JP2009014479A - Object detection device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an object detection device for a vehicle capable of detecting a relative position and a relative speed of a front vehicle with high accuracy. <P>SOLUTION: A representative point calculation means calculates an end point 87a to be calculated as an intersection point of two lines, when the two lines are recognized based on the arrangement of the reflection points of a font vehicle 87, and calculates the center-of-gravity point 77a of one line as a representative point, when the one line is recognized based on the arrangement of the reflection points of a front vehicle 77. A representative point correction means is so configured as to correct a representative point from an end point to a center-of-gravity point 86a, when a relative distance of a front vehicle 86 is not shorter than a predetermined distance d. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle object detection device. In particular, pulsed transmission waves are intermittently emitted using a laser radar, reflected waves from an object are detected, the distance to the object is calculated based on the time from emission to detection, and the width, position, and movement of the object are calculated. The present invention relates to a device for avoiding contact with an obstacle by measuring the above and performing an alarm and vehicle control.

  Various vehicle object detection devices have been developed. Scanning radar is equipped with electromagnetic wave radar, laser radar, etc. on the vehicle, irradiates a predetermined angle range in front of the vehicle with a scanning mechanism, such as light waves and millimeter waves, and detects reflected waves from the object, It recognizes an object in front of the vehicle. This type of device is applied, for example, to a device that controls the vehicle speed so as to maintain a predetermined inter-vehicle distance from the preceding vehicle. It also recognizes obstacles in front of the vehicle, determines the possibility of contact with obstacles based on the relative distance and relative speed between the obstacle and the vehicle, prompts the driver for warnings and avoidance operations, and automatically brakes. It is applied to the device which operates.

  In the above-described technique, it is necessary to estimate the relative speed between the preceding vehicle and the host vehicle with high accuracy in order to determine a collision or the like. The relative speed is obtained by performing the same object determination (tracking) on the preceding vehicle detected in time series by the laser radar and changing the relative position with the own vehicle per unit time. In order to obtain the relative speed with high accuracy, it is necessary to correctly track the preceding vehicle detected in time series by the laser radar. In order to accurately track the vehicle ahead, it is necessary to correctly detect the position coordinates of the vehicle ahead. Since an object such as a vehicle has a certain size, it is necessary to continuously detect the position coordinates of a specific portion of the vehicle. Below, this specific part of the vehicle is referred to as a representative point.

  FIG. 7 is an explanatory diagram of an object detection method according to the prior art. In this object detection method, the center-of-gravity point 64 on the front surface of the front vehicle 60 is recognized as a representative point of the front vehicle 60. In this case, if the entire front surface of the front vehicle 60 enters the radar scanning range 13 and the reflection point 62 is recognized for the entire front surface, the center point of the front surface of the hand can be calculated as the barycentric point 64. However, when the vehicle 60 existing diagonally forward of the host vehicle 5 approaches the host vehicle 5, a part of the front surface of the front vehicle 60 is out of the radar scanning range 13. In this case, if the barycentric point 64 is calculated from the remaining reflection points on the front of the hand existing in the radar scanning range 13, the position of the barycentric point 64 is shifted in the width direction. As a result, although the forward vehicle 60 is traveling straight, it is mistaken that the course of the vehicle is turning toward the host vehicle 5.

As a method for performing interpolation calculation of the position of the portion outside the scanning range when a part of the preceding vehicle deviates from the radar scanning range, an object position detection method described in Patent Document 1 can be cited. This object position detection method measures the distance and direction to the object existing within the detection angle and the horizontal width of the object, and measures the motion vector of the horizontal position of the object from the distance and direction to the object being measured. If the width of the object is memorized and it is determined that a part of the object being measured is out of the detection angle, the memorized width of the object and the object measured within the detection angle are stored. Based on the lateral position motion vector, the position of the portion outside the detection angle is interpolated. Thus, the position and width of the object, the range where the object exists, and the locus of the center position of the object can be correctly obtained.
JP 2002-122669 A

  However, in the technique described in Patent Document 1, when the preceding vehicle approaches the host vehicle and falls outside the laser scanning range, the lateral width calculated when the preceding vehicle exists far away is used. The position of the portion outside the scanning range is interpolated. In particular, when the preceding vehicle is an oncoming vehicle, the lateral width calculated at the front portion where there is no reflector is used. Due to the error in the width dimension, the interpolation accuracy of the vehicle ahead decreases and the calculation accuracy of the center of gravity decreases. Accordingly, there is a problem that the relative position and the relative speed cannot be obtained with high accuracy.

  Accordingly, an object of the present invention is to provide a vehicle object detection device capable of accurately obtaining the relative position and relative speed of an object to be detected.

  In order to solve the above-mentioned problem, the invention according to claim 1 transmits an electromagnetic wave to a predetermined range around the host vehicle (for example, the host vehicle 5 in the embodiment), and an object (e.g., an object existing around the host vehicle). Transmission / reception means (for example, the radar 12 in the embodiment) that receives reflected waves from the forward vehicles 70 and 80 in the embodiment, and reflection point calculation means (for example, the position of the reflection point of the electromagnetic wave on the object) Reflection point calculation means 14) in the embodiment, representative point calculation means (for example, representative point calculation means 18 in the embodiment) for calculating the position of a representative point representing the position of the object based on the reflection point, and the representative Relative relationship calculating means for calculating a relative relationship consisting of a relative position and a relative distance between the host vehicle and the object based on a point (for example, relative relationship calculation in the embodiment) Means 20) and relative speed calculation means (for example, relative speed calculation means 21 in the embodiment) for calculating a relative speed between the host vehicle and the object based on the relative position. (For example, the vehicle object detection device 10 in the embodiment), and line segment recognition means for recognizing a line segment constituting the contour of the object based on the arrangement of the reflection points (for example, line segment recognition in the embodiment) Means 16) and representative point correcting means (for example, representative point correcting means 26 in the embodiment) for correcting the position of the representative point based on the relative distance, and the representative point calculating means includes the line segment. When two line segments are recognized by the recognition means, the end point of the object (for example, the end point 84 in the embodiment) calculated as the intersection of the line segments is recognized when one line segment is recognized. A centroid point of the line segment (for example, the centroid point 74 in the embodiment) is calculated as the representative point, and the representative point correction unit is configured such that the relative distance is equal to or greater than a predetermined distance (for example, the predetermined distance d in the embodiment). Further, the representative point is corrected from the end point to the barycentric point.

  According to a second aspect of the present invention, there is provided width calculation means (for example, width calculation means 22 in the embodiment) for calculating the width of the object in the width direction of the host vehicle based on the reflection point, and the time calculation in the time series. Deviation judging means (for example, deviation judging means 24 in the embodiment) that compares the width of the object and judges that a part of the object has deviated out of the predetermined range when the width of the object has decreased. And the representative point correcting means is the direction in which the relative speed is toward the host vehicle, and the deviation determining means determines that a part of the object has deviated from the predetermined range. The representative point is corrected from the barycentric point to the end point.

  According to a third aspect of the present invention, the relative speed calculating means is configured to change the representative point from one of the center of gravity point and the end point to the other from the previous calculation of the relative position to the current calculation of the relative position. In this case, the relative speed in the width direction of the host vehicle is not calculated.

  According to a fourth aspect of the present invention, there is provided width calculation means for calculating the width of the object in the width direction of the host vehicle based on the reflection point, and the relative speed calculation means is determined from the previous calculation of the relative position. When the representative point is changed from one of the centroid point and the end point to the other during the calculation of the relative position this time, the relative position previously calculated based on the width of the object calculated by the width calculation unit The relative speed in the width direction of the host vehicle is calculated while correcting the position.

According to the first aspect of the present invention, when the object is present obliquely forward of the transmission / reception means, two line segments are recognized along the front side of the hand and the side surface on the own vehicle side. An end point is calculated as a representative point. Therefore, even when the vicinity of the end point on the opposite side of the object deviates outside the predetermined range around the host vehicle, there is no need to reset the representative point, and a part of the object deviating outside the predetermined range is interpolated. There is no need to recalculate. Therefore, the relative position and relative speed of the object can be calculated with high accuracy.
In addition, since the representative point is corrected from the end point to the center of gravity when the relative distance to the object is greater than or equal to the predetermined distance, averaging is performed even when the position accuracy is low because the object is far away and the number of reflection points is small. The center of gravity obtained by processing can be used as the representative point, and the position accuracy of the representative point can be ensured. Therefore, the relative position and relative speed of the object can be calculated with high accuracy.

  According to the invention of claim 2, even when a part of an object deviates from the predetermined range to the outside of the range, the tracking of the forward vehicle can be continued by resetting the representative point from the center of gravity to the end point. it can.

Note that when the representative point is changed from one of the center of gravity and the end point to the other from the time of the previous calculation of the relative position to the time of the calculation of the current relative position, the relative speed in the width direction is calculated unlike the actual situation. It will be.
On the other hand, according to the invention according to claim 3, since the relative speed in the width direction of the host vehicle is not calculated in that case, the reliability of the calculated relative position and relative speed can be improved. .

When the representative point is changed from one of the center of gravity point and the end point to the other, the position of the representative point is shifted by about half of the width of the object.
According to the fourth aspect of the invention, the relative position in the width direction of the host vehicle is calculated while correcting the relative position calculated last time based on the width of the object, so that the relative position and the relative speed of the object are accurately calculated. can do.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Vehicle object detection device)
FIG. 1 is a block diagram of the vehicle object detection device according to the present embodiment. The vehicle object detection device 10 according to the present embodiment is mounted on a vehicle 5, and is a representative of a preceding vehicle from a radar 12 that transmits and receives electromagnetic waves, an electromagnetic wave reflection point calculation means 14, and a plurality of reflection points. Representative point calculating means 18 for calculating points, relative relationship calculating means 20 for calculating the relative relationship between the host vehicle 5 and the preceding vehicle based on the representative points, and relative speed calculating means 21 for calculating the relative speed. . The reflection point calculation means 14, the representative point calculation means 18, the relative relationship calculation means 20, the relative speed calculation means 21, etc. other than the radar 12 are constructed in the computer 8 mounted on the vehicle 5.

  A radar 12 such as a laser radar or a millimeter wave radar is mounted on the front of the vehicle 5. The radar 12 includes a transmission unit that transmits electromagnetic waves and a reception unit that receives reflected waves. The transmission unit can scan the predetermined angle range 13 while transmitting electromagnetic waves forward. The receiving unit receives the reflected wave transmitted from the transmitting unit and reflected by the vehicle ahead.

  Further, there is provided a reflection point calculation means 14 for calculating a point at which the electromagnetic wave transmitted by the radar 12 is reflected by the vehicle ahead. In general, the direction in which the reflection point exists can be detected from the incident direction of the reflected wave to the host vehicle. Since the propagation speed of the electromagnetic wave is constant, the distance to the reflection point can be calculated from the time required for transmission / reception. Then, based on the direction and distance of the reflection point with respect to the host vehicle, the relative position (coordinates) of the reflection point with respect to the host vehicle can be calculated.

Further, representative point calculation means 18 for calculating the position of the representative point representing the position of the preceding vehicle is provided. The representative point calculation means 18 calculates a representative point by the following method in principle.
FIG. 2 is an explanatory diagram of a principle representative point calculation method. When the front vehicle 70 is present in front of the host vehicle 5, the electromagnetic waves emitted from the host vehicle 5 are reflected only on the front surface of the front vehicle 70. Therefore, a plurality of reflection points 72 are detected only on the front surface of the front vehicle 70. In this case, the barycentric points 74 of the plurality of reflection points 72 are calculated as representative points of the forward vehicle 70. When the preceding vehicle is a preceding vehicle that travels in the same direction as the host vehicle, the front side of the hand is the rear side. When the preceding vehicle is an oncoming vehicle that travels in the opposite direction to the host vehicle, the front side of the hand Is the front.

On the other hand, when the front vehicle 80 exists diagonally forward of the host vehicle 5, the electromagnetic waves emitted from the host vehicle 5 are reflected on the side surface of the host vehicle 5 in addition to the front surface of the front vehicle 80. Therefore, a plurality of reflection points 82 are detected on the front surface of the hand, and a plurality of reflection points 83 are also detected on the side surface. In this case, a line segment constituting the contour of the front surface of the hand is obtained from the plurality of reflection points 82, and a line segment constituting the outline of the side surface is obtained from the plurality of reflection points 83. Then, an intersection point between the contour line on the front side of the hand and the contour line on the side surface (that is, the corner end point on the own vehicle side of the forward vehicle) is calculated as a representative point of the forward vehicle.
The representative point calculating means 18 records the calculated representative point type (centroid point or end point) in the memory 28.

  In addition, in order to obtain | require the outline of a hand front, and the outline of a side, as shown in FIG. 1, the line segment recognition means 16 is provided. The line segment recognition means 16 is for recognizing a line segment constituting the contour of the preceding vehicle based on the arrangement of the reflection points. For calculation of each contour line, a least square method or the like can be used.

  On the other hand, a relative relationship calculating means 20 is provided for calculating a relative relationship consisting of a relative position and a relative distance between the host vehicle 5 and the preceding vehicle. The representative point calculation means 18 described above calculates the relative coordinates of the representative point of the preceding vehicle with respect to the host vehicle. The relative relationship calculation means 20 calculates a relative position and a relative distance between the host vehicle 5 and the preceding vehicle based on the relative coordinates. The calculated relative position is recorded in the memory 28 together with time information.

  Further, a relative speed calculation means 21 for calculating the relative speed between the host vehicle and the preceding vehicle is provided. The relative speed calculation unit 21 receives the current relative position from the relative relationship calculation unit 20 and reads the previous relative position recorded in the memory 28. And the relative speed of the own vehicle 5 and a preceding vehicle is calculated by calculating | requiring the difference of the relative position per unit time. The relative speed is calculated for each of two horizontal directions (the front-rear direction and the width direction of the host vehicle).

(Representative point correction means)
The vehicle object detection device 10 according to the present embodiment includes a representative point correction unit 26 that corrects the representative point calculated by the representative point calculation unit 18 based on the relative distance calculated by the relative relationship calculation unit 20. Yes.
FIG. 3 is an explanatory diagram of a representative point correction method. Since the front vehicle 87 existing diagonally forward of the host vehicle 5 has a plurality of reflection points detected on the front and side surfaces of the hand, the representative point calculation means 18 sets the representative point as the end point 87a. For the forward vehicle 86 existing obliquely forward of the host vehicle 5, the representative point is similarly set as the end point. On the other hand, the representative point correction means performs a process of correcting the representative point from the end point to the center of gravity 86a on the front surface of the forward vehicle 86 in which the relative distance between the forward vehicle 86 and the host vehicle 5 is equal to or greater than the predetermined distance d. .

  Returning to FIG. 1, width calculation means 22 for calculating the width of the preceding vehicle in the width direction of the host vehicle is provided. The width calculation unit 22 extracts a reflection point group (in front of the hand) that is substantially parallel to the width direction of the host vehicle from the plurality of reflection points of the preceding vehicle detected by the reflection point calculation unit 14. And the distance between the reflective points located in the both ends is calculated as the width of the preceding vehicle. As shown in FIG. 2, even when a part of the front surface of the front vehicle 90 deviates outside the radar scanning range 13, the distance between the reflection points at both ends of the remaining reflection points on the front surface of the front vehicle 90 is determined. The width should be The calculated width of the preceding vehicle is recorded in the memory 28 together with the time information.

  Returning to FIG. 1, departure determination means 24 is provided for determining that a part of the preceding vehicle has deviated outside the scanning range of the radar. In FIG. 3, the front vehicle 95 has the entire front face inside the radar scanning range 13, so that the reflection point is detected from the entire front face. On the other hand, since a part of the front surface of the front vehicle 96 deviates outside the radar scanning range 13, the reflection point is detected only from the remaining portion of the front surface of the hand. Therefore, when the forward vehicle 95 moves to the position of the forward vehicle 96, the distance between the reflection points at both ends is reduced, and the width of the forward vehicle calculated by the width calculation means 22 is reduced. Therefore, the departure determination means 24 shown in FIG. 1 receives the width of the preceding vehicle calculated this time from the width calculation means 22 and reads the width of the preceding vehicle calculated last time from the memory 28. Then, when the width of the preceding vehicle calculated this time has decreased from the previous time, it is determined that a part of the preceding vehicle has deviated out of the radar scanning range.

  When the center of gravity is calculated from the remaining reflection points on the front of the hand when a part of the front of the hand deviates outside the radar scanning range 13 as in the forward vehicle 96 shown in FIG. The position of the barycentric point varies depending on the amount of deviation from 13. When the position of the center of gravity is shifted in the width direction, the relative speed in the width direction is calculated. As a result, it is mistaken that the vehicle ahead is skewed even though the vehicle ahead is traveling straight.

  Therefore, the representative point correcting means 26 shown in FIG. 1 performs processing for correcting the representative point from the center of gravity point to the end point when a part of the preceding vehicle approaching the host vehicle deviates from the radar scanning range. That is, when the relative speed calculated by the relative speed calculating means 21 is in the direction toward the host vehicle and the departure determining means 24 determines that a part of the preceding vehicle has deviated outside the radar scanning range, the preceding vehicle The representative point is corrected from the center of gravity to the end point. Specifically, the representative point of the forward vehicle 95 shown in FIG. 3 is the center of gravity point 95a, but when this moves to the position of the forward vehicle 96, the representative point is corrected to the end point 96a. As described above, even when a part of the preceding vehicle deviates from the radar scanning range to the outside, the tracking of the preceding vehicle can be continued by resetting the representative point from the center of gravity to the end point.

  In addition, not only when the forward vehicle 95 moves to the position of the forward vehicle 96 and deviates outside the radar scanning range, but also when the forward vehicle 86 moves over the predetermined distance d to the position of the forward vehicle 87. The point is changed from the center of gravity to the end point. In this way, when the representative point is changed from one of the center of gravity point and the end point to the other, the relative speed in the width direction is calculated, and the vehicle is skewed even though the preceding vehicle is traveling straight ahead. It will be mistaken for.

  Therefore, the relative speed calculation means 21 shown in FIG. 1 does not calculate the relative speed in the width direction when the representative point is changed from one of the center of gravity and the end point to the other. Specifically, the relative speed calculation means 21 receives the current representative point type (centroid or end point) from the representative point calculation means and reads the previous representative point type from the memory 28. Then, when the type of the representative point this time is different from the previous time, the relative speed in the width direction is not calculated. Even in this case, the relative speed in the longitudinal direction of the host vehicle is calculated. Thereby, the reliability of the calculated relative position and relative speed can be improved.

  When the representative point is changed, the relative speed in the width direction may be corrected. When the representative point is changed from one of the center of gravity point and the end point to the other, the position of the representative point is shifted by about half of the width of the preceding vehicle. Therefore, it is desirable to calculate the relative speed while shifting the relative position of the preceding vehicle ahead by about half of the width of the preceding vehicle. Thereby, the relative position and relative speed of the vehicle ahead can be calculated with high accuracy.

  The vehicle object detection device 10 according to the present embodiment is connected to the inter-vehicle distance control means 32 and the collision avoidance means 34. The inter-vehicle distance control means 32 controls the vehicle speed of the host vehicle so as to maintain a predetermined inter-vehicle distance from the preceding vehicle. Specifically, the upper limit of the accelerator opening of the host vehicle is adjusted based on the relative relationship and the relative speed calculated as described above. One collision avoidance unit 34 determines the possibility of contact with the preceding vehicle based on the relative distance, the relative speed, and the like calculated as described above. Then, the driver is prompted to perform an alarm or avoidance operation, or the brake is automatically activated.

(Vehicle object detection method)
Next, the vehicle object detection method according to the present embodiment will be described.
FIG. 4 is a flowchart of the vehicle object detection method according to the present embodiment. First, in S10, the radar 12 transmits an electromagnetic wave to a predetermined range around the host vehicle and receives a reflected wave from a preceding vehicle. Next, in S12, the reflection point calculation means 14 calculates the position of the reflection point of the electromagnetic wave in the vehicle ahead. That is, as shown in FIG. 2, in the case of a forward vehicle 70 existing in front of the host vehicle 5, the position of the reflection point 72 on the front side of the hand is calculated. On the other hand, in the case of the vehicle 80 existing obliquely forward of the host vehicle 5, the position of the side reflection point 83 is calculated in addition to the reflection point 82 on the front surface of the hand.

Next, in S30, the representative point calculation means 18 calculates the position of the representative point representing the position of the preceding vehicle.
FIG. 5 is a flowchart of a representative point calculation subroutine. First, in S32, the line segment recognition means 16 recognizes the line segment that forms the contour of the preceding vehicle from the array of reflection points. Next, in S34, the representative point calculation means 18 determines whether there is one recognized line segment. If the determination is Yes (one line segment), the process proceeds to S36, and the representative point is set as the barycentric point. On the other hand, if the determination is No (two line segments), the process proceeds to S38, and the representative point is set as an end point. In other words, in the case of the forward vehicle 70 shown in FIG. 2, only one line segment is recognized on the front surface of the hand, so the representative point is set to the center of gravity point 74. On the other hand, in the case of the forward vehicle 80, since two line segments are recognized on the front and side surfaces of the hand, the representative point is set to the end point 84 that is the intersection of the two.

  Returning to FIG. 4, in S <b> 14, the relative relationship calculation means 20 calculates a relative relationship including the relative position and the relative distance between the host vehicle and the preceding vehicle. Next, in S16, the width calculation means 22 calculates the width of the preceding vehicle in the width direction of the host vehicle.

  Next, when the relative distance of the preceding vehicle is greater than or equal to the predetermined distance d, a process of correcting the representative point from the end point to the center of gravity is performed. Specifically, first, in S18, it is determined whether the representative point is a barycentric point. If the determination is No (representative point is an end point), the process proceeds to S20, and it is determined whether the relative distance between the host vehicle and the preceding vehicle is a predetermined distance d or more. If the determination is Yes (relative distance is d or more), the representative point correction unit 26 corrects the representative point from the end point to the center of gravity. If the determination in S18 is Yes (the representative point is the center of gravity), and the determination in S20 is No (relative distance is less than d), the representative point is not corrected.

  Next, when the relative speed of the preceding vehicle is in the direction toward the host vehicle and the preceding vehicle deviates outside the radar scanning range, processing for correcting the representative point from the center of gravity point to the end point is performed. Specifically, first, in S24, it is determined whether or not the width data of the preceding vehicle detected last time is recorded in the memory 28. If the determination is No (initial detection), the process proceeds to S26, and the relative relationship with the preceding vehicle calculated in S14 and the width of the preceding vehicle calculated in S16 are recorded in the memory 28. If the determination in S24 is Yes (second and subsequent detections), the process proceeds to S40, and the departure determination unit 24 performs departure determination.

  FIG. 6 is a flowchart of the departure determination subroutine. First, in S42, the width of the preceding vehicle detected last time is read from the memory 28. Next, in S44, the width of the preceding vehicle detected last time is compared with the width detected in S16 this time to determine whether the width of the preceding vehicle has decreased. When the determination is No, the representative point is not corrected. If the determination is Yes, since the relative speed of the preceding vehicle is in the direction toward the host vehicle and the preceding vehicle has deviated outside the radar scanning range, the representative point is corrected from the center of gravity to the end point. If the representative point is already set as an end point in S30, the representative point need not be corrected.

  Returning to FIG. 4, in S28, the relative speed calculation means 21 calculates the relative speed between the host vehicle and the preceding vehicle. Specifically, first, the identity determination (tracking process) between the preceding vehicle detected last time and the preceding vehicle detected this time is performed. When it is determined that they are the same, the relative speed is calculated using the relative position with the preceding vehicle calculated last time and the relative position calculated this time in S14. If the representative point is changed from one of the center of gravity and the end point to the other from the previous calculation to the current calculation, the relative speed in the width direction is not calculated as described above. The relative speed may be calculated while shifting the relative position of the preceding vehicle calculated last time by about half the width of the preceding vehicle.

As described above in detail, the vehicle object detection device according to the present embodiment is calculated as the intersection of line segments when two line segments are recognized based on the arrangement of the reflection points of the preceding vehicle. If one line segment is recognized as the end point of the preceding vehicle, the center point of the line segment is calculated as a representative point. If the relative distance of the front vehicle is greater than or equal to a predetermined distance, the representative point is calculated from the end point. It was set as the structure corrected to a point.
According to this configuration, when the forward vehicle is present obliquely in front of the host vehicle, two line segments along the front side of the hand and the side surface on the host vehicle side are recognized. Are calculated as representative points. Therefore, even if the vicinity of the end point on the opposite side of the preceding vehicle deviates outside the radar scanning range, there is no need to reset the representative point, and a part of the preceding vehicle that deviates outside the radar scanning range is interpolated to represent the representative point. There is no need to recalculate. Therefore, the relative position and relative speed of the preceding vehicle can be calculated with high accuracy.
In addition, since the representative point is corrected from the end point to the center of gravity when the relative distance of the front vehicle is equal to or greater than the predetermined distance, even if the front vehicle is far away, the number of reflection points is small and the position accuracy is low. It becomes possible to use the center of gravity obtained by the conversion processing as a representative point, and to ensure the position accuracy of the representative point. Therefore, the relative position and relative speed of the preceding vehicle can be calculated with high accuracy.

It is a block diagram of the object detection device for vehicles concerning an embodiment. It is explanatory drawing of a representative point calculation method. It is explanatory drawing of a representative point correction method. It is a flowchart of the object detection method for vehicles concerning an embodiment. It is a flowchart of a representative point calculation subroutine. It is a flowchart of a departure judgment subroutine. It is explanatory drawing of the object detection method which concerns on a prior art.

Explanation of symbols

  d ... Predetermined distance 5 ... Own vehicle 10 ... Vehicle object detection device 12 ... Radar (transmission / reception means) 13 ... Radar scanning range (predetermined range) 14 ... Reflection point calculation means 16 ... Line segment recognition means 18 ... Representative point calculation means 20 ... Relative relation calculating means 21 ... Relative speed calculating means 22 ... Width calculating means 24 ... Deviation judging means 26 ... Representative point correcting means 77, 86, 87 ... Forward vehicles (objects) 77a, 86a ... Center of gravity 87a ... End points

Claims (4)

Transmitting and receiving means for transmitting electromagnetic waves to a predetermined range around the host vehicle and receiving reflected waves from objects existing around the host vehicle;
Reflection point calculating means for calculating the position of the reflection point of the electromagnetic wave on the object;
Representative point calculation means for calculating the position of a representative point representing the position of the object based on the reflection point;
A relative relationship calculating means for calculating a relative relationship consisting of a relative position and a relative distance between the host vehicle and the object based on the representative point;
Relative speed calculation means for calculating a relative speed between the host vehicle and the object based on the relative position, a vehicle object detection device comprising:
Line segment recognition means for recognizing a line segment constituting the contour of the object based on the arrangement of the reflection points;
Representative point correction means for correcting the position of the representative point based on the relative distance,
The representative point calculating means, when the two line segments are recognized by the line segment recognizing means, when the end point of the object calculated as an intersection of the line segments is recognized as one line segment The center of gravity of the line segment is calculated as the representative point,
The vehicle object detection device, wherein the representative point correction means corrects the representative point from the end point to the barycentric point when the relative distance is a predetermined distance or more. Width calculating means for calculating the width of the object in the width direction of the host vehicle based on the reflection point;
Comparing the width of the object calculated in time series, and when the width of the object is reduced, a deviation determination means for determining that a part of the object has deviated outside the predetermined range,
The representative point correcting means determines the representative point when the relative speed is in a direction toward the host vehicle and the deviation determining means determines that a part of the object has deviated from the predetermined range. The vehicle object detection device according to claim 1, wherein a correction is made from the center of gravity to the end point.   The relative speed calculation means is configured to change the representative speed of the host vehicle when the representative point is changed from one of the center of gravity point and the end point to the other during the calculation of the relative position from the previous calculation of the relative position. The vehicle object detection device according to claim 1, wherein the relative speed in the width direction is not calculated. Width calculating means for calculating the width of the object in the width direction of the host vehicle based on the reflection point;
The relative speed calculation means is configured to calculate the width calculation means when the representative point is changed from one of the center of gravity point and the end point to the other from the previous calculation of the relative position to the current calculation of the relative position. 3. The vehicle according to claim 1, wherein the relative speed in the width direction of the host vehicle is calculated while correcting the relative position calculated last time based on the width of the object calculated by the step. Object detection device.

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