JP2022060073A - Vehicle drive support device - Google Patents

Abstract

To provide a vehicle drive support device which can realize emergency avoidance by steering for an object without generating excessive lateral acceleration.SOLUTION: An automatic drive control unit 26 repeats update of a lateral jerk J_n a set number of times (for example, n=10) by using a binary search method with a maximum lateral jerk (maximum lateral acceleration) permitted according to the own vehicle speed in steering control as a reference value, calculates a collision avoidance time t_Rap0 to the time when collision with an obstacle O can be avoided when steering control of moving an own vehicle M to the target lateral position on the basis of the lateral jerk J_n every time the lateral jerk J_n is updated, and sets the lateral jerk J_n (minimum lateral jerk) for realizing the maximum collision avoidance time t_Rap0 out of the collision avoidance times t_rap0 equal to or less than a threshold Tth_Rap0 set on the basis of a collision allowance time TTC as an optimum lateral jerk J.SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle driving support device capable of performing collision avoidance control by steering intervention for an obstacle existing in front of the own vehicle.

In recent years, in vehicles such as automobiles, various technologies for driving support that reduce the burden on the driver and enable comfortable and safe driving have been proposed and put into practical use.

This type of driving support is equipped with an Adaptive Cruise Control (ACC) function and a Lane Keeping (Lane Keeping) function, so that the vehicle can maintain the distance from the preceding vehicle and follow the driving lane. Can be run automatically. Furthermore, by providing a locator function, it is possible to automatically drive the own vehicle to the destination.

In such a driving support device, in lane keeping control, a front recognition device such as a stereo camera mounted on the vehicle is used to recognize the lane marking that divides the left and right of the lane in which the own vehicle is traveling, and the own. Steering control is performed so that the vehicle runs in the center of the left and right lane markings.

Further, in this type of driving support device, when lane keeping control or the like is executed, if a collision cannot be avoided by braking control (emergency braking, etc.) against an obstacle existing in front of the driving path of the own vehicle, steering intervention is performed. Techniques have been proposed for going and avoiding emergency collisions with obstacles. For example, in Patent Document 1, based on the relationship between the vehicle speed and the lateral acceleration set in advance for a normal turn, the area around the vehicle (particularly in front) is supported as an area where a collision cannot be easily avoided by normal steering. A technique for setting an area and avoiding a collision with an obstacle by steering to generate a lateral acceleration exceeding the maximum lateral acceleration when an obstacle exists in the support area is disclosed.

WO2013 / 140513 Gazette

However, the technique disclosed in Patent Document 1 described above does not disclose what kind of lateral acceleration should be generated when avoiding an emergency collision by steering. Therefore, in the technique disclosed in Patent Document 1 described above, excessive lateral acceleration may be generated when avoiding an emergency collision by steering, which may give an uncomfortable feeling to the occupant.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle driving support device capable of realizing emergency avoidance by steering against an obstacle without generating excessive lateral acceleration. do.

The vehicle driving support device according to one aspect of the present invention includes an obstacle recognizing means for recognizing an obstacle in front of the traveling path of the own vehicle, and the own vehicle based on the distance from the own vehicle to the obstacle and the own vehicle speed. The vehicle has a collision margin time calculating means for calculating the collision margin time until it collides with an obstacle, and a target lateral position for avoiding a collision with the obstacle when the collision margin time is equal to or less than a setting threshold value. The control start position is the target lateral position calculation means for calculating the position that does not deviate from the lane marking of the vehicle traveling lane in the avoidance direction, and the vehicle position when the collision margin time is equal to or less than the set threshold. Using the maximum lateral jerk allowed according to the vehicle speed, the first target path from the control start position to the intermediate position between the control start position and the target lateral position, and the target lateral position from the intermediate position. Calculates the collision avoidance time required to avoid the obstacle in the lateral direction based on the target route calculation means for calculating the second target route up to and the first target route and the second target route. Then, when the collision avoidance time is equal to or less than a threshold value set based on the collision margin time, the avoidance determination means for determining that collision avoidance with the obstacle by steering is possible, and the avoidance determination means for the obstacle. When it is determined that collision avoidance with an object is possible, the first target path and the second target path are calculated using the lateral jerk of the maximum lateral jerk or less, and the collision avoidance time is equal to or less than the threshold value. The optimum lateral jerk calculation means for calculating the minimum value of the lateral jerk as the optimum lateral jerk, and the steering control means for performing steering control for avoiding collision with the obstacle by using the optimum lateral jerk. It is prepared.

According to the vehicle driving support device of the present invention, it is possible to realize emergency avoidance by steering against an obstacle without generating excessive lateral acceleration.

According to the first embodiment of the present invention, a schematic configuration diagram of an operation support device. Same as above, flowchart showing collision avoidance steering control routine for obstacles Same as above, flowchart showing the optimal horizontal jerk calculation subroutine using the 2-minute search method. Same as above, explanatory diagram showing parameters used for collision avoidance steering control. Same as above, explanatory diagram showing parameters used for collision avoidance steering control. Same as above, an explanatory diagram showing an example of the relationship between lateral acceleration and time when collision avoidance steering control is performed using maximum lateral jerk. Same as above, an explanatory diagram showing an example of the relationship between lateral speed and time when collision avoidance steering control is performed using maximum lateral jerk. Same as above, an explanatory diagram showing an example of the relationship between the lateral position and time when collision avoidance steering control is performed using the maximum lateral jerk. Same as above, explanatory diagram showing another example of the relationship between lateral acceleration and time when collision avoidance steering control is performed using maximum lateral jerk. Same as above, explanatory diagram showing another example of the relationship between lateral speed and time when collision avoidance steering control is performed using maximum lateral jerk. Same as above, an explanatory diagram showing another example of the relationship between the lateral position and time when collision avoidance steering control is performed using the maximum lateral jerk. Same as above, an explanatory diagram showing an example of the trajectory of the own vehicle when collision avoidance steering control is performed using the maximum lateral jerk. Same as above, explanatory diagram showing an example of optimal horizontal jerk A flowchart showing a collision avoidance steering control routine for an obstacle according to a second embodiment of the present invention (No. 1). Same as above, flowchart showing collision avoidance steering control routine for obstacles (Part 2) Same as above, flowchart showing the optimal horizontal jerk selection subroutine using the 2-minute search method. Same as above, explanatory diagram showing parameters used for collision avoidance steering control. Same as above, an explanatory diagram showing an example of the trajectory of the own vehicle when collision avoidance steering control is performed using the maximum lateral jerk. A flowchart showing a collision avoidance steering control routine for an obstacle according to a third embodiment of the present invention.

Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 13. Reference numeral 1 in FIG. 1 is a driving support device for performing automatic driving, and is mounted on the own vehicle M (see FIGS. 4 and 5). The driving support device 1 includes a locator unit 11, a camera unit 21 as a driving environment acquisition unit, and an automatic driving control unit 26.

The locator unit 11 has a map locator calculation unit 12 and a high-precision road map database 16 as a storage unit.

On the input side of this map locator calculation unit 12, a GNSS (Global Navigation Satellite System) receiver 13 as a vehicle position acquisition unit, an autonomous driving sensor 14 as an operating state acquisition unit, and a route information input device. 15 is connected. The GNSS receiver 13 receives positioning signals transmitted from a plurality of positioning satellites. Further, the autonomous travel sensor 14 enables autonomous travel in an environment where the reception sensitivity from GNSS hygiene is low and the positioning signal cannot be effectively received, such as when traveling in a tunnel, and the vehicle speed sensor, yaw rate sensor, and front / rear It is composed of an acceleration sensor and the like. That is, the map locator calculation unit 12 performs localization from the movement distance and the direction based on the vehicle speed detected by the vehicle speed sensor, the yaw rate (yaw angular velocity) detected by the yaw rate sensor, the front-back acceleration detected by the front-back acceleration sensor, and the like.

The route information input device 15 is a terminal device operated by a passenger (mainly a driver). That is, the route information input device 15 aggregates a series of information required when setting a travel route in the map locator calculation unit 12, such as setting a destination or a waypoint (a service area of an expressway, etc.). You can enter it.

Specifically, the route information input device 15 is an input unit of a car navigation system (for example, a touch panel of a monitor), a mobile terminal such as a smartphone, a personal computer, or the like, and is wired to the map locator calculation unit 12. Alternatively, it is connected wirelessly.

When the passenger operates the route information input device 15 to input information on the destination and waypoints (facility name, address, telephone number, etc.), this input information is read by the map locator calculation unit 12.

When a destination or a waypoint is input, the map locator calculation unit 12 sets its position coordinates (latitude, longitude). The map locator calculation unit 12 is a vehicle position estimation calculation unit 12a as a vehicle position estimation unit that estimates the vehicle position, and a travel route setting calculation that sets a travel route from the vehicle position to the destination (and waypoint). A part 12b is provided.

Further, the high-precision road map database 16 is a large-capacity storage medium such as an HDD, and stores high-precision well-known road map information (local dynamic map). This high-precision road map information has a hierarchical structure in which additional map information necessary for supporting automatic driving is superimposed on the static information hierarchy of the lowest layer as a base. Additional map information includes road types (general roads, expressways, etc.), road shapes, left and right lane markings, exits such as expressways and bypass roads, and entrance lengths of branch lanes leading to junctions and service areas (start position). It contains static location information such as (and end location), and dynamic location information such as traffic congestion information and traffic restrictions due to accidents or construction.

The own vehicle position estimation calculation unit 12a acquires the current position coordinates (latitude, longitude) of the own vehicle M based on the positioning signal received by the GNSS receiver 13, and map-matches these position coordinates on the map information. Estimate the vehicle position (current position) on the road map. In addition, the driving lane of the own vehicle is specified, the road shape of the traveling lane stored in the map information is acquired, and the road shape is sequentially stored. Further, in an environment where the own vehicle position estimation calculation unit 12a cannot receive a valid positioning signal from the positioning satellite due to a decrease in sensitivity of the GNSS receiver 13 such as when traveling in a tunnel, the vehicle position estimation calculation unit 12a switches to autonomous navigation and autonomous traveling. Localization is performed by the sensor 14.

The travel route setting calculation unit 12b includes the position information (latitude, longitude) of the own vehicle position estimated by the own vehicle position estimation calculation unit 12a and the position information (latitude, longitude) of the input destination (and waypoint). Based on, the local dynamic map stored in the high-precision road map database 16 is referred to. Then, the travel route setting calculation unit 12b sets in advance a travel route connecting the vehicle position and the destination (if a stopover is set, the destination via the stopover) on the local dynamic map. Build according to the route conditions (recommended route, fastest route, etc.).

On the other hand, the camera unit 21 is fixed to the upper center of the front part of the vehicle interior of the own vehicle M, and includes a main camera 21a and a sub camera 21b arranged at symmetrical positions with the center in the vehicle width direction interposed therebetween. It has an in-vehicle camera (stereo camera), an image processing unit (IPU) 21c, and a forward traveling environment recognition unit 21d. The camera unit 21 captures reference image data with the main camera 21a and captures comparative image data with the sub camera 21b.

Then, both of these image data are subjected to predetermined image processing by the IPU 21c. The forward driving environment recognition unit 21d reads the reference image data and the comparison image data image-processed by the IPU 21c, recognizes the same object in both images based on the difference, and recognizes the same object in both images, and the distance data (from the own vehicle M). The distance to the object) is calculated using the principle of triangulation, and the forward driving environment information is recognized.

This forward driving environment information includes the road shape of the lane (own vehicle traveling lane) in which the own vehicle M travels (the lane marking that divides the left and right, the road curvature at the center between the lane markings [1 / m], and the distance between the left and right lane markings. Width (lane width)), exits such as highways and bypass roads, lane widths between lane markings on the branch lane side leading to junctions, intersections, crossroads, traffic lights, road signs, moving solids such as preceding vehicles and oncoming vehicles Objects and roadside obstacles O (electric poles, telegraph poles, parked vehicles, etc.) are included. In this way, the IPU21c realizes a function as an obstacle recognition means.

Further, in the automatic driving control unit 26, the front driving environment recognition unit 21d of the camera unit 21 is connected to the input side, and bidirectional communication is performed with the map locator calculation unit 12 through an in-vehicle communication line (for example, CAN: Controller Area Network). It is freely connected. Further, on the output side of the automatic driving control unit 26, a steering control unit 31 that causes the own vehicle M to travel along the travel route, a brake control unit 32 that decelerates the own vehicle M by forced braking, and a vehicle speed of the own vehicle M are controlled. The acceleration / deceleration control unit 33 and the notification device 34 such as a monitor and a speaker are connected.

In the automatic driving control unit 26, when an automatic driving section in which automatic driving control is permitted is set in the traveling route set by the traveling route setting calculation unit 12b, the target progress for performing automatic driving in the automatic driving section. Set the road. Then, in the automatic driving section, the steering control unit 31, the brake control unit 32, and the acceleration / deceleration control unit 33 are predeterminedly controlled, and the own vehicle M is based on the positioning signal indicating the own vehicle position received by the GNSS receiver 13. Is automatically driven along the target course.

At that time, the automatic driving control unit 26 detects the preceding vehicle by the well-known follow-up vehicle distance control (ACC control) and lane keeping (ALK) control based on the forward driving environment recognized by the forward driving environment recognition unit 21d. If this is the case, the vehicle follows the preceding vehicle, and if the preceding vehicle is not detected, the own vehicle M is driven at a set vehicle speed within the speed limit.

Further, as part of the ACC control, the automatic driving control unit 26 brakes to follow the preceding vehicle and stop the own vehicle M when the preceding vehicle detected in front of the traveling path of the own vehicle M stops. Take control.

Further, when the automatic driving control unit 26 detects an obstacle O having a high possibility of colliding with the own vehicle M in front of the traveling path of the own vehicle M as an interrupt control for the ACC control, the automatic operation control unit 26 is in front of the obstacle. Emergency brake (AEB (Autonomous Emergency Braking): collision damage mitigation brake) control for stopping the own vehicle M is performed.

Here, the obstacle O in the present embodiment is a three-dimensional object that may collide with the own vehicle M, and specifically, at least a part of the obstacle O in front of the traveling path of the own vehicle M is the own vehicle M. A three-dimensional object that is wrapped. The obstacle O includes not only a vehicle stopped near the shoulder of the road (see FIG. 4) but also a preceding vehicle that suddenly decelerates or stops in front of the own vehicle M.

This emergency brake control is basically performed based on the obstacle O recognized by the stereo camera, and is performed by, for example, two stages of primary brake control and secondary brake control.

The primary brake control is an alarm brake control for urging the driver to avoid a collision with an obstacle, and is a slow brake control for decelerating the own vehicle M by using a relatively small deceleration a0.

The secondary brake control is the main brake control performed when the driver does not perform an appropriate collision avoidance operation with respect to the primary brake control, and is relative to an obstacle by using a deceleration ap larger than that of the primary brake control. It is a strong brake control that decelerates the own vehicle M until the speed becomes "0".

These brake controls are executed when the relationship between the relative speed Vrel and the relative distance Dcam between the own vehicle M and the obstacle becomes equal to or less than the threshold value.

Specifically, in the present embodiment, the automatic driving control unit 26 calculates the brake control start distances D1th and D2th, which are distance thresholds, from the relationship between the relative speed Vrel and the lap rate Rap between the own vehicle M and the obstacle. .. In order to calculate these distance thresholds D1th and D2th, the automatic operation control unit 26 has a map for setting the primary brake control start distance and a map for setting the secondary brake control start distance in advance based on experiments, simulations, and the like. It is set and stored. In these maps, basically, the lower the relative speed Vrel, the smaller the distance threshold is set to delay the deceleration start timing, and the lower the lap rate R, the smaller the distance threshold is set to start deceleration. It is set to delay the timing. That is, each map is set so that the lower the relative speed Vrel and the lower the lap ratio R, the more room is left for the driver to avoid a collision with an obstacle by his / her own driving operation.

Then, when the relative distance Dcam becomes the primary brake control start distance D1th or less, the automatic operation control unit 26 performs the primary brake control through the brake control unit 32 and the acceleration / deceleration control unit 33.

Further, when an appropriate avoidance operation or the like is not performed by the driver during the primary brake control and the relative distance Dcam becomes the secondary brake control start distance D2th or less, the automatic operation control unit 26 performs the brake control unit 32 and the acceleration / deceleration control. The secondary brake control is performed through the unit 33 until the relative speed with the obstacle O becomes "0".

The collision margin time TTC (Time To Collision), which will be described later, is a parameter substantially synonymous with the relative distance Dcam in brake control. Therefore, it is also possible to use the collision margin time TTC as a parameter indicating the relationship between the relative velocity Vrel and the relative distance Dcam.

Further, during execution of the secondary brake control, the automatic driving control unit 26 calculates a collision margin time TTC (Time To Collision), which is the time until the own vehicle M collides with the obstacle O. The collision margin time TTC is, for example, a value obtained by dividing the relative distance Dcam between the own vehicle M and the front obstacle O by the relative speed Vrel between the own vehicle M and the front obstacle O ((relative distance Dcam) / (. Relative velocity Vrel))) is calculated.

When the collision margin time TTC is larger than the threshold value Tth, the automatic driving control unit 26 performs braking control through the brake control unit 32 and the acceleration / deceleration control unit 33, and stops the own vehicle M behind the obstacle O.

On the other hand, when the collision margin time TTC is equal to or less than the preset threshold value Tth, the automatic operation control unit 26 determines that it is difficult to avoid the collision with the obstacle O by the braking control, and determines that it is difficult to avoid the collision with the obstacle O, and the obstacle due to steering. In order to avoid an emergency collision with O, emergency steering (AES (Autonomous Emergency Steering)) control is performed through the steering control unit 31. Here, the threshold value Tth is a threshold value for determining whether or not there is a time margin for avoiding a collision between the own vehicle M and the obstacle O by emergency braking control in relation to the collision margin time TTC. be.

In this steering control, the automatic driving control unit 26 calculates a target lateral position for the own vehicle M to avoid a collision with the obstacle O. Further, the automatic driving control unit 26 uses the own vehicle position at the time when the collision margin time TTC becomes equal to or less than the set threshold value Tth as the control start position, and uses the maximum lateral jerk allowed according to the own vehicle speed for emergency steering control. As the target route for this purpose, a first target route from the control start position to the intermediate position between the control start position and the target lateral position and a second target route from the intermediate position to the target lateral position are calculated. Further, the automatic driving control unit 26 has a collision avoidance time required for the own vehicle M to avoid obstacles in the lateral direction based on the first target route and the second target route calculated by using the maximum lateral jerk. When t_Rap0 is calculated and the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0 (for example, Tth_Rap0 = TTC-margin α) set based on the collision margin time TTC, it is possible to avoid collision with an obstacle by steering. judge. Then, when it is determined that collision avoidance with an obstacle is possible, the automatic driving control unit 26 uses the maximum lateral jerk (maximum lateral acceleration) allowed according to the vehicle speed at the time of steering control as a reference value for 2 minutes. The optimum lateral jerk (optimal lateral jerk below the maximum lateral jerk) for lateral acceleration is set using the search method. That is, the automatic operation control unit 26 repeatedly updates the horizontal jerk J_n with the maximum horizontal jerk as the reference value a set number of times (for example, n = 10), and each time the horizontal jerk J_n is updated, it is based on the horizontal jerk J_n. When the steering control for moving the own vehicle M to the target lateral position is performed, the collision avoidance time t_Rap0 until the collision with the obstacle O can be avoided is calculated. Then, the automatic operation control unit 26 has a lateral jerk J_n (minimum lateral jerk) for realizing the maximum collision avoidance time t_Rap0 among the collision avoidance time t_Rap0 which is equal to or less than the threshold value Tth_rap0 set based on the collision margin time TTC. Is set as the optimum horizontal jerk J. When the optimum lateral jerk J is set, the automatic driving control unit 26 performs steering control through the steering control unit 31 and moves the own vehicle M to the target lateral position to avoid a collision with the obstacle O.

As described above, in the present embodiment, the automatic driving control unit 26 serves as a collision margin time calculation means, a target lateral position calculation means, a target route calculation means, an avoidance determination means, an optimum lateral jerk setting means, and a steering control means. Realize each function.

Next, the collision avoidance steering control for obstacles executed by the automatic driving control unit 26 will be described according to the flowchart of the steering avoidance control routine shown in FIG. Immediately after the collision avoidance steering control is performed, the automatic driving control unit 26 performs steering control for returning the posture of the own vehicle M to the traveling direction of the own vehicle traveling path (after t3 in FIGS. 6 to 11). Steering control) is performed, but specific description of the control will be omitted.

This routine is repeatedly executed at set time intervals. When the routine starts, the automatic driving control unit 26 first checks in step S101 whether or not the secondary brake control for the obstacle O in front of the traveling path of the own vehicle M is currently being executed.

Then, if it is determined in step S101 that the secondary brake control is not being executed, the automatic operation control unit 26 exits the routine as it is.

On the other hand, if it is determined in step S101 that the secondary brake control is being executed, the automatic operation control unit 26 proceeds to step S102, calculates the collision margin time TTC for the obstacle O, and calculates the collision margin time TTC. Checks whether or not is equal to or less than the set threshold value Tth.

Then, when it is determined that the collision margin time TTC is larger than the set threshold value Tth, the automatic driving control unit 26 exits the routine as it is in order to entrust the avoidance of collision with the obstacle O to braking control such as forced braking.

On the other hand, when it is determined that the collision margin time TTC is equal to or less than the set threshold value Tth, the automatic driving control unit 26 proceeds to step S103 and sets the target lateral position x_avoid for the own vehicle M to avoid the collision with the obstacle O. calculate.

As shown in FIGS. Assuming that the margin is x_margin, it is expressed by the following equation (1). The lateral position distance x_obj is such that when the obstacle O is to the right of the own vehicle M, the left is negative and the right is positive from the own vehicle M, and when the obstacle O is to the left of the own vehicle M. The sign is reversed.

x_avoid = ((width_own / 2) -x_obj) ＋ width_mirror ＋ x_margin… (1)
In FIGS. 4 and 5, z_diff indicates the distance from the own vehicle M to the obstacle O, and Rap indicates the amount of lap between the own vehicle M and the obstacle O.

Proceeding from step S103 to step S104, the automatic driving control unit 26 determines whether or not the own vehicle M'(see FIG. 4) when the own vehicle M is moved to the target lateral position x_avoid can exist in the avoidance space. Find out. Here, the case where the own vehicle M'can exist in the avoidance space means, for example, the case where the own vehicle M'exists in the traveling lane, that is, the case where the own vehicle M'does not extend beyond the lane marking. ..

Then, in step S104, when it is determined that the own vehicle M'after movement cannot exist in the avoidance space, the automatic driving control unit 26 exits the routine as it is.

On the other hand, if it is determined in step S104 that the own vehicle M'after movement may exist in the avoidance space, the automatic driving control unit 26 proceeds to step S105 and is necessary for collision avoidance control with the obstacle O by steering. Parameters are set.

As this parameter, the automatic operation control unit 26 has, for example, maximum lateral jerk at the time of jerk: Ja_max, maximum lateral jerk at the time of jerk: Jd_max, control standard lateral acceleration: astd_max, initial lateral velocity: vinit, initial lateral position: Set 0, lateral acceleration at the end: 0, vehicle response delay time: tdelay, and lateral position at the end (c3: see FIGS. 8 and 11): (x_avoid / 2) and the like. Here, the maximum lateral jerk Ja_max at the time of turning over and the maximum lateral jerk Jd_max at the time of turning back are the maximum lateral jerks that can be tolerated at the time of steering control, and are set variably according to the own vehicle speed. In the following description, in order to simplify the explanation, the horizontal jerk Ja at the time of additional cutting, the horizontal jerk Jd at the time of turning back, and the like are collectively referred to as the horizontal jerk J (maximum horizontal jerk is J_max).

Proceeding from step S105 to step S106, the automatic driving control unit 26 moves the own vehicle M to the target lateral position x_avoid by using the maximum lateral jerk J_max or the like (target route: first target route and Second target route) is calculated. That is, for example, the automatic operation control unit 26 substitutes various parameters such as the maximum lateral jerk J_max into a preset calculation formula for lateral acceleration, and sequentially integrates the calculation formula to obtain lateral acceleration during steering control. The transition of a (see FIGS. 6 and 9) is calculated, the transition of the lateral speed v (see FIGS. 7 and 10) is calculated, and the transition of the lateral position c indicating the traveling locus of the own vehicle M (see FIG. 12). (See FIGS. 8 and 11) is calculated. For example, as shown in FIG. 6, in this calculation, the lateral acceleration a is subjected to the upper limit processing by the control standard lateral acceleration astd.

When the vehicle proceeds from step S106 to step S107, the automatic driving control unit 26 sets the lap amount Rap between the vehicle M and the obstacle O to "0" when the vehicle M is driven along the calculated travel trajectory. The collision avoidance time t_RAP0 (see FIG. 12), which is the time until it becomes, is calculated.

When proceeding from step S107 to step S108, the automatic operation control unit 26 determines whether or not the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0 set based on the collision margin time TTC, that is, the collision avoidance time t_Rap0 is the collision margin time. It is examined whether or not it is equal to or less than the value obtained by subtracting the predetermined margin α from TTC.

Then, in step S108, when it is determined that the collision avoidance time t_Rap0 is larger than the threshold value Tth_Rap0, the automatic driving control unit 26 becomes an obstacle O even if steering control is performed based on the current lateral jerk (maximum lateral jerk J_max). Judging that it is difficult to avoid the collision, the routine is exited as it is.

On the other hand, when it is determined in step S108 that the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0, the automatic driving control unit 26 causes a collision with the obstacle O by steering control based on the current lateral jerk (maximum lateral jerk J_max). It is determined that it is possible to avoid it, and the process proceeds to step S109.

Proceeding from step S108 to step S109, the automatic operation control unit 26 calculates the optimum lateral jerk J using the two-minute search method. The calculation of the optimum horizontal jerk J is executed, for example, according to the flowchart of the optimum horizontal jerk calculation subroutine shown in FIG.

When the subroutine starts, the automatic operation control unit 26 sets the initial values of the upper limit value J_upp and the lower limit value J_low of the horizontal jerk used in the two-minute search method in step S201. Here, for example, the automatic operation control unit 26 sets the maximum horizontal jerk J_max as the initial value of the upper limit value J_upp of the horizontal jerk indicating the search range of the optimum horizontal jerk J, and sets the maximum horizontal jerk J_max as the initial value of the lower limit value J_low of the horizontal jerk in advance. Set the set value. Here, the value set as the initial value of the lower limit value J_low of the horizontal jerk can be uniformly set to "0", but for example, the self at the time when the collision margin time TTC becomes equal to or less than the set threshold value Tth. It is desirable to use a preset value (constant) for each vehicle speed.

When the process proceeds from step S201 to step S202, the automatic operation control unit 26 sets "1" as the initial value of the number of operations n by the 2-minute search method, and then proceeds to step S203.

In step S203, the automatic operation control unit 26 checks whether or not the number of operations n is less than the set number of times (for example, 10).

Then, the automatic operation control unit 26 proceeds to step S211 when it is determined in step S203 that the number of operations n is "10" or more, and when it is determined that the number of operations n is less than "10", the automatic operation control unit 26 proceeds to step S211. The process proceeds to step S204.

From step S203 to step S204, the automatic operation control unit 26 sets an intermediate value between the upper limit value J_upp of the horizontal jerk and the lower limit value J_low of the horizontal jerk as the horizontal jerk J_n for calculating the traveling locus this time.

Then, the automatic driving control unit 26 calculates the traveling locus by the lateral jerk J_n in step S205, calculates the collision avoidance time t_Rap0 in the subsequent step S206, and then proceeds to step S207. Since the processing of step S205 and step S206 is the same as the processing of step S106 and step S107 described above, the description thereof will be omitted.

In step S207, the automatic operation control unit 26 checks whether or not the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0.

Then, when it is determined in step S207 that the collision avoidance time t_Rap0 is larger than the threshold value Tth_Rap0, the automatic driving control unit 26 avoids the collision with the obstacle O even if the steering control is performed based on the current lateral jerk J_n. It is determined that this is difficult, and the process proceeds to step S208.

On the other hand, when it is determined in step S207 that the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0, the automatic driving control unit 26 can avoid the collision with the obstacle O by the steering control based on the current lateral jerk J_n. It is determined that the above is true, and the process proceeds to step S209.

From step S207 to step S208, the automatic operation control unit 26 updates the lower limit value J_low of the horizontal jerk to the current horizontal jerk J_n (J_low ← J_n) in order to narrow down the search range of the optimum horizontal jerk J, and then steps. Proceed to S210.

On the other hand, when proceeding from step S207 to step S209, the automatic operation control unit 26 updates the upper limit value J_upp of the horizontal jerk to the current horizontal jerk J_n (J_upp ← J_n) in order to narrow down the search range of the optimum horizontal jerk J. , Step S210.

When the process proceeds from step S208 or step S209 to step S210, the automatic operation control unit 26 increments the number of operations n (n ← n + 1) and then returns to step S203.

In step S203, when it is determined that the number of operations n is “10” or more and the process proceeds to step S211, the automatic operation control unit 26 has the latest Tth_Rap0 ≧ t_Rap0, that is, the latest TTC−α ≧ t_Rap0. After setting the horizontal jerk J_n of, as the optimum horizontal jerk J, exit the subroutine. Note that FIG. 13 shows an example in which the horizontal jerk J_9 used in the ninth calculation is set as the optimum horizontal jerk J.

In the main routine of FIG. 2, when proceeding from step S109 to step S110, the automatic operation control unit 26 exits the routine after performing steering control for avoiding the obstacle O by using the optimum lateral jerk J.

According to such an embodiment, the automatic driving control unit 26 uses a two-minute search method with the maximum lateral jerk (maximum lateral jerk) allowed according to the vehicle speed during steering control as a reference value, and lateral jerk J_n. Is repeatedly updated a set number of times (for example, n = 10), and every time the lateral jerk J_n is updated, a failure occurs when steering control for moving the own vehicle M to the target lateral position is performed based on the lateral jerk J_n. The collision avoidance time t_Rap0 until the collision with the object O can be avoided is calculated, and the maximum collision avoidance time t_Rap0 is realized among the collision avoidance time t_rap0 which is equal to or less than the threshold Tth_Rap0 set based on the collision margin time TTC. By setting the lateral jerk J_n (minimum lateral jerk) for the purpose as the optimum lateral jerk J, it is possible to realize emergency avoidance by steering the obstacle O without generating excessive jerk.

Next, a second embodiment of the present invention will be described with reference to FIGS. 14 to 18. Here, the first embodiment described above is based on the case where the target lateral position x_avoid that can cause the own vehicle M to exist in the lane marking line (in the avoidance space) cannot be calculated, and based on the target lateral position x_avoid and the maximum lateral jerk. When the calculated collision avoidance time t_Rap0 is larger than the threshold value Tth_Rap0, the emergency steering control is not activated. On the other hand, in the present embodiment, in the above case, a virtual target lateral position (virtual target lateral position) x_avoid'that allows the own vehicle M to exist outside the lane marking is set, and the emergency brake control is performed. Emergency steering control when there is a lateral jerk J_n in which the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0 among the lateral jerks J_n that move the own vehicle M within a range that does not deviate from the lane marking at the timing when the own vehicle M stops. It expands the area to execute. It should be noted that the description of the same configuration as that of the first embodiment described above will be omitted as appropriate.

The collision avoidance steering control for obstacles of the present embodiment executed by the automatic driving control unit 26 will be described according to the flowchart of the steering avoidance control routine shown in FIGS. 14 and 15.

This routine is repeatedly executed at set time intervals. When the routine is started, the automatic operation control unit 26 performs the same processing as in steps S101 to S110 shown in the first embodiment described above. However, if it is determined in step S104 that the own vehicle M'after movement cannot exist in the avoidance space, or if it is determined in step S108 that the collision avoidance time t_Rap0 is larger than the threshold value Tth_Rap0, the automatic driving control unit 26 proceeds to step S111 (see FIG. 15).

When the process proceeds from step S104 or step S108 to step S111, the automatic operation control unit 26 performs collision avoidance steering control in the expanded region by the following processes up to step S118. It is desirable that the collision avoidance steering control in this extended region is performed only when the obstacle O is stopped in order to ensure safety.

That is, in step S111, the automatic operation control unit 26 calculates the virtual target lateral position x_avoid'. This virtual target lateral position x_avoid'is set to a value larger than the target lateral position x_avoid, and is a virtual target lateral position that allows the own vehicle M to exist outside the lane marking. The virtual target horizontal position x_avoid'is set based on, for example, a lap amount Rap, a vehicle speed, or the like with reference to a preset map or the like.

Proceeding from step S111 to step S112, the automatic operation control unit 26 sets parameters necessary for collision avoidance control with the obstacle O by steering. Of these parameters, for example, (x_avoid'/2) is set for the horizontal position at the end (see FIG. 17).

When the process proceeds from step S112 to step S113, the automatic operation control unit 26 performs the same processing as in steps S106 and S108 described above in the processing up to step S115.

Then, when the process proceeds from step S115 to step S116, the automatic operation control unit 26 calculates the optimum lateral jerk J using the two-minute search method. The calculation of the optimum horizontal jerk J is executed, for example, according to the flowchart of the optimum horizontal jerk calculation subroutine shown in FIG.

When the subroutine starts, the automatic operation control unit 26 performs the same processing as in steps S201 to S206 shown in the first embodiment described above.

Then, when the process proceeds from step S206 to step S207, the automatic operation control unit 26 checks whether or not the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0.

Then, when it is determined in step S207 that the collision avoidance time t_Rap0 is larger than the threshold value Tth_Rap0, the automatic driving control unit 26 avoids the collision with the obstacle O even if the steering control is performed based on the current lateral jerk J_n. It is determined that this is difficult, and the process proceeds to step S220.

On the other hand, when it is determined in step S207 that the collision avoidance time t_Rap0 is equal to or less than the threshold value Tth_Rap0, the automatic driving control unit 26 can avoid the collision with the obstacle O by the steering control based on the current lateral jerk J_n. It is determined that the above is true, and the process proceeds to step S215.

From step S207 to step S215, the automatic operation control unit 26 selects the latest lateral jerk J_n in which Tth_Rap0 ≧ t_Rap0, that is, the latest horizontal jerk J_n in which TTC−α ≧ t_Rap0.

In the following step S216, the automatic driving control unit 26 calculates the time (stop time) t_stop until the own vehicle M stops by the emergency brake control.

In the following step S217, the automatic driving control unit 26 calculates the lateral position (stop lateral position) at the time when the stop time t_stop at which the own vehicle M is stopped by the emergency brake control has elapsed (see FIG. 18). That is, the automatic driving control unit 26 travels the own vehicle M along the target route (traveling locus calculated in step S205) corresponding to the selected lateral jerk Jn, and the target route at the time when the stop time t_stop elapses. The position of the own vehicle M on the above is calculated.

Then, when the process proceeds to step S218, it is checked whether or not the own vehicle M at the stop position calculated in step S217 exists in the lane marking of the own vehicle travel path.

Then, when it is determined in step S218 that the own vehicle M exists in the lane marking line, the automatic driving control unit 26 proceeds to step S219.

On the other hand, if it is determined in step S214 that the own vehicle M does not exist in the lane marking line, the automatic driving control unit 26 proceeds to step S220.

From step S218 to step S219, the automatic operation control unit 26 updates the upper limit value J_upp of the horizontal jerk to the current horizontal jerk J_n (J_upp ← J_n) in order to narrow down the search range of the optimum horizontal jerk J, and then steps. Proceed to S221.

Then, in step S221, the automatic driving control unit 26 proceeds to step S222 after determining that there is a lateral jerk that can be controlled by the expanded collision avoidance steering control.

Further, when proceeding from step S201 or step S218 to step S220, the automatic operation control unit 26 updates the lower limit value J_low of the horizontal jerk to the current horizontal jerk J_n in order to narrow down the search range of the optimum horizontal jerk J (J_low ← J_n). ), Then the process proceeds to step S222.

When the process proceeds from step S220 or step S221 to step S222, the automatic operation control unit 26 increments the number of operations n (n ← n + 1) and then returns to step S203.

In step S203, when it is determined that the number of operations n is "10" or more and the process proceeds to step S223, the automatic operation control unit 26 checks whether or not it is determined that there is a controllable lateral jerk in step S221 described above. ..

Then, if it is not determined in step S221 that there is a controllable lateral jerk, the automatic operation control unit 26 exits the subroutine as it is from step S223.

On the other hand, when it is determined in step S221 that there is a controllable lateral jerk, the automatic operation control unit 26 proceeds from step S223 to step S224, and optimally determines the smallest lateral jerk J_n among the controllable lateral jerks. After setting as jerk J, exit the subroutine.

In the main routine of FIG. 15, when proceeding from step S116 to step S117, the automatic operation control unit 26 checks whether or not the optimum jerk J is set in step S116.

Then, when it is determined in step S117 that the optimum jerk J is not set, the automatic operation control unit 26 exits the routine as it is.

On the other hand, if it is determined in step S118 that the optimum jerk J has been set, the automatic operation control unit 26 proceeds to step S118, and after performing steering control for avoiding the obstacle O using the optimum lateral jerk J. , Exit the routine.

According to such an embodiment, in addition to the action and effect shown in the first embodiment described above, the action and effect that the room for avoiding the collision with the obstacle O can be expanded by the emergency steering control can be obtained.

Next, a third embodiment of the present invention will be described with reference to FIG. Here, in the second embodiment described above, when it is difficult to avoid steering with an obstacle based on the target lateral position, steering avoidance with the obstacle based on the virtual target lateral position is performed. On the other hand, the present embodiment is mainly different in that it is possible to avoid steering with an obstacle based on the target lateral position in advance and whether it is possible to avoid steering with an obstacle based on the virtual target lateral position. The same configurations as those of the first and second embodiments described above will be omitted as appropriate.

The collision avoidance steering control for an obstacle of the present embodiment executed by the automatic driving control unit 26 will be described according to the flowchart of the steering avoidance control routine shown in FIG.

This routine is repeatedly executed at set time intervals. When the routine starts, the automatic driving control unit 26 first checks in step S301 whether or not the secondary brake control for the obstacle O in front of the traveling path of the own vehicle M is currently being executed.

Then, if it is determined in step S301 that the secondary brake control is not being executed, the automatic operation control unit 26 exits the routine as it is.

On the other hand, if it is determined in step S301 that the secondary brake control is being executed, the automatic operation control unit 26 proceeds to step S302, calculates the collision margin time TTC for the obstacle O, and calculates the collision margin time TTC. Checks whether or not is equal to or less than the set threshold value Tth.

Then, when it is determined that the collision margin time TTC is larger than the set threshold value Tth, the automatic driving control unit 26 exits the routine as it is in order to entrust the avoidance of collision with the obstacle O to braking control such as forced braking.

On the other hand, when it is determined that the collision margin time TTC is equal to or less than the set threshold value Tth, the automatic operation control unit 26 proceeds to step S303, and whether or not it is possible to avoid the collision with the obstacle O by using the target lateral position x_avoid. Find out.

Here, in the present embodiment, the automatic operation control unit 26 is provided with a map or the like for determining in advance whether or not collision with the obstacle O is possible based on the target lateral position x_avoid. It is set based on simulation etc. By using this map or the like, the automatic operation control unit 26 determines whether or not collision avoidance with the obstacle O is possible based on the target lateral position x_avoid based on the lap rate Rap with the obstacle O and the relative speed Vrel and the like. It is possible to do.

Then, when it is determined in step S303 that collision avoidance with the obstacle O based on the target lateral position x_avoid is possible, the automatic driving control unit 26 proceeds to step S305 and collision avoidance steering control based on the target lateral position x_avoid. After doing, exit the routine.

That is, when proceeding from step S303 to step S305, the automatic operation control unit 26 exits the routine after performing the processes of steps S103 to S110 of FIG. 2 shown in the first embodiment described above.

On the other hand, if it is determined in step S303 that it is difficult to avoid a collision with the obstacle O based on the target lateral position x_avoid, the automatic operation control unit 26 proceeds to step S304 and uses the virtual target lateral position x_avoid'to make an obstacle. Check whether it is possible to avoid a collision with an object O.

Here, in the present embodiment, the automatic operation control unit 26 is provided with a map or the like for determining in advance whether or not collision with the obstacle O is possible based on the virtual target lateral position x_avoid'. It is set based on experiments and simulations. By using this map or the like, the automatic operation control unit 26 can avoid the collision with the obstacle O based on the virtual target lateral position x_avoid'based on the lap rate Rap with the obstacle O and the relative speed Vrel and the like. It is possible to make a judgment.

Then, in step S304, when it is determined that it is difficult to avoid the collision with the obstacle O based on the virtual target lateral position x_avoid', the automatic operation control unit 26 exits the routine as it is.

On the other hand, if it is determined in step S304 that collision avoidance with the obstacle O based on the virtual target horizontal position x_avoid'is possible, the automatic operation control unit 26 proceeds to step S306 and is based on the virtual target horizontal position x_avoid'. After performing collision avoidance steering control, exit the routine.

That is, when proceeding from step S304 to step S306, the automatic operation control unit 26 exits the routine after performing the processes of steps S111 to S118 of FIG. 15 shown in the second embodiment described above.

According to such an embodiment, it is possible to obtain the same effect as that of the second embodiment described above.

Here, in each of the above-described embodiments, the map locator calculation unit 12, the forward traveling environment recognition unit 21d described later, the automatic operation control unit 26, the steering control unit 31, the brake control unit 32, and the acceleration / deceleration control unit 33 are It is composed of a well-known microcomputer equipped with a CPU, RAM, ROM, a non-volatile storage unit, etc., and its peripheral devices, and the ROM stores in advance fixed data such as programs and data tables executed by the CPU. .. All or part of the functions of the processor may be configured by a logic circuit or an analog circuit, or the processing of various programs may be realized by an electronic circuit such as FPGA.

The inventions described in the above embodiments are not limited to those embodiments, and various modifications can be carried out at the implementation stage without departing from the gist thereof. Further, each of the above forms includes inventions at various stages, and various inventions can be extracted by an appropriate combination of the plurality of disclosed constituent requirements.

For example, even if some constituents are deleted from all the constituents shown in each form, if the described problem can be solved and the stated effect is obtained, this constituent is deleted. The configuration can be extracted as an invention.

1 ... Driving support device 11 ... Locator unit 12 ... Map locator calculation unit 12a ... Own vehicle position estimation calculation unit 12b ... Driving route setting calculation unit 13 ... GNSS receiver 14 ... Autonomous driving sensor 15 ... Route information input device 16 ... High accuracy Road map database 21 ... Camera unit 21a ... Main camera 21b ... Sub camera 21d ... Forward driving environment recognition unit 26 ... Automatic driving control unit 31 ... Steering control unit 32 ... Brake control unit 33 ... Acceleration / deceleration control unit 34 ... Notification device M ... Own vehicle O ... Obstacles

Claims (4)

Obstacle recognition means for recognizing obstacles in front of the vehicle's driving path,
A collision margin time calculating means for calculating the collision margin time until the own vehicle collides with the obstacle based on the distance from the own vehicle to the obstacle and the own vehicle speed.
When the collision margin time is equal to or less than the set threshold value, the target lateral position for avoiding a collision with the obstacle is calculated at a position where the own vehicle does not deviate from the lane marking of the own vehicle traveling lane in the avoidance direction. Position calculation means and
The control start position is the position of the own vehicle when the collision margin time becomes equal to or less than the set threshold value, and the control start position and the control start position are used from the control start position using the maximum lateral jerk allowed according to the own vehicle speed. A target route calculation means for calculating a first target route to an intermediate position with the target lateral position and a second target route from the intermediate position to the target lateral position.
The collision avoidance time required to avoid the obstacle in the lateral direction is calculated based on the first target path and the second target path, and the collision avoidance time is set based on the collision margin time. When the value is equal to or less than the threshold value, the avoidance determination means for determining that the collision with the obstacle can be avoided by steering, and the avoidance determination means.
When it is determined by the avoidance determination means that collision avoidance with the obstacle is possible, the first target route and the second target route are calculated using the lateral jerk equal to or less than the maximum lateral jerk, and the said. Optimal lateral jerk calculation means for calculating the minimum value of the lateral jerk whose collision avoidance time is equal to or less than the threshold value as the optimum lateral jerk.
A vehicle driving support device comprising: a steering control means for performing steering control for avoiding a collision with the obstacle by using the optimum lateral jerk. The optimum lateral jerk setting means sets the maximum lateral jerk as the initial value of the upper limit of the search range of the optimum lateral jerk when the collision avoidance time calculated based on the maximum lateral jerk is equal to or less than the threshold value. At the same time, the preset value is set as the initial value of the lower limit value of the search range of the optimum horizontal jerk, and the collision avoidance time calculated based on the horizontal jerk of the intermediate value between the upper limit value and the lower limit value is set. When the value is equal to or less than the threshold value, the upper limit value is updated by the intermediate value, and when the collision avoidance time calculated based on the intermediate value is larger than the threshold value, the lower limit value is updated by the intermediate value. The vehicle driving support device according to claim 1. Claim 1 or claim 2 is characterized in that the collision margin time calculating means calculates the collision margin time when the emergency brake control in which the relative speed between the own vehicle and the obstacle is "0" is executed. The vehicle driving support device described in. The target lateral position calculation means cannot calculate the target lateral position at a position that does not deviate from the division line of the own vehicle traveling lane, or the first target lateral position is calculated based on the target lateral position and the maximum jerk. When the collision avoidance time based on the target route and the second target route is at least one of the times larger than the threshold value, the virtual target lateral position is calculated at the position where the own vehicle deviates from the lane marking. death,
The target route calculation means calculates the first target route and the second target route based on the control start position and the virtual target lateral position.
The optimum lateral jerk calculation means has the collision avoidance time equal to or less than the threshold value among the lateral jerks that move the own vehicle within a range that does not deviate from the division line at the timing when the own vehicle stops by the emergency brake control. The vehicle driving support device according to claim 3, wherein the minimum value of the lateral jerk is calculated as the optimum lateral jerk.

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