JP2011048641A - Object detection device and driving support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress that an alarm is executed as to an object not to become an alarm target. <P>SOLUTION: An object detection device for detecting a vehicle in the rear side of the own vehicle by a radar includes: an acquisition means to acquire the lane where the own vehicle runs when the own vehicle runs in a road that has two or more lanes in traveling direction of own vehicle; and a recognition condition change means which changes conditions when the target detected by the radar is recognized as the vehicle, based on the lane acquired by the acquisition means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an object detection device and a driving support device.

  In the warning system for the rear side object, an approaching vehicle that approaches at a relatively high relative speed and a blind spot vehicle that continues to run parallel with a relatively low relative speed are targeted for warning. Therefore, in order to determine the target vehicle, it is important to accurately detect the relative speed. Here, a technique is known in which an approaching object is detected in regions set independently on the right side and the left side according to the traveling speed (see, for example, Patent Document 1).

  However, there is a possibility that, for example, a guard rail or the like located on the rear side of the host vehicle is detected as another vehicle. For example, if the radar detects a guard rail on the center line that is not normally subject to warning while the host vehicle is traveling in an overtaking lane, there is a risk of giving an unnecessary warning to the driver. Further, even when the radar detects a utility pole on the road shoulder that is not normally a warning target while the host vehicle is making a left turn, an unnecessary warning may be given to the driver. These are caused by determining the alarm target using only the information of the own vehicle.

JP 2003-118523 A JP 2002-225657 A

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a technique capable of suppressing an alarm from being performed on an object that is not an alarm target.

In order to achieve the above object, the object detection apparatus according to the present invention employs the following means. That is, the object detection device according to the present invention is
In an object detection device that detects a vehicle behind the host vehicle with a radar,
An acquisition means for acquiring a lane in which the host vehicle is traveling when traveling on a road having a plurality of lanes in the traveling direction of the host vehicle;
Recognition condition changing means for changing a condition for recognizing a target detected by the radar as a vehicle based on a lane acquired by the acquiring means;
It is characterized by providing.

  A road having a plurality of lanes in the traveling direction of the host vehicle is a road having a plurality of lanes on one side and a plurality of lanes for the vehicle to travel in the same traveling direction as the host vehicle.

Here, on a road having a plurality of lanes in the traveling direction of the host vehicle, for example, when traveling in the rightmost lane, it is unlikely that another vehicle is traveling to the rear side of the right side. Then, even if the target is detected on the right rear side by the radar, the target is highly likely to be a roadside object such as a guardrail. On the other hand, when the target is detected on the left rear side by the radar while traveling in the rightmost lane, there is a high possibility that the target is another vehicle existing on the road. Similarly, while driving in the leftmost lane, even if a target is detected on the left rear side by the radar, the target is likely to be a roadside object such as a guardrail, and the right rear side If a target is detected, the possibility of another vehicle is high. Thus, even if the target is detected by the radar, the probability that the target is another vehicle differs depending on which side of the lane the host vehicle is traveling on or the rear side of the host vehicle. Therefore, if the conditions for recognizing the detected target as a vehicle are changed according to the lane in which the host vehicle is traveling, it is possible to suppress recognition of a roadside object or the like as a vehicle. Thereby, it can suppress that a false alarm is performed.

  In the present invention, the recognition condition changing means changes the condition between the right rear side and the left rear side of the host vehicle when the lane acquired by the acquiring means is the left lane or the right lane. can do.

  In other words, when traveling in the right and left lanes, the probability that another vehicle is present differs between the right rear side and the left rear side. By changing the condition according to this probability, the other vehicle can be recognized with high accuracy. Also, when traveling in lanes other than the right and left ends, the above conditions may be the same for the right rear side and the left rear side, and depending on the number of lanes to the right end and the number of lanes to the left end. The conditions may be changed.

  In the present invention, when the lane acquired by the acquiring unit is a rightmost lane, the recognition condition changing unit is detected on the right rear side of the target detected on the left rear side. The condition can be changed so that the target is not easily recognized as a vehicle.

  In the present invention, when the lane acquired by the acquiring unit is a leftmost lane, the recognition condition changing unit is detected on the left rear side rather than the target detected on the right rear side. The condition can be changed so that the target is not easily recognized as a vehicle.

  Here, “being difficult to be recognized as a vehicle” means that when a target is detected, conditions for recognizing it as a vehicle become severe. As described above, while traveling in the rightmost lane, there is a low probability that a rear side object exists on the right side. Therefore, even if a target is detected on the right rear side, it is highly probable that the target will not be alarmed. And if the target detected in the right rear side becomes difficult to recognize as a vehicle, it can control that a false alarm is performed. The same applies to the left rear side.

In the present invention, storage means for storing the number of times the target is detected by the radar for each lane;
Recognizing means for recognizing the target as a vehicle when the number of times stored by the storage means is equal to or greater than a threshold value in a specified period;
With
The recognition condition changing means can change the threshold value.

  That is, if a target is detected only by the radar, it is not recognized that it is a vehicle, and it is recognized that it is a vehicle only when a target that is equal to or greater than the threshold value is detected within a specified period. Thereby, it is suppressed that a false alarm is performed.

  When the threshold value is increased, the target is not recognized as a vehicle unless the target is detected more frequently. That is, the larger the threshold value, the more difficult the target is recognized as a vehicle. In this way, if the conditions are made stricter, it is possible to suppress an unnecessary alarm from being made on the side where the probability that an alarm target exists is low.

  Here, the specified period is a period required for recognizing a target as a vehicle, and may be set based on time or may be set based on a calculation cycle. The threshold value is the number of detections necessary for the target to be recognized as a vehicle.

In the present invention, storage means for storing the number of times the target is detected by the radar for each lane;
Recognizing means for recognizing the target as a vehicle when the number of times stored by the storage means is equal to or greater than a threshold value in a specified period;
With
The recognition condition changing unit can change the condition by causing the storage unit to store the number of times with a value different from an actual value.

  That is, instead of increasing the threshold value, the number of times the target is detected may be decreased. By storing the number of times the target has been detected smaller than the actual number, it is difficult for the target to be recognized as a vehicle because more targets must be detected before the number of times exceeds the threshold. Become. In this way, if the conditions are made stricter, it is possible to suppress an unnecessary alarm from being made on the side where the probability that an alarm target exists is low.

In the present invention, an acquisition means for acquiring road lane information is provided,
The acquisition means calculates a travel position of the host vehicle from a distance between a roadside object obtained by the radar and a travel locus of the host vehicle, and the host vehicle determines from the travel position and lane information acquired by the acquisition means. The traveling lane can be acquired.

  For example, the acquisition unit may store in advance information on the number of lanes on the road and the width of the lane, or may be obtained from an external signal. Moreover, you may acquire the information of the road lane by analyzing the image obtained with the camera. Roadside objects are objects that are stationary outside the road lane and are detected by the radar. From the distance between the position of the roadside object and the travel locus of the host vehicle, it can be determined which position on the road the host vehicle is traveling. The distance to the roadside object detected by the radar at this time is not used as it is, but it is calculated as the distance from the traveling locus of the own vehicle that the traveling direction of the own vehicle changes when traveling on a curve. This is to correct the deviation of the lateral position due to. By comparing the distance obtained in this way with the number of lanes and the lane width, the lane in which the host vehicle is traveling can be obtained.

In order to achieve the above object, the driving support apparatus according to the present invention employs the following means. That is, the driving support apparatus according to the present invention is
In the driving support device that supports the traveling of the host vehicle according to the detection result of the rear side object of the host vehicle by the radar,
An acquisition means for acquiring a lane in which the host vehicle is traveling when traveling on a road having a plurality of lanes in the traveling direction of the host vehicle;
Support condition changing means for changing the conditions for supporting the host vehicle based on the lane acquired by the acquiring means;
It is characterized by providing.

  For example, when the probability that a vehicle exists is low, the operating conditions for driving assistance are made stricter than when the probability is high. That is, even if a target is detected, it is highly probable that the target is a roadside object or the like, so that driving assistance is difficult to be performed. This may make it difficult to detect the target when the probability that the vehicle is present is low. When driving is supported according to the number of times the target is detected, driving may not be supported unless the number of times the target is detected is larger. Thereby, it can suppress that unnecessary driving assistance is performed. Driving assistance includes speed adjustment by issuing an alarm or controlling a brake or an engine.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a warning is performed with respect to the object which is not used as a warning object.

It is a block diagram which shows the object detection apparatus which concerns on an Example. It is a figure for demonstrating classification | category of a target. It is a figure for demonstrating a coordinate system. It is a figure for demonstrating the traveling position of the own vehicle. It is a figure for demonstrating the driving lane of the own vehicle. It is a figure for demonstrating the determination conditions for making a recognition determination flag ON. It is the flowchart which showed the flow when the object detection apparatus based on an Example operate | moves.

  Hereinafter, specific embodiments of the object detection device and the driving support device according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an object detection device 1 and a driving support device 100 according to the present embodiment. The object detection apparatus 1 according to the present embodiment is an apparatus that is mounted on a host vehicle traveling on a road and detects a rear side object such as another vehicle that is present on the rear side of the host vehicle. The driving support device 100 is a device that warns the driver when the rear side object is in a predetermined state. In the present embodiment, the case of left-hand traffic will be described, but the present invention can be similarly applied to right-hand traffic and one-way traffic.

  The object detection device 1 includes a millimeter wave radar 2, a radar ECU 3, a steering angle sensor 4, a yaw rate sensor 5, a wheel speed sensor 6, a navigation system 7, and a system ECU 8. The driving support device 100 includes the object detection device 1 and the operation device 9.

  The millimeter wave radar 2 is provided at the rear portion of the host vehicle, and detects the direction and distance from the host vehicle of a rear side object existing on the rear side of the host vehicle. The millimeter wave radar 2 scans the millimeter wave in a predetermined range on the rear side of the host vehicle and receives the reflected wave, thereby determining the distance to the rear side object in each direction in which the reflected wave is detected. To detect. Detection by the millimeter wave radar 2 is performed every predetermined time. The millimeter wave radar 2 sequentially outputs a signal corresponding to the detected direction and distance to the radar ECU 3.

  The radar ECU 3 calculates the position of a rear side object existing behind the host vehicle with respect to the host vehicle, and is configured mainly by a computer including a CPU, a ROM, and a RAM, for example. The radar ECU 3 includes an other vehicle relative distance calculation unit 31 and an other vehicle relative speed calculation unit 32.

  The other vehicle relative distance calculation unit 31 sequentially acquires signals output from the millimeter wave radar 2 and detects other vehicles existing behind the host vehicle based on the signals. Moreover, the other vehicle relative distance calculation part 31 calculates the distance with respect to the own vehicle of the detected other vehicle. The other vehicle relative distance calculation unit 31 outputs a signal corresponding to the calculation result to the system ECU 8.

  The other vehicle relative speed calculation unit 32 calculates the speed of the detected other vehicle relative to the host vehicle. The other vehicle relative speed calculation unit 32 outputs a signal corresponding to the calculation result to the system ECU 8.

  The millimeter wave radar 2 and the radar ECU 3 function as means for acquiring information on other vehicles.

  The steering angle sensor 4 is a sensor that is provided on the steering shaft of the host vehicle and detects the steering angle of the steering of the host vehicle. The steering angle sensor 4 includes a rotary encoder and the like, and detects the direction and magnitude of the steering angle input by the driver of the host vehicle. The steering angle sensor 4 outputs a steering angle signal corresponding to the detected direction and magnitude of the steering angle to the system ECU 8.

  The yaw rate sensor 5 is a sensor that is provided in a part of the host vehicle and detects the yaw rate of the host vehicle. The yaw rate sensor 5 detects the yaw rate of the host vehicle and outputs a signal corresponding to the detected yaw rate to the system ECU 8.

  The wheel speed sensor 6 is a sensor that is provided on each wheel and detects a wheel speed pulse. The wheel speed sensor 6 detects a wheel speed pulse at each wheel, and outputs a wheel speed pulse signal corresponding to the detected wheel speed pulse to the system ECU 8.

  The steering angle sensor 4, the yaw rate sensor 5, and the wheel speed sensor 6 function as means for acquiring information on the host vehicle.

  The navigation system 7 is a system that calculates the current position of the host vehicle based on a signal from an artificial satellite. The navigation system 7 stores the number of road lanes. A GPS device is connected to the navigation system 7, and signals from a plurality of artificial satellites arranged in outer space can be received by the GPS device to calculate the current position.

  The system ECU 8 calculates the traveling lane of the host vehicle, and determines whether or not to warn the rear side object detected by the radar based on the calculation result. For example, the CPU, the ROM, and the RAM It is composed mainly of the computer that contains it. The system ECU 8 acquires signals output from the radar ECU 3, the steering angle sensor 4, the yaw rate sensor 5, the wheel speed sensor 6, and the navigation system 7, and executes predetermined processing based on the acquired signals. Then, the travel lane of the host vehicle is calculated and it is determined whether or not an alarm is issued. The system ECU 8 includes a host vehicle travel lane calculation unit 81, a recognition threshold value calculation unit 82, and a recognition determination flag calculation unit 83.

  The own vehicle traveling lane calculation unit 81 calculates how far the own vehicle is from the roadside object from the roadside object information obtained by the millimeter wave radar 2 and the traveling locus of the own vehicle. Details will be described later.

  The recognition threshold value calculation unit 82 calculates a threshold value for warning the rear side object or a threshold value for recognizing the rear side object as a vehicle according to the traveling lane of the host vehicle. Then, the recognition threshold value calculation unit 82 is a condition when an alarm is given to the outside when the host vehicle is traveling on the right end or the left end lane, or a condition under which the outside target is recognized as a vehicle. The threshold value is calculated so that becomes severe. That is, the threshold value is calculated so that the warning is difficult to be performed or the target is not easily recognized as a vehicle. Details will be described later.

  The recognition determination flag calculation unit 83 calculates whether or not to issue a warning to the driver based on the calculation result of the recognition threshold value calculation unit 82 and other predetermined conditions. Is turned on, and the recognition determination flag is turned off when no alarm is given. Details will be described later.

  When the recognition determination flag is turned on, the system ECU 8 outputs a signal to the operation device 9. The operation device 9 is, for example, an LED 91 or an alarm device 92 using sound. Then, the driver is warned when the host vehicle and the other vehicle are in a predetermined state. The actuating device 9 can also include controlling the brake and engine.

  Next, the host vehicle travel lane calculation unit 81 will be described. First, roadside object information is acquired by the millimeter wave radar 2. Normally, the millimeter wave radar 2 outputs a plurality of target information for each stationary object, moving object, and the like. Among the plurality of target information, what is estimated to be a roadside object is extracted. For example, roadside objects such as guardrails are often detected as a plurality of targets because of their high reflection intensity.

  Therefore, for example, the following processing is performed on all targets and classified into “roadside objects” or “other than roadside objects”. In the following description, a case where the millimeter wave radar 2 detects a roadside object located on the left side of the own vehicle will be described. However, a roadside object located on the right side of the own vehicle or a roadside located on both the right side and the left side is described. Even if it is a thing, it is applicable similarly.

  FIG. 2 is a diagram for explaining the classification of the target. The arrow indicates the direction of relative speed with respect to the host vehicle 10. Here, the target information of the roadside object 11, the separated vehicle 12, and the approaching vehicle 13 is extracted. The roadside object 11 is a guard rail or the like, for example, and is present on the left side of the traveling lane. The separated vehicle 12 is a vehicle that is separated from the host vehicle 10 because the speed is slower than that of the host vehicle 10. The approaching vehicle 13 is a vehicle that approaches the host vehicle 10 because the speed is higher than that of the host vehicle 10.

  Here, the coordinate system used in this embodiment is shown in FIG. FIG. 3 is a diagram for explaining the coordinate system. The distance Y is a positive value in the traveling direction of the host vehicle 10, the relative speed V is a positive value in the traveling direction of the host vehicle 10, and the lateral position X is a positive value on the right side of the host vehicle 10. That is, in FIG. 2, the relative speed V of the roadside object 11 and the separating vehicle 12 with respect to the host vehicle 10 is a negative value, and the relative speed V of the approaching vehicle 13 is a positive value. In FIG. 2, the distance Y is a negative value for any of the roadside object 11, the separation vehicle 12, and the approaching vehicle 13. In FIG. 2, the lateral position from the traveling locus of the host vehicle 10 (the position where the distance between the traveling locus and the target is closest) is a negative value for the roadside object 11 and the separation vehicle 12, and the approaching vehicle 13 is positive. It is a value.

  When the following two conditions are both satisfied in the target detected by the millimeter wave radar 2, it is classified as “roadside object”, and when one or both of the conditions are not satisfied, “other than roadside object” is classified. ".

The first condition is that the absolute value of the relative speed of the target with respect to the host vehicle 10 is substantially equal to the absolute speed of the host vehicle 10. For example, the first condition is satisfied when the following expression is satisfied.
(Vehicle speed) + (− 5 km / h) ≦ | Target relative speed | ≦ (Vehicle speed) + (5 km / h)

  That is, since the roadside object 11 is stationary, if the target is the roadside object 11, the absolute value of the relative speed between the host vehicle 10 and the target is actually the same as the speed of the host vehicle 10. . This takes into account an error of 5 km / h. Since this value varies depending on the mounting position of the millimeter wave radar 2, the scanning range of the millimeter wave radar 2, or the like, the optimum value may be obtained through experiments or the like. In addition, since the separation vehicle 12 and the approaching vehicle 13 are moving at speeds, the first condition is difficult to be satisfied.

The second condition is that there are a plurality of targets within a specified range. For example, the second condition is satisfied when the following expression is satisfied.
| (Horizontal position of one target)-(Horizontal position of another target) |

  That is, when three or more other targets are detected within a range of 1 m in the distance Y direction around the one target, the second condition is satisfied. Here, since there are many roadside objects 11 with high reflection intensity, even if it is one roadside object 11, a plurality of points are detected as targets. That is, in the roadside object 11 such as a guardrail, a plurality of targets are detected in the range where the actual lateral position from the own vehicle 10 is almost the same. If it does so, it can be estimated that it is one roadside object 11 when the difference of the horizontal position of a some target is small respectively. The difference in lateral position at this time is 1 m, and the detected target is 3 or more. However, these are merely examples, and the optimum value depends on the mounting position of the millimeter wave radar 2, the scanning range of the millimeter wave radar 2, or the like. Since they are different, these values may be determined by experiments or the like. Since the separated vehicle 12 and the approaching vehicle 13 have high reflection strength at the four corners, the reflection point in the other vehicle is always the apex closest to the host vehicle 10, and in most cases, only one target is detected. .

  If both of the above two conditions are satisfied, the vehicle is classified as “roadside object”, and otherwise, it is classified as “other than roadside object”.

  Next, the traveling position of the host vehicle 10 is calculated. FIG. 4 is a diagram for explaining the travel position of the host vehicle 10. Based on the past travel locus of the host vehicle 10 and the current distance to the roadside object 11, the distance from the past vehicle 11 to the roadside object 11 is obtained as the travel position of the host vehicle. Here, the use of the travel locus of the host vehicle 10 without using the lateral position detected by the millimeter wave radar 2 as it is is when the host vehicle 10 is traveling on a curve, that is, when the traveling direction is changing. This is because it is difficult to accurately estimate the traveling position because the lateral position changes. That is, while traveling on a straight road, the lateral position detected by the millimeter wave radar 2 may be used as it is.

  In order to obtain the travel position of the host vehicle 10, all the target positions (X, Y) in the roadside object 11 obtained as described above are first averaged to calculate the average position (X, Y). Next, a difference in the X direction between the average position (X, Y) and the traveling locus of the host vehicle 10 is calculated and used as the traveling position of the host vehicle 10. The travel locus of the host vehicle 10 is always stored. The travel locus may be stored continuously, or the travel locus may be stored by storing the position of the host vehicle 10 for each predetermined time or distance. For example, discrete values for each calculation cycle calculated from the wheel speed obtained by the wheel speed sensor 6 and the yaw rate obtained by the yaw rate sensor 5 are used.

  Next, the lane information of the currently traveling road is acquired by the navigation system 7. First, the currently traveling road and the number of lanes of the road are searched from the position information of the host vehicle 10 obtained from the GPS device or the like and the road information stored in the navigation system 7. Based on the number of lanes on the road, the traveling lane of the host vehicle 10 is calculated. The number of lanes may be obtained by analyzing an image obtained from the camera, or may be obtained by receiving an external signal.

  FIG. 5 is a diagram for explaining the travel lane of the host vehicle. The travel lane of the host vehicle 10 is calculated based on the travel position of the host vehicle 10 and the number of lanes obtained from the navigation system 7 as described above. FIG. 5 shows a case where the host vehicle 10 is traveling in the second lane from the left of a road having three lanes.

First, the order from the leftmost travel lane to the lane in which the host vehicle 10 is traveling is calculated. Since the traveling position of the host vehicle 10 calculated as described above is a distance from the roadside object, this distance includes a shoulder on the outside of the lane. 1m outside this lane
Then, (| traveling position of own vehicle | -1 m) is the distance from the left end of the road to the own vehicle 10.

  Next, a lane width per lane is obtained from an image obtained by a camera mounted on the host vehicle 10. Note that the lane width may be obtained from information stored in the navigation system 7 or a signal received from the outside. If the lane width cannot be obtained from these, a general lane width corresponding to the speed of the host vehicle 10 may be used. Then, from the lane width per lane and the travel position of the host vehicle 10, it is possible to calculate the lane in which the host vehicle 10 is traveling from the left.

  Then, the traveling lane of the host vehicle 10 is classified into three from the lane in which the host vehicle 10 is traveling and the number of lanes obtained from the navigation system 7. That is, the vehicle is classified as “left side” when traveling in the left lane, “right” when traveling in the right lane, and “center” during traveling in other lanes.

  Since some navigation systems 7 have a function of detecting the travel lane of the host vehicle 10, classification may be performed using the function. Moreover, if such a function is combined with the above method, the detection accuracy can be further improved. In the present embodiment, the host vehicle travel lane calculation unit 81 corresponds to the acquisition means in the present invention.

  Next, the recognition threshold value calculation part 82 is demonstrated. The recognition threshold value calculation unit 82 changes the recognition threshold value depending on which of the three lanes classified into the lane in which the host vehicle 10 is traveling. Here, the recognition determination flag calculation unit 83 stores the number of detected targets for 10 cycles in the calculation cycle while accumulating for each lane. That is, the target numbers detected on the left rear side and the right rear side of the host vehicle 10 are accumulated for the past 10 cycles. When the integrated target number is equal to or greater than the recognition threshold, it is recognized that there is a target that can be an alarm target.

  And it becomes difficult to recognize the detected target as a warning object by enlarging the recognition threshold. That is, even if a target is detected, if the number of detections for 10 cycles in the calculation cycle is less than the recognition threshold, the roadside object 11 is recognized, for example. This recognition threshold is set on each of the left rear side and the right rear side of the host vehicle 10.

  When the classification of the traveling lane of the host vehicle 10 is “left side”, since there is a low probability that another vehicle exists on the left rear side, a left rear side recognition threshold (hereinafter referred to as a left recognition threshold) is used, for example. 9 and a right rear side recognition threshold (hereinafter referred to as a right recognition threshold) is set to 7, for example. Then, when the target is detected nine times or more on the left rear side in the 10 calculation cycles, the target is recognized as another vehicle. That is, it is recognized that there is another vehicle on the left rear side. Moreover, when a target is detected seven times or more in the right rear side in the 10 calculation cycles, the target is recognized as another vehicle. That is, it is recognized that there is another vehicle on the right rear side. Thus, when the classification of the traveling lane of the host vehicle 10 is “left side”, the left recognition threshold value is set larger than the right recognition threshold value. As a result, if more targets are not detected on the left rear side than on the right rear side, it is not recognized that there is another vehicle to be alarmed.

Further, when the traveling lane classification of the host vehicle 10 is “right side”, the probability of the presence of another vehicle on the right rear side is low, so the right recognition threshold is set to 9, for example, and the left recognition threshold is set to 7, for example. . Then, when the target is detected nine times or more on the right rear side in the 10 calculation cycles, the target is recognized as another vehicle. That is, it is recognized that there is another vehicle on the right rear side. Moreover, when a target is detected seven times or more on the left rear side in the 10 calculation cycles, the target is recognized as another vehicle. That is, it is recognized that there is another vehicle on the left rear side. Thus, when the classification of the traveling lane of the host vehicle 10 is “right side”, the right recognition threshold value is set larger than the left recognition threshold value. As a result, if more targets are not detected on the right rear side than on the left rear side, it is not recognized that there is another vehicle to be alarmed.

  Furthermore, when the traveling lane classification of the host vehicle 10 is “center”, it is assumed that the probability that another vehicle exists on the right rear side and the left rear side is equal. For this reason, the right recognition threshold is set to 7, for example, and the left recognition threshold is set to 7, for example. Then, when the target is detected seven times or more on the right rear side in the 10 calculation cycles, the target is recognized as another vehicle. That is, it is recognized that there is another vehicle on the right rear side. Moreover, when a target is detected seven times or more on the left rear side in the 10 calculation cycles, the target is recognized as another vehicle. That is, it is recognized that there is another vehicle on the left rear side. Thus, when the traveling lane classification of the host vehicle 10 is “center”, the condition for recognizing that another vehicle exists is the same for the left rear side and the right rear side.

  Thus, the conditions for recognizing a target as a vehicle are changed based on the lane. Moreover, since the conditions for operating the operating device 9 are changed, it can be said that the conditions for assisting the host vehicle 10 are changed based on the lane. In this embodiment, the calculation cycle is 10 cycles, but other values may be used. Also, the recognition threshold value may be a value other than 9 or 7. Since these vary depending on, for example, the mounting position of the millimeter wave radar 2, optimal values may be obtained through experiments or the like. The cumulative number of targets for each lane is hereinafter referred to as lane probability. That is, the target is recognized as a vehicle when the lane probability is greater than or equal to the recognition threshold. This recognition is performed by the recognition determination flag calculation unit 83.

  In this embodiment, the recognition threshold value is changed according to the traveling lane of the host vehicle 10, but instead, the number of detected targets is changed according to the traveling lane of the host vehicle 10. May be accumulated. In this case, the recognition threshold value is constant and the same value regardless of which lane the vehicle is traveling on. Moreover, you may combine these.

  For example, when the traveling lane classification of the host vehicle 10 is “left side”, the left recognition threshold and the right recognition threshold are set to 7. And when the target is detected, if it is detected on the right rear side, it is integrated as one target as it is, and if it is detected on the left rear side, for example 0.78 Accumulate as a mark. That is, when the target is detected nine times or more in the left rear side of the 10 calculation cycles, the accumulated number in the left rear side is 7 or more, so that there is another vehicle on the left rear side. Be recognized. In addition, when a target is detected seven times or more in the right rear side of the ten calculation cycles, it is recognized that another vehicle exists on the right rear side.

  That is, when the traveling lane classification of the host vehicle 10 is “left side”, it is not recognized that there is another vehicle unless more targets are detected on the left rear side than on the right rear side. The same can be considered even when the traveling lane classification of the host vehicle 10 is “right” and “center”. In this embodiment, the recognition threshold value calculation unit 82 corresponds to the recognition condition changing means or the support condition changing means in the present invention.

Next, the recognition determination flag calculation unit 83 will be described. The recognition determination flag calculation unit 83 calculates the recognition determination flag by using the target number and the recognition threshold stored while integrating for each lane. In addition, for example, a determination condition defined by ISO is used for the calculation of the recognition determination flag. Here, the left recognition determination flag is a flag that is turned on when there is another vehicle to be alarmed on the left rear side, and is turned off when there is no vehicle. Similarly, the right recognition determination flag is a flag that is turned on when there is another vehicle to be alarmed on the right rear side, and is turned off when there is no vehicle. For example, the left recognition determination flag is turned ON when the cumulative number of the left rear side is greater than or equal to the left recognition threshold and other determination conditions are satisfied. Further, the right recognition determination flag is set to ON when the cumulative number on the right rear side is equal to or greater than the right recognition threshold value and other determination conditions are satisfied. When the right recognition determination flag and the left recognition determination flag are not distinguished, they are simply referred to as a recognition determination flag. When the recognition determination flag is turned ON, the operation device 9 operates. In this embodiment, the recognition determination flag calculation unit 83 corresponds to the storage unit and the recognition unit in the present invention.

  Here, FIG. 6 is a diagram for explaining a determination condition for turning on the recognition determination flag. In this embodiment, the following six determination conditions are used in addition to the above lane probability.

  The first determination condition is the time until the front surface of the other vehicle 20 reaches the rear end of the host vehicle 10 (hereinafter referred to as TTC). The TTC is calculated based on the relative distance and the relative speed. This TTC is used to determine whether or not the other vehicle 20 is approaching. For example, the recognition determination flag can be turned ON when the vehicle is below a threshold value. This threshold value is a value defined by ISO, for example.

  The second determination condition is a relative distance between the host vehicle 10 and the other vehicle 20. For this, a value calculated by the other vehicle relative distance calculation unit 31 is used. This relative distance is used to determine whether or not there is a vehicle in the blind spot. For example, the recognition determination flag can be turned ON when the vehicle is below a threshold value. The threshold value is a value defined by ISO, for example.

  The third determination condition is a traveling direction component of the host vehicle 10 of the relative speed between the host vehicle 10 and the other vehicle 20. This is calculated using two of the relative speed information and distance information of the millimeter wave radar 2. Then, the recognition determination flag can be turned ON when the traveling direction component of the host vehicle 10 having a relative speed is equal to or greater than a threshold value.

  The fourth determination condition is the lateral position of the other vehicle 20. The lateral position here is the distance between the other vehicle 20 and the traveling locus of the host vehicle 10. For example, the lateral position is obtained from the saved past travel position of the host vehicle 10 and the absolute position of the other vehicle 20. That is, a travel locus is obtained from the travel history of the host vehicle 10, and a distance from the travel locus to the other vehicle 20 is obtained. The recognition determination flag can be turned ON when the lateral position is less than or equal to the threshold value. The absolute position of the other vehicle 20 can be obtained based on the calculation result by the other vehicle relative distance calculation unit 31.

  The fifth condition is existence probability. The existence probability is obtained by quantifying the continuity of the target supplement status of the millimeter wave radar 2. This can indicate how much the object is present. The greater the number of times the target is detected, the higher the existence probability. Then, the fixed value is adjusted depending on the determination threshold of the millimeter wave radar 2, the presence / absence of extrapolation, and the like. For example, when there is extrapolation, the probability increase is smaller than when there is no extrapolation. When the existence probability is equal to or higher than the threshold, the recognition determination flag can be turned ON.

  The sixth determination condition is the speed of the host vehicle 10. The recognition determination flag can be turned ON when the speed of the host vehicle 10 exceeds a threshold value. The threshold value is 60 km / h, for example, and is obtained by experiments or the like. The speed of the host vehicle 10 is calculated based on the wheel speed pulse signal output from the wheel speed sensor 6.

  All of these determination conditions do not need to be satisfied. For example, the relative distance is used to determine whether or not there is a vehicle running parallel in the blind spot, and the TTC is used to determine whether or not an approaching vehicle is present, so both conditions are satisfied. There is no need. That is, the recognition determination flag is set to ON when any one of the relative distance or TTC is satisfied and all the other conditions are satisfied, and otherwise the recognition determination flag is set to OFF.

  Next, FIG. 7 is a flowchart showing a flow when the object detection apparatus 1 according to this embodiment operates. This routine is repeatedly executed every predetermined time.

  In step S101, roadside object information is acquired. In this step, all road targets are classified as “roadside objects” or “other than roadside objects”.

  In step S102, the traveling position of the host vehicle 10 is calculated. The travel position of the host vehicle 10 is calculated based on how far the host vehicle 10 is from the roadside object.

  In step S103, lane information is acquired. In this step, the lane information of the currently traveling road is acquired by the navigation system 7. This includes information on the number of lanes and the lane width. The road on which the host vehicle 10 is traveling is detected from the position information of the host vehicle 10 and the information on the number of lanes and the lane width of the road stored in the navigation system 7 is compared with the information on the road on which the host vehicle 10 is traveling. Get the number of lanes and lane width.

  In step S104, the travel lane of the host vehicle 10 is calculated. The travel lane of the host vehicle 10 is calculated based on the travel position of the host vehicle 10 and the number of lanes and the lane width obtained from the navigation system 7.

  In step S105, a recognition determination condition is calculated. In this step, determination conditions other than the target number and the recognition threshold value integrated in each lane are calculated. For example, TTC, relative distance, etc.

  In step S106, it is determined whether or not the traveling lane of the host vehicle is classified as “left side”. If an affirmative determination is made in step S106, the process proceeds to step S107, and if a negative determination is made, the process proceeds to step S108.

  In step S107, the left recognition threshold is increased compared with the right recognition threshold. That is, the left recognition threshold value and the right recognition threshold value are values when the travel lane of the host vehicle 10 is classified as “left side”. For example, the left recognition threshold is 9 and the right recognition threshold is 7.

  In step S108, it is determined whether or not the traveling lane of the host vehicle is classified as “right”. If an affirmative determination is made in step S108, the process proceeds to step S109, and if a negative determination is made, the process proceeds to step S110.

  In step S109, the right recognition threshold is increased compared to the left recognition threshold. That is, the left recognition threshold value and the right recognition threshold value are values when the traveling lane of the host vehicle 10 is classified as “right side”. For example, the right recognition threshold is 9 and the left recognition threshold is 7.

  In step S110, the right recognition threshold and the left recognition threshold are set to the same value. That is, the left recognition threshold value and the right recognition threshold value are values when the traveling lane of the host vehicle is classified as “center”. For example, the right recognition threshold is 7 and the left recognition threshold is 7.

  In step S111, a recognition determination flag is calculated. The left recognition determination flag is set to ON when the number of integrations on the left rear side is equal to or greater than the left recognition threshold and other determination conditions are satisfied. Further, the right recognition determination flag is set to ON when the cumulative number on the right rear side is equal to or greater than the right recognition threshold value and other determination conditions are satisfied. Then, when the left recognition determination flag or the right recognition determination flag is turned ON, the operation device 9 is operated in accordance with it and an alarm is given.

  As described above, according to the present embodiment, the condition for recognizing a target as a vehicle or the condition for performing an alarm is changed between the left rear side and the right rear side according to the lane in which the host vehicle is traveling. It is possible to suppress erroneous warnings caused by roadside objects and the like.

DESCRIPTION OF SYMBOLS 1 Object detection apparatus 2 Millimeter wave radar 3 Radar ECU
4 Steering angle sensor 5 Yaw rate sensor 6 Wheel speed sensor 7 Navigation system 8 System ECU
DESCRIPTION OF SYMBOLS 9 Actuation device 10 Own vehicle 11 Roadside object 12 Separation vehicle 13 Approaching vehicle 20 Other vehicle 31 Other vehicle relative distance calculation part 32 Other vehicle relative speed calculation part 81 Own vehicle travel lane calculation part 82 Recognition threshold value calculation part 83 Recognition determination flag calculation part 91 LED
92 Alarm device 100 Driving support device

Claims (7)

In an object detection device that detects a vehicle behind the host vehicle with a radar,
An acquisition means for acquiring a lane in which the host vehicle is traveling when traveling on a road having a plurality of lanes in the traveling direction of the host vehicle;
Recognition condition changing means for changing a condition for recognizing a target detected by the radar as a vehicle based on a lane acquired by the acquiring means;
An object detection apparatus comprising:   The recognition condition changing means changes the condition between the right rear side and the left rear side of the host vehicle when the lane acquired by the acquiring means is a left lane or a right lane. Item 4. The object detection apparatus according to Item 1.   The recognition condition changing means recognizes a target detected on the right rear side as a vehicle rather than a target detected on the left rear side when the lane acquired by the acquisition means is the rightmost lane. The object detection apparatus according to claim 2, wherein the condition is changed so as to be difficult to be performed.   The recognition condition changing means recognizes a target detected on the left rear side as a vehicle rather than a target detected on the right rear side when the lane acquired by the acquiring means is the leftmost lane. The object detection apparatus according to claim 2, wherein the condition is changed so as to be difficult to be performed. Storage means for storing the number of times the target is detected by the radar for each lane;
Recognizing means for recognizing the target as a vehicle when the number of times stored by the storage means is equal to or greater than a threshold value in a specified period;
With
5. The object detection apparatus according to claim 2, wherein the recognition condition changing unit changes the condition by changing the threshold value. 6. Storage means for storing the number of times the target is detected by the radar for each lane;
Recognizing means for recognizing the target as a vehicle when the number of times stored by the storage means is equal to or greater than a threshold value in a specified period;
With
5. The object detection apparatus according to claim 2, wherein the recognition condition changing unit changes the condition by causing the storage unit to store the number of times with a value different from an actual value. 6. . In the driving support device that supports the traveling of the host vehicle according to the detection result of the rear side object of the host vehicle by the radar,
An acquisition means for acquiring a lane in which the host vehicle is traveling when traveling on a road having a plurality of lanes in the traveling direction of the host vehicle;
Support condition changing means for changing the conditions for supporting the host vehicle based on the lane acquired by the acquiring means;
A driving support apparatus comprising:

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