VEHICLE CONTROL DEVICE AND VEHICLE CONTROL METHOD

Abstract

Vehicle control device (10) used for a vehicle in which a target detection device (21) detecting a target in the vicinity of its own vehicle (50) is arranged, and which performs vehicle control based on a detection result of the target detection device, wherein the vehicle control device comprises: a means of obtaining angular misalignment information from the target detection device, calculated on the basis of a detection position of the target by means of the target detection device, with a predetermined cycle;a calculation device for calculating an axle misalignment angle, which is a misalignment parameter of an attachment angle of the target acquisition device, and an axle misalignment direction, which indicates a left or right side in relation to the own vehicle on which the axle misalignment of the target acquisition device has occurred, by statistically processing a history after initiating the acquisition of the angle misalignment information by means of the acquisition device; a detection range setting device for setting a detection range in front of the own vehicle in which a target to be subjected to driving control of the own vehicle is detected from targets detected by the target acquisition device;and a detection range limitation device for reducing a width in a transverse direction of the detection range based on a predetermined initial angle, which is the misalignment magnitude of the mounting angle of the target detection device, until a predetermined initial time period after start-up has elapsed, and for reducing the width in the transverse direction of the detection range based on the axis misalignment angle and axis misalignment direction calculated by the calculation device, after the initial time period after start-up has elapsed.

Description

[Technical Field]The present invention relates to a vehicle control device that performs traveling control of an own vehicle with respect to a target ahead of the own vehicle detected by a target detection device, and a vehicle control method performed by the vehicle control device.[Prior Art]Pre-crash safety (PCS) systems that reduce or prevent damage from a collision between an obstacle (target) and an own vehicle are known. The obstacle is another vehicle, a pedestrian, a road structure, or the like that is present in front of the own vehicle and has been detected by a target detection device such as an imaging device or a radar device. In the PCS, a collision prediction time (time to collision [TTC]) is determined based on a relative distance between the own vehicle and the obstacle and a relative speed or acceleration. The collision prediction time is a time until a collision would occur between the own vehicle and the obstacle. Based on the collision prediction time, an approach is notified to a driver of the own vehicle by a warning device, or a brake device of the own vehicle is operated.However, when an axis misalignment in which an attachment angle of the target detection device is inclined occurs, an obstacle that is not actually located in front of the own vehicle is erroneously detected as being located in front of the own vehicle. The axle misalignment of the target detection device may occur as a result of vibrations occurring during vehicle travel, a slight impact on the own vehicle, and the like.Therefore, axis misalignment detection has been performed for the target detection device since the past. For example, when a radar device is used as the target detection device, angular misalignment information of the radar device is acquired from a movement trajectory of a road-side object detected by the radar device. Then, as a result of statistical processing of a history of the angle misalignment information, an axis misalignment angle of the radar device is calculated (see JP 10-132 939 A).JP 2008-203 147 A discloses a vehicular radar having an axis regulating function with which the direction axis of the radio wave emission can be regulated. A radio wave is transmitted from the radar while the angle of an antenna of the radar is changed by a motor. The reception intensities of the radio waves received from the radar are sequentially stored in a storage device according to the distances. A sum of the average radio wave intensities is calculated for each distance, the calculated sum of the average radio wave intensities is compared with a sum of the radio wave intensities at a distance with respect to another current vehicle, and the angle of the antenna of the radar is set by the motor to be set to the previous angle when the previous sum of the average radio wave intensities is larger and set to the current angle when it is smaller. In calculating the sum of the average radio wave intensities, a greater weight is given as the distance to the other vehicle increases.JP H10-39 014 A discloses on-board radar equipment in which the number of the direction data of a preceding vehicle averaged to correct the central axis direction of the beams is changed in response to the running conditions.U.S. Pat. No. 6,122,040 A discloses a method for detecting and correcting an axis deviation of a distance measuring device, in which a plurality of detection data parts of a preceding vehicle, which have been collected in a straight traveling state in which an own vehicle and a preceding vehicle travel straight on the same straight line, are extracted as effective detection data. The setting of an internal parameter is automatically changed so that a center point of the detection range coincides with an average center point of the preceding vehicle obtained by statistical processing of the pieces of detection data.DE 60 2005 000 618 T2 discloses a method for automatically determining an axial misalignment of an automobile radar, wherein the amount of the axial deviation of the radar is determined on the basis of a calculated line of stationary objects on the basis of the distribution of the stationary objects. In the case where a factor for determining the calculated line of the stationary object that reduces the calculation accuracy of the axial deviation is found in the distribution of stationary objects, the calculation of the amount of the determined axial deviation is discontinued.[Summary of the Invention]When the axis misalignment angle is calculated by statistical processing, it takes time for the determination accuracy in the axis misalignment to improve. Therefore, the axis misalignment angle cannot be calculated in a state where the calculation accuracy with respect to the axis misalignment angle is low. An unexpected unnecessary assist operation may be performed with respect to an obstacle erroneously determined to be in front of the own vehicle.It is a primary object of the present invention to provide a vehicle control device capable of preventing unnecessary assist operations with respect to a target and a vehicle control method.A first aspect of the present invention relates to a vehicle control apparatus (10) used for a vehicle in which a target detector (21) that detects a target in a vicinity of an own vehicle (50) is disposed, and performs travel control of the vehicle on the basis of a detection result of the target detector. The vehicle control apparatus includes: acquisition means for acquiring angle misalignment information of the target detection means calculated based on a detection position of the target by the target detection means at a predetermined cycle; calculation means for calculating an axis misalignment angle, which is a misalignment amount of an attachment angle of the target detection means, and an axis misalignment direction indicating a left or right side with respect to the own vehicle on which the axis misalignment of the target detection means has occurred by statistically processing a history after starting acquisition of the angle misalignment information by the acquisition means; a detection range setting means for setting a detection range in front of the own vehicle in which a target to be subject to travel control of the own vehicle is detected from targets detected by the target detection means; and detection range restricting means for reducing a width in a lateral direction of the detection range based on a predetermined initial angle, the initial angle being the misalignment amount of the attachment angle of the target detection means until a predetermined initial time period has elapsed after starting, and for reducing the width in the lateral direction of the detection range based on the axle misalignment angle and the axle misalignment direction calculated by the calculating means after the elapse of the initial time period after starting.According to the first aspect of the present invention, during the initial period, the width in the lateral direction of the detection range in which the target to be subjected to the travel control of the own vehicle is detected is decreased using the predetermined initial angle. In this case, even if any axis misalignment to the right or left occurs in the target detecting means during the initial period during which the accuracy of the axis target orientation angle is low, a target that does not exist in front of the own vehicle is erroneously determined as a target to be subjected to the travel control is prevented.In addition, in a state in which the initial period has elapsed and the detection of the axis misalignment angle and the axis misalignment direction of the target detection means becomes possible, the width in the lateral direction of the detection region is decreased based on the axis misalignment angle and the axis misalignment direction. Therefore, based on the occurrence state of the axle misalignment in the target detecting means, it can be prevented that a target that is not present in front of the own vehicle is erroneously determined as a target to be subjected to the travel control.[Brief Description of Drawings]The above object, other objects, features and advantages of the present invention will become apparent from the following detailed description with reference to the accompanying drawings. The following are shown: FIG. 1 is a configuration diagram showing a vehicle control device according to an embodiment; FIG. 2 is a diagram showing an arrangement of an imaging device and a radar device according to an embodiment; FIG. 3 is an explanatory diagram showing the principle of axis misalignment angle detection according to an embodiment; FIG. 4 is a diagram showing a distribution of an axis misalignment amount according to an embodiment; FIG. 5 is a diagram showing a relationship between a detection time and detection accuracy with respect to axis misalignment according to an embodiment; FIG. 6 is an explanatory diagram regarding setting of a detection range for a target in front of an own vehicle according to an embodiment; FIG. 7 is a flowchart showing processing steps of a driving support ECU according to an embodiment; FIG. 8 is an explanatory diagram concerning setting of a detection range of a modified example of an embodiment; and FIG. 9 is an explanatory diagram concerning setting of a detection range of a modified example of an embodiment.[Description of Embodiments]Each embodiment will be described below with reference to the drawings. Portions that are identical or equivalent in the embodiments are denoted by the same reference numerals in the drawings. The description of the portions having the same reference numerals will be used with each other.A vehicle control device according to the present embodiment is mounted on a vehicle (own vehicle). The vehicle control device serves as a PCS system that performs a target present in front of the own vehicle and control for preventing collision with the target or reducing collision damage.In FIG. 1, an electronic driving support control unit (ECU) 10 that is the vehicle control device is a computer including a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), an input / output interface (I / O interface), and the like (not shown). The driving support ECU 10 realizes each function as a result of running on the CPU programs installed in the ROM. Therefore, the ROM corresponds to a storage medium (non-transitory computer readable medium).As sensor devices that input various kinds of detection information, a radar device 21, an imaging device 22, a vehicle speed sensor 23, a steering angle sensor 24, and a yaw rate sensor 25 are connected to the driving support ECU 10.The radar device 21 is a device that transmits electromagnetic waves as transmission waves and detects a target around an own vehicle 50 by receiving reflected waves of the electromagnetic waves. The radar device 21 is configured by, for example, a millimeter wave radar or a laser radar. As shown in FIG. 2, the radar device 21 is mounted on a front portion of the own vehicle 50 such that its optical axis X 2 faces forward of the vehicle. In addition, the radar device 21 scans a region 62 by radar signals. The region 62 extends over a region of a predetermined angle θ 2 in front of the vehicle with the optical axis X 2 as the center. The radar device 21 then generates distance measurement data based on a time period from the transmission of the electromagnetic waves in front of the vehicle to the reception of the reflected waves. The radar device 21 transmits the generated distance measurement data to the driving support ECU 10. The distance measurement data includes information regarding an orientation at which the target exists, a distance to the target, and a relative speed.The imaging device 22 is an on-board camera. The imaging device 22 is configured by a CCD (charge coupled device) camera, a CMOS (complementary metal oxide semiconductor) image sensor, a near infrared camera, or the like. The imaging device 22 captures an image of an environment including a traveling road of the own vehicle 50. The imaging device 22 generates image data expressing the captured image, and outputs the image data to the driving support ECU 10 sequentially. As shown in FIG. 2, the imaging device 22 according to the present embodiment is mounted near an upper side of a front windshield of the own vehicle 50, for example. The imaging device 22 captures an image of a region 61 that extends over a region of a predetermined angle θ 1 (θ 1>θ 2) in front of the vehicle with an imaging axis X 1 as a center. Then, the imaging device 22 extracts feature points indicating the presence of a target in the captured image. Specifically, the imaging device 22 extracts edge points on the basis of luminance information of the captured image and performs Hough transform on the extracted edge points. In the Hough transform, for example, a point on a straight line on which a plurality of edge points are continuously arranged or a point at which straight lines cross is extracted as a feature point. The imaging device 22 may be a monocular camera or a stereo camera.The vehicle speed sensor 23 is disposed in a rotation shaft that transmits power to the wheels of the own vehicle 50. The vehicle speed sensor 23 determines a speed of the own vehicle 50 based on the rotational speed of the rotary shaft. The steering angle sensor 24 detects, as the steering angle, an angle through which a steering wheel of the own vehicle 50 rotates. The yaw rate sensor 25 detects a yaw rate actually generated in the own vehicle 50, that is, an angular velocity about the center of gravity of the vehicle. The yaw rate sensor 25 includes, for example, an oscillator such as a tuning fork, and detects the yaw rate of the own vehicle 50 by detecting a slope generated in the oscillator based on a yaw moment of the own vehicle 50.The own vehicle 50 includes a warning device 41, a braking device 42, and a seat belt device 43 as safety devices that are driven based on control commands from the driving support ECU 10.The warning device 41 is a speaker or a display disposed within a cabin of the own vehicle 50. When the driving support ECU 10 determines that the possibility of collision with an obstacle has increased, the warning device 41 notifies the driver of the risk of collision by outputting a warning sound, a warning message, or the like based on the control command from the driving support ECU 10.The brake device 42 is a brake device that applies brakes to the own vehicle 50. When the driving support ECU 10 determines that the possibility of collision with an obstacle has increased, the brake device 41 is operated based on the control command from the driving support ECU 10. Specifically, the brake device 42 increases a braking force related to a braking operation by a driver (brake assist function) or performs automatic braking when the driver does not perform a braking operation (automatic brake function).The seat belt device 43 is a pretensioner that retracts a seat belt provided for each seat of the own vehicle 50. When the driving support ECU 10 determines that the possibility of collision with an obstacle has increased, the seat belt device 43 performs a preparatory operation for retracting the seat belt based on the control command from the driving support ECU 10. When the collision cannot be avoided, the seat belt device 43 retracts the seat belt and eliminates play, thereby fixing an occupant such as the driver in the seat and protecting the occupant.A target detection unit 11 acquires first detection information from the radar device 21 and second detection information from the imaging device 22, then the target detection unit 11 assigns, as to a first position, which is a position obtained from the first detection information, and a second position, which is a feature point obtained from the second detection information, the first position and the second position, which are arranged close to each other, as being based on the same target. When the second position exists in the vicinity of the first position, the possibility that a target is actually present at the first position is high. A state in which the position of a target is accurately acquired from the radar device 21 and the imaging device 22 is referred to as a fusion state. Regarding a target determined to be in the fusion state, whether the target is continuously in the fusion state is determined with reference to a detection history. When it is determined that the target is continuously in the fusion state, it is determined that the target is present at this position. Moreover, regarding the target that is in the fusion state, should the target be in a non-detectable state, the target is regarded as being at the previously detected position for a predetermined period of time with respect to the detection history.Regarding the target determined to be in this fusion state, pattern matching is performed using a pattern prepared in advance with respect to the second detection information. The target detection unit 11 then serves as a type determination means. The target detection unit 11 determines whether the target is a vehicle or a pedestrian, and assigns the determination to the target as a type. The concept of a pedestrian may also include people on bicycles.A traveling state calculation unit 12 determines the traveling state of the own vehicle 50 from detection results of the vehicle speed sensor 23, the link angle sensor 24, and the yaw rate sensor 25. Specifically, the traveling state calculation unit 12 calculates a motion amount in a lateral direction, a motion amount in a front-rear direction, and a rotation angle per unit time of the own vehicle 50 based on the vehicle speed, the yaw rate, and a vehicle center-of-gravity slip angle from the vehicle speed sensor 23, the steering angle sensor 24, and the yaw rate sensor 25. Therefore, detailed description thereof will be omitted.An angle calculation unit 30 calculates an axis misalignment angle which is a misalignment amount of a mounting angle of the radar device 21. The angle calculation unit 30 calculates an axis misalignment direction indicating whether the axis misalignment of the radar device 21 has occurred on the left side or the right side with respect to the own vehicle 50. Here, the calculation principle of the axis misalignment angle will be described. FIG. 3 is a diagram showing an aspect in which, during traveling of the own vehicle 50, a stationary object such as a roadside object moves with respect to the (relative to) own vehicle 50. FIG. 3 illustrates, at (a), a state in which the radar device 21 is properly mounted. An axis O (axis in the front-rear direction) of the own vehicle 50 and the optical axis X 2 of the radar device 21 coincide with each other. FIG. 3 illustrates, at (b), a state in which axis misalignment has occurred in the radar device 21. The misalignment by an angle θ is present between the axis O of the own vehicle 50 and the optical axis X 2.In the case shown at (a) in FIG. 3, in a straight traveling state of the own vehicle 50, a target corresponding to a stationary object (hereinafter referred to as a stationary target F) is directly approached to the own vehicle 50. In the case shown at (b) in FIG. 3, the stationary target F is erroneously detected as approaching the own vehicle 50 while traversing (diagonally moving) at the angle θ.The angle calculation unit 30 acquires axis misalignment information (angle misalignment information) of the radar device 21 from a movement trajectory on which the stationary target F moves with respect to the own vehicle 50. The acquired axle misalignment information is collected in a storage unit such as the RAM of the driving support ECU 10. The axis misalignment information stored in the storage unit shows a distribution (dispersion, standard deviation) as shown in FIG. 4, for example, due to the influence of external noise and the like.Here, the angle calculation unit 30 calculates the axis misalignment angle by statistically processing the history of the axis misalignment information. An angle corresponding to a center of gravity G in the distribution of the axis misalignment information in FIG. 4 is calculated as, for example, the axis misalignment angle. As a result, the effect of dispersion of the axis misalignment information can be reduced, and the calculation accuracy with respect to the axis misalignment angle of the radar device 21 can be improved.However, when the axis misalignment angle is calculated by statistically processing the history of the axis misalignment information, since the collection of the axis misalignment information immediately after starting the driving support ECU 10 is small, the axis misalignment angle cannot be calculated, or should the axis misalignment angle be calculated, the accuracy thereof is low. In FIG. 5, for example, the axis misalignment angle is in an intermediate state for a predetermined period of time (hereinafter, referred to as an initial period of time T 1) after starting the driving support ECU 10.Therefore, the angle calculation unit 30 sets the misalignment amount of the mounting angle of the radar device 21 to a predetermined angle (hereinafter, referred to as an initial angle) until the initial period T 1 has elapsed after the start of the driving support ECU 10. The initial angle is determined in advance as an axle misalignment amount when axle misalignment occurs during normal use of the own vehicle, instead of when a vehicle collision is presumed. After the elapse of the initial period T 1, the axis misalignment angle calculated based on the history of the axis misalignment information is output in a state where the axis misalignment has been collected to some extent.It may be determined whether the current time is within the initial period T 1 based on an acquisition count (number of acquisitions) of the axle misalignment information after starting the driving support ECU 10. That is, a central processing unit 15 determines that the present time is within the initial period T 1 when the acquisition number of the axis misalignment information is less than a predetermined first threshold A. The control processing unit 15 determines that the current time is within a period after the elapse of the initial period T 1 when the acquisition number of the axis misalignment information is equal to or greater than the first threshold A. The first threshold value A is set to, for example, n x 1000 times (n=1, 2,... ).An axis misalignment correction unit 31 corrects position information of the optical axis X 2 of the radar device 21 on the basis of the axis misalignment angle output from the angle calculation unit 30. As a result, the axis misalignment correction unit 31 corrects position information of the target recognized by the driving support ECU 10.The angle that can be corrected by the axis misalignment correction unit 31 is limited to a predetermined angle range (for example, an angle range corresponding to the range 61 that can be imaged by the imaging device 22). Therefore, when an axis misalignment equal to or greater than prescribed occurs in the radar device 21, a state in which the calculation value of the axis misalignment angle of the radar device 21 is equal to or greater than prescribed continues even when correction by the axis misalignment correction unit 31 is repeated. Therefore, according to the present embodiment, when the state in which the calculation value of the axis misalignment angle of the radar device 21 is equal to or greater than prescribed continues even when correction of the axis misalignment angle by the axis misalignment correction unit 31 is repeated, collision avoidance control by the driving support ECU 10 is prohibited or performed. The details of the determination of whether the collision avoidance control is performed will be described later.A regulation value calculation unit 13 sets a detection range R for detecting a target to be subjected to the collision avoidance control of the own vehicle 50 in front of the own vehicle 50. For example, as shown in FIG. 6 at (a), the detection range R is set as a range surrounded by a right regulation position XR, a left regulation position XL, and a front regulation position XF. The right regulation position XR is set further on the right side than the axis O in the front-rear direction of the own vehicle 50. The left regulation position XL is set further on the left side than the axis O. The front regulation position XF is set in front of the own vehicle 50. The front regulation position XF is set based on the vehicle speed of the own vehicle 50 or the like. The right regulation position XR and the left regulation position XL are set to coincide with the position of the lane in which the own vehicle 50 travels.As a result of the above, among the targets detected by the radar device 21, a target located outside the detection range R is not recognized as an object for collision avoidance by the driving support ECU 10. Specifically, targets that are located further on the right side than the right regulation position XR, further on the left side than the left regulation position XL, and further forward than the front regulation position XF with respect to the own vehicle 50 are not recognized as targets to be subjected to the collision avoidance control.Here, when the mounting direction of the radar device 21 is shifted in a horizontal direction (leftward or rightward direction) with respect to the own vehicle 50, an object (target) that is not present in front of the own vehicle 50 may be erroneously recognized as a target that is a control subject for the collision avoidance control. As shown in FIG. 6 at (c), for example, when the mounting direction of the radar device 21 is shifted to the right, a target P that is further on the right side than the right regulation position XR is erroneously recognized as a target that is a control subject for the collision avoidance control.Therefore, when axis misalignment exists in the radar device 21, the detection range R is narrowed based on a state of occurrence of the axis misalignment (axis misalignment direction and axis misalignment angle). As a result, erroneous determination of the target as a control object for the collision avoidance control can be prevented. In the example shown at (c) in FIG. 6, for example, when the right side (area on the right side with respect to the axis O of the own vehicle 50) of the detection area R is decreased, erroneous determination of the target P can be prevented.However, as described above, it takes to accurately calculate the axis misalignment angle of the radar device 21 by statistical processing. Therefore, in a state where the collection of the axis misalignment information is small and the determination accuracy regarding the axis misalignment of the radar device 21 is low, the axis misalignment angle cannot be calculated properly. In this case, the detection range R cannot be set appropriately based on the state of occurrence of the axle misalignment. Thus, erroneous operation of the collision avoidance control with respect to a target other than a control object cannot be prevented.Therefore, as shown in FIG. 6 at (b), the control processing unit 15 according to the present embodiment decreases the width in the lateral direction of the detection area R, that is, the width in the left-right direction with respect to the own vehicle 50, with left-right symmetry (initial mode). Specifically, the right regulation position XR and the left regulation position XL are each inclined in a direction (inward) approximating the axis O of the own vehicle 50 according to an initial angle α 0. As a result, the width in the transverse direction of the detection area R having left-right symmetry is reduced by the setting of the new regulation positions XR and XL. In this case, even if an axial misalignment in the left or right direction occurs in the radar device 21 during the initial period T 1 during which the identification of the axial misalignment direction of the radar device 21 is difficult, erroneous determination of a target that is not a control object as a target that is a control object and erroneous operation of the collision avoidance control with respect to the target that is not a control object can be prevented regardless of the axial misalignment direction of the radar device 21.Then, after the elapse of the initial period T 1, the angle calculation unit 30 may calculate the axis misalignment angle and the axis misalignment direction of the radar device 21 from the movement trajectory of the target as a result of the collection of the axis misalignment information. Here, in this case, the control processing unit 15 decreases the detection range R based on the calculation values of the axis misalignment angle and the axis misalignment direction (restriction mode).As shown in FIG. 4, the history of the axis misalignment information has a predetermined distribution (dispersion). The distribution (dispersion) of the axis misalignment information changes along with the calculation accuracy in the axis misalignment angle. Therefore, after the elapse of the initial period T 1, the control processing unit 15 decreases the detection range R in consideration of the distribution of the axis misalignment information. For example, the angle calculation unit 30 calculates an angle corresponding to 3 σ (99.73%) of the axis misalignment information by statistically processing the history of the axis misalignment information as a correction value (hereinafter, referred to as a statistical dispersion amount) (see FIG. 4 ). Then, the control processing unit 15 calculates an angle at which to decrease the detection range R using a sum of the calculated value of the axis misalignment angle and the statistical dispersion amount. In this way, when the angle by which the detection range R is to be decreased is calculated in consideration of the dispersion of the history of the axis misalignment information, the detection range R can be set more appropriately based on the calculation accuracy with respect to the axis misalignment angle at that time.In addition, in the restriction mode, the control processing unit 15 decreases the width of the detection range R in the lateral direction with left-right asymmetry with respect to the axis O of the own vehicle 50. As a result, the transverse direction of the detection range R is decreased by setting the new regulation position with left-right asymmetry.As shown in FIG. 6 at (c), for example, when an axis misalignment in the right direction occurs in the radar device 21, the right regulation position XR on the right side with respect to the axis O of the own vehicle 50 is inclined inward by an inclination angle α 1. As a result, a regulation position XR2 on the right side of the detection range R is reset. In this way, in the detection range R, when only the side corresponding to the axis misalignment direction of the radar device 21 is reduced, erroneous determination of the target which is the control subject can be prevented while the detection range R for the target in front of the own vehicle 50 is ensured.An operation determination unit 14 determines whether a target exists in the detection range R set by the regulation value calculation unit 13. When a target exists in the detection range R, the operation determination unit 14 calculates a collision prediction time that is the time to collision between the own vehicle 50 and the target. The collision prediction time is calculated based on, for example, the distance between the own vehicle 50 and the target and the relative speed.The control processing unit 15 compares the collision prediction time calculated by the operation determination unit 14 with an operation time set individually for each of the warning device 41, the braking device 42, and the seat belt device 43, which are the safety devices. Then, when the collision prediction time is less than the operation time of a safety device, the control processing unit 15 transmits a command signal to the corresponding safety device. As a result, a safety device of at least one of the warning device 41, the braking device 42, and the seat belt device 43 is operated, and the driver is notified of the risk of collision.In cases where the calculation value of the axis misalignment angle is outside the allowable range even when correction of the axis misalignment angle by the axis misalignment correction unit 31 is repeatedly performed, the control processing unit 15 prohibits the collision avoidance control. For example, when the axis misalignment angle after the elapse of a predetermined time period (also referred to as determination time period T 2) after the driving support ECU 10 is started is outside the allowable range, the control processing unit 31 prohibits the collision avoidance control. The determination period T 2 may be determined based on the acquisition number of the axis misalignment information since the starting, for example. The determination period T 2 is determined to be reached, for example, when the acquisition number of the axis misalignment information becomes equal to a second threshold B. The second threshold value B is set to, for example, n x 10,000 times (n=1, 2, 3,... ).Next, a setting process for the detection range R performed by the driving support ECU 10 will be described. FIG. 7 is a flowchart of the setting process for the detection range R. The process described below is performed at a predetermined cycle after turning on an ignition switch (not shown).In FIG. 7, the driving support ECU 10 determines whether the mode is the initial mode (step S 11). The result is positive when the acquisition number of the axis misalignment information is less than the first threshold A. When it is determined that the mode is the initial mode, the driving support ECU 10 decreases the detection range R having left-right symmetry by setting new regulation positions XR 1 and XL 1 of the detection range R by inclining the right regulation position XR and the left regulation position XL inward by an angle corresponding to the initial angle (step S 12).When the result in step S 11 is negative, the driving support ECU 10 determines whether the mode is the restriction mode (step S 13). The result is positive when the acquisition number of the axis misalignment information is equal to or greater than the first threshold A and less than the second threshold B. When it is determined that the mode is the restriction mode, the driving support ECU 10 determines whether the axis misalignment direction of the radar device 21 is the rightward direction (step S 14). The current process may be determined based on a calculation result of the movement trajectory of the target. When it is determined in step S 14 that the axis misalignment of the radar device 21 is in the right direction, the range on the right side with respect to the axis O of the own vehicle 50 is reduced by an angle calculated based on the axis misalignment angle and the statistical dispersion amount. That is, the detection range R is decreased by setting the regulation position XR 2 on the right side of the detection range R to a position where the right regulation position XR is inclined to the right. When the result in step S 14 is negative, that is, when the inclination direction of the radar device 21 is the leftward direction, the range on the left side with respect to the axis O of the own vehicle 50 is reduced using the axis misalignment angle calculated in consideration of the statistical dispersion amount. That is, the detection range R is decreased by re-setting the regulation position on the left side of the detection range R to a position where the left regulation position XL is inclined leftward by the inclination angle α 1 (step S 16). If the result in step S 13 is negative, the process is ended. In this case, the detection range R is not limited.An embodiment of the above-described process will be described below. In the following description, a state in which the optical axis X 2 of the radar device 21 is shifted rightward with respect to the axis O of the own vehicle 50 is assumed.When the driving support ECU 10 is started, acquisition of the axle misalignment information is started. Also, the mode is the initial mode. The width in the transverse direction of the detection range R is decreased with left-right symmetry based on the initial angle (see FIG. 6 at (b)). Then, it is determined whether to perform collision avoidance with respect to a target within the detection range R prescribed as the range within the regulation positions XR 1 and XL 2. Subsequently, when the calculation number for the axis misalignment angle becomes equal to or greater than the first threshold A, the mode shifts to the restriction mode. In the constraint mode, the axis misalignment direction of the radar device 21 is determined from the information on the movement trajectory of the target. Here, it is determined that the radar device 21 is axially displaced to the right. Therefore, the area on the right side with respect to the axis O of the own vehicle 50 is reduced (see FIG. 6 at (c)). Subsequently, when the axis misalignment angle of the radar device 21 is equal to or greater than prescribed, when the calculation number for the axis misalignment angle becomes equal to or greater than the second threshold B, the collision avoidance control is prohibited.Here, the radar apparatus 21 according to the present embodiment corresponds to a target detection device in the claims. The angle calculation unit 30 according to the present embodiment corresponds to acquisition means, calculation means, and means for calculating a statistical dispersion amount of the angle misalignment information in the claims. The regulation value calculation unit 13 corresponds to a detection range setting means in the claims. The control processing unit 15 according to the present embodiment corresponds to detection range restricting means and means for determining that the current time is within the initial time period in the claims.As a result of the above description, the following advantageous effects can be obtained.In the configuration in which the angle misalignment information of the radar device 21 is acquired at a predetermined cycle and the axis misalignment angle is calculated by statistically processing the history of the angle misalignment information after starting, until the predetermined initial time period has elapsed after starting, the axis misalignment angle is not known, or even when the axis misalignment angle is known, the accuracy thereof is low. Therefore, during the initial period, the width in the lateral direction of the detection range R in which the target to be subjected to the travel control of the own vehicle 50 is detected is decreased using the predetermined initial angle. In this case, even if an axle misalignment in the leftward or rightward direction occurs in the target detecting means during the initial period during which the accuracy of the axle misalignment angle is low, a target that is not present in front of the own vehicle can be prevented from being erroneously determined as a target to be subjected to the travel control of the own vehicle 50. In addition, in a state in which the initial period has elapsed and the detection of the axis misalignment angle and the axis misalignment direction of the target detection means becomes possible, the width in the transverse direction of the detection region R is decreased based on the axis misalignment angle and the axis misalignment direction. Therefore, based on the state of occurrence of the axle misalignment in the target detecting means, it can be prevented that a target that is not present in front of the own vehicle 50 is erroneously determined as a target to be subjected to the travel control.The detection range R is decreased with left-right symmetry until the initial time period has elapsed after starting. As a result, even if an axis misalignment in the leftward or rightward direction occurs in the target detecting means during the initial period while the arithmetic accuracy with respect to the axis misalignment angle is low, a target which is not present in front of the own vehicle can be prevented from being erroneously determined as a target to be subjected to the travel control.The history of the axis misalignment information has a predetermined distribution. Therefore, the side of the detection range R corresponding to the axis misalignment direction is reduced using the angle calculated based on the axis misalignment angle and the statistical dispersion amount of the angle misalignment information. In this case, the target detection range R after the elapse of the initial period may be set in consideration of the dispersion of the history of the axis misalignment information. The effect of preventing erroneous determination of the target to be subject to travel control can be improved.The present invention is not limited to the above description and can be carried out in the following manner.In the above description, the degree to which the width in the transverse direction of the detection area R is decreased in the initial mode can be variably set. When starting the driving support ECU 10, for example, the values of an acceleration sensor (not shown) mounted in the radar device 21 and an acceleration sensor (not shown) mounted in the vehicle are compared. When the information of both acceleration sensors coincide, the probability of axis misalignment in the radar device 21 is high. As shown in FIG. 8, the extent to which the width in the transverse direction of the detection area R is decreased is increased. In this case, when the probability of axis misalignment in the radar device 21 is high in the initial mode, the detection range R is further narrowed. The effect of preventing unnecessary travel control with respect to a target other than a control object can be improved.The above description is based on the assumption that axis misalignment in the horizontal direction has occurred in the radar device 21. However, in the radar device 21, axis misalignment may also occur in an up-down direction, or axis misalignment may occur in both the horizontal direction and the up-down direction. Therefore, the detection range R can be restricted in consideration of axis misalignment in the up-down direction of the radar device 21. For example, as shown in FIG. 9, when axis misalignment occurs in the up-down direction, a distance in a depth direction of the detection range R may be restricted. That is, the detection range R can be restricted by re-setting the position of the front regulation position XF to a position moved in a direction approaching the own vehicle 50.An example in which the presence of the axis misalignment angle of the radar device 21 is determined is described above. In addition, the above-described processes may be used for various types of target detection devices capable of detecting a target in front of the own vehicle 50 and calculating the distance between the own vehicle 50 and the target in front and a lateral position. The processes described above can be used for the imaging device 22 described above, for example.Above, the control mode is determined using the calculation number of the axis misalignment angle. However, the control mode may be determined based on an elapsed time from the start of the driving support ECU 10 or a travel distance from the start.Above, in the initial mode, the width in the lateral direction is reduced such that the detection range R has left-right symmetry with respect to the axis O of the own vehicle 50. In addition, the detection range R can be reduced with left-right asymmetry in the initial mode. For example, the extent to which a side located on the side of a reverse lane with respect to the own vehicle 50 is decreased may be increased.Above, in the constraint mode, a value corresponding to 3 σ of the axis misalignment information is calculated as the statistical dispersion amount. However, a value corresponding to σ or 2 σ of the axis misalignment information may be used as the statistical dispersion amount. The statistical scattering amount may be decreased, for example, as the computational accuracy for the axis misalignment angle increases.In the above-described restriction mode, when the radar device 21 is inclined leftward or rightward, the detection range R of the regulation position in the inclination direction of the radar device 21 can be restricted, and the detection range R of the regulation position on the side opposite to the inclination direction of the radar device 21 can be expanded within a range not exceeding the vehicle width of the own vehicle. In this case, control can be performed more accurately with respect to a target in front of the own vehicle while preventing unnecessary control with respect to an erroneously recognized target.Above, in the restriction mode, it may be determined whether the calculation value of the axis misalignment angle is within a predetermined allowable range (for example, 0.5 degrees). When the calculation value of the axis misalignment angle is determined to be outside the allowable angle, the detection range R can be reduced based on the calculation values of the axis misalignment angle and the axis misalignment direction. In this case, when the probability of axle misalignment in the radar device 21 is low, the collision avoidance control may be performed with priority with respect to the target. When the probability of axle misalignment in the radar device 21 is high, avoidance of erroneous determination of a target which is the control subject can be performed with priority.

Claims

A vehicle control apparatus (10) used for a vehicle in which a target detector (21) that detects a target in a vicinity of an own vehicle (50) is disposed, and that performs travel control of the vehicle on the basis of a detection result of the target detector, the vehicle control apparatus comprising: acquiring means for acquiring angular misalignment information of the target detector calculated on the basis of a detection position of the target by the target detector at a predetermined cycle; calculating means for calculating an axis misalignment angle, which is a misalignment amount of a mounting angle of the target detecting means, and an axis misalignment direction, which indicates a left or right side with respect to the own vehicle on which the axis misalignment of the target detecting means has occurred, by statistically processing a history after starting acquisition of the angle misalignment information by the acquiring means; detection range setting means for setting a detection range in front of the own vehicle in which a target to be subject to travel control of the own vehicle is detected from targets detected by the target detecting means; Detection range restricting means for reducing a width in a transverse direction of the detection range based on a predetermined initial angle which is the misalignment amount of the mounting angle of the target detecting means until a predetermined initial time period has elapsed after starting, and for reducing the width in the transverse direction of the detection range based on the axis misalignment angle and the axis misalignment direction calculated by the calculating means after the elapse of the initial time period after starting.The vehicle control apparatus according to claim 1, wherein the detection range restricting means decreases the detection range having left-right symmetry until the initial time period has elapsed after the starting.The vehicle control apparatus according to claim 1 or 2, further comprising: means for calculating a statistical amount of scattering of the angular misalignment information based on a result of statistical processing of the angular misalignment information acquired by the acquiring means, wherein the detection range restricting means decreases the width in the transverse direction of the detection range based on the axis misalignment angle of the target detecting means and the statistical amount of scattering after the elapse of the initial period.The vehicle control apparatus according to any one of claims 1 to 3, wherein the detection range restricting means decreases a side of the detection range corresponding to the axis misalignment direction calculated by the calculating means after the elapse of the initial period.The vehicle control apparatus according to any one of claims 1 to 4, further comprising: means for determining that a current time is within the initial period when an acquisition count after starting acquisition of the misalignment information by the acquisition means is less than a predetermined count.A vehicle control method performed by a vehicle control apparatus (10) used for a vehicle in which a target detector (21) that detects a target in a vicinity of an own vehicle (50) is disposed and that performs travel control of the vehicle based on a detection result of the target detector, the vehicle control method comprising: an acquisition step of acquiring angular misalignment information of the target detector calculated based on a detection position of the target by the target detector at a predetermined cycle; a calculation step of calculating an axis misalignment angle, which is a misalignment amount of a mounting angle of the target detector, and an axis misalignment direction, which indicates a left or right side with respect to the own vehicle on which the axis misalignment of the target detector has occurred, based on the angle misalignment information; a detection range setting step of setting a detection range in front of the own vehicle in which a target to be subject to travel control of the own vehicle is detected from targets detected by the target detector; a detection range restricting step of decreasing a width in a transverse direction of the detection range based on a predetermined initial angle which is the misalignment amount of the mounting angle of the target detection means until a lapse of a predetermined initial time period after starting, and decreasing the width in the transverse direction of the detection range based on the axis misalignment angle and the axis misalignment direction calculated in the calculating step after the lapse of the initial time period after starting.The vehicle control method according to claim 6, wherein the detection range limiting step decreases the detection range having left-right symmetry until the initial time period has elapsed after the starting.The vehicle control method according to claim 6 or 7, further comprising: a step of calculating a statistical amount of scattering of the angular misalignment information based on a result of statistical processing of the angular misalignment information acquired in the acquiring step, wherein the detection range restricting step decreases the width in the transverse direction of the detection range based on the axis misalignment angle of the target detecting means and the statistical amount of scattering after the elapse of the initial period.The vehicle control method according to any one of claims 6 to 8, wherein the detection range restricting step reduces a side of the detection range corresponding to the axis misalignment direction calculated in the calculating step after the elapse of the initial period.The vehicle control method according to any one of claims 6 to 9, further comprising: a step of determining that the current time is within the initial time period when an acquisition count after starting acquisition of the misalignment information by the acquisition step is less than a predetermined count.

Images