JP4956321B2 - Vehicle object detection device - Google Patents

Description

  The present invention relates to a vehicle object detection device.

Conventionally, for example, a laser beam is irradiated while scanning the front of the host vehicle, a reflection point on the surface of the object is detected by reflected light from an object existing around the host vehicle, and the position of the object is detected from the plurality of reflection points. In addition, an object recognition device that obtains a relative speed, predicts the center position of an object in the next process, and sets a search range for the object, thereby distinguishing a plurality of objects around the host vehicle is known ( For example, see Patent Document 1).
Japanese Patent Application Laid-Open No. 2004-347489

By the way, in the object recognition apparatus according to the above prior art, the position and relative speed of the object are detected from a plurality of reflection points on the surface of the object. For example, for other vehicles crossing the traveling direction of the own vehicle, etc. Like the detected reflection point, due to the fluctuation of the reflection intensity of the laser beam on the surface of the vehicle body, the reflection point at the vehicle center where the reflection intensity is relatively weak is not detected, and the reflection intensity is relatively low. If a strong reflection point at the front and rear of the vehicle is detected, a single object may be recognized as a plurality of different objects.
In addition, for example, when a four-wheeled vehicle and a two-wheeled vehicle run side by side in close proximity, a plurality of objects can be separated only by the relative speed (that is, the direction and magnitude of the movement vector) obtained from a plurality of reflection points. Recognition may be difficult, and there is a problem that appropriate object recognition cannot be performed.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle object detection device that can appropriately detect an object.

  In order to solve the above-described problems and achieve the object, the vehicle object detection device according to the first aspect of the present invention transmits an electromagnetic wave over a predetermined angle around the vehicle at a predetermined time interval. Transmitting / receiving means (for example, the radar device 15 in the embodiment) for receiving the reflected wave of the electromagnetic wave from an object existing in the vicinity, and the electromagnetic wave transmitted by the transmitting / receiving means is reflected on the surface of the object. Reflection point calculation means for calculating a reflection point when performing the reflection (for example, the reflection point calculation unit 32 in the embodiment), and the reflection points having an interval between the reflection points of each electromagnetic wave less than a first predetermined value. Segmentation means that recognizes that it exists in the same segment (for example, segment setting unit 34 in the embodiment), and centroid calculation means that calculates the centroid of the segment (for example, centroid calculation unit 35 in the embodiment) Relative speed calculation means (for example, a relative speed calculation unit 36 in the embodiment) for calculating a relative speed between the vehicle and the object based on the center of gravity is provided, and the segmentation means constitutes a first segment. The interval between the first reflection point and the second reflection point constituting the second segment is less than a second predetermined value, and the correlation value between the relative speed of the first segment and the relative speed of the second segment is When the value is equal to or greater than a third predetermined value, the first segment and the second segment are recognized as the same segment.

Furthermore , the reflection point calculation means sets the reflection point with the latest timing calculated among the reflection points constituting the first segment as the first reflection point, and among the reflection points constituting the second segment. The reflection point with the earliest calculated timing is set as the second reflection point, and the segmentation means reflects the reflection at each combination of the reflection point constituting the first segment and the reflection point constituting the second segment. The first segment and the second segment are recognized as the same segment when the interval between the first and second reflection points is the smallest among the intervals between the points.

  According to the vehicle object detection device of the first aspect of the present invention, the distance between the first reflection point constituting the first segment and the second reflection point constituting the second segment is less than a second predetermined value, In addition, when the correlation value (for example, the inner product of the movement vectors) between the relative speed of the first segment and the relative speed of the second segment is equal to or greater than a third predetermined value, the first segment and the second segment are identical. By recognizing a segment, a single object is recognized as a plurality of different objects even when the first segment and the second segment are formed from reflection points with respect to the single object. Can be prevented.

Furthermore , even when the first segment and the second segment are configured from the reflection point with respect to a single object when the electromagnetic wave is transmitted while scanning in an appropriate direction such as the horizontal direction, for example, the scanning direction The first reflection point calculated at the latest timing in the first segment on the rear side of the first and the second reflection point calculated at the earliest timing on the second segment on the front side in the scanning direction, for example, The first reflection point and the second reflection point are adjacent to each other in the scanning direction, and the distance between the reflection points in the combination of the appropriate reflection point that forms the first segment and the appropriate reflection point that forms the second segment. The distance between the reflection points in combination with the two reflection points is minimized. Thereby, even when the first segment and the second segment are configured from the reflection points with respect to a single object, it is possible to prevent the single object from being recognized as a plurality of different objects. .

Hereinafter, a vehicle object detection device according to an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, for example, the vehicle object detection device 10 according to the embodiment of the present invention includes a yaw rate sensor 11, a steering angle sensor 12, a vehicle speed sensor 13, a navigation device 14, a radar device 15, and a control. A device 16, a brake actuator 17, and an alarm device 18 are provided.

The yaw rate sensor 11 detects the yaw rate of the host vehicle, that is, the amount of change in the yaw angle, which is the rotation angle around the vertical axis of the center of gravity of the vehicle.
The steering angle sensor 12 detects an actual steering angle (steering angle) according to the steering angle of the host vehicle (for example, the direction and magnitude of the steering angle input by the driver).
The vehicle speed sensor 13 detects the speed (vehicle speed) of the host vehicle.
The navigation device 14 detects the current position of the host vehicle from a positioning signal received from, for example, an artificial satellite, a base station, or the like, or an autonomous navigation calculation process based on detection signals from the sensors 11 and 13, and Map matching is performed on predetermined road data based on the information, and the detection result of the current position is corrected. In addition, while controlling the map display on a monitor (not shown) with respect to the current position or appropriate position information input by an operator via various input devices (for example, a touch panel), Processing such as route search and route guidance is performed.

The radar device 15 transmits an electromagnetic wave such as a laser beam or a millimeter wave toward a detection area ahead of the traveling direction of the own vehicle, and the transmitted electromagnetic wave is reflected by an object existing in the detection area. A beam scan radar 21 that receives the generated reflected wave and a control unit 22 that generates a beat signal by mixing the transmitted electromagnetic wave and the received electromagnetic wave (reflected wave) are provided.
The detection area of the radar apparatus 15 is divided into a plurality of scanning areas set with respect to the three-dimensional angular direction, and the radar apparatus 15 scans the detection area divided into the plurality of scanning areas.

  The control device 16 includes, for example, a host vehicle trajectory estimation unit 31, a reflection point calculation unit 32, a reflection point storage unit 33, a segment setting unit 34, a center of gravity calculation unit 35, a relative speed calculation unit 36, and vehicle control. Part 37.

  The own vehicle trajectory estimation unit 31 estimates the travel trajectory of the own vehicle based on the detection signals of the sensors 11, 12, and 13 and information on the current position of the own vehicle calculated by the navigation device 14.

The reflection point calculation unit 32 is based on the beat signal output from the control unit 22 of the radar device 15, and the position where the reflected wave received by the radar 21 is generated, that is, the electromagnetic wave transmitted from the radar 21 is converted into the external environment of the own vehicle. The reflection point at the time of reflection on the surface of the object existing in is calculated.
The reflection point storage unit 33 stores a plurality of reflection points calculated as the radar apparatus 15 scans.

  The segment setting unit 34 divides a plurality of reflection points acquired from the reflection point calculation unit 32 and the reflection point storage unit 33 into groups related to the same object for each scanning region. A process for determining whether or not the distance between the reflection points is less than a predetermined first predetermined value is performed on the reflection points, and groups related to the same object are generated. A plurality of scans are combined with a group generated for each scan region in order to combine groups related to the same object across a plurality of scan regions (for example, between adjacent scan regions in a three-dimensional space). It is determined whether or not each other's groups relate to the same object between the regions, and a group is generated by combining the groups related to the same object according to the determination result.

  In addition, the segment setting unit 34 determines whether or not the segment at the (N−1) time point and the segment at the N time point by an arbitrary natural number N are the same for a plurality of time-series segments. In addition, the gravity center calculation unit 35 calculates the gravity center position at one point ahead (that is, N points in time) estimated by the Kalman filter or the like for the segment at the point (N-1), and the gravity center calculation unit 35 calculates It is determined whether or not the position of the center of gravity of the segment at time N is close.

  Furthermore, the segment setting unit 34 forms, for example, a time series with respect to the relative speed of each segment calculated by the relative speed calculation unit 36 based on the center of gravity of each segment calculated by the center of gravity calculation unit 35 (N− 1) It is determined whether or not the correlation value (for example, inner product of movement vectors) between the relative speed of the segment at the time point and the relative speed of the segment at the time point N is high.

  In the segment setting unit 34, the center-of-gravity position at one point ahead (that is, point N) estimated from the segment at point (N-1) is close to the barycentric position of the segment at point N. When it is determined that the correlation value (for example, inner product of movement vectors) between the relative velocity of the segment at the time (N-1) and the relative velocity of the segment at the time N is high (N-1 ) The segment at the time point and the segment at the N time point are recognized as the same segment.

  Furthermore, the segment setting unit 34 performs the processing for segment separation or fusion, for example, for the appropriate first segment and second segment that are different from each other, the timing calculated among the reflection points constituting the first segment is the most. The reflection point that is the slowest reflection point is the first reflection point, the reflection point that has the earliest timing calculated among the reflection points that constitute the second segment is the second reflection point, and the reflection point and the second segment that constitute the first segment are Of the intervals between the reflection points in each combination with the reflection points to be configured, when the interval between the first and second reflection points is minimized, the first segment and the second segment are made the same segment ( That is, it is recognized as a single segment). When there is another combination in which the interval between the first and second reflection points is not the minimum and the interval between the reflection points is the minimum, the first segment and the second segment are different from each other (that is, a plurality of segments). Different segments).

For example, as shown in FIG. 2 (a), the first and second reflection points in the interval between the reflection points for each combination of the reflection points constituting the first segment and the reflection points constituting the second segment. When the distance L between them is the smallest, the first segment and the second segment are the same segment (that is, a single segment) and are a single object (for example, a single other vehicle, etc.) ) Is recognized as a segment set for.
On the other hand, for example, as shown in FIG. 2B, the first and second of the intervals between the reflection points for each combination of the reflection points constituting the first segment and the reflection points constituting the second segment. The distance L (>Lb> La) between the reflection points is not the minimum, and other combinations that minimize the distance between the reflection points (for example, the first reflection point and the reflection corresponding to the distance La in FIG. 2B) When there is a combination with the point a), the first segment and the second segment are different segments (that is, a plurality of different segments), and a plurality of different objects (for example, a plurality of other vehicles, etc.) ) Is recognized as a segment set for.

  The vehicle control unit 37 sets an alarm output timing, output contents, and the like according to the relative speed between the host vehicle and the object output from the relative speed calculation unit 36, for example, and detects occurrence of a collision between the object and the host vehicle. Execution timing and control details (for example, deceleration during deceleration control, etc.) for controlling the traveling state of the host vehicle so as to reduce damage during avoidance or collision are set. The control signal for controlling the deceleration operation by the brake actuator 17, the control signal for controlling the steering operation of the steering mechanism (not shown) of the own vehicle, and the notification operation of the alarm device 18 are controlled according to the set control content. Outputs control signals and the like.

The alarm device 18 includes, for example, a tactile transmission device, a visual transmission device, and an auditory transmission device.
The tactile transmission device is, for example, a seat belt device, a steering control device, or the like, and generates a predetermined tension on the seat belt, for example, according to a control signal input from the vehicle control unit 37 so that the passenger of the own vehicle can feel There is a possibility of collision with an object by applying a visually perceptible tightening force or by generating vibration (steering vibration) that can be perceived tactilely by the driver of the host vehicle on the steering wheel, for example. Is recognized by the passenger.
The visual transmission device is, for example, a display device or the like, and according to a control signal input from the vehicle control unit 37, for example, by displaying predetermined alarm information on the display device or blinking a predetermined alarm light. Let the occupant recognize that there is a possibility of collision with the object.
The auditory transmission device is, for example, a speaker or the like, and there is a possibility of occurrence of a collision with an object by outputting a predetermined alarm sound or voice according to a control signal input from the vehicle control unit 37. Is recognized by the passenger.

  The vehicle object detection device 10 according to the present embodiment has the above-described configuration. Next, the operation of the vehicle object detection device 10, in particular, a plurality of reflection points calculated in accordance with the scanning of the radar device 15 is obtained. The processing operation will be described.

  First, for example, in step S01 shown in FIG. 3, in order to divide a plurality of reflection points calculated along with scanning of the radar device 15 for each scanning region into groups related to the same object, for each scanning region, A process of determining whether or not the distance between the reflection points is less than a predetermined first predetermined value is performed on the plurality of reflection points, and the reflection points having a determination result of “YES” are classified into the same group. .

  Next, in step S02, a group related to the same object is joined across a plurality of scanning regions (for example, between adjacent scanning regions in a three-dimensional space) to the group generated for each scanning region. For this reason, it is determined whether or not each group is related to the same object between a plurality of scanning regions, and the groups related to the same object are combined according to the determination result to generate a segment.

  Next, in step S03, in order to determine whether or not the segment at time (N-1) and the segment at time N according to an arbitrary natural number N are the same for a plurality of time-series segments. Furthermore, whether or not the centroid position at one point ahead (that is, N point) estimated by the Kalman filter or the like for the segment at (N-1) point is close to the centroid position of the segment at N point. And the segments whose determination result is “YES” are recognized as the same segment.

  Next, in step S04, a separation / fusion process for segment separation or fusion, which will be described later, is executed, and the series of processes ends.

Hereinafter, the separation and fusion process in step S04 described above will be described.
First, for example, in step S11 shown in FIG. 4, an appropriate segment is set as the first segment, and the reflection point having the latest calculated timing (or the earliest reflection point) among the reflection points constituting the first segment. Is defined as a first reflection point. For example, by determining whether there is another segment having a reflection point whose distance from the first reflection point is less than a second predetermined value, It is determined whether there are other segments to be merged around.
When the determination result is “NO”, the series of processes is terminated.
On the other hand, if this determination is “YES”, the flow proceeds to step S12.

In step S12, the other segment to be merged is set as the second segment, and the distance between the first reflection point of the first segment and each of the plurality of reflection points constituting the second segment (between the reflection points). Distance).
In step S13, the reflection point having the earliest calculated timing (or the latest reflection point) among the reflection points constituting the second segment is set as the second reflection point, and among the distances between the plurality of reflection points. Then, it is determined whether the distance between the reflection points between the first reflection point and the second reflection point is the shortest.
When the determination result is “NO”, the series of processes is terminated.
On the other hand, if the determination is “YES”, the flow proceeds to step S14.
When the first reflection point is the reflection point that is the latest calculated among the reflection points constituting the first segment, the second reflection point is calculated among the reflection points constituting the second segment. When the reflected timing is the earliest reflection point and the first reflection point is the reflection point with the earliest timing calculated among the reflection points constituting the first segment, the second reflection point is the second segment. The timing calculated in the reflection points constituting the point is the latest reflection point.

In step S14, a correlation value (for example, an inner product of the movement vectors) between the movement vector based on the relative speed of the center of gravity of the first segment and the movement vector based on the relative speed of the center of gravity of the second segment is calculated.
In step S15, it is determined whether or not the correlation value is greater than or equal to a predetermined threshold (for example, a third predetermined value).
When the determination result is “NO”, the series of processes is terminated.
On the other hand, if this determination is “YES”, the flow proceeds to step S16.

  In step S16, the first segment and the second segment have the first segment based on the longer recognition time (that is, the period during which the reflection point was acquired with the scanning of the radar device 15). And the second segment are merged and recognized as a single segment, and a series of processing is terminated.

  As described above, according to the vehicle object detection device 10 according to the present embodiment, the distance between the first reflection point constituting the first segment and the second reflection point constituting the second segment is less than the second predetermined value. And the correlation value between the relative speed of the first segment and the relative speed of the second segment (for example, the inner product of the movement vectors) is equal to or greater than a third predetermined value, the first segment and the second segment Are recognized as the same segment, the single object is recognized as a plurality of different objects even when the first segment and the second segment are formed from the reflection points for the single object. Can be prevented. It is also possible to prevent a plurality of different objects from being recognized without being separated.

It is a block diagram of the vehicle object detection apparatus which concerns on one Embodiment of this invention. It is a figure which shows an example of a segment. It is a flowchart which shows operation | movement of the vehicle object detection apparatus shown in FIG. It is a flowchart which shows the isolation | separation fusion process shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle object detection apparatus 15 Radar apparatus (transmission / reception means)
32 reflection point calculation unit (reflection point calculation means)
34 Segment setting section (segmentation means)
35 Center of gravity calculation unit (center of gravity calculation means)
36 Relative speed calculation unit (relative speed calculation means)

Claims (1)

Transmitting and receiving means for transmitting an electromagnetic wave over a predetermined angle around the vehicle at a predetermined time interval and receiving a reflected wave of the electromagnetic wave from an object existing around the vehicle;
A reflection point calculating means for calculating a reflection point when the electromagnetic wave transmitted by the transmitting / receiving means reflects on the surface of the object;
Segmenting means for recognizing that the reflection points having an interval between the reflection points for each electromagnetic wave less than a first predetermined value exist in the same segment;
Centroid calculating means for calculating the centroid of the segment;
A relative speed calculating means for calculating a relative speed between the vehicle and the object based on the center of gravity;
The segmenting means is configured such that an interval between a first reflection point constituting the first segment and a second reflection point constituting the second segment is less than a second predetermined value, and the relative speed of the first segment and the When the correlation value with the relative speed of the second segment is equal to or greater than a third predetermined value, the first segment and the second segment are recognized as the same segment ,
The reflection point calculation means calculates the reflection point having the latest timing among the reflection points that constitute the first segment as the first reflection point, and is calculated among the reflection points that constitute the second segment. The reflection point with the earliest timing is the second reflection point,
The segmenting means includes the first and second reflection points in the interval between the reflection points for each combination of the reflection points constituting the first segment and the reflection points constituting the second segment. An object detection apparatus for a vehicle , wherein the first segment and the second segment are recognized as the same segment when the interval between them is minimized .

Images