WO2017199971A1

WO2017199971A1 - Vehicle control device and vehicle control method

Info

Publication number: WO2017199971A1
Application number: PCT/JP2017/018409
Authority: WO
Inventors: 高木　亮
Original assignee: 株式会社デンソー
Priority date: 2016-05-19
Filing date: 2017-05-16
Publication date: 2017-11-23

Abstract

An ECU (20) carries out a collision avoidance control to avoid a collision with an object on the basis of first information which is a result of a detection of the object based on reflected waves which correspond to transmitted waves, and/or of second information which is a result of a detection of the object based on a captured image of the view ahead of a vehicle which is captured with an image capture means. If a state in which the object is detected by the first information and the second information has transitioned to a state in which the object is detected by only the first information, the ECU (20) assesses whether the object is located in a proximity region which is predetermined as a region ahead of the vehicle in which the second information cannot be acquired. If it is assessed that the object is located in the proximity region, the ECU (20) maintains an operation condition of the collision avoidance control from the state in which the object is detected by the first information and the second information.

Description

Vehicle control apparatus and vehicle control method

Cross-reference of related applications

This application is based on Japanese Application No. 2016-10000809 filed on May 19, 2016 and Japanese Application No. 2016-225193 filed on November 18, 2016. Is used.

The present disclosure relates to a vehicle control device and a vehicle control method for detecting an object positioned in front of the vehicle.

A technique for synthesizing a detection result of an object based on a reflected wave corresponding to a transmission wave and a detection result of an object acquired by an image sensor and generating new information (fusion target) on the object is known. The recognition accuracy of the object ahead of the vehicle can be improved by the generated fusion target. Further, by using the position information and the object width of the object specified using this information, it is possible to appropriately perform the collision avoidance control of the vehicle when avoiding the collision with the object.

It is known that the detection result of the object acquired by the image sensor is unstable compared to the detection result of the object based on the reflected wave. For example, the image sensor may not be able to detect an object existing in front of the vehicle due to the dark surroundings of the vehicle. Hereinafter, a state where an object cannot be detected by the image sensor is referred to as an image lost. Therefore, Patent Document 1 discloses a vehicle control device that continues collision avoidance control based on the detection result of an object by a radar sensor when an image lost occurs after a fusion target is generated. In this vehicle control device, after the image is lost, the detection accuracy of the object is lowered, so that the collision avoidance control is difficult to operate.

JP 2007-226680 A

By the way, the image lost may be caused by the proximity of the object and the vehicle, in addition to the image lost due to the brightness around the vehicle. Specifically, when the object and the vehicle are close to each other, the object deviates from the angle of view of the image sensor, and the image sensor cannot detect the object properly, and image loss occurs. If it is difficult to operate the collision avoidance control when image loss occurs due to the proximity of the object and the vehicle, there is a high possibility that the collision avoidance control may be delayed or deactivated.

The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a vehicle control device and a vehicle control method capable of suppressing the operation delay and inactivity of the collision avoidance control.

In the present disclosure, the first information that is the detection result of the object based on the reflected wave corresponding to the transmission wave and the second information that is the detection result of the object based on the captured image obtained by capturing the front of the vehicle with the imaging unit are used. A vehicle control device that detects the object, and a controller that performs collision avoidance control for avoiding a collision with the object based on at least one of the first information and the second information; When the object transitions from the state detected by the first information and the second information to the state detected only by the first information, the object acquires the second information in front of the vehicle. A position determination unit that determines whether or not the object is located in a nearby region that is determined in advance as a region that cannot be determined; and the collision determination unit determines that the object is located in the vicinity region by the position determination unit. A vehicle control device comprising a maintaining unit for maintaining the operating conditions of the avoidance control from a state where the object is detected by the first information and the second information.

In the disclosure configured as described above, when the object transitions from the state detected by the first information and the second information to the state detected only by the first information, the position of the object is in the vicinity in front of the vehicle. If it is located in the region, the operating condition of the collision avoidance control is maintained. With the above-described configuration, even when an image is lost due to the object entering the vicinity region, it is possible to suppress the operation delay or inactivation of the collision avoidance control for the object.

The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing
FIG. 1 is a block diagram of PCSS. FIG. 2A is a diagram illustrating a position of an object detected by an image sensor and a radar sensor, FIG. 2B is a diagram illustrating a position of an object detected by the image sensor and the radar sensor. FIG. 3 is a diagram for explaining the PCS. FIG. 4A is a diagram for explaining factors that cause image loss. FIG. 4B is a diagram for explaining factors that cause image loss. FIG. 5 is a flowchart for explaining the PCS. FIG. 6 is a diagram illustrating the neighborhood area NA. FIG. 7 is a diagram for explaining detailed processing performed in step S19 of FIG. FIG. 8A is a diagram for explaining changes in the operability of the PCS. FIG. 8B is a diagram for explaining changes in the operability of the PCS; FIG. 8C is a diagram for explaining changes in the operability of the PCS. FIG. 9 is a flowchart showing the process performed in step S19 in the second embodiment. FIG. 10A is a diagram for explaining the movement of an object in the vicinity area NA. FIG. 10B is a diagram for explaining the movement of the object in the vicinity area NA. FIG. 11 is a diagram for explaining the position of the neighborhood region in the third embodiment. FIG. 12 is a flowchart showing the process performed in step S14 of FIG. 5 in the third embodiment. FIG. 13 is a diagram for explaining the center position and the object width. FIG. 14 is a flowchart showing the process performed in step S18 of FIG. 5 in the third embodiment. FIG. 15 is a diagram for explaining the predicted value of the center position. FIG. 16 is a diagram for explaining the left and right end angles. FIG. 17 is a diagram for explaining the discontinuity reliability.

Hereinafter, each embodiment will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are denoted by the same reference numerals in the drawings, and the description of the same reference numerals is used.

(First embodiment)
The vehicle control device and the vehicle control method according to the present embodiment are mounted on a vehicle (host vehicle CS), detect an object existing in front of the host vehicle CS, and avoid or reduce a collision with the object. It is realized by PCSS (Pre-crash safety system) that performs various controls. In FIG. 1, the PCSS 100 includes a driving assistance ECU 20 (hereinafter referred to as ECU 20), various sensors 30, and a controlled object 40. In FIG. 1, the ECU 20 functions as a vehicle control device.

The various sensors 30 are connected to the ECU 20 and output detection results for the object and the host vehicle CS to the ECU 20. In FIG. 1, the PCSS 10 includes an image sensor 31, a radar sensor 32, a vehicle speed sensor 33, and a turning motion detection sensor 34 as various sensors 30.

The image sensor 31 is a CCD camera, a monocular camera, a stereo camera or the like, and is installed near the upper end of the windshield of the host vehicle CS. The image sensor 31 captures a captured image by capturing an area that extends in a predetermined range toward the front of the host vehicle CS at predetermined time intervals. Then, by processing the captured image, the position and orientation of the object ahead of the host vehicle CS are acquired as image information and output to the ECU 20. Hereinafter, an object whose image information is detected by the image sensor 31 is also referred to as an image target IT. In this embodiment, the image sensor 31 functions as an imaging unit.

As shown in FIG. 2A, the image information includes the position of the image target IT on the coordinates specified by the vehicle traveling direction (Y axis) and the lateral direction (X axis) with the host vehicle CS as a reference position. include. In FIG. 2A, the image information includes left and right lateral positions Xr, Xl in the lateral direction (X axis) of the image target IT, and an azimuth angle θc indicating the azimuth from the host vehicle CS to the object Ob. The ECU 20 can calculate the object width WO from the lateral positions Xr and Xl of the image target IT.

The radar sensor 32 acquires radar information that is a detection result of an object based on a reflected wave corresponding to the transmission wave. The radar sensor 32 is attached at the front of the host vehicle CS so that its optical axis faces the front of the vehicle (Y-axis direction), and scans the front of the vehicle by transmitting a transmission wave toward the front of the vehicle. At the same time, the reflected wave reflected from the surface of the object with respect to the transmitted wave is received. Then, radar information indicating the distance to the object, the relative speed with the object, and the like is generated according to the reflected wave. As the transmission wave, a directional electromagnetic wave such as a millimeter wave can be used.

As shown in FIG. 2B, the radar information includes the position of the radar target RT in the vehicle traveling direction (Y axis) relative to the host vehicle CS and the azimuth angle θr from the host vehicle CS to the radar target RT. included. Based on the position of the radar target RT in the vehicle traveling direction (Y-axis), the ECU 20 sets the relative distance Dr, which is the distance on the Y-axis from the host vehicle CS to the radar target RT, and the relative distance Dr. Based on this, the relative speed Vr of the radar target RT with reference to the host vehicle CS can be acquired. In this embodiment, radar information functions as first information, and image information functions as second information.

The vehicle speed sensor 33 is provided on a rotating shaft that transmits power to the wheels of the host vehicle CS, and calculates the vehicle speed that is the speed of the host vehicle CS based on the rotation speed of the rotating shaft.

The turning motion detection sensor 34 detects the turning angular velocity of the host vehicle CS that changes from the vehicle traveling direction. For example, the turning motion detection sensor 34 includes a yaw rate sensor that detects a turning angular velocity of the host vehicle CS and a steering angle sensor that detects a steering angle by a steering device (not shown). Based on the output from the turning motion detection sensor 34, the ECU 20 can determine whether or not the host vehicle CS is making a turning motion.

The ECU 20 is configured by a known microcomputer and includes a CPU, a ROM, a RAM, and the like. ECU20 functions as the position acquisition part 21, the control part 22, the position determination part 23, and the maintenance part 24 by running the program memorize | stored in ROM. First, PCS (collision avoidance control) performed by the ECU 20 will be described.

The position acquisition unit 21 acquires position information of an object ahead of the host vehicle from image information that is an object detection result by the image sensor 31 or radar information that is an object detection result by the radar sensor 32.

When the control unit 22 acquires image information and radar information for the same object, the control unit 22 fuses the image information and the radar information, so that fusion information that is new position information for the object is obtained. Is generated. For example, the relative distance Dr based on the radar information is set as the position of the object in the traveling direction (on the Y axis) of the host vehicle CS, and the horizontal position based on the image information is set as the position of the object in the horizontal direction (on the X axis) Generate fusion information. As described above, when generating fusion information for an object, information on the object is generated using information with higher accuracy among the information acquired by the radar sensor 32 and the image sensor 31, and recognition of the object is performed. Accuracy can be improved. Hereinafter, an object for which fusion information is generated is referred to as a fusion target FT.

And the control part 22 determines the collision possibility of the object which detected the positional information, and the own vehicle CS, and controls the action | operation of PCS based on the determined collision possibility. For example, the control unit 22 determines the possibility that the host vehicle CS and the object collide based on a lap rate RR that is a ratio in which the object width WO and the determination region Wcd overlap in the X-axis direction. Based on this, the operation of the PCS is controlled. Here, the determination area Wcd is an area virtually set in front of the host vehicle CS.

When the lap rate RR is equal to or greater than a predetermined value, as shown in FIG. 3, the collision margin time TTC (Time to Collision) for the object is calculated by a method such as dividing the relative distance Dr by the relative speed Vr with the object. . The TTC is an evaluation value indicating how many seconds later the vehicle collides with an object when traveling at the vehicle speed as it is. The smaller the TTC, the higher the risk of collision, and the larger the TTC, the higher the risk of collision. The nature becomes low. In FIG. 3, the values decrease in the order of TTC1, TTC2, and TTC3. The control unit 22 compares the calculated current TTC with the TTC set for each controlled object 40, and activates the corresponding controlled object 40 when the corresponding controlled object 40 exists.

1 includes an alarm device 41, a seat belt device 42, and a brake device 43 as controlled objects 40, and a predetermined operation timing (TTC) is set for each controlled object 40. Therefore, the ECU 20 compares the TTC and the operation timing of each controlled object 40, and activates the controlled object 40 when the TTC corresponds to the operation timing of each controlled object 40.

For example, if TTC is the operation timing of the alarm device 41, an alarm is transmitted to the driver by the operation of the alarm device 41. When TTC is the operation timing of the seat belt device 42, the seat belt device 42 is controlled to be wound up. If TTC is the operation timing of the brake device 43, the automatic brake is operated to control to reduce the collision speed. Thus, the collision between the host vehicle CS and the object is avoided or alleviated.

Also, after generating the fusion information, the control unit 22 changes the operating conditions of the PCS under certain conditions when image information is not detected and image loss occurs. Once the object is recognized as the fusion target FT, the reliability of existing in front is high. Therefore, even after the object is no longer recognized as the fusion target FT, it is preferable that the PCS for the object can be continued instead of being excluded from the PCS target. Therefore, when image loss occurs after the fusion information is generated, the PCSS 100 continues the PCS based on the radar information and the past object width WO. On the other hand, when the image lost occurs, the image target IT cannot be acquired from the image sensor 31, and the object width WO cannot be newly acquired. Therefore, after the image has been lost, the past object width WO in which the fusion target FT has been detected is used, and the operating condition is changed so that the PCS becomes difficult to operate under a certain condition by reducing the object width WO. And it corresponds to the decrease in detection accuracy.

As shown in FIG. 4A, the object detection area (denoted as imaging area CA) by the image sensor 31 is compared with the object detection area (denoted as radar area RA) by the radar sensor 32 in the vehicle traveling direction (Y-axis). Direction). Therefore, when the object exists in a position overlapping the imaging area CA and the radar area RA in front of the host vehicle CS, it can be detected as the fusion target FT. On the other hand, when the object is located far or near in the Y-axis direction from the imaging area CA, image loss occurs. Hereinafter, an area in front of the imaging area CA in the vehicle traveling direction is also referred to as a neighborhood area NA.

As shown in FIG. 4B, when the object is located in the neighborhood area NA, the image sensor 31 cannot specify the type of the image target IT because the lower end side of the rear end portion of the object deviates from the angle of view θ1 of the image sensor 31. Image lost occurs. Here, the vicinity area NA is a position close to the front of the host vehicle CS, and if the operating conditions are changed so that the PCS becomes difficult to operate when image information is lost in the vicinity area NA, the PCS It becomes a factor of operation delay and malfunction. Therefore, the control unit 22 maintains the operating conditions of the PCS for the object when the image is lost due to the object entering the vicinity area NA.

The position determination unit 23 determines whether or not the object is located in the vicinity area NA when the state is changed from the state in which the fusion information is generated for the object to the state in which the object is detected only with the radar information. judge. As shown in FIG. 4B, the neighborhood area NA is preset with areas in the Y-axis direction and the X-axis direction based on the angle of view θ <b> 1 spreading in the vertical direction of the image sensor 31. For example, the range of the vicinity area NA is set based on the relationship between the angle of view θ1 in the vertical direction of the image sensor 31 and the position in the height direction of the host vehicle CS to which the image sensor 31 is attached.

When the position determination unit 23 determines that the object is located in the vicinity area NA, the maintenance unit 24 maintains the PCS operating condition from the state in which the fusion target FT is detected. In this embodiment, the maintenance unit 24 maintains the PCS operating condition by not causing the control unit 22 to reduce the object width WO in the horizontal direction (X-axis direction).

Next, the PCS executed by the ECU 20 will be described with reference to the flowchart of FIG. The process shown in FIG. 5 is a process performed by the ECU 20 at a predetermined cycle.

In step S11, image information is acquired based on the output from the image sensor 31. In step S12, radar information is acquired based on the output from the radar sensor 32.

In step S13, it is determined whether or not the fusion target FT has been detected. If the object is detected based on the image information and the radar information and it is determined that the image target IT and the radar target RT are the same object, the process proceeds to step S14. For example, if the difference between the position of the image target IT based on the image information acquired in step S11 and the position of the radar target RT based on the radar information acquired in step S12 is equal to or less than a predetermined distance, the image It is determined that the target IT and the radar target RT are the same object (fusion target FT). On the other hand, when image information or radar information is not acquired, or when the difference between the position of the image target IT and the position of the radar target RT exceeds a predetermined distance, the image target IT and the radar target It is determined that the object is different from RT.

In step S14, the image information acquired in step S11 and the radar information acquired in step S12 are combined to generate fusion information that is position information for the fusion target FT. The fusion information includes the object width WO in addition to the position of the object.

In step S15, the number of detections DN, which is the number of times the fusion target FT has been detected, is recorded. The number of detections DN is information indicating the number of times that the same type of fusion target FT is continuously detected. In this embodiment, every time the same type of fusion target FT is detected in step S13, the detection count DN is increased.

In step S21, a collision with an object is determined. First, description will be made assuming that the fusion target FT is detected in step S13. The collision determination between the object and the host vehicle CS is performed using the lap ratio RR between the object width WO and the determination area Wcd included in the fusion information calculated in step S14.

In step S22, it is determined whether or not to perform PCS. If it is determined in step S21 that there is a possibility of collision with the object, the TTC is calculated by dividing the relative distance Dr in the object by the relative speed Vr, and the calculated TTC is set to the TTC set for each controlled object 40. By comparing, it is determined whether or not each operation is performed. When performing PCS (step S22: YES), in step S23, the corresponding operation of PCS is performed. On the other hand, when the corresponding operation of PCS is not performed (step S22: NO), the process shown in FIG. Steps S21 to S23 function as a control process.

On the other hand, if the fusion target FT has not been detected in step S13, it is determined in step S16 whether or not fusion target detection has been established for the same object in the past. For example, by referring to the detection number DN, it is determined whether or not the fusion target FT has been detected in the past processing. If the fusion target FT has not been detected in the past process (step S16: NO), the process shown in FIG. 5 is temporarily terminated.

When the fusion target FT is detected for the same object (step S16: YES), in step S17, it is determined whether or not the radar target RT is continuously detected. This is because the object is present in the radar area RA if the position of the object can be detected by the radar sensor 32 even when image loss occurs. If the radar target RT has not been detected (step S17: NO), the processing of FIG. 5 is once terminated, assuming that no object exists in front of the host vehicle. Therefore, the object is excluded from the PCS target. On the other hand, when the radar target RT is detected (step S17: YES), it is determined that image loss has occurred, and the process proceeds to step S18.

In step S18, it is determined whether or not the radar target RT is located in the vicinity area NA. In this embodiment, the vicinity area NA is set as an area partitioned by the vehicle traveling direction (Y-axis direction) and the lateral direction (X-axis direction). Based on the radar information acquired in step S12, it is determined whether or not the position of the radar target RT is located in an area determined as the neighborhood area NA. Step S18 functions as a position determination step.

As shown in FIG. 6, a predetermined distance from the center of the host vehicle CS in the lateral direction is defined as a boundary line BD in the lateral direction of the neighborhood area NA. Note that the range of the vicinity area NA in the vehicle traveling direction is determined based on the angle of view of the image sensor 31. If the position of the radar target RT in the lateral direction of the position Pr is on the inner side of the lateral area of the neighboring area NA defined by the boundary line BD, the object is located in the neighboring area NA. judge. On the other hand, when the position Pr is outside the determined neighboring area NA in the horizontal direction, it is determined that the object is not located in the neighboring area NA. In this embodiment, the boundary line BD is used as a fixed value determined in advance based on the imaging area CA of the image sensor 31. In addition to this, the boundary line BD may be changed in the horizontal direction according to the type of the object.

When the radar target RT is not located in the vicinity area NA (step S18: NO), in step S20, the operating condition of the PCS is changed by reducing the object width WO. In this case, since there is a high possibility that the object Ob is located far from the imaging area CA in the vehicle traveling direction, the possibility that the object Ob and the host vehicle CS collide with each other is low. Therefore, priority is given to the low reliability of the object width WO acquired in the past, and the object width WO is reduced in the horizontal direction. That is, in this embodiment, the wrap rate RR associated with the object width WO is set as the PCS operating condition. In step S21, collision determination is performed using the reduced object width WO. As a result, the lap rate RR decreases and the PCS becomes difficult to operate.

On the other hand, when the radar target RT is located in the vicinity area NA (step S18: YES), the PCS operating condition is changed in step S19. In step S19, it is switched whether to change or maintain the PCS operating condition by determining the possibility of collision between the object Ob and the host vehicle CS according to various conditions.

Next, detailed processing performed in step S19 in FIG. 5 will be described with reference to FIG. In the process shown in FIG. 7, when all the conditions up to Steps S31 and S32 are satisfied, it is determined that there is a high possibility that the object Ob and the host vehicle CS will collide, and the object width WO is maintained. Therefore, step S19 functions as a maintenance process.

First, in step S31, the relative speed Vr of the radar target RT with reference to the host vehicle CS is determined. Since the TTC is calculated by dividing the relative distance Dr by the relative speed Vr, the TTC until the radar target RT and the host vehicle CS collide increases as the relative speed Vr decreases for the same relative distance Dr. It becomes. Therefore, when the relative speed Vr is small, it is more likely that each operation of the PCS is not performed even after the radar target RT has entered the vicinity area NA, as compared with a case where the relative speed Vr is large.

Therefore, when the relative speed Vr is larger than the threshold value Th1 (step S31: NO), the process proceeds to step S33, and the object width WO is reduced. The reduction of the object width WO performed in step S33 can use the same technique as the reduction of the object width WO performed in step S20. On the other hand, if the relative speed Vr is equal to or less than the threshold value Th1 (step S31: YES), the process proceeds to step S32. Step S31 functions as a relative speed acquisition unit.

In step S32, the number DN of detections of the fusion target FT before the image lost occurs is determined. The number of detections DN indicates the number of times the radar target RT has been detected in the past as the fusion target FT. Therefore, if the number of detections DN is small, the reliability of the fusion target FT decreases. For example, when the detection of the fusion target FT is accidental due to noise or the like, the detection count DN is a low value. Therefore, if the number of detections DN is smaller than the threshold value Th2, the process proceeds to step S33, and the object width WO is reduced.

On the other hand, if the number of times of detection DN is greater than or equal to the threshold Th2 (step S32: YES), the processing shown in FIG. That is, the object width WO is maintained. Therefore, in step S21 in FIG. 5, the collision determination is performed based on the maintained object width WO, so that the PCS is easily activated.

Next, changes in the operability of the PCS when the ECU 20 performs the process of FIG. 5 will be described with reference to FIGS. 8A and 8B. 8A and 8B show changes in the object width WO when the ECU 20 performs the process of FIG. 5, and FIG. 8C shows changes in the object width WO when the ECU 20 does not execute the process of FIG. Is shown.

As shown in FIG. 8A, at time t11, when the fusion target FT is detected in front of the host vehicle CS by the ECU 20, the relative distance Dr of the fusion target FT with respect to the host vehicle CS becomes smaller. To do. Then, as shown in FIG. 8B, it is assumed that an image has been lost due to the object entering the vicinity area NA at time t12.

When the image lost occurs, the position of the object (radar target RT) is detected only with the radar information, and the object width WO cannot be acquired. Here, in FIG. 8B, since the radar target RT is located in the vicinity area NA at time t12, the object width WO (t12) at time t12 is maintained at the same size as the object width WO at time t11. The On the other hand, in FIG. 8C shown as a comparison, when the object is located in the vicinity area NA, the object width WO (t12) at time t12 is reduced more than the object width WO (t11) at time t11 shown in FIG. 8A. Yes.

Therefore, in FIG. 8B, by maintaining the object width WO (t12), the wrap rate RR indicating the ratio to the determination region Wcd is larger than the wrap rate RR (c) in the case of FIG. . As a result, the PCS becomes easy to operate, and the PCS operation delay or inactivity with respect to the radar target RT is suppressed.

As described above, in the first embodiment, the ECU 20 detects the radar target RT when the image lost occurs from the state in which the fusion target FT is detected and the object is detected only with the radar information. If the position is located in the vicinity area NA in front of the vehicle, the PCS operating condition is maintained. With the above configuration, even when an image is lost due to the object entering the vicinity area NA, it is possible to suppress the delay or inactivation of the PCS with respect to the object.

The ECU 20 acquires the object width WO indicating the size of the object in the horizontal direction, and based on the amount of overlap (RR) in the horizontal direction between the acquired object width WO and the determination region Wcd set in front of the vehicle. Change the operating conditions of the PCS. Then, when the object is located in the vicinity area NA, the ECU 20 maintains the object width in a state where the object is detected by the image information and the radar information. With the above configuration, it is possible to change the operating conditions of the PCS by a simpler method.

Even if the object is positioned near the host vehicle CS in the vehicle traveling direction, if the object is positioned far from the host vehicle CS in the lateral direction, the possibility of a collision between the object and the host vehicle CS is reduced. Therefore, the ECU 20 determines that the object is not located in the vicinity area NA if the position Pr of the object acquired from the radar information is outside the preset vicinity area NA. With the above configuration, when the possibility of a collision between the object and the host vehicle CS is low, priority is given to the fact that the detection accuracy is lowered, so that appropriate PCS can be performed.

If the relative speed Vr of the object is small, TTC, which is a margin time until the object collides with the host vehicle CS, increases, and even if the object is located in the vicinity area NA, compared to an object having a large relative speed Vr. There is a high possibility that PCS is not implemented. Therefore, the ECU 20 maintains the PCS operating condition when the object is located in the vicinity area NA on condition that the relative speed Vr of the object is equal to or less than a predetermined value. With the above configuration, when the object Ob is located in the vicinity area NA, the PCS can be actively activated to suppress the inactivation.

(Second Embodiment)
In the second embodiment, when the object is located in the vicinity area NA, if the object moves in a direction away from the host vehicle CS, the ECU 20 makes it difficult to operate the PCS.

FIG. 9 is a flowchart showing the process performed in step S19 of FIG. 5 in the second embodiment.

In step S41, it is determined whether or not the host vehicle CS is traveling straight ahead. For example, based on the output from the turning motion detection sensor 34, it is determined whether the host vehicle CS is traveling straight or turning right or left. If the host vehicle CS is not traveling straight ahead (step S41: NO), the object width WO is reduced in step S43.

If the host vehicle CS is traveling straight (step S41: YES), in step S42, it is determined whether or not the radar target RT located in the vicinity area NA is traveling straight. FIG. 10 is a diagram for explaining the movement of an object in the vicinity area NA. As illustrated in FIG. 10A, if an object detected in front of the host vehicle CS is traveling straight in the vehicle traveling direction (Y-axis direction), the possibility that the object and the host vehicle CS collide with each other increases. In such a case, it is preferable to maintain the object width WO.

On the other hand, as shown in FIG. 10B, when the object turns left and right in the vicinity area NA and moves in the lateral direction (X-axis direction) with respect to the vehicle traveling direction (Y-axis direction), the object Since moving away from the course, the possibility that the object and the host vehicle CS collide with each other is reduced. In such a case, if the object width WO is maintained, there is a risk of erroneously determining that there is a possibility of collision even with an object that is actually unlikely to collide, which causes unnecessary operation of the PCS.

Therefore, in step S42, the radar information is used to detect a change in the position of the radar target RT, and based on this change in position, it is determined whether the radar target RT is going straight or turning right or left. In addition to this, when it is detected using the radar information that the lateral position has changed after the vehicle speed of the radar target RT has decreased, it may be determined that the radar target RT has turned right or left. Therefore, step S42 functions as a movement determination unit.

If the radar target RT is traveling straight (step S42: YES), the processing of FIG. 9 is temporarily terminated without reducing the object width WO. Therefore, the operating conditions of the PCS are maintained. On the other hand, if the radar target RT is not traveling straight and the object is turning left or right (step S42: NO), in step S43, the operating condition is changed by reducing the object width WO. Therefore, in step S20 of FIG. 5, the collision determination with the object is performed using the maintained or reduced object width WO.

As described above, when an object located in the vicinity area NA turns right and left so that the object moves in a direction away from the host vehicle CS, the object and the host vehicle CS are both traveling straight ahead. In comparison, the possibility of a collision is reduced. In such a case, the ECU 20 makes it difficult to operate the PCS. With the above configuration, when the possibility of collision between the object and the host vehicle CS is low, priority is given to the fact that the detection accuracy is lowered, and therefore appropriate PCS can be performed.

(Third embodiment)
In the third embodiment, the area set as the neighborhood area NA is different from that in the first and second embodiments.

FIG. 11 is a diagram illustrating the position of the neighborhood area NA in the third embodiment. In the third embodiment, the radar area RA of the radar sensor 32 is set to be wider than the imaging area CA of the image sensor 31. The neighboring area NA is an area (VA to BA) that extends from the angle of view VA of the image sensor 31 by the boundary angle BA in the horizontal direction. In addition, the neighborhood area NA is an area where the first position can be detected from the object but the second position cannot be detected. Therefore, in the present embodiment, the neighborhood area NA is outside the imaging area CA of the image sensor 31. In addition, it is set as an area inside the radar area RA of the radar sensor 32.

FIG. 12 is a flowchart showing the process performed in step S14 of FIG. 5 in the third embodiment. The process shown in FIG. 12 is a process for recording the center position in the lateral direction of the object, the object width WO, and the relative velocity in the lateral direction when detecting radar information and image information from the object. In the following, the process of FIG. 12 performed last time by the ECU 20 is described as the previous process, and the process of FIG. 12 performed this time is described as the current process.

In step S51, the distance of the object detected as radar information and the orientation of the object detected as image information are fused.

In step S52, the center position of the object in the lateral direction is calculated based on the image information acquired in step S11 of FIG. In the present embodiment, as shown in FIG. 13, the center positions of the left and right lateral positions Xr and Xl included in the image information are calculated as the center position in the lateral direction of the object. Step S52 functions as a center position calculation unit.

In step S53, the object width WO is calculated. In the present embodiment, the object width WO is calculated using the left and right lateral positions Xr, Xl of the object included in the image information. In the present embodiment, the object width WO is calculated using the following formula (1).
WO = | Xr−Xl | (1).

When the image sensor 31 outputs an image width angle indicating a difference in azimuth angle between the left and right lateral positions of the object, the object width WO may be calculated as follows. In this case, in step S53, the object width may be calculated using the image width angle and the distance from the host vehicle to the object.

In step S54, the maximum value of the object width WO is updated. For example, the object width WO held in the previous process is compared with the object width WO recorded in the previous process, and the larger object width WO is updated as the object width WO. Therefore, steps S53 and S54 function as an object width calculation unit.

In step S55, a relative speed based on the own vehicle in the lateral direction of the object is calculated. For example, the relative speed in the lateral direction is calculated from the difference in the lateral position between the position of the fusion information generated in step S51 in the previous process and the position of the fusion information generated in step S51 in the current process. . Therefore, step S54 functions as a lateral speed calculation unit. When the process of step S55 ends, the process returns to the flowchart shown in FIG.

Next, processing for determining whether or not a part of an object is located in the vicinity region will be described with reference to FIGS. The process shown in FIG. 14 is a process performed in step S18 of FIG.

In step S61, the predicted center position in the lateral direction of the object at the current time is calculated based on the center position calculated in the past from the current time and the lateral speed of the object. In the present embodiment, the predicted center position of the object width of the object at the current time is calculated based on the image information calculated in step S52 and the lateral velocity of the object calculated in step S55. As shown in FIG. 15, a distance corresponding to the relative velocity in the lateral direction of the object recorded in step S54 is added to the center position M of the object width calculated from the image information held in step S52. Thus, the predicted center position Mp of the current center position of the object is calculated. Step S61 functions as a position prediction unit.

In step S61, in addition to calculating the predicted center position Mp based on the center position recorded in the past and the lateral speed of the object according to the image information, the center position recorded in the past and the radar information The predicted center position Mp may be calculated based on the lateral speed of the object according to the above.

In step S62, the left and right end angles of the left and right lateral positions of the object at the current time are calculated based on the predicted center position calculated in step S61 and the object width WO held in step S53. Here, the left and right end angles indicate the azimuth angles of the left and right lateral positions of the current object with reference to the host vehicle.

In the present embodiment, as shown in FIG. 16, first, a position extending in the horizontal direction by the object width WO updated in step S54 on the basis of the predicted center position Mp calculated in step S61 is set to the left and right sides of the object. The predicted horizontal positions Xpr and Xpl of the horizontal position are calculated. Next, using the calculated predicted lateral positions Xpr and Xpl, left and right end angles indicating the azimuth angles of the left and right lateral positions of the current object are calculated. In the present embodiment, the left and right end angles are positive when the angle increases to the right with reference to the imaging axis, and negative when the angle increases to the left with respect to the imaging axis.

When the left and right end angles on the side close to the host vehicle in the lateral direction are θn and the left and right end angles on the side far from the host vehicle are θf, the relationship between the left and right end angles and the predicted lateral position 3).
tan θn = X1 / Yd (2)
tan θf = X2 / Yd (3)
Here, X1 indicates the predicted lateral position on the side closer to the own vehicle among the predicted lateral positions Xpr and Xpl, and X2 indicates the predicted lateral position on the side farther from the own vehicle among the predicted lateral positions Xpr and Xpl. . In FIG. 16, Xpl is the predicted lateral position X1 on the side closer to the host vehicle, and Xpr is the predicted lateral position X2 on the side farther from the host vehicle. Yd represents the distance from the host vehicle to the object. In this embodiment, the distance from the host vehicle to the object included in the fusion information is used.

From the above equations (2) and (3), the ECU 20 can calculate the left and right end angles using the following equations (4) and (5), respectively.
θn = arctan (X1 / Yd) (4)
θf = arctan (X2 / Yd) (5)
Therefore, step S62 functions as an azimuth angle calculation unit.

In steps S63 to S66, it is determined based on the left and right end angles calculated in step S62 that the object is located in the vicinity region. In the present embodiment, based on the left and right end angle θf far from the host vehicle among the left and right end angles calculated in step S62, the parting reliability indicating the certainty that a part of the object is located in the vicinity region. Calculate the degree. Therefore, in the present embodiment, steps S63 to S66 function as a position determination unit.

FIG. 17 is a diagram for explaining the part-off reliability, and is a graph in which the horizontal axis is the absolute value of the left and right end angle θf and the vertical axis is the part-off reliability RV. The part-off reliability RV is an evaluation value for determining whether or not the vehicle is located in the vicinity region based on the left and right end angles on the side far from the host vehicle in the horizontal direction. In this embodiment, the parting reliability is defined by a value from 0 to 100, and the probability that a part of the object is located in the vicinity region increases as the parting reliability increases. Further, the value of the part-off reliability is defined such that the value increases nonlinearly as the value of the left and right end angle θf on the side far from the host vehicle increases.

Of the left and right end angles θf on the horizontal axis, the reference angle B indicates the absolute value of the angle from the imaging axis to the angle of view. In other words, when the left and right end angle θf is the reference angle B, the end on the side farther from the host vehicle is located on the angle of view of the image sensor 51 among the left and right lateral positions of the object.

The part-off reliability RV has a value such that the increase rate in the center range MR, which is a range of the predetermined angles R1 to R2, with respect to the reference angle B, is larger than the increase rates at the lower limit angle R1 or lower and the upper limit angle R2 or higher. Is set. By increasing the increase rate in the center range MR more than other regions, when the left and right end angles are smaller than the lower limit angle R1 or larger than the upper limit angle R2, it is possible to suppress a large change in the part-off reliability RV. The As a result, as the left / right end angle θf is closer to the angle of view, the change in the part-off reliability increases, and the influence of the error in mounting the image sensor 31 in the lateral direction with respect to the host vehicle or the error in the left / right end angle calculated in step S62. Can be reduced.

In step S63, the part-off reliability is calculated based on the left and right end angles. Of the left and right end angles, the part-off reliability is calculated for the left and right end angles far from the host vehicle. For example, a map defining the relationship between the left and right end angles and the parting reliability shown in FIG. 17 is recorded, and the parting reliability corresponding to the left and right end angles calculated in step S62 is calculated by referring to this map. To do.

In step S64, the part-off reliability calculated in step S63 is determined. In the present embodiment, it is determined whether or not a part of the object is located in the vicinity region by comparing the overrun reliability with the threshold Th11. The threshold value Th11 is determined based on a reference angle B indicating the absolute value of the angle from the imaging axis to the angle of view.

If the overrun reliability is equal to or greater than the threshold Th11 (step S64: YES), in step S65, the establishment flag indicating that a part of the object is located in the vicinity region is set to true. On the other hand, when the part-off reliability is less than the threshold value Th11 (step S64: NO), in step S66, the establishment flag indicating that the object is located in the vicinity region is set to false. When the establishment flag is false, it is determined that the object is not located in the vicinity region.

Referring back to FIG. 5, if the establishment flag is true, it is determined that the object is located in the vicinity region (step S18: YES), and the operating conditions of the PCS are maintained in step S19. For example, the object width WO is maintained at the object width WO when the fusion is established. On the other hand, if the establishment flag is false, it is determined that the object is not located in the vicinity region (step S18: NO), and the PCS operating condition is changed in step S20. For example, the object width WO is reduced more than the object width WO when the fusion is established.

As described above, in the third embodiment, the ECU 20 is detected in the past when the object changes from the state detected by the radar information and the image information to the state detected only by the radar information. The predicted center position of the object at the current time is calculated based on the center position in the lateral direction of the object and the lateral speed of the object. Further, based on the calculated predicted center position and the object width, the left and right end angles indicating the azimuth angles of the left and right lateral positions of the current object with respect to the host vehicle are calculated. Then, the ECU 20 determines whether or not the object is located in the vicinity region based on the calculated left and right end angles. In this case, even if the neighboring region is a region that extends outward by a predetermined angle in the horizontal direction from the angle of view of the image sensor 31, it can be properly determined whether or not the object is located in this neighboring region.

Based on the calculated left and right end angles, the ECU 20 calculates a parting reliability indicating the certainty that the object is located in the vicinity region, and when the calculated parting reliability is equal to or greater than a threshold, It is determined that it is located in the vicinity region. The missing reliability is set to increase nonlinearly as the left and right end angles of the object on the far side from the host vehicle increase, and the value of the center range in the range within the predetermined angle with respect to the angle of view is set. The rate of increase in the part-off reliability is higher than in other areas. In this case, by setting the increase rate in the center range to be larger than that in the other regions, when the left and right end angles are higher than the lower limit value of the center range, the parting reliability is likely to increase. As a result, in determining whether or not the vehicle is located in the vicinity region, it is possible to reduce the influence of the horizontal mounting error of the image sensor 31 with respect to the host vehicle and the calculation error of the left and right end angles.

(Other embodiments)
In the third embodiment described above, as a method of determining whether or not the object is turning right or left, the subsequent object motion is predicted using the object characteristics when the fusion target FT is established. It may be a thing. For example, in step S14 of FIG. 5, the ECU 20 detects blinking of a direction indicator lamp such as a blinker from the image information as the fusion information as a feature indicating a right or left turn, and the fusion target FT is not detected in the next processing. (Step S13: NO), the past object width WO may be reduced. Further, in step S14 of FIG. 5, when the fusion target is detected based on the captured image that the object straddles the intersection white line at the intersection, and the fusion target FT is not detected in the next processing (step S13: NO), The past object width WO may be reduced.

The position of the object in the horizontal direction at the time when the fusion target FT is established is recorded, and when image loss occurs, the PCS operating condition is determined based on the recorded past position of the object. It may be changed. In this case, for example, in step S14 of FIG. 5, the ECU 20 acquires the lateral position of the object from the image information as the fusion information, and does not detect the fusion target FT in the next process (step S13: NO), step Based on the lateral position acquired in S14, it is determined whether or not the object is located in the neighborhood area NA. Specifically, if the recorded lateral position of the object is inside the lateral range of the neighboring area NA, it is determined that the current object is located in the neighboring area NA.

Instead of maintaining the PCS operation condition uniformly when the object is located in the vicinity area NA, the PCS operation condition may be changed based on the position of the object in the vicinity area NA. In this case, in step S19 of FIG. 5, when the object is located in the vicinity area NA, the ECU 20 maintains the PCS operating condition if the relative distance Dr between the host vehicle CS and the object is equal to or greater than a threshold value. If the relative speed Vr is the same, the TTC increases as the relative distance Dr increases. Therefore, when the relative distance Dr after the radar target RT has entered the vicinity area NA is large, there is a high possibility that the PCS is not performed compared to the case where the relative distance Dr is small. Therefore, when the relative distance Dr is greater than or equal to a predetermined value in step S19, the ECU 20 makes the PCS easier to operate by maintaining the object width WO.

The PCSS 100 may include the ECU 20 and the image sensor 31 as an integrated device instead of the configuration including the ECU 20 and the image sensor 31 individually. In this case, the ECU 20 described above is provided inside the image sensor 31. The PCSS 100 may include a laser sensor that uses laser light as a transmission wave instead of the radar sensor 32.

When the vehicle speed of the host vehicle CS is equal to or higher than a predetermined value when the object is located in the vicinity area NA, the PCS operating condition may be maintained.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

The first information that is the detection result of the object based on the reflected wave corresponding to the transmission wave, and the second information that is the detection result of the object based on the captured image obtained by imaging the front of the vehicle with the imaging unit. A vehicle control device for detecting,
A control unit (22) for performing collision avoidance control for avoiding a collision with the object based on at least one of the first information and the second information;
When the object transitions from the state detected by the first information and the second information to the state detected only by the first information, the object cannot acquire the second information in front of the vehicle A position determination unit (23) for determining whether or not it is located in a nearby region that is predetermined as a region;
A maintenance unit that maintains an operation condition of the collision avoidance control from a state in which the object is detected by the first information and the second information when it is determined that the object is located in the vicinity region ( 24).
The control unit acquires an object width indicating a size of the object in the lateral direction, and based on the amount of overlap in the lateral direction between the acquired object width and a determination region set in front of the vehicle Change the operation condition of collision avoidance control,
2. The maintenance unit according to claim 1, wherein, when the object is located in the vicinity region, the object width is maintained to a size in a state in which the object is detected by the first information and the second information. The vehicle control device described.
The position determination unit determines a predetermined distance from the center of the vehicle in the lateral direction of the vehicle as a range in the lateral direction of the neighboring region, and the position of the object acquired based on the first information 3. The vehicle control device according to claim 1, wherein the vehicle control device determines that the object is located in the vicinity area when a position in a lateral direction is inside a range of the vicinity area. .
A movement determination unit that determines whether the object is moving in a direction away from the vehicle in a lateral direction of the vehicle;
The maintenance unit is a case where the position determination unit determines that the object is located in the vicinity region, and the object is moving in a direction away from the vehicle in the lateral direction. The vehicle control device according to any one of claims 1 to 3, wherein the operation condition is changed so that the collision avoidance control is difficult to operate.
A relative speed acquisition unit that acquires a relative speed of the object with respect to the vehicle;
The said maintenance part maintains the said operation condition, when it determines with the said object being located in the said vicinity area on the condition that the said relative speed is below a predetermined value. The vehicle control device according to claim 4.
The maintenance unit transitions from a state in which the object is detected by the first information and the second information to a state in which the object is detected only by the first information, and the position is determined by the position determination unit. The vehicle control device according to any one of claims 1 to 5, wherein the operation condition is changed to make it difficult to operate the collision avoidance control when it is determined that the vehicle is not located in an area.
The vicinity region is a region that extends a predetermined angle in the horizontal direction from the angle of view of the imaging means,
A center position calculation unit that calculates a center position of the object in the lateral direction based on the second information in a state where the object is detected by the first information and the second information;
An object width calculating unit that calculates an object width indicating a size of the object in a lateral direction based on the second information in a state where the object is detected by the first information and the second information;
A lateral speed calculator that calculates a lateral speed of the object based on at least one of the first information and the second information;
The center position calculated in the past from the present time when the object is changed from the state detected by the first information and the second information to the state detected only by the first information; and A position prediction unit that calculates a predicted center position in the lateral direction of the object at a current time based on a lateral speed of the object;
An azimuth angle calculation unit that calculates azimuth angles of the lateral positions of the current object on the basis of the host vehicle based on the calculated predicted center position and the object width;
The vehicle control device according to claim 1, wherein the determination unit determines whether or not the object is located in the vicinity region based on the calculated azimuth angle of the left and right lateral positions. .
The determination unit calculates a part-off reliability indicating the certainty that the object is located in the vicinity region based on the azimuth angles of the left and right lateral positions, and the calculated part-off reliability is equal to or greater than a threshold value. Is determined to determine that the object is located in the vicinity region,
The part-off reliability is
The value is set to increase nonlinearly as the azimuth angle of the object on the side far from the vehicle increases.
The vehicle control device according to claim 7, wherein a value is set such that an increase rate in a range of a predetermined angle with respect to the angle of view is higher than an increase rate in another range.
The first information that is the detection result of the object based on the reflected wave corresponding to the transmission wave, and the second information that is the detection result of the object based on the captured image obtained by imaging the front of the vehicle with the imaging unit. A vehicle control method for detecting,
A control step of performing collision avoidance control for avoiding a collision with the object based on at least one of the first information and the second information;
When the object transitions from the state detected by the first information and the second information to the state detected only by the first information, the object cannot acquire the second information in front of the vehicle A position determination step for determining whether or not it is located in a nearby region that is predetermined as a region;
Maintaining the operation condition of the collision avoidance control from a state in which the object is detected by the first information and the second information when it is determined that the object is located in the vicinity region; A vehicle control method.