JP2011118819A - Driving support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving support device which can quickly and accurately estimate a lane change start time point. <P>SOLUTION: In the driving support device 1, a lane change estimation part 13 estimates a second time point at which a curvature change rate is a reference curvature change rate as a lane change start time point when a curvature change rate in a first time point at which direction indicator-ON is detected by a direction indicator sensor 3 is the reference curvature change rate or higher, so that the lane change start time point can be accurately estimated with consideration given to a delay of operation even if a direction indicator is operated after starting the lane change. Since the lane change start time point is estimated based on travel information already obtained when the direction indicator-ON is detected, the lane change start time point can be quickly estimated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a driving support device.

  2. Description of the Related Art Conventionally, as a driving support device, for example, as described in Japanese Patent Laid-Open No. 10-281776, a device that determines a lane change of a running vehicle based on a direction signal from a direction indicator and a yaw rate signal from a yaw rate sensor It has been known. In this device, while the direction signal indicates one of the left and right directions, the vehicle moving in the front direction starts turning in the same direction as the direction signal, then turns in the opposite direction, and again When the moving direction of the vehicle returns to the front, it is determined that the lane change has been performed.

  Based on such a lane change determination, it is determined whether or not the lane being traveled is a curve, and further, another lane is determined as to whether the preceding traveling vehicle is traveling in the same lane as the host vehicle. Determine if you are driving.

Japanese Patent Laid-Open No. 10-281776

  However, in the apparatus described in Patent Document 1, it is difficult to quickly determine the start point of the lane change because the lane change can be determined only after the vehicle has finished the lane change. In addition, when the operation timing of the direction indicator by the driver deviates from the lane change timing, the determination accuracy at the start of lane change may be reduced.

  Therefore, the present invention has been made to solve such a technical problem, and an object of the present invention is to provide a driving support device capable of quickly and accurately estimating the start time of lane change.

  That is, the driving support device according to the present invention calculates a direction indication detecting means for detecting a direction indication by a direction indicator, a host vehicle curvature that is a curvature of a traveling locus of the host vehicle, and calculates a curvature change speed of the host vehicle curvature. Vehicle curvature calculation means, lane change estimation means for estimating the lane change start time of the vehicle based on the direction indication detected by the direction indication detection means and the curvature change speed calculated by the vehicle curvature calculation means, The lane change estimation means has a curvature change speed that is the predetermined value when the curvature change speed at the first time point when the predetermined direction instruction is detected by the direction instruction detection means is greater than or equal to a predetermined value. The second time point is estimated as the lane change start time point.

  According to the driving support apparatus of the present invention, the lane change estimation means has a curvature change speed that is greater than or equal to a predetermined value when the curvature change speed at the first time point when the predetermined direction instruction is detected by the direction instruction detection means. The second time point that is the predetermined value is estimated as the lane change start time point. Normally, when the own vehicle starts to change lanes, the own vehicle curvature and the rate of change in curvature gradually increase. Here, when the curvature change speed is already equal to or greater than the predetermined value at the first time point when the direction indication is detected, it is possible that the operation of the direction indicator by the driver was later than the start of the lane change.

  In this case, since the lane change estimation means estimates the second time point when the curvature change speed was a predetermined value as the lane change start time point, even if the direction indicator is operated after the lane change start, The start point of the lane change can be accurately estimated in consideration of the operation delay. Further, since the start time of the lane change is estimated based on the travel information (curvature change speed) already obtained when the direction instruction is detected, the start time of the lane change can be quickly estimated.

  Moreover, in the driving assistance apparatus according to the present invention, the lane change estimation means is configured so that when the time difference between the first time point and the second time point is equal to or longer than a certain time, the lane change estimating means It is preferable to estimate the third time point as a lane change start time point.

  When the time difference between the first time point and the second time point is equal to or greater than a certain time, that is, the second time point when the curvature change speed is a predetermined value compared to the first time point when the predetermined direction indication is detected. Is a certain time or more before, at the second time point, it is considered that the driver operated the direction indicator with a great delay after starting the lane change. According to the above invention, the lane change estimating means estimates the third time point that is a certain time before the first time point as the lane change start time point. Even if there is, it is possible to accurately estimate the start time of the lane change.

  In the driving support device according to the present invention, the road curvature, which is the curvature of the road on which the vehicle travels during the lane change, is estimated based on the vehicle curvature at the lane change start time estimated by the lane change estimation unit. It is preferable to provide a road curvature estimation means.

  Usually, the vehicle curvature during the lane change is different from the road curvature due to the steering operation for changing the lane. On the other hand, it is considered that the vehicle curvature at the start of lane change approximates the road curvature. According to the above invention, the road curvature estimation means estimates the road curvature based on the vehicle curvature at the time when the lane change starts, so that the road curvature can be estimated with high accuracy.

  In the driving support device according to the present invention, it is preferable that the road curvature estimation means sets the vehicle curvature at the start of lane change as the road curvature.

  When the vehicle travels on a curved road with a substantially constant curvature, it is considered that the vehicle curvature at the start of lane change is substantially equal to the road curvature during the lane change. According to the above invention, it is possible to improve the estimation accuracy of the road curvature in the lane change while traveling on a curved road having a substantially constant curvature. Here, the curved road having a substantially constant curvature includes a straight road.

  Further, in the driving support device according to the present invention, based on the own vehicle direction detecting means for detecting the own vehicle direction that is the direction of the own vehicle, and the own vehicle direction at the lane change start time estimated by the lane change estimating means, It is preferable to include road direction estimation means for estimating a road direction that is the direction of the road on which the host vehicle travels while changing lanes.

  In order to accurately estimate the lane in which the host vehicle travels (hereinafter referred to as “own lane”), it is desirable to estimate not only the road curvature but also the road direction. Usually, the direction of the host vehicle during the lane change differs from the road direction by a steering operation for changing the lane. On the other hand, the host vehicle direction at the start of lane change is considered to approximate the road direction. According to the above invention, the road direction estimating means can estimate the road direction with high accuracy because the road direction is estimated based on the direction of the host vehicle at the start of lane change. Furthermore, the own lane can be estimated with high accuracy.

  In the driving support device according to the present invention, it is preferable that the road direction estimating means sets the direction of the own vehicle at the start of lane change as the road direction.

  According to the present invention, in the lane change while traveling on a straight road or a curved road with little change in direction, it is possible to improve the estimation accuracy of the road direction.

  According to the present invention, it is possible to quickly and accurately estimate the start time of lane change.

It is a block block diagram which shows the driving assistance device which concerns on embodiment of this invention. It is a flowchart which shows the process sequence of the lane change estimation process by the driving assistance device of FIG. It is explanatory drawing of lane change start time estimation. It is explanatory drawing of the other example of lane change start time estimation. It is explanatory drawing of the further another example of lane change start time estimation. It is a flowchart which shows the process sequence of the lane change completion estimation in FIG. It is explanatory drawing of lane change end time estimation. It is explanatory drawing of the other example of lane change end time estimation. It is explanatory drawing of the further another example of lane change end time estimation. It is a flowchart which shows the process sequence of the own lane center estimation process by the driving assistance device of FIG. It is explanatory drawing of the own lane center estimation. It is explanatory drawing of the other example of the own lane center estimation. It is explanatory drawing of the further another example of the own lane center estimation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant descriptions are omitted.

  FIG. 1 is a block configuration diagram illustrating a driving support apparatus according to an embodiment of the present invention. The driving assistance apparatus 1 according to the present embodiment is applied to an ACC (adaptive cruise control) system mounted on the host vehicle, estimates the lane change start time and the lane change end time of the host vehicle traveling on the road, and The direction and curvature of the road being changed (hereinafter referred to as “road direction” and “road curvature”, respectively) are estimated. Further, the driving support device 1 is based on the estimated road direction and road curvature, and is a curve (hereinafter referred to as “the vehicle width direction center” in the front part of the host vehicle and parallel to the center line of the host vehicle lane in front of the host vehicle. Estimate “center of own lane”). The own lane center estimated by the driving assistance device 1 is used for driving assistance such as, for example, determining whether a forward traveling vehicle is traveling in the same lane as the own vehicle.

  As shown in FIG. 1, the driving support device 1 includes a wheel speed sensor 2, a blinker sensor 3, a yaw rate sensor 4, a rudder angle sensor 5, a navigation system 6, and an own lane center estimation ECU (Electronic Control Unit) 10. Yes. Each of the wheel speed sensor 2, the blinker sensor 3, the yaw rate sensor 4, the rudder angle sensor 5, and the navigation system 6 is connected to the own lane center estimation ECU 10. The own lane center estimation ECU 10 is connected to a driving assistance ECU (not shown) that performs driving assistance using the estimation result of the own lane center.

  The wheel speed sensor 2 is a sensor that is provided on each wheel and detects a wheel speed pulse. The wheel speed sensor 2 detects a wheel speed pulse at each wheel, and outputs wheel speed pulse information indicating the detected wheel speed pulse to the own lane center estimation ECU 10.

  The winker sensor 3 is a sensor that detects a direction indication by a winker (direction indicator) operated by a driver, that is, a right winker ON, a left winker ON, or OFF. The blinker sensor 3 corresponds to a direction instruction detection unit. The blinker sensor 3 detects a direction instruction and outputs blinker information indicating the detected direction instruction to the own lane center estimation ECU 10.

  The yaw rate sensor 4 is a sensor that detects the yaw rate of the host vehicle. The yaw rate sensor 4 detects the yaw rate of the host vehicle, and outputs yaw rate information indicating the detected yaw rate to the host lane center estimation ECU 10.

  The steering angle sensor 5 is a sensor that is provided on a steering shaft (not shown) of the host vehicle and detects the steering angle of the steering (not shown) of the host vehicle. The steering angle sensor 5 detects the direction and magnitude of the steering angle, and outputs steering angle information indicating the detected steering angle direction and magnitude to the own lane center estimation ECU 10.

  The navigation system 6 includes a GPS (Global Positioning System) receiver and detects the direction of the host vehicle, which is the direction of the host vehicle. This navigation system 6 corresponds to the vehicle direction detection means. The navigation system 6 detects the host vehicle direction and outputs host vehicle direction information indicating the detected host vehicle direction to the host lane center estimation ECU 10. In addition, you may detect the own vehicle direction using the wheel speed pulse information by the wheel speed sensor 2 or the steering angle sensor 5, and steering angle information.

  The own lane center estimation ECU 10 estimates the own lane center by estimating the lane change start time and lane change end time of the own vehicle traveling on the road, and further the road direction and road curvature. The own lane center estimation ECU 10 is mainly configured by a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), for example. The own lane center estimation ECU 10 acquires information output from each of the wheel speed sensor 2, the blinker sensor 3, the yaw rate sensor 4, the steering angle sensor 5, and the navigation system 6, and performs predetermined processing based on the acquired information. By performing the above, the above estimation is performed.

  The own lane center estimation ECU 10 includes a travel information acquisition unit 11, an own vehicle curvature calculation unit 12, a lane change estimation unit 13, an own vehicle direction detection unit 14, a road curvature estimation unit 15, a road direction estimation unit 16, and an own lane center estimation. A portion 17 is provided.

  The travel information acquisition unit 11 acquires information output from each of the wheel speed sensor 2, the blinker sensor 3, the yaw rate sensor 4, the rudder angle sensor 5, and the navigation system 6, and stores each acquired information as travel information. . Here, the traveling information acquisition unit 11 stores each traveling information in association with the time when each traveling information is detected. The travel information acquisition unit 11 stores the stored travel for processing in the host vehicle curvature calculation unit 12, the lane change estimation unit 13, the host vehicle direction detection unit 14, the road curvature estimation unit 15, and the road direction estimation unit 16. Output information.

  Based on the wheel speed pulse information, yaw rate information, and steering angle information stored in the travel information acquisition unit 11, the host vehicle curvature calculation unit 12 calculates the host vehicle curvature, which is the curvature of the travel track of the host vehicle at each time. And a vehicle curvature calculation means for calculating a curvature change speed which is a change speed of the vehicle curvature. The own vehicle curvature calculation unit 12 stores the calculated own vehicle curvature and the curvature change speed in association with the time when each piece of travel information is detected.

  Further, the host vehicle curvature calculation unit 12 calculates a curvature change amount that is a change amount of the host vehicle curvature based on the host vehicle curvature at the start of lane change (hereinafter referred to as “lane change start curvature”). Note that the vehicle curvature, curvature change speed, and curvature change amount calculated and stored by the vehicle curvature calculation unit 12 are positive on the right in the traveling direction and negative on the left in the traveling direction with respect to the own vehicle.

  The lane change estimation unit 13 is a lane change estimation unit that estimates the lane change start time of the host vehicle based on the direction indication detected by the turn signal sensor 3 and the curvature change speed calculated by the host vehicle curvature calculation unit 12. is there. Further, the lane change estimation unit 13 estimates the lane change end point of the host vehicle based on the direction indication detected by the turn signal sensor 3 and the host vehicle curvature calculated by the host vehicle curvature calculation unit 12. The lane change estimation unit 13 stores the estimated lane change start time and lane change end time. Further, the lane change estimation unit 13 estimates and stores the lane change start curvature based on the estimated lane change start time.

  The lane change estimating unit 13 stores a lane changing flag indicating whether or not the host vehicle is changing lanes. Specifically, “1” is set in the lane changing flag while it is estimated that the lane is being changed. In addition, “0” is set during other periods. The lane change estimating unit 13 determines whether the lane changing flag is “1” or “0”.

  Furthermore, the lane change estimation unit 13 stores various reference values used in the processing described later. That is, the lane change estimation unit 13 stores a reference curvature change speed (predetermined value) VR0, fixed times T0 and T1, a curvature R1, and a predetermined range R2 of curvature. The reference curvature change speed (predetermined value) VR0 is a reference value for the curvature change speed. Further, the fixed time T0 is a reference value for a time width in which the curvature change speed is equal to or higher than the reference curvature change speed VR0, and the fixed time T1 is a reference value for an elapsed time after the blinker OFF is detected. is there. Further, the curvature R1 and the predetermined curvature range R2 are reference values for the vehicle curvature for estimating the end point of the lane change. Note that these reference values may be constant values determined in advance, or may be values that are appropriately set according to a traveling state such as a vehicle speed.

  The own vehicle direction detection unit 14 calculates the own vehicle direction at the time of starting the lane change (hereinafter referred to as “lane change start direction”) based on the own vehicle direction information stored in the travel information acquisition unit 11. It is a detection means. In addition, the host vehicle direction detection unit 14 calculates a direction change amount that is a change amount of the host vehicle direction based on the calculated lane change start direction. The host vehicle direction and the direction change amount calculated by the host vehicle direction detection unit 14 are positive on the right side of the traveling direction and negative on the left side of the traveling direction with reference to the host vehicle.

  The road curvature estimation unit 15 is a road curvature estimation unit that estimates the road curvature based on the lane change start curvature estimated by the lane change estimation unit 13. In addition, the road curvature estimation unit 15 stores a constant value DR0 used in the processing described later. The road curvature estimation unit 15 determines whether or not the curvature change amount calculated by the host vehicle curvature calculation unit 12 is less than a predetermined value DR0. This constant value DR0 is a value that is set as the amount of change in the vehicle curvature that normally occurs when the lane is changed.

  The road direction estimation unit 16 is a road direction estimation unit that estimates the road direction based on the lane change start direction calculated by the host vehicle direction detection unit 14. In addition, the road direction estimation unit 16 stores a constant value DY0 used in processing described later. The road direction estimation unit 16 determines whether or not the direction change amount calculated by the host vehicle direction detection unit 14 is less than a certain value DY0. This constant value DY0 is a value that is set as the amount of change in the direction of the host vehicle that normally occurs when the lane is changed.

  The own lane center estimation unit 17 estimates the own lane center based on the road curvature estimated by the road curvature estimation unit 15 and the road direction estimated by the road direction estimation unit 16. The own lane center estimating unit 17 outputs information indicating the estimation result of the own lane center to a driving support ECU (not shown) or the like.

  Then, operation | movement of the driving assistance apparatus 1 which has the above structure is demonstrated. First, the estimation process of the lane change start time and the lane change end time by the driving support device 1 will be described. FIG. 2 is a flowchart illustrating a processing procedure of the lane change estimation process. The process in FIG. 2 is repeatedly executed at a predetermined cycle by the own lane center estimation ECU 10.

  First, in step S <b> 1, travel information is acquired by the travel information acquisition unit 11. Here, information output from each of the wheel speed sensor 2, the blinker sensor 3, the yaw rate sensor 4, the rudder angle sensor 5, and the navigation system 6 is acquired and sequentially stored.

  Next, the process proceeds to step S <b> 2, and the host vehicle curvature calculation unit 12 calculates the host vehicle curvature and the curvature change speed. Further, the calculated vehicle curvature and curvature change speed are sequentially stored.

  Next, the process proceeds to step S3, and the lane change estimating unit 13 determines whether or not the lane changing flag is set to “0”. Here, it is determined whether the flag of the lane change estimating unit 13 is set to “0” or “1”.

  If it is determined in step S3 that the lane changing flag is set to “0”, the process proceeds to step S4, and the travel information acquisition unit 11 determines ON / OFF of the winker (right winker or left winker). . Here, the latest blinker information stored in the travel information acquisition unit 11 is used.

  On the other hand, if it is determined in step S3 that the lane change flag is set to “1”, the process proceeds to step S5, and the lane change end determination is performed. The procedure for determining whether to end the lane change will be described later.

  If it is determined in step S4 that the winker is ON (right winker ON or left winker ON), the process proceeds to step S6, and the lane change estimating unit 13 sets “1” in the lane change flag. If it is determined in step S4 that the winker is OFF, the process shown in FIG. 2 is terminated.

  Next, the process proceeds to step S7, and the lane change estimating unit 13 determines whether or not the curvature change speed is less than the reference curvature change speed VR0. Here, the curvature change speed at the time (first time point) when the turn signal ON is detected by the turn signal sensor 3 among the curvature change speeds stored in the vehicle curvature calculation unit 12 is used.

  If it is determined in step S7 that the curvature change speed is less than the reference curvature change speed VR0, the process proceeds to step S8, and the time when the turn signal ON is detected by the lane change estimation unit 13 is the start time of the lane change. The host vehicle curvature at that time is estimated to be the lane change start curvature. Then, the process shown in FIG.

  FIG. 3 is an explanatory diagram of lane change start time point estimation in steps S7 and S8. In FIG. 3, the turn-on / off of the winker, the curvature of the host vehicle, and the change over time of the curvature change speed are respectively shown from the top. In FIG. 3, “change in lane” indicates the true time zone in which the lane change is being performed (the same applies to FIGS. 4, 5, and 7 to 9). In the example shown in FIG. 3, the curvature change speed is less than the reference curvature change speed VR0 at time t1 when the winker ON is detected. Therefore, in step S8, the host vehicle curvature CS1 at time t1 is estimated to be the lane change start curvature. Thus, by the estimation process in step S8, it is estimated that the time t1 approximated to the true lane change start time is the lane change start time.

  On the other hand, when it is determined in step S7 that the curvature change speed is equal to or higher than the reference curvature change speed VR0, the process proceeds to step S9, and the lane change estimation unit 13 sets the curvature change speed to be equal to or higher than the reference curvature change speed VR0. It is determined whether or not the time width is less than a certain time T0. Here, the time width in which the curvature change speed is equal to or higher than the reference curvature change speed VR0 includes the time when the curvature change speed is the reference curvature change speed VR0 (second time point) and the time when winker ON is detected ( It is calculated as a time difference from the first time).

  If it is determined in step S9 that the time width during which the curvature change speed is equal to or greater than the reference curvature change speed VR0 is less than the predetermined time T0, the process proceeds to step S10, and the lane change estimation unit 13 determines the curvature change speed as the reference. It is estimated that the time at which the curvature change speed VR0 was reached is the start time of the lane change, and the vehicle curvature at that time is estimated to be the lane change start curvature. Then, the process shown in FIG.

  FIG. 4 is an explanatory diagram of lane change start time point estimation in steps S7, S9, and S10. In the example shown in FIG. 4, the curvature change speed is equal to or higher than the reference curvature change speed VR0 at time t1 when the blinker ON is detected. Further, the time width in which the curvature change speed is equal to or higher than the reference curvature change speed VR0, that is, the time difference between the time t1 and the time t2 is less than the predetermined time T0. Therefore, in step S10, the host vehicle curvature CS2 at time t2 is set as the lane change start curvature. As described above, the estimation process in step S10 enables accurate estimation even in an operation (driver) in which the winker is started during the lane change.

  If it is determined in step S9 that the time width during which the curvature change speed is equal to or higher than the reference curvature change speed VR0 is equal to or longer than the predetermined time T0, the process proceeds to step S11, and the lane change estimation unit 13 turns the winker ON. It is estimated that the time (third time point) before the detected time is a predetermined time T0 is the start time of the lane change, and the own vehicle curvature at that time is estimated to be the lane change start curvature. Then, the process shown in FIG.

  FIG. 5 is an explanatory diagram of lane change start time point estimation in steps S7, S9, and S11. In the example shown in FIG. 5, at the time t1 when the blinker ON is detected, the curvature change speed is equal to or higher than the reference curvature change speed VR0. Further, the time width in which the curvature change speed is equal to or higher than the reference curvature change speed VR0, that is, the time difference Ta between the time t1 and the time t2 is equal to or greater than the predetermined time T0. Therefore, in step S11, the host vehicle curvature CS3 at time t3, which is a predetermined time T0 before time t1, is set as the lane change start curvature. As described above, the estimation process in step S11 enables accurate estimation even in an operation (driver) that starts the winker far from the lane change start time (largely behind).

  Next, the estimation process at the time of lane change end in step S5 will be described. FIG. 6 is a flowchart showing a processing procedure of lane change end estimation in FIG.

  First, in step S51, the lane change estimating unit 13 determines whether or not a predetermined time T1 has elapsed since the blinker OFF was detected. Here, based on the winker information stored in the travel information acquisition unit 11, the time difference from the time when the winker OFF is detected for the first time after the winker ON is detected to the present time is calculated, and this time difference is equal to or greater than a certain time T1. Judgment is made by whether or not.

  If it is determined in step S51 that the predetermined time T1 or more has elapsed since the blinker OFF was detected, the process proceeds to step S54, and the lane change estimation unit 13 estimates the lane change end point.

  FIG. 7 is an explanatory diagram for estimating the lane change end point when the process proceeds from step S51 to step S54. In the example shown in FIG. 7, a certain time T1 or more has elapsed since time t4 when the blinker OFF was detected. In this case, in step S54, it is estimated that the time t5 after a certain time T1 from when the blinker OFF is detected is the end point of the lane change. With such an estimation process, it is possible to estimate with high accuracy even in an operation (driver) that turns off the blinker during a lane change.

  If it is determined in step S51 that the predetermined time T1 or more has not elapsed since the detection of the turn signal OFF, the process proceeds to step S52, and the lane change estimation unit 13 determines whether or not the lane change is completed. Determined by judgment. In this first end determination, after the vehicle curvature has changed in the left-right direction by a certain value or more from the lane change start curvature CS1 (or CS2, CS3) estimated in step S8 (or steps S10, S11), Judgment is made based on whether or not the vehicle curvature has returned to the vicinity of the lane change start curvature.

  When it is determined in step S52 that the lane change has been completed by the first end determination, the process proceeds to step S54, and the lane change estimation unit 13 estimates the lane change end point.

  FIG. 8 is an explanatory diagram for estimating the lane change end point when the process proceeds from step S52 to step S54. In the example shown in FIG. 8, the vehicle curvature has returned to the vicinity of the lane change start curvature again after the vehicle curvature has changed from the lane change start curvature CS <b> 1 estimated in step S <b> 8 to a certain value R <b> 0 or more and in the left-right direction. . Specifically, at time t6 and time t7, the own vehicle curvature changes from the lane change start curvature CS1 to a certain value R0 or more, rightward (positive side) and leftward (negative side). Then, at time t8, the vehicle curvature returns until the absolute value of the difference from the lane change start curvature CS1 reaches a predetermined curvature R1. In this case, in step S54, it is estimated that the time t8 is the end point of the lane change. With such an estimation process, it is possible to estimate with high accuracy even in an operation (driver) that turns off the blinker after the lane change is completed.

  If it is determined in step S52 that the lane change has not ended, the process proceeds to step S53, and the lane change estimation unit 13 determines whether or not the lane change has ended by a second end determination. In this second end determination, after the vehicle curvature changes in the left-right direction by a certain value or more from the lane change start curvature CS1 (or CS2, CS3) estimated in step S8 (or steps S10, S11), the host vehicle A determination is made based on whether or not the curvature has converged within a predetermined range for a predetermined time.

  If it is determined in step S53 that the lane change has been completed by the second end determination, the process proceeds to step S54, and the lane change estimation unit 13 estimates the lane change end point.

  FIG. 9 is an explanatory diagram for estimating the lane change end point when the process proceeds from step S53 to step S54. In the example illustrated in FIG. 9, the vehicle curvature has converged within a predetermined range for a predetermined time after the vehicle curvature has changed in the left-right direction by a certain value R0 or more from the lane change start curvature CS1 estimated in step S8. Specifically, at time t6 and time t7, the own vehicle curvature changes from the lane change start curvature CS1 to a certain value R0 or more, rightward (positive side) and leftward (negative side). And while the predetermined time T2 passes from the time t9 to the time t10, the own vehicle curvature has converged in the predetermined range R2. In this case, in step S54, it is estimated that the time t10 is the end point of the lane change. With such an estimation process, even if the actual road curvature changes during the lane change, and the own vehicle curvature at the lane change start time and the lane change end time are different, accurate estimation can be performed. Become.

  Next, the process proceeds to step S55, where the lane change estimating unit 13 sets “0” to the lane changing flag, and the lane change end estimation process of FIG. 6 is ended.

  Then, the estimation process of the own lane center by the driving assistance apparatus 1 is demonstrated. FIG. 10 is a flowchart illustrating a processing procedure of the own lane center estimation process. The process in FIG. 10 is repeatedly executed at a predetermined cycle by the own lane center estimation ECU 10. This own lane center estimation process is executed using travel information, curvature change speed, lane change start time, lane change start curvature, etc. acquired or calculated in the lane change estimation process of FIG.

  First, in step S21, the lane change estimating unit 13 determines whether or not the lane changing flag is set to “1” in order to determine whether or not the lane is being changed. Here, it is determined whether the flag of the lane change estimating unit 13 is set to “0” or “1”.

  If it is determined in step S21 that the lane changing flag is set to “1”, the process proceeds to step S22, and the vehicle curvature calculation unit 12 calculates the curvature change amount. Here, the curvature change amount is calculated for the latest vehicle curvature stored in the travel information acquisition unit 11. This curvature change amount is a value indicating how much the vehicle curvature has changed after the start of lane change.

  Next, the process proceeds to step S <b> 23, and the direction change amount is calculated by the own vehicle direction detection unit 14. Here, the lane change start direction is calculated based on the host vehicle direction information stored in the travel information acquisition unit 11, and the direction change amount is calculated for the latest host vehicle direction stored in the travel information acquisition unit 11. This direction change amount is a value indicating how much the direction of the vehicle has changed after the start of lane change.

  Next, the process proceeds to step S24, and the vehicle curvature calculation unit 12 determines whether or not the winker direction and the curvature change direction are the same. Here, the determination is made based on the latest blinker information stored in the travel information acquisition unit 11 and the latest curvature change speed stored in the host vehicle curvature calculation unit 12. For example, when the direction indication shown in the turn signal information is “right turn signal ON” and a rightward curvature change (positive curvature change) occurs, it is determined that the turn signal direction and the curvature change direction are the same. Further, when the direction indication shown in the turn signal information is the left turn signal ON, and the curvature change to the right occurs, it is determined that the turn signal direction is different from the curvature change direction.

  If it is determined in step S24 that the winker direction and the curvature change direction are the same, the process proceeds to step S25, and whether the curvature change amount calculated in step S22 by the road curvature estimation unit 15 is less than the constant value DR0. It is determined whether or not.

  If it is determined in step S25 that the curvature change amount is less than the constant value DR0, the process proceeds to step S26, and the road curvature estimation unit 15 estimates that the lane change start curvature is the road curvature. That is, the lane change start curvature is substituted into the road curvature. By such an estimation process, the road curvature can be accurately estimated even when the vehicle curvature and the road curvature are different during the lane change.

  On the other hand, if it is determined in step S25 that the amount of curvature change is equal to or greater than the constant value DR0, the process proceeds to step S27, and the road curvature estimation unit 15 subtracts the constant value DR0 from the vehicle curvature used in step S22. The value is estimated to be road curvature. That is, a value obtained by subtracting the own vehicle curvature change amount DR0 that normally occurs when the lane is changed from the own vehicle curvature is substituted into the road curvature. In other words, the road curvature estimation unit 15 sets a value obtained by adding a value ((curvature change amount) − (constant value DR0)) in which the curvature change amount exceeds the constant value DR0 to the lane change start curvature as the road curvature. . By such an estimation process, even when the road curvature changes during the lane change, the change is added to the lane change start curvature, so the road curvature can be estimated with high accuracy.

  Subsequent to step S26 or step S27, the process proceeds to step S28, and the road direction estimation unit 16 determines whether or not the direction change amount calculated in step S23 is less than a certain value DY0.

  If it is determined in step S28 that the direction change amount is less than the fixed value DY0, the process proceeds to step S29, and the road direction estimation unit 16 estimates that the value obtained by subtracting the direction change amount from the vehicle direction is the road direction. Is done. That is, the lane change start direction is substituted for the road direction. By such an estimation process, the road direction can be accurately estimated even when the vehicle direction and the road direction are different during lane change.

  On the other hand, if it is determined in step S28 that the direction change amount is equal to or greater than the constant value DY0, the process proceeds to step S30, and the road direction estimation unit 16 subtracts the constant value DY0 from the host vehicle direction used in step S23. The value is estimated to be road direction. That is, a value obtained by subtracting the own vehicle direction change amount DY0 that normally occurs when the lane is changed from the own vehicle direction is substituted for the road direction. In other words, the road direction estimation unit 16 sets a value obtained by adding a direction change amount exceeding a certain value DY0 ((direction change amount) − (constant value DY0)) to the lane change start direction. . By such an estimation process, even if the road direction changes during the lane change, the change is added to the lane change start direction, so the road direction can be estimated with high accuracy.

  Subsequent to step S29 or step S30, the process proceeds to step S31, and the own lane center estimation unit 17 estimates the own lane center. Here, the own lane center is estimated based on the road curvature estimated by the road curvature estimation unit 15 and the road direction estimated by the road direction estimation unit 16. And the own lane center estimation process of FIG. 10 is complete | finished.

  FIG. 11 is an explanatory diagram of the estimation of the own lane center when the lane is changed while traveling on a straight road. In the example shown in FIG. 11, the host vehicle 20 changes the lane to the right (overtaking lane) while traveling on a straight road. In FIG. 11, the own vehicle 20 at the start of lane change is shown on the left side, and the own vehicle 20 in the lane change start is shown on the right side (the same applies to the following drawings). As shown in FIG. 11, when the vehicle 20 traveling straight starts to change lanes, the lane change start curvature and the lane change start direction are the road curvature and the road direction, respectively (S26, S29), and the own lane center L1 Is estimated (S31).

  In addition, even during the lane change, since the road to travel is a straight road, the curvature change amount and the direction change amount are less than the constant values DR0 and DY0, respectively, and the lane change start curvature and the lane change start direction are respectively the road curvature and The road direction is set (S26, S29). Then, the own lane center L4 is estimated (S31).

  Here, when the own vehicle lane center is estimated based on the actual own vehicle curvature, the own vehicle curvature during the lane change is different from the road curvature, and therefore, the actual own lane like the own lane center L2 in FIG. It will deviate greatly from the center. In addition, even when the lane change start curvature is used as the road curvature, when the own lane center is estimated based on the actual own vehicle direction, the own vehicle direction during the lane change is different from the road direction. Like the own lane center L3, it will deviate from the actual own lane center.

  In the driving support device 1, when the curvature change amount and the direction change amount are less than the fixed values DR0 and DY0, respectively, the road curvature estimation unit 15 and the road direction estimation unit 16 set the lane change start curvature and the lane change start direction to the road curvature, respectively. And the road direction. For this reason, deviations such as the own lane center L2 and the own lane center L3 can be corrected, and the own lane center can be estimated with high accuracy. Even when the lane is changed during traveling on a curved road having a substantially constant curvature, the same effect can be obtained.

  FIG. 12 is an explanatory diagram of the estimation of the own lane center when the road curvature and the road direction change during the lane change. In the example shown in FIG. 12, the host vehicle 20 starts a lane change to the right (overtaking lane) while traveling on a straight road, and then the road curves to the right during the lane change. The own lane center L5 shown in FIG. 12 is estimated similarly to the case shown in FIG. Further, since the road becomes a curved road during the lane change, the curvature change amount and the direction change amount are both constant values DR0 and DY0 or more, and the constant values DR0 and DY0 are respectively subtracted from the actual own vehicle curvature and own vehicle direction. Are estimated to be the road curvature and the road direction (S27, S30). Then, the own lane center L8 is estimated (S31).

  Here, when the own lane center is estimated by the same procedure as the method shown in FIG. 11, the road curvature changes during the lane change, so that the actual own lane center L6 in FIG. It will deviate greatly from the center of the lane. Further, even when a value obtained by subtracting the constant value DY0 from the actual own vehicle direction is used as the road direction, when the lane change start curvature is used as the road curvature, the own vehicle curvature during the lane change is constant from the lane change start curvature. Since it has changed by the value DR0 or more, it will deviate from the actual own lane center like the own lane center L7 in FIG.

  In the driving support device 1, when both the curvature change amount and the direction change amount are equal to or greater than the constant values DR0 and DY0, the road curvature estimation unit 15 and the road direction estimation unit 16 determine the constant value DR0, from the own vehicle curvature and the own vehicle direction. The values obtained by subtracting DY0 are the road curvature and the road direction. For this reason, deviations such as the own lane center L6 and the own lane center L7 can be corrected, and the own lane center can be accurately estimated.

  On the other hand, if it is determined in step S21 that the lane change flag is set to “0”, or if it is determined in step S24 that the winker direction is different from the curvature changing direction, the process proceeds to step S32, and road curvature estimation is performed. The latest vehicle curvature stored in the travel information acquisition unit 11 is estimated by the unit 15 as the road curvature. That is, the latest vehicle curvature is substituted into the road curvature. By such an estimation process, even when the actual road curvature changes in the direction opposite to the lane change direction during the lane change, the road curvature can be accurately estimated.

  Next, the process proceeds to step S33, where the road direction estimation unit 16 estimates that the latest vehicle direction stored in the travel information acquisition unit 11 is the road direction. That is, the latest own vehicle direction is substituted for the road direction. By such an estimation process, the road direction can be accurately estimated even when the actual road direction changes in the direction opposite to the lane change direction during the lane change.

  Next, the process proceeds to step S31, where the own lane center estimating unit 17 estimates the own lane center, and the own lane center estimating process in FIG.

  FIG. 13 is an explanatory diagram of the estimation of the own lane center when the road curvature and the road direction change in the direction opposite to the lane change direction during the lane change. In the example shown in FIG. 13, the host vehicle 20 starts changing lanes to the left (traveling lane) while traveling on a straight road, and then the road curves to the right while changing lanes. The own lane center L9 shown in FIG. 13 is estimated similarly to the case shown in FIG. Further, during the lane change, since the road becomes a curved road in the direction opposite to the lane change direction, it is determined that the winker direction and the curvature change direction are different (S24). And it is estimated that it is a road direction (S32, S33). Then, the own lane center L12 is estimated (S31).

  Here, when the own lane center is estimated by the same procedure as the method shown in FIG. 11 and FIG. 12, the road curvature and the road direction are changed in the direction opposite to the lane change direction during the lane change. Like the own lane center L10 in FIG. 13, the actual lane center is greatly deviated. Even when the actual vehicle direction is used as the road direction, when the own lane center is estimated based on the lane change start curvature, the actual lane center is deviated from the actual lane center as shown in FIG. End up.

  In the driving support device 1, when it is determined that the winker direction and the curvature change direction are different, the vehicle curvature and the vehicle direction are set to the road curvature and the road direction by the road curvature estimation unit 15 and the road direction estimation unit 16, respectively. The For this reason, even when the amount of curvature change and the amount of direction change are small, the center of the own lane can be accurately estimated. Even when the lane is not being changed, the own vehicle curvature and the own vehicle direction are similarly estimated to be the road curvature and the road direction, respectively, so that the own lane center can be accurately estimated.

  By the series of processes described above, the lane change estimation process and the own lane center estimation process by the driving support device 1 are executed.

  As described above, according to the driving assistance apparatus 1 according to the present embodiment, the lane change estimation unit 13 has the curvature change speed at the first time point t1 when the turn signal ON is detected by the turn signal sensor 3 equal to or higher than the reference curvature change speed VR0. In this case, the second time point t2 at which the curvature change speed is the reference curvature change speed VR0 is estimated as the lane change start time (see FIG. 4). Normally, when the own vehicle starts to change lanes, the own vehicle curvature and the rate of change in curvature gradually increase. Here, when the curvature change speed is already equal to or higher than the reference curvature change speed VR0 at the first time point t1 when the winker ON is detected, it is considered that the driver's operation of the winker is later than the start of the lane change. .

  In this case, the lane change estimation unit 13 estimates the second time point t2 at which the curvature change speed is the reference curvature change speed VR0 as the lane change start time, and therefore, the winker is operated after the lane change start. However, it is possible to accurately estimate the start time of the lane change in consideration of the operation delay. Further, since the start time t2 of the lane change is estimated based on the travel information (curvature change speed) already obtained when the blinker ON is detected, the start time t2 of the lane change can be quickly estimated.

  Further, when the time difference Ta between the first time point t1 and the second time point t2 is equal to or greater than the predetermined time T0, that is, the curvature change speed is the reference curvature change speed from the first time point t1 when the winker ON is detected. When the second time point t2 that is VR0 is more than a predetermined time T0, it is considered that at the second time point t2, the driver operated the blinker with a great delay after starting the lane change. According to the driving support device 1, the lane change estimation unit 13 estimates the third time point t3, which is a predetermined time T0 before the first time point t1, as the lane change start time point. Even if it is made, the start time of the lane change can be accurately estimated (see FIG. 5).

  Further, usually, the vehicle curvature during the lane change differs from the road curvature due to a steering operation for changing the lane. On the other hand, it is considered that the vehicle curvature at the start of lane change approximates the road curvature. According to the driving support device 1, the road curvature estimation unit 15 can estimate the road curvature with high accuracy because the road curvature is estimated based on the own vehicle curvature at the time of starting the lane change.

  Further, when the vehicle travels on a curved road (including a straight road) with a substantially constant curvature, the vehicle curvature at the start of lane change is considered to be substantially equal to the road curvature during the lane change. According to the driving assistance apparatus 1, in the lane change while driving on a curved road having a substantially constant curvature, it is possible to increase the estimation accuracy of the road curvature.

  Moreover, in order to estimate the own lane center with high accuracy, it is desirable to estimate not only the road curvature but also the road direction. Usually, the direction of the host vehicle during the lane change differs from the road direction by a steering operation for changing the lane. On the other hand, the host vehicle direction at the start of lane change is considered to approximate the road direction. According to the driving support device 1, the road direction estimating means estimates the road direction based on the direction of the host vehicle at the time of starting the lane change, so that the road direction can be estimated with high accuracy. Furthermore, the own lane center L4 can be accurately estimated (see FIG. 11).

  Moreover, according to the driving assistance apparatus 1, in the lane change while driving | running | working the straight road or the curve road with few changes of a direction, the estimation precision of a road direction can be improved.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited to the said embodiment. For example, in the above embodiment, the case where the estimation result of the lane change is used for estimation of the center of the own lane has been described. However, other driving assistance such as driving assistance for preventing a collision with another vehicle traveling in the adjacent lane is described. May be used.

  DESCRIPTION OF SYMBOLS 1 ... Driving assistance device, 3 ... Winker sensor (direction instruction | indication detection means), 12 ... Own vehicle curvature calculating part (own vehicle curvature calculating means), 13 ... Lane change estimation part (lane change estimation part means), 14 ... Own vehicle Direction detection unit (own vehicle direction detection unit) 15 ... road curvature estimation unit (road curvature estimation unit), 16 ... road direction estimation unit (road direction estimation unit), 20 ... own vehicle, T0 ... fixed time, t1 ... time ( First time), t2 ... time (second time), t3 ... time (third time), Ta ... time difference, VR0 ... reference curvature change speed (predetermined value).

Claims (6)

Direction indication detection means for detecting a direction indication by a direction indicator;
A host vehicle curvature calculating means for calculating a host vehicle curvature that is a curvature of a traveling locus of the host vehicle, and calculating a curvature change speed of the host vehicle curvature;
Lane change estimating means for estimating a lane change start time of the own vehicle based on the direction indication detected by the direction indication detecting means and the curvature change speed calculated by the own vehicle curvature calculating means. ,
The lane change estimation means has the curvature change speed equal to the predetermined value when the curvature change speed at a first time point when the predetermined direction instruction is detected by the direction instruction detection means is greater than or equal to a predetermined value. A driving support device characterized in that a second time point is estimated as the lane change start time point.   When the time difference between the first time point and the second time point is equal to or longer than a predetermined time, the lane change estimating unit determines a third time point that is a predetermined time before the first time point as the lane. The driving support device according to claim 1, wherein the driving support device is estimated to be a change start time.   A road curvature estimation unit that estimates a road curvature that is a curvature of a road on which the host vehicle travels during a lane change based on the host vehicle curvature at the lane change start time estimated by the lane change estimation unit. Item 3. The driving support device according to Item 1 or 2.   The driving assistance device according to claim 3, wherein the road curvature estimation means sets the vehicle curvature at the time of starting the lane change as the road curvature. A host vehicle direction detecting means for detecting a host vehicle direction which is a direction of the host vehicle;
Road direction estimating means for estimating a road direction that is the direction of the road on which the own vehicle travels during lane change based on the own vehicle direction at the start time of the lane change estimated by the lane change estimating means; The driving assistance device according to any one of claims 1 to 4.   The driving support device according to claim 5, wherein the road direction estimating means sets the direction of the host vehicle at the time when the lane change is started as the road direction.

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