JP2009288097A - Object detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an object detector for detecting a stopped vehicle in distinction from a road marking or a road-placed object such as a reflective object embedded in a road surface. <P>SOLUTION: A radar device 1 scans horizontally and vertically with laser light to detect an object existing in front of an own vehicle. Further, a control part 2 is used for determining that the detected object is a road-placed object not hindering the traveling of the own vehicle when the following four conditions all hold good as to the detected object: (a) it is a stopped object; (b) the distance thereto from the own vehicle is shorter than a predetermined road-placed object determination distance D1; (c) the intensity of a reflected wave obtained by a preceding downward scan is larger than a road-placed object determination coefficient times (×α1) as large as the intensity of a reflected wave obtained by a preceding upward scan; and (d) the intensity of a reflected wave obtained by the preceding downward scan is larger than the intensity of a reflected wave obtained by a reference scan of this time. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an object detection device that uses an electromagnetic wave such as a laser beam or a radio wave as an exploration wave to detect an object positioned in front of a vehicle (own vehicle) to which the apparatus main body is attached.

  Conventionally, there has been a vehicle ranging device that scans an exploration wave irradiated in front of the host vehicle, detects a preceding vehicle located in front of the vehicle, and measures a distance to the detected preceding vehicle (for example, Patent Document 1). A vehicle ranging device uses electromagnetic waves such as laser light and radio waves as exploration waves. Using this vehicle distance measuring device, constant distance between vehicles (ACC: Adaptive Cruise Control) that keeps the distance from the preceding vehicle constant, and following (LSF: Low Speed Following) in traffic jams (low speed) are performed. It has been broken. There is also a pre-crash safety system that applies braking to reduce the damage caused by a collision when a preceding vehicle or a stop that is present at a distance where a collision cannot be avoided is detected in front of the host vehicle. If the preceding vehicle to be controlled by these controls is limited to the stopped vehicle that is running or stopped from the running state, the stopped vehicle that has already been stopped at the time of detection is excluded from the control target. Considering the case where a stopped vehicle that is not to be controlled is stopped on its own lane, a stopped vehicle that has already been stopped at the time of detection needs to be a control target. In order to detect a stopped vehicle that was stopped at the time of detection as a control target, the stopped vehicle is placed on a road surface installation such as a road marking or a reflective object (so-called cat's eye) embedded in the road surface, or on a pedestrian bridge or above. It must be detected separately from the installed objects such as installed signs.

  In addition, the road surface installation thing and upper installation thing said here are not an obstruction which prevents driving | running | working of the own vehicle.

Patent Document 2 proposes that the above-mentioned road surface installation object and the upper installation object be prevented from being erroneously detected as an obstacle such as a stopped vehicle. In this patent document 2, the scanning by the upper irradiation that irradiates the exploration wave upward and the scanning by the lower irradiation that irradiates the exploration wave downward are repeated for each detected object. The reflection intensity at the time of irradiation is compared to determine whether the object is a road surface installation object, an upward installation object, or an obstacle (stopped vehicle or the like). Specifically, if the absolute value of the difference between the reflection intensity at the time of upward irradiation and the reflection intensity at the time of downward irradiation is within a predetermined range, it is determined as an obstacle. In addition, if the absolute value of the difference between the reflection intensity at the time of the upper irradiation and the reflection intensity at the time of the lower irradiation is not within a predetermined range and the reflection intensity at the lower irradiation is larger than the reflection intensity at the upper irradiation, the road surface Judged as an installation. Furthermore, if the absolute value of the difference between the reflection intensity at the time of the upper irradiation and the reflection intensity at the time of the lower irradiation is not within the predetermined range and the reflection intensity at the upper irradiation is larger than the reflection intensity at the lower irradiation, Judged as an installation.
JP 2006-337295 A JP 2006-98220 A

  An object of the present invention is to provide an object detection device that can detect a stopped vehicle separately from road surface markings and road surface installations such as reflectors embedded in the road surface.

  Another object of the present invention is to provide an object detection device that can detect a stopped vehicle by distinguishing it from an upward installation such as a footbridge or a signboard installed above.

  The object detection device of the present invention is configured as follows in order to solve the above-mentioned problems and achieve the object.

  In this object detection apparatus, the irradiating means irradiates the exploration wave in front of the vehicle (own vehicle) to which the apparatus main body is attached, and the detecting means detects the reflected wave of the exploration wave. As the exploration wave, electromagnetic waves such as laser light and radio waves are used. The distance calculation means calculates the distance to the object that reflected the probe wave that was irradiated this time, based on the time from when the irradiation means irradiates the exploration wave until the detection means detects the reflected wave.

  Further, the irradiation direction switching unit switches the irradiation direction in the vertical direction of the exploration wave irradiated by the irradiation unit between a reference direction and a downward direction downward from the reference direction. Then, the object determination means is shorter in the downward direction than when the distance calculated by the distance calculation means is shorter than a predetermined road surface installation determination distance and the intensity of the reflected wave is irradiated in the reference direction. An object that is larger when it is irradiated is determined as a road surface installation object.

  The object detection device irradiates the exploration wave in the reference direction as well as when the exploration wave irradiates in the downward direction due to the divergence angle of the exploration wave in the vertical direction, the angle difference between the reference direction and the downward direction, the road gradient, etc. Even in this case, the reflected wave reflected by a road surface installation object such as a road marking or a reflection object embedded in the road surface may be detected. Usually, the intensity of the reflected wave from the road surface installation when the exploration wave is irradiated downward is increased to some extent as compared with the case where the exploration wave is irradiated in the reference direction.

  On the other hand, when approaching a stop vehicle with a short height, a stop vehicle with a low reflector installation position, etc., the reflection intensity at the time of downward irradiation is reflected at the time of downward irradiation at a position that is slightly away from the stop vehicle. May be considerably larger than strength. This is mainly due to the fact that the reflection of the laser beam at the reflector of the stopping vehicle ahead is larger during downward irradiation than during upward irradiation.

  As described above, the object determination means is shorter than the predetermined road surface installation determination distance calculated by the distance calculation means, and the intensity of the reflected wave is irradiated in the reference direction, Since the object that is larger when irradiated in the downward direction is determined as a road surface installation object, when the vehicle approaches a stop vehicle with a short height or a reflector with a low reflector installation position, It is possible to prevent erroneous determination as being.

Further, the irradiation direction switching means described above is replaced with a configuration in which the irradiation direction in the vertical direction of the exploration wave irradiated by the irradiation means is switched between a reference direction and an upward direction upward from the reference direction.
When the distance calculated by the distance calculation means is longer than the predetermined upper object determination distance, and the object determination means is more than when the reflected wave intensity is irradiated in the reference direction. Alternatively, an object that is larger when irradiated in the upward direction may be replaced with a configuration in which the object is determined as an upward installation object.

  The object detection device irradiates the exploration wave in the reference direction as well as when the exploration wave is radiated upward due to the divergence angle of the exploration wave in the vertical direction, the angle difference between the reference direction and the upward direction, the road gradient, etc. In some cases, a reflected wave reflected by an installation object such as a footbridge or a signboard installed above may be detected. Usually, the intensity of the reflected wave from the upper installation when the exploration wave is irradiated upward is increased to some extent as compared with the case where the exploration wave is irradiated in the reference direction.

  On the other hand, when the host vehicle approaches a relatively tall stopped vehicle such as a truck, the reflection intensity at the time of upward irradiation may be considerably larger than the reflection intensity at the time of downward irradiation. This is mainly due to the fact that the reflection of the laser beam at the reflector of the stopped vehicle ahead is larger during upward illumination than during downward illumination.

  Here, as described above, the object determination means is when the distance calculated by the distance calculation means is longer than a predetermined upper object determination distance and the intensity of the reflected wave is irradiated in the reference direction. Since an object that is larger when illuminated in the upward direction is determined as an upper installation object, even if a relatively tall stopped vehicle such as a truck is approached, this stopped vehicle is an upper installation object. Can be prevented from being erroneously determined.

Further, the irradiation direction switching unit described above is replaced with a configuration in which the irradiation direction in the vertical direction of the exploration wave irradiated by the irradiation unit is switched between the reference direction, the downward direction, and the upward direction,
It is good also as a structure which determines the above-mentioned object determination means about both the road surface installation thing mentioned above and an upper installation thing. The road surface installation object determination distance may be equal to the upper installation object determination distance, but is preferably set shorter than the upper installation object determination distance.

  In addition, when the detected object is not a stationary body, this object may be excluded from the determination target whether it is a road surface installation object or an upper installation object. In this way, the processing load for useless determination processing can be suppressed.

  According to the present invention, it is possible to distinguish and detect a road surface installation object and a stop vehicle with a particularly short height or a stop vehicle with a low reflector installation position.

  Further, it is possible to distinguish and detect an upper installation object and particularly a relatively tall stopped vehicle such as a truck.

  Embodiments of the present invention will be described below.

  FIG. 1 is a block diagram showing a configuration of a main part of a radar apparatus to which an object detection apparatus according to the present invention is applied. The radar apparatus 1 can detect an object located in front of an attached vehicle (own vehicle) and measure a distance to the detected object. The radar apparatus 1 uses laser light as an exploration wave. The radar apparatus 1 includes a control unit 2, an LD (Laser Diode) 3, an LD driving unit 4, a scanning unit 5, a vertical scanning position detection unit 6, a horizontal scanning position detection unit 7, and a PD (Photo Diode). 8, a light receiving unit 9, and a memory 10.

  The control unit 2 controls the operation of each part of the main body of the radar apparatus 1. The LD drive unit 4 controls the light emission of the LD 3 in accordance with an instruction from the control unit 2. The laser beam emitted from the LD 3 is irradiated to the front of the host vehicle through a light projecting lens 5a disposed to face the light emitting surface of the LD 3.

  The scanning unit 5 moves the light projecting lens 5a in accordance with an instruction from the control unit 2, and scans the laser light applied to the front of the host vehicle within a predetermined scanning range. The vertical scanning position detection unit 6 detects the scanning position of the laser beam in the vertical direction by the scanning unit 5 and outputs it to the control unit 2. Further, the horizontal scanning position detection unit 7 detects the scanning position of the laser beam in the horizontal direction by the scanning unit 5 and outputs it to the control unit 2. Further, the scanning unit 5 moves the light receiving lens 5b arranged to face the light receiving surface of the PD 8 in accordance with the scanning position of the laser light, that is, the position of the light projecting lens 5a. The reflected light that is reflected by the front object (for example, vehicle or road surface) of the laser beam irradiated in front of the host vehicle is collected by the light receiving lens 5b and is incident on the light receiving surface of the PD 8. The PD 8 outputs a signal corresponding to the amount of received laser light (reflected wave) received. The light receiving unit 9 processes the output signal of the PD 8, digitizes the amount of received light of the reflected wave, and outputs this to the control unit 2 as the intensity of the reflected wave. The control unit 2 stores the intensity of the input reflected wave in the memory 10 corresponding to the scanning position input from the vertical scanning position detection unit 6 and the horizontal scanning position detection unit 7. Further, the memory 10 stores a flag indicating whether or not the detected object is a road surface installation object or an object determined to be an upper installation object.

  The road surface installation referred to here is a road marking, a reflective object embedded in the road surface (so-called cat's eye) or the like, and the upper installation object is a footbridge or a signboard installed above. The road surface installation object and the upper installation object are not obstacles that prevent the vehicle from traveling.

  Furthermore, a vehicle speed sensor 20, a vehicle control unit 21, and the like are connected to the control unit 2. The vehicle speed sensor 20 detects the traveling speed of the host vehicle and inputs it to the control unit 2. The vehicle control unit 21 controls the traveling of the host vehicle according to the following traveling of the preceding vehicle, the braking of the host vehicle, or the like in accordance with the detected position of the preceding preceding vehicle or obstacle input from the control unit 2. I do.

  Here, the scanning unit 5 will be described in more detail. FIG. 2 is a diagram illustrating a configuration of the scanning unit. The scanning unit 5 includes a driving circuit 30, a horizontal driving coil 31, a vertical driving coil 32, a horizontal leaf spring 33, and a vertical leaf spring in addition to the light projecting lens 5a and the light receiving lens 5b. 34. The control unit 2 inputs a control signal indicating the scanning position to the drive circuit 30. The drive circuit 30 supplies a drive current to the horizontal direction drive coil 31 and the vertical direction drive coil 32 based on the input control signal. The horizontal driving coil 31 moves a support member that integrally supports the light projecting lens 5a and the light receiving lens 5b in the horizontal direction, and the vertical coil 32 integrally moves the light projecting lens 5a and the light receiving lens 5b. The supporting member to be supported is moved in the vertical direction. The support member is supported by a horizontal plate spring 33 so as to be movable in the horizontal direction, and supported by a vertical plate spring 34 so as to be movable in the vertical direction. Therefore, the support members (the light projecting lens 5a and the light receiving lens 5b) move to a horizontal position where the force generated in the horizontal driving coil 31 by the driving current and the reaction force generated in the horizontal leaf spring 33 are balanced. While stationary, it moves to a position where the force generated in the vertical driving coil 32 and the reaction force generated in the vertical leaf spring 34 are balanced, and is stationary.

  The positions of the light projecting lens 5 a and the light receiving lens 5 b are detected by a sensor (not shown), and the servo output is configured by inputting the sensor output to the drive circuit 30.

  In this way, the scanning unit 5 can move the light projecting lens 5a and the light receiving lens 5b in both the horizontal direction and the vertical direction. FIG. 3 shows an optical path of the laser light caused by the movement of the light projecting lens 5a and the light receiving lens 5b by the scanning unit 5. 3A shows the optical path of the laser light when the light projecting lens 5a and the light receiving lens 5b are moved in the horizontal direction, and FIG. 3B shows the light projecting lens 5a and the light receiving lens 5b being moved in the vertical direction. The optical path of the laser beam is shown. As described above, the light projecting lens 5a is disposed to face the light emitting surface of the LD3. The light receiving lens 5b is disposed to face the light receiving surface of the PD 8.

  The laser light emitted from the LD 3 is polarized in the center direction of the light projecting lens 5a. When the position of the light projecting lens 5a is at the center, the laser light is irradiated forward in front of the optical path shown by the solid line in FIGS. The laser light emitted in front of the front is reflected by a front object (for example, a vehicle or a road surface), enters the light receiving lens 5b along the optical path shown by the solid line in FIGS. 3A and 3B, and is received by the PD 8. Is done. Further, when the light projecting lens 5a is moved upward in the figure by the scanning unit 5, the laser beam is irradiated in the upward direction in the figure along the optical path indicated by the dotted lines in FIGS. 3 (A) and 3 (B). Is done. The irradiated laser light is reflected by an object in the upward direction in the figure, enters the light receiving lens 5b along the optical path indicated by the dotted line in FIGS. 3A and 3B, and is received by the PD 8.

  Thus, the scanning unit 5 can scan the laser light in the horizontal direction by moving the light projecting lens 5a and the light receiving lens 5b integrally in the horizontal direction. Similarly, the scanning unit 5 can scan the laser light in the vertical direction by moving the light projecting lens 35 and the light receiving lens 36 integrally in the vertical direction.

  Next, laser beam scanning in the radar apparatus 1 will be described. In the radar apparatus 1, horizontal scanning is composed of three frames. Each frame is a scan in the right direction. The irradiation direction of the laser beam in the vertical direction of each frame is a reference direction, a downward direction downward from the reference direction, and an upward direction upward from the reference direction. As shown in FIG. 4, the radar apparatus 1 has a horizontal scanning (hereinafter referred to as “upward scanning”) in which the laser beam irradiation direction in the vertical direction is set to the upward direction, and the laser beam irradiation direction in the vertical direction is set to the downward direction. By repeating the set horizontal scanning (hereinafter referred to as “downward scanning”) and the horizontal scanning (hereinafter referred to as “reference scanning”) in which the irradiation direction of the laser beam in the vertical direction is set as the reference direction, the horizontal direction is obtained. In addition, scanning in the vertical direction (two-dimensional scanning) is continuously performed. For each detected object, the radar apparatus 1 determines whether or not the object is a moving body or a stop body, and when the object is a stop body, the road surface such as a reflective object embedded in the road marking or the road surface. It is determined whether the object is an installation object or an upward installation object such as a pedestrian bridge or a signboard installed above.

FIG. 5 is a flowchart showing the operation of the radar apparatus. When the reference scanning in which the laser beam irradiation direction in the vertical direction is set as the reference direction is completed (s1), the control unit 2 reflects the laser beam for each horizontal detection region irradiated with the laser beam in the current reference scanning. The distance to the target is measured (s2). The distance L to the target uses a time difference (T2−T1) from timing T1 when the LD 3 emits the laser beam to timing T2 when the PD 4 receives the reflected light of the laser beam emitted from the LD 3.
L = c × (T2−T1) / 2 (c: propagation speed of laser light)
It can be calculated by

  The control unit 2 groups the targets detected in s2 (s3). In s3, for each target detected this time, the position is converted into two-dimensional coordinates on the horizontal plane. A movement vector is calculated using the position detected by the current reference scan, the position detected by the previous reference scan, and the speed of the host vehicle. Then, the targets whose positions are close and whose movement vectors are substantially the same are grouped as the same object. That is, targets belonging to the same group are detected as the same object. The control unit 2 calculates a movement vector using the traveling speed of the host vehicle input from the vehicle speed sensor 20. For each object detected by the grouping related to s3, the control unit 2 calculates a distance from the own vehicle, an orientation relative to the own vehicle, a width of the object, and the like (s4). And the control part 2 performs the obstruction determination process which determines whether it is obstructions, such as a stop vehicle which prevents driving | running | working of the own vehicle for every object detected this time (s5).

  FIG. 6 is a flowchart showing this obstacle determination process. The control unit 2 determines a detection object to be determined in this process from the detection objects detected by the current reference scan (s11). The control unit 2 resets a road surface installation flag indicating whether the detected object is a road surface installation object and an upper installation object flag indicating whether it is an upper installation object (s12). The control unit 2 determines whether or not the detected object as a determination target is a stationary body (s13). In s13, it is determined whether or not the object is a stationary body based on the previously calculated movement vector of the detected object. When determining that the object is not a stop object in s13, the control unit 2 determines whether there is an unprocessed detected object that has not been subjected to the present process among the detected objects detected in the current reference scan (s17). If there is a detected object to be processed, the process returns to s11. If there is no unprocessed detected object, this process ends.

  In s13, the process proceeds to s17 not only when it is determined that the detection object to be determined is a moving body, but also when it is not possible to determine whether the detection object is a stop body or a moving body.

  When determining that the object is a stopped body in s13, the controller 2 performs a road surface installation determination process for determining whether or not the object is a road surface installation (s14).

  FIG. 7 is a flowchart showing a road surface installation determination process. The control unit 2 determines whether the distance to the detected object detected by the current reference scan is shorter than the predetermined road surface installation determination distance D1 for the detected object to be determined in s11 described above ( s21). If the distance to the detected object is equal to or greater than the road surface installation determination distance D1, the control unit 2 determines that the detected object is not a road surface installation object, and ends the present process.

  If the distance to the detected object is shorter than the road surface installation determination distance D1, the control unit 2 determines that the intensity of the reflected wave from the detected object (the amount of light received by the PD8) obtained in the previous down scan is the previous time. It is determined whether or not the intensity of the reflected wave from the detected object obtained by the upper scanning is larger than the road surface installation object determination coefficient multiple (× α1) (s22). α1 is preferably a value of 1 or more. The control unit 2 determines that the intensity of the reflected wave from the detected object obtained in the previous lower scan is a road surface installation object determination coefficient multiple of the intensity of the reflected wave from the detected object obtained in the previous upper scan (× If it is determined that it is smaller than α1), this process is terminated.

  The control unit 2 determines that the intensity of the reflected wave from the detected object obtained in the previous lower scan is a road surface installation object determination coefficient multiple of the intensity of the reflected wave from the detected object obtained in the previous upper scan (× If it is determined that it is greater than α1), the intensity of the reflected wave from the detected object obtained in the previous lower scan is greater than the intensity of the reflected wave from the detected object obtained in the current reference scan. Is determined (s23). When the control unit 2 determines that the intensity of the reflected wave from the detected object obtained in the previous lower scan is equal to or lower than the intensity of the reflected wave from the detected object obtained in the current reference scan, The process ends. On the other hand, the control unit 2 determines that the intensity of the reflected wave from the detected object obtained in the previous lower scan is greater than the intensity of the reflected wave from the detected object obtained in the current reference scan. Then, a road surface installation determination flag is set for this detected object (s24), and this process is terminated. In s24, it is determined that the detected object is a road surface installation object.

  As described above, when the following four conditions (a) to (d) are satisfied for the detected object, the control unit 2 determines that the detected object is a road surface installation that does not hinder the traveling of the host vehicle. To do.

(A) Stopped object (b) The distance from the host vehicle is shorter than the predetermined road surface installation determination distance D1 (c) The intensity of the reflected wave obtained in the previous lower scan is the previous upper scan (D) The intensity of the reflected wave obtained in the previous down scan is the intensity of the reflected wave obtained in the current reference scan. Here, the irradiation state of the laser beam when the host vehicle passes over the road surface installation is shown in FIG. As shown in FIG. 8, the laser beam is irradiated on the road surface installation basically in the lower scan, but the laser beam is also emitted in the upper scan and the reference scan due to factors such as the spread of the laser beam and the road gradient. Road surface installations may be irradiated. An example of the received light amount distribution in this case is shown in FIG. As shown in FIG. 9, the received light amount of the reflected wave obtained by the lower scan becomes a size protruding from the received light amount obtained by the upper scan and the reference scan. From this, it can be determined based on the amount of received light whether or not the detected object is a road surface installation object under the above conditions (c) and (d).

  Note that the road surface installation object determination coefficient α1 in (c) is appropriately set based on the vertical irradiation angle difference of the laser light between the upper scanning and the lower scanning, the vertical spread angle of the laser light, and the like. For example, α1 may be about 10.

  On the other hand, as shown in FIG. 10, even when the host vehicle approaches a short vehicle or a stopped vehicle with a low reflector installation position, the upper scan, the reference scan, and the lower scan are performed at some distance from the stopped vehicle. The amount of light received by scanning may be in the state shown in FIG. In this case, the condition (b) described above is provided in order to prevent the stop vehicle from being erroneously determined as a road surface installation. As shown in FIG. 10A, the amount of light received by the upper scan, the reference scan, and the lower scan is as shown in FIG. 9 at a distance far from a short vehicle or a stopped vehicle with a low reflector installation position. However, as shown in FIG. 10B, when the vehicle approaches the vehicle to a certain extent, the received light amount obtained by the upper scan, the reference scan, and the lower scan is in the state shown in FIG. This is because when the host vehicle approaches the stopped vehicle to some extent, the reference scanning laser beam is reflected by the reflector even if the vehicle is a short vehicle or a stopped vehicle with a low reflector installation position.

  As described above, since the condition (b) relating to the road surface installation object determination distance D1 is provided, it is possible to prevent the detection object detected in the situation shown in FIG. 10A from being erroneously determined as a road surface installation object. As a result, it is possible to improve the determination accuracy of whether or not the detected object is a road surface installation.

  Note that the road surface installation object determination distance D1 may be appropriately set based on the vertical irradiation angle difference of the laser light between the downward scanning and the reference scanning, the vertical divergence angle of the laser light, and the like. May be set to about 30 m.

  Returning to FIG. 6, when the road surface installation determination process according to s14 is performed, the control unit 2 determines whether or not the road surface installation determination flag is set for the detected object that is the current processing target (s15). . That is, it is determined whether or not it is determined that the road surface installation object is determined in the road surface installation object determination process according to s14. When determining that the road surface installation determination flag is set in s15, the control unit 2 proceeds to s17. On the other hand, if it determines with the road surface installation determination flag not being set by s15, it will progress to s16, will perform the upper installation determination process shown below, and will progress to s17.

  FIG. 12 is a flowchart showing the upward installation object determination process. The control unit 2 determines whether or not the distance to the detected object (detected object to be determined in this process in s11) detected by the current reference scan is longer than a predetermined upper installation object determination distance D2. (S31). The upper installation object determination distance D2 is longer than the road surface installation object determination distance D1 described above. If the distance to the detected object is equal to or less than the upper installation object determination distance D2, the control unit 2 ends this process without determining that the object is an upper installation object.

  If the distance to the detection object is longer than the upper object determination distance D2, the control unit 2 obtains the intensity of the reflected wave from the detection object obtained in the previous upper scan in the previous lower scan. In addition, it is determined whether or not the intensity of the reflected wave from the detected object is greater than the upper object determination coefficient multiple (× α2) (s32). The control unit 2 determines that the intensity of the reflected wave from the detected object obtained in the previous upper scan is the upper object determination coefficient times the intensity of the reflected wave from the detected object obtained in the previous lower scan. If it is determined that it is not larger than (× α2), this process is terminated. α2 is preferably a value of 1 or more.

  The control unit 2 is configured such that the intensity of the reflected wave from the detected object obtained in the previous upper scan is multiplied by the upper object determination coefficient times the intensity of the reflected wave from the detected object obtained in the previous lower scan (× If it is determined that it is greater than α2), whether the intensity of the reflected wave from the detected object obtained in the previous upper scan is greater than the intensity of the reflected wave from the detected object obtained in the current reference scan Is determined (s33). When the control unit 2 determines that the intensity of the reflected wave from the detected object obtained in the previous upper scan is less than or equal to the intensity of the reflected wave from the detected object obtained in the current reference scan, Exit. On the other hand, when the control unit 2 determines that the intensity of the reflected wave from the detected object obtained in the previous upper scan is larger than the intensity of the reflected wave from the detected object obtained in the current reference scan, For this detected object, the upper object determination flag is set (s34), and this process is terminated. In s34, it is determined that the detected object is an upward installation object.

  As described above, when the following four conditions (f) to (i) are satisfied for the detected object, the control unit 2 determines that the detected object is an upward installation that does not hinder the traveling of the host vehicle. To do.

(F) Stopped object (g) The distance from the host vehicle is longer than a predetermined upper installation object determination distance D2. (H) The intensity of the reflected wave obtained in the previous upper scan is the previous lower scan. (I) The intensity of the reflected wave obtained in the previous upper scan is greater than the intensity of the reflected wave obtained in the current reference scan. Here, FIG. 13 shows an irradiation state of the laser beam when the host vehicle passes under the upper installation object (overhead signboard). As shown in FIG. 13, basically, the laser beam is irradiated to the upper object in the upper scan, but the laser beam is also raised in the reference scan and the lower scan due to factors such as the spread of the laser beam and the road gradient. The installation may be irradiated. An example of the received light amount distribution in this case is shown in FIG. As shown in FIG. 14, the amount of received light obtained by the upper scan becomes a size protruding from the amount of received light obtained by the reference scan and the lower scan. From this, it can be determined based on the amount of received light whether or not the detected object is an upward installation object under the above conditions (h) and (i).

  Note that the upper object determination coefficient α2 in (h) is appropriately set based on the vertical irradiation angle difference of the laser light between the upper scanning and the lower scanning, the vertical spread angle of the laser light, and the like. do it. The road surface installation determination coefficient α1 and the upper installation determination coefficient α2 may be the same value or may be different. For example, α2 may be set to about 10 which is the same as α1.

  On the other hand, as shown in FIG. 15, when the host vehicle approaches a tall stopped vehicle such as a truck, the amount of received light obtained by the upper scan, the reference scan, and the lower scan is the state shown in FIG. May be. In this case, in order to prevent the stop vehicle from being erroneously determined to be an upward installation object, the above-described condition (g) is provided. As shown in FIG. 15 (A), when approaching a tall stopped vehicle such as a truck, the amount of received light obtained by the upper scan, the reference scan, and the lower scan becomes the state shown in FIG. As shown in FIG. 11B, the received light amount obtained by the upper scan, the reference scan, and the lower scan is in the state shown in FIG. This is because when the host vehicle approaches a tall stopped vehicle such as a truck, the amount of laser light applied to the reflector of the stopped vehicle in the upper scan increases, and the laser beam of the reference scan is applied to the reflector. It is.

  As described above, since the condition (g) relating to the upper installation object determination distance D2 is provided, it is possible to prevent the detection object detected in the situation illustrated in FIG. 15A from being erroneously determined to be the upper installation object. As a result, it is possible to improve the determination accuracy as to whether or not the object is an upward installation object.

  The upper object determination distance D2 may be appropriately set based on the vertical irradiation angle difference of the laser light between the lower scanning and the reference scanning, the vertical spread angle of the laser light, and the like. May be set to about 50 m.

  When the obstacle determination process for s5 is completed for all the detected objects detected in the current reference scan, the control unit 21 notifies the vehicle control unit 21 and the like of the processing result (s6). The vehicle control unit 21 performs traveling control of the host vehicle based on the notified processing result.

  Moreover, in the said embodiment, although the determination concerning (c) and (d) mentioned above was performed in the road surface installation thing determination process, the determination concerning this (c) may be eliminated. Further, in the determination of (d), the intensity of the reflected wave obtained in the previous lower scan is a predetermined multiple of the intensity of the reflected wave obtained in the current reference scan (× α3, for example, α3 is about 1.2. ) May be replaced with a process for determining whether or not it is greater than.

  Similarly, the determination relating to (h) described above in the above-described upper object determination process may be eliminated. Further, in the determination according to (i), the intensity of the reflected wave obtained in the previous upper scan is a predetermined multiple of the intensity of the reflected wave obtained in the current reference scan (× α4, for example, α4 is about 1.2. ) May be replaced with a process for determining whether or not it is greater than.

  In addition, for a detected object that has not been confirmed to be a stationary body, the road surface installation object determination process and the upper object determination process are not performed, so execution of useless determination processes can be suppressed and the load on the apparatus main body can be reduced. be able to.

  In the above-described embodiment, the scan is repeated in the order of the upper scan, the lower scan, and the reference scan. The present invention is not limited to this, and the above-described obstacle determination process may be executed each time the reference scan is performed repeatedly in the order of the upper scan, the reference scan, the lower scan, and the reference scan.

  In the above-described embodiment, the present invention has been described by taking an apparatus that uses laser light as a search wave as an example. However, the present invention can also be applied to an object detection apparatus that uses a radio wave such as a millimeter wave as a search wave. . For example, when a millimeter wave is mechanically scanned and there is a reflected wave from the scanned direction, an apparatus configured to set the direction in which the millimeter wave is emitted as an object detection direction, or a phase difference in reflection of the emitted millimeter wave The present invention can also be applied to an apparatus configured to calculate the object detection direction based on the above. Detection of the distance to the detection object in a device that uses millimeter waves as the exploration wave can be performed based on the time difference from the irradiation of the millimeter wave to the detection of the reflected wave. As described above, the present invention can be applied to any apparatus that can detect the azimuth in which an object reflecting the emitted exploration wave exists, the distance to the object, and the intensity of the reflected wave.

It is a figure which shows the structure of the principal part of a radar apparatus. It is a figure which shows the structure of a scanning part. It is a figure explaining the optical path change of the laser beam by the movement of a light projection lens and a light reception lens. It is a figure explaining repetition of a top scan, a standard scan, and a bottom scan. It is a flowchart which shows operation | movement of a radar apparatus. It is a flowchart which shows an obstacle determination process. It is a flowchart which shows a road surface installation thing determination process. It is a figure which shows the irradiation condition of the laser beam when the own vehicle passes on the road surface installation thing. It is a figure which shows the light reception amount in case the own vehicle passes on the road surface installation thing in an upper scan, a reference | standard scan, and a lower scan. It is a figure which shows the irradiation condition of the laser beam when the own vehicle approaches a short vehicle or a stop vehicle with a low reflector installation position. Scan up. It is a figure which shows the light reception amount of the reflected wave from a preceding vehicle in a reference | standard scan and a downward scan. It is a flowchart which shows an upper installation thing determination process. It is a figure which shows the irradiation condition of the laser beam when the own vehicle passes under the installation object of the upper direction. It is a figure which shows the light reception amount in case the own vehicle passes under the installation object in an upper scan, a reference | standard scan, and a lower scan. It is a figure which shows the irradiation condition of the laser beam when the own vehicle approaches a tall stop vehicle, such as a truck.

Explanation of symbols

1-Radar device 2-Control unit 3-LD (Laser Diode)
4-LD driving unit 5-Scanning unit 6-Vertical scanning position detection unit 7-Horizontal scanning position detection unit 8-PD (Photo Diode)
9-Light receiving unit 10-Memory

Claims (5)

In an object detection device that is attached to a vehicle and detects an object located in front of the vehicle,
Irradiating means for irradiating exploration waves in front of the vehicle;
Detecting means for detecting a reflected wave of the exploration wave irradiated by the irradiation means;
Based on the time from when the irradiating means irradiates the exploration wave until the detection means detects the reflected wave, distance calculating means for calculating the distance to the object that reflected the exploration wave irradiated this time;
Irradiation direction switching means for switching the irradiation direction in the vertical direction of the exploration wave emitted by the irradiation means between a reference direction and a downward direction downward from the reference direction;
The distance calculated by the distance calculation means is shorter than the predetermined road surface installation object determination distance, and the intensity of the reflected wave is larger when irradiated in the downward direction than when irradiated in the reference direction. An object detection device comprising: object determination means for determining an object as a road surface installation object. In an object detection device that is attached to a vehicle and detects an object located in front of the vehicle,
Irradiating means for irradiating exploration waves in front of the vehicle;
Detecting means for detecting a reflected wave of the exploration wave irradiated by the irradiation means;
Based on the time from when the irradiating means irradiates the exploration wave until the detection means detects the reflected wave, distance calculating means for calculating the distance to the object that reflected the exploration wave irradiated this time;
An irradiation direction switching means for switching the irradiation direction in the vertical direction of the exploration wave irradiated by the irradiation means between a reference direction and an upward direction upward from the reference direction;
The distance calculated by the distance calculation means is longer than the predetermined upper object determination distance, and the intensity of the reflected wave is larger when irradiated in the upward direction than when irradiated in the reference direction. An object detection device comprising: object determination means for determining an object as an upward installation object. The irradiation direction switching means is a means for switching the irradiation direction in the vertical direction of the exploration wave irradiated by the irradiation means to the upward direction upward from the reference direction in addition to the reference direction and the downward direction. ,
The object determining means is longer in the upward direction than when the distance calculated by the distance calculating means is longer than a predetermined upper object determination distance and the intensity of the reflected wave is irradiated in the reference direction. The object detection apparatus according to claim 1, wherein the object detection apparatus is a unit that determines an object that is larger when irradiated as an upward installation object.   The object detection apparatus according to claim 3, wherein the road surface installation object determination distance is shorter than the upper installation object determination distance. Stop body determination means for determining whether the detected object is a stop body;
The object according to any one of claims 1 to 4, further comprising: a process target restriction unit that excludes the object that has not been determined by the stop object determination unit as a stop object from being processed by the object determination unit. Object detection device.

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