JP2011164989A - Apparatus for determining unstable state - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an unstable-state determination device that enhances accuracy in determining unstable-state of a vehicle around a vehicle without narrowing a detection area of the vehicle around the vehicle. <P>SOLUTION: The unstable-state determination device 70 includes: a first computing means 20 that obtains a first position information (distance, lateral position) of the vehicles around the vehicle, the information being detected by a first detection means 20; a second computing means 30 that obtains a second position information (distance, lateral position) of the vehicles around the vehicle, the information being detected by a second detection means 30 whose detection principle is different from that of the first detection means 20; an integrated computing means 74 that obtains integrated position information (distance, lateral position) of the vehicles around the vehicle by integrating the first and second position information; a selection means 75 that selects any of the first and second position information and the integrated position information based on the location of the vehicles around the vehicle; and a determination means 76 that determines an unstable-state of the vehicles around the vehicle, based on temporal change of the selected position information (distance, lateral position). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wobble determination device that performs a wobble determination of surrounding vehicles.

  Patent Document 1 includes a wobbling determination device (vehicle running state detection device) that performs a wobbling (unstable degree) determination of a preceding vehicle, and a driving support device (vehicle driving control device) that performs driving support according to the determination result. Is disclosed. The wobbling determination device detects the horizontal position of the preceding vehicle in the horizontal direction by capturing an image ahead of the host vehicle with a CCD camera and performing image processing. In this wobbling determination device, the change pattern is detected by following the lateral position of the preceding vehicle in time, and the wobbling of the preceding vehicle is determined from this change pattern.

JP 2004-220348 A

  However, in the wobbling determination based only on the change in the lateral position of the preceding vehicle, the determination accuracy is low. In this regard, in addition to the change in the horizontal position, by performing the wobble determination based on the change in the vertical position of the preceding vehicle in the front-rear direction, that is, the change in the distance between the host vehicle and the preceding vehicle, It can be raised.

  However, in the detection by the camera, the detection accuracy of the lateral position is relatively high, but the detection accuracy of the distance from the preceding vehicle is low. In this regard, it is conceivable to use a millimeter wave radar instead of the camera. However, in the detection by the millimeter wave radar, the detection accuracy of the distance to the preceding vehicle is relatively high, but the detection accuracy in the lateral direction is low. For this reason, it has been difficult to improve the accuracy of detection of wobbling of the preceding vehicle.

  In this regard, the inventors have devised a technique called sensor fusion. Sensor fusion uses two sensors with different detection principles, for example, a millimeter wave radar and a camera. The distance from the highly accurate preceding vehicle detected by the millimeter wave radar and the lateral position of the highly accurate preceding vehicle detected by the camera. It is a technique to fuse (fusion). As a result, both the distance from the preceding vehicle and the lateral position of the preceding vehicle can be detected with high accuracy.

  However, detection by millimeter wave radar generally has a narrow horizontal detection range due to limitations in horizontal resolution and antenna size, and detection by camera generally detects from the relationship between image accuracy, resolution, and ranging method. Since the distance is short, the range that can be detected by sensor fusion is narrow.

  In view of the above, an object of the present invention is to provide a wobbling determination device that can increase the accuracy of wobbling determination of surrounding vehicles without narrowing the detection range of the surrounding vehicles.

  The wobble determination device according to the present invention includes a first calculation unit that obtains a distance to a surrounding vehicle and a lateral position of the surrounding vehicle as first position information of the surrounding vehicle detected by the first detecting unit, Second computing means for determining a distance to the surrounding vehicle and a lateral position of the surrounding vehicle as second position information of the surrounding vehicle detected by the second detecting means using a detection principle different from the detecting means; Based on the fusion calculation means for obtaining the distance to the surrounding vehicle and the lateral position of the surrounding vehicle as the fused position information of the surrounding vehicle by fusing the second position information, the first and second Selection means for selecting any one of the position information and the fusion position information, the distance to the surrounding vehicle in the position information selected by the selection means, and the lateral position of the surrounding vehicle, respectively Based on the temporal variation comprises a judging means for performing wobble determination around the vehicle, a.

  According to the fluctuation determination device, detection is performed by fusing the first position information detected by the first detection means and the second position information detected by the second detection means by the fusion calculation means. It is possible to obtain the fusion position information having the distance to the surrounding vehicle with high accuracy and the lateral position of the surrounding vehicle with high detection accuracy. Therefore, the determination unit performs the wobble determination of the surrounding vehicle by performing the wobble determination of the surrounding vehicle based on the temporal variation of the distance to the surrounding vehicle and the temporal variation of the lateral position of the surrounding vehicle in the fusion position information. Accuracy can be increased.

  Further, according to this wobble determination device, when the position of the surrounding vehicle is within the undetectable area of one of the first and second detection means, that is, the fusion position information is obtained. If this is not possible, the position information of the other detection means can be selected by the selection means. Therefore, even when the fusion position information cannot be obtained, the determination means causes the time variation of the distance to the surrounding vehicle in the position information of any one of the first and second detection means and the surrounding vehicle. Based on the temporal variation of the lateral position, it is possible to perform the wobble determination of the surrounding vehicle. Therefore, according to this wobble determination device, the detection range of surrounding vehicles is not narrowed.

The above fusion calculation means includes distance detection accuracy ± Z _X1 and lateral position detection accuracy ± Z _Y1 by the first detection means, distance detection accuracy ± Z _X2 and lateral direction by the second detection means. based on the detection accuracy ± Z _Y2 position, lateral position Y ₁ of the first distance X ₁ and the peripheral vehicle and the peripheral vehicle in the position _information, the distance between the adjacent vehicle in the second location in the case of X ₂ and the peripheral vehicle is lateral position Y _2, it is preferable to determine the lateral position Y ₃ of the distance X ₃ and the peripheral vehicle and the peripheral vehicle in the fusion position information by the following equation.
X ₃ = (Z _X2 × X ₁ + Z _X1 × X ₂ ) / (Z _X1 + Z _X2 )
_{Y 3 = (Z Y2 × Y} 1 + Z Y1 × Y 2) / (Z Y1 + Z Y2)

  According to this, as described above, it is possible to obtain the fusion position information having the distance to the surrounding vehicle with high detection accuracy and the lateral position of the surrounding vehicle with high detection accuracy.

  Preferably, the first detecting means is a radar, and the second detecting means is a camera.

  In the detection by the radar, the detection accuracy of the distance to the surrounding vehicle is relatively high, and in the detection by the camera, the detection accuracy of the lateral position is relatively high. Therefore, according to this, it is possible to obtain fusion position information obtained by fusing the distance from the surrounding vehicle with high detection accuracy by the radar and the lateral position of the surrounding vehicle with high detection accuracy by the camera.

  Further, the first detection unit described above may be a millimeter wave radar, and the second detection unit described above may be a laser radar.

  Since the laser radar has a shorter wavelength than the millimeter wave radar, the lateral position detection accuracy is relatively high. Therefore, according to this, the fusion position information obtained by fusing the distance from the surrounding vehicle with high detection accuracy by the millimeter wave radar and the lateral position of the surrounding vehicle with high detection accuracy by the laser radar can be obtained by the fusion calculation means. it can.

  The selecting means selects the fusion position information when the surrounding vehicle is within the detectable range of the first and second detecting means, and the surrounding vehicle is outside the detectable range of the first detecting means. In this case, it is preferable to select the second position information, and to select the first position information when the surrounding vehicle is outside the detectable range of the second detection means.

  According to this, as described above, even if the fusion position information cannot be obtained, the distance from the surrounding vehicle in the position information of any one of the first and second detection means is determined by the determination means. Since the wobble determination of the surrounding vehicle can be performed based on the temporal variation of the vehicle and the temporal variation of the lateral position of the surrounding vehicle, the detection range of the surrounding vehicle is not narrowed.

  The above-described wobbling determination device preferably further includes a reliability calculation unit that obtains the reliability of the wobbling determination by the determination unit based on the selection result of the selection unit and the detection accuracy of the first and second detection units.

  As described above, since the detection accuracy of the first and second position information detected by the first and second detection means and the fusion position information are different, determination is made depending on which of these is selected by the selection means. The accuracy of the determination of the wobbling of surrounding vehicles by the means is different. Therefore, by determining the reliability of the wobbling determination by the determining unit based on the selection result of the selecting unit and the detection accuracy of the first and second detecting units, the reliability is also considered in addition to the wobbling determination by the determining unit. It is possible to provide appropriate driving assistance.

  ADVANTAGE OF THE INVENTION According to this invention, the precision of the wobble determination of a surrounding vehicle can be improved, without narrowing the detection range of a surrounding vehicle.

It is a figure which shows the driving assistance apparatus which concerns on this embodiment, and the wobble determination apparatus which concerns on embodiment of this invention. It is a figure which shows the detection range of the millimeter wave radar and stereo camera which are shown in FIG. It is a flowchart which shows the wobble determination process by the wobble determination apparatus which concerns on embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a diagram illustrating a driving support apparatus according to the present embodiment. A driving assistance apparatus 1 shown in FIG. 1 includes a vehicle sensor 10, a millimeter wave radar (first detection means, first calculation means) 20, and a stereo camera (second detection means, second calculation means) 30. And an electronic control unit (hereinafter referred to as an ECU: Electronic Control Unit) 40, various actuators 50, and a notification unit 60.

  The vehicle sensor 10 detects the speed, acceleration (deceleration), yaw rate, steering wheel steering angle, brake pedal depression amount, accelerator pedal depression amount, and the like of the host vehicle. The vehicle sensor 10 transmits each detected signal to the ECU 40.

  The millimeter wave radar 20 is a radar for detecting an object using millimeter wave radio waves. The millimeter wave radar 20 is attached to the front center of the host vehicle. The millimeter wave radar 20 transmits a millimeter wave band radio wave toward the front of the host vehicle, and receives a radio wave reflected on the surface of an object such as the front vehicle. Based on this signal, the millimeter wave radar 20 functions as a first calculation means, such as the presence or absence of a preceding vehicle, the distance and relative speed between the preceding vehicle and the host vehicle, and the lateral position of the preceding vehicle with respect to the host vehicle. Find location information. Then, the millimeter wave radar 20 sets the detected preceding vehicle as a radar target, sets the obtained position information as a radar target (radar target setting process), and transmits it to the ECU 40.

  The stereo camera 30 includes two CCD cameras, and the two CCD cameras are arranged at a predetermined interval in the horizontal direction. The stereo camera 30 is also attached to the front center of the host vehicle. The stereo camera 30 functions as a second computing means, and based on the left and right stereo image data captured by the two CCD cameras, the presence or absence of the preceding vehicle, the distance and relative speed between the preceding vehicle and the host vehicle, and Position information such as the lateral position of the preceding vehicle with respect to the host vehicle is obtained. Then, the stereo camera 30 sets the detected preceding vehicle as a stereo image target, sets the obtained position information as a stereo image target (stereo image target setting process), and transmits it to the ECU 40.

  The ECU 40 includes a CPU (Central Processing Unit) that performs calculations, a ROM (Read Only Memory) that stores programs for causing the CPU to execute each process, a RAM (Random Access Memory) that stores various data such as calculation results, and the like. It is configured. With such a configuration, the ECU 40 is configured with a wobbling determination ECU (light wobbling determination device) 70 and a driving support ECU 80. In this embodiment, an example in which the wobbling determination ECU 70 and the driving support ECU 80 are configured by one ECU 40 is shown, but the wobbling determination ECU 70 and the driving support ECU 80 may be configured by separate ECUs.

  The wobbling determination ECU 70 performs the wobbling determination of the forward vehicle based on the detection result by the millimeter wave radar 20, the detection result by the stereo camera 30, and the sensor fusion of these detection results. Further, the wobbling determination ECU 70 determines the reliability of the wobbling determination based on the detection accuracy of the millimeter wave radar 20 and the stereo camera 30.

  The driving support ECU 80 controls various actuators 50 such as a throttle actuator and a brake actuator based on various information detected by the vehicle sensor 10 and performs ACC (Adaptive Cruise Control) traveling control. Alternatively, the driving support ECU 80 controls the notification unit 60 such as an image display notification by a display or a voice notification by a speaker or a buzzer to guide a safe driving operation to the driver. The driving support ECU 80 controls, for example, various actuators 50 based on the wobbling determination result of the wobbling determination ECU 70 and the reliability thereof, and performs control to increase the inter-vehicle distance in ACC travel control, or cancels ACC travel control. Or Alternatively, the driving support ECU 80 controls the notification unit 60 to guide a safe driving operation to the driver.

  Next, a description will be given of the wobbling determination ECU (wobble determination device) 70 according to the embodiment of the present invention. The fluctuation determination ECU 70 includes a matching unit 73, a fusion calculation unit (fusion calculation unit) 74, a selection unit 75, a determination unit 76, and a reliability calculation unit 77.

  For example, the millimeter wave radar (first computing means) 20 obtains the distance between the host vehicle and the preceding vehicle based on the time from transmission to reception of millimeter waves. Further, the millimeter wave radar 20 obtains a relative speed with respect to the preceding vehicle using the Doppler effect. Also, the millimeter wave radar 20 detects the direction of the millimeter wave that has been reflected most strongly among the reflected millimeter waves, and obtains the angle formed by the traveling direction of the host vehicle and the direction of the preceding vehicle from that direction. The lateral position is obtained from the angle. The millimeter wave radar 20 sets these distance, relative speed, and lateral position as radar targets.

  In the detection by the millimeter wave radar 20, the accuracy of the distance and the relative speed is high, and the accuracy of the angle (that is, the lateral position) is low. Since the millimeter wave radar 20 calculates the distance based on the time until the transmitted millimeter wave is reflected and returned, the distance accuracy is high. Further, since the millimeter wave radar 20 calculates the relative speed using the Doppler effect, the accuracy of the relative speed is high. However, since it is not known where the millimeter wave is reflected most strongly in the width direction of the object to be detected, the position in the width direction (lateral position) varies, and the accuracy of the angle is lowered.

  For example, the stereo camera (second computing means) 30 extracts the preceding vehicle from the captured image by image recognition (edge extraction, pattern recognition processing, etc.). In addition, the stereo camera 30 obtains the distance between the host vehicle and the preceding vehicle by a triangulation method using the difference in the appearance of the object in the left and right stereo images. Further, the stereo camera 30 obtains the relative speed from the time change of the calculated distance. Further, the stereo camera 30 detects both ends of the detected object in the width direction, obtains an angle formed by the traveling direction of the own vehicle and the directions of the two ends, and obtains a lateral position from the angle. Then, the stereo camera 30 sets these distance, relative speed, and lateral position as a stereo image target.

  In the detection by the stereo camera 30, the accuracy of the distance and the relative speed is low, and the accuracy of the angle (that is, the lateral position) is high. Since both ends in the width direction of the detection target object can be detected with high accuracy from the left and right image data, the accuracy of the angle (that is, the lateral position) is increased. However, since image data from the left and right CCD cameras separated by, for example, about several tens of centimeters is used, the distance and relative speed accuracy are reduced because the distance is calculated with a very acute triangulation.

  The collation unit 73 collates at predetermined time intervals whether or not the previously selected target selected by the selection unit 75 described later and the current radar target are those in which the same preceding vehicle is detected. For example, the collation unit 73 determines the position (distance, lateral position) of the previous selected target and the position (distance, lateral position) of the current radar target based on the position (distance, lateral position) and relative speed of the previously selected target. ) Between the relative speed of the previously selected target and the relative speed of the current radar target is within the threshold. In this determination, it is determined that the current radar target is similar to the previous selected target when it is within all thresholds, and it is determined that there is no similarity when even one of the targets is not within the threshold. .

  Similarly, the collation unit 73 collates whether or not the previously selected target and the current stereo image target have detected the same preceding vehicle at regular time intervals. For example, based on the position (distance, horizontal position) and relative speed of the previously selected target, the collation unit 73 and the position (distance, horizontal position) of the previous selected target (distance, horizontal position) and the current stereo image target are selected. Position) is within the threshold, and whether the difference between the relative speed of the previously selected target and the current stereo image target is within the threshold. To do. In this determination, if the current stereo image target is similar to the previously selected target when all the thresholds are within the threshold, it is determined that there is no similarity if even one of the targets is not within the threshold. To do.

  Further, when there are a current radar target and a current stereo image target that are similar to the previously selected target, the collation unit 73 has the same current radar target and the current stereo image target. It is verified whether or not the preceding vehicle has been detected. For example, the matching unit 73 determines whether or not the difference between the current radar target position (distance, horizontal position) and the current stereo image target position (distance, horizontal position) is within a threshold, and this time It is determined whether or not the difference between the relative speed of the radar target and the relative speed of the current stereo image target is within a threshold value. In this determination, it is determined that the current radar target and the current stereo image target are similar if they are within all the thresholds, and if there is no similarity, it is determined that there is no similarity. To do.

  The fusion calculation unit 74 fuses the position information obtained by the millimeter wave radar 20 and the position information obtained by the stereo camera 30 when there is similarity in all the collations performed by the collation unit 73. Fusion position information (fusion position information) such as the presence or absence of the vehicle, the distance and relative speed between the preceding vehicle and the host vehicle, and the lateral position of the preceding vehicle with respect to the host vehicle is obtained. Then, the fusion calculation unit 74 sets the preceding vehicle detected by the millimeter wave radar 20 and the stereo camera 30 as the fusion target, and sets the obtained fusion position information as the fusion target (fusion target setting process).

For example, the fusion calculation unit 74 detects the distance detection accuracy ± Z _X1 and the lateral position detection accuracy ± Z _Y1 by the millimeter wave radar 20, and the distance detection accuracy ± Z _X2 and the lateral position detection accuracy ± Z _Y2 by the stereo camera 30. The distance X _{1 to the} surrounding vehicle and the lateral position Y _{1 of} the surrounding vehicle obtained by the millimeter wave radar 20, the distance X _{2 to the} surrounding vehicle and the lateral position Y ₂ to the surrounding vehicle obtained by the stereo camera 30. case, obtaining the distance X ₃ and lateral position Y ₃ around the vehicle with the nearby vehicle at the fusion position information by the following equation.
X ₃ = (Z _X2 × X ₁ + Z _X1 × X ₂ ) / (Z _X1 + Z _X2 )
_{Y 3 = (Z Y2 × Y} 1 + Z Y1 × Y 2) / (Z Y1 + Z Y2)

For example, the detection accuracy of the distance X ₁ by the millimeter wave radar 20 is ± Z _X1 = ± 10 cm, the detection accuracy of the lateral position Y ₁ is ± Z _Y1 = ± 100 cm, and the detection accuracy of the distance X ₂ by the stereo camera 30 is ± When Z _X2 = ± 50 cm and the detection accuracy of the lateral position Y ₂ is ± Z _Y2 = ± 10 cm, the distance X ₃ and the lateral position Y ₃ in the fusion position information are obtained as follows.
X ₃ = (5 × X ₁ + X ₂ ) / 6
Y ₃ = (Y ₁ + 10 × Y ₂ ) / 11

  In this way, the fusion calculation unit 74 obtains fusion position information in which the distance and relative speed between the preceding vehicle and the host vehicle and the lateral position of the preceding vehicle with respect to the host vehicle are both highly accurate.

  The selection unit 75 selects one of a radar target (first position information), a stereo image target (second position information), and a fusion target (fusion position information) based on the presence position of the preceding vehicle. One of the targets (position information) is selected.

  FIG. 2 shows detection ranges of the millimeter wave radar 20 and the stereo camera 30. In the detection by the millimeter wave radar 20, the detectable distance is relatively long, but the detectable lateral range is relatively narrow. On the other hand, in the detection by the stereo camera 30, the detectable lateral range is relatively wide, but the detectable distance is relatively short.

  Therefore, the selection unit 75 selects a radar target when the preceding vehicle exists in the region R1 exceeding the detection limit distance of the stereo camera 30, and selects the radar vehicle in the region R2 exceeding the detection limit width of the millimeter wave radar 20. If it exists, a stereo image target is selected. The selection unit 75 selects a fusion target when the preceding vehicle is present in the region R3 within the detection limit distance of the stereo camera 30 and within the detection limit width of the millimeter wave radar 20.

  Based on the position information (distance, lateral position) on the target selected by the selection unit 75, the determination unit 76 determines the degree of staggering for each of the distance to the preceding vehicle and the lateral position of the preceding vehicle. The degree of wobbling is, for example, the wobbling amplitude or wobbling period.

  The reliability calculation unit 77 is based on the detection accuracy of the sensor that has detected the target selected by the selection unit 75, that is, the detection accuracy of the wobbling degree determination by the determination unit 76 based on the detection accuracy of the millimeter wave radar 20 and the stereo camera 30. Ask for.

  For example, when the radar target is selected by the selection unit 75, the reliability calculation unit 77 increases the reliability of the determination of the degree of fluctuation of the distance from the preceding vehicle based on the detection accuracy of the millimeter wave radar 20. And the reliability of the determination of the degree of wobbling of the lateral position of the preceding vehicle is “low”. On the other hand, when the stereo image target is selected by the selection unit 75, the reliability calculation unit 77 sets the reliability of the determination of the degree of staggering of the distance from the preceding vehicle based on the detection accuracy of the stereo camera 30 to “low”. And the reliability of the determination of the degree of wobbling of the lateral position of the preceding vehicle is “high”. When the fusion target is selected by the selection unit 75, the reliability calculation unit 77 determines the degree of fluctuation of the distance from the preceding vehicle and the preceding based on the detection accuracy of the millimeter wave radar 20 and the stereo camera 30. The reliability of the determination of the wobbling degree for the lateral position of the vehicle is both “high + α”.

  Next, the operation of the wobble determination ECU 70 of this embodiment will be described. FIG. 3 is a flowchart showing the wobbling determination process by the wobbling determination ECU 70 of the present embodiment.

  Sensor fusion is performed by the millimeter wave radar 20, the stereo camera 30, the matching unit 73, and the fusion calculation unit 74.

  Specifically, the millimeter wave radar (first calculation means) 20 obtains position information such as the presence or absence of a preceding vehicle, the distance and relative speed between the preceding vehicle and the host vehicle, and the lateral position of the preceding vehicle with respect to the host vehicle. It is obtained and set as a radar target (radar target setting process) (S01). Further, the stereo camera (second computing means) 30 obtains position information such as the presence or absence of the preceding vehicle, the distance and relative speed between the preceding vehicle and the host vehicle, and the lateral position of the preceding vehicle with respect to the host vehicle, and the stereo image A target is set (stereo image target setting process) (S02).

  Next, the collation unit 73 detects whether or not the previous selected target and the current radar target have detected the same preceding vehicle, and the previous selected target and the current stereo image target have the same preceding vehicle. Whether the vehicle has been detected and whether the current radar target and the current stereo image target have detected the same preceding vehicle are collated (S03). If there is similarity in all the collations, the fusion calculation unit 74 fuses the position information obtained by the millimeter wave radar 20 and the position information obtained by the stereo camera 30 to determine whether there is a preceding vehicle, Fusion position information such as the distance and relative speed between the preceding vehicle and the host vehicle and the lateral position of the preceding vehicle with respect to the host vehicle is obtained and set as a fusion target (fusion target setting process) (S04).

  Next, based on the position where the preceding vehicle is present, the selection unit 75 selects a radar target (first position information), a stereo image target (second position information), and a fusion target (fusion position information). One of the targets (position information) is selected. Specifically, the selection unit 75 determines whether or not the preceding vehicle is detected only by the millimeter wave radar 20, that is, whether or not the position information of the preceding vehicle is obtained only by the millimeter wave radar 20 (S05). ), When the position information of the preceding vehicle is obtained only by the millimeter wave radar 20, it is determined that the preceding vehicle exists in the region R1 exceeding the detection limit distance of the stereo camera 30, and the radar target (first position information) Select. Then, based on the position information (distance, lateral position) in the radar target, the determination unit 76 determines the degree of staggering for each of the distance to the preceding vehicle and the lateral position of the preceding vehicle (S06). Further, the reliability calculation unit 77 obtains the reliability of the determination of the fluctuation degree by the determination unit 76 based on the detection accuracy of the millimeter wave radar 20 (millimeter wave radar single detection fluctuation determination) (S07).

  On the other hand, when the position information of the preceding vehicle is not obtained only by the millimeter wave radar 20 in step 05, whether or not the preceding vehicle is detected only by the stereo camera 30 by the selection unit 75, that is, the preceding vehicle's position information. It is determined whether or not the position information is obtained only by the stereo camera 30 (S08). When the position information of the preceding vehicle is obtained only by the stereo camera 30, the preceding vehicle sets the detection limit width of the millimeter wave radar 20. A stereo image target (second position information) is selected by determining that it exists in the region R2 beyond. Then, based on the position information (distance, lateral position) in the stereo image target, the determination unit 76 determines the degree of staggering for each of the distance to the preceding vehicle and the lateral position of the preceding vehicle (S09). Further, the reliability calculation unit 77 obtains the reliability of the determination of the degree of wobbling by the determination unit 76 based on the detection accuracy of the stereo camera 30 (stereo camera single detection wobbling determination) (S10).

  On the other hand, when the position information of the preceding vehicle is not obtained only by the stereo camera 30 in step 08, that is, when the position information of the preceding vehicle is obtained by the millimeter wave radar 20 and the stereo camera 30, the selection unit 75 It is determined that the preceding vehicle exists in the region R3 within the detection limit distance of the stereo camera 30 and within the detection limit width of the millimeter wave radar 20, and the fusion target (fusion position information) is selected. Then, based on the fusion position information (distance, lateral position) in the fusion target, the determination unit 76 determines the degree of staggering for each of the distance to the preceding vehicle and the lateral position of the preceding vehicle (S11). Further, the reliability calculation unit 77 obtains the reliability of the determination of the fluctuation degree by the determination unit 76 based on the detection accuracy of the millimeter wave radar 20 and the stereo camera 30 (millimeter wave radar and stereo camera detection fluctuation determination) (S12). ).

  Note that, as described above, each process shown in FIG. 3 is repeated at regular time intervals, so that it is possible to perform the wobble determination from the second and subsequent flows.

  Thereafter, as described above, driving assistance by the driving assistance ECU 80 is performed based on the determination result of the wobbling and the reliability thereof.

  As described above, according to the fluctuation determination ECU 70 of the present embodiment, the fusion calculation unit 74 fuses the position information detected by the millimeter wave radar 20 and the position information detected by the stereo camera 30, thereby detecting accuracy. It is possible to obtain fusion position information having a distance from a preceding vehicle having a high speed and a lateral position of the preceding vehicle having a high detection accuracy. Therefore, the determination unit 76 performs the wobble determination of the preceding vehicle by performing the wobble determination of the preceding vehicle based on the temporal variation of the distance to the preceding vehicle and the temporal variation of the lateral position of the preceding vehicle in the fusion position information. Accuracy can be increased.

  Further, according to the fluctuation determination ECU 70 of the present embodiment, when the position of the preceding vehicle is within the undetectable region of one of the millimeter wave radar 20 and the stereo camera 30, that is, the fusion position information. Can not be obtained, the selection unit 75 can select the position information of the other sensor. Therefore, even when the fusion position information cannot be obtained, the determination unit 76 causes the temporal variation of the distance from the preceding vehicle and the preceding vehicle in the position information of any one of the millimeter wave radar 20 and the stereo camera 30. The wobble determination of the preceding vehicle can be performed based on the temporal variation of the lateral position of the vehicle. Therefore, according to the wobbling determination ECU 70 of the present embodiment, the detection range of the preceding vehicle is not narrowed.

  As described above, since the detection accuracy of the first and second position information detected by the millimeter wave radar 20 and the stereo camera 30 and the fusion position information are different, determination is made depending on which of these is selected by the selection unit 75. The accuracy of the wobbling determination of surrounding vehicles by the unit 76 is different. Therefore, by determining the reliability of the wobbling determination by the determining unit 76 based on the selection result of the selecting unit 75 and the detection accuracy of the millimeter wave radar 20 and the stereo camera 30, the reliability in addition to the wobbling determination by the determining unit 76 is obtained. Therefore, it is possible to perform appropriate driving support that also takes into account.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, in the present embodiment, the millimeter wave radar and the stereo camera are exemplified as the combination of the wobbling detection sensors of the preceding vehicle. However, various combinations of sensors such as a radio wave sensor other than the millimeter wave band, a laser radar, and a monocular image camera are available. Applicable. For example, a laser radar has a shorter wavelength than a millimeter wave radar, so the lateral position detection accuracy is relatively high and the lateral detection range is relatively wide, so the combination of millimeter wave radar and laser radar Even if it exists, the same advantage as this embodiment can be acquired.

  Further, in the present embodiment, the determination of the wobbling of the preceding vehicle is exemplified, but the wobbling determination of the surrounding vehicle such as the following vehicle can be performed according to the mounting positions of various sensors.

  In the present embodiment, the wobble determination is performed using short-term fluctuations in the distance and the lateral position. However, the wobble determination may be performed using various physical quantities that correlate with a driver's consciousness decrease.

  DESCRIPTION OF SYMBOLS 1 ... Driving assistance device, 10 ... Vehicle sensor, 20 ... Millimeter wave radar (1st detection means, 1st calculation means), 30 ... Stereo camera (2nd detection means, 2nd calculation means), 40 ... ECU, 50 ... various actuators, 60 ... notifying unit, 70 ... stagger determination ECU (stagger determination device), 73 ... collation unit, 74 ... fusion calculation unit (fusion calculation unit), 75 ... selection unit (selection unit), 76 ... Determination unit (determination unit), 77... Reliability calculation unit (reliability calculation unit), 80.

Claims (6)

First calculation means for obtaining a distance to the surrounding vehicle and a lateral position of the surrounding vehicle as first position information of the surrounding vehicle detected by the first detection means;
A second distance for obtaining the distance to the surrounding vehicle and the lateral position of the surrounding vehicle as the second position information of the surrounding vehicle detected by the second detecting means using a detection principle different from that of the first detecting means; Computing means;
A fusion calculation means for obtaining a distance to the surrounding vehicle and a lateral position of the surrounding vehicle as fused position information of the surrounding vehicle by fusing the first and second position information;
Selection means for selecting any one of the first and second position information and the fusion position information based on the position of the surrounding vehicle;
A determination unit configured to perform a wobble determination of the surrounding vehicle based on a distance from the surrounding vehicle in the position information selected by the selection unit and a temporal variation of each lateral position of the surrounding vehicle;
A wobble determination device. The fusion calculation means includes distance detection accuracy ± Z _X1 and lateral position detection accuracy ± Z _Y1 by the first detection means, distance detection accuracy ± Z _X2 and lateral position accuracy by the second detection means. Based on the detection accuracy ± Z _Y2 , the distance X ₁ to the surrounding vehicle in the first position information, the lateral position Y _{1 of} the surrounding vehicle, and the distance X ₂ to the surrounding vehicle in the second position information. and in the case of lateral position Y ₂ of the peripheral vehicle, determine the lateral position Y ₃ of the distance X ₃ and the peripheral vehicle and the peripheral vehicle in the fusion position information by the formula,
X ₃ = (Z _X2 × X ₁ + Z _X1 × X ₂ ) / (Z _X1 + Z _X2 )
_{Y 3 = (Z Y2 × Y} 1 + Z Y1 × Y 2) / (Z Y1 + Z Y2)
The wobble determination device according to claim 1. The first detecting means is a radar;
The second detection means is a camera;
The wobbling determination device according to claim 1 or 2. The first detection means is a millimeter wave radar;
The second detection means is a laser radar;
The wobbling determination device according to claim 1 or 2. The selection means selects the fusion position information when the surrounding vehicle is within the detectable range of the first and second detection means, and the surrounding vehicle can be detected by the first detection means. Selecting the second position information when it is outside the range, and selecting the first position information when the surrounding vehicle is outside the detectable range of the second detection means;
The wobble determination device according to claim 1. Further comprising a reliability calculation means for determining the reliability of the wobbling determination by the determination means based on the selection results of the selection means and the detection accuracy of the first and second detection means.
The wobbling determination device according to claim 1 or 2.

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