Vehicle moving object detection device

Abstract

To enable verification with high accuracy whether an object detected by a rear side sensor is identical to an object detected by a front side sensor.SOLUTION: A reference targe extraction unit 12a extracts a nearest targe from targets detected by rear side sensors 28 and 29 and front side sensors 26 and 27 in one frame as a reference target T. An interpolation area setting unit 12b sets rearward interpolation areas Irl and Irr in scanning areas 28A and 29A of the rear side sensors 28 and 29, and sets frontward interpolation areas Ifl and Ifr in scanning areas 26A and 27A of the front side sensors 26 and 27. An estimation trajectory setting unit 12c sets an estimated trajectory Q on the time axis that estimates the movement to the frontward interpolation areas Ifl and Ifr based on the reference target T in the rearward interpolation areas Ifl and Irr. A target verification unit 12d compares the estimated trajectory Q and the reference target T in the frontward interpolation areas Ifl and Ifr on the same time axis to verify whether or not they coincide.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a moving object detection device for a vehicle that sets a rear-side interpolation area and a front-side interpolation area in the scanning area of ​​a rear-side detection unit and the scanning area of ​​a front-side detection unit, and checks whether a first target and a second target detected in each of these interpolation areas match. [Background technology]

[0002] Conventionally, a technology is known in which side sensors (front side sensors and rear side sensors) installed on the front left and right and rear left and right of the vehicle transmit a transmission wave of a predetermined pulse waveform to an adjacent lane, receive a reflected wave from a moving object moving in the adjacent lane, and calculate the round-trip propagation time until the reflected wave is received and the received direction based on the transmission timing of the transmitted wave and the reception timing of the received wave, thereby acquiring moving object information such as the distance to the moving object relative to the vehicle, relative vehicle speed, and position.

[0003] However, between the scanning area of ​​the front side sensor and the scanning area of ​​the rear side sensor, a dead zone (blind spot area) due to the sensor characteristics is formed, as disclosed in Patent Document 1 (JP Patent Publication 2019-66447 A), for example. This dead zone is a section where detection of a moving object is interrupted from when the moving object leaves the scanning area of ​​the rear side sensor to when the moving object enters the scanning area of ​​the front side sensor.

[0004] For example, when a moving object such as a vehicle or a motorcycle traveling in a lane adjacent to the vehicle attempts to overtake the vehicle from behind, the moving object first enters the scanning area of ​​the rear side sensor, exits the scanning area, passes through the dead zone, and enters the scanning area of ​​the front side sensor. If the part of the moving object closest to the vehicle is treated as a target, the target cannot be detected while passing through the dead zone. Therefore, it is necessary to verify whether the target detected in the scanning area of ​​the front side sensor is the same as the target detected in the scanning area of ​​the rear side sensor.

[0005] In this case, the scanning areas of the front side sensors and the rear side sensors are known in advance, and the dead zone is also specified in advance. Therefore, by calculating the movement trajectory of the target based on the target detected by the rear side sensors at every predetermined period, it is possible to estimate the time and position until the movement trajectory passes through the dead zone and enters the scanning area of ​​the front side sensors.

[0006] As a result, by comparing the entry time and position of the target detected in the scanning area of ​​the front side sensor with the movement trajectory of the target obtained by the front side sensor (entry time and position into the scanning area of ​​the front side sensor), it is possible to confirm whether the target detected in the scanning area of ​​the front side sensor is the same as the target detected by the rear side sensor. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2019-66447 A Summary of the Invention [Problem to be solved by the invention]

[0008] However, the reflected waves received by the rear side sensors contain various noise components superimposed thereon in addition to the reflected waves from the above-mentioned targets. Therefore, simply comparing the movement trajectory estimated based on the target detected by the rear side sensors with the target detected by the front side sensors cannot eliminate the noise components from the same movement. target There is a possibility that it may be erroneously detected as such.

[0009] In view of the above circumstances, the present invention aims to provide a moving object detection device for a vehicle that can determine with high accuracy whether a target detected by a rear side sensor and a target detected by a front side sensor are the same, thereby preventing erroneous detection. [Means for solving the problem]

[0010] The present invention includes a rear side detection unit that scans the rear side of the vehicle to detect a first target, a front side detection unit that scans the front side of the vehicle to detect a second target, and a moving body detection unit that detects the movement of a moving body identified by the target based on the targets detected by the rear side detection unit and the front side detection unit. A dead zone that cannot be scanned is formed between the rear-side scanning area scanned by the rear-side detection unit and the front-side scanning area scanned by the front-side detection unit. In the vehicle moving object detection device, the moving object detection unit is direction Within the search area, A boundary line between the dead zone and the rear side scanning area; and An adjacent lane adjacent to the lane in which the host vehicle is traveling Within the area surrounded by A rear side interpolation area is set, and the front side direction Within the survey area , a boundary line between the dead zone and the front-side scanning region; and The above adjacent to the lane in which the vehicle is traveling Adjacent lanes Within the area surrounded by an interpolation area setting unit that sets a front side interpolation area, and based on the movement trajectory of the first target detected within the rear side interpolation area, Passing through the dead zone an estimated trajectory setting unit that sets an estimated trajectory that estimates the movement of the first target to the front side interpolation region; and an estimated first target on the estimated trajectory. 、 The apparatus further includes a target verification unit that compares the estimated first target with the second target and verifies the degree of coincidence between the estimated first target and the second target at the same time. Effect of the Invention

[0011] According to the present invention, the rear direction Within the search area, The boundary between the dead zone and the rear lateral scanning area and Adjacent lanes adjacent to the lane in which the vehicle is traveling Within the area surrounded by Set the posterior side interpolation region, Within the front-side scanning area, a boundary line between the dead zone and the front-side scanning area and The above adjacent to the lane in which the vehicle is traveling Adjacent lanes Within the area surrounded by A front side interpolation area is set, and based on the movement trajectory of the first target detected within the rear side interpolation area, Going through the dead zone An estimated trajectory is set for estimating the movement of the first target to the front-side interpolation region, and the estimated first target on the estimated trajectory is 、 By comparing the estimated first target with the second target to verify the degree of match between the estimated first target and the second target at the same time, it is possible to determine with high accuracy whether the target detected by the rear side sensor and the target detected by the front side sensor are the same, and erroneous detection of the second target can be prevented. [Brief description of the drawings]

[0012] [Figure 1] Schematic diagram of a driving support device [Diagram 2] Functional block diagram of the moving object detection unit [Diagram 3] Flowchart showing an interpolation area setting routine [Figure 4] Flowchart showing an estimated trajectory setting routine [Diagram 5] Flowchart showing target verification routine (part 1) [Figure 6] Flowchart showing target verification routine (part 2) [Figure 7] FIG. 1 is an overhead view showing a state in which a vehicle has entered a dead zone between an interpolation area and a scanning area set on the side of the vehicle. [Figure 8] FIG. 1 is an overhead view showing a state in which a motorcycle has entered a dead zone between an interpolation area and a scanning area set on the side of the vehicle. [Figure 9] FIG. 13 is an overhead view showing a manner in which a reference target is extracted from targets acquired from a following vehicle; [Figure 10] FIG. 1A is a time chart showing a reference target pattern specialized in a change in relative vehicle speed when a following vehicle passes through a rear side interpolation area, and FIG. 1B is a time chart showing an estimated reference target pattern set in a front side interpolation area based on the reference target pattern in FIG. [Figure 11] FIG. 13 is an overhead view showing a manner in which a movement trajectory is compared based on a reference target detected by a front side sensor and a reference target detected by a rear side sensor. [Figure 12] FIG. 13 is an explanatory diagram showing a state in which a moving trajectory is compared with a reference target detected by a front side sensor. [Figure 13] FIG. 11 is an overhead view showing a manner in which a reference object from a following vehicle detected by a front side sensor is verified to be a noise component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Reference symbol M shown in Fig. 7 is a vehicle traveling in a driving lane. Mobile objects traveling in an adjacent lane (overtaking lane) include a vehicle Fa (hereinafter referred to as a "following vehicle") as shown in Fig. 7, and a motorcycle Fb as shown in Fig. 8. Note that this embodiment will be described on the assumption that the road is regulated to keep to the left. Therefore, in the case of a regulation to keep to the right, the left and right will be reversed.

[0014] A driving assistance device 1 shown in Fig. 1 is mounted on the vehicle M. The driving assistance device 1 includes various units such as a driving assistance control unit 11 and a moving object detection unit 12, and the units 11 and 12 are connected to each other for bidirectional communication via an in-vehicle communication line such as a CAN (Controller Area Network). Each of the units 11 and 12 is composed of a microcomputer including a CPU, ROM, RAM, etc., and its peripheral devices, and the ROM stores control programs and fixed data for implementing operations set for each system.

[0015] An input side of the driving assistance control unit 11 is connected to an in-vehicle camera unit 21, a turn signal switch 23 having a left turn switch that is turned on when turning left and a right turn switch that is turned on when turning right, a vehicle speed sensor 24 that detects the vehicle speed (the vehicle's speed), a map locator unit 25, and the like. The in-vehicle camera unit 21 has a stereo camera consisting of a main camera 21a and a sub camera 21b, and an image processing unit (IPU) 22. The cameras 21a and 21b are installed horizontally at equal intervals on the left and right from the center of the vehicle width direction at a position close to the windshield, for example, above the rearview mirror at the front of the vehicle. The in-vehicle camera unit 21 transmits driving environment images of a predetermined imaging area 21A (see Figs. 7 and 8) in front of the vehicle, which are captured by the cameras 21a and 21b, to the driving assistance control unit 11 after predetermined image processing by the IPU 22.

[0016] The map locator unit 25 includes a GNSS (Global Navigation Satellite System) sensor 25a and a road map database 25b. The GNSS sensor 25a receives positioning signals transmitted from a plurality of positioning satellites to acquire the position coordinates of the vehicle. The road map database 25b is a large-capacity storage medium such as an HDD, and stores well-known road map information. The stored road map information includes road types (general roads, trunk roads, expressways, etc.), road shapes, road directions, the number of lanes, lane widths, etc. The driving assistance control unit 11 performs map matching of the position coordinates (latitude, longitude, altitude) acquired by the GNSS sensor 25a on the road map information stored in the road map database 25b, and estimates the vehicle's position (current position) on the road map, and which lane the vehicle is traveling on if multiple lanes are being traveled on.

[0017] A control actuator 31 and an alarm device 32 are connected to the output side of the driving assistance control unit 11. The control actuator 31 is a general term for a power actuator, an electric power steering (EPS) actuator, a brake actuator, and the like, which support the driving state of the host vehicle M. Here, the power actuator controls the output of a drive source such as an engine or an electric motor. The EPS actuator controls the drive of the EPS motor. The brake actuator adjusts the brake hydraulic pressure supplied to the brake wheel cylinders provided on each wheel. Furthermore, the alarm device 32 alerts the driver by using a buzzer sound, voice, monitor display, etc.

[0018] The driving assistance control unit 11 operates a control actuator 31 based on driving environment information from the camera unit 21 to perform various driving assistance controls such as well-known Advanced Emergency Braking (AEB) control, Adaptive Cruise Control (ACC), Active Lane Keep (ALK) control, and Lane Departure Prevention (LDP) control.

[0019] Furthermore, when the driving assistance control unit 11 has an automatic driving function, the driving assistance control unit 11 sets a driving route to a target point set by the driver based on the map locator unit 25, and automatically drives the vehicle through the automatic driving section set on the driving route by operating the control actuator 31. When the driver turns on the turn signal switch 23 to change lanes by operating the steering wheel, if the moving object detection unit 12 described later detects the movement of a moving object approaching from behind or running parallel to the adjacent lane on the side where the lane is to be changed, the driving assistance control unit 11 activates the alarm device 32 to alert the driver.

[0020] On the other hand, a left front side sensor 26 and a right front side sensor 27 as a front side detection section, and a left rear side sensor 28 and a right rear side sensor 29 as a rear side detection section are connected to the input side of the moving body detection section 12. Each of these sensors 26 to 29 is composed of a millimeter wave radar, a microwave radar, a LiDAR (Light Detection and Ranging), or the like. As shown in Fig. 7 and Fig. 8, the left and right front side sensors 26, 27 are disposed, for example, on the left and right ridges of a front bumper, while the left and right rear side sensors 28, 29 are disposed, for example, on the left and right ridges of a rear bumper.

[0021] The front side sensors 26, 27 scan in a fan shape areas (scanning areas) 26A, 27A extending from the left and right diagonally forward to the sides of the vehicle M. On the other hand, the left and right rear side sensors 29, 29 scan in a fan shape areas (scanning areas) 28A, 29A extending from the rear to the left and right of the vehicle M that cannot be scanned by the left and right front side sensors 26, 27.

[0022] 7 and 8, the scanning areas 26A, 28A of the left front side sensor 26 and the left rear side sensor 28, which scan the sides of the vehicle M, and the scanning areas 27A, 29A of the right front side sensor 27 and the right rear side sensor 29, which scan the sides of the vehicle M, respectively, cannot cover all of the left and right sides of the vehicle M due to the sensor characteristics. Therefore, as shown in FIG. 7 and FIG. 8, dead zones (blind spots) Dl, Dr that cannot be scanned are formed between the scanning areas 26A, 28A and between the scanning areas 27A, 29A.

[0023] The scanning areas 26A-29A of the side sensors 26-29 are fan-shaped, and the boundary between the scanning areas 26A, 28A and the dead zone Dl, and the boundary between the scanning areas 27A, 29A and the dead zone Dr intersect at the end of the far side of the scanning. Therefore, the dead zones Dl, Dr in this embodiment are triangular with the side of the vehicle M as the base. Moreover, the dead zones Dl, Dr can be uniquely determined from the installation positions of the side sensors 26-29 relative to the vehicle M and the sensor characteristics. Each of the side sensors 26-29 transmits a transmission wave of a predetermined pulse waveform to the scanning areas 27A-29A and receives the reflected wave.

[0024] As shown in FIG. 2, the moving object detection unit 12 includes the functions of a reference target extraction unit 12a, an interpolation area setting unit 12b, an estimated trajectory setting unit 12c, and a target verification unit 12d.

[0025] The reference target extraction unit 12a samples the reflected waves received by each of the side sensors 26-29 for a predetermined period of time. This sampling interval (t) is set to be longer than the period of one frame in which the reflected waves are received. For example, if the reflected waves are sampled at two-second intervals, eight of them (for 14 seconds) are collected and averaged, and the averaged waveform is set as the average reflected wave. Therefore, the next average reflected wave is calculated by clearing the oldest one of the eight and adding a new one, so this average reflected wave is set at two-second intervals.

[0026] Then, as shown in FIG. 9, the reference target extraction unit 12a extracts, from the received average reflected wave, a target that is closest to the side sensor from which the wave was received, as a reference target (target) T. Then, the round-trip propagation time of the extracted reference target T and the received direction are calculated. Horn? From the vehicle M, target information such as the distance to the reference target T based on the vehicle M, the relative vehicle speed, and position coordinates on a road map is acquired. Note that since the processing in the reference target extraction unit 12a is a known technique, detailed description thereof will be omitted.

[0027] The interpolation area setting unit 12b sets front side interpolation areas Ifl, Ifr and rear side interpolation areas Irl, Irr in lanes (adjacent lanes) adjacent to the host vehicle M. Each of the interpolation areas Ifl, Ifr, Irl, Irr is an area for verifying whether or not a reference target T as a first target extracted in the scanning areas 28A, 29A of the rear side sensors 28, 29 coincides with a reference target T as a second target extracted in the scanning areas 26A, 27A of the front side sensors 26, 27.

[0028] The estimated trajectory setting unit 12c sets, on the time axis, an estimated trajectory Qd that estimates the movement of the reference target T passing through the dead zones Dl, Dr, and an estimated trajectory Q that estimates the movement of the reference target T passing through the front lateral interpolation areas Ifl, Ifr, based on the driving trajectory when the reference target T passes through the rear lateral interpolation areas Irl, Irr.

[0029] The target verification unit 12d compares the reference target T detected in the front side interpolation regions Ifl, Ifr with the estimated trajectory Q to verify whether or not the two match.

[0030] The setting of the interpolation area executed by the interpolation area setting unit 12b of the moving object detection unit 12 is specifically performed according to an interpolation area setting routine shown in Fig. 3. In this routine, first, in step S1, vehicle position information estimated by the map locator unit 25 or estimated based on the driving environment information of the camera unit 21 is read. Next, the process proceeds to step S2, where road map information of the surrounding area is read from the road map database 25b based on the estimated vehicle position.

[0031] Then, the process proceeds to step S3, where information on lanes adjacent to the lane on which the vehicle M is currently traveling (adjacent lanes) is obtained from the road map database 25b or the traveling environment information of the camera unit 21, and rear side interpolation areas Irl, Irr and front side interpolation areas Ifl, Ifr are set for the adjacent lanes. As shown in Figs. 7 and 8, the scanning areas 26A-29A of the side sensors 26-29 set around the vehicle M can be obtained from the characteristics of the side sensors 26-29. Also, the dead zones Dl, Dr can be obtained in advance from the installation positions of the side sensors 26-29 relative to the vehicle M.

[0032] The front and rear directions of the front and side interpolation regions Ifl and Ifr are set from the boundary line of the dead zones Dl and Dr into the scanning regions 26A and 27A, respectively. The front and rear directions of the rear and side interpolation regions Irl and Irr are set from the boundary line of the dead zones Dl and Dr into the scanning regions 28A and 29A, respectively.

[0033] Therefore, the boundary lines of the dead zones Dl, Dr, the boundary lines of the rear side interpolation areas Irl, Irr, and the boundary lines of the front side interpolation areas Ifl, Ifr are stored in advance in position coordinates based on the host vehicle M. height For example, as shown in Fig. 9, position coordinates are set with the center of the vehicle M as the origin, the front-rear direction as the x-axis, and the vehicle width direction as the y-axis. Note that the front boundary line of the front side interpolation areas Ifl, Ifr and the rear boundary line of the rear side interpolation areas Irl, Irr are each set at a position several meters ahead of the front-rear length of the vehicle M.

[0034] On the other hand, the width direction of the adjacent lane is obtained and set from road map information. In this case, in step S2, the driving environment information from the camera unit 22 may be read, and in step S3, the lane width of the adjacent lane may be obtained from the driving environment information.

[0035] Therefore, in step S3, the lateral interpolation areas Ifl, Ifr, Irl, and Irr are set in the areas surrounded by the front-to-rear boundaries of each lateral interpolation area Ifl, Ifr, Irl, and Irr, which are stored in advance, and the left-to-right boundaries set based on the section line information of the adjacent lane, as shown by hatching in Figures 7 and 8, and the routine ends.

[0036] The estimated trajectory set by the estimated trajectory setting unit 12c is set according to an estimated trajectory setting routine shown in Fig. 4. This routine is executed in synchronization with the sampling interval (t) of the reference target extraction unit 12a. First, in step S11, it is checked from the reference target T stored in the reference target extraction unit 12a whether or not the reference target T exists in at least one of the left and right rear side interpolation areas Irl, Irr. If the reference target T exists in at least one of the left and right rear side interpolation areas Irl, Irr, the process proceeds to step S12. If the reference target T does not exist in either of the left and right rear side interpolation areas Irl, Irr, the process exits the routine.

[0037] In addition, since the determination of whether or not a reference target T extracted from a target detected by the left front lateral sensor 26 matches the estimated trajectory Q and the determination of whether or not a reference target T extracted from a target detected by the right front lateral sensor 27 matches the estimated trajectory Q are the same process, in the following, they will be described collectively as the front lateral sensors (26, 27), the front lateral interpolation regions (Ifl, Ifr), and the dead zones (Dl, Dr).

[0038] In step S12, the reference object T is plotted at coordinates on a road map, a reference object pattern in time series is stored, and the process proceeds to step S13. The reference object T is set based on the object having the closest distance to the rear side sensor (28, 29) from which the signal was received. Therefore, as shown in FIG. 9, for example, consider a situation in which a following vehicle Fa, which is a moving body traveling in an adjacent lane to the right of the lane in which the host vehicle M is traveling, approaches the host vehicle M from behind and attempts to overtake the host vehicle M.

[0039] In this case, the following vehicle Fa first enters the scanning area 29A of the right rear side sensor 29 (Fa(0)), then enters the rear side interpolation area Irr (Fa(1)). After that, it passes through the dead zone Dr (Fa(2)), and enters the front side interpolation area Ifr and the scanning area 27A of the right front side sensor 27 (Fa(3)). After that, it leaves the front side interpolation area Ifr, and further leaves the scanning area 27A of the right front side sensor 27 (Fa(4)).

[0040] When the following vehicle Fa enters the scanning area 29A and reaches the vicinity of the side of the right rear side sensor 29, a target near the left ridge of the front of the following vehicle Fa is extracted as the reference target T. After the front of the following vehicle Fa reaches the side of the right rear side sensor 29, while the following vehicle Fa passes the side of the right rear side sensor 29, the side of the following vehicle Fa is closest to the right rear side sensor 29.

[0041] Therefore, the reference target extraction unit 12a extracts a target whose side is detected as a reference target T from among the targets detected by the right rear side sensor 29. Then, when the rear of the following vehicle Fa passes beside the right rear side sensor 29, the reference target extraction unit 12a extracts a target whose left ridge portion near the rear of the following vehicle Fa is detected as a reference target T from among the targets detected by the right rear side sensor 29.

[0042] For example, Fig. 10(a) shows a schematic diagram of a reference target pattern representing a change in the relative vehicle speed ΔVx [m / sec] in the longitudinal direction obtained from the reference target T when the following vehicle Fa attempts to overtake the host vehicle M, enters the rear side interpolation area Irr, and exits the dead zone Dr. For simplicity of explanation, it is assumed here that the following vehicle Fa maintains a constant lateral distance (lateral position) from the host vehicle M and maintains a constant relative vehicle speed. Therefore, the following explanation assumes that the relative vehicle speed ΔVy in the lateral direction is 0 [m / sec].

[0043] As shown in the figure, when the following vehicle Fa enters the rear side interpolation area Irr and approaches the right rear side sensor 29 from behind, the reference target extraction unit 12a extracts the front side of the following vehicle Fa as the reference target T until the front of the following vehicle Fa reaches the side of the right rear side sensor 29. Therefore, the relative vehicle speed ΔVx in the forward / rearward direction from the reference target T can be detected.

[0044] While the side of the following vehicle Fa passes beside the right rear side sensor 29, the relative vehicle speed ΔVx is approximately 0 [m / sec]. Therefore, the correct relative vehicle speed ΔVx is not detected from the reference object T. In this case, the position coordinates of the following vehicle Fa are naturally fixed at approximately the same position.

[0045] Thereafter, as the rear of the following vehicle Fa reaches the lateral direction of the right rear side sensor 29 and then moves away, the reference target extraction unit 12a extracts the rear side of the following vehicle Fa as the reference target T, and the relative vehicle speed ΔVx in the longitudinal direction is detected again.

[0046] Then, the process proceeds to step S13, where it is determined whether or not the reference target T extracted by the reference target extraction unit 12a from among the targets detected by the rear side sensors (28, 29) has reached the boundary line of the dead zone (Dl, Dr). If the reference target T has not reached the boundary line, the process exits the routine. On the other hand, if the reference target T has reached the boundary line, the process proceeds to step S14. Whether or not the reference target T has reached the boundary line is determined by, for example, comparing the position coordinates of the reference target T based on the host vehicle M with the position coordinates of a preset boundary line.

[0047] In step S14, an estimated trajectory Qd passing through the dead zone (Dl, Dr) is set based on the reference target T immediately before it exits the rear side interpolation region (Irl, Irr), that is, the reference target T extracted from the rear side of the following vehicle Fa as described in Fig. 10(a) above, and the process proceeds to step S15. Note that in this estimated trajectory Qd, position coordinates (x1, y1) for estimating the movement of the estimated reference target in synchronization with the sampling interval (t) of the reference target extraction unit 12a and the vehicle speed (Vx1, Vy1) at that time are stored.

[0048] Therefore, the position coordinates and relative vehicle speed of a target moving within the dead zone (Dl, Dr) are estimated based on this estimated trajectory Qd. Therefore, even if, for example, a motorcycle Fb shown in Fig. 8 has a short front-to-rear length and enters the dead zone (Dl, Dr) entirely while overtaking the host vehicle M and cannot be detected by the side sensors (26, 27), (28, 29), the moving body (motorcycle Fb) moving within the dead zone (Dl, Dr) can be estimated based on the estimated trajectory Qd.

[0049] In step S15, an estimated trajectory Qn of the reference target pattern continuing from the estimated trajectory Qd set in step S14 is set based on the target data indicating the reference target pattern until the reference target T exits the rear side interpolation region (Irl, Irr) described in FIG. 10(a). Furthermore, an estimated trajectory Qf continuing from the estimated trajectory Qn is set, and the routine ends. Note that this estimated trajectory Qf is set based on the estimated trajectory Qd passing through the dead zone (Dl, Dr). Furthermore, the estimated trajectories Qn and Qf store the position coordinates (x1, y1) for estimating the movement of the estimated reference target and the vehicle speed (Vx1, Vy1) at that time in synchronization with the sampling interval (t) of the reference target extraction unit 12a (see FIG. 12).

[0050] As shown in FIG. 10(b), when the following vehicle Fa leaves the dead zone (Dl, Dr) and enters the front side interpolation region (Ifl, Ifr), the following vehicle Fa passes the host vehicle M and moves forward, so that the estimated trajectory Qn becomes a pattern opposite to the reference target pattern shown in FIG. 10(a) described above. Therefore, based on the estimated reference target pattern exemplified in FIG. 10(b), the estimated trajectory Qn of the following vehicle Fa passing through the front side interpolation region (Ifl, Ifr) is set. Therefore, the above-mentioned estimated trajectory Q is a collective term for the estimated trajectories Qn and Qf.

[0051] In addition, the moving object detection unit 12 outputs the estimated reference object based on the estimated trajectories Qd, Q to the driving assistance control unit 11 as reference object data until the target verification unit 12d described later verifies that the reference object T detected in the front side interpolation region (Ifl, Ifr) and the reference object T extracted in the rear side interpolation region (Irl, Irr) are identical.

[0052] Moreover, the verification of whether the reference target T detected in the rear side interpolation region (Irl, Irr) coincides with the reference target T detected in the front side interpolation region (Ifl, Ifr), which is executed by the target verification unit 12d, is specifically performed according to a target verification routine shown in FIG. 5 and FIG. 6.

[0053] In this routine, first, in step S21, it is determined whether or not the estimated reference object of the estimated trajectory Q has entered the front side interpolation region (Ifl, Ifr) from the dead zone (Dl, Dr) based on the position coordinates (x1, y1) for estimating the movement of the estimated reference object.

[0054] Then, if the intrusion of the estimated trajectory Q (estimated reference object) is detected, the process proceeds to step S22. If the intrusion of the estimated trajectory Q (estimated reference object) is not yet detected, the process exits the routine.

[0055] When the process proceeds to step S22, a lane change warning command to the adjacent lane on the side on which the estimated trajectory Q is detected is output to the driving assistance control unit 11, and the process proceeds to step S23.

[0056] When the driving assistance control unit 11 receives a lane change warning command from the moving object detection unit 12 for the adjacent lane on the side where the entry of the estimated trajectory (estimated reference object) Q has been detected, if the driving assistance control unit 11 detects an operation by the driver to change lanes to the adjacent lane that is the target of the lane change warning command, it activates the notification device 32 to warn the driver. For example, if the operation to change lanes is the ON of the turn signal switch 23 and the driver turns ON the switch on the adjacent lane that is the target of the lane change warning command, the driving assistance control unit 11 activates the notification device 32 to notify the driver that the moving object identified by the estimated trajectory Q is traveling in the adjacent lane, or that there is a possibility that a moving object is traveling there.

[0057] Thereafter, the process proceeds to step S23, where the degree of coincidence between the estimated reference object of the estimated trajectory Q and the reference object T extracted by the reference object extracting unit 12a on the same time axis is examined.

[0058] For example, as shown in FIG. 11, when the following vehicle Fa is traveling in the adjacent lane on the right side, an estimated trajectory Q in the right front side interpolation area Ifr is set based on the traveling trajectory detected in the right rear side interpolation area Irr. Then, the movement of the following vehicle Fa in the right front side interpolation area Ifr is estimated based on this estimated trajectory Q. Meanwhile, it is assumed that the reference target extraction unit 12a extracts reference targets T(0) to T(6) in the right front side interpolation area Ifr in time series at each sampling interval based on the targets detected by the right front side sensor 27. Then, the estimated reference targets of the estimated trajectory Q are successively compared with the reference targets T(0) to T(6) at the same time to check the degree of agreement.

[0059] An example of how to calculate the degree of coincidence will be given below. As shown in Fig. 12, the estimated reference object at the same time is Q(t) and the reference object is T(t). The position coordinates of the estimated reference object Q(t) are (x1, y1) and the relative vehicle speed is (ΔVx1, ΔVy1). The position coordinates of the reference object T(t) are (x1', y1') and the relative vehicle speed is (ΔVx1', ΔVy1').

[0060] First, the deviation width ΔL in the straight-line distance of the position coordinates of each target Q(t) and T(t) is calculated from the mean square shown in equation (1), and the relative deviation width ΔL of each target Q(t) and T(t) is calculated from the mean square shown in equation (1). Vehicle speed The velocity vector Pv is calculated from the root mean square shown in equation (2).

[0061]

number

[0062] Here, α and β are weighting coefficients set for ΔL and Pv, and the ratio between the two is set appropriately depending on the situation (α=1−β).

[0063] And the deviation width ΔL of the position coordinates and the relative Vehicle speed The matching level Lv is calculated by adding the velocity vector Pv of the position coordinates to the position coordinates (Lv = ΔL + Pv). Vehicle speed The smaller the value of the velocity vector Pv, the higher the degree of match.

[0064] For example, if the position coordinates of the estimated reference object Q(t) and the reference object T(t) are separated by (x=2[m], y=2[m]), then ΔL is approximately 1.4[m] when the weighting coefficient α is 0.5.

[0065] For example, if the relative vehicle speed of the estimated reference object Q(t) is (ΔVx1=10[m / sec], ΔVy1=0) and the relative vehicle speed of the reference object T(t) is (ΔVx1=12[m / sec], ΔVy1'=0), and if the weighting coefficient β is 0.5, the velocity vector Pv will be 1[m / sec] in the x-axis direction. Therefore, Lv ≈ 2.4.

[0066] The value of this matching level Lv changes depending on the ratio of the weighting factors α and β. Therefore, the matching level can be given a certain degree of freedom by using the weighting factors α and β.

[0067] Next, the process proceeds to step S24, where the coincidence level Lv is compared with a coincidence determination threshold Lo. This coincidence determination threshold Lo is a value for determining whether or not the estimated reference object Q(t) and the reference object T(t) coincide with each other, and is previously determined and set through experiments or the like, but can be variably set as desired.

[0068] If Lv≦Lo, it is determined that the estimated reference object Q(t) and the reference object T(t) at the same time coincide with each other, and the process proceeds to step S25, where the count value C of the coincidence counter is incremented (C←C+1), and the process proceeds to step S26. If Lv>Lo, it is determined that the estimated reference object Q(t) and the reference object T(t) at the same time do not coincide with each other, and the process exits the routine.

[0069] When proceeding to step S26, it is examined whether the estimated trajectory Q has exited the front-side interpolation region (Ifl, Ifr). Whether it has exited or not is determined by comparing the position coordinates of the estimated trajectory Q advancing in time series with the position coordinates of a boundary line preset on the exit side of the front-side interpolation region (Ifl, Ifr). If it is determined that the estimated trajectory Q has exited the front-side interpolation region (Ifl, Ifr), proceed to step S27. Also, if it is determined that the estimated trajectory Q is within the front-side interpolation region (Ifl, Ifr), exit the routine.

[0070] When proceeding to step S27, it is examined whether the count value C of the match counter is equal to or greater than the reliability determination threshold Co. And when C≥Co, it is determined that the reliability of the reference target T extracted based on the target detected by the front-side sensors (26, 27) is high, and proceed to step S28. Also, when C<Co, it is determined that the reference target T has a high possibility of false detection, and branches to step S29.

[0071] In step S28, the verification result that the reference target T detected in the front-side interpolation region (Ifl, Ifr) is the same as the reference target T extracted in the rear-side interpolation region (Irl, Irr) is memorized and proceed to step S31. For example, as shown in FIG. 11, when comparing the reference target T(0) to T(6) at the same time as the estimated reference target Q (not shown) of the estimated trajectory Q, it is assumed that the matching level Lv of the reference targets T(0), T(2), T(5), T(6) is determined to be a match with Lv≤Lo, and the matching level Lv of the reference targets T(1), T(3), T(4) is determined to be a mismatch exceeding Lo. In this case, if Co is set to 4, even if a noise component is superimposed on the reference targets T(1), T(3), T(4) and an unstable value is temporarily detected, it is verified that the reference target T detected in the front-side interpolation region (Ifl, Ifr) is the same as the reference target T extracted in the rear-side interpolation region (Irl, Irr).

[0072] In step S28, if it is verified that the reference target T detected in the front side interpolation region (Ifl, Ifr) is identical to the reference target T extracted in the rear side interpolation region (Irl, Irr), the moving body detection unit 12 extracts the data (position coordinates, relative Vehicle speed ) to the driving assistance control unit 11. The driving assistance control unit 11 performs appropriate driving assistance when changing lanes, etc., based on the obtained data of the reference object T.

[0073] Also, when the process branches to step S29, a verification result that the reference target T detected in the front side interpolation region (Ifl, Ifr) is a false positive is stored, and the process proceeds to step S30. In step S30, the data of the reference target T extracted in the front side interpolation region (Ifl, Ifr) is cleared, and the process proceeds to step S31.

[0074] 13, when a following vehicle Fa, which is a moving object traveling in an adjacent lane, changes lanes from a dead zone Dr to a right-turn lane, the targets detected by the front lateral sensor 27 are clearly noise components, and therefore the reference targets T(0) to T(2) extracted from these noise components are clearly erroneous detections. In this case, if the reference targets T(0) to T(2) are not compared with the estimated reference target Q(t) of the estimated trajectory Q at the same time, it cannot be clearly determined whether the reference targets T(0) to T(2) actually exist or not.

[0075] In the above-mentioned step S30, the erroneously detected reference object T is cleared, so that it is possible to prevent erroneous detection of the following vehicle Fa based on the erroneous reference object T. In this case, the objects detected by the front side sensors 26, 27 are determined to be noise components until a new estimated trajectory Q is set in the estimated trajectory setting unit 12c.

[0076] Thereafter, when proceeding to step S28 or step S31 from step S30, the data of the estimated trajectory Q is cleared and the process proceeds to step S32. Therefore, if it is verified in step S28 that the reference object T is a moving object, both the estimated trajectory Q and the reference object T are held until they exit the front side interpolation region (Ifl, Ifr). On the other hand, if it is verified in step S29 that the reference object T detected in the front side interpolation region (Ifl, Ifr) is a false detection, only the estimated trajectory Q is held until they exit the front side interpolation region (Ifl, Ifr).

[0077] Therefore, as shown in FIG. 13, even if the following vehicle Fa changes lanes to a right-turn lane, the driving assistance control unit 11 continues to issue a lane change warning command to the adjacent lane on the side where the estimated trajectory Q is detected until the estimated reference object Q(t) of the estimated trajectory Q exits the front lateral interpolation region (Ifl, Ifr).

[0078] When the process proceeds to step S32, since the estimated trajectory Q has left the front lateral interpolation region (Ifl, Ifr), a lane change warning cancellation command for the adjacent lane on the side on which the estimated trajectory Q was detected is output to the driving assistance control unit 11, and the process proceeds to step S33, where the count value C of the coincidence counter is cleared (C←0), and the routine is exited.

[0079] In addition, after it is verified that the reference object T detected in the front-side interpolation region (Ifl, Ifr) is from the moving object (the following vehicle Fa) and the estimated reference object Q(t) of the estimated trajectory Q leaves the front-side interpolation region (Ifl, Ifr), the reference object T is extracted based on the values ​​detected by the front-side sensors (26, 27).

[0080] In this manner, according to the present embodiment, the front side interpolation areas Ifl, Ifr and the rear side interpolation areas Irl, Irr are set on both sides of the dead zone Dl.Dr formed between the scanning areas 26A, 27A of the front side sensors 26, 27 and the scanning areas 28A, 29A of the rear side sensors 28, 29 provided on the vehicle M, and an estimated trajectory Qd passing through the dead zone Dl.Dr is set based on the reference object T detected in the rear side interpolation area Irl, Irr, and the moving objects Fa, Fb moving through the dead zone Dl.Dr are estimated based on this estimated trajectory Qd. As a result, even if the moving objects Fa, Fb pass through the dead zone Dl.Dr, appropriate driving assistance such as alerting the driver can be performed.

[0081] Furthermore, an estimated trajectory Q is set to estimate the trajectory of the reference target passing through the front-side interpolation area Ifl, Ifr based on the reference target T detected in the rear-side interpolation area Irl, Irr, and the degree of coincidence between the estimated trajectory Q and the reference target T detected by the front-side sensors 26, 27 at the same time is examined to determine whether this reference target T is identical to the one detected by the rear-side sensors 28, 29 or a noise component. Therefore, it is possible to determine with high accuracy whether the reference target T detected by the rear-side sensors 28, 29 is identical to the reference target T detected by the front-side sensors 26, 27, and to prevent erroneous detection.

[0082] Incidentally, the present invention is not limited to the above-described embodiment. For example, when the vehicle M is traveling in autonomous driving mode, when the driving assistance control unit 11 receives a lane change caution command in step S22, lane changes are prohibited until the command is released. [Explanation of symbols]

[0083] 1...Driving assistance device, 11... Driving assistance control unit, 12...moving object detection unit, 12a...Reference target extraction unit, 12b...Interpolation area setting unit, 12c...Estimated trajectory setting section, 12d…Target verification section, 21...In-vehicle camera unit, 21A...imaging area, 21a…Main camera, 21b…Sub camera, 22...Camera unit, 23...Wind signal switch, 24...Vehicle speed sensor, 25…Map locator unit, 25a…GNSS sensor, 25b…Road map database, 26...Left front side sensor, 27…Right front side sensor, 28...Left rear side sensor, 29…Right rear side sensor, 29...Right and left rear side sensors, 26A to 29A: Scanning area, 31...Control actuator, 32...Alarm device, C: Count value, Co: confidence threshold, Dl, Dr: dead zone, Fa…Following vehicle, Fb: Motorcycle, Ifl: left anterior lateral interpolation area, Ifr…right front lateral interpolation area, Irl: left anterior lateral interpolation area, Irr: Right rear side interpolation area, Lo: Matching threshold value, Lv...Match level, M…own vehicle, Pv...velocity vector, Q, Qd, Qf, Qn...Estimated trajectory, Q(t)…Estimated reference target, T...Reference target, ΔL: deviation width, ΔVx, ΔVy: relative vehicle speed, α,β…Weighting coefficients

Claims

1. a rear side detection unit that scans the rear side of the host vehicle to detect a first target; a front side detection unit that scans a front side of the host vehicle to detect a second target; a moving object detection unit that detects, based on each of the targets detected by the rear side detection unit and the front side detection unit, a movement of a moving object identified by the target; Equipped with In a moving object detection device for a vehicle, a dead zone that cannot be scanned is formed between a rear-side scanning area scanned by the rear-side detection unit and a front-side scanning area scanned by the front-side detection unit, The moving object detection unit is an interpolation area setting unit which sets a rear side interpolation area within the rear side scanning area, the rear side interpolation area being surrounded by a boundary line between the dead zone and the rear side scanning area and an adjacent lane adjacent to the lane on which the host vehicle is traveling, and sets a front side interpolation area within the front side scanning area, the front side interpolation area being surrounded by a boundary line between the dead zone and the front side scanning area and an adjacent lane adjacent to the lane on which the host vehicle is traveling; an estimated trajectory setting unit that sets an estimated trajectory for estimating a movement of the first target passing through the dead zone into the front-side interpolation region based on a movement trajectory of the first target detected within the rear-side interpolation region; a target verification unit that compares an estimated first target on the estimated trajectory with the second target and verifies a degree of coincidence between the estimated first target and the second target at the same time. A moving object detection device for a vehicle.

2. The target verification unit determines the degree of coincidence based on position coordinates of the estimated first target and the second target.

2. The moving object detection device for a vehicle according to claim 1.

3. The target verification unit determines the degree of coincidence based on a relative vehicle speed of the estimated first target with respect to the host vehicle and a relative vehicle speed of the second target with respect to the host vehicle.

2. The moving object detection device for a vehicle according to claim 1.

4. 2. The moving object detection device for a vehicle according to claim 1, wherein the target verification unit determines the degree of match based on a value obtained by adding a root mean square of a difference in position coordinates between the estimated first target and the second target and a root mean square of a difference in a relative vehicle speed of the estimated first target with respect to the host vehicle and a relative vehicle speed of the second target with respect to the host vehicle.

5. The target verification unit determines that the estimated first target and the second target match when the degree of match is lower than a preset determination threshold value, counts the number of times that the estimated first target and the second target are determined to match in the front-side interpolation region, and verifies that the second target and the first target are identical when the count value is equal to or greater than a predetermined value.

5. The moving object detection device for a vehicle according to claim 1.

6. When the target verification unit verifies that the first target and the second target are identical, the target verification unit holds both the data of the estimated trajectory and the data of the second target until the estimated first target and the second target exit the front side interpolation region.

6. The moving object detection device for a vehicle according to claim 5.

7. When the target verification unit verifies that the first target and the second target are different, the target verification unit holds only the data of the estimated trajectory until the estimated first target exits the front side interpolation area, and warns the driver about changing lanes to the adjacent lane on the side where the estimated trajectory is detected.

6. The moving object detection device for a vehicle according to claim 5.

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