JP6805970B2 - Target information acquisition device - Google Patents

Description

The present invention relates to a target information acquisition device that acquires target information such as the width and length of a three-dimensional object (for example, another vehicle) existing around a vehicle (own vehicle).

Conventionally, a lane change support device that supports a steering operation (steering wheel operation) for changing lanes has been known (see, for example, Patent Document 1). The lane change support device detects a three-dimensional object (for example, another vehicle) existing around the vehicle by a plurality of radar sensors (for example, millimeter-wave radar and laser radar) provided in the vehicle, and the three-dimensional object is detected. Information such as "vertical position, horizontal position and relative vehicle speed" for the own vehicle and "width and length" of the three-dimensional object (hereinafter, also referred to as "target information") is acquired. Then, the lane change support device monitors whether or not the own vehicle is safe even if the vehicle changes lanes based on the acquired target information, and executes lane change support when it is determined that the vehicle is safe. Such a "target information acquisition device for acquiring target information of a three-dimensional object existing around the own vehicle" is not limited to the lane change support device, but is not limited to other driving support devices (for example, vehicle peripheral monitoring / alarm). It is also used for equipment).

JP-A-2009-274594

By the way, as is well known, a radar sensor emits a radar wave in a range having a predetermined angular width to the left and right with respect to the radiation center axis, and the reflection generated by the radar wave being reflected by a three-dimensional object. It receives a wave, recognizes a target based on the received reflected wave, and acquires target information. Therefore, depending on the type of the three-dimensional object and the relative positional relationship between the three-dimensional object and the own vehicle, the two radar sensors may recognize a plurality of sensor targets (reflection points) for the same three-dimensional object.

Therefore, when a plurality of sensor targets are detected, the target information acquisition device groups the sensor targets that are likely to detect the same three-dimensional object among the plurality of sensor targets. , May be configured to produce a fusion marker indicating that same three-dimensional object.

On the other hand, focusing on two specific radar sensors among the plurality of radar sensors, the two radar sensors have a part of the detection range of each three-dimensional object overlapped with each other (in other words, the overlap detection area is set. Often mounted on own vehicle (as it has) (see, for example, the gray colored area of FIG. 4). When two specific radar sensors have an overlap detection area, the radar wave radiation angles of each of the two radar sensors with respect to an arbitrary position in the overlap detection area are different from each other (for example, the point of FIG. 4). See radiation angle θ1 and radiation angle θ2 with respect to P). On the other hand, as is well known, the radar sensor has a characteristic that the detection accuracy of the sensor target information (particularly, the lateral position) decreases as the radiation angle θh of the radar wave increases (see FIG. 3).

Therefore, when all or a part of the three-dimensional object exists in the overlap detection region, the lateral sensor target information included in the plurality of sensor targets belonging to the fusion target generated for the three-dimensional object is included in the sensor target information. Sensor targets with low position detection accuracy may be included. As a result, in particular, when calculating the width of the three-dimensional object (width of the fusion target), depending on which of the plurality of sensor targets belonging to the fusion target is used, the lateral position of the sensor target is used. Large errors may occur.

The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is a target information acquisition device capable of more accurately acquiring "target information including the width of a three-dimensional object" by using a plurality of radar sensors (hereinafter, "the present invention". Also referred to as "equipment").

The apparatus of the present invention includes a plurality of radar sensors (16FC, 16FL, 16FR, 16RL and 16RR).
The plurality of radar sensors (16FC, 16FL, 16FR, 16RL and 16RR) each have a predetermined angular width (|) in the range around the own vehicle (SV) and to the left and right with respect to the radiation center axis (Cs). A radar wave is radiated in a range having α |), the reflection point of the radiated radar wave by a three-dimensional object is detected as a sensor target (Bn), and the vertical position (Xobj) of the detected sensor target with respect to the own vehicle. ), Horizontal position (Yobj) and relative speed (Vxobj, Vyobj) are acquired as sensor target information.

Further, the apparatus of the present invention
When a plurality of the sensor targets are detected, fusion indicating the same three-dimensional object by grouping the sensor targets that are likely to detect the same three-dimensional object among the plurality of sensor targets. Fusion target generation means (10, step 1120, step 1140, step 1150) for generating a target (FBn), and
The width (Wf) of the fusion target, which is one of the attribute values of the fusion target, is calculated based on the sensor target information of the sensor targets grouped so as to generate the fusion target. Fusion target information calculation means (10, step 1180),
To be equipped.

In addition, the plurality of radar sensors
A first region (AR) and a second radar, which include a first radar sensor (for example, 16RR) and a second radar sensor (for example, 16RL) and are regions in which the first radar sensor can detect the sensor target. The sensor is mounted on the own vehicle (SV) so as to have a region (ARL) that overlaps with a second region (AL) that is a region in which the sensor target can be detected.

However, in general, the radiation angles of the radar waves of each of the two radar sensors with respect to an arbitrary position in the overlap detection region are different from each other, so that the sensors are included in the sensor targets grouped to generate fusion targets. A sensor target having a high horizontal position detection accuracy and a sensor target having a low detection accuracy included in the target information may be included. Therefore, when the horizontal position with low detection accuracy is used to calculate the width of the fusion target, the calculated width may include a large error.

Therefore, at least one of the sensor targets grouped so as to generate the fusion target is a sensor target (first sensor target) detected by the first radar sensor (for example, 16RR). And, at least one of the sensor targets grouped so as to generate the fusion target is a sensor target (second sensor target) detected by the second radar sensor (for example, 16RL). )If it is,
The fusion target information calculation means
When the second sensor target (for example, BRL1 or BRL2) is located in a region closer to the first radar sensor (16RR) with respect to the reference axis (Qb) described later, the second sensor object. The width (Wf) of the fusion target is calculated using the horizontal position included in the sensor target information of the first sensor target (for example, BRR1 and BRR2) without using the sensor target information of the target. And
When the first sensor target (for example, BRR3, BRR4) is located in a region closer to the second radar sensor (16RL) with respect to the reference axis (Qb), the first sensor target The width (Wf) of the fusion target is calculated by using the horizontal position included in the sensor target information of the second sensor target (for example, BRL3, BRL4) without using the sensor target information of the above. ,
It is configured as follows.

When the second sensor target (for example, BRL1 and BRL2) is located in the region closer to the first radar sensor (16RR) with respect to the reference axis (Qb), the second radar sensor emission angle is the first. Since it is larger than the radar sensor radiation angle, the lateral position included in the sensor target information of the first sensor target (for example, BRR1 and BRR2) is more than the accuracy of the lateral position included in the sensor target information of the second sensor target. The accuracy of is higher. On the other hand, when the first sensor target (for example, BRR3, BRR4) is located in the region closer to the second radar sensor (16RL) with respect to the reference axis (Qb), the first radar sensor emits light. Since the angle is larger than the second radar sensor radiation angle, the sensor target information of the second sensor target (for example, BRL3, BRL4) is more important than the accuracy of the lateral position included in the sensor target information of the first sensor target. The accuracy of the included horizontal position is higher. Therefore, according to the apparatus of the present invention, the width (Wf) of the fusion target is calculated based on the more accurate horizontal position, so that the width of the fusion target can be calculated more accurately.

In the above description, in order to help the understanding of the present invention, the names and / or symbols used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the embodiment defined by the above name and / or reference numeral.

FIG. 1 is a schematic configuration diagram of a driving support device according to an embodiment of the present invention. FIG. 2 is a plan view of the own vehicle showing the arrangement position of the peripheral radar sensor shown in FIG. FIG. 3 is a schematic diagram showing the distribution of detection accuracy in the detection range of the radar sensor. FIG. 4 is a plan view showing the overlap detection region and the radiation angle of the two radar sensors. FIG. 5 is a plan view of the own vehicle and the road for explaining the lane keeping control. FIG. 6 is a diagram for explaining a method of calculating the target width and the target length. FIG. 7A is a plan view for explaining a reference example of a method of calculating the target width and the target length of the fusion target. FIG. 7B is a plan view for explaining a method of calculating the target width and the target length of the fusion target of the present implementation device. 8 (A), (B) and (C) are diagrams for explaining a grouping process for integrating sensor targets. 9 (A) and 9 (B) are diagrams for explaining a grouping process for integrating sensor targets. FIG. 10 is a diagram for explaining a grouping process for integrating sensor targets. FIG. 11 is a flowchart showing a routine executed by the CPU of the driving support ECU shown in FIG.

Hereinafter, the target information acquisition device according to the embodiment of the present invention will be described with reference to the drawings. This target information acquisition device is incorporated in a lane change support device (hereinafter, also referred to as "this implementation device") which is a part of a driving support control device (vehicle travel control device).

(Constitution)
As shown in FIG. 1, the present implementation device is applied to a vehicle (hereinafter, referred to as "own vehicle" to distinguish it from other vehicles), and is applied to a driving support ECU 10, an engine ECU 30, and a brake ECU 40. , Steering ECU 50, meter ECU 60 and display ECU 70. In the following, the driving support ECU 10 is also simply referred to as a “DS ECU”.

These ECUs are electric control units (Electric Control Units) including a microcomputer as a main part, and are connected to each other so as to be able to transmit and receive information via a CAN (Controller Area Network) (not shown). In the present specification, the microcomputer includes a CPU, ROM, RAM, non-volatile memory, interface I / F, and the like. The CPU realizes various functions by executing instructions (programs, routines) stored in ROM. Some or all of these ECUs may be integrated into one ECU.

The DSECU is connected to the sensors (including switches) listed below and is adapted to receive detection signals or output signals of those sensors. Each sensor may be connected to an ECU other than the DSECU. In that case, the DSECU receives their detection signal or output signal from the ECU to which the sensor is connected via CAN.

Accelerator pedal operation amount sensor 11 that detects the operation amount of the accelerator pedal 11a.
Brake pedal operation amount sensor 12 that detects the operation amount of the brake pedal 12a.
Steering angle sensor 13 that detects the steering angle θ of the steering wheel SW.
A steering torque sensor 14 that detects a steering torque Tra applied to the steering shaft US of the own vehicle by operating the steering handle SW.
A vehicle speed sensor 15 that detects the traveling speed (vehicle speed) of the own vehicle and detects the vehicle speed V, which is the speed in the front-rear direction (that is, the vertical speed) of the own vehicle.
Peripheral sensor 16 including peripheral radar sensor 16a and camera sensor 16b.
Operation switch 17.
A yaw rate sensor 18 that detects the yaw rate YRt of the own vehicle SV.
A front-rear acceleration sensor 19 that detects an acceleration Gx in the front-rear direction of the own vehicle SV.
The lateral acceleration sensor 20 that detects the acceleration Gy in the lateral (vehicle width) direction of the own vehicle SV (the direction orthogonal to the central axis of the own vehicle SV).

As shown in FIG. 2, the peripheral radar sensor 16a includes a central front peripheral sensor 16FC, a right front peripheral sensor 16FR, a left front peripheral sensor 16FL, a right rear peripheral sensor 16RR, and a left rear peripheral sensor 16RL. These peripheral sensors have substantially the same configuration and are referred to as "peripheral radar sensors 16a" when it is not necessary to distinguish them individually.

The peripheral radar sensor 16a includes a radar transmission / reception unit and a signal processing unit (not shown). As shown in FIG. 3, the radar transmission / reception unit transmits radar waves (hereinafter, referred to as “millimeter waves”), which are radio waves in the millimeter wave band, to the left and right with respect to the radiation center axis Cs. It radiates in the range with | α | °). Further, the peripheral radar sensor 16a receives millimeter waves (that is, reflected waves) reflected by three-dimensional objects (for example, other vehicles, pedestrians, bicycles, buildings, etc.) existing in the radiation range. A point of a three-dimensional object that reflects millimeter waves is also called a "reflection point".

The signal processing unit is based on the phase difference between the transmitted millimeter wave and the received reflected wave, their frequency difference, the attenuation level of the reflected wave, the time from the transmission of the millimeter wave to the reception of the reflected wave, and the like. The distance between the own vehicle SV and the reflection point of the three-dimensional object, the relative speed between the own vehicle SV and the reflection point of the three-dimensional object, and the orientation of the reflection point of the three-dimensional object with respect to the own vehicle SV are detected. The reflection point of this three-dimensional object is regarded as a target and is also called a "sensor target".

The center front peripheral sensor 16FC is provided in the front center portion of the vehicle body and detects a sensor target existing in the front region of the own vehicle SV.
The right front peripheral sensor 16FR is provided at the right front corner of the vehicle body, and mainly detects a sensor target existing in the right front region of the own vehicle SV. A part of the sensor target detection area of the right front peripheral sensor 16FR overlaps with a part of the sensor target detection area of the central front peripheral sensor 16FC. That is, the right front peripheral sensor 16FR and the central front peripheral sensor 16FC have an overlap detection region.
The left front peripheral sensor 16FL is provided at the left front corner of the vehicle body, and mainly detects a sensor target existing in the left front region of the own vehicle SV. A part of the sensor target detection area of the left front peripheral sensor 16FL overlaps with a part of the sensor target detection area of the central front peripheral sensor 16FC. That is, the left front peripheral sensor 16FL and the central front peripheral sensor 16FC have an overlap detection region.
The right rear peripheral sensor 16RR is provided at the right rear corner of the vehicle body, and as shown in FIG. 4, mainly detects a sensor target existing in the right rear region AR of the own vehicle SV.
The left rear peripheral sensor 16RL is provided at the left rear corner of the vehicle body, and as shown in FIG. 4, mainly detects a sensor target existing in the left rear region AL of the own vehicle SV.
A part of the sensor target detection area of the left rear peripheral sensor 16RL overlaps with a part of the sensor target detection area of the right rear peripheral sensor 16RR. That is, the left front peripheral sensor 16FL and the right rear peripheral sensor 16RR have an overlap detection region (region ARL colored in gray in FIG. 4).
For example, the peripheral radar sensor 16a detects a sensor target whose distance from the own vehicle SV is within a range of about 100 meters. The peripheral radar sensor 16a may be a radar sensor that uses radio waves (radar waves) in a frequency band other than the millimeter wave band.

As shown in FIG. 2, the DSECU defines the XY coordinates. The X-axis is a coordinate axis that extends along the front-rear direction of the own vehicle SV so as to pass through the center position in the width direction of the front end portion of the own vehicle SV and has the front as a positive value. The Y-axis is a coordinate axis that is orthogonal to the X-axis and has a positive value in the left direction of the own vehicle SV. The origin of the X-axis and the origin of the Y-axis are the center positions in the width direction of the front end portion of the own vehicle SV.

Based on the above-mentioned reflection point information, the peripheral radar sensor 16a transmits the following "information about the sensor target" to the DSPE every time a predetermined time (calculation cycle) elapses. The information about the sensor target is hereinafter referred to as "sensor target information".

-X coordinate position (Xobj) of the sensor target. That is, the signed distance between the own vehicle SV and the sensor target in the X-axis direction. The X coordinate position Xobj is also referred to as a vertical distance Xobj or a vertical position Xobj.
-Y coordinate position (Yobj) of the sensor target. That is, the signed distance between the own vehicle SV and the sensor target in the Y-axis direction. The Y coordinate position Yobj is also referred to as a horizontal position Yobj.
-Velocity (that is, vertical relative velocity) Vxobj in the X-axis direction with respect to the own vehicle SV of the sensor target. The vertical absolute speed Vaxobj is a value obtained by adding the vehicle speed V of the own vehicle SV to the vertical relative speed Vxobj.
-Velocity in the Y-axis direction (that is, lateral relative velocity) Vyobj of the sensor target with respect to the own vehicle SV. The lateral absolute velocity Vyobj is set to a value equal to the lateral relative velocity Vyobj.
-Information for each sensor target (sensor target ID) for identifying (identifying) the sensor target

By the way, one three-dimensional object may have two or more reflection points. Therefore, each of the peripheral radar sensors 16a may detect a plurality of sensor targets for one three-dimensional object. Further, two or more peripheral radar sensors 16a may detect a plurality of sensor targets for one three-dimensional object.

Therefore, the DSECU groups (integrates, fuses) a plurality of sensor targets that are likely to detect one three-dimensional object, thereby indicating one target indicated by the plurality of sensor targets (hereinafter, "fusion"). It is called a "target").

Further, the DSECU acquires the "attribute value (information about the attribute value) of the fusion target" as described later. The information about the attribute value of the fusion target is referred to as "fusion target information or fusion target attribute value" and includes the information described below.

-X coordinate position (Xf) of the fusion target. That is, the signed distance between the own vehicle SV and the fusion target in the X-axis direction. In this example, the X coordinate position Xf is the X coordinate position of the center point of the fusion target.
-Y coordinate position (Yf) of the fusion target. That is, the signed distance between the own vehicle SV and the fusion target in the Y-axis direction. In this example, the Y coordinate position Yf is the Y coordinate position of the center point of the fusion target.
-Velocity (that is, vertical relative velocity) Vxf in the X-axis direction with respect to the own vehicle SV of the fusion target.
-Velocity (that is, lateral relative velocity) Vyf in the Y-axis direction with respect to the own vehicle SV of the fusion target.
-Length of fusion target Lf (length of fusion target in the X-axis direction).
-Width of fusion target Wf (length of fusion target in the Y-axis direction).
-Information for each fusion target (fusion target ID) for identifying (identifying) the fusion target.

The camera sensor 16b includes a camera unit that is a stereo camera, and a lane recognition unit that analyzes image data obtained by photographing by the camera unit and recognizes a white line on a road. The camera sensor 16b (camera unit) captures the scenery in front of the own vehicle SV. The camera sensor 16b (lane recognition unit) analyzes the image data of the image processing area having a predetermined angle range (range extending in front of the own vehicle SV), and a white line (section) formed on the road in front of the own vehicle SV. Line) is recognized (detected). The camera sensor 16b transmits information about the recognized white line to the DSP.

Based on the information supplied from the camera sensor 16b, the DSECU has left and right white lines WL in the lane in which the own vehicle SV is traveling (hereinafter, also referred to as “own lane”), as shown in FIG. The lane center line CL, which is the center position in the width direction, is specified. This lane center line CL is used as a target traveling line in lane keeping support control described later. Further, the DESCU calculates the curvature Cu of the curve of the lane center line CL.

In addition, the DESCU calculates the position and orientation of the own vehicle SV in the lane partitioned by the left white line and the right white line. For example, as shown in FIG. 5, the DESCU calculates the signed distance Dy in the road width direction between the reference point P (for example, the position of the center of gravity) of the own vehicle SV and the lane center line CL. The magnitude of the signed distance Dy indicates the distance at which the own vehicle SV deviates from the lane center line CL in the road width direction. This signed distance Dy is also referred to hereinafter as "lateral deviation Dy".

The DESCU calculates the angle θy formed by the direction of the lane center line CL and the direction in which the own vehicle SV is facing (the direction of the front-rear axis of the own vehicle SV). This angle θy is also referred to hereinafter as “yaw angle θy”. The yaw angle θy becomes a positive value when the direction in which the own vehicle SV is facing is clockwise with respect to the direction of the lane center line CL, and the direction in which the own vehicle SV is facing is in the direction of the lane center line CL. On the other hand, it is defined to have a negative value when it is on the counterclockwise side. Hereinafter, the information (Cu, Dy, θy) representing the curvature Cu, the lateral deviation Dy, and the yaw angle θy may be referred to as “lane-related vehicle information”.

The camera sensor 16b supplies the DSECU with information about the types of the left white line and the right white line of the own lane (for example, whether they are solid lines or broken lines) and the shape of the white lines. Further, the camera sensor 16b also supplies the DSECU with the types of the left white line and the right white line of the lane adjacent to the own lane, the shape of the white line, and the like. That is, the camera sensor 16b also supplies "information about the white line" to the DSECU. If the white line is a solid line, vehicles are prohibited from changing lanes across the white line. On the other hand, if the white line is a broken line (white line formed intermittently at regular intervals), the vehicle is allowed to change lanes across the white line. Lane-related vehicle information (Cu, Dy, θy) and information on white lines may be referred to as "lane information".

The operation switch 17 is an operator operated by the driver to select whether or not to execute each of the "lane change support control, lane keeping control, and follow-up inter-vehicle distance control" described later. is there. Therefore, the operation switch 17 outputs a signal indicating whether or not the execution of each of the above controls is selected according to the operation of the driver.

The engine ECU 30 is connected to the engine actuator 31. The engine actuator 31 includes a throttle valve actuator that changes the opening degree of the throttle valve for adjusting the intake air amount of the internal combustion engine. The engine ECU 30 can control the driving force of the own vehicle SV and change the acceleration state (acceleration) by changing the torque generated by the internal combustion engine 32 by driving the engine actuator 31.

The brake ECU 40 is connected to the brake actuator 41. The brake actuator 41 adjusts the hydraulic pressure supplied to the wheel cylinder built in the brake caliper 42b of the friction brake mechanism 42 in response to an instruction from the brake ECU 40, and the brake pad is pressed against the brake disc 42a by the hydraulic pressure to cause friction braking force. To generate. Therefore, the brake ECU 40 can control the braking force of the own vehicle SV and change the acceleration state (deceleration) by controlling the brake actuator 41.

The steering ECU 50 is a well-known control device for an electric power steering system, and is connected to a motor driver 51. The motor driver 51 is connected to the steering motor 52. The steering motor 52 is incorporated in the "steering mechanism including the steering wheel, the steering shaft connected to the steering handle, the steering gear mechanism, and the like" of the vehicle. The steering motor 52 generates torque by the electric power supplied from the motor driver 51, and the steering assist torque can be applied or the left and right steering wheels can be steered by this torque. That is, the steering motor 52 can change the steering angle (steering angle of the steering wheel) of the own vehicle SV.

The steering ECU 50 is connected to the turn signal lever switch 53. The blinker lever switch 53 is a detection switch that detects an operating position of the blinker lever operated by the driver to operate (blink) the turn signal lamp 61.

The blinker lever is provided on the steering column. The winker lever has two positions: a first stage position that is rotated by a predetermined angle in the clockwise operation direction from the initial position, and a second stage position that is rotated in a clockwise operation direction by a predetermined rotation angle from the first stage position. It can be operated in one position. The turn signal lever maintains that position as long as it is maintained in the first stage position in the clockwise operation direction by the driver, but when the driver releases the turn signal lever, it automatically returns to the initial position. There is. The blinker lever switch 53 outputs a signal to the steering ECU 50 indicating that the blinker lever is maintained in the first stage position in the clockwise operation direction when the blinker lever is in the first stage position in the clockwise operation direction.

Similarly, the winker lever has a first stage position rotated counterclockwise from the initial position by a predetermined angle and a second stage position rotated counterclockwise by a predetermined rotation angle from the first stage position. It can be operated in two positions,, and. The blinker lever maintains its position as long as it is maintained in the first stage position in the counterclockwise operation direction by the driver, but when the driver releases the blinker lever, it automatically returns to the initial position. There is. The blinker lever switch 53 outputs a signal to the steering ECU 50 indicating that the blinker lever is maintained in the first stage position in the counterclockwise operation direction when the blinker lever is in the first stage position in the counterclockwise operation direction. It should be noted that such a blinker lever is disclosed in, for example, Japanese Patent Application Laid-Open No. 2005-138647.

Based on the signal from the blinker lever switch 53, the DSECU measures the duration of the blinker lever held in the first stage position in the clockwise operation direction. Further, when the DSPE determines that the measured duration is equal to or longer than the preset support request confirmation time (for example, 0.8 seconds), the lane change support is provided for the driver to change lanes to the right lane. It is determined that a request to receive the request (hereinafter, also referred to as a "lane change support request") has been issued.

Further, the DSECU measures the duration of the blinker lever held in the first stage position in the counterclockwise operation direction based on the signal from the blinker lever switch 53. Further, when the DSPE determines that the measured duration is equal to or longer than the preset support request confirmation time, it determines that the driver has issued a lane change support request in order to change the lane to the left lane. It has become like.

The meter ECU 60 is connected to the left and right turn signal lamps 61 (turn signal lamps) and the information display 62.

The meter ECU 60 blinks the left or right turn signal lamp 61 in response to a signal from the blinker lever switch 53, an instruction from the DSECU, or the like via a blinker drive circuit (not shown). For example, the meter ECU 60 blinks the left turn signal lamp 61 when the blinker lever switch 53 outputs a signal indicating that the blinker lever is maintained at the first stage position in the counterclockwise operation direction. Further, the meter ECU 60 blinks the right turn signal lamp 61 when the blinker lever switch 53 outputs a signal indicating that the blinker lever is maintained at the first stage position in the clockwise operation direction.

The information display 62 is a multi-information display provided in front of the driver's seat. The information display 62 displays various information in addition to measured values such as vehicle speed and engine speed. For example, when the meter ECU 60 receives a display command from the DSECU according to the driving support state, the meter ECU 60 displays the screen designated by the display command on the information display 62.

The display ECU 70 is connected to the buzzer 71 and the display 72. The display ECU 70 can alert the driver by sounding the buzzer 71 or displaying a caution screen on the display 72 in response to an instruction from the DSECU.

(Overview of basic driving support control)
The DSECU is designed to execute follow-up inter-vehicle distance control, lane keeping control, and lane change support control. The lane keeping control is executed only when the following inter-vehicle distance control is executed. The lane change support control is executed only when the lane keeping control is executed.

The following vehicle-to-vehicle distance control follows the own vehicle SV while maintaining the distance between the preceding vehicle (that is, the vehicle to be followed) and the own vehicle SV traveling in front of the own vehicle SV at a predetermined distance. (For example, see Japanese Patent Application Laid-Open No. 2014-148293, Japanese Patent Application Laid-Open No. 2006-315491, Japanese Patent No. 4172434, Japanese Patent No. 4929777, and the like).

The lane keeping control is the steering torque so that the position of the own vehicle SV is maintained near the target driving line (for example, the center line of the own lane) in the "lane (own lane) in which the own vehicle SV is traveling". Is applied to the steering mechanism to change the steering angle of the own vehicle SV, thereby supporting the steering operation of the driver (for example, JP-A-2008-195402, JP-A-2009-190464, Japanese Patent Application Laid-Open No. 2010-6279, Japanese Patent No. 4349210, etc.).

The lane change support control applies steering torque to the steering mechanism so that the own vehicle SV moves from the own lane (former lane) to the "lane adjacent to the original lane (target adjacent lane) desired by the driver". By doing so, the steering angle of the own vehicle SV is changed, thereby supporting the driver's steering operation (steering operation for changing lanes) (for example, Japanese Patent Application Laid-Open No. 2016-207060 and Japanese Patent Application Laid-Open No. 2016-207060). See Kai 2017-74823, et al.).

<Outline of operation>
By the way, when executing the lane change support control, the DSECU determines whether or not the own vehicle SV can safely change lanes, so that the position and relative speed of the three-dimensional object existing around the own vehicle SV And it is necessary to acquire three-dimensional object information about the size (length, width) and the like. The DESCU recognizes this three-dimensional object by generating the above-mentioned "fusion target", and the above-mentioned "fusion target information (for example," length, width, coordinate position and relative velocity "of the fusion target". ) ”Is acquired as three-dimensional object information. The outline of the operation of the present implementation device when acquiring the fusion target information will be described below. The method of generating / updating the fusion target will be described later.

Every time a predetermined calculation cycle (Δt) elapses, the DSPE groups (integrates) the sensor targets detected by the peripheral radar sensor 16a by a grouping process described later to generate or update the fusion target. Further, the DSPE uses the fusion target information of the generated or updated fusion target as the sensor object of the sensor target belonging to the fusion target (that is, the sensor target grouped so as to generate the fusion target). Generate based on the target information.

However, not all sensor targets have accurate sensor target information. That is, when the sensor target is a target erroneously detected by the peripheral radar sensor 16a (so-called ghost target), or when the sensor target information is erroneous due to the influence of noise, etc. , The accuracy of the sensor target information is reduced.

Therefore, the DSPE (or the peripheral radar sensor 16a) calculates "information indicating the length of the period during which the sensor target continues to be detected" called "AGE" for the sensor target. Specifically, the DSPE sets the value of "AGE" of the sensor target detected for the first time to "0", and each time one calculation cycle Δt elapses, the sensor object detected at the time of the previous calculation. When the same sensor target as the target (sensor target having the same identification information) is detected, the value of "AGE" for the sensor target is incremented (+1). When the sensor target is detected by ghost or noise, it is unlikely that the sensor target will continue to be detected as the same target for a long period of time, so that the AGE of the sensor target does not increase.

Further, the DSECU recognizes a sensor target having a value of "AGE" equal to or higher than a predetermined threshold value as a "high AGE sensor target". The DESCU recognizes a sensor target whose "AGE" value is smaller than a predetermined threshold value as a "low AGE sensor target".

Then, the DESCU has at least the length Lf of the fusion target (hereinafter, also referred to as "target length Lf") and the width Wf of the fusion target (hereinafter, "target width Wf") in the fusion target information. ”) And the position (Xf, Yf) are calculated using the sensor target information of the“ high AGE sensor target among the sensor targets belonging to the fusion target ”.

In the example shown in FIG. 6, a fusion target FBn in which the sensor target Bn1, the sensor target Bn2, and the sensor target Bn3 are grouped (integrated) is generated. Both the sensor target Bn1 and the sensor target Bn2 are high AGE sensor targets, and the sensor target Bn3 is a low AGE sensor target.

Therefore, in this case, the DSPE sets the "target length Lf, target width Wf, and coordinate position (Xf, Yf)" of the fusion target FBn to the high AGE sensor target "sensor target Bn1 and high AGE". The calculation is performed using the sensor target Bn2.

More specifically, the DSPE calculates the magnitude of the difference between the maximum vertical position Xmaxh and the minimum vertical position Xminh (= | Xmaxh−Xminh |) as the target length Lf. Here, the maximum vertical position Xmaxh is "the maximum value in the X coordinate position Xobj of the high AGE target belonging to the fusion target FBn", and in the example of FIG. 6, it is the X coordinate position Xobj of the sensor target Bn2. .. The minimum vertical position Xminh is "the minimum value in the X coordinate position Xobj of the high AGE target belonging to the fusion target FBn", and in the example of FIG. 6, it is the X coordinate position Xobj of the sensor target Bn1.

Similarly, it is conceivable to calculate the magnitude of the difference between the maximum lateral position Ymaxh and the minimum lateral position Yminh (= | Ymaxh−Yminh |) as the width Wf of the fusion target FBn. Here, the maximum horizontal position Ymaxh is "the maximum value in the Y coordinate position Yobj of the high AGE target belonging to the fusion target FBn", and in the example of FIG. 6, it is the Y coordinate position Yobj of the sensor target Bn2. .. The minimum lateral position Yminh is "the minimum value in the Y coordinate position Yobj of the high AGE target belonging to the fusion target FBn", and in the example of FIG. 6, it is the Y coordinate position Yobj of the sensor target Bn1.

However, among the high AGE sensor targets, it is included in the sensor target information depending on the position of the sensor target with respect to the own vehicle SV (in other words, which peripheral radar sensor 16a is detecting the sensor target). The accuracy of the position information, especially the accuracy of the horizontal position (Y coordinate position Yobj), is lowered. More specifically, as shown in FIG. 3, the accuracy of the position (particularly the lateral position) included in the sensor target information acquired by the peripheral radar sensor 16a increases as the radiation angle θh of the radar wave increases. Get worse. Here, the radiation angle θh is an angle (magnitude) formed by the radiation center axis Cs and the straight line connecting the sensor target SB and the peripheral radar sensor 16a (radar wave radiation position). Therefore, as described above, when the DSECU finds the maximum lateral position Ymaxh and the minimum lateral position Yminh and calculates the magnitude of the difference between them (= | Ymaxh-Yminh |) as the width Wf of the fusion target FBn, the width is calculated. Wf may be significantly different from the true width of the three-dimensional object.

Hereinafter, a specific example in which the accuracy of the width Wf is lowered in this way and a method for calculating the width Wf adopted by the DSPE to deal with the decrease will be described. In the following, when there is a sensor target detected by two or more peripheral radar sensors 16a among the sensor targets belonging to the fusion target FBn, the fusion target is also referred to as a "mixed fusion target". To.

In the example shown in FIG. 7A, a mixed fusion target FBa1 in which the sensor target BRR1, the sensor target BRR2, the sensor target BRL1 and the sensor target BRL2 are grouped (integrated) is generated. The sensor target BRR1 and the sensor target BRR2 are sensor targets detected by the right rear peripheral sensor 16RR. The sensor target BRL1 and the sensor target BRL2 are sensor targets detected by the left rear peripheral sensor 16RL. The sensor target BRR1, the sensor target BRR2, the sensor target BRL1, and the sensor target BRL2 are all high AGE targets.

Here, the target width Wa1 of the mixed fusion target FBa1 is set to the maximum horizontal position Ymaxh (horizontal position of the sensor target BRL2) and the minimum horizontal position Yminh (sensor target) among the high AGE targets belonging to the fusion target FBa1. When the magnitude of the difference (= | Ymaxh-Yminh |) of the BRR2 lateral position is calculated, there is a high possibility that the target width Wa1 will be significantly different from the width of the actual three-dimensional object. This is because the sensor target BRL2 is detected by the left rear peripheral sensor 16RL and the radiation angle of the radar wave of the left rear peripheral sensor 16RL with respect to the sensor target BRL2 is large, so that the sensor target information of the sensor target BRL2 This is because the accuracy of the horizontal position (Y coordinate position Yobj) included in is not good.

By the way, the reference axis Qb is the radiation angle of the radar wave of the right rear peripheral sensor 16RR (first radar sensor radiation angle) θ1 (see FIG. 4) and the radiation angle of the radar wave of the left rear peripheral sensor 16RL (second). Radar sensor radiation angle) θ2 (see FIG. 4) and a straight line connecting points that are equal to each other. Therefore, when a target located at an arbitrary point on the reference axis Qb is detected by the right rear peripheral sensor 16RR and when detected by the left rear peripheral sensor 16RL, the accuracy of the lateral position of the sensor target information is high. It is virtually the same.

On the other hand, when a mixed fusion target is generated on the side closer to the right rear peripheral sensor 16RR with respect to the reference axis Qb (the region on the right side of the reference axis Qb in FIGS. 7A and 7B), the mixed fusion target is generated. The horizontal position included in the sensor target information of the "sensor target detected by the right rear peripheral sensor 16RR" belonging to the mixed fusion target is the sensor detected by the "left rear peripheral sensor 16RL" belonging to the mixed fusion target. The accuracy is higher than the horizontal position included in the sensor target information of "Target". This is because the radiation angle θ1 of the first radar sensor is smaller than the radiation angle θ2 of the second radar sensor.

Similarly, when a mixed fusion target is generated on the side closer to the left rear peripheral sensor 16RL with respect to the reference axis Qb (the region on the left side of the reference axis Qb in FIGS. 7A and 7B), the mixture is mixed. The horizontal position included in the sensor target information of the "sensor target detected by the left rear peripheral sensor 16RR" belonging to the fusion target is the sensor object detected by the right rear peripheral sensor 16RR belonging to the mixed fusion target. The accuracy is higher than the horizontal position included in the sensor target information of the "mark". This is because the second radar sensor radiation angle θ2 is smaller than the first radar sensor radiation angle θ1.

From the above viewpoint, when the mixed fusion target is generated, the DSECU has selected the high AGE sensor target belonging to the mixed fusion target in order to accurately calculate the width Wf of the mixed fusion target. The sensor target that is likely to indicate a highly accurate lateral position is specified (extracted) as follows. This specified (extracted) sensor target is also referred to as a "high-precision, high-AGE sensor target".

Among the high AGE sensor targets belonging to the mixed fusion target, the DSECU refers to the high AGE sensor target detected by the peripheral radar sensor on the side closer to the reference axis Qb as the "high-precision high AGE sensor target". The target width Wf of the mixed fusion target FBn is calculated by using the horizontal position included in the sensor target information of the extracted high-precision and high-precision sensor target. In other words, the DSPE widths the sensor target information of the high AGE sensor target detected by the peripheral radar sensor on the side far from the reference axis Qb among the high AGE sensor targets belonging to the mixed fusion target. Not used for Wf calculation.

For example, in the example shown in FIG. 7B, the “sensor target BRR1 and sensor target BRR2” detected by the right rear peripheral sensor 16RR and the “sensor target BRL1” detected by the left rear peripheral sensor 16RL. And the sensor target BRL2 ”are grouped (integrated) to generate the mixed fusion target FBa1. Further, the "sensor target BRR3 and the sensor target BRR4" detected by the right rear peripheral sensor 16RR and the "sensor target BRL3 and the sensor target BRL4" detected by the left rear peripheral sensor 16RL are grouped (integrated). ), The mixed fusion target FBa2 is generated. It is assumed that all of these sensor targets are high AGE sensor targets.

In this case, focusing on the mixed fusion target FBa1, the peripheral radar sensor on the side closer to the reference axis Qb is the right rear peripheral sensor 16RR, so that the sensor target BRR1 and the sensor target BRR2 are high-precision and high-AGE sensors. It is extracted as a marker.

Then, when there are two or more high-precision high-precision AGE sensor targets extracted, the DSPE sets the maximum value in the Y-coordinate position Yobj of the extracted high-precision high-AGE sensor target to the maximum horizontal position Ymaxh (sensor target). It is determined as the Y coordinate position Yobj of BRR1), and the minimum value in the Y coordinate position Yobj of the extracted high-precision high AGE sensor target is determined as the minimum horizontal position Yminh (Y coordinate position Yobj of the sensor target BRR2). .. Further, the DSPE calculates the magnitude of the difference between the maximum horizontal position Ymaxh and the minimum horizontal position Yminh (= | maximum horizontal position Ymaxh − minimum horizontal position Yminh |), and uses this as the target width of the mixed fusion target (= | Let it be Wa1).

On the other hand, focusing on the mixed fusion target FBa2, since the peripheral radar sensor on the side closer to the reference axis Qb is the left rear peripheral sensor 16RL, the sensor target BRL3 and the sensor target BRL4 are high-precision and high-AGE sensor targets. Is extracted as.

Then, the DESCU adopts the Y coordinate position Yobj of the sensor target BRL4 as the maximum horizontal position Ymaxh and the Y coordinate position Yobj of the sensor target BRL3 as the minimum horizontal position Yminh by the above-mentioned method. Further, the DSPE calculates the magnitude of the difference between the maximum horizontal position Ymaxh and the minimum horizontal position Yminh (= | maximum horizontal position Ymaxh − minimum horizontal position Yminh |), and uses this as the target width of the mixed fusion target (= | Wa2).

As described above, the DSPE selects the maximum value of the X coordinate position Xobj of all the high AGE targets belonging to the mixed fusion target FBa1 (= the X coordinate position Xobj of the sensor target BRR1) as the maximum vertical position Xmaxh. Then, the minimum value of the X coordinate position Xobj of all the high AGE targets belonging to the mixed fusion target FBa1 (= X coordinate position Xobj of the sensor target BRL2) is selected as the minimum vertical position Xminh, and the magnitude of the difference between them is selected. (= | Xmaxh-Xminh |) is calculated as the target length La1 of the mixed fusion target FBa1. The same applies to the target length La2 of the mixed fusion target FBa2.

Further, the DSPE includes the X coordinate position Xobj of the sensor target selected as the sensor target indicating the maximum vertical position Xmaxh and the X coordinate position Xobj of the sensor target selected as the sensor target indicating the minimum vertical position Xminh. , Is calculated as the X coordinate position Xfn of the fusion target FBn (n = a1, a2). Similarly, the DESCU has a Y coordinate position Yobj of the sensor target selected as the sensor target indicating the maximum lateral position Ymaxh and a Y coordinate position Yobj of the sensor target selected as the sensor target indicating the minimum horizontal position Yminh. And, the center position of is calculated as the Y coordinate position Yfn of the fusion target FBn. In addition, the DSPE uses the "mean value of vertical relative velocity and the average value of horizontal relative velocity" of the high AGE sensor target belonging to the fusion target FBn as the "vertical relative velocity Vxfn and lateral relative velocity" of the fusion target FBn. Each calculation is performed as "Vyfn".

In the example shown in FIG. 7B, there were two or more high-precision high AGE targets selected for each mixed fusion target, but the high-precision high AGE selected for the mixed fusion target. When there is only one target, the DSPE sets the target width Wf of the fusion target to a predetermined fixed width W, and sets the target length Lf of the fusion target to a predetermined fixed length L. Set to. Further, the "XY coordinate position, vertical relative velocity and horizontal relative velocity" of the one selected high-precision high AGE target, the "XY coordinate position, vertical relative velocity Vxfn" of the fusion target FBn and It is set as "horizontal relative velocity Vyfn".

Further, the DESCU is an estimated target if there is no high AGE sensor target among the sensor targets belonging to the mixed fusion target and the fusion target is generated based on the estimated target described later. "XY coordinate position, target width, length, vertical relative velocity and horizontal relative velocity" of "XY coordinate position, target width Wf, target length Lf, vertical relative" of mixed fusion target Set as "speed and lateral relative velocity" respectively.

Further, the DESCU is predetermined when there is no high AGE sensor target among the sensor targets belonging to the mixed fusion target and the mixed fusion target is not generated based on the estimated target described later. “Fixed width and length” are set as “target width Wf and target length Lf” of the mixed fusion target, respectively. Further, the "XY coordinate position, vertical relative velocity and horizontal relative velocity" of the sensor target having the largest AGE among the sensor targets belonging to the mixed fusion target are set to the "XY coordinates" of the mixed fusion target. Set as "position, vertical relative velocity and horizontal relative velocity" respectively.

Further, when the fusion target is not a mixed fusion target, if there are two or more high AGE sensor targets in the sensor targets belonging to the fusion target, the DSECU can be obtained from the sensor target information of those high AGE sensor targets. The maximum vertical position Xmaxh, the minimum vertical position Xminh, the maximum horizontal position Ymaxh, and the minimum horizontal position Yminh are selected, and the target width Wf, the target length Lf, and the coordinate positions (Xf, Yf) are determined by the method described above. In addition, the DSPE uses the "mean value of vertical relative velocity and the average value of horizontal relative velocity" of the high AGE sensor target belonging to the fusion target FBn as the "vertical relative velocity Vxfn and lateral relative velocity" of the fusion target FBn. Each calculation is performed as "Vyfn". On the other hand, if the fusion target is not a mixed fusion target and the number of high AGE sensor targets is one or less, the DESCU has a fusion target that is a mixed fusion target and has one or less high-precision high AGE target. The target width Wf, the target length Lf, the coordinate positions (Xf, Yf), and the relative velocity are determined in the same manner as in the case of.

(How to generate / update fusion targets)
Next, a method of generating / updating the fusion target executed by the DSPE will be described.

The DSPE acquires sensor target information from the peripheral radar sensor 16a every time the predetermined time (calculation cycle) Δt elapses. Further, the DSECU performs a grouping process described later to group (integrate, fuse) "a plurality of sensor targets that are likely to be obtained from one three-dimensional object n", thereby forming the one three-dimensional object n. Generates a fusion target FBn corresponding to. Hereinafter, the "grouping process" will be described in detail with reference to the examples shown in FIGS. 8A and 8B.

Now, as shown in FIG. 8A, it is assumed that the sensor targets B0, B1 and B2 are detected. In this example, the sensor target B0 is a sensor target detected by the right front peripheral sensor 16FR, and the sensor target B1 and the sensor target B2 are sensor targets detected by the central front peripheral sensor 16FC. Furthermore, in this example, no fusion target has been generated so far (in other words, at the time of the previous calculation).

As described above, when the fusion target FBn is not generated at the start of the current calculation, the DSPE performs the grouping process for generating the new fusion target FBn as described below. This grouping process is called "new grouping process".

First, the DSPE selects any one sensor target (for example, sensor target B0) as the grouping reference target Bs from the plurality of sensor targets (for example, sensor targets B0 to B2). Next, the DESCU has "another sensor target Bn (for example, sensor target Bn, n = 1, 2) that is a grouping candidate" with respect to the grouping reference target Bs (for example, sensor target B0). , It is determined whether or not both of the following conditions (condition G1) and (condition G2) are satisfied. When the sensor target Bn of the grouping candidate satisfies both the following conditions (condition G1) and (condition G2), it is determined that the sensor target Bn satisfies the grouping condition.

(Condition G1) Condition using position as a criterion as shown in the figure on the left side of FIG. 8 (B).
The absolute value (= | XBn-XBs |) of the difference between the "X coordinate position Xobj (= XBn) of the sensor target Bn of the grouping candidate" and the "X coordinate position Xobj (= XBs) of the grouping reference target Bs" is The difference between the predetermined threshold vertical distance Xth or less and the "Y coordinate position Yobj (= YBn) of the grouping candidate sensor target Bn" and the "Y coordinate position Yobj (= YBs) of the grouping reference target Bs". The absolute value (= | YBn-YBs |) is equal to or less than the predetermined threshold lateral distance Yth.
Here, the threshold vertical distance Xth is, for example, "target length L0 × 0.5 + predetermined value α". The threshold lateral distance Yth is “target width W0 × 0.5 + predetermined value β”. Arbitrary fixed values suitable for determination are used for the target length L0 and the target width W0. For example, the target length L0 is set to the standard length of the motorcycle, and the target width W0 is set to the standard width of the motorcycle.

(Condition G2) Condition using speed as a criterion as shown in the figure on the right side of FIG. 8 (B).
The absolute value (= | VxBn-VxBs |) of the difference between the "vertical relative velocity Vxobj (= VxBn) of the grouping candidate sensor target Bn" and the "vertical relative velocity Vxobj (= VxBs) of the grouping reference target Bs" is , A predetermined threshold vertical velocity difference Vxth or less, and "horizontal relative velocity Vyobj (= VyBn) of the grouping candidate sensor target Bn" and "horizontal relative velocity Vyobj (= VyBs) of the grouping reference target Bs" The absolute value of the difference (= | VyBn-VyBs |) is equal to or less than the predetermined threshold lateral velocity difference Vyth.

Whether or not the condition G2 is satisfied may be determined using the absolute velocity. That is, the condition G2 may be as follows.
The absolute value of the difference between the "vertical absolute velocity of the grouping candidate sensor target Bn" and the "vertical absolute velocity of the grouping reference target Bs" is equal to or less than the threshold longitudinal velocity difference Vxth, and the "grouping candidate sensor target" The absolute value of the difference between "the lateral absolute velocity of Bn" and "the lateral absolute velocity of the grouping reference target Bs" is equal to or less than the threshold lateral velocity difference Vyth.

When the grouping candidate sensor target Bn satisfies the grouping condition consisting of both (condition G1) and (condition G2) with respect to the grouping reference target Bs, the DSPE determines the sensor target Bn and the grouping standard. Integrate with the marker Bs to generate a new fusion target FBn. Further, the DSECU sets identification information (ID) for distinguishing (identifying) the fusion target FBn from other fusion targets with respect to the new fusion target FBn.

For example, in FIG. 8A, the grouping candidate sensor target B1 satisfies both the conditions (condition G1) and (condition G2) with respect to the grouping reference target B0, and the grouping candidate sensor target B2. It is also assumed that both the conditions (condition G1) and (condition G2) are satisfied with respect to the grouping reference target B0. In this case, the DSPE groups (integrates) the sensor target B1 and the sensor target B2 and the sensor target B0 to newly generate the fusion target FB1. The identification information of the fusion target FB1 is, for example, "ID1".

Further, in FIG. 8A, when the grouping candidate sensor target B2 also satisfies both the conditions (condition G1) and (condition G2) with respect to the grouping reference target B0, the DESCU determines the sensor target. B2 is also integrated with the sensor target B0. That is, the sensor target B2 is integrated with the fusion target FB1.

On the other hand, when the grouping candidate sensor target Bn does not satisfy at least one of (condition G1) and (condition G2) with respect to the grouping reference target Bs, the DSPE uses another sensor target Bn. Select as the grouping reference target Bs. Then, in the DESCU, the sensor targets (that is, the sensor targets that have not been integrated into the fusion target by then) that are grouping candidates are (condition G1) and (condition G2) with respect to the grouping reference target Bs. It is determined whether or not both of the grouping conditions of are satisfied. The above process is a new target generation grouping process.

On the other hand, when the fusion target FBn is generated in the previous calculation (calculation before the calculation cycle Δt) (that is, when the fusion target FBn is already generated at the start of the current calculation), the DSPE is used. The fusion target FBn is updated as follows. In the following, as shown in FIG. 9A, an example is used in which two fusion targets FB1 and FB2 (that is, FBn, n = 1, 2) have already been generated when the current calculation is started. The method of updating (generating) the fusion target will be described. Hereinafter, the fusion target generated or updated in the previous calculation is referred to as "previous fusion target", and the target information of the previous fusion target is referred to as "previous fusion target information".

The DESCU estimates the position and relative velocity of the fusion target FBn in this calculation based on the previous fusion target information of the previous fusion target FBn. This estimated fusion target is referred to as the "estimated target FBn'". For example, in the example shown in FIG. 9A, estimated target targets FB1'and FB2'are generated based on the previous fusion targets FB1 and FB2, respectively.

More specifically, in the XY coordinates at the time of the previous calculation (hereinafter, referred to as "previous XY coordinates"), the XY coordinate positions of the previous fusion target FBn are (Xfn, Yfn). Let Vxfn be the vertical relative velocity of the previous fusion target FBn, and Vyfn be the horizontal relative velocity of the previous fusion target FBn. At this time, the DSPE calculates the XY coordinate positions (Xfn', Yfn') of the estimated target FBn'in the previous XY coordinates according to the following formula.

Xfn'= Xfn + Δt · Vxfn
Yfn'= Yfn + Δt · Vyfn

After that, the DSECU sets the obtained "XY coordinate positions (Xfn', Yfn') of the estimated target FBn'in the previous XY coordinates and" to the XY coordinates at the time of this calculation (hereinafter, "" This time, it is called "XY coordinates") and is converted (coordinate conversion) to the XY coordinate position. Further, the DSECU converts (coordinate conversion) the "relative velocity (Vxfn, Vyfn) of the previous fusion target FBn" in the previous XY coordinates into the relative velocity in the XY coordinates this time, and this time XY. It is set as the relative velocity of the estimated target FBn'in coordinates. The DSPE recognizes the relationship between the previous XY coordinates and the current XY coordinates from the time Δt and the like “vehicle speed V, lateral deviation Dy, and yaw angle θy of the own vehicle SV”. From this relationship, the above coordinate conversion such as the XY coordinate position and the relative velocity is performed.

Further, the DSPE sets the "target width and target length" of the estimated target FBn'to the same values as the "target width Wf and target length Lf" of the previous fusion target FBn, respectively. As a result, the DSPE generates the estimated target FBn'(that is, FB1'and FB2').

The estimated target FBn'is a target for grouping (integrating) the sensor target newly detected at the time of this calculation (hereinafter, also referred to as "this detection sensor target"). is there. Therefore, the identification information of the estimated target FBn'is set to the same information as the identification information of the previous fusion target FBn. That is, for example, the identification information of the estimated target FB1'is maintained in the "ID1" which is the identification information of the previous fusion target FB1. The identification information of the estimated target FB2'is maintained in "ID2" which is the identification information of the previous fusion target FB2.

Next, the DSPE extracts the sensor target this time, which is a grouping candidate for the estimated target FBn'. This extraction is based on the position of the estimated target FBn'. More specifically, the DSPE extracts the "current detection sensor target" in the grouping target area determined based on the position of the estimated target FBn'as the grouping target of the estimated target FBn'.

In the example shown in FIG. 9A, the sensor target BFC1 is the current detection sensor target detected by the central front peripheral sensor 16FC. The sensor targets BFL1, BFL2, and BFL3 are the current detection sensor targets detected by the left front peripheral sensor 16FL this time. The sensor target BRL1 is the current detection sensor target detected this time by the left rear peripheral sensor 16RL. Neither the left front peripheral sensor 16FL nor the right rear peripheral sensor 16RR has detected the detection sensor target this time. Grouping candidates for the estimated target FB1'are "sensor target BFC1, sensor target BFL1, BFL2 and BFL3, and sensor target BRL1" surrounded by the dotted line R1. The grouping candidate for the estimated target FB2'is the "sensor target BRL1" existing in the grouping target area surrounded by the dotted line R2.

The DESCU executes a grouping process (hereinafter, referred to as "first grouping process") for associating the detection sensor target with the previous fusion target FBn based on the estimated target FBn'.

That is, the DSPE first selects the estimated target FBn'as the grouping reference target. Next, the DSPE sets a grouping condition in which the current detection sensor target, which is a grouping candidate, comprises the above-mentioned (condition G1) and (condition G2) with respect to the grouping reference target (that is, the estimated target FBn'). Determine if it is satisfied. In this way, when the grouping reference target is the estimated target FBn', the target information of the grouping reference target is the target information (XY coordinate position, vertical relative velocity, and horizontal relative) of the estimated target FBn'. Speed) is used.

When the current detection sensor target of the grouping candidate satisfies both the conditions (condition G1) and (condition G2) with respect to the estimated target FBn'selected as the grouping reference target, the DSECU determines the estimated target. The fusion target FBn is updated (generated) by integrating the FBn'and the detection sensor target this time. The DSECU performs this process on all of the grouping candidate current detection sensor targets to update the fusion target FBn. The identification information of the fusion target FBn is maintained in the same information as the identification information of the estimated target FBn'.

In the example shown in FIG. 9B, among the currently detected sensor targets of the grouping candidates surrounded by the dotted line R1 with respect to the estimated target FB1', the sensor target BFC1 and the sensor target BFL1 are (condition G1). It is assumed that both the conditions (that is, the grouping condition) of (condition G2) are satisfied. In this case, as shown in FIG. 10, the DSPE updates (generates) the fusion target FB1 by integrating the estimated target FB1'and the "sensor target BFC1 and the sensor target BFL1". The number of sensor targets (grouping characteristics) determined to be integrated into the estimated target FB1'is "2".

Further, in the example shown in FIG. 9B, it is assumed that the sensor target BRL1 which is a grouping candidate does not satisfy the grouping condition with respect to the estimated target FB2'. That is, there is no sensor target that satisfies the grouping condition among the currently detected sensor targets of the grouping candidates surrounded by the dotted line R2 with respect to the estimated target FB2'. In other words, the number of sensor targets (grouping characteristic) determined to be integrated with the estimated target FB2'is "0". In this case, the DESCU extrapolates the fusion target FB2. That is, the DSPE regards the estimated target FB2'as the current fusion target FB3 obtained by extrapolating the fusion target FB2 last time, and the target information of the current fusion target is the estimated target FB3'. Replace with the target information of. This process is referred to as extrapolation or extrapolation of the fusion target.

Further, when there is a detection sensor target (hereinafter, also referred to as “residual sensor target”) that has not been integrated with any of the estimated targets by the first grouping process, the DSPE is used between the residual sensor targets. Try grouping. This process is called a second grouping process.

For example, in the example shown in FIG. 10, the "sensor target BFL2 and BFL3 and the sensor target BRL1" surrounded by the dotted line R3 are residual sensor targets. The DESCU executes the same process as the above-mentioned "new grouping process" for these residual sensor targets as the second grouping process. As a result, the DSPE generates a new fusion target FBn.

As described above, when the grouping characteristic number with respect to the estimated target FBn'is "0", the DSPE extrapolates the fusion target FBn this time based on the estimated target FBn'. Extrapolation of the fusion target is continued until the duration (extrapolation duration) from the start of the extrapolation becomes the predetermined maximum extrapolation duration tg or more, and the extrapolation duration is the maximum extrapolation continuation. It ends when the time tg is reached. In this case, the DESCU determines that the fusion target has been lost. On the other hand, before the extrapolation duration reaches the maximum extrapolation duration tg, a sensor target that is integrated with the estimated target corresponding to the fusion target by the extrapolation appears, and the sensor target appears. Is integrated into the putative target, the DSECU ends the extrapolation of the fusion target.

(Specific operation)
Next, the specific operation of the present implementation device will be described. The CPU of the DSPE (hereinafter, simply referred to as “CPU”) executes the target tracking routine shown in FIG. 11 every time a predetermined time (predetermined calculation cycle) Δt elapses at a predetermined timing. ..

Therefore, when the predetermined timing is reached, the CPU starts the process from step 1100 in FIG. 11 and proceeds to step 1110 to determine whether or not the previous fusion target exists. That is, the CPU determines whether or not the fusion target has been generated or extrapolated at the time of the previous execution of this routine.

If the fusion target does not exist last time, the CPU determines "No" in step 1110, proceeds to step 1120, and executes the new grouping process described above. After that, the CPU proceeds to step 1160 or later, which will be described later.

On the other hand, when the fusion target does not exist last time, the CPU determines "Yes" in step 1110, performs the processes of steps 1130 to 1150 described below in order, and then proceeds to step 1160 and subsequent steps.

Step 1130: The CPU generates an estimated target based on the previous fusion target according to the technique described above. At this time, the identification information of the estimated target is set to be the same as the identification information of the previous fusion target information from which the estimated target was generated.
Step 1140: The CPU executes the first grouping process according to the method described above.
Step 1150: The CPU executes the second grouping process according to the method described above.

When the CPU finishes the process of step 1120 or step 1150, the process of steps 1160 to 1180 described below is performed in order, and the process proceeds to step 1195 to temporarily end this routine.

Step 1160: The CPU makes a lost determination according to the method described above. That is, the CPU identifies the fusion target that can be determined to have disappeared from the previous fusion targets.
Step 1170: The CPU extrapolates the fusion target based on the estimated target with a grouping characteristic of "0" according to the technique described above.

Step 1180: The CPU updates the fusion target information according to the method described above. At this time, if the above-mentioned mixed fusion target exists in the fusion target generated / updated in step 1120, step 1140, and step 1150, the CPU is a high AGE sensor belonging to the mixed fusion target. A high-precision high-AGE sensor target is extracted from the target, and the horizontal position included in the sensor target information of the extracted high-precision high-AGE sensor target is used to determine the target width Wf of the mixed fusion target FBn. Calculate.

<Modification example>
Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications based on the technical idea of the present invention are possible.

For example, in the above-described embodiment, the mixed fusion target is a fusion target including sensor targets detected by both the left rear peripheral sensor 16RL and the right rear peripheral sensor 16RR, but a plurality of peripheral radar sensors 16a Two other peripheral sensors selected from among (for example, two peripheral sensors of the central front peripheral sensor 16FC and the right front peripheral sensor 16FR, or two peripheral sensors of the central front peripheral sensor 16FC and the left front peripheral sensor 16FL). ) May be a fusion target including the sensor target detected by.

In this case, the reference axis is a straight line connecting points where the radiation angle θh of the radar wave of one peripheral sensor and the radiation angle θh of the radar wave of the other peripheral sensor are the same. Then, the DSECU depends on which of the two peripheral sensors the high AGE target is closer to the reference axis from among the plurality of high AGE sensor targets belonging to the mixed fusion target. Then, a high-precision and high-precision AGE sensor target for calculating the width Wf of the fusion target may be extracted.

Further, the mounting position of the plurality of peripheral radar sensors 16a is not limited to the above-described embodiment. In addition, in the above embodiment, the sensor target is treated as a high AGE sensor target and a low AGE sensor target separately, but such a distinction is not always necessary. For example, the peripheral radar sensor 16a may be configured to transmit only the sensor target determined to be a high AGE target and the sensor target information thereof to the DESCU.

10 ... Driving support ECU, 15 ... Vehicle speed sensor, 16a ... Peripheral radar sensor, 16FC ... Center front peripheral sensor, 16FR ... Right front peripheral sensor, 16FL ... Left front peripheral sensor, 16RR ... Right rear peripheral sensor, 16RL ... Left rear peripheral Sensor, 16b ... Camera sensor, 17 ... Operation switch, 52 ... Steering motor, 53 ... Winker lever switch

Claims (1)

Each emits radar waves in a range around the own vehicle and having a predetermined angular width to the left and right with respect to the radiation center axis, and the point of reflection of the emitted radar waves by a three-dimensional object is a sensor target. A plurality of radar sensors that detect as, and acquire the vertical position, horizontal position, and relative speed of the detected sensor target with respect to the own vehicle as sensor target information.
When a plurality of the sensor targets are detected, fusion indicating the same three-dimensional object by grouping the sensor targets that are likely to detect the same three-dimensional object among the plurality of sensor targets. Fusion target generation means for generating targets, and
The width of the fusion target, which is one of the attribute values of the fusion target, is calculated based on the sensor target information of the sensor targets grouped so as to generate the fusion target. Information calculation means and
In the target information acquisition device equipped with
The plurality of radar sensors
A first region including a first radar sensor and a second radar sensor, which is a region where the first radar sensor can detect the sensor target and a region where the second radar sensor can detect the sensor target. It is mounted on the own vehicle so as to have an area overlapping with the second area.
The fusion target information calculation means
At least one of the sensor targets grouped so as to generate the fusion target is a first sensor target which is a sensor target detected by the first radar sensor, and the fusion target. When at least the other one of the sensor targets grouped to generate is a second sensor target, which is a sensor target detected by the second radar sensor.
The second radar, which is the angle between the radiation center axis of the first radar sensor and the radiation center axis of the second radar sensor, which is the angle formed by the second sensor target with the radiation center axis of the first radar sensor. When the sensor is located in a region close to the first radar sensor with respect to the reference axis, which is a set of points equal to the sensor radiation angle, the sensor target information of the second sensor target is not used. The width of the fusion target is calculated using the horizontal position included in the sensor target information of the first sensor target.
When the first sensor target is located in a region closer to the second radar sensor with respect to the reference axis, the second sensor target information of the first sensor target is not used. The width of the fusion target is calculated using the horizontal position included in the sensor target information of the sensor target.
A target information acquisition device configured as follows.

Images