 21 of the vehicle 13. 6 is a flowchart for explaining a specific operation for calculating an axis deviation angle θ by the processing circuit 24; It is a figure which shows one experimental result by this inventor. It is a figure which shows the other experimental result by this inventor. It is the simplified top view which shows the state in which the vehicle 13 is running on the straight road 56 in the other form of implementation of this invention on a straight line. In the embodiment of the present invention shown in FIG. 11, the calculation result of the processing circuit 24 is displayed on the two-dimensional display screen of the display means 28. 13 is a flowchart for explaining an operation of a part of the processing circuit 24 in the embodiment shown in FIGS. 11 and 12.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Axial deviation detection apparatus of vehicle radar apparatus 2 Sensor apparatus 3 Transmission antenna 4 Reception antenna 5 Driving means 6 Vertical axis 7, 7a, 7b Predetermined axis of beam radiation direction 8 Angular displacement range 11 Angle detection means 12 Adjustment means 13 Vehicle 14 Road 21 Axis line of vehicle 13 in straight running direction 24 Processing circuit 25 Radar means 36 Yaw rate sensor 37 Acceleration sensor 38 Display means 39, 40 Memory 51 Power switch 53 Vehicle speed sensor φ Detection angle θ Axis deviation angle yLa, yRa, yLb, yRb virtual straight line

Claims (2)

Radar means provided in the vehicle, radiating a beam toward the front, receiving a reflected beam from the detected object, and detecting a distance from the detected object;
Driving means for driving the radar means to be angularly displaced around a vertical angular displacement axis within a predetermined angular displacement range 8 and over at least both sides of the predetermined axis 7 in the beam radiation direction within the angular displacement range;
Angle detection means for detecting the angle by the drive means of the radar means,
The radar means is a shaft misalignment detection device for a vehicle radar device that detects distances on both sides of the angular displacement range.
An axis deviation detection device for a radar device for a vehicle, comprising angle difference calculation means for calculating a difference θs between detection angles φL and φR by angle detection means corresponding to the same distance on the left and right. Provided in the vehicle, emits a beam toward the front, receives a reflected beam from the detected object, and determines the distance to the detected object within a predetermined angular displacement range 8 around the vertical angular displacement axis. In a method for detecting an axis deviation of a radar apparatus for detecting at least both sides of a predetermined axis 7 in the beam radiation direction of
The radar apparatus is angularly driven around the vertical angular displacement axis within the predetermined angular displacement range 8 and over at least both sides of the predetermined axis 7 in the beam radiation direction within the angular displacement range,
Detect the angle φ by the angular displacement drive of the radar device,
A method of detecting an axis deviation of a vehicular radar apparatus, wherein a difference θs between detection angles φL and φR corresponding to the same distance on the left and right obtained by detecting the angle is calculated.

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