JP2006079346A - Vehicle surrounding object detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device detecting an object in the surroundings of a vehicle, capable of accurately finding position relation with the object even when a detection point from the same object to be originally grouped into the same group as an object showing one object is not correctly grouped. <P>SOLUTION: Position coordinates in each the detection point are detected about the object in front of a driver's own vehicle (step S1), the detection points satisfying a prescribed condition are unified to produce the group of the detection points in each the object, and the grouping is performed (step S4). The detection point satisfying a prescribed regrouping condition among the detection points not included in the group are unified in each the object. An X coordinate value after the regrouping is calculated on the basis of the respective position coordinates of the regrouped detection points and the detection points grouped by the grouping. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for detecting an object mounted on a vehicle and present around the vehicle.

  A method of detecting a relative positional relationship with another vehicle traveling in front of the host vehicle using a laser radar or the like is widely known. For example, in the apparatus disclosed in Patent Document 1, the irradiation range of the laser radar is divided for each predetermined angle, and any one of a plurality of distance data detected in each divided area is selected and used. To compress the distance data. Based on the distance data thus compressed, the relative position and the relative speed with respect to the host vehicle are obtained for the detection points in each region. Furthermore, when the relative positions and relative speeds of a plurality of detection points are within a certain range, the detection points are grouped into one group and processed as representing the same vehicle. In this way, the relative positional relationship with other vehicles is obtained.

JP 2001-343460 A

  In the apparatus disclosed in Patent Document 1, even if it is a detection point from the same other vehicle that should be grouped into the same group as originally representing one vehicle, it may not be correctly grouped due to a measurement error or the like. In such a case, there is a problem that the positional relationship with other vehicles cannot be obtained accurately.

  A vehicle surrounding object detection device according to the present invention includes a position detection unit that detects a relative position of an object around the host vehicle with respect to the host vehicle at one or a plurality of detection points, and a detection point in which the relative position is detected by the position detection unit. Out of the detection points that are not included in the group created by the grouping means for grouping the detection points that satisfy the predetermined grouping condition and creating a first group of detection points for each object. Re-grouping means for grouping detection points that satisfy the grouping condition and creating a second group of detection points for each object, and for each detection point grouped into the first and second groups by the grouping means and the re-grouping means, respectively. Position calculating means for obtaining the relative position of the object based on the relative position.

  According to the present invention, with respect to an object around the own vehicle, the relative position with respect to the own vehicle is detected at one or a plurality of detection points, and detection points satisfying a predetermined grouping condition are grouped to create a group of detection points for each object. By doing so, grouping is performed. Re-grouping is performed by collecting detection points that satisfy a predetermined re-grouping condition among detection points not included in the first group and creating a second group. Thus, the relative position of the object is obtained based on the relative positions of the detection points grouped into the first group by the previous grouping and the detection points grouped into the second group by the regrouping. Since it did in this way, even if it is a case where the detection point from the same other vehicle which should be grouped in the same group as what originally represents one vehicle is not correctly grouped, The positional relationship can be obtained accurately.

  FIG. 1 shows the configuration of a vehicle surrounding object detection device (hereinafter referred to as the present device) according to an embodiment of the present invention. This apparatus is mounted on a vehicle and includes a laser radar 1, a vehicle behavior detection unit 2, a calculation unit 3, and a vehicle control unit 4. The apparatus detects an object such as another vehicle (hereinafter simply referred to as an object) existing in front of the host vehicle by using these components, and controls the traveling of the host vehicle based on the detection result. Each component will be described below.

  The laser radar 1 is installed at the front end of the host vehicle, irradiates laser light toward the front of the host vehicle, and detects reflected light generated by the laser beam. The laser radar 1 is a kind of what is called a scanning laser radar, and can scan (scan) the laser light within a predetermined scanning range by changing the irradiation direction of the laser light.

  When an object exists within the scan range of the laser radar 1, the irradiated laser light is reflected by the object. At this time, since the irradiation direction is changed by the scanning of the laser beam, a plurality of reflection points are generated on the object. By detecting the reflected light by the laser radar 1 using the plurality of reflection points as detection points and measuring the time from when the laser light is irradiated to each detection point until the reflected light is detected, the own vehicle To the respective detection points are calculated. Further, the direction of each detection point with respect to the host vehicle is obtained from the irradiation direction of the laser light when the reflected light is detected. Based on the distance and direction of each detection point thus obtained, the relative position of the object ahead of the host vehicle with respect to the host vehicle is detected at each detection point. The detection result of the relative position at each detection point is output from the laser radar 1 to the calculation unit 3 as position information and reflection intensity information representing the measurement value at each detection point together with the intensity of the reflected light detected at each detection point. Is done.

  FIG. 2 is a diagram showing an example of mounting the laser radar 1 on the own vehicle. The laser radar 1 mounted near the center of the front end of the host vehicle 11 irradiates the laser beam in front of the host vehicle 11, that is, in the direction on the left side in the figure. The optical axis of the laser beam at this time is represented as an optical axis L. Also, the left and right coordinate axes with respect to the host vehicle 11 are defined as the X axis, the vertical coordinate axis is defined as the Y axis, and the longitudinal coordinate axis is defined as the Z axis. When the optical axis L and the Z axis coincide with each other, the laser beam is irradiated toward the front surface of the host vehicle 11. The origin position 11a of each coordinate axis is assumed to be fixed with respect to the host vehicle 11.

  The laser radar 1 can rotate the optical axis L within a predetermined angle in the left-right direction (around the Y axis) around the origin of each coordinate axis. Thereby, the irradiation direction of a laser beam changes horizontally within a predetermined angle. At this time, the surface along which the optical axis L rotates is called a scanning surface, and this scanning surface is equal to the horizontal plane (XZ plane). In this way, the laser radar 1 scans the laser beam within a predetermined scan range along the scanning surface.

  The vehicle behavior detection unit 2 acquires information (host vehicle travel information) for representing the travel state of the host vehicle by detecting the behavior of the host vehicle. The vehicle behavior detection unit 2 includes a wheel speed sensor that detects the wheel speeds of the left and right rear wheels, and a steering angle sensor that detects a steering angle. Then, the yaw rate and slip angle of the host vehicle calculated based on the sensor signals from these sensors are acquired as host vehicle travel information. The own vehicle travel information acquired by the vehicle behavior detection unit 2 is output to the calculation unit 3.

  The calculation unit 3 is configured by a microcomputer including a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an input / output I / F, and the like mounted in the host vehicle. The calculation unit 3 is based on the position information and reflection intensity information of each detection point output from the laser radar 1 and the own vehicle travel information output from the vehicle behavior detection unit 2, that is, the yaw rate and slip angle of the own vehicle. Thus, a process of detecting an object existing on the estimated course ahead of the host vehicle (hereinafter referred to as an object detection process) is executed. The result of the object detection process is output from the calculation unit 3 to the vehicle control unit 4. For example, the relative distance from the host vehicle to the object and the relative speed of the object with respect to the host vehicle are output from the calculation unit 3 to the vehicle control unit 4 as a result of the object detection process. The specific contents of the object detection process will be described later.

  The vehicle control unit 4 controls the host vehicle based on the result of the object detection process output from the calculation unit 3. For example, as described above, the relative distance from the host vehicle and the relative speed with respect to the host vehicle are output from the calculation unit 3 as the object detection processing result. When the relative distance is equal to or less than a predetermined value and the relative speed is equal to or greater than a predetermined value, the traveling speed of the host vehicle is reduced by controlling the engine speed, the brake operation, and the like of the host vehicle. . By doing in this way, based on the result of an object detection process, the own vehicle can be controlled so that the distance between the own vehicle and the other vehicle can be maintained at a certain level or more.

  Note that the content output as the object detection processing result from the calculation unit 3 to the vehicle control unit 4 and the content for controlling the host vehicle in the vehicle control unit 4 may be other than the above. For example, when the relative positional relationship between the host vehicle and the object is output from the calculation unit 3 to the vehicle control unit 4 and the relative positional relationship satisfies a predetermined condition, for example, when the traveling direction of the host vehicle is within a predetermined distance The vehicle control unit 4 can issue a warning to the driver.

  Next, the contents of the object detection process executed in the calculation unit 3 will be described by taking the case shown in FIG. 3 as an example. FIG. 3 shows how the laser radar 1 installed in the host vehicle 11 of FIG. 2 detects the objects A and B ahead of the host vehicle 11 existing in the scan range at time t−1 and time t, respectively. Is shown. Note that the X axis and the Z axis in FIG. 3 are defined in the same direction as in FIG.

  The laser radar 1 scans the laser beam within a predetermined scan range along the above-described scanning plane, and outputs position information and reflection intensity information obtained for each detection point to the calculation unit 3. Here, reflected light is detected at each of the detection points a, b, c, d, e, and f shown in FIG. 3 at time t−1, and the position information and reflection intensity information at each of these detection points is the laser. It is assumed that the signal is output from the radar 1 to the calculation unit 3. Hereinafter, the position coordinates of each detection point at time t−1 are represented as (Xω (t−1), Zω (t−1)), and the reflection intensity at each detection point is represented as Pω (t−1). However, any of a, b, c, d, e, and f enters ω. In FIG. 3, each detection point is shown in a circular range having a different size. This is for indicating the magnitude of the reflection intensity Pω (t−1) at each detection point. Actually, each detection point is located at the center of each circular range. For example, since the detection points b and d are larger in the circular range than the other detection points, the values of the reflection intensities Pb (t−1) and Pd (t−1) are the values of the other detection points. It can be seen that it has a larger value than the reflection intensity.

  The calculation unit 3 groups the detection points detected at time t−1 and groups the detection points representing the same object into one group. Here, the detection points c and f represent the object A, and the detection points a, b, d, and e represent the object B, and are grouped in the same group. Note that one detection point may be grouped.

When the detection points of the same object are grouped as described above, based on the position information and reflection intensity information of each detection point output from the laser radar 1, the objects A and B are used as parameters of each object at time t-1. The lateral width (width in the X-axis direction), position, relative velocity, and reflection intensity are respectively calculated. In the following, the horizontal width, position coordinates, relative speed, and reflection intensity of the object A at time t−1 are respectively expressed as follows.
Width of object A: WA (t−1)
Position coordinates of the object A: (XA (t-1), ZA (t-1))
Relative velocity of object A: VA (t−1)
Reflection intensity of object A: PA (t-1)

Similarly, the horizontal width, position coordinates, relative velocity, and reflection intensity of the object B at time t−1 are respectively expressed as follows.
Width of object B: WB (t-1)
Position coordinates of the object B: (XB (t-1), ZB (t-1)),
Relative velocity of object B: VB (t-1)
Reflection intensity of object B: PB (t−1)

  A specific grouping method for grouping the detection points as described above and a specific calculation method for calculating the parameters of each object will be described in detail below by taking the case at time t as an example. To do.

  Next, at time t, reflected laser light is detected for each of the detection points a to f shown in FIG. 3 in the same manner as at time t−1, and position information and reflection intensity information at each detection point are obtained. It is assumed that the laser radar 1 outputs to the calculation unit 3. Hereinafter, the position coordinates of each detection point at time t are represented as (Xω (t), Zω (t)) (where ω is any one of a to f), and the reflection intensity at each detection point is represented by Pω (t). It expresses.

When the position information and the reflection intensity information about the detection points a to f at the time t are input from the laser radar 1 to the calculation unit 3, the calculation unit 3 firstly calculates the position of the object A at the time t-1. Based on (XA (t−1), ZA (t−1)) and relative velocity VA (t−1), estimated coordinates (XA ′ (t), ZA ′ ( t)) is calculated by the following equations (1) and (2).
ZA ′ (t) = ZA (t−1) + VA (t−1) · cos (Slip) (1)
XA ′ (t) = XA (t−1) + VA (t−1) · sin (Slip)
+ ZA '(t) tan (Yaw) (2)

  In the above formulas (1) and (2), Yaw and Slip represent the yaw rate and slip angle of the host vehicle output from the vehicle behavior detector 2, respectively. That is, the position of the object A at the current time t is estimated by adding the deviation due to the slip angle of the host vehicle and the deviation due to the yaw rate to the position of the object A obtained at the previous time t-1.

Further, the estimated coordinates (XA ′ (t), ZA ′ (t)) of the position of the object B at time t are also calculated by the following equations (3) and (4) in the same manner as described above.
ZB ′ (t) = ZB (t−1) + VB (t−1) · cos (Slip) (3)
XB ′ (t) = XB (t−1) + VB (t−1) · sin (Slip)
+ ZB '(t) tan (Yaw) (4)

  When the positions of the objects A and B at the time t are estimated as described above, the detection points are grouped for each object based on the estimated coordinate values. For the object A, with respect to each detection point existing around the estimated coordinates calculated by the above equations (1) and (2), the reflection intensity of each detection point and the previous time t− A difference value from the reflection intensity calculated in 1 is calculated for each detection point. Then, the detection points whose calculated difference values are equal to or less than a predetermined value are grouped together as ones representing the same object A, thereby grouping the objects A.

Specifically, for the detection points whose position coordinates satisfy the following expressions (5) and (6), the detection points whose reflection intensity satisfies the expression (7) are assigned to the same group representing the object A. Group as included.
XA ′ (t) − (1/2) · WA (t−1) ≦ Xω (t)
≦ XA ′ (t) + (1/2) · WA (t−1) (5)
ZA ′ (t) − (1/2) · Z0 ≦ Zω (t)
≦ ZA ′ (t) + (1/2) · Z0 (6)
| Pω (t) −PA (t−1) | ≦ Pt1 (7)

  When grouping is performed on the object A as described above, a grouping range 40 as indicated by a broken line in FIG. The grouping range 40 is set in a range of a lateral width WA (t−1) and a front-rear width Z0 around the estimated coordinates (XA ′ (t), ZA ′ (t)) of the object A. Of the detection points located within the grouping range 40, detection points satisfying Expression (7) are grouped into the same group. A predetermined value is set in advance for Z0. Pt1 is a threshold value, and a predetermined value is set in advance.

  As described above, it is located within the grouping range 40, and further, the reflection intensity Pω (t) at the detection point and the reflection intensity of the previous object A, that is, the reflection intensity PA (t− at the previous representative detection point). The detection points having a difference | Pω (t) −PA (t−1) | with respect to 1) equal to or less than a predetermined threshold value Pt1 are grouped together as one representing the object A. At this time, as described above, one detection point may be grouped. The representative detection points will be described later.

Similarly, the object B is also grouped for each detection point existing around the estimated coordinates represented by the above formulas (3) and (4). Specifically, among the detection points whose position coordinates satisfy the following expressions (8) and (9), those whose reflection intensity satisfies the expression (10) are grouped as being included in the same group representing the object B. .
XB ′ (t) − (1/2) · WB (t−1) ≦ Xω (t)
≦ XB ′ (t) + (1/2) · WB (t−1) (8)
ZB ′ (t) − (1/2) · Z0 ≦ Zω (t)
≦ ZB ′ (t) + (1/2) · Z0 (9)
| Pω (t) −PB (t−1) | ≦ Pt1 (10)

  When grouping is performed on the object B as described above, a grouping range 50 as indicated by a broken line in FIG. The grouping range 50 is set in a range of a lateral width WB (t−1) and a front-rear width Z0 with the estimated coordinates (XB ′ (t), ZB ′ (t)) of the object B as the center. Of the detection points located within the grouping range 50, detection points satisfying the expression (10) are grouped into the same group. Z0 and Pt1 are the same as those in the above-described formulas (6) and (7), and predetermined values are set in advance.

  As described above, the detection points that are located in the grouping range 50 and whose reflection intensity time variation | Pω (t) −PB (t−1) | is equal to or less than the predetermined threshold value Pt1 are detected. The objects B are grouped into one group. Also at this time, as described above, one detection point may be grouped.

  In this way, at the time t, the detection points are grouped based on the estimated coordinate values of the objects A and B. Here, it is assumed that only the detection point c is grouped as representing the object A and the detection point f is not grouped as representing the object A by the above formulas (5) to (7). In addition, it is assumed that the detection points a, b, and d are grouped into the same group as those representing the object B, and the detection point e is not grouped as one representing the object B according to the equations (8) to (10). As described above, even if the detection points are supposed to be grouped into one group, some of the detection points are out of the grouping range due to the influence of noise or measurement error.

  After the detection points are grouped as described above, the lateral width, position coordinates, relative velocity, and reflection intensity are calculated as parameters at time t for each of the object A and the object B.

For the object A, the lateral width WA (t), the position coordinates (XA (t), ZA (t)), the relative velocity VA (t), and the reflection intensity PA (t) at time t are expressed by the following equations, respectively. calculate.
WA (t) = MAX {Xω (t)} − MIN {Xω (t)} (11)
XA (t) = 1/2 · [MAX {Xω (t)} + MIN {Xω (t)}] (12)
ZA (t) = R1MAX {Zω (t)} (13)
VA (t) = ZA (t) −ZA (t−1) (14)
PA (t) = R1MAX {Pω (t)} (15)

  In the above formulas (11) and (12), MAX {Xω (t)} and MIN {Xω (t)} are the maximum and minimum X coordinate values of the detection points grouped in the same group. Respectively. Here, since only the detection point c is grouped as representing the object A, MAX {Xω (t)} = MIN {Xω (t)} = Xc (t). By substituting this into the equations (11) and (12), the lateral width of the object A at time t can be calculated as WA (t) = 0, and the X coordinate value can be calculated as XA (t) = Xc (t). it can. When only one detection point is grouped in this way, the horizontal width WA (t) may be set to a predetermined value without setting it to 0. For example, the width of change when scanning the laser radar 1 may be set as the value of the lateral width WA (t).

In the above equations (13) and (15), R1MAX {Zω (t)} and R1MAX {Pω (t)} are expressed by the following equation (16) among the detection points grouped in the same group. The Z coordinate and the reflection intensity of the largest reliability judgment value R1 (t) represented are respectively represented.
R1 (t) = Pω (t) (16)

  From the above equation (16), the reliability judgment value R1 (t) is obtained for each detection point representing the object A. Thereby, the reliability of each relative position is calculated about each of the detection points put together in one group. Here, the reliability judgment value R1 (t) according to the equation (16) is the reflection intensity Pω (t) at each detection point. That is, among the detection points in the same group representing the object A, the Z coordinate and the value of the reflection intensity of the highest reflection intensity are selected in the equations (13) and (15), and the object A is represented on behalf of each detection point. Z coordinate and reflection intensity. Hereinafter, such a detection point is referred to as a representative detection point of the object A.

  Here, since only the detection point c is grouped as representing the object A, the detection point c becomes the representative detection point of the object A. As a result, according to the equations (13) and (15), the Z coordinate value of the object A at time t is calculated as ZA (t) = Zc (t), and the reflection intensity is calculated as PA (t) = Pc (t). .

Similarly to the above for the object B, the lateral width WB (t), the position coordinates (XB (t), ZB (t)), the relative velocity VB (t) and the reflection intensity PB (t) at time t are It is calculated by the following formula.
WB (t) = MAX {Xω (t)} − MIN {Xω (t)} (17)
XB (t) = 1/2 · [MAX {Xω (t)} + MIN {Xω (t)}] (18)
ZB (t) = R1MAX {Zω (t)} (19)
VB (t) = ZA (t) −ZA (t−1) (20)
PB (t) = R1MAX {Pω (t)} (21)

  In the above equations (17) and (18), MAX {Xω (t)} and MIN {Xω (t)} are the detections grouped in the same group as in the above equations (11) and (12). The maximum and minimum values of the X coordinate values of the points are respectively shown. Here, in FIG. 5, among the detection points a, b and d of the same group representing the object B, the detection point a is located at the uppermost position in the figure, and the detection point d is located at the lowermost position in the figure. . In FIG. 5, the X axis and the Z axis are defined in the same direction as in FIG. 3 and FIG. 4, and the X coordinate value is larger as the detection point is located above the paper surface. Therefore, it can be seen that the X coordinate value Xa (t) of the detection point a is larger than the other detection points, and the X coordinate value Xd (t) of the detection point d is smaller than the other detection points. Therefore, MAX {Xω (t)} = Xa (t) and MIN {Xω (t)} = Xd (t). By substituting this into the equations (17) and (18), the lateral width of the object B at time t is WB (t) = Xa (t) −Xd (t), and the X coordinate value is XB (t) = 1 / 2 · {Xa (t) + Xd (t)}, respectively.

  In the above equations (19) and (21), R1MAX {Zω (t)} and R1MAX {Pω (t)} are grouped into the same group as in the above equations (13) and (15). Among the detection points, the Z coordinate and the reflection intensity of the detection point having the highest reliability judgment value R1 (t) represented by the above equation (16), that is, the reflection intensity is the highest, respectively. In the following, among the detection points grouped for the object B, the detection point with the highest reflection intensity selected in the equations (19) and (21) is referred to as a detection representative detection point for the object B.

  The manner in which the representative detection point of the object B is selected will be described with reference to FIG. In FIG. 5, the detection points a, b, and d are all within the grouping range 50 and are grouped into the same group representing the object B. Here, the size of the circular range at each detection point in FIG. 5 represents the value of the reflection intensity Pω (t) at that detection point, as in FIGS. 3 and 4. In FIG. 5, the detection point b has the largest circular range, and the reflection intensity Pb (t) of the detection point b is the reflection intensity Pa (t) of another detection point a or the reflection intensity of the detection point d. It can be seen that it is larger than Pd (t). That is, of the detection points a, b, and d in the same group representing the object B, the detection point b has the highest reliability judgment value R1 (t). At this time, the detection point b is set as a representative detection point of the object B. As a result, according to the equations (19) and (21), the Z coordinate value of the object B at time t is calculated as ZB (t) = Zb (t), and the reflection intensity is calculated as PB (t) = Pb (t). .

  As described above, each parameter (width) of object A and object B at time t is calculated using the calculation result at the previous time t-1 and the measurement value of each detection point grouped at the current time t. , Position coordinates, relative velocity and reflection intensity) are calculated. Note that each parameter is calculated in the same manner at other times. For example, when each parameter is calculated at time t-1, the calculation result at the previous time t-2 and the detection value for each detection point at the current time t-1 are used.

  Since there is no previous calculation result for a newly detected object, each parameter is calculated using only the detection value of the detection point at that time. Specifically, among the detected detection points, detection points that do not satisfy any of the expressions (5) and (6) or the expressions (8) and (9), that is, the object A or B detected last time. Detection points that are not located in any of the grouping ranges are processed as detection points that represent new objects, and those detection points that are located within a certain range are combined into one new object. Is grouped to represent By using the equations (11) to (13) and (15) for each detection point thus grouped, the lateral width, position coordinates, and reflection intensity of the new object are calculated. In addition, since the relative speed of the new object cannot be calculated by the equation (14), for example, an average value of the relative speeds of the grouped detection points may be used.

  By calculating each parameter as described above, the object A and the object B are detected in this apparatus. However, even detection points that should originally be grouped as representing the object A or the object B, such as the detection points f and e, may not be correctly grouped due to a measurement error or the like. In such a case, an accurate calculation result may not be obtained particularly for the width and X coordinate value of each object. Therefore, after correctly regrouping these detection points by performing regrouping described below, the lateral widths WA (t) and WB (t) of the objects A and B and the X coordinate values XA (t) and XB By calculating (t), a correct calculation result is obtained.

  In the regrouping, a predetermined regrouping range different from the grouping range set in the previous grouping is set first. Then, processing for extracting detection points included in the re-grouping range from detection points that were not grouped in the previous grouping is performed. In the following description, the detection points extracted by this processing are referred to as regrouping candidate detection points.

For the object A, the regrouping range is set by the following equations (22) and (23).
XA ′ (t) − {2T1 + (1/2) · WA (t−1)} ≦ Xω (t)
≦ XA ′ (t) + {2T1 + (1/2) · WA (t−1)} (22)
ZA (t) −T3 ≦ Zω (t) ≦ ZA (t) + T2 (23)

In the above equation (22), the value of T1 is represented by the following equations (24) and (25).
When WAλ−WA (t) ≧ Wt1, T1 = α (24)
When WAλ−WA (t) <Wt1, T1 = β (25)
Where α> β

  In the above formulas (24) and (25), WAλ represents the average value of the lateral width of the object A obtained in the past at each time up to the previous time (t−1). A predetermined value is set in advance as the threshold value Wt1. α and β represent predetermined lengths predetermined in the X-axis direction. For example, α = 0.9 m is set for α, which is about half the width of a normal vehicle, and β = 0.3 m is set for β, which is a sufficiently small value. Thus, the size of the regrouping range is changed based on the average width WAλ obtained in the past and the lateral width WA (t) obtained this time.

  When the expression (24) is satisfied and the current width WA (t) is smaller than the average value WAλ of the past width and the difference is larger than the predetermined threshold value Wt1, the above grouping is correct. It is considered that there is a high possibility that a detection point of the object A that has not been grouped exists. Therefore, in such a case, by setting T1 = α and setting the lateral width of the regrouping range to be large according to the width of the vehicle as described above, the object A is in another vehicle traveling in front of the host vehicle. In some cases, detection points originally included in other vehicles but not correctly grouped can be extracted as regrouping candidate detection points. Further, when Expression (25) is satisfied, T1 = β is set, and the lateral width of the re-grouping range is set to be sufficiently narrower than the vehicle width as described above. A detection point is prevented from being erroneously set as a regrouping candidate detection point.

In the above equation (23), the values of T2 and T3 differ depending on the value of Xω (t) and are represented by the following equations (26) to (28).
(A) Central part of horizontal range XA ′ (t) − (1/2) · WA (t−1) ≦ Xω (t)
≦ XA ′ (t) + (1/2) · WA (t−1)
When T2 = T3 = γ (26)
(A) Between the central portion and the end portion XA ′ (t) − {(T1 + 1/2) · WA (t−1)} ≦ Xω (t)
<XA '(t)-(1/2) .WA (t-1)
Or XA ′ (t) + (1/2) .WA (t−1) <Xω (t)
≤XA '(t) + {(T1 + 1/2) .WA (t-1)}
When T2 = δ, T3 = ε (27)
(C) Left and right end portions XA ′ (t) − {(2T1 + 1/2) · WA (t−1)} ≦ Xω (t)
<XA '(t)-{(T1 + 1/2) .WA (t-1)}
Or XA ′ (t) + {(T1 + 1/2) · WA (t−1)} <Xω (t)
≦ XA ′ (t) + {(2T1 + 1/2) · WA (t−1)}
When T2 = T3 = ζ (28)
However, γ>δ>ε> ζ

  In the above formulas (26) to (28), γ, δ, ε, and ζ each represent a predetermined length that is predetermined in the Z-axis direction. Is set. (A) The central portion of the lateral range corresponds to a portion within the vehicle width range at the current predicted position of the other vehicle when the object A is another vehicle traveling in front of the host vehicle. Therefore, in this part, it is considered that no other object basically exists in the range within the total length of the vehicle in the front-rear direction (Z-axis direction) of the object A. Therefore, γ = 5.0 m is set as a value corresponding to the total length of the large-sized ordinary vehicle. By setting the value of γ in accordance with the total length of the vehicle in this way, a plurality of detection points having different Z coordinate values are received by receiving reflected light from other than the back surface portion such as the side surface portion of the object A which is another vehicle. If any of the detected points is not grouped, the detected point is included in the regrouping range.

  (C) The left and right end portions correspond to the left and right end portions in the horizontal direction of the re-grouping range set for the object A. For this portion, for example, a relatively small value of ζ = 0.5 m is set. As a result, if only one detection point on the side of the vehicle, for example, the detection point on the left side, can be grouped, the detection point on the opposite side, that is, the detection point on the right side, only the detection point existing in the vicinity of the same Z coordinate value is re-grouped And other detection points are not included in the re-grouping range. By doing in this way, the detection point from the vehicle of an adjacent lane is not accidentally regrouped.

  (B) Between the central part and the end part corresponds to a part between the central part of the horizontal range (A) and the left and right end parts of (C) in the re-grouping range set for the object A. . For this portion, a value between γ and ζ is set, and for the value δ of T2 representing the range in the forward direction (positive direction of the X axis), the range in the backward direction (negative direction of the X axis) is set. A value larger than the value ε of T3 to be expressed is set. For example, δ = 3.5 m and ε = 2.0 m are set. As a result, when there is a detection point that is not correctly grouped due to a measurement error generated near the vehicle end, the detection point is included in the re-grouping range. At this time, a larger value is set for the front direction than for the rear direction so that detection points from the vehicles in the adjacent lane that appear from the front side of the object A are not erroneously regrouped.

  As described above, the shape of the regrouping range is set so as to decrease stepwise as the distance from the center increases.

Note that, similarly to the object A, the regrouping range is set for the object B by the following equations (29) and (30).
XB ′ (t) − {2T1 + (1/2) · WB (t−1)} ≦ Xω (t)
≦ XB ′ (t) + {2T1 + (1/2) · WB (t−1)} (29)
ZB (t) −T3 ≦ Zω (t) ≦ ZB (t) + T2 (30)

In the above equation (29), the value of T1 is expressed by the following equations (31) and (32), as in the case of the object A. WBλ represents the average value of the lateral width of the past object B obtained at each time up to time (t−1) as in WAλ, and the threshold values Wt1, α, and β are as described above. Represents the same value.
When WBλ−WB (t) ≧ Wt1, T1 = α (31)
When WBλ−WB (t) <Wt1, T1 = β (32)
Where α> β

Further, in the above equation (30), the values of T2 and T3 are expressed by the following equations (33) to (35) as in the case of the object A. Note that γ, δ, ε, and ζ all represent the same values as described above.
(A) Horizontal range center portion XB ′ (t) − (1/2) · WB (t−1) ≦ Xω (t)
≦ XB ′ (t) + (1/2) · WB (t−1)
When T2 = T3 = γ (33)
(A) Between the central portion and the end portion XB ′ (t) − {(T1 + 1/2) · WB (t−1)} ≦ Xω (t)
<XB ′ (t) − (1/2) · WB (t−1)
Or XB ′ (t) + (1/2) · WB (t−1) <Xω (t)
≦ XB ′ (t) + {(T1 + 1/2) · WB (t−1)}
When T2 = δ, T3 = ε (34)
(C) Left and right end portions XB ′ (t) − {(2T1 + 1/2) · WB (t−1)} ≦ Xω (t)
<XB ′ (t) − {(T1 + 1/2) · WB (t−1)}
Or XB ′ (t) + {(T1 + 1/2) · WB (t−1)} <Xω (t)
≦ XB ′ (t) + {(2T1 + 1/2) · WB (t−1)}
When T2 = T3 = ζ (35)
However, γ>δ>ε> ζ

  An example of the regrouping range set for each of the objects A and B as described above is shown in FIG. (A) shows the regrouping range of the object A, and (b) shows the regrouping range of the object B. Here, for object A, the value of horizontal width WA (t) satisfies the above equation (24) and is set to T1 = α. For object B, the value of horizontal width WB (t) is It is assumed that T1 = β is set to satisfy Expression (32). At this time, the regrouping range 41 is set large for the object A as shown in (a), and the regrouping range 51 is set small for the object B as shown in (b). The grouping ranges 40 and 50 are grouping ranges set by the previous grouping as described above. As shown in FIG. 6, the detection point f is included in the re-grouping range 41, and the detection point e is included in the re-grouping range 51.

  As described above, the regrouping ranges are set for the object A and the object B, respectively. The position coordinates (Xω (t), Zω (t)) do not satisfy any of the above-described formulas (5) and (6), or (8) and (9). Among the detection points that have not been grouped, detection points that satisfy any of the above formulas (22) and (23) or formulas (29) and (30) are extracted as regroup candidate detection points. As a result, the detection point f is extracted as a regrouping candidate detection point for the object A, and the detection point e is extracted as a regrouping candidate detection point for the object B.

  Next, from the regrouping candidate detection points extracted as described above, the detection points to be actually regrouped are selected and combined. At this time, as described above, when it is considered that there is a high possibility that there is a detection point that has not been correctly grouped in the previous grouping, a wider regrouping range is set than in the case where the detection point is not. Therefore, in either case, in order to appropriately select the detection point to be regrouped from the regrouping candidate detection points, detection to be regrouped according to the difference in the set regrouping range as described below. Try changing the way points are selected.

  The case of the object A will be described as an example. When a relatively wide regrouping range is set by satisfying the equation (24), among the regrouping candidate detection points included in the regrouping range, Only the detection points moving in the same direction as the movement direction obtained by the previous grouping for the object A corresponding to the regrouping range are selected. The detection points thus selected are collected as detection points that are actually regrouped.

Specifically, when the value of the lateral width WA (t) of the object A calculated by the previous grouping result satisfies the condition of Expression (24), the relative of the object A calculated by the previous grouping result A detection point at which the difference between the speed VA (t) and the relative speed Vω (t) is equal to or smaller than a predetermined value is selected as a detection point to be actually regrouped. At this time, only the detection points satisfying the following formula (36) among the above-mentioned regrouping candidate detection points are selected as detection points to be regrouped. In Expression (36), a predetermined value is set in advance for Vt1, which is the threshold value.
| VA (t) −Vω (t) | ≦ Vt1
And VA (t) · Vω (t)> 0 (36)
However, Vω (t) = Zω (t) −Zω (t−1)

  On the other hand, when a relatively narrow regrouping range is set by satisfying Expression (25), all of the regrouping candidate detection points included in the regrouping range are set regardless of Expression (36) above. Select and collect as detection points to actually regroup.

For the object B as well, the detection point to be regrouped is selected from the regrouping candidate detection points as in the case of the object A. That is, when the value of the width WB (t) of the object B calculated based on the previous grouping result satisfies the condition of Expression (31), only the regrouping candidate detection points that satisfy Expression (37) below are actually used. Select as a detection point to regroup. When the value of WB (t) satisfies the condition of Expression (32), all of the regrouping candidate detection points are selected as detection points for regrouping.
| VB (t) −Vω (t) | ≦ Vt1
And VB (t) · Vω (t)> 0 (37)

  As described above, since the width WA (t) of the object A satisfies the equation (24), the object A that satisfies the equation (36) among the regrouping candidate detection points is regrouped. Selected as detection point. At this time, the detection point f is selected as a detection point to be regrouped. Further, since the value of the width WB (t) for the object B satisfies Expression (32), all the regrouping candidate detection points are selected as detection points that are actually regrouped. Therefore, the detection point e is selected as a detection point to be regrouped. The detection points thus selected are grouped for each object, and regrouping is performed.

As described above, when the detection points to be regrouped are grouped into groups for each object, each detection point included in the group of detection points by the previous grouping and the group of detection points grouped by regrouping The horizontal width WAr (t) and the X coordinate value XAr (t) at time t after the regrouping are obtained for the object A based on the position coordinates with each detection point included in the following expression (38), (39). ) Is calculated.
WAr (t) = MAX {Xω (t)} − MIN {Xω (t)} (38)
XAr (t) = 1/2 · [MAX {Xω (t)} + MIN {Xω (t)}] (39)

  In the above equations (38) and (39), MAX {Xω (t)} and MIN {Xω (t)} are determined by the detection point c grouped by the previous grouping and the regrouped detection point f. Calculated. Here, in FIG. 4, the detection point c and the detection point f are located further upward in the figure. In FIG. 4, the X axis and the Z axis are defined in the same direction as in FIG. 3, and the X coordinate value Xc (t) of the detection point c is larger because the X coordinate value is larger at the detection point located above the paper surface. It can be seen that it is larger than the X coordinate value Xf (t) of the detection point f. Therefore, MAX {Xω (t)} = Xc (t) and MIN {Xω (t)} = Xf (t). By substituting this into equations (38) and (39), the lateral width of the object A at time t after regrouping is WAr (t) = Xc (t) −Xf (t), and the X coordinate value is XAr ( t) = 1/2 · {Xc (t) + Xf (t)}.

Similarly for the object B, the horizontal width WBr (t) and the X coordinate value XBr (t) at the time t after the regrouping are calculated by the following equations (40) and (41).
WBr (t) = MAX {Xω (t)} − MIN {Xω (t)} (40)
XBr (t) = 1/2 · [MAX {Xω (t)} + MIN {Xω (t)}] (41)

  In the above equations (40) and (41), MAX {Xω (t)} and MIN {Xω (t)} are regrouped with the detection points a, b and d grouped by the previous grouping. Calculated by the detection point e. Here, in FIG. 4, since the detection point e is located further down than the detection points a, b, and d, the X coordinate value Xe (t) of the detection point e is the value of the other detection points. It can be seen that it is smaller than the X coordinate value. Therefore, MIN {Xω (t)} = Xd (t). Note that MAX {Xω (t)} is expressed as MAX {Xω (t)} = Xa (t) as in the previous grouping. By substituting this into the equations (40) and (41), the horizontal width of the object B at time t after regrouping is WBr (t) = Xa (t) −Xe (t), and the X coordinate value is XBr ( t) = 1/2 · {Xa (t) + Xe (t)}.

  As described above, the lateral widths and X coordinate values of the regrouped objects A and B are calculated by the equations (38) to (41), respectively. Then, the lateral width WA (t) calculated by the above-described equation (11) and the lateral width WB (t) calculated by the equation (17) are respectively replaced with the lateral width WAr (t) and WBr after the regrouping. (T) is used as the lateral width of the objects A and B at time t. Further, the X coordinate value XA (t) calculated by the equation (12) and the X coordinate value XB (t) calculated by the equation (18) are respectively replaced, and the re-grouped X coordinate value XAr ( t) and XBr (t) are used as the X coordinate values of the objects A and B at time t. In this way, a correct calculation result can be obtained even when there is a detection point that has not been correctly grouped in the previous grouping.

  However, if regrouping is performed as described above, detection points of different objects may be erroneously regrouped. In that case, a correct calculation result cannot be obtained. Therefore, if the error in the calculation result caused by incorrect regrouping is considered to have a large effect on the control of the host vehicle, the calculation is performed in the previous grouping regardless of the calculation result of the above regrouping. The horizontal width and the X coordinate value are used as they are. For example, when the vehicle control unit 4 is executing control of the host vehicle by satisfying the conditions as described above, or when it is determined that the vehicle control unit 4 is performing an overtaking operation overtaking another vehicle ahead of the host vehicle, This corresponds to the case where the influence on the control of the host vehicle is considered to be large.

  Even if it is during the control of the host vehicle or the overtaking operation as described above and the influence on the control of the host vehicle is considered to be large, the grouping is correctly performed in the previous grouping as described above. When it is considered that there is a high possibility that a detection point that did not exist is present, the estimated X coordinate value based on the previous horizontal width and the previous calculation result is used rather than using the horizontal width and X coordinate value calculated in the previous grouping as they are. It is considered that there is less error with respect to the correct lateral width and X coordinate value when using. Therefore, in such a case, instead of the horizontal width and X coordinate value calculated in the previous grouping, the previous horizontal width and the estimated X coordinate value based on the previous calculation result are also used this time.

  However, even if it is considered that there is a high possibility that there is a detection point that is being grouped correctly in the previous grouping during the overtaking operation, a part of the object is out of the scan range of the laser radar 1. Sometimes, if the estimated X coordinate value based on the previous calculation result is used as described above, the influence on the control of the host vehicle may be increased. This will be described below using the example shown in FIG.

  In the object C shown in FIG. 7, detection points g and h are detected at time t−1, and the position of the point 71 is obtained as the position of the object C at time t−1 based on the grouping result. Next, at time t, when the position of the point 72 is the actual position of the object C, it is assumed that only the detection point g is detected because the detection point h goes out of the boundary line 70 of the scan range. . In this case, the position of the object C at time t is calculated as the position of the detection point g. At this time, based on the calculation result at time t−1, the position of the point 73 is estimated as the position at time t. .

  In the above state, the movement vector 74 indicating the moving direction of the object C is set from the point 71 toward the point 73. At this time, since the movement vector 74 is directed in the direction of the host vehicle, there is a possibility that a control that prevents the overtaking operation of the object C with respect to the host vehicle is erroneously activated. In such a case, the influence on the control of the own vehicle is increased.

  Therefore, even if it is considered that there is a high possibility that there is a detection point that is being grouped correctly in the previous grouping during the overtaking operation, a part of the object is not laser radar as in the example of FIG. When the state is outside the scan range of 1, the horizontal width and the X coordinate value based on the previous grouping calculation result are used as they are.

The contents of the processing performed after the regrouping described above will be specifically described first from the case of the object A. As described above, when the vehicle control unit 4 is controlling the host vehicle with respect to the object A, or when it is determined that the host vehicle is in the process of overtaking the object A, the width after regrouping Use of WAr (t) and the X coordinate value XAr (t) is prohibited. For example, in the following cases (a) to (d), it is determined that the host vehicle is in the process of overtaking the object A. The conditions (a) to (d) are merely examples, and it may be determined that the host vehicle is in the process of overtaking the object A using other conditions.
(A) When the speed of the host vehicle is higher than that of the object A, that is, when VA (t) <0 and the host vehicle is taking out the blinker, the lateral width WA (t) of the object A becomes narrower. Or when the X coordinate value XA (t) is deviated (b) When the speed of the host vehicle is higher than that of the object A, that is, VA (t) <0, and the steering more than a predetermined amount is performed. When the lateral width WA (t) of the object A becomes narrower or the X coordinate value XA (t) deviates (c) the accelerator of the host vehicle is being depressed, and the host vehicle further When the width WA (t) of the object A is narrowed or the X coordinate value XA (t) is deviated while taking out the blinker, (d) the accelerator of the host vehicle is being depressed. Further, when the steering more than a predetermined amount is performed, the lateral width WA (t of the object A If you have come to the case has been and X coordinate values XA (t) is a deviation narrow

  As described above, use of the lateral width WAr (t) and the X coordinate value XAr (t) after regrouping is prohibited, and when the above equation (24) is not satisfied, the above equation (11 ) And the X-coordinate value XA (t) calculated by the equation (12) are used as they are without being replaced with other values.

When Expression (24) is satisfied and the following Expression (42) is also satisfied, the calculated width WA (t-1) is replaced with the calculated width WA (t), and the width WA (t-1) at time t-1 is calculated this time. Also used as the horizontal width at time t. Further, the estimated X coordinate value XA ′ (t) obtained by the equation (2) is used as the X coordinate value at time t instead of the X coordinate value XA (t). However, in equation (42), θt represents a threshold value that is set with respect to the angle in the lateral direction when looking forward from the host vehicle, and this is predetermined in the vicinity of the scan range of the laser radar 1. A predetermined value is set. For example, θt = 60 ° is set.
| Tan ⁻¹ {XA (t) / ZA (t)} | <θt (42)

  On the other hand, when the expression (24) is satisfied but the expression (42) is not satisfied, the lateral width WA (t) calculated by the above expression (11) and the expression (12) are calculated. The X coordinate value XA (t) is used as it is without being replaced with another value.

  Similarly, for the object B, when the vehicle control unit 4 controls the own vehicle with respect to the object B, or when it is determined that the object B is in an overtaking operation, that is, When the cases a) to (d) apply, the horizontal width WBr (t) and the X coordinate value XB (t) after regrouping are not used. If the above equation (31) is not satisfied at this time, the lateral width WB (t) calculated by the above equation (17) and the X coordinate value XB (t) calculated by the equation (18) It is used as it is without replacing with the value of.

When the expression (31) is satisfied and the following expression (43) is also satisfied, the calculated width WB (t) is replaced with the calculated width WB (t), and the width WB (t-1) at time t-1 is calculated this time. Also used as the horizontal width at time t. Further, the estimated X coordinate value XB ′ (t) obtained by the equation (4) is used as the X coordinate value at time t instead of the X coordinate value XB (t).
| Tan ⁻¹ {XB (t) / ZB (t)} | <θt (43)

  When the expression (31) is satisfied but the expression (43) is not satisfied, the lateral width WB (t) calculated by the above expression (17) and the X coordinate calculated by the expression (18) The value XB (t) is used as it is without being replaced with another value.

  As described above, the horizontal widths and X coordinate values of the objects A and B at the time t are calculated based on the result of the regrouping process. For other parameters (Z coordinate value, relative velocity, reflection intensity), the calculation results before regrouping are used as they are. In addition, each parameter is similarly calculated at other times. For example, when each parameter is calculated at time t-1, the calculation result at the previous time t-2 and the detection value for each detection point at the current time t-1 are used.

  By calculating each parameter as described above, the object A and the object B are detected in this apparatus. Among the detected objects, an object moving with a predetermined width (for example, 1.0 m) or more is extracted as a vehicle candidate. Further, even when the horizontal width is equal to or smaller than a predetermined value, if there are a plurality of objects moving in the same direction adjacent to each other within a predetermined distance, they are grouped and extracted as one vehicle candidate. The previous object information is updated with the vehicle candidate information extracted in this manner.

  Further, the estimated course of the host vehicle is calculated from the yaw rate and slip angle calculated by the vehicle behavior detection unit 2. Then, based on the estimated course and the object information updated as described above, an object such as another vehicle existing on the estimated course of the host vehicle is specified, and the relative distance and the relative speed are used as the object detection processing result. Output to the vehicle control unit 4. As described above, the object detection process is executed in the calculation unit 3.

  FIG. 8 shows a flowchart of a processing procedure when the calculation unit 3 performs the object detection process. This flowchart is started when the host vehicle is traveling. In step S1, the laser radar 1 scans laser light within the scan range with respect to the front of the host vehicle, and obtains reflected laser light from the objects A and B existing in front. Thereby, the distance and direction from the own vehicle to the detection points a to f are detected, and the position information (Xω (t), Zω (t)) and reflection intensity of each detection point from the laser radar 1 to the calculation unit 3 are detected. Information Pω (t) is output.

  In step S2, the vehicle behavior detector 2 detects the wheel speed and steering angle of the left and right rear wheels of the host vehicle, and calculates the yaw rate and slip angle as host vehicle travel information. As a result, the yaw rate Yaw and slip angle Slip of the host vehicle are output from the vehicle behavior detection unit 2 to the calculation unit 3.

  In step S3, the calculation unit 3 calculates the estimated positions of the objects A and B. Here, the previous coordinate values (XA (t−1), ZA (t−1)) and relative speed VA (t−1) of the object A, and the yaw rate output from the vehicle behavior detection unit 2 in step S2 Based on Yaw and the slip angle Slip, the estimated coordinates (XA ′ (t), ZA ′ (t)) of the object A are calculated by using the expressions (1) and (2) described above. Further, the previous coordinate value (XB (t−1), ZB (t−1)) and relative speed VB (t−1) of the object B, and the yaw rate output from the vehicle behavior detecting unit 2 in step S2 are also used. Based on Yaw and the slip angle Slip, the estimated coordinates (XB ′ (t), ZB ′ (t)) of the object B are calculated by using the equations (3) and (4) described above.

  In step S4, the object A and the object B are grouped separately. Here, the detection points that satisfy the conditions of the expressions (5) to (7) are grouped as being included in the same group representing the object A, and the detection points that satisfy the conditions of the expressions (8) to (10) are grouped. Are grouped as being included in the same group. In the next step S5, the reliability judgment value R1 (t) is calculated for each detection point of the object A and the object B grouped in step S4 using the equation (16).

  In step S6, the detection point with the largest reliability judgment value R1 (t) calculated in step S5 is selected as the representative detection point. Here, as described above, the detection point c is selected as the representative detection point of the object A, and the detection point c is selected as the representative detection point of the object B. In the next step S7, according to the equations (11) to (15), the lateral width WA (t), the position coordinates (XA (t), ZA (t)), the relative velocity VA ( t) and the reflection intensity PA (t) are calculated. Further, according to the equations (17) to (21), as the parameters of the object B at the time t, the lateral width WB (t), the position coordinates (XB (t), ZB (t)), the relative velocity VB (t), and the reflection The intensity PB (t) is calculated.

  In step S8, a regrouping range is set. Here, the re-grouping range in the X-axis direction is set for the object A by Equation (22), and the re-grouping range in the Z-axis direction is set by Equation (23). At this time, the size T1 of the re-grouping range in the X-axis direction is changed according to the value of the horizontal width WA (t) by the equations (24) and (25). Further, the sizes T2 and T3 of the re-grouping range in the Z-axis direction are changed according to the positions in the X-axis direction using the equations (26) to (28). Similarly, for the object B, the regrouping range is set by the equations (29) and (30).

  In step S9, detection points included in the regrouping range set in step S8 are extracted as regrouping candidate detection points from the detection points that are not grouped in the grouping process in step S4. Here, the detection point f is extracted as a regrouping candidate detection point for the object A, and the detection point e is extracted as a regrouping candidate detection point for the object B.

  In step S10, detection points to be regrouped are selected from the regrouping candidate detection points extracted in step S9. At this time, for the object A, the selection method of the detection points to be regrouped is switched according to the value of the width WA (t) by the equations (24) and (25). Here, since the width WA (t) satisfies the condition of Expression (24), a regrouping candidate detection point that satisfies Expression (36) is selected as a detection point to be regrouped. Similarly, for the object B, the selection method of the detection points to be regrouped is switched according to the value of the horizontal width WB (t) by the equations (31) and (32). Here, since the width WB (t) satisfies the condition of Expression (32), all the regrouping candidate detection points are selected as detection points to be regrouped. In step S10, the detection point f is selected as a detection point for regrouping the object A, and the detection point e is selected as a detection point for regrouping the object B.

  In step S11, the detection points grouped in step S4 and the detection points regrouped in step S10 are combined to calculate a parameter after regrouping. Here, the lateral width WAr (t) and the X coordinate value XAr (t) are calculated as parameters after the regrouping of the object A at time t by the equations (38) and (39). In addition, the horizontal width WBr (t) and the X coordinate value XBr (t) are calculated as parameters after regrouping of the object B at the time t by Expressions (40) and (41).

  In step S12, one of the objects A and B for which the parameters after regrouping in step S11 are calculated is selected. In the next step S13, it is determined whether or not the own vehicle is controlling the object A or B selected in step S4, or whether or not the own vehicle is overtaking the object A or B. . If it is either under control or overtaking, the process proceeds to step S14, and if not, the process proceeds to step S15.

  In step S14, parameters to be used instead are selected on the assumption that the horizontal width and X coordinate value after regrouping calculated in step S11 are not used. At this time, if the object A is selected in step S12, the object B is selected in step S12 without using the lateral width WAr (t) and the X coordinate value XAr (t) after the regrouping of the object A. In this case, the horizontal width WBr (t) and the X coordinate value XBr (t) after the regrouping of the object B are not used. After executing step S14, the process proceeds to step S16.

  In step S14, when the lateral width WA (t) of the object A calculated in step S7 does not satisfy the equation (24), the lateral width WA (t) and the X coordinate value XA (t) are set to other values. Use it as is, without replacing it with. Further, when the lateral width WA (t) satisfies the expression (24) and the coordinate values (XA (t), ZA (t)) satisfy the expression (42), the lateral width WA (t) is set. The previous horizontal width WA (t−1) is also used as the current horizontal width, and the estimated X coordinate value XA ′ (t) obtained in step S3 is replaced with the X coordinate value XA (t). It is used as a coordinate value. Alternatively, when the lateral width WA (t) satisfies the equation (24) but the coordinate values (XA (t), ZA (t)) do not satisfy the equation (42), the width WA (t) is calculated in step S7. The horizontal width WA (t) and the X coordinate value XA (t) are used as they are without being replaced with other values.

  Note that the width B WB (t) and the X coordinate value XB (t) or the width WB (t−1) are similarly determined for the object B in step S14 depending on which of the expressions (31) and (43) is satisfied. ) And the estimated X coordinate value XB ′ (t).

  On the other hand, in step S15, the regrouped horizontal width and X coordinate value calculated in step S11 are used. That is, for the object A, the lateral width WA (t) and the X coordinate value XA (t) calculated in step S7 are replaced with the lateral width WAr (t) and the X coordinate value XAr (t) calculated in step S11, respectively. Try to use it. For the object B, the lateral width WB (t) and the X coordinate value XB (t) calculated in step S7 are replaced with the lateral width WBr (t) and the X coordinate value XBr (t) calculated in step S11. To use each. After executing Step S15, the process proceeds to Step S16.

  In step S16, it is determined whether or not all objects have been selected in step S12. When all the objects, that is, both the objects A and B have been selected, the process proceeds to step S17. If there is an object that has not yet been selected, the process returns to step S12. In step S17, the preceding vehicle information is output to the vehicle control unit 4 as described above based on the detection results of the objects A and B. After step S17 is executed, the process returns to step S1 and the above processing is repeated.

  In step S4 described above, the detection points that are not located within the grouping range of any object are processed as described above as detection points representing a new object. Thereby, each parameter is calculated also about a new object like other objects.

According to the embodiment described above, the following operational effects can be obtained.
(1) For the objects A and B ahead of the host vehicle, position coordinates (Xω (t), Zω (t)) indicating relative positions with respect to the host vehicle are detected at each detection point (step S1), and a predetermined condition is satisfied. By grouping the detection points and creating a group of detection points for each object, grouping is performed (step S4). Among detection points that are not included in this group, detection points that satisfy a predetermined regrouping condition are grouped for each object to create a group by regrouping. Thus, based on the position coordinates of the detection points grouped by the previous grouping and the detection points grouped by the regrouping, the X coordinate value XAr (after regrouping) indicating the relative positions of the objects A and B, respectively. t) and XBr (t) were calculated (step S11). Because of this, even if the detection points from the same object that should be grouped into the same group as originally representing one object are not correctly grouped, the positional relationship with each object is accurately determined. Can be sought.

(2) A predetermined regrouping range corresponding to each of the objects is set (step S8), and detection points included in the regrouping range are grouped for each regrouping range to create a group of detection points. And decided to regroup. Since it did in this way, the detection point which was not correctly grouped by the previous grouping can be put together into an appropriate group for every object by re-grouping.

(3) Calculation based on the width of the object calculated based on the relative position of each detection point grouped by the previous grouping, and the relative position of each detection point grouped by the previous grouping and regrouping The size of the regrouping range is changed based on the width of the object. Specifically, for the object A, when the difference between the average width WAλ obtained in the past and the currently obtained width WA (t) is larger than a predetermined threshold value Wt1, When the difference between the horizontal width average value WBλ obtained in the past and the horizontal width WB (t) obtained this time is larger than a predetermined threshold value Wt1, the regrouping range is set to be large as T1 = α. When these differences are smaller than the threshold value Wt1, the regrouping range is set to be small by setting T1 = β. If you think that there is a high possibility that there is a detection point that was not grouped correctly in the previous grouping, set a wide range so that the detection point can be regrouped. Can be set to a narrow range so as to prevent other detection points from being regrouped by mistake. As a result, it is possible to prevent one vehicle from being mistakenly detected as a plurality of objects, and vehicles running in parallel to be mistakenly detected as one object.

(4) One of the detection points included in the re-grouping range is selected by a different selection method according to the size of the re-grouping range (step S10), and only the selected detection point corresponds to the re-grouping range. It was included in the group of objects. Specifically, when the regrouping range is set to be large, the difference between the relative speed VA (t) of the object A calculated based on the result of the previous grouping and the relative speed Vω (t) is predetermined. Only the detection points that are equal to or less than the threshold value Vt1 are selected as detection points that are moving in the same direction as the movement direction of the corresponding object among the detection points included in the re-grouping range. When the regrouping range is set to be small, all the regrouping candidate detection points included in the regrouping range are selected. Since it did in this way, according to the magnitude | size of the set regrouping range, the detection point which actually regroups from the regrouping candidate detection points can be selected appropriately.

(5) The shape of the regrouping range is set so as to decrease stepwise as the distance from the center increases. Specifically, with respect to the re-grouping range, the central part of the lateral range corresponding to the vehicle width range of the other vehicle, and the part between the central part and the end part that is outside the central part of the lateral range center part And the left and right end portions on the outer side are set. Then, the length in the front direction and the rear direction is set to a predetermined value γ for the central portion of the horizontal range, and the length in the front direction and the rear direction is set to γ for the portion between the center portion and the end portion. The predetermined values δ and ε are set to be small, and the front and rear lengths are set to the left and right ends by a predetermined value ζ smaller than them. As described above, when a plurality of detection points having different distances from the host vehicle are detected by reflection from a place other than the back of the vehicle, the detection points are included in the regrouping range in the central portion of the horizontal range. Can be. In addition, in the portion between the center portion and the end portion, when a measurement error occurs in the distance of the detection point due to reflection from the vicinity of the vehicle end, the detection point can be included in the regrouping range. Furthermore, it is possible to prevent detection points from the vehicles in the adjacent lanes from being mistakenly included in the regrouping range at the outermost left and right ends.

(6) Furthermore, for the part between the center and the end, the length in the front direction of the regrouping range is set longer than the length in the rear direction. Since it did in this way, it can prevent re-grouping the detection point from the vehicle of the adjacent lane which appears from the near side rather than the detected vehicle accidentally.

(7) When it is determined whether the vehicle control means 4 is controlling the traveling of the host vehicle or the host vehicle is performing an overtaking operation (step S13), and it is determined that the traveling control is in progress or overtaking Are prohibited from using the re-grouped X coordinate value XAr (t) obtained for the object A and the re-grouped X coordinate value XBr (t) obtained for the object B, respectively. The X coordinate values XA (t) and XB (t) of this time are obtained by other methods (step S14). Because of this, if the relative position calculation error caused by incorrect regrouping is considered to have a large impact on the control of the host vehicle, this time without using the regrouping relative position. Can be obtained.

(8) When obtaining the current relative position without using the position coordinates after regrouping as described above,
(A) The difference between the average value WAλ of the past lateral width of the object A and the lateral width WA (t) obtained by the previous grouping is determined to be a predetermined threshold value. When the value is less than the value Wt1, the horizontal width WA (t) is set as the horizontal width of the current object, and the X coordinate value XA (t) obtained by the previous grouping is set as the current X coordinate value.
(B) The difference between the average value WAλ of the past lateral width of the object A and the lateral width WA (t) obtained by the previous grouping is determined to be a predetermined threshold value. If the value is equal to or greater than the value Wt1 and a part of the object A is out of the scan range of the laser radar 1, the lateral width WA (t) is set as the lateral width of the current object, and X by the previous grouping The coordinate value XA (t) is set as the current X coordinate value.
(C) The difference between the average value WAλ of the past lateral width of the object A and the lateral width WA (t) obtained by the previous grouping is determined to be a predetermined threshold value. If the value is equal to or greater than the value Wt1 and a part of the object A is within the scan range of the laser radar 1, the previous horizontal width WA (t−1) is set as the horizontal width of the current object and is obtained in the past. The estimated X coordinate value XA ′ (t) obtained based on the relative position of the object A is set as the current X coordinate value.
Since it did in this way, this time relative position can be calculated | required using a suitable value according to a condition.

  In the above-described embodiment, the example in which the relative position and the reflection intensity of each detection point are detected using the scanning laser radar has been described, but other examples may be used. For example, a radio wave radar may be used. Any object can be used as long as it can irradiate an object with an electromagnetic wave such as a laser beam or a radio wave, and detect the relative position to the vehicle and the reflection intensity of the electromagnetic wave at each detection point. .

  Further, in the above-described embodiment, an example in which the present invention is applied to an apparatus that detects an object existing in front of the host vehicle has been described. However, the present invention can also be applied to an apparatus that detects an object that exists in a direction other than the front, such as rearward or laterally, around the host vehicle.

  In the above embodiment, the example in which the relative position in the Z-axis direction of the object is determined based on the relative position (relative distance) in the Z-axis direction of one representative detection point has been described. However, not only the Z-axis direction but also the relative position in the X-axis direction may be determined based on the relative position of the representative detection point. Further, two or more representative detection points may be selected, and the relative position of the object may be determined based on the relative positions of the two or more representative detection points. Alternatively, the relative position of the object may not be determined by the relative position of the representative detection point. For example, the relative position of the object may be obtained by using an average value of the position coordinates of the grouped detection points.

  In the above embodiment, the position detecting means is realized by the laser radar 1, and the grouping means, the regrouping means, the position calculating means, the first and second object width calculating means, the regrouping detection point selecting means, and the overtaking determining means. The detection range determination unit and the position estimation unit are realized by the calculation unit 3, and the vehicle control unit is realized by the vehicle control unit 4. In the calculation unit 3, the position estimation unit is processed by the process of step S3 in FIG. 8, the grouping unit is processed by the process of step S4, the first and second object width calculation units are processed by the process of step S7, and the processes of steps S8 and S9. Thus, the regrouping means is realized, the regrouping detection point selecting means is realized by the process of step S10, the position calculating means is realized by the process of step S11, and the overtaking determining means is realized by the process of step S13. However, the configuration in the above embodiment including these is merely an example, and each component is not limited to the above embodiment unless the characteristics of the present invention are impaired. Other embodiments conceivable within the scope of the technical idea of the present invention are also included in the scope of the present invention.

It is a figure which shows the structure of the vehicle surrounding object detection apparatus by one Embodiment of this invention. It is the figure which showed the example of mounting to the own vehicle of a laser radar. It is a figure which shows a mode that the objects A and B ahead of the own vehicle which exist in the scanning range by a laser radar are detected. 4 is a diagram for explaining a grouping method performed on an object A. FIG. 4 is a diagram for explaining a grouping method performed on an object B. FIG. It is a figure which shows the example of the regrouping range each set about the object A and the object B, (a) shows the regrouping range of the object A, (b) shows the reblowing range of the object B. It is a figure for demonstrating that the influence which it has on control of the own vehicle will become large on the contrary when the estimated X coordinate value by the last calculation result is used when a part of object is outside the scanning range of the laser radar. . It is a flowchart which shows the process sequence of the object detection process performed in the vehicle surrounding object detection apparatus by one Embodiment of this invention.

Explanation of symbols

1: Laser radar 2: Vehicle behavior detection unit 3: Calculation unit 4: Vehicle control unit 11: Own vehicle 40, 50: Grouping range 41, 51: Re-grouping range

Claims (11)

Position detecting means for detecting a relative position with respect to the host vehicle at one or a plurality of detection points for an object around the host vehicle;
Grouping means for collecting detection points satisfying a predetermined grouping condition among detection points whose relative positions are detected by the position detection means, and creating a first group of detection points for each object;
Re-grouping means for collecting detection points satisfying a predetermined re-grouping condition among detection points not included in the first group created by the grouping means, and creating a second group of detection points for each object When,
And a position calculating means for obtaining a relative position of the object based on a relative position of each detection point grouped into the first and second groups by the grouping means and the regrouping means, respectively. Ambient object detection device. In the vehicle surrounding object detection device according to claim 1,
The re-grouping means sets a predetermined re-grouping range corresponding to each of the objects as the re-grouping condition,
The second group is created by grouping detection points included in the regrouping range among the detection points not included in the first group for each regrouping range. Ambient object detection device. In the vehicle surrounding object detection device according to claim 2,
First object width calculating means for calculating a first width as the width of the object based on the relative positions of the detection points collected in the first group;
A second object width calculating unit that calculates a second width as the width of the object based on the relative positions of the detection points respectively grouped into the first and second groups;
The vehicle surrounding object detection device, wherein the re-grouping means changes a size of the re-grouping range based on the first width and the second width. In the vehicle surrounding object detection device according to claim 3,
The regrouping means includes
A difference between an average value of past second widths calculated in the past by the second object width calculating unit and a current first width calculated by the first object width calculating unit is a predetermined value. If it is greater than or equal to the threshold value, set the re-grouping range larger,
The vehicle surrounding object detection device, wherein when the difference between the average value of the past second width and the current first width is less than a predetermined threshold, the re-grouping range is set small. In the vehicle surrounding object detection device according to claim 3 or 4,
Re-grouping detection point selection means for selecting any of the detection points included in the re-grouping range by a different selection method according to the size of the re-grouping range,
The re-grouping means collects the detection points selected by the re-grouping detection point selection means among the detection points included in the re-grouping range, and creates the second group. Object detection device. In the vehicle surrounding object detection device according to claim 5,
The re-grouping detection point selection means, when the re-grouping range is set large by the re-grouping means, the movement of the object corresponding to the re-grouping range among the detection points included in the re-grouping range Select only detection points that are moving in the same direction as
When the re-grouping means sets the re-grouping range to be small, all the detection points included in the re-grouping range are selected. In the vehicle surrounding object detection device according to any one of claims 2 to 6,
The vehicle surrounding object detection apparatus, wherein the re-grouping means sets the shape of the re-grouping range so that the re-grouping means decreases stepwise as the distance from the center increases. In the vehicle surrounding object detection device according to claim 7,
The regrouping means includes a first range with respect to the regrouping range, a second range outside the first range with respect to the center, and the center with respect to the second range. And a third range outside the vehicle is set. The vehicle surrounding object detection device according to claim 8,
For the second range, the vehicle surrounding object detection device is characterized in that the length in the front direction of the re-grouping range is set longer than the length in the rear direction. In the vehicle surrounding object detection device according to any one of claims 1 to 9,
Vehicle control means for controlling travel of the own vehicle based on the relative position of the object obtained by the position calculating means, or overtaking judgment means for judging whether or not the own vehicle is overtaking the object And further comprising at least one of
The position calculating means controls the first and second when the vehicle control means controls the traveling of the host vehicle or when the overtaking determination means determines that the vehicle is overtaking. An apparatus for detecting an object around a vehicle, which prohibits obtaining a relative position of the object based on a relative position of each detection point grouped in a group. In the vehicle surrounding object detection device according to any one of claims 3 to 6,
Vehicle control means for controlling travel of the own vehicle based on the relative position of the object obtained by the position calculating means, or overtaking judgment means for judging whether or not the own vehicle is overtaking the object And at least one of
Detection range determination means for determining whether a part of the object is out of the detection target range of the position detection means;
Position estimation means for obtaining a current estimated relative position of the object based on the relative position of the object obtained in the past by the position calculation means;
The position calculating means includes
(1) The case where the vehicle control means controls the traveling of the own vehicle, or the case where the overtaking judgment means judges that the vehicle is overtaking, and the second object width calculation means When the difference between the average value of the past second widths calculated in the past and the current first width calculated by the first object width calculation unit is less than a predetermined threshold value ,
The first width of the current time is set as the width of the object, and the relative position of the object is obtained based on the relative position of each detection point grouped into the first group by the grouping unit,
(2) The case where the vehicle control means controls the traveling of the own vehicle, or the case where the overtaking judgment means judges that the vehicle is overtaking, and the past second width When the difference between the average value and the current first width is equal to or greater than a predetermined threshold value, it is further determined by the detection range determination means that a part of the object is out of the detection target range. If
The first width of the current time is set as the width of the object, and the relative position of the object is obtained based on the relative position of each detection point grouped into the first group by the grouping unit,
(3) The case where the vehicle control means controls the traveling of the own vehicle, or the case where the overtaking judgment means judges that the vehicle is overtaking, and the past second width The difference between the average value and the current first width is equal to or greater than a predetermined threshold value, and it is further determined by the detection range determination means that a part of the object is not out of the detection target range. If
The previous second width calculated by the second object width calculating unit last time is set as the width of the object, and the estimated relative position calculated by the position estimating unit is set as the relative position of the object. A vehicle surrounding object detection device.

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