JP6828602B2 - Target detection device - Google Patents

Description

The present invention relates to a target detection 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. Obtains 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"). 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 detection device that acquires target information of a three-dimensional object existing around the own vehicle" is adopted not only in the lane change support device but also in other driving support devices.

JP-A-2009-274594

By the way, as is well known, a radar sensor transmits a radar wave around itself, receives a reflected wave generated by the radar wave being reflected by a three-dimensional object, and is based on the received reflected wave. Recognize the target and acquire the target information. For this reason, the detection range, performance, and at least one of the surrounding environment of the radar sensor mounted on the own vehicle may temporarily prevent the target existing around the own vehicle from being detected. It may not be possible to accurately determine the presence of surrounding objects.

Therefore, in the conventional target detection device, after the target is no longer detected by the radar sensor, uninterrupted object detection is performed by performing extrapolation processing unless the target is re-detected. There is. Further, in the conventional target detection device, when the extrapolation process is performed for a certain maximum extrapolation duration or longer, it is determined that the sensor target for which the extrapolation process has been performed does not exist.

The extrapolation process (sometimes referred to simply as "extrapolation") is the target information of the detected target when it was detected or an estimated value based on the target information. A process of extrapolating a target by estimating the target information of the undetected target based on the target information and replacing the target information of the undetected target with the estimated target information. To say.

However, by setting the maximum extrapolation duration for extrapolating the target to be constant, the following problems may occur.
-Temporarily falsely detected targets such as noise and ghosts are also extrapolated for a certain period of time after they are no longer detected. As a result, although there is a high possibility that the target does not actually exist around the own vehicle, the determination that the target exists continues for an unnecessarily long time.
・ If the relative speed of the target with respect to the own vehicle is small, the maximum extrapolation duration may be shorter than the time between entering the blind spot of the radar sensor near the own vehicle and escaping. obtain. In this case, the extrapolation may be completed while the target remains in the blind spot of the radar sensor, and it may be erroneously determined that the target exists in the vicinity of the own vehicle but does not exist. obtain.

Further, in the conventional device, the magnitude of the parameter (hereinafter, also referred to as “existence probability”) that increases at a constant rate of increase in proportion to the number of continuous operations in which the target is continuously detected is large. Indeed, the maximum extrapolation duration is set to be long.

However, an erroneously detected target having a characteristic of staying in one place for a long time (for example, a target erroneously detected that each of a wall, a road surface, a roadside object, etc. is a moving object) is a target for the own vehicle. Relative positions tend to stay in the same position for a long time. For this reason, the maximum extrapolation duration is set longer as the existence probability of such a falsely detected target increases, and after the falsely detected target is no longer detected, it is outside for an unnecessarily long time. By being inserted, it may be determined that a false positive target exists for a long time. Then, the detection position of the false detection target is falsely detected, and for example, when the false detection position is on the lane, it may be determined that the false detection target exists on the lane for a long time. ..

The present invention has been made to address the above-mentioned problems. That is, one of the objects of the present invention is that an appropriate maximum extrapolation duration can be set according to the type of the detected target, and the existence of an accurate or appropriate target can be determined. An object of the present invention is to provide a target detection device (hereinafter, also referred to as “the device of the present invention”).

Each device of the present invention detects the reflection point of the radar wave transmitted around the own vehicle by a three-dimensional object as a sensor target, and the vertical distance, the horizontal position, and the relative speed of the detected sensor target with respect to the own vehicle. A plurality of radar sensors (16FC, 16FL, 16FR, 16RL and 16RR) for detecting position and velocity information for acquiring sensor target information including
The existence probability calculation means (10) for calculating the existence probability of the detected sensor target (step 1015),
When the detected sensor target is no longer detected, the position / velocity information at the time when the detected sensor target is detected is used as long as the detected sensor target is not re-detected. Extrapolation processing means for performing extrapolation processing (step 1030) to generate an extrapolated sensor target by estimating the sensor target information of the detected sensor target based on the sensor target information based on the sensor target information. (10) and
The maximum extrapolation duration, which is the maximum value of the extrapolation processing time, is calculated based on the existence probability and the vertical relative velocity (Vxobj) of the detected sensor target (step 1025). Time calculation means and
When the extrapolation process is performed for the maximum extrapolation duration or longer (determined as "Yes" in step 1040), it is determined that the sensor target for which the extrapolation process has been performed does not exist (step 1045). Mark existence determination means (10) and
With
The existence probability calculation means
When the sensor target is detected, the vertical relative speed of the sensor target is increased so that the increase rate of the existence probability increases as the magnitude (| Vxobj |) of the vertical relative speed of the sensor target increases. The increase rate of the existence probability is obtained based on (BK1), and the existence probability is determined based on the value corresponding to the time during which the sensor target is continuously detected and the increase rate of the existence probability. It is configured to calculate the existence probability by integrating the increase amount (step 1015).
The maximum extrapolation duration calculation means is
The maximum extrapolation duration is set so that the maximum extrapolation duration becomes longer as the existence probability increases, and the maximum extrapolation duration becomes longer as the magnitude of the longitudinal relative velocity decreases (BK2). It is configured to calculate (step 1025).

According to this, an appropriate maximum extrapolation duration can be set according to the type of the sensor target, and therefore, the existence of the sensor target can be accurately or appropriately determined.

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. Other objects, other features and accompanying advantages of the present invention will be readily understood from the description of embodiments of the present invention described with reference to the following drawings.

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 plan view of the own vehicle and the road for explaining the lane keeping control. FIG. 4 is a graph showing the relationship between the vertical relative velocity and the ascending rate. FIG. 5 is a plan view of the own vehicle, a three-dimensional object, and a road showing the blind spot area of the peripheral radar sensor. FIG. 6 is a graph showing the relationship between the absolute value of the vertical relative velocity, the maximum extrapolation time, and the existence probability. 7 (A), (B) and (C) are diagrams for explaining a grouping process for integrating sensor targets. 8 (A) and 8 (B) are diagrams for explaining a grouping process for integrating sensor targets. FIG. 9 is a diagram for explaining a grouping process for integrating sensor targets. FIG. 10 is a flowchart showing a routine executed by the CPU of the driving support ECU shown in FIG.

Hereinafter, the target detection device according to the embodiment of the present invention will be described with reference to the drawings. This target detection 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 the detection signal or the output signal of the sensor from the ECU to which the sensor is connected via the CAN.

Accelerator pedal operation amount sensor 11 that detects the operation amount AP of the accelerator pedal 11a.
Brake pedal operation amount sensor 12 that detects the operation amount BP 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 Vsx, 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. The peripheral radar sensor 16a may be simply referred to as a "radar sensor".

Peripheral sensors 16FC, 16FR, 16FL, 16RR and 16RL are referred to as peripheral radar sensors 16a when it is not necessary to distinguish them individually. The peripheral sensors 16FC, 16FR, 16FL, 16RR and 16RL have substantially the same configuration as each other.

The peripheral radar sensor 16a includes a radar transmission / reception unit and a signal processing unit (not shown). The radar transmitter / receiver emits radar waves (hereinafter referred to as "millimeter waves"), which are radio waves in the millimeter wave band, and further, three-dimensional objects (for example, other vehicles, pedestrians, bicycles) existing within the radiation range. And receive millimeter waves (ie, reflected waves) reflected by buildings, etc.). A point of a three-dimensional object that reflects radar 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. Therefore, the reflection point information indicating 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 direction of the reflection point of the three-dimensional object with respect to the own vehicle SV is predetermined. Acquire (detect) every time the time elapses. 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. 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. The right rear peripheral sensor 16RR is provided at the right rear corner of the vehicle body, and mainly detects a sensor target existing in the right rear region of the own vehicle SV. The left rear peripheral sensor 16RL is provided at the left rear corner of the vehicle body, and mainly detects a sensor target existing in the left rear region of the own vehicle SV. 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". Each time the calculation cycle elapses, the DSPE directly acquires the above-mentioned reflection point information from the peripheral radar sensor 16a, and calculates and obtains the "sensor target information" based on the reflection point information. Sensor target information may be acquired.

-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. That is, each of the peripheral radar sensors 16a may acquire a plurality of sets of sensor target information. Further, two or more peripheral radar sensors 16a may acquire a plurality of sets of sensor target information 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. The curvature Cu is defined to have a positive value when the lane center line CL is curved to the right and a negative value when the lane center line CL is curved to the left.

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. 3, 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. The signed distance Dy becomes a positive value when the reference point P of the own vehicle SV shifts to the right side in the road width direction with respect to the lane center line CL, and the reference point P of the own vehicle SV is the lane center line CL. It is defined to be a negative value when shifting to the left side 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 left and right white lines and the shape of the white lines in the lane adjacent to the own lane. 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 following 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. In addition, the operation switch 17 also has a function of causing the driver to input or select a parameter for reflecting the driver's preference when executing each of the above controls.

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 described later.

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 DSP ECU, 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 sound the buzzer 71 to alert the driver in response to an instruction from the DSECU. Further, the display ECU 70 lights a warning mark (for example, a warning lamp) on the display 72, displays an alarm image, displays a warning message, and controls driving support in response to an instruction from the DSECU. It is possible to display the operating status of. Although the display 72 is a head-up display, it may be another type of display.

(Overview of basic driving support control)
As described above, the DSECU is adapted to execute the following inter-vehicle distance control, the lane keeping control, and the 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. Hereinafter, these controls will be briefly described.

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>
The DSECU confirms that there is no three-dimensional object (other vehicle) that is unnecessarily close to the own vehicle SV even if the own vehicle SV changes lanes by the lane change support control at least when executing the lane change support control. .. Therefore, as described above, the DSPE generates a fusion target by grouping a plurality of sensor targets based on the sensor target information. When the DESCU determines that a lane change support request for lane change support control has occurred, the own vehicle SV collides with the fusion target existing in the target adjacent lane of the own vehicle SV based on the target information of the fusion target. The time until the collision margin time (collision margin time TTC) is calculated, and when the collision margin time TTC is equal to or greater than the threshold value, the lane change support control is started.

First, a method of acquiring a sensor target that is a source of generating a fusion target will be described. This sensor target includes not only the actually detected sensor target but also the “extrapolated sensor target” described later.

The DSECU determines based on the sensor target ID whether or not the sensor target (hereinafter referred to as "previous sensor target") one calculation cycle (Δt) before is detected in this calculation. .. When the sensor target is detected last time in this calculation, the DSPE updates the existence probability of the sensor target. The calculation method of the existence probability will be described later.

On the other hand, if the sensor target was not detected last time in this calculation, the DSPE performs extrapolation processing. That is, the DESCU estimates the "sensor target information (for example, position and relative velocity) of the sensor target corresponding to the previous sensor target" in this calculation based on the sensor target information of the previous sensor target. .. Hereinafter, the "sensor target corresponding to the previous sensor target in this calculation" will be referred to as the "current estimated sensor target".

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 sensor target Bn are (Xobj, Yobj). Let Vxobj be the vertical relative velocity of the previous sensor target Bn, and Vyobj be the horizontal relative velocity of the previous sensor target Bn. At this time, the DESCU calculates the XY coordinate positions (Xobj', Yobj') of the current estimated sensor target Bn'in the previous XY coordinates according to the following formula.

Xobj'= Xobj + Δt ・ Vxobj
Yobj'= Yobj + Δt ・ Vyobj

After that, the DSECU sets the obtained "XY coordinate positions (Xobj', Yobj') of the current estimated sensor target Bn'in the previous XY coordinates" to the XY coordinates (hereinafter, hereafter, Yobj') at the time of this calculation. It is converted (coordinate conversion) to the XY coordinate position in "the XY coordinates this time"). As a result, the position of the estimated sensor target this time (this time XY coordinates) can be obtained.

Further, the DESCU converts (coordinate conversion) the "relative velocity (Vxobj, Vyobj) of the previous sensor target Bn" in the previous XY coordinates to the relative velocity in the XY coordinates this time. This is set as the relative velocity of the current estimated sensor target Bn'in the XY coordinates this time. The DSPE recognizes the relationship between the previous XY coordinates and the current XY coordinates from "the vehicle speed V of the own vehicle SV, the lateral deviation Dy, and the yaw angle θy" and the time Δt, and this From the relationship, the above coordinate conversion such as XY coordinate position and relative velocity is performed. In this way, the DSPE extrapolates the sensor target.

On the other hand, the DSPE calculates the maximum extrapolation duration for continuing the extrapolation when starting the extrapolation of the sensor target. The calculation method of the maximum extrapolation duration will be described later.

Then, every time the calculation cycle (Δt) elapses, the DSPE determines whether or not the previous sensor target that is no longer detected has been rediscovered. That is, the DSPE determines whether or not a sensor target having the same target ID as the previous sensor target that is no longer detected is detected. The DSECU repeatedly extrapolates the sensor target unless the previous sensor target that is no longer detected is re-detected. The second and subsequent extrapolation of the sensor target is executed based on the sensor target information extrapolated at the time of the previous calculation. Further, the DSECU determines that the sensor target no longer exists (lost) when the extrapolation duration exceeds the maximum extrapolation duration by repeating the extrapolation.

(Calculation of existence probability)
When the previous sensor target detected by the peripheral radar sensor 16a one calculation cycle (Δt) before is detected at the current calculation (at the time of calculation), the DESCU uses the following equation (A) to perform the previous sensor object. The existence probability of the sensor target in this calculation is calculated by adding a predetermined existence probability to the existence probability of the mark.

Trst = Trst _pre + rup x Cy ... (A)
(Trst: Existence probability of sensor target in this calculation, Trst _pre : Existence probability of previous sensor target, rup: Increase rate of existence probability, Cy: Number of calculation cycles)

Therefore, as the number of calculation cycles in which the sensor target is continuously detected by the peripheral radar sensor 16a increases (the longer the period in which the sensor target continues to be detected), the existence probability is calculated to increase. At this time, as shown in FIG. 4, the DSNC sets the increase rate rup of the existence probability so as to increase as the magnitude (absolute value) of the vertical relative velocity Vxobj of the sensor target increases.

As a result, the existence probability of a sensor target having a low vertical relative velocity Vxobj as described below is less likely to increase.
-The magnitude of the vertical relative velocity Vxobj that occurs when a road surface, wall, roadside object, etc. is falsely detected (false positive) is low. The magnitude of the vertical relative velocity Vxobj that occurs when a sensor target or sensor ghost is detected (detected). Low sensor target ・ Sensor target with a low vertical relative velocity Vxobj that occurs when another vehicle with approximately the same velocity as the own vehicle is detected.

On the other hand, the existence probability of a sensor target having a large vertical relative velocity Vxobj and approaching from a distance tends to be large.

(Calculation of maximum extrapolation duration)
By the way, as shown in FIG. 5, a three-dimensional object 150 having a small vertical relative velocity Vxobj recognized as a sensor target may enter and stay in the blind spot region Rdl or Rdr of the peripheral radar sensor 16a. obtain. In this case, when the three-dimensional object 150 enters the blind spot region Rdl or Rdr, the sensor target from the three-dimensional object 150 cannot be detected, so the DESCU starts extrapolation of the sensor target. After that, the three-dimensional object 150 continues to stay in the blind spot region Rdl or Rdr, and if the sensor target is not detected from the three-dimensional object 150, the DSPEC continues the extrapolation. At this time, if the maximum extrapolation duration is short, the extrapolation of the sensor target is completed while the three-dimensional object 150 remains in the blind spot region, and the sensor target corresponding to the three-dimensional object 150 is determined to be lost. It can happen. In this case, even though the three-dimensional object 150 exists in the vicinity of the own vehicle, it is erroneously determined that the sensor target corresponding to the three-dimensional object 150 does not exist in the vicinity of the own vehicle. Therefore, even if another vehicle (three-dimensional object 150) exists in the blind spot region Rdl or Rdr of the peripheral radar sensor 16a and in the region that hinders the lane change support, the execution of the lane change support control is erroneously executed. It is possible to allow it.

On the other hand, as the magnitude of the vertical relative velocity Vxobj of the sensor target becomes smaller, such a problem can be avoided by setting the maximum extrapolation duration longer.

However, in this case, a sensor having a small vertical relative velocity Vxobj when erroneously detecting a road surface, a wall, a roadside object, etc., and a sensor having a small vertical relative velocity Vxobj when detecting a sensor ghost. The maximum extrapolation duration of a target can also be long. In this case, even though the sensor target does not actually exist around the own vehicle, the determination that the sensor target exists around the own vehicle continues for an unnecessarily long time. As a result, the execution of the lane change support control is prohibited for an unnecessarily long time, and the return to the state in which the lane change support control can be executed is delayed.

Therefore, as shown in FIG. 6, the DSPE of the present implementation device has a longer maximum extrapolation duration as the existence probability increases, and a maximum extrapolation duration as the vertical relative velocity Vxobj decreases. Calculate the maximum extrapolation duration so that it is longer.

As a result, after approaching the own vehicle from a distance while having a large vertical relative velocity Vxobj, the behavior is such that the vehicle stays in the blind spot area near the own vehicle. "The existence probability is high and the vertical relative velocity Vxobj is large. The maximum extrapolation duration of the "small sensor target" can be increased. On the other hand, "It occurs when a sensor target and a sensor ghost that occur when a sensor target having a low existence probability and a small vertical relative velocity Vxobj are erroneously detected (for example, a road surface, a wall, a roadside object, etc.) are detected. The maximum extrapolation duration of "sensor target)" can be shortened. Therefore, the present implementation device can accurately determine the existence of the sensor target. As a result, the present implementing device can accurately determine whether or not to perform lane change support control.

(Generation / update of fusion target and lost judgment)
Next, a method of generating / updating a fusion target and determining lost by executing 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. As described above, there are cases where a plurality of sensor targets are acquired from one three-dimensional object.

Therefore, the DSPE performs a grouping process described later to group (integrate, integrate, a plurality of sensor targets (including extrapolated sensor targets) that are likely to be obtained from one three-dimensional object n). By fusing), a fusion target FBn corresponding to the one three-dimensional object n is generated. In other words, the DSPE integrates the plurality of sensor targets to generate the fusion target FBn based on the sensor target information of each of the plurality of sensor targets. Then, the DSPE integrates the fusion target information of the fusion target FBn into the fusion target FBn (that is, belongs to the fusion target FBn), and includes an extrapolated sensor target. .) Generated based on the sensor target information. Hereinafter, the "grouping process" will be described in detail with reference to the examples shown in FIGS. 7A and 7B.

Now, as shown in FIG. 7A, 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. In addition, this grouping process is called "new target generation 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. 7 (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 “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. 7 (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. 7A, it is assumed that the grouping candidate sensor target B1 satisfies both the conditions (condition G1) and (condition G2) with respect to the grouping reference target B0. In this case, the DSPE integrates the sensor target B1 and the sensor target B0 to newly generate the fusion target FB1. In this case, the identification information of the fusion target FB1 is, for example, "ID1".

Further, in FIG. 7A, 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 are grouping candidates (that is, the sensor targets that have not been integrated as fusion targets by then) 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. 8A, 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. 8A, 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" to the XY coordinates at the time of this calculation (hereinafter, "this time". It is converted (coordinate conversion) to the XY coordinate position in (referred to as "XY coordinates"). 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.

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'groups "newly detected sensor target and extrapolated sensor target (hereinafter, also referred to as" this time detected sensor target ")" at the time of this calculation. It is a target that serves as a criterion for integration). 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 "ID1" which is the identification information of the previous fusion target FB1, and the identification information of the estimated target FB2'is the identification information of the previous fusion target FB2. It is maintained at a certain "ID2".

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. 8A, 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 right front peripheral sensor 16FL nor the right rear peripheral sensor 16RR has detected the detection sensor target this time. The grouping candidates for the estimated target FB1'are "sensor target BFC1, sensor target BFL1, BFL2 and BFL3, and sensor target BRL1" existing in the grouping target area 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. In the first grouping process, the threshold vertical distance Xth used in the condition G1 is "target length L1 x 0.5 + predetermined value α", and the threshold lateral distance Yth used in the condition G2 is ". The target width W1 × 0.5 + predetermined value β ”. The "target length and target width" of the estimated target FBn'are used for the target length L1 and the target width W1, respectively.

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'. As a matter of course, the current detection sensor target of the grouping candidate satisfies at least one of (condition G1) and (condition G2) with respect to the estimated target FBn'selected as the grouping reference target. If not, the DSPE does not integrate the estimated target FBn'and its current detection sensor target.

In the example shown in FIG. 8B, 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. 9, the DSPE updates (generates) the fusion target FB1 by integrating the estimated target FB1'and the "sensor target BFC1 and the sensor target BFL1". Therefore, the number of sensor targets (grouping characteristic) determined to be integrated into the estimated target FB1'is "2".

Further, in the example shown in FIG. 8B, 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, as shown in FIG. 9, the DESCU determines that the fusion target has been lost (no longer exists).

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. 9, the “sensor target BFL2 and BFL3 and the sensor target BRL1” surrounded by the dotted line R3 are residual sensor targets. The DSECU executes the same process as the above-mentioned "new target generation grouping process" for these residual sensor targets as the second grouping process.

That is, the DSPE selects one of the residual sensor targets as the grouping reference target, and extracts the residual sensor target that is a grouping candidate for the selected grouping reference target. Next, the DSPE determines whether or not the extracted residual sensor target, which is a grouping candidate, satisfies the above-mentioned grouping condition with respect to the grouping reference target. Then, the DSPE generates a new fusion target FBn by integrating the grouping reference target and the residual sensor target that satisfies the grouping condition. The DESCU sets identification information (ID) for the new fusion target FBn to distinguish (identify) the fusion target FBn from other fusion targets. The DSECU performs such processing on all of the residual sensor targets.

(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”) performs the sensor target tracking routine shown in FIG. 10 every time a predetermined time (calculation cycle) Δt elapses at a predetermined timing. This is executed for each of the marks Bn (that is, the sensor target ID transmitted from the peripheral radar sensor 16a).

Therefore, when the predetermined timing is reached, the CPU starts processing from step 1000 of the sensor target tracking routine and proceeds to step 1005, and the previous sensor target detected by the peripheral radar sensor 16a one calculation cycle before is detected this time as well. Whether or not it is completed is determined based on the sensor target ID described above.

If the previous sensor target can be detected this time as well, the CPU determines "Yes" in step 1005, performs the processes of steps 1010 and 1015 in order, and then proceeds to step 1095. Terminate the routine once.
Step 1010: The target information of the sensor target is updated with the target information of the sensor target detected this time.
Step 1015: The CPU uses the lookup table Map1 (hereinafter, also referred to as “map”) in which the magnitude of the vertical relative velocity Vxobj included in the target information of the sensor target Bn updated in step 1010 is shown in the block BK1. By applying to.), The rate of increase rup of the existence probability of the sensor target Bn is calculated. Further, the CPU applies the "previous existence probability Trst _pre , increase rate rup of existence probability, and number of calculation cycles Cy" of the sensor target Bn to the equation (A), thereby causing the current existence probability of the sensor target Bn. Calculate Trst.

Trst = Trst _pre + rup x Cy ... (A)

On the other hand, if the previous sensor target could not be detected this time, the CPU determines "No" in step 1005 and proceeds to step 1020 to determine whether the sensor target is already extrapolated. To do.

When the sensor target Bn is not an extrapolated sensor target at the time of processing in step 1020 (that is, the sensor target detected at the time of the previous calculation is detected at the time of this calculation). If not), the CPU determines "Yes" in step 1020 and proceeds to step 1025.

In step 1025, the CPU applies the magnitude of the "previous existence probability Trst _pre and the vertical relative velocity Vxobj of the previous sensor target" of the sensor target Bn to the map Map2 shown in the block BK2, thereby extrapolating. The insertion duration Tg is calculated.

After that, the CPU proceeds to step 1030, estimates the target information of the current sensor target based on the target information of the previous sensor target, and estimates the target information of the current sensor target. Update by replacing with information. That is, the CPU extrapolates the sensor target described above. After that, the CPU proceeds to step 1095 and temporarily ends this routine.

If the sensor target Bn is already extrapolated at the time of processing in step 1020, the CPU determines "No" in step 1020, proceeds to step 1025, and increments the number of extrapolation continuations t by "+1". ..

After that, the CPU proceeds to step 1035, calculates the residual extrapolation time Tg'by subtracting the extrapolation duration (t × Δt (one calculation cycle) seconds) from the maximum extrapolation duration Tg, and then proceeds to step 1040. It advances and determines whether or not the residual extrapolation time Tg'is 0 or less.

If the residual extrapolation time Tg'is not 0 or less, the CPU determines "No" in step 1045 and proceeds to step 1030, and based on the target information of the previous sensor target, the sensor target object. The target information is estimated, and the target information of the sensor target is updated to the estimated target information. That is, the CPU extrapolates the sensor target.

When the residual extrapolation time Tg'is 0 or less, the CPU determines "Yes" in step 1040 and proceeds to step 1045, determines that the sensor target is lost, and then proceeds to step 1095 to perform this routine. It ends once.

The present implementation device described above sets the rate of increase so that the smaller the magnitude of the vertical relative velocity Vxobj of the sensor target with respect to the own vehicle, the smaller the rate of increase of the existence probability of the sensor target in each calculation cycle. I'm looking for. Further, the present implementation device is the maximum outside of the extrapolation process (extrapolation of the sensor target) performed when the previous sensor target detected by the peripheral sensor one calculation cycle before is not detected in the current calculation cycle. The insertion duration is set so that the larger the existence probability of the sensor target, the longer the insertion duration, and the smaller the magnitude of the vertical relative velocity Vxobj, the longer the insertion duration. As a result, an appropriate maximum extrapolation duration can be set according to the type of the sensor target, and thus the existence determination of the sensor target can be performed with high accuracy. As a result, it is possible to accurately determine whether or not lane change support control may be performed.

<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, it is a premise for executing the lane change support control that the following inter-vehicle distance control and the lane keeping control are being executed, but such a premise is not always necessary. do not do.

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 detects the reflection point of the radar wave transmitted around the own vehicle by a three-dimensional object as a sensor target, and the sensor target including the vertical distance, the lateral position, and the relative speed of the detected sensor target with respect to the own vehicle. Multiple radar sensors that detect position and velocity information to acquire information,
Existence probability calculation means for calculating the existence probability of the detected sensor target, and
When the detected sensor target is no longer detected, the position / velocity information at the time when the detected sensor target is detected is used as long as the detected sensor target is not re-detected. An extrapolation processing means for performing extrapolation processing to generate an extrapolated sensor target by estimating the sensor target information of the detected sensor target based on the sensor target information based on the sensor.
The maximum extrapolation duration calculation means for calculating the maximum extrapolation duration, which is the maximum value of the time for performing the extrapolation process, based on the existence probability and the vertical relative velocity of the detected sensor target.
When the extrapolation process is performed for the maximum extrapolation duration or longer, the sensor target presence determination means for determining that the sensor target for which the extrapolation process has been performed does not exist, and
With
The existence probability calculation means
The existence probability on the basis of the longitudinal relative velocity of the sensor target object such that the sensor was vertical relative velocity magnitude is larger the increase rate of the existence probability of the target is increased when the sensor target object is detected The increase rate of the existence probability is obtained, and the increase amount of the existence probability determined based on the value corresponding to the time during which the sensor target is continuously detected and the increase rate of the existence probability is integrated. It is configured to calculate the probability of existence,
The maximum extrapolation duration calculation means is
The maximum extrapolation duration is calculated so that the maximum extrapolation duration becomes longer as the existence probability increases and the maximum extrapolation duration becomes longer as the magnitude of the longitudinal relative velocity decreases. Consists of,
Target detection device.

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