JP2006190237A - Direction change supporting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a direction change supporting system for supporting a direction change of a vehicle during U-turn or K-turn. <P>SOLUTION: The direction change supporting system comprises a navigation system 11, a rotation radius information storage means 14 for recording rotation radius information for the rotation radius of an owned vehicle, a U-turn propriety determining means 15 for determining whether U-turn is possible or not in accordance with road width information for a road on which the owned vehicle travels, acquired from the navigation system, and the rotation radius information, and direction change supporting means 20, 100 for supporting the direction change of the owned vehicle in accordance with the determination result of the U-turn propriety determining means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a direction change support system that supports a vehicle operation for turning a vehicle to make a U-turn or turning and turning the vehicle.

When driving a vehicle, there may be a situation where a U-turn of the vehicle is necessary, for example, when the user wants to return to the original location by mistake or to stop at a store in the opposite lane. For this reason, a navigation device that searches for a U-turn area where a U-turn is possible and guides the vehicle through the U-turn area has been proposed (see, for example, Patent Document 1). In the navigation device described in Patent Document 1, if the route is incorrect, the driver is provided with a route from the U-turnable area to the destination and a route from the place where the route is erroneously traveled to the destination. Therefore, the driver can select a desired route based on the arrival time and the like.
JP 2002-340585 A

  However, the navigation device described in Patent Document 1 does not describe an operation for making a U-turn of the vehicle, only presenting an area where U-turn is possible. Since there is an area where the U-turn is prohibited in the U-turn of the vehicle, the driver must first determine whether or not the area allows the U-turn. In addition, when making a U-turn, in addition to the traffic regulation, it is necessary to grasp the traveling state of the vehicle in the opposite lane. Even if the U-turn reaches a point where it is not regulated, it is necessary to control the steering angle and the vehicle speed appropriately according to the road width and the turning radius of the vehicle. Appropriate vehicle operation is required. That is, when making a U-turn, the driver is required to check whether the area is a U-turn prohibited area, grasp the situation near the area where the U-turn is possible, and perform appropriate vehicle operation. However, a direction change support system that supports the driver's U-turn operation has not been proposed so far.

  In view of the above problems, an object of the present invention is to provide a direction change support system that supports a direction change of a vehicle by a U-turn or a turnback.

  In order to solve the above-described problems, the present invention provides a navigation system, a rotation radius information storage unit in which rotation radius information related to the rotation radius of the host vehicle is recorded, and road width information of a road on which the host vehicle travels obtained from the navigation system. And a U-turn availability determination unit that determines whether or not a U-turn is possible based on the turning radius information, and a direction change support unit that supports the direction change of the host vehicle based on the determination result of the U-turn availability determination unit. The present invention provides a direction change support system characterized by comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the direction change assistance system which assists the direction change of the vehicle by a U turn or a turnback can be provided. In addition, the direction change can be supported regardless of the driving skill of the driver. The road on which the host vehicle is traveling is not limited to a road and includes a traveling location.

  Further, in one embodiment of the direction change support system of the present invention, when the U-turn availability determination means determines that the U-turn is impossible, the turning trajectory estimation means estimates the return trajectory for turning the own vehicle and changing the direction. (Corresponding to the traveling trajectory estimating means 18 in FIG. 1) and a turning travel control means for causing the host vehicle to travel on the turn trajectory estimated by the turning trajectory estimating means.

  According to the present invention, even if the direction cannot be changed by the U-turn, the direction can be changed by turning back.

  Further, in one embodiment of the direction change support system of the present invention, when the U turn enable / disable determination unit determines that a U turn is possible, the direction change support unit causes the U-turn to travel the vehicle at a predetermined rudder angle. It has a traveling control means.

  ADVANTAGE OF THE INVENTION According to this invention, the direction change by a U-turn can be supported irrespective of a driver | operator's driving proficiency.

  Moreover, in one form of the direction change assistance system of this invention, a direction change assistance means teaches the driver | operator the steering amount for a direction change, It is characterized by the above-mentioned.

  According to the present invention, the driver can perform steering for changing the direction with reference to the taught steering amount.

  Moreover, in one form of the direction change assistance system of this invention, it has the estimated locus estimation means which estimates the estimated locus | trajectory of the own vehicle based on the steering angle detected from the steering angle sensor, The driver is instructed of the expected trajectory estimated by the estimating means, and the U-turn traveling trajectory or the turning trajectory estimated by the turning trajectory estimating means when traveling at a predetermined steering angle.

  According to the present invention, since the predicted trajectory of the host vehicle and the trajectory to be targeted are taught, the driver can steer the predicted trajectory closer to the trajectory to be targeted.

  Moreover, in one form of the direction change assistance system of this invention, the determination result of the availability of the U-turn by the U-turn availability determination means is notified to the driver.

  According to the present invention, since the determination result of whether or not the U-turn is possible is notified to the driver, the driver can determine whether or not to turn back. The notification to the driver is made by displaying on the navigation screen, the windshield, and by voice.

  Further, the present invention is based on a navigation system, traveling lane detecting means for detecting the traveling lane of the own vehicle, traveling lane of the own vehicle detected by the traveling lane detecting means, and U-turn regulation information acquired from the navigation system. And an area determination means for determining whether or not the host vehicle exists in an area where U-turn is possible.

  According to the present invention, it is possible to automatically detect whether or not the traveling lane is at the right end and determine whether or not the U-turn is restricted. Therefore, in the information from the navigation system, even if a U-turn is possible, since the U-turn is not performed when driving on the left lane or at a U-turn prohibited point, dangerous driving support is not performed.

  Further, in one aspect of the direction change support system of the present invention, the traveling lane detecting means detects the traveling lane from at least one of the coordinate data of the own vehicle acquired from the navigation system or the vehicle operation of the own vehicle. To do.

  According to the present invention, since the traveling lane can be detected from either or both of the navigation system and the vehicle operation, the traveling lane can be detected with higher accuracy.

  Moreover, in one form of the direction change assistance system of this invention, the vehicle operation of the own vehicle is operation of a direction indicator or a steering angle, It is characterized by the above-mentioned.

  According to the present invention, when the rudder angle is large, it can be determined to turn left and right, and when the rudder angle is small, it can be determined that the lane is changed.

  The direction change support system according to the present invention further includes an image capturing unit that captures an image in front of the vehicle, and the traveling lane detecting unit is configured to automatically detect the travel lane based on the white line detected from the image captured by the image capturing unit. Detecting the travel lane of the vehicle.

  According to the present invention, the traveling lane of a vehicle can be detected more accurately based on a white line detected from a captured image.

  It is possible to provide a direction change support system that supports a direction change of a vehicle by a U-turn or turn-back.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a functional block diagram of the direction change support system of the present embodiment. According to the direction change support system of the present embodiment, it is possible to change the direction of the vehicle by supporting the U-turn or the turn-back operation of the host vehicle regardless of the driving skill of the driver. In addition, the direction change in a present Example means changing the advancing direction of a vehicle into an opposite lane.
The direction change support system of FIG. 1 includes a traveling lane detection means 13, a U-turn availability determination means 15, an area determination means 16, a direction change support means 20, an image processing device 12, and a rotation radius of the vehicle. And a turning radius information storage means 14 in which the radius information is stored.

  The direction change support means 20 is electrically connected to the engine ECU 25, the brake ECU 26, and the active steering 27, and the vehicle can be automatically controlled via these. Further, the direction change support means 20 is configured to have a U-turn travel control means 17 and a turning travel control means 19. The U-turn travel control means 17 changes the direction of the vehicle by the U-turn, and the turning travel control means 19. Controls traveling of the vehicle so as to change the direction of the vehicle by turning back. The direction change support system operates in conjunction with the navigation system 11.

  The traveling lane detection means 13 detects the lane in which the host vehicle is traveling. The traveling lane detector 13 detects the number of lanes on which the host vehicle is traveling, and detects which lane the host vehicle is traveling on when there are a plurality of lanes. For example, when a lane of three lanes is detected on one side, it is detected whether the lane in which the host vehicle travels is the right side, the center, or the left side.

  The travel lane detection means 13 is linked to the navigation system 11. The navigation system 11 estimates the position of the vehicle based on the arrival time of the radio wave received from the GPS (Global Positioning System) and the satellite orbit. When the position of the vehicle is estimated, the traveling lane of the own vehicle can be detected from the traveling position of the own vehicle with respect to the width of the road. A vehicle speed pulse is input from the vehicle speed sensor 24 to the navigation system 11, and the vehicle position of the road map data is estimated with high accuracy by map matching based on the vehicle speed pulse, the traveling direction, and the road map data. Map matching is performed by comparing the travel direction by the direction sensor attached to the vehicle and the travel distance by the vehicle speed pulse with the coordinate data obtained by the GPS. When the deviation from the coordinate data becomes large, the accurate vehicle position is maintained by correcting the traveling position on the road map. When map matching is performed normally, 1 is set in Map_flag indicating whether map matching is possible, and Map_flag is set to 0 in places where map matching cannot be performed such as tunnels and building shadows where reception of radio waves from GPS is difficult. Is set. Therefore, when Map_flag is 1, the traveling lane detection unit 13 can detect the traveling lane from the navigation system 11.

  Further, the navigation system 11 includes information on the number of lanes of the road in the road map data, receives coordinate data of the host vehicle by GPS or the like, and uses the road map data to obtain information on the number of lanes of the road on which the host vehicle runs. Can be acquired. Further, the navigation system 11 has information on traffic regulation such as U-turn prohibition regarding the roads recorded in the road map data.

  In addition, a CCD camera 21 is mounted on the host vehicle as an image capturing unit that captures an image outside the vehicle. The image captured by the CCD camera 21 is processed by the image processing device 12 and then sent to the traveling lane detecting means 13. The CCD camera 21 is installed, for example, in the vicinity of a room mirror in the vehicle interior and captures a predetermined range in front of the vehicle. Note that any solid-state imaging device such as a CMOS device may be used for a camera that captures the front of the vehicle.

  The image processing device 12 extracts the outline of the white line from the road image data captured by the CCD camera 21. The outline of the white line is detected from the bottom of the image upward, for example, based on the luminance of the image. If it is a white line, a rectangular region appears continuously or at a predetermined interval from the bottom of the image to the top, and if a rectangular shape equal to or greater than the predetermined threshold is detected, it is detected as a white line. The white line detection rate LineP is calculated from the proportion of the white line actually detected for the assumed rectangular area, and when the line P has a detection rate equal to or higher than a predetermined level, the white line is detected to the extent that the traveling lane can be determined. It is determined that

  The traveling lane detecting means 13 detects the number of lanes from the image processed by the image processing device 12 and also the lane in which the host vehicle is traveling depending on the position (right or left) of the white line with respect to the host vehicle. Is detected. The detection of the travel lane by the image processing device 12 is effective when the navigation system 11 cannot be linked, and the accuracy of the detection of the travel lane is improved by using it together with the navigation system 11. The traveling lane detection means 13 is not limited to the lane, and when the CCD camera 21 captures that a vehicle having the same traveling direction as the own vehicle exists on the right (or left), the traveling lane of the own vehicle is left ( Or right).

  The traveling lane detection means 13 is connected to the direction indicator 22 and the steering angle sensor 23. From the direction indicator 22, there is a vehicle operation for turning right or left or changing lanes to the left and right, and the magnitude of the rudder angle STR detected by the rudder angle sensor 23 is input to the traveling lane detection means 13. The operation result of the direction indicator 22 is input to the traveling lane detecting means 13 as a flag LR_flag indicating a direction (in the case of 0, there is no operation of the direction indicator 22).

  The traveling lane detection means 13 can detect whether the lane has been changed, turned right or left based on the size of the steering angle of the steering angle sensor 23, and can detect the traveling lane of the host vehicle. The detection of the travel lane by the direction indicator 22 and the rudder angle sensor 23 is effective when the navigation system 11 cannot be linked, and it is used together with the detection of the travel lane by the navigation system 11 and the image processing device 12. Detection accuracy is improved.

  The area determination means 16 receives the travel lane of the host vehicle detected by the travel lane detection means 13 and information related to traffic regulation such as U-turn regulation information from the navigation system 11. The area determination means 16 determines whether or not the host vehicle is present in a U-turnable area based on whether or not the vehicle is traveling in the rightmost lane and whether or not the U-turn is restricted. Further, an area where the U-turn is not restricted can be acquired from the navigation system 11 from the front in the traveling direction of the vehicle.

The determination result as to whether or not the vehicle is in an area where the U-turn is possible is input from the area determination unit 16 to the U-turn availability determination unit 15. Further, the U-turn availability determination unit 15 is connected to a turning radius information storage unit 14 in which turning radius information such as the turning radius of the vehicle is stored, and acquires the minimum turning radius of the host vehicle from the turning radius information storage unit 14. To do. The U-turn availability determination means 15 determines whether or not the direction change by the U-turn is possible based on the minimum turning radius and the road width.
Further, the U-turn availability determination unit 15 is configured to include a traveling trajectory estimation unit 18. The traveling track estimation means 18 estimates the traveling track of the host vehicle when the direction change by the U-turn or the direction change by turn-back is performed based on the minimum turning radius and the information on the road width. In addition, the estimation of the traveling track by the U-turn or the turn-back will be described later.

  The U-turn availability determination means 15 sends the U-turn travel control means 17 with the steering angle for making a U-turn or the traveling track of the host vehicle when the direction is changed by the U-turn. The U-turn travel control means 17 controls the vehicle according to the sent steering angle for making a U-turn, or the travel trajectory of the U-turn as a target travel trajectory.

  Further, the U-turn availability determination unit 15 sends a traveling track estimated when the direction is changed by turning back to the turning traveling control unit 19. The turning traveling control means 19 performs traveling control of the vehicle with the traveling trajectory by the sent back as a target traveling trajectory.

  The U-turn travel control means 17 and the turning travel control means 19 are connected to an engine ECU 25, a brake ECU 26, and an active steering 27 that can perform a forced steering operation. The U-turn travel control means 17 and the turning travel control means 19 adjust the opening of the engine throttle and perform a steering operation, and also control the vehicle speed by braking the vehicle, thereby turning the vehicle in a U-turn or turning direction. Can be converted.

  Based on the above configuration, the control procedure of the direction change support system will be described with reference to the flowcharts of FIGS. In the present embodiment, the description will be divided into the determination of the traveling lane of the host vehicle in FIG. 2, the determination of whether or not the U-turn is possible, and the estimation of the turning trajectory in FIG.

[Determination of the driving lane of the vehicle]
The process in the flowchart of FIG. 2 operates when, for example, the driver instructs the U-turn of the vehicle or returns from the travel route to the destination to return to the original travel route.

  The traveling lane detection means 13 periodically acquires estimation information of the traveling position of the vehicle from the GPS and the navigation system 11 (S10). When Map_flag of the navigation system 11 is 1 (Yes in Step S11), the traveling lane detecting means 13 determines that the traveling lane in the navigation system 11 is the current traveling lane, assuming that the traveling position of the vehicle is accurately detected. (S20).

  When Map_flag of the navigation system 11 is 0 (No in step S11), the number of lanes of the road that is running is acquired from the navigation system 11 (S12). If the number of lanes on one side is 1, the current travel lane is at the right end and a U-turn can be made from the travel lane.

  When there are a plurality of lanes on the traveling road, the image processing device 12 detects a white line from the road image data captured by the CCD camera 21. As a result of detecting the white line, if the white line detection rate LineP is equal to or higher than a predetermined value (for example, 70% or higher) (Yes in step S13), the traveling lane detecting unit 13 determines that the white line is detected and travels. A lane is determined (S20).

  The traveling lane detecting means 13 may detect the traveling lane based on the image data of the traveling vehicle photographed by the CCD camera 21. For example, when a vehicle having the same traveling direction exists on the right side, it can be determined that the traveling lane of the host vehicle is not at least the right end.

  When the white line detection rate LineP is lower than the predetermined value (No in step S13), the traveling lane detection means 13 detects the operation of the direction indicator from the direction indicator 22, and also detects the steering operation from the rudder angle sensor 23 (S14). ) And determine the driving lane.

... Driving lane determination by operation of steering angle STR and direction indicator (S15) ...
Next, the traveling lane detector 13 detects the traveling lane of the host vehicle by determining whether the vehicle is turning right or left or changing lanes. FIGS. 4A and 4B show a travel line determined by the steering angle detected by the steering angle sensor 23. FIG. 4A shows a travel line when turning right, and FIG. 4B shows a travel line when changing lanes to the right lane.

  FIG. 5 shows an example of determination logic for determining whether to turn left or right or change lanes. When LR_flag is 0 (Yes in step S151), the traveling lane detecting means 13 determines that the most recent traveling lane with Map_flag of 1 is the current traveling lane because there is no lane change or left / right turn (S157). .

  When LR_flag is other than 0 (No in Step S151), the traveling lane detection means 13 determines whether or not the steering angle STR is equal to or greater than a predetermined value S (S> 0) (S152). For example, when the steering angle STR is 40 degrees or more (Yes in step S152), the traveling lane detection means 13 determines that the vehicle has turned right or left (determines that there is no lane change), and the latest Map_flag is 1. The travel lane in the state is determined as the current travel lane (S157).

  When the steering angle STR is smaller than the predetermined value S (No in Step S152), the traveling lane detection means 13 determines whether or not the steering angle STR is 0 or more (S154). Since the steering angle STR is positive when the steering operation is clockwise, if the steering angle STR is 0 or more (Yes in step S154), it is determined that the lane has been changed to the right lane (S155), and the traveling lane is detected. The means 13 determines that the right lane is the travel lane from the travel lane in which the latest Map_flag is 1 (S155).

  If the rudder angle STR is smaller than 0 (No in step S154), it is determined that the lane has been changed to the left lane (S156), and the traveling lane detection means 13 starts from the traveling lane in which the latest Map_flag is 1. The left lane is determined as a travel lane (S156). Therefore, the traveling lane detecting means 13 can determine the traveling line as shown in FIG. 4A or 4B by the determination logic of FIG. 5 and determine the lane in which the host vehicle is traveling.

  Further, when a steering operation is performed to avoid an obstacle (for example, when there is an obstacle detection result by a millimeter wave radar), the traveling lane can be determined except for a steering operation to avoid the obstacle.

  If the lane change has been performed a plurality of times, the determination of FIG. 5 is performed a plurality of times. In such a case, the original travel lane as a reference is not a travel lane in which the latest Map_flag is 1, but a travel lane determined as a travel lane by the process.

  Thus, the determination logic of FIG. 5 is completed, the process returns to FIG. 2, and the travel lane of the host vehicle is determined (S20).

[Judgment of U-turn availability and estimation of turning trajectory]
Next, the procedure for determining whether or not the U-turn is possible and estimating the return trajectory in FIG. 3 will be described. First, the travel lane detected by the travel lane detection means 13 and the presence / absence of the U-turn restriction acquired from the navigation system 11 are acquired (S21).

  The area determination means 16 acquires vehicle information from surrounding vehicles so as not to obstruct traffic of surrounding vehicles, particularly vehicles in the opposite lane (S22). From the vehicle information of the surrounding vehicles, it is possible to obtain information on the traffic volume in the opposite lane and information on the surrounding vehicles such that the vehicle information cannot be obtained because the vehicle cannot communicate with the vehicle in the opposite lane. In addition, reception or transmission of vehicle information from surrounding vehicles is performed via vehicle-to-vehicle communication or infrastructure mounted on road devices such as guardrails and traffic lights.

  The area determination means 16 determines whether or not the U-turn is permitted based on the traveling lane of the host vehicle, the U-turn regulation information and the vehicle information of the surrounding vehicles (S23). Note that the driver may determine whether or not the U-turn driving is possible based on the situation of surrounding vehicles.

  If the U-turn is not permitted (No in step S23), the driver is informed of the conditions for limiting the U-turn among the traveling lane of the host vehicle, the U-turn regulation information, or the vehicle information of the surrounding vehicles. Wait until it is permitted, or guide to an area where U-turn is possible.

  Next, the U-turn availability determination means 15 determines whether or not a U-turn travel is possible based on the relationship between the minimum turning radius RM and the road width D (S24). The U-turn availability determination unit 15 obtains the minimum turning radius from the turning radius information storage unit 14 and obtains the road width of the running road from the navigation system 11.

  FIG. 6A is a diagram showing the relationship between the road width D and the minimum turning radius RM of the host vehicle. The center M1 of the host vehicle faces the direction X, and turns to the direction Y by the U-turn. When the road width D is larger than twice the minimum turning radius RM (D> 2 × RM), the host vehicle can make a U-turn without interfering with the left side of the opposite lane. Actually, since the host vehicle has a predetermined vehicle width, it is preferable to secure a margin for the vehicle width α such that D> 2 × RM + α.

  When the road width D is larger than twice the minimum turning radius RM (Yes in step S25), the host vehicle performs a U-turn operation on the surrounding vehicles or performs a surrounding operation by inter-vehicle communication or the like. The vehicle is notified (S26).

  Further, the U-turn availability determination means 15 outputs to the U-turn travel control means 17 that a U-turn is possible. The U-turn travel control means 17 sends a signal to the actuator of the active steering and also signals the engine ECU 25 and the brake ECU 26 to travel at a predetermined speed in order to travel the vehicle with the minimum turning radius RM based on a predetermined steering angle. Is sent out. As a result, the vehicle changes direction by a U-turn as shown in FIG. 6B (S30). The travel trajectory estimation unit 18 may estimate the U-turn travel trajectory and send it to the U-turn travel control unit 17. The U-turn travel control means 17 can control the vehicle for the estimated travel path of the U-turn.

  Before starting the U-turn travel by the U-turn travel control means 17, the driver may be prompted to input whether to start the U-turn travel.

... Change of direction by turning back (S27-S29) ...
When the road width D is not larger than twice the minimum turning radius RM (No in step S24), the traveling trajectory estimation means 18 estimates a traveling trajectory for turning around by turning back (S27). The direction change support system notifies the driver that the direction cannot be changed by the U-turn. As a result, the driver can stop the process when the U-turn may be used but the driver does not want to switch back.

  FIG. 7 is a diagram for explaining the direction change by turning back. The vehicle center of the host vehicle is assumed to be at a position M1 in FIG. 7A, and the direction is changed by turning back from the position M1.

  The estimation of the traveling track will be described. It is known that there is a relationship of the formula (1) between the turning radius and the steering angle STR. Therefore, the steering angle STR for traveling at the minimum turning radius RM of the vehicle is obtained by the equation (2).

図７（ａ）に示すように、最小回転半径ＲＭとなるように舵角を制御しても道路幅Ｄが最小回転半径ＲＭの２倍以下となるので（Ｄ≦２×ＲＭ）、自車両は反対車線の左側と干渉する。かかる場合には、走行軌道推定手段１８は、図７（ｂ）に示すように切り返して走行する軌道を推定する。図７（ｂ）の切り返し操作では、前進走行による一次旋回Ｌ１、後退走行による二次旋回Ｌ２、及び、最終的に反対車線の走行を開始する三次旋回Ｌ３が示されている。本実施例では、一次旋回Ｌ１及び二次旋回Ｌ２を切り返しによる方向転換の旋回軌道と称す。

As shown in FIG. 7 (a), even if the rudder angle is controlled to be the minimum turning radius RM, the road width D is not more than twice the minimum turning radius RM (D ≦ 2 × RM). Interferes with the left side of the opposite lane. In such a case, the traveling trajectory estimation means 18 estimates the trajectory to travel by turning back as shown in FIG. In the turn-back operation of FIG. 7B, a primary turn L1 by forward travel, a secondary turn L2 by reverse travel, and a tertiary turn L3 that finally starts traveling in the opposite lane are shown. In the present embodiment, the primary turn L1 and the secondary turn L2 are referred to as turning trajectories for changing direction by turning back.

  The traveling trajectory estimating means 18 calculates the traveling rotational angle θ of the vehicle with respect to the rotational center C when the vehicle travels with the rudder angle STR having the minimum rotational radius RM, using the equation (3). As shown in Expression (3), the traveling rotation angle θ is calculated by an inverse cosine function based on the road width D and the minimum rotation radius RM.

走行回転角度θが求められると一次旋回Ｌ１の旋回距離は、式（４）により算出される。
一次旋回Ｌ１の走行が終了した時点では、自車両は、反対車線に対し角度φをなして、反対車線の左側の位置Ｍ２にあると推定される。なお、φは反対方向に方向転換するための回転角度１８０度から一次旋回Ｌ１の走行回転角度θを減じたものである。したがって、φとθの間にはφ＝１８０−θの関係がある。

When the traveling rotation angle θ is obtained, the turning distance of the primary turning L1 is calculated by the equation (4).
When the travel of the primary turn L1 is completed, the host vehicle is estimated to be at a position M2 on the left side of the opposite lane at an angle φ with respect to the opposite lane. Here, φ is obtained by subtracting the traveling rotation angle θ of the primary turn L1 from the rotation angle 180 degrees for changing the direction in the opposite direction. Therefore, there is a relationship of φ = 180−θ between φ and θ.

  When the trajectory of the primary turn L1 is estimated, the traveling trajectory estimation means 18 then estimates the trajectory of the secondary turn L2 from the position M2. Since the host vehicle travels backward in the secondary turn L2 and is steered in the opposite direction to the primary turn L1, the steering angle STR is calculated by the equation (5). Further, in the present embodiment, the secondary turn L2 may be made by turning the remaining angle φ that could not be changed in the opposite direction by the primary turn L1, so the turning distance of the secondary turn L2 is expressed by the equation (6). Is calculated.

二次旋回Ｌ２が終了すると、自車両は反対車線の走行方向を向いているので、舵角ＳＴＲ＝０にて走行することができる。なお、図７（ｂ）では、二次旋回により切り返し走行が終了することとしたが、道路幅Ｄが狭い場合など、複数回一次旋回Ｌ１及び二次旋回Ｌ２の旋回走行を繰り返してもよい。

When the secondary turn L2 ends, the host vehicle faces the direction of travel in the opposite lane, and can travel at the steering angle STR = 0. In FIG. 7B, the turn-back running is finished by the secondary turn. However, when the road width D is narrow, the turn of the primary turn L1 and the secondary turn L2 may be repeated a plurality of times.

  The traveling trajectory estimation means 18 estimates a traveling trajectory by turning back so as to travel the turning distance of the primary turn L1 and the turning distance of the secondary turn L2. When the traveling track is estimated, the U-turn availability determination means 15 determines whether or not the direction can be changed by switching back (S28).

  For example, when it is estimated that the travel rotation angle θ of 90 degrees or more cannot be obtained by the primary turn L1, the primary turn L1 and the secondary turn L2 determine whether or not the direction can be changed by turning back. This is determined by, for example, a case where it is estimated that the traveling of the turning trajectory must be performed three times or more. Criteria for judgment may be designed in advance how, also, may be input by the driver of the limit of the turning number before determination. In addition, when the direction cannot be changed by switching back, it is preferable to notify the driver to that effect.

  When it is determined that the direction can be changed by turning back (Yes in step S28), the turning trajectory composed of the primary turning L1 and the secondary turning L2 estimated by the traveling trajectory estimation means 18 is determined according to the required number of turns. It is sent to the turning travel control means 19. The turning travel control means 19 sets the turning trajectory estimated by the travel trajectory estimation means 18 as a trajectory for traveling (S29). This completes the turning trajectory for turning the direction.

  Next, the host vehicle notifies the surrounding vehicles that the surrounding vehicle is performing a switching operation or is being performed by inter-vehicle communication or the like (S26). Further, the turning traveling control means 19 sends a signal to the actuator of the active steering and signals the engine ECU 25 and the brake ECU 26 to travel at a predetermined speed in order to make the vehicle travel on the estimated turning trajectory. Send it out. As a result, the vehicle changes direction by turning back as shown in FIG. 7B (S30). Note that the driver may be prompted to input whether or not to start turning before the turning control unit 19 starts turning.

  If it is not determined that the direction can be changed by turning back (No in step S28), the driver is informed of the reason why the direction cannot be changed by turning back the road width D or the like, and is guided to a U-turn or an area that can be turned back.

  As described above, according to this embodiment, the vehicle can be controlled to change the direction by making a U-turn or turning back. More specifically, it can be automatically determined by the navigation system whether or not it is a U-turn prohibited area, and it can be automatically determined whether or not it is a travel lane capable of making a U-turn by estimating the travel lane. In a travel area or travel lane in which a U-turn is permitted, U-turn travel can be notified to surrounding vehicles by inter-vehicle communication or the like, and the vehicle can be automatically traveled in a U-turn. Further, when the direction change by the U-turn cannot be performed due to the relationship between the road width and the minimum turning radius, a turning trajectory can be set and the direction can be automatically changed by the turning back. That is, the direction of the vehicle can be changed by making a U-turn or turning back without depending on the skill level of the driver.

  In the first embodiment, the case has been described in which the vehicle automatically changes its direction by a U-turn or turn-back. In this embodiment, a direction change support system that provides a driving support by displaying a driving line suitable for a U-turn or turning on a display of a car navigation system or a head-up display to be a target of a driver's steering angle operation will be described. To do.

  FIG. 8 shows a functional configuration diagram of the direction change support system of the present embodiment. In FIG. 8, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted. In the functional configuration diagram of FIG. 8, the direction change support unit 100 includes a travel line drawing unit 102 and an expected trajectory estimation unit 101, and the travel line drawing unit 102 is connected to the travel line display unit 103. In addition, you may add the travel line drawing means 102 grade | etc., To the structure of FIG.

  The predicted trajectory estimation unit 101 estimates a travel trajectory of the vehicle (hereinafter referred to as an expected trajectory) predicted from the current travel state of the host vehicle. Specifically, the predicted trajectory estimation unit 101 is predicted based on the steering angle STR input from the steering angle sensor 23, the rotation radius information stored in the rotation function information storage unit 14, and the wheel base L of the vehicle. Estimate the vehicle trajectory.

The turning radius R_EXP of the vehicle is between R_EXP = L / tan between the steering angle STR and the wheel base L.
Since the relationship is STR, the predicted trajectory estimation unit 101 can estimate the predicted trajectory L_EXP from the turning radius R_EXP. The predicted trajectory L_EXP estimated by the predicted trajectory estimation unit 101 is sent to the travel line drawing unit 102.

  As described in the first embodiment, the traveling trajectory estimation unit 18 estimates a traveling trajectory suitable for a U-turn or a turnback. In the case of U-turn traveling, a target trajectory L_Target is estimated when the vehicle is traveling at a predetermined rudder angle, for example, the minimum turning radius RM. In the case of the reverse running, the target trajectory L_Target of the primary turning L1 when the vehicle is driven with the minimum turning radius RM and the secondary turning L2 by the backward running (the minimum turning radius RM with the rudder angle opposite to the primary turning L1). A target trajectory L_Target is estimated. The target trajectory L_Target estimated by the travel trajectory estimation means 18 is sent to the travel line drawing means 102. Note that the target trajectory L_Target for the primary turn L1 is obtained by the equations (3) and (4), and the target trajectory L_Target for the secondary turn L2 is obtained by the equations (5) and (6), respectively.

  The travel line drawing unit 102 displays the predicted trajectory L_EXP and the target trajectory L_Target on the travel line display unit 103 described below. The traveling line drawing unit 102 combines the predicted trajectory L_EXP and the target trajectory L_Target so as to be displayed in one image, and displays it on the navigation screen 104 or the like. Since the position of the host vehicle on the navigation screen is known, the travel line drawing unit 102 can display the predicted trajectory L_EXP and the target trajectory L_Target from the current vehicle position on the navigation screen. The driver can smoothly turn the vehicle by performing steering and speed control of the vehicle with the target track L_Target as a target.

  FIG. 9 shows an example of the predicted trajectory L_EXP and the target trajectory L_Target displayed on the navigation screen 104 by the travel line drawing unit 102. If the driver refers to the navigation screen 104 and the predicted trajectory L_EXP is out of L_Target, the driver can make a U-turn by steering to trace L_Target.

  Although FIG. 9 shows a travel line in the case of U-turn travel, it can also be displayed in the same manner in the case of reverse travel. FIG. 10A is a diagram illustrating the trajectory of the primary turn L1 of the reverse running, and FIG. 10B is a diagram illustrating the trajectory of the secondary turn L2. In the case of reverse travel, the travel direction differs between the primary turn L1 by forward travel and the secondary turn L2 by reverse travel. Therefore, the travel line drawing means 102 displays the expected trajectory L_EXP and the target trajectory L_Target as shown in FIG. 10A until the end of the primary turn L1, and the end of the primary turn L1 is determined from the operation of the shift lever, the travel distance, and the like. When detected, the predicted trajectory L_EXP and the target trajectory L_Target of the secondary turn L2 are displayed as shown in FIG.

  Immediately after the end of the primary turn L1, the expected trajectory L_EXP estimated from the steering angle STR and the target trajectory L_Target of the secondary turn L2 are different from each other, so that the driver visually recognizes that the required steering amount is large. And can be quickly steered to the target trajectory L_Target.

  The navigation screen 104 may be a head-up display that is projected and displayed on the windshield 105. FIGS. 11A and 11B show an expected trajectory L_EXP and a target trajectory L_Target displayed on the head-up display 51. FIG.

  As shown in FIG. 11A, by displaying the trajectory on the head-up display 51 projected on the windshield, the driver can steer to trace L_Target with a small line of sight movement.

  Further, the predicted trajectory L_EXP and the target trajectory L_Target displayed on the windshield 105 may be displayed as a vehicle travel line viewed from the driver's seat, as shown in FIG. The road, the predicted trajectory L_EXP, and the target trajectory L_Target are displayed at the same scale, so that steering assistance can be performed in accordance with the steering interval of the driver. Note that vectors Vr_EXP and Vr_Target having predetermined lengths indicating the directions of the predicted trajectory L_EXP and the target trajectory L_Target may be displayed. By displaying the vector with a predetermined length, the necessary steering amount can be displayed to the driver more easily.

  Further, the predicted trajectory L_EXP and the target trajectory L_Target may be projected onto the road surface and displayed. FIG. 12 shows an example of the predicted trajectory L_EXP and the target trajectory L_Target projected on the road surface. The vehicle includes a visible light laser (for example, helium neon laser) irradiation device 52 below the bumper, and projects and displays the predicted orbit L_EXP and the target orbit L_Target directly on the road surface. For example, the driver can determine the target trajectory by displaying the predicted trajectory L_EXP with a dotted line and the target trajectory L_Target with a solid line. By displaying the target trajectory L_Target with direct light on the traveling road surface, the driver only needs to travel on the target trajectory L_Target as it is, and the driving support can be performed more smoothly.

  Based on the above configuration, the procedure of the direction change support of the present embodiment will be described based on the flowchart of FIG. The direction change support system according to the present embodiment operates, for example, when the driver gives a U-turn instruction or when the driver deviates from the travel route to the destination and returns to the original travel route by the U-turn. In the present embodiment, it is assumed that the travel lane of the vehicle has already been determined according to the flowchart of FIG.

  The vehicle determines whether the driver has instructed a U-turn (S101). If the U-turn has not been instructed, the determination in step S101 is repeated.

  When there is an instruction for a U-turn (Yes in S101), the peripheral image is acquired by the CCD camera 21, and the steering angle STR of the vehicle detected by the steering angle sensor 23 is acquired (S102). The traveling trajectory estimation means 18 estimates the predicted trajectory L_EXP based on the steering angle STR and the wheelbase L (S103).

  The traveling line drawing unit 102 displays the predicted trajectory L_EXP on the navigation screen 104 or the like (S104). By displaying the predicted trajectory L_EXP at the estimated stage, the driver can determine to some extent whether or not a U-turn is possible at the current steering angle based on the predicted trajectory L_EXP.

  Next, the vehicle acquires the position of the host vehicle, U-turn regulation information, and road width information from the navigation system 11 (S105). The area determination means 16 determines whether or not the own vehicle exists in an area where the U-turn is possible based on the position of the own vehicle including the traveling lane and the U-turn regulation information.

  The U-turn availability determination means 15 determines whether or not the direction change by the U-turn is possible based on the minimum turning radius RM and the road width (S106). The U-turn availability determination unit 15 obtains the minimum turning radius RM from the turning radius information storage unit 14 and obtains the road width D of the running road from the navigation system 11. The U-turn availability determination unit 15 determines that the U-turn travel is possible when the road width D> 2 × RM.

  If it is determined that a U-turn is not possible (No in step S106), the process is terminated, but it is determined whether or not turn-over travel is possible. Also good.

  When it is determined that a U-turn is possible (Yes in step S106), the traveling trajectory estimation means 18 estimates a target trajectory L_Target (S107). For example, the traveling trajectory estimation means 18 estimates the traveling trajectory in the case of the minimum turning radius RM as the target trajectory L_Target.

  Next, the travel line drawing unit 102 displays the target track L_Target on the navigation screen 104 or the like (S108). As shown in FIGS. 9 to 12b, the traveling line drawing means 102 displays the target trajectory L_Target together with the predicted trajectory L_EXP on one screen, so that the driver can steer the predicted trajectory L_EXP so that it does not deviate from the target trajectory L_Target. Smooth U-turn is possible.

  The travel trajectory estimation means 18 detects the operation amount from the driver's steering STR until the U-turn travel is completed (S109) (S110). The traveling trajectory estimation means 18 repeats estimation of the predicted trajectory L_EXP based on the steering angle STR at any time, and displays it on the navigation screen 104 or the like. The driver can make a U-turn while comparing the predicted trajectory L_EXP reflecting the steering result and the target trajectory L_Target.

  Further, the U-turn availability determination means 15 determines the operation amount (vehicle position, traveling direction, steering angle) after the driver starts the U-turn traveling and the remaining turning angle necessary until the U-turn ends. Based on this, it is determined whether or not a U-turn is possible (S106). The direction change support system may notify the driver by an alarm or the like when the predicted trajectory L_EXP deviates from the target trajectory L_Target by a predetermined amount or more.

  If it is determined that the U-turn is not possible after the start of the U-turn (No in S106), the display of the target trajectory L_Target and the predicted trajectory L_EXP is stopped, and the process of the flowchart in FIG. 13 ends. When it is determined that a U-turn is not possible during the U-turn traveling, the traveling trajectory for turning back may be estimated as in the first embodiment, and the vehicle may be automatically controlled.

  According to the present embodiment, since the driver steers based on the taught target trajectory L_Target and the predicted trajectory L_EXP for direction change, a mechanism for mechanically controlling the steering operation like the active steering 27 is required. Not. The active steering 27 requires electric power for generating a high torque in order to realize a large steering angle, but such electric power is not required in the direction change support system of the present embodiment.

  In addition, when the U-turn traveling is automatically performed as in the first embodiment, since highly accurate throttle control and brake control are necessary to maintain the vehicle speed during the U-turn, the higher-performance engine ECU 25 and brake ECU 26 Although required, in this embodiment, since an existing ECU can be used, an increase in cost can be suppressed.

  Further, in the first embodiment, when some trouble occurs during automatic braking and it is necessary to urgently avoid the vehicle, a method of stopping the direction change support system, or determination of override when the driver operates the accelerator or the steering wheel However, in this embodiment, complicated processing and determination are not required, although it is necessary to grasp the positional relationship with other vehicles and to take measures to prevent contact.

  As shown in FIG. 12, the traveling line display method of projecting the traveling line directly on the road surface is suitable for assisting driving in parking assistance or a narrow alley.

  As described above, in the present embodiment, the driver can be assisted by assisting the driver's judgment and driving, and the direction can be changed by a U-turn or turn-back.

It is a functional block diagram of a direction change assistance system. It is an example of the flowchart figure which shows the procedure of the determination of the traveling lane of the own vehicle. It is an example of the flowchart figure which shows the procedure of determination of U-turn possibility, and the estimation of a running track. It is an example of the travel line estimated by the steering angle which the steering angle sensor detected. It is an example of the determination logic which determines whether it is a left-right turn or a lane change. It is a figure which shows an example of the driving | running track by a U turn. It is a figure which shows an example of the driving track | truck of a return. It is a function block diagram of the direction change assistance system of Example 2. It is a figure which shows an example of the estimated trajectory and the target trajectory displayed on the navigation screen. It is a figure which shows an example of the estimated track | orbit and target track | truck in the case of a turning back drive. It is a figure which shows an example of the estimated trajectory displayed on a head-up display, and a target trajectory. It is a figure which shows an example of the estimated track | orbit projected on the road surface, and a target track. It is a flowchart figure which shows the procedure of a direction change assistance.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Navigation system 12 Image processing apparatus 13 Traveling lane detection means 14 Rotation performance information storage means 15 U-turn availability determination means 16 Area determination means 17 U-turn travel control means 18 Travel track estimation means 19 Turning travel control means 20 Direction change support means

Claims (10)

A turning radius information storage means in which turning radius information relating to the turning radius of the host vehicle is recorded;
U-turn availability determination means for determining whether or not a U-turn is possible based on road width information of the road on which the host vehicle travels acquired from the navigation system and the turning radius information;
Based on the determination result of the U-turn availability determination unit, the direction change support unit that supports the direction change of the host vehicle,
A direction change support system characterized by comprising: When it is determined by the U-turn availability determination means that a U-turn is impossible,
The direction change support means is a turning trajectory estimation means for estimating a turning trajectory for turning back and turning the host vehicle;
A turning travel control means for causing the vehicle to travel with the turning trajectory estimated by the turning trajectory estimation means as a target;
The direction change support system according to claim 1, further comprising: When it is determined by the U-turn availability determination means that a U-turn is possible,
The direction change support means includes a U-turn travel control means for causing the host vehicle to travel at a predetermined rudder angle.
The direction change support system according to claim 1.   The direction change support system according to any one of claims 1 to 3, wherein the direction change support means teaches a driver a steering amount for direction change. Expected trajectory estimation means for estimating the expected trajectory of the host vehicle based on the rudder angle detected from the rudder angle sensor,
The direction change support means includes the predicted trajectory estimated by the expected trajectory estimation means, and the U-turn travel trajectory when traveling at the predetermined rudder angle or the turning trajectory estimated by the turning trajectory estimation means. To the driver,
The direction change support system according to claim 4.   The direction change support system according to claim 1, wherein a determination result of whether or not a U-turn is possible by the U-turn availability determination unit is notified to a driver. A navigation system;
Traveling lane detecting means for detecting the traveling lane of the host vehicle;
Area determining means for determining whether or not the host vehicle is in a U-turnable area based on the driving lane of the host vehicle detected by the driving lane detecting unit and the U-turn regulation information acquired from the navigation system;
A direction change support system characterized by comprising: The travel lane detection means detects the travel lane from at least one of the coordinate data of the host vehicle acquired from the navigation system or the vehicle operation of the host vehicle.
The direction change support system according to claim 7.   The direction change support system according to claim 8, wherein the vehicle operation of the host vehicle is a direction indicator or a steering angle operation. Having image photographing means for photographing an image in front of the vehicle;
The travel lane detection means detects the travel lane of the host vehicle based on a white line detected from an image captured by the image capturing means.
The direction change support system according to claim 8.

Images