JP3923200B2 - Vehicle obstacle detection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a vehicle obstacle detection method for determining whether or not a detected object is the same obstacle by using a combination of a millimeter wave radar device and a laser radar device.
[0002]
[Prior art]
  A vehicle traveling safety device that detects an obstacle such as a preceding vehicle with a radar device mounted on its own vehicle and avoids contact by performing automatic braking when the vehicle may contact the obstacle is known. is there. As a radar device used in such a travel safety device, a millimeter wave radar device (see, for example, Japanese Patent Application Laid-Open Nos. 8-94749 and 7-318635) and a laser radar device are known.
[0003]
  Although the millimeter wave radar device can detect an obstacle without being influenced by weather conditions such as dense fog, there is a problem that the resolution in the horizontal direction is inferior because it is difficult to narrow down the beam. On the other hand, the laser radar device is excellent in the resolution in the left-right direction because the beam can be narrowed down, but may not be detected due to weather conditions such as dense fog.
[0004]
[Problems to be solved by the invention]
  By the way, since the laser radar device detects the reflector provided at the rear part of the preceding vehicle that is an obstacle, the laser radar device may misrecognize as two motorcycles running in parallel with a pair of left and right reflectors provided on the four-wheeled vehicle. There is a possibility that two reflectors respectively provided in two motorcycles running in parallel are mistakenly recognized as one automobile. Further, since the laser radar device detects an object that reflects light, there is a possibility of detecting a cat's eye or the like provided on the road as an obstacle.
[0005]
  On the other hand, the millimeter-wave radar device detects the entire body of the preceding vehicle, so that one preceding vehicle is mistakenly recognized as multiple preceding vehicles, or multiple preceding vehicles are regarded as one preceding vehicle. However, the millimeter-wave radar device has a problem that the horizontal resolution is insufficient as described above, and the horizontal width of the obstacle cannot be detected with high accuracy.
[0006]
  As described above, millimeter-wave radar devices and laser radar devices have advantages and disadvantages, but if both radar devices are used in an appropriate combination, both of the disadvantages are compensated for and the same object is detected. It is possible to accurately determine whether or not it is an object.
[0007]
  The present invention has been made in view of the above circumstances, and by using an appropriate combination of a millimeter wave radar device and a laser radar device, it is possible to accurately determine whether or not the detected object is the same obstacle. For the purpose.
[0008]
[Means for Solving the Problems]
  In order to achieve the above object, the invention described in claim 1 is a millimeter wave radar device that detects an obstacle by receiving a reflected millimeter wave transmitted forward in the traveling direction of the host vehicle; It is equipped with a laser radar device that detects obstacles by receiving the reflected wave of the laser beam transmitted forward in the traveling direction of the host vehicle,The obstacle detected by the millimeter wave radar device and the obstacle detected by the laser radar device within the determination region set around the obstacle are determined to be the same obstacle.A vehicle obstacle detection device that expands the determination region as the reflected wave reception intensity of a millimeter wave radar device increases.It is characterized by that.
[0009]
  According to the above configuration, while using both the millimeter wave radar device and the laser radar device to increase the obstacle detection capability, the laser radar device detects within the judgment area set around the obstacle detected by the millimeter wave radar device. It is possible to accurately determine whether or not the obstacles detected by both radar devices are the same object based on whether or not the obstacles exist.. AlsoSince the size of the obstacle is large, the determination area is expanded when the reception intensity of the reflected wave of the millimeter wave radar apparatus is strong. Therefore, it is possible to set the determination area according to the size of the obstacle and improve the determination accuracy.
[0010]
  And claims2The invention described in claim 11In addition to the configuration, when a plurality of obstacles are detected by the millimeter wave radar device, the size of the determination region is changed according to the distance between the plurality of obstacles.
[0011]
  According to the above configuration, since the size of the determination region is changed according to the distance between the plurality of obstacles detected by the millimeter wave radar device, a plurality of determination regions interfere with each other and erroneous determination occurs. Can be prevented.
[0012]
  And claims3The invention described in claim 11In addition to the above configuration, when a plurality of obstacles are detected by the millimeter wave radar device, a judgment area is set for each obstacle, and the judgment areas of adjacent obstacles overlap each other. The area is reduced.
[0013]
  According to the above configuration, when a plurality of obstacles are detected by the millimeter wave radar device, the determination areas corresponding to the obstacles are reduced so that the determination areas do not overlap with each other. It is possible to prevent erroneous determination from occurring due to overlapping.
[0014]
  And claims4The invention described in claim 13In addition to the above-described configuration, the reduction ratio is smaller for a determination region having a smaller distance from the host vehicle or for a determination region existing in front of the host vehicle.
[0015]
  According to the above configuration, when the determination areas of a plurality of obstacles overlap with each other, the determination area having a smaller distance from the own vehicle or the determination area existing in front of the own vehicle is set to be larger. If the obstacle detected by both radar devices is unlikely to be another object because the vehicle is near or in front of the vehicle, the obstacle detected by both radar devices is erroneously determined to be another object. Can be prevented.
[0016]
  And claims5The invention described in claim 11In addition to the above configuration, when obstacles previously detected by the millimeter wave radar device and laser radar device are continuously detected, the detection result of the previous millimeter wave radar device and the detection result of the previous laser radar device The determination area is set according to a distance relationship.
[0017]
  According to the above configuration, when the previously detected obstacle is continuously detected, the determination region according to the distance relationship between the detection result of the previous millimeter wave radar device and the detection result of the previous laser radar device. Therefore, the determination area can be set more appropriately by effectively using the highly accurate detection result of the obstacle that is continuously detected.
[0018]
  And claims6The invention described in claim 11In addition to the above-described configuration, the determination region is determined according to the relative velocity of the obstacle calculated based on the detection result of the millimeter wave radar device or the laser radar device and the difference in detection time of the millimeter wave radar device and the laser radar device. The size ofExpansionIt is characterized by doing.
[0019]
  According to the above configuration, the size of the determination area is set according to the relative speed of the vehicle and the obstacle and the difference between the detection times of the two radar devices.ExpansionTherefore, even if there is a deviation between the detection result of the radar device detected earlier due to the relative speed and the current situation, the deviation can be compensated and a correct determination can be made..
[0020]
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below based on the embodiments of the present invention shown in the accompanying drawings.
[0021]
  1 to 151 shows an embodiment of the present invention, FIG. 1 is an overall configuration diagram of a vehicle equipped with an obstacle detection device, FIG. 2 is a block diagram of a braking system, and FIG. 3 is an explanatory diagram of an obstacle detection operation of a laser radar device. 4 is an explanatory diagram of the obstacle detection operation of the millimeter wave radar device, FIG. 5 is an explanatory diagram of a method for identifying the left and right relative positions of the obstacles from the received intensity of each beam of the millimeter wave radar device, and FIG. FIG. 7 is a flowchart for explaining the operation, FIG. 8 is a diagram for explaining how to set and determine the judgment area, and FIG. 9 is a reception by the millimeter wave radar device. FIG. 10 is an explanatory diagram of determination area setting when two obstacles are approaching, and FIG. 11 is an explanatory diagram of determination area setting when two obstacles are approaching. Figure 12 shows FIG. 13 is an explanatory diagram of determination area setting based on previous detection data, and FIG. 14 is an erroneous determination caused by the difference between the relative speed of the obstacle and the detection timing of both radar devices. FIG. 15 is an explanatory diagram of determination area correction considering the difference between the relative speed of the obstacle and the detection timing of both radar devices.sois there.
[0022]
  As shown in FIGS. 1 and 2, a four-wheeled vehicle V equipped with the obstacle detection device of the present invention has left and right front wheels W as driving wheels to which driving force of an engine E is transmitted via a transmission T._FL, W_FRLeft and right rear wheels W as driven wheels that rotate as the vehicle V travels_RL, W_RRWith. A brake pedal 1 operated by a driver is connected to a master cylinder 3 via an electronically controlled negative pressure booster 2. The electronically controlled negative pressure booster 2 mechanically boosts the depressing force of the brake pedal 1 to operate the master cylinder 3, and at the time of braking assistance, the braking command signal from the electronic control unit U does not depend on the operation of the brake pedal 1. Thus, the master cylinder 3 is operated. When a pedaling force is input to the brake pedal 1 and a braking command signal is input from the electronic control unit U, the electronically controlled negative pressure booster 2 outputs the brake hydraulic pressure in accordance with whichever is larger. The input rod of the electronically controlled negative pressure booster 2 is connected to the brake pedal 1 through a lost motion mechanism, and the electronically controlled negative pressure booster 2 is actuated by a signal from the electronic control unit U so that the input rod is moved forward. The brake pedal 1 remains in the initial position even when moved to.
[0023]
  The pair of output ports 8 and 9 of the master cylinder 3 are connected to the front wheels W via the hydraulic control device 4._FL, W_FRAnd rear wheel W_RL, W_RRBrake caliper 5_FL, 5_FR, 5_RL, 5_RRConnected to. The hydraulic control device 4 has four brake calipers 5_FL, 5_FR, 5_RL, 5_RRCorresponding to the four pressure regulators 6... Are connected to the electronic control unit U, and each of the pressure regulators 6._FL, W_FRAnd rear wheel W_RL, W_RRBrake caliper 5_FL, 5_FR, 5_RL, 5_RRThe operation of each is controlled individually. Accordingly, each brake caliper 5 is controlled by the pressure regulator 6._FL, 5_FR, 5_RL, 5_RRIf the brake hydraulic pressure transmitted to the vehicle is controlled independently, anti-lock brake control for suppressing the lock of the wheel during braking can be performed.
[0024]
  A millimeter wave is transmitted to the electronic control unit U toward the front of the vehicle body, and the front-rear relative position, the left-right relative position and the relative speed between the obstacle such as the preceding vehicle and the own vehicle are detected based on the reflected wave. Wave radar device S₁And a laser radar device that detects a front-rear relative position and a left-right relative position of an obstacle such as a preceding vehicle and the own vehicle, and a left-right width of the obstacle based on the reflected wave. S₂And are connected. Furthermore, the electronic control unit U has a front wheel W_FL, W_FRAnd rear wheel W_RL, W_RRWheel speed sensor S for detecting the rotational speed of each_Three... are connected.
[0025]
  Thus, the electronic control unit U is connected to the millimeter wave radar device S.₁And laser radar device S₂Based on the detection results, the front-rear relative position, the left-right relative position, the relative speed, and the left-right width of the obstacle such as the preceding vehicle based on the own vehicle are calculated. Left and right width and wheel speed sensor S_ThreeThe possibility of contact with an obstacle is determined based on the speed and acceleration of the vehicle detected in. When there is a possibility that the vehicle will come into contact with an obstacle, the electronically controlled negative pressure booster 2 is actuated by a command from the electronic control unit U, and the brake hydraulic pressure generated by the master cylinder 3 is adjusted by the hydraulic control device 4. Pressed brake caliper 5_FL, 5_FR, 5_RL, 5_RRThe automatic braking is executed to avoid contact with the obstacle.
[0026]
  Millimeter wave radar system S₁And laser radar device S₂Have different detection characteristics, and using the difference between the detection characteristics, it is determined whether or not the detected objects are the same obstacle. Details will be described below.
[0027]
  First, millimeter wave radar device S₁And laser radar device S₂The detection characteristics will be described.
[0028]
  Laser radar device S₂Since the laser used in the laser can narrow the beam narrowly, as shown in FIG. 3, the narrow beam transmitted to the front of the vehicle body is scanned from the obstacle while scanning in the left-right direction (or left-right direction and up-down direction). By receiving the reflected wave, the front and rear relative positions of the obstacle are detected based on the time from the transmission to the reception, and the right and left relative positions of the obstacle are determined based on the transmission direction of the beam when the reflected wave is received. Detect position.
[0029]
  Laser radar device S₂Is superior in the horizontal resolution. As shown in FIG. 6, when the obstacle is a front vehicle, the left and right reflectors provided on the rear surface of the vehicle body are mainly detected. The position and left / right width detection accuracy is very good. On the other hand, it is possible to misrecognize two motorcycles running side by side on the left and right reflectors of one four-wheeled vehicle, or to misrecognize two motorcycles running side-by-side as one four-wheeled vehicle. There is sex.
[0030]
  On the other hand, millimeter wave radar device S₁Since the millimeter wave used in is difficult to narrow down compared with a laser, as shown in FIG. 4, by transmitting a plurality of millimeter wave beams radially in front of the vehicle body and receiving reflected waves, Detecting the front and rear relative positions of the obstacle based on the time from transmission to reception, and detecting the right and left relative positions of the obstacle based on the transmission direction of the beam from which the reflected wave was received among the plurality of beams, Furthermore, the relative speed of the obstacle is detected based on the Doppler principle. At this time, since reflected waves of a plurality of beams are received with respect to one obstacle, as shown in FIG. 4 and FIG. 5, the centroid position of the reception intensity of the plurality of beams is calculated, and the centroid position is calculated. Estimated as the left-right relative position of the obstacle. For the above reasons, millimeter wave radar device S₁The horizontal resolution of the laser radar device S₂Lower than that.
[0031]
  As described above, the millimeter wave radar device S₁Can be used regardless of the weather, but there is a problem that the resolution in the horizontal direction is low.₂Has a problem that it can not be used depending on the weather, although the resolution in the horizontal direction is high. So both radar devices S₁, S₂It is conceivable to perform highly accurate detection without being influenced by the weather, but in this case, the millimeter wave radar device S₁Detected obstacles and laser radar device S₂It is necessary to determine whether or not the obstacle detected in step 1 is the same.
[0032]
  Next, a procedure for determining whether or not the detected object is the same obstacle will be described with reference to the flowchart of FIG.
[0033]
  First, in step S1, the millimeter wave radar device S₁Based on the detection result, the relative position of the obstacle ahead is detected as a reference. As is apparent from FIG. 6, the detected relative position is given by coordinate data Mi (xmi, ymi). This xy coordinate system is fixed to the host vehicle, the x-axis extends forward of the vehicle body, and the y-axis extends perpendicularly to the x-axis and to the left of the vehicle body. Millimeter wave radar system S₁Since the detection result by is given by the barycentric position of the reception intensity of a plurality of beams, the coordinate data Mi (xmi, ymi) of the relative position is one for one obstacle.
[0034]
  In the following step S2, the laser radar device S₂Based on the detection result, the relative position of the obstacle ahead is detected as a reference. As is apparent from FIG. 6, the detected relative position is given by coordinate data Rj (xrj, yrj) in the xy coordinate system. Laser radar device S₂Detects the left and right reflectors provided at the rear of the obstacle, so the relative position coordinate data Rj (xrj, yrj) is normally two for one obstacle.
[0035]
  In the following step S3, the millimeter wave radar device S₁The determination area Ai is set on the basis of the coordinate data Mi (xmi, ymi) of the relative position of the obstacle detected in step. This determination area Ai is a millimeter wave radar device S.₁Centered on the coordinate data Mi (xmi, ymi) of the relative position of the obstacle detected in step 1, each having a width a (for example, a = 2 m) in the front-rear direction and a distance b (for example, b in the left-right direction). = 2m), the range is a square (see FIG. 8). That is, the determination area Ai is
          Ai; (xmi−a ≦ x ≦ xmi + a)
                          And (ymi−b ≦ y ≦ ymi + b)
It is represented by The distances a and b are the millimeter wave radar device S.₁And laser radar device S₂It is set according to the detection accuracy.
[0036]
  In the following step S4, the laser radar device S₂It is determined whether or not the coordinate data Rj (xrj, yrj) of the relative position of the obstacle detected in step 3 exists in the determination region Ai. If the coordinate data Rj exists in the determination region Ai, in step S5 , Laser radar device S₂Obstacle "Rj" detected by the millimeter wave radar device S₁It is determined that the obstacle is the same object as the obstacle “Mi” detected in. On the other hand, if the coordinate data Rj does not exist inside the determination area Ai, in step S6, the laser radar device S₂Obstacle "Rj" detected by the millimeter wave radar device S₁It is possible to determine that the obstacle is not the same object as the obstacle “Mi” detected in.
[0037]
  Specifically, in FIG. 6, the obstacle on the side close to the own vehicle has a millimeter wave radar device S.₁In the determination area A1 set with reference to the coordinate data M1 (xm1, ym1) of the relative position detected by the laser radar device S₂The coordinate data R1 (xr1, yr1) and R2 (xr2, yr2) of the relative positions of the two reflectors detected in FIG.₁Detected obstacles and laser radar device S₂It is determined that the obstacle detected in step 1 is the same object. Similarly, in the obstacle on the side far from the own vehicle in FIG.₁In the determination area A2 set with reference to the coordinate data M2 (xm2, ym2) of the relative position detected by the laser radar device S₂The coordinate data R3 (xr3, yr3) and R4 (xr4, yr4) of the relative positions of the two reflectors detected in step S3 exist, and therefore the millimeter wave radar device S₁Detected obstacles and laser radar device S₂It is determined that the obstacle detected in step 1 is the same object.
[0038]
  In order to increase the accuracy of the determination, the size and shape of the determination area Ai are corrected by the methods (1) to (4) described below.
(1)Correction by reception intensity of millimeter wave radar equipment
  Millimeter wave radar system S₁The reception intensity is strong when the obstacle is a large vehicle such as a truck, and is weak when the obstacle is a small vehicle such as a motorcycle. That is, it is estimated that an obstacle with strong reception strength has a large lateral width, and an obstacle with weak reception strength has a small lateral width. Therefore, as shown in FIG.₁As the received intensity increases, the distance b in the y-axis direction is corrected in the increasing direction, thereby correcting the left-right width of the determination area Ai in the increasing direction.
[0039]
  In addition, millimeter wave radar device S₁As the received intensity, the maximum value among the received intensity of a plurality of beams is adopted. The distance a in the x-axis direction is similarly set to the millimeter wave radar device S.₁It may be corrected in the increasing direction according to the received intensity.
(2)Correction when multiple judgment areas overlap
  As is clear from FIG. 10, the millimeter wave radar device S₁When the two coordinate data Mi and Mj are detected, the determination areas Ai and Aj corresponding to the coordinate data Mi and Mj are respectively
          Ai; (xmi−ai ≦ x ≦ xmi + ai)
                          And (ymi−bi ≦ y ≦ ymi + bi)
          Aj; (xmj−aj ≦ x ≦ xmj + aj)
                          And (ymj−bj ≦ y ≦ ymj + bj)
It is represented by
[0040]
  The distance dxij in the x-axis direction and the distance dyij in the y-axis direction of the two coordinate data Mi and Mj are respectively
                  dxij = | xmi−xmj |
                  dyij = | ymi-ymj |
Given in. At this time, the two coordinate data Mi and Mj are approaching,
          dxij ≦ ai + aj and dyij ≦ bi + bj
As shown in FIG. 10, a part of the two determination areas Ai and Aj overlap each other as shown in FIG.
[0041]
  In such a case, as shown by a broken line in FIG. 10, the two determination areas Ai and Aj are divided so as not to overlap to prevent the occurrence of erroneous detection. As another method, as shown in FIG. 11, the two determination areas Ai and Aj can be divided by a straight line parallel to the x-axis. At this time, the reduction amount p of the determination area Ai closer to the front of the host vehicle is reduced, and the reduction amount q of the determination area Aj farther from the front of the host vehicle is increased. As another method, the reduction amount p of the determination area Ai on the side where the front-rear relative distance from the own vehicle is small is reduced, and the reduction amount q of the determination area Aj on the side where the front-rear relative distance from the own vehicle is large is increased. As a result, both radar devices S₁, S₂When the obstacle detected in (1) is present in front of the host vehicle or in the vicinity of the host vehicle and is likely to be the same object, it can be prevented that it is erroneously determined as another object. As a simple method, the reduction amounts p and q of the two determination areas Ai and Aj may be made equal (p = q).
(3)Correction using previous detection data
  Here, the width of the determination area Ai in the y-axis direction is corrected using the previous detection data. As shown in FIG. 12, a plurality of coordinate data close to each other, that is, the millimeter wave radar device S₁And coordinate data M1 detected by the laser radar device S₂The two coordinate data R1 and R2 detected by the above constitute one obstacle, and the width W of the obstacle is the coordinates located at the left and right ends of the three coordinate data M1, R1 and R2. It is given by the distance between the data R1 and R2. This millimeter-wave radar device S₁The obstacle width W obtained from the previous coordinate data M1, R1, R2 is equally distributed to the left and right with the coordinate data M1 at the center as the center, and a predetermined distance c is added to the left and right outside of the determination area. Sets the width of Ai in the y-axis direction. Further, the width of the determination region Ai in the x-axis direction is the same as that of the current millimeter-wave radar device S.₁It is assumed that the distance a is added in the front-rear direction around the coordinate data M1. That is, the determination area Ai is defined as follows. The distance c is the millimeter wave radar device S.₁And laser radar device S₂It is set according to the detection accuracy.
[0042]
          Ai; (xmi−a ≦ x ≦ xmi + a)
                And (ymi−W / 2−c ≦ y ≦ ymi + W / 2 + c)
  FIG. 13 explains another method, and the laser radar device S corresponding to one obstacle.₂This is applied when the coordinate data R1 to R4 are distributed in the x-axis direction and the y-axis direction. If, for example, five coordinate data M1, R1 to R4 constitute one obstacle in the previous detection result, the millimeter wave radar device S₁The laser radar device S that is farthest in the positive direction of the x-axis with reference to the coordinate data M1₂The distance to the coordinate data R4 is dx (+), and similarly, the laser radar device S farthest away in the negative direction of the x-axis₂The distance to the coordinate data R1, R2 is dx (-), and the laser radar device S that is farthest in the positive direction of the y-axis₂The distance to the coordinate data R2 and R3 is dy (+), and the laser radar device S that is farthest in the negative direction of the y-axis₂The distance to the coordinate data R1 is dy (−).
[0043]
  Thus, the determination area Ai is defined as follows using the distances dx (+), dx (−), dy (+), dy (−) and a preset distance c.
[0044]
  Ai; (xmi−dx (−) − c ≦ x ≦ xmi + dx (+) + c)
            And (ymi−dy (−) − c ≦ y ≦ ymi + dy (+) + c)
  This determination area Ai is the previous millimeter-wave radar device S.₁Based on the coordinate data M1 obtained by detection of the previous laser radar device S₂The distances dx (+), dx (−), dy (+), dy (−), which are the maximum deviations in the x-axis direction and the y-axis direction of the coordinate data R1 to R4 obtained by the detection of the A value obtained by adding a preset distance c to dx (+), dx (−), dy (+), dy (−) is used as the current millimeter-wave radar device S.₁This is equivalent to the data distributed in the x-axis direction and the y-axis direction with reference to the coordinate data M1 obtained by the detection.
[0045]
  As described above, the millimeter wave radar device S₁And laser radar device S₂By setting the determination area Ai using the previous detection result and the current detection result for the obstacle that is continuously detected by the laser radar device S₂Obstacles detected in the millimeter wave radar device S₁It is possible to more accurately determine whether or not the obstacle is the same as the obstacle detected in.
(Four) Correction to compensate for the detection time difference between both radar devices
  Millimeter wave radar system S₁And laser radar device S₂Are detecting each with a fixed period and asynchronously, and the determination of the identity of the detected obstacle is performed by the millimeter wave radar device S.₁It is executed with reference to the detection cycle. In this case, the millimeter wave radar device S₁Detection timing and laser radar device S₂The laser radar device S₂Detection data of millimeter wave radar device S₁It is earlier than the detected data. Both radar devices S₁, S₂When both detection periods are 100 msec, the time difference between the detection timings is 100 msec at the maximum.
[0046]
  In such a case, there is no particular problem if there is no relative speed between the own vehicle and the obstacle, but an erroneous determination occurs if there is a relative speed between the own vehicle and the obstacle. The reason for this will be described with reference to FIG.₁The detection area Ai is set based on the coordinate data M1 detected by the laser radar device S in the detection area Ai.₂When it is determined whether or not the coordinate data R1, R2 detected in step S2 is included, if there is a relative speed between the vehicle and the obstacle, the laser radar device S with early detection timing₂The coordinate data R1 and R2 are shifted from the current position indicated by the solid line to the position indicated by the broken line at the time of determination. If the determination is performed using the shifted coordinate data R1 and R2 as they are, an erroneous determination is made. Will occur. In the example of FIG. 14, the laser radar device S is actually in the determination area Ai.₂Both radar devices S including the coordinate data R1, R2 detected in₁, S₂In order to use the coordinate data R1 and R2 whose detection timing is early, it is determined that the obstacle detected in step 2 is the same object.₁, S₂If the obstacle detected in step 1 is not the same object, it may be erroneously determined.
[0047]
  Therefore, as shown in FIG.₁The relative speed of the vehicle and obstacles detected by the₁, S₂The distance L is calculated by integrating the time difference of the detection timings (in the present embodiment, it is assumed that the maximum value is 100 msec), and the length of the determination area Ai in the x-axis direction is increased by this distance L.AdditionBy correcting so as to do, the occurrence of the erroneous determination can be avoided. The relative speed of the vehicle and the obstacle can be detected based on the Doppler principle, and can also be calculated based on the deviation of the previous front-rear relative position and the current front-rear relative position..
[0048]
  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.
[0049]
  For example, in this embodiment, the time difference of the detection timing is set to 100 msec which is the maximum value. However, in the case where the time difference of the actual detection timing is obtained, the time difference may be used. In this embodiment, the determination area Ai and the coordinate data R1, R2 are corrected in the x-axis direction. However, the determination area Ai and the coordinate data R1, R2 can also be corrected in the y-axis direction that is the left-right direction.
[0050]
【The invention's effect】
  As described above, according to the first aspect of the present invention, the millimeter wave radar device and the laser radar device are used together to increase the obstacle detection capability, and set around the obstacle detected by the millimeter wave radar device. It is possible to accurately determine whether or not the obstacle detected by both radar devices is the same object based on whether or not the obstacle detected by the laser radar device exists in the determined determination area.. AlsoSince the size of the obstacle is large, the determination area is expanded when the reception intensity of the reflected wave of the millimeter wave radar apparatus is strong. Therefore, it is possible to set the determination area according to the size of the obstacle and improve the determination accuracy.
[0051]
  And claims2According to the invention described in the above, since the size of the determination region is changed according to the distance between the plurality of obstacles detected by the millimeter wave radar device, the plurality of determination regions interfere with each other and erroneous determination is made. It can be prevented from occurring.
[0052]
  And claims3According to the invention described in the above, when a plurality of obstacles are detected by the millimeter wave radar device, the determination areas corresponding to the obstacles are reduced so that they do not overlap with each other. It is possible to prevent erroneous determination from occurring due to regions overlapping each other.
[0053]
  And claims4According to the invention described in the above, when the determination areas of a plurality of obstacles overlap with each other, the determination area having a smaller distance from the own vehicle or the determination area existing in front of the own vehicle is set larger. If the obstacle detected by both radar devices is unlikely to be another object because the obstacle is near or in front of the vehicle, the obstacle detected by both radar devices is a different object. It is possible to prevent erroneous determination.
[0054]
  And claims5According to the invention described in, according to the distance relationship between the detection result of the previous millimeter-wave radar device and the detection result of the previous laser radar device when the previously detected obstacle is continuously detected. Thus, the determination area can be set more appropriately by effectively using the highly accurate detection result of the obstacle that is continuously detected.
[0055]
  And claims6According to the invention described in the above, the size of the determination area is set according to the relative speed of the host vehicle and the obstacle and the difference between the detection times of the two radar devices.ExpansionTherefore, even if there is a deviation between the detection result of the radar device detected earlier due to the relative speed and the current situation, the deviation can be compensated and a correct determination can be made..
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a vehicle equipped with an obstacle detection device.
[Fig. 2] Block diagram of the braking system
FIG. 3 is an explanatory diagram of the obstacle detection action of the laser radar device.
FIG. 4 is an explanatory diagram of the obstacle detection effect of the millimeter wave radar device.
FIG. 5 is an explanatory diagram of a technique for identifying the left-right relative position of an obstacle from the reception intensity of each beam of a millimeter wave radar device.
FIG. 6 is an explanatory view of relative position detection of an obstacle by a millimeter wave radar device and a laser radar device.
FIG. 7 is a flowchart for explaining the operation.
FIG. 8 is an explanatory diagram of determination area setting and determination method
FIG. 9 is a map for searching for the correction distance from the reception intensity of the millimeter wave radar device.
FIG. 10 is an explanatory diagram of determination area setting when two obstacles are approaching each other.
FIG. 11 is an explanatory diagram of determination area setting when two obstacles are approaching each other.
FIG. 12 is an explanatory diagram of determination area setting based on previous detection data
FIG. 13 is an explanatory diagram of determination area setting based on previous detection data.
FIG. 14 is an explanatory diagram of misjudgment caused by the difference between the relative speed of an obstacle and the detection timing of both radar devices.
FIG. 15 illustrates determination area correction in consideration of the relative speed of an obstacle and the difference in detection timing of both radar devices.Figure
[Explanation of symbols]
Ai, Aj judgment area
S₁        Millimeter wave radar device
S₂        Laser radar device
V vehicle (own vehicle)

Claims (6)

A millimeter wave radar device (S ₁ ) that detects an obstacle by receiving a reflected wave of the millimeter wave transmitted forward in the traveling direction of the host vehicle (V);
A laser radar device (S ₂ ) that detects an obstacle by receiving a reflected wave of a laser beam transmitted forward in the traveling direction of the host vehicle (V) ;
The obstacle detected by the millimeter wave radar device (S ₁ ) is identical to the obstacle detected by the laser radar device (S ₂ ) in the determination area (Ai, Aj) set around the obstacle. An obstacle detection method for a vehicle that is determined to be an obstacle,
Characterized that, in vehicles obstacle detection method that the reception intensity of the reflected wave of the millimeter-wave radar apparatus (S ₁₎ to expand the strong that the determination area (Ai, Aj). When a plurality of obstacles are detected by the millimeter wave radar device (S ₁ ), the size of the determination area (Ai, Aj) is changed according to the distance between the plurality of obstacles. The vehicle obstacle detection method according to claim 1 . When a plurality of obstacles are detected by the millimeter wave radar device (S ₁ ), determination areas (Ai, Aj) are set for the respective obstacles, and adjacent obstacle determination areas (Ai, Aj) There the determination area (Ai, Aj) when overlapping each other, characterized in that reducing the obstacle detection method for a vehicle according to claim 1. The reduction ratio is reduced as the determination area (Ai, Aj) having a smaller distance from the own vehicle (V) or as the determination area (Ai, Aj) existing in front of the own vehicle (V) is characterized. The vehicle obstacle detection method according to claim 3 . When an obstacle previously detected by the millimeter wave radar device (S ₁ ) and the laser radar device (S ₂ ) is continuously detected, the detection result of the previous millimeter wave radar device (S ₁ ) and the previous laser The obstacle detection method for a vehicle according to claim 1 , wherein the determination area (Ai, Aj) is set according to a distance relationship of detection results of the radar device (S ₂ ). Millimeter wave radar device (S ₁₎ or a laser radar device (S ₂₎ of detecting the relative velocity of the obstacle is calculated based on the results, detection time of the millimeter-wave radar apparatus (S ₁₎ and a laser radar device (S ₂₎ depending of the the difference, the determination region (Ai, Aj), characterized in that to enlarge the size of the obstacle detection method for a vehicle according to claim 1.

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