JP2020095381A - Wrong-way driving determination system, wrong-way driving determination method, and wrong-way driving determination program - Google Patents

Abstract

To provide a technique capable of quickly determining the possibility of wrong-way driving of a vehicle while suppressing erroneous determination.SOLUTION: A wrong-way driving determination system 1 includes: a turning radius acquisition part 12 that acquires a predicted turning radius of a target vehicle for each specified cycle; and a determination part 11 that determines the possibility of wrong-way driving of the target vehicle. A first condition is set in such a way that the predicted turning radius is equal to or less than a specified radius threshold, and a second condition is set in such a way that the amount of change in angle in the traveling direction of the target vehicle while traveling a specified first determination distance is equal to or greater than a specified first angle. The determination part 11 determines that there is the possibility of wrong-way driving of the target vehicle on condition that the first condition is satisfied when the vehicle speed of the target vehicle is equal to or higher than a specified first determination vehicle speed, and determines that there is the possibility of wrong-way driving of the target vehicle on condition that both the first and second conditions are satisfied when the vehicle speed is lower than the specified first determination vehicle speed.SELECTED DRAWING: Figure 1

Description

The present invention relates to a reverse running determination system, a reverse run determining method, and a reverse run determining program that determine the possibility of a vehicle running backwards.

An example of a reverse running warning device that detects a reverse running of a vehicle and gives a warning is disclosed in Japanese Patent No. 5227220 (Patent Document 1). Specifically, Patent Literature 1 describes a technique for detecting reverse running of a vehicle on the condition that the turning angle or the yaw angle of the vehicle becomes larger than a reversal determination threshold. It is described that the reversal determination threshold value is, for example, a value between 80 degrees and 180 degrees.

Japanese Patent No. 5227220

By the way, if it is possible to detect the possibility that the vehicle will run in reverse at an early timing, it is possible to warn the driver at an early stage after the start of an incorrect driving operation, and to reverse running in the subsequent driving operation. It is also possible to prevent this. In this regard, in the technique described in Patent Document 1, the fact that the turning angle or the yaw angle of the vehicle is larger than the reversal determination threshold value is included in the reverse running detection condition. Therefore, in the technique described in Patent Document 1, it is easy to suppress a low rate of erroneous determination that the vehicle may run backward when a normal driving operation is performed, but the turning angle or the yaw angle of the vehicle may be reduced. It is difficult to determine the possibility of the vehicle traveling backward before the traveling direction (direction) of the vehicle changes to such an extent that the reversal determination threshold is exceeded.

Therefore, it is desired to realize a technique capable of accelerating the determination timing of the possibility that the vehicle may run backward while suppressing erroneous determination to a small extent.

A reverse running determination system according to the present disclosure includes a turning radius acquisition unit that acquires a predicted turning radius of a target vehicle for each specified cycle, and a determination unit that determines a possibility that the target vehicle runs in reverse. The first condition is that the turning radius is less than or equal to the specified radius threshold, and the amount of change in the traveling direction of the target vehicle during traveling the specified first determination distance is equal to or greater than the specified first angle. As a second condition, when the vehicle speed of the target vehicle is equal to or higher than a predetermined first determination vehicle speed, the determination unit may reverse the target vehicle on condition that the first condition is satisfied. If the vehicle speed is less than the first determination vehicle speed, it is possible that the target vehicle runs in reverse on the condition that both the first condition and the second condition are satisfied. It is determined that there is a property.

A reverse running determination method according to the present disclosure includes a turning radius acquisition step of acquiring a predicted turning radius of a target vehicle for each specified cycle, and a determination step of determining a possibility that the target vehicle runs backward. The first condition is that the turning radius is less than or equal to the specified radius threshold, and the amount of change in the traveling direction of the target vehicle during traveling the specified first determination distance is equal to or greater than the specified first angle. As a second condition, in the determination step, if the vehicle speed of the target vehicle is equal to or higher than a prescribed first determination vehicle speed, the target vehicle may run in reverse on the condition that the first condition is satisfied. If the vehicle speed is less than the first determination vehicle speed, it is possible that the target vehicle runs in reverse on the condition that both the first condition and the second condition are satisfied. It is determined that there is a property.

The reverse running determination program according to the present disclosure causes a computer to realize a turning radius acquisition function that acquires a predicted turning radius of a target vehicle for each specified cycle, and a determination function that determines a possibility that the target vehicle runs backward. The first condition is that the predicted turning radius is equal to or less than a prescribed radius threshold, and the amount of change in the traveling direction of the target vehicle during traveling the prescribed first determination distance is equal to or greater than the prescribed first angle. If the vehicle speed of the target vehicle is equal to or higher than the specified first determination vehicle speed, the target vehicle is switched to the second condition with the first condition being satisfied, as a second condition. When it is determined that there is a possibility of running, and the vehicle speed is less than the first determination vehicle speed, the target vehicle is reversed if both the first condition and the second condition are satisfied. It is determined that there is a possibility of running.

When the vehicle is traveling according to the traffic direction set on the road, the turning radius of the vehicle is basically larger than a certain value determined according to the shape of the road (for example, the road width). .. Therefore, when the turning radius of the vehicle is equal to or less than the certain value, it can be inferred that the direction change (U-turn or the like) leading to the reverse running may be performed. In view of this point, in the above configuration, the target vehicle reversely runs based on at least whether or not the predicted turning radius of the target vehicle is equal to or less than the radius threshold value (that is, at least whether or not the first condition is satisfied). Determine the possibility. Here, since the index to be compared with the radius threshold is the predicted turning radius of the target vehicle for each specified cycle, the target vehicle can run backward at a relatively early stage before the traveling direction of the target vehicle changes significantly. The presence or absence of sex can be determined. That is, it is possible to accelerate the timing of determining the possibility of the vehicle traveling in reverse.

By the way, the above-mentioned radius threshold value is set so that it is possible to appropriately determine whether or not there is a possibility that the target vehicle will run in reverse. It was found that the predicted turning radius can be equal to or less than the radius threshold even when a normal driving operation such as a lane change is performed. Based on such knowledge, in the above-described configuration, when the vehicle speed is less than the first determination vehicle speed, the condition for determining that the target vehicle may run in reverse may be set while the vehicle travels the first determination distance. The second condition that the amount of change in angle is greater than or equal to the first angle is included. As a result, it is possible to suppress a low rate of erroneous determination that the target vehicle may run backward when a normal driving operation such as a lane change is performed. On the other hand, in the above configuration, when the vehicle speed is equal to or higher than the first determination vehicle speed, the second determination condition is excluded from the conditions for determining that the target vehicle may reversely travel, so that the vehicle travels the first determination distance. It is possible to determine whether or not there is a possibility that the target vehicle may run in reverse at a stage before the amount of change in angle during the period becomes greater than or equal to the first angle.

As described above, according to the above configuration, it is possible to reduce the number of erroneous determinations and accelerate the determination timing of the possibility that the vehicle may run in reverse.

Further features and advantages of the reverse run determination system, the reverse run determination method, and the reverse run determination program will become more apparent from the following description of the embodiments with reference to the drawings.

Block diagram showing a schematic configuration of a reverse running determination system Explanatory drawing of derivation method of predicted turning radius Flowchart showing an example of the procedure of reverse running determination processing Figure showing an example of a situation in which a vehicle runs in reverse The figure which shows another example of the situation where a vehicle runs in reverse. Diagram showing an example of a situation in which a vehicle changes lanes

An embodiment of a reverse running determination system will be described with reference to the drawings. As shown in FIG. 1, the reverse running determination system 1 includes a control unit 10. Although illustration is omitted, the control unit 10 includes an arithmetic processing device such as a single or a plurality of CPUs (Central Processing Units) as a core member, and a storage device to which the arithmetic processing device can refer. The storage device is, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory). The control unit 10 executes the respective programs stored in the main storage device (a storage device included in the control unit 10) and the storage device 3 (a storage device provided separately from the control unit 10) to perform the reverse running determination. Realize each function to perform. The storage device 3 includes, as a hardware configuration, a storage medium that can store and rewrite information, such as a flash memory or a hard disk. Note that, in the following description, at least a part of data (including programs) described as being stored in the main storage device is stored in the storage device 3, or when stored in the storage device 3 in the following description. At least a part of the data (including programs) to be described may be stored in the main storage device. In this embodiment, the control unit 10 functions as a “computer”.

As shown in FIG. 1, the reverse running determination system 1 (control unit 10) includes a plurality of functional units. Specifically, the reverse running determination system 1 (control unit 10) includes a determination unit 11 and a turning radius acquisition unit 12, and in the present embodiment, the angle change amount acquisition unit 16 and the road width information acquisition unit 13 are further provided. A warning processing unit 14 and a position information acquisition unit 15 are provided. The plurality of functional units are configured to exchange information with each other and to extract data from a storage device (main storage device or storage device 3). The plurality of functional units are at least logically distinguished and need not be physically distinguished. Further, the plurality of functional units do not have to be realized by common hardware, and may be realized separately by a plurality of hardware (for example, the control unit 10 and the server device) that can communicate with each other.

The control unit 10 executes the programs stored in the storage device (main storage device or storage device 3) (the programs that form the reverse running determination program) to perform the functions of the functional units illustrated in FIG. 1. To be realized. That is, each functional unit of the reverse running determination system 1 is configured by software (program) stored in the storage device, hardware such as a separately provided arithmetic circuit, or both of them. In other words, a program (reverse running determination program) for causing the arithmetic processing device (computer) to realize the function of each functional unit of the reverse running determination system 1 is stored in a storage device that can be referred to by the arithmetic processing device. The reverse running determination program is provided, for example, by a storage medium or via a communication network. When the reverse running determination system 1 is used by being incorporated in a vehicle navigation system, the provided reverse running determining program is installed in, for example, an in-vehicle device of the navigation system, and the reverse running determining system 1 is realized. The reverse running determination system 1 is not limited to an in-vehicle device, and may be realized using a portable device that can be carried by a user (portable navigation device, portable information terminal device, multifunctional mobile phone, etc.).

As shown in FIG. 1, the reverse running determination system 1 is realized using a plurality of devices (specifically, the devices included in the information acquisition unit 20, the storage device 3, and the warning device 4). The information acquisition unit 20 includes various devices (various sensors) that acquire information necessary for performing reverse running determination. In this embodiment, the information acquisition unit 20 includes a vehicle speed detection unit 21, a yaw rate detection unit 22, and a GPS receiver 23. The GPS receiver 23 is a device that receives GPS signals from GPS (Global Positioning System) satellites. The control unit 10 is configured to be able to acquire the information acquired by the information acquisition unit 20 (detection information of each device included in the information acquisition unit 20). In the present specification, the “device” is not limited to one piece of integrated hardware, and one “device” may be composed of a plurality of pieces of hardware (device group) separated from each other. .. In addition, at least a part (for example, the storage device 3) of the plurality of devices for realizing the reverse running determination system 1 is not the target vehicle 2 (the vehicle that is the target of the reverse running determination) but may be portable by the user. It may be provided in the carrying device or an external device (for example, a server device) capable of communicating with the target vehicle 2.

The reverse running determination system 1 is a system that determines the possibility of the target vehicle 2 running backwards. The reverse running determination system 1 is configured to issue a warning to the target vehicle 2 (an occupant of the target vehicle 2, especially a driver) when it is determined that the target vehicle 2 may run backward. .. Then, the reverse running determination system 1 is configured to be able to accelerate the determination timing of the possibility that the target vehicle 2 will run in reverse while suppressing erroneous determination to a small extent. Hereinafter, the configuration of each functional unit (see FIG. 1) of the reverse running determination system 1 for realizing such a configuration will be specifically described.

The turning radius acquisition unit 12 is a functional unit that acquires the predicted turning radius R of the target vehicle 2 for each specified cycle (for each specified cycle). The turning radius acquisition unit 12 calculates the predicted turning radius R (instantaneous) of the target vehicle 2 for each specified cycle based on the vehicle behavior of the target vehicle 2 (vehicle speed V and yaw rate Y in this embodiment) detected at each specified cycle. Turning radius). That is, the predicted turning radius R is the turning radius of the target vehicle 2 at each time point, in other words, the instantaneous turning radius of the target vehicle 2 or the average turning radius of the target vehicle 2 in an extremely short time. .. Then, the predicted turning radius R is derived based on the vehicle behavior of the target vehicle 2 at each time point, in other words, based on the instantaneous vehicle behavior of the target vehicle 2. The specified cycle can be a sampling cycle of the vehicle behavior of the target vehicle 2 (for example, 100 [msec]). In the present embodiment, the sampling cycle of the vehicle behavior of the target vehicle 2 is the sampling cycle of the vehicle speed detection unit 21 and the yaw rate detection unit 22. The turning radius acquisition unit 12 acquires the predicted turning radius R for each specified cycle. That is, the turning radius acquisition unit 12 repeatedly acquires the predicted turning radius R. Then, the information on the predicted turning radius R acquired by the turning radius acquisition unit 12 is input to the determination unit 11. In the present embodiment, the processing executed by the turning radius acquisition unit 12 corresponds to the “turning radius acquisition step”, and the function realized by executing the processing corresponds to the “turning radius acquisition function”.

In the present embodiment, the reverse running determination system 1 (specifically, the information acquisition unit 20) detects the vehicle speed detection unit 21 that detects the vehicle speed V that is the traveling speed of the target vehicle 2 and the yaw rate Y of the target vehicle 2. The yaw rate detection unit 22 is provided. The vehicle speed detection unit 21 detects the vehicle speed V at every specified cycle (every sampling cycle). That is, the vehicle speed V detected by the vehicle speed detection unit 21 is the traveling speed of the target vehicle 2 at each time point, in other words, the instantaneous traveling speed of the target vehicle 2 or the extremely short time of the target vehicle 2. Is the average traveling speed of. The yaw rate detection unit 22 detects the yaw rate Y at each specified cycle (each sampling cycle). That is, the yaw rate Y detected by the yaw rate detection unit 22 is the yaw rate of the target vehicle 2 at each time point, in other words, the instantaneous yaw rate of the target vehicle 2 or the average yaw rate of the target vehicle 2 in an extremely short time. Is.

The vehicle speed detection unit 21 generates a signal according to the vehicle speed V of the target vehicle 2, and the control unit 10 acquires the vehicle speed V of the target vehicle 2 based on the signal input from the vehicle speed detection unit 21. As the vehicle speed detection unit 21, for example, a vehicle speed pulse sensor that generates a pulse signal according to the rotation of the wheels of the target vehicle 2 can be used. Further, the yaw rate detection unit 22 generates a signal according to the yaw rate Y of the target vehicle 2, and the control unit 10 acquires the yaw rate Y of the target vehicle 2 based on the signal input from the yaw rate detection unit 22. As the yaw rate detection unit 22, for example, a gyro sensor that generates a signal according to the traveling direction of the target vehicle 2 or a change in the traveling direction can be used.

In the present embodiment, the turning radius acquisition unit 12 is configured to acquire the predicted turning radius R based on the vehicle speed V detected by the vehicle speed detection unit 21 and the yaw rate Y detected by the yaw rate detection unit 22. Specifically, the turning radius acquisition unit 12 is configured to acquire a value obtained by dividing the vehicle speed V by the yaw rate Y as the predicted turning radius R. The turning radius acquisition unit 12 defines the relationship between the vehicle speed V and the yaw rate Y and the value obtained by dividing the vehicle speed V by the yaw rate Y (that is, the predicted turning radius R) by performing the calculation each time. With reference to, the predicted turning radius R is acquired.

The reason why the predicted turning radius R can be derived by dividing the vehicle speed V by the yaw rate Y will be described with reference to FIG. FIG. 2 shows a situation where the target vehicle 2 is turning at a vehicle speed V [m/sec]. In a sufficiently short period, as shown in FIG. 2, the traveling locus of the target vehicle 2 when turning can be regarded as a circular arc of a perfect circle. Therefore, between the turning angle A [rad] of the target vehicle 2, the predicted turning radius R [m], and the travel distance L [m] of the target vehicle 2 during the time ΔT [sec], When the relation as in the formula (1) is established and the formula (1) is modified, the following formula (2) is obtained.
L=R×A=ΔT×V (1)
R×(A/ΔT)=V (2)

Further, as shown in the following expression (3), the yaw rate Y [rad/sec] of the target vehicle 2 is equal to the time derivative of the change amount θ [rad] in the traveling direction of the target vehicle 2.
Y=θ/ΔT (3)
Then, assuming a situation where the target vehicle 2 does not skid, the change amount θ [rad] in the traveling direction is equal to the turning angle A [rad], and the respective time derivatives are also equal to each other. Therefore, the following equation (4) is obtained from the equations (1) and (2).
R×Y=V...(4)
As shown in the equation (4), the predicted turning radius R is derived by dividing the vehicle speed V by the yaw rate Y.

The angle change amount acquisition unit 16 is a functional unit that acquires the angle change amount θ in the traveling direction (direction) of the target vehicle 2 while traveling the specified first determination distance Ld. Here, the angle change amount θ in the traveling direction of the target vehicle 2 during traveling of the first determination distance Ld is referred to as a “first angle change amount”. The first angle change amount is the angle change amount θ as a whole in the traveling direction of the target vehicle 2 while traveling the first determination distance Ld. That is, the first angle change amount is based on the traveling direction of the target vehicle 2 at the traveling start point (or traveling start point) of the first determination distance Ld, and the traveling end point of the first determination distance Ld (or traveling end). It is the amount of angle change in the traveling direction of the target vehicle 2 at the point). In other words, the first angle change amount is an angle difference in the traveling direction of the target vehicle 2 at these two time points (or these two points). Regarding the traveling direction of the target vehicle 2 at the traveling end time (or traveling end point) of the first determination distance Ld, when the calculation time (calculation delay) is ignored, the angle change amount acquisition unit 16 acquires the first angle change amount. It coincides with the traveling direction of the target vehicle 2 at the time point. That is, the angle change amount acquisition unit 16 acquires the first angle change amount at which the current position of the target vehicle 2 is the travel end point of the first determination distance Ld. The information on the first angle change amount acquired by the angle change amount acquisition unit 16 is input to the determination unit 11. The process (first angle change amount acquisition step) of acquiring the first angle change amount is executed by the angle change amount acquisition unit 16, and the function of acquiring the first angle change amount by executing the process (first angle change) Quantity acquisition function) is realized. The set value of the first determination distance Ld will be described later.

In the present embodiment, the angle change amount acquisition unit 16 acquires the first angle change amount based on the detection information of the vehicle speed detection unit 21 and the detection information of the yaw rate detection unit 22. Specifically, the angle change amount acquisition unit 16 determines the traveling period of the first determination distance Ld by the target vehicle 2 (the period from the start of traveling of the first determination distance Ld to the end of traveling of the first determination distance Ld). The first angle change amount is acquired by integrating the yaw rate Y detected by the yaw rate detection unit 22 with time. Since the yaw rate detection unit 22 detects the yaw rate Y for each specified cycle, the values obtained by multiplying the repeatedly detected yaw rate Y by the specified cycle (sampling cycle) are sequentially added (considering the sign). The time integral value of the yaw rate Y can be derived. Note that the angle change amount acquisition unit 16 acquires the traveling distance of the target vehicle 2 based on the detection information of the vehicle speed detection unit 21 (for example, based on the number of pulse signals generated by the vehicle speed detection unit 21), and thus the target vehicle 2 Specifies the traveling period of the first determination distance Ld. The angle change amount acquisition unit 16 repeatedly acquires, for example, the first angle change amount every prescribed cycle.

In the present embodiment, the angle change amount acquisition unit 16 also acquires the angle change amount θ in the traveling direction of the target vehicle 2 while traveling the prescribed second determination distance. Here, the angle change amount θ in the traveling direction of the target vehicle 2 while traveling the second determination distance is referred to as a “second angle change amount”. The second angle change amount is the angle change amount θ as a whole in the traveling direction of the target vehicle 2 while traveling the second determination distance. That is, the second angle change amount is based on the traveling direction of the target vehicle 2 at the traveling start time point (or traveling start point) of the second determination distance, and the traveling end time point (or traveling end point) of the second determination distance is used. Is the angle change amount of the target vehicle 2 in the traveling direction. In other words, the second angle change amount is an angle difference in the traveling direction of the target vehicle 2 at these two time points (or these two points). When the calculation time (calculation delay) is ignored, the angle change amount acquisition unit 16 acquires the second angle change amount for the traveling direction of the target vehicle 2 at the time when the travel of the second determination distance ends (or the travel end point). Coincides with the traveling direction of the target vehicle 2. That is, the angle change amount acquisition unit 16 acquires the second angle change amount at which the current position of the target vehicle 2 is the travel end point of the second determination distance. The angle change amount acquisition unit 16 acquires the second angle change amount by the same method as the first angle change amount. The angle change amount acquisition unit 16 repeatedly acquires, for example, the second angle change amount every prescribed cycle. The information about the second angle change amount acquired by the angle change amount acquisition unit 16 is input to the determination unit 11. The second determination distance can be set to 20 [m], for example. The second determination distance may be a fixed value or a variable value that changes stepwise or continuously according to the vehicle speed V. The process (second angle change amount acquisition step) of acquiring the second angle change amount is executed by the angle change amount acquisition unit 16, and the function of acquiring the second angle change amount by executing the process (second angle change). Quantity acquisition function) is realized.

The determination unit 11 is a functional unit that determines the possibility of the target vehicle 2 traveling in reverse. The determination unit 11 refers to a storage device (for example, the storage device 3) to obtain the above-described information about the first determination distance Ld and the second determination distance, and also obtains information about a first angle and a second angle described below. get. The determination unit 11 determines that the predicted turning radius R is equal to or less than a prescribed radius threshold as a first condition, and the first angle change amount is equal to or greater than a prescribed first angle as a second condition. When V is equal to or higher than the prescribed first determination vehicle speed, it is determined that the target vehicle 2 may run in reverse on the condition that the first condition is satisfied, and the vehicle speed V is less than the first determination vehicle speed. If it is, it is determined that the target vehicle 2 may run in reverse on the condition that both the first condition and the second condition are satisfied. In this embodiment, when the vehicle speed V is equal to or higher than the first determination vehicle speed, the determination unit 11 determines that the target vehicle 2 may run backward only on the condition that the first condition is satisfied. However, when the vehicle speed V is less than the first determination vehicle speed, it is determined that the target vehicle 2 may run in reverse only on the condition that both the first condition and the second condition are satisfied. The first determination vehicle speed can be set to 40 [km/h], for example. The radius threshold setting value and the first angle setting value will be described later. In the present embodiment, the process executed by the determination unit 11 corresponds to the “determination step”, and the function realized by executing the process corresponds to the “determination function”.

In the present embodiment, the determination unit 11 determines that the vehicle speed V is less than the prescribed second determination vehicle speed that is smaller than the first determination vehicle speed on the third condition that the second angle change amount is equal to or greater than the prescribed second angle. In the above, it is determined that the target vehicle 2 may run in reverse on the condition that the third condition is satisfied instead of satisfying both the first condition and the second condition. In the present embodiment, when the vehicle speed V is less than the second determination vehicle speed, the determination unit 11 determines that the target vehicle 2 may run in reverse only on the condition that the third condition is satisfied. To do. The second determination vehicle speed can be set to 10 [km/h], for example. Further, the second angle can be set to a value within the range of 80 degrees to 180 degrees (for example, 80 degrees).

As described above, in the reverse running determination system 1, the conditions for determining that the target vehicle 2 may run backward include a vehicle speed range equal to or higher than the first determination vehicle speed and a vehicle speed range less than the first determination vehicle speed. The conditions are different from each other in at least two vehicle speed ranges. In the present embodiment, the vehicle speed range below the first determination vehicle speed is further divided into a vehicle speed range above the second determination vehicle speed and a vehicle speed range below the second determination vehicle speed, and the target vehicle 2 may run in reverse. The conditions for the determination are three vehicle speed ranges, that is, a vehicle speed range that is equal to or higher than the first determination vehicle speed, a vehicle speed range that is less than the first determination vehicle speed and is equal to or higher than the second determination vehicle speed, and a vehicle speed range that is less than the second determination vehicle speed. , The conditions are different from each other.

As shown in FIG. 4 and FIG. 5 as an example of a situation in which the target vehicle 2 runs in reverse, the target vehicle 2 has a turning radius equal to or less than half the width of the road 90 (road width W). When the direction is changed (U-turn, etc.), it can be considered that there is a high possibility that the target vehicle 2 will run backward. In view of this point, in the present embodiment, the radius threshold value is set with a half value of the road width W as a reference. In this way, by setting the radius threshold to a value that is set based on a value that is half the road width W, it is possible to appropriately determine that the target vehicle 2 may run in reverse. In the present specification, “setting a certain value as a reference” is a concept including both setting the same value and setting (correcting) the value. is there. That is, the radius threshold is set to a value that is half the road width W, or is set to a value (corrected value) obtained by adjusting the value that is half the road width W. As an example of the latter, the radius threshold value can be set to a value obtained by subtracting a value based on the vehicle width of the target vehicle 2 (for example, a half value of the vehicle width) from the half value of the road width W. In addition, in FIG. 5, it is assumed that the target vehicle 2 that has entered from the approach road 95 travels backward on the road 92 (main road), but the target vehicle 2 that is traveling on the road 92 (main road) does not approach the approach road 95. It is also possible to envisage a situation in which the vehicle approaches the vehicle 95 in the opposite direction and runs backward on the approach road 95.

The road width W is the width of the road region of the road 90 in the same traffic direction. When the road 90 has two road regions having different traveling directions, the width of the road region in which the traveling direction matches the normal traveling direction of the target vehicle 2 is defined as the road width W. The road region includes at least the lane 93. When the road 90 has a plurality of lanes 93 whose traveling direction matches the normal traveling direction of the target vehicle 2, basically all of the plurality of lanes 93 are included in the road area. However, when the lanes 93 separated by a three-dimensional structure exist among the plurality of lanes 93, the separated lanes 93 may be excluded. In addition to the lane 93, the road region may include a region (for example, a road shoulder 94) provided adjacent to the lane 93 and in which the vehicle can travel. Here, “runnable” means physically runnable.

For example, in the example shown in FIG. 4, in the road 90 in which the roadway 92 has three lanes 93 (three lanes 93 in the same traffic direction), a road area including the roadway 92 and shoulders 94 on both outer sides in the road width direction. The width is the road width W. Further, in the example illustrated in FIG. 5, in the road 90 where the roadway 92 has two lanes 93 (two lanes 93 in the same traffic direction), at the confluence of the approach roads 95, the roadway 92 (main roadway), The width of the road area including the merging lane 93a (acceleration lane) of the approach road 95 and the road shoulders 94 on both outer sides in the road width direction is defined as the road width W. In the example shown in FIG. 5, at the points other than the confluence point, the width of the road area including the road 92 and the shoulders 94 on both outer sides in the road width direction is set as the road width W, as in the example shown in FIG. You can Thus, even on the same road 90, the road width W can be variably set according to the location (position along the extending direction of the road 90). Note that, for the same road 90, the same value as the road width W (for example, the maximum value of the road width W on the road 90) can be used regardless of the location.

As shown in FIG. 1, in this embodiment, the reverse running determination system 1 (control unit 10) includes a road width information acquisition unit 13. The road width information acquisition unit 13 is a functional unit that acquires road width information indicating the road width W of the road 90 on which the target vehicle 2 is traveling. The road width information acquired by the road width information acquisition unit 13 is input to the determination unit 11, and the determination unit 11 sets the radius threshold value based on the half value of the road width W represented by the road width information. That is, in the present embodiment, the radius threshold value is a value that is set with a half of the road width W represented by the road width information as a reference. The road width information acquisition unit 13 executes a process (road width information acquisition step) of acquiring road width information representing the road width W of the road 90 on which the target vehicle 2 is traveling, and by executing the process, the target vehicle 2 A function (road width information acquisition function) of acquiring road width information representing the road width W of the road 90 on which the vehicle is traveling is realized.

In this embodiment, the reverse running determination system 1 (control unit 10) includes a position information acquisition unit 15. The position information acquisition unit 15 is a functional unit that acquires position information indicating the current position of the target vehicle 2. The position information acquisition unit 15 acquires position information based on the signal input from the information acquisition unit 20. At this time, the current position of the target vehicle 2 may be corrected based on the road information or the feature information stored in the storage device 3. The position information acquisition unit 15 executes a process (position information acquisition step) of acquiring position information indicating the current position of the target vehicle 2, and by executing the process, acquires position information indicating the current position of the target vehicle 2. A function (positional information acquisition function) is realized.

In the present embodiment, the road width information acquisition unit 13 uses the position information acquired by the position information acquisition unit 15 and the road information stored in the storage device 3 to determine the road 90 on which the target vehicle 2 is traveling. The road width information indicating the road width W of is acquired. Specifically, the storage device 3 stores road information necessary for route guidance, traffic information guidance, map display, and the like. The road information includes, for example, information that directly represents the road width W of the road 90 on which the target vehicle 2 is traveling, or for deriving the road width W of the road 90 on which the target vehicle 2 is traveling. Information (for example, information on road type (road rating), road width, number of lanes, lane width, shoulder width, etc.) is included.

The road width information acquisition unit 13 may be configured to acquire the road width information indicating the road width W of the road 90 on which the target vehicle 2 is traveling by communication. For example, the road width information acquisition unit 13 may be configured to acquire road width information by road-vehicle communication with a communication device (a roadside communication device such as an optical beacon) installed on the road side.

The warning processing unit 14 is a functional unit that issues a warning when the determination unit 11 determines that the target vehicle 2 may run backward. The warning processing unit 14 gives a warning using the warning device 4 when the judgment unit 11 judges that the target vehicle 2 may run backward. The warning processing unit 14 executes a process (warning process step) of issuing a warning when it is determined that the target vehicle 2 may run in reverse, and the target vehicle 2 may run in reverse by executing the process. A function (warning processing function) of issuing a warning when it is determined that there is a property is realized.

The warning processing unit 14 uses, for example, a display as the warning device 4, displays warning character information and a blinking pattern of light on the display, and warns an occupant (particularly, a driver) of the target vehicle 2. To do. Further, the warning processing unit 14 uses, for example, a speaker as the warning device 4, and issues a warning message or warning sound for warning from the speaker to warn the occupant of the target vehicle 2.

By the way, the radius threshold is set so that it is possible to appropriately determine whether or not the target vehicle 2 may reversely run. As described above, in the present embodiment, the radius threshold is the road width. Although the value is set to half the value of W as a reference, the inventors of the present invention have found that, as a result of research, even when a normal driving operation such as a lane change is performed when the vehicle speed V is low, The knowledge that the predicted turning radius R can be equal to or smaller than the radius threshold (that is, the first condition can be satisfied) has been obtained. Based on such knowledge, as described above, the reverse running determination system 1 determines that the vehicle speed V is less than the first determined vehicle speed (in the present embodiment, the vehicle speed V is less than the first determined vehicle speed and the second If the vehicle speed is equal to or higher than the determination vehicle speed), the second condition is included in the conditions for determining that the target vehicle 2 may reversely travel. As a result, it is possible to suppress a low rate of erroneously determining that the target vehicle 2 may run backward when a normal driving operation such as a lane change is performed. On the other hand, when the vehicle speed V is equal to or higher than the first determination vehicle speed, the comparison before the second condition is satisfied is excluded by not including the second condition in the condition for determining that the target vehicle 2 may reversely travel. It is possible to determine whether or not there is a possibility that the target vehicle 2 will run in reverse at an early stage.

For example, in FIG. 4, the predicted turning radius R is greater than the radius threshold value at time T1 (that is, the first condition is not satisfied), and the predicted turning radius R is less than or equal to the radius threshold value at time T2 (that is, the first condition is satisfied). The situation is assumed. Further, in FIG. 4, at time T1 and time T2, the first angle change amount, which is the angle change amount θ in the traveling direction of the target vehicle 2 while traveling the first determination distance Ld, is less than the first angle ( That is, it is assumed that the second condition is not satisfied and the first angle change amount is equal to or more than the first angle at time T3 (that is, the second condition is satisfied). In FIG. 5, it is assumed that the predicted turning radius R is larger than the radius threshold value at time T11 and the predicted turning radius R is equal to or smaller than the radius threshold value at time T12. In addition, in FIG. 5, it is assumed that the first angle change amount is less than the first angle at time T11 and time T12, and the first angle change amount is equal to or more than the first angle at time T13. In this way, when the target vehicle 2 runs in the reverse direction, the first condition is satisfied at a relatively early stage before the traveling direction of the target vehicle 2 changes significantly, and therefore the vehicle speed V is equal to or higher than the first determination vehicle speed. In this case, it is possible to determine whether or not the target vehicle 2 may run in reverse at a relatively early time point before the second condition is satisfied.

As described above, the second condition is satisfied when the first angle change amount, which is the angle change amount θ in the traveling direction of the target vehicle 2 while traveling the first determination distance Ld, is equal to or greater than the first angle. Be done. Therefore, the first determination distance Ld and the first angle are set such that the second condition is difficult to be satisfied in a situation where a normal driving operation such as a lane change is performed. Hereinafter, an example of setting the first determination distance Ld and the first angle will be described.

As shown in FIG. 6, in the situation where the target vehicle 2 changes lanes, the steering angle changes from zero (neutral position) from the time when the lane change operation starts at time T21 to the time when the lane change operation ends at time T23. After increasing to one turning direction side (here, right turning direction side), it decreases and returns to zero, and then the steering angle increases from zero to the other turning direction side (here, left turning direction side) After that, the steering device 5 (for example, the steering wheel) is operated so as to decrease and return to zero. Therefore, the angle change amount θ in the traveling direction of the target vehicle 2 before the start of the lane change operation becomes maximum when the steering angle increases from zero to one turning direction side and then decreases to zero. The time point is generally a time point near the time point (the time point T22 in FIG. 6) at which the target vehicle 2 crosses the boundary line between the lanes 93. Therefore, it can be considered that the angle change amount θ in the traveling direction of the target vehicle 2 before the start of the lane change operation becomes maximum when the target vehicle 2 crosses the boundary line between the lanes 93. Here, the maximum value of the angle change amount θ in the traveling direction of the target vehicle 2 before the start of the lane change operation, which is assumed during the lane change, is set as an assumed maximum change amount θmax.

In the situation where the target vehicle 2 changes lanes, the steering angle changes as described above, so the change speed in the traveling direction of the target vehicle 2 becomes a value close to zero when crossing the boundary line between the lanes 93. Is generally expected. On the other hand, in a situation where the target vehicle 2 makes a direction change (U-turn or the like) that leads to reverse running, the change speed in the traveling direction of the target vehicle 2 is the same value as before when crossing the boundary line between the lanes 93. Is generally expected to be maintained (see FIG. 4). In view of this point, in the present embodiment, the travel distance of the target vehicle 2 that is assumed during the lane change from the start of the lane change operation to the time when the vehicle crosses the boundary line between the lanes 93 is the estimated travel distance Le. (See FIG. 6), the first determination distance Ld is set to a distance according to the assumed traveling distance Le. That is, the first determination distance Ld is set to the same value as the estimated traveling distance Le, or set to a value (corrected value) obtained by adjusting the estimated traveling distance Le. In this way, by setting the first determination distance Ld to a distance according to the assumed traveling distance Le, the angle change amount θ in the traveling direction of the target vehicle 2 detected while traveling the first determination distance Ld is set as the target. The situation where the vehicle 2 is changing the lane and the situation where the target vehicle 2 is changing the direction leading to the reverse running can be appropriately made different. The estimated travel distance Le changes according to the vehicle speed V and generally becomes shorter as the vehicle speed V becomes lower. Therefore, the first determination distance Ld, which is set to a distance corresponding to the estimated travel distance Le, is set to be shorter as the vehicle speed V becomes lower. In this way, when the first determination distance Ld is a variable value that changes according to the vehicle speed V, the determination unit 11 refers to, for example, a table that defines the relationship between the vehicle speed V and the first determination distance Ld, The first determination distance Ld corresponding to the vehicle speed V of the target vehicle 2 at the time of determination is acquired. The first determination distance Ld may be a fixed value instead of a variable value that changes according to the vehicle speed V. The first determination distance Ld can be set to 10 [m], for example.

As an example, the estimated travel distance Le can be the minimum value of the travel distance of the target vehicle 2 that is assumed during the lane change from the start of the lane change operation to the crossing of the boundary line between the lanes 93. .. In this case, by suppressing the first determination distance Ld set to a distance according to the estimated travel distance Le to be short, the change in the traveling direction due to the road shape is less likely to be included in the detected angle change amount θ. Therefore, it is possible to improve the determination accuracy.

As described above, in the present embodiment, by setting the first determination distance Ld to a distance according to the assumed traveling distance Le, the traveling direction of the target vehicle 2 detected while traveling the first determination distance Ld The angle change amount θ can be appropriately made different between the situation where the target vehicle 2 is changing lanes and the situation where the target vehicle 2 is changing the direction leading to reverse running. Then, in the present embodiment, the first angle is set to an angle according to the assumed maximum change amount θmax. That is, the first angle is set to the same value as the assumed maximum change amount θmax, or set to a value (corrected value) obtained by adjusting the assumed maximum change amount θmax. As a result, it is possible to set the first determination distance Ld and the first angle so that the second condition is difficult to be satisfied when the target vehicle 2 is changing lanes.

By the way, the maximum value of the angle change amount θ in the traveling direction of the target vehicle 2 during traveling a certain distance, which is assumed when a normal driving operation such as a lane change is performed, becomes a low vehicle speed V. Tends to grow according to. In view of this point, it is preferable that the first angle is set to increase stepwise or continuously as the vehicle speed V decreases. In the present embodiment, as described above, the first angle is set to the angle corresponding to the assumed maximum change amount θmax. Then, the assumed maximum change amount θmax changes according to the vehicle speed V, and generally increases as the vehicle speed V decreases. Therefore, by setting the first angle to an angle corresponding to the assumed maximum change amount θmax, the first angle is set to increase as the vehicle speed V decreases. In this way, when the first angle is a variable value that changes according to the vehicle speed V, the determination unit 11 refers to, for example, a table that defines the relationship between the vehicle speed V and the first angle, and determines the target at the time of determination. The first angle corresponding to the vehicle speed V of the vehicle 2 is acquired. As an example of setting the first angle so as to increase stepwise as the vehicle speed V decreases, when the vehicle speed V is less than 20 [km/h], the first angle is set to 35 degrees, When the vehicle speed V is 20 [km/h] or more, the first angle can be set to 25 degrees. Note that the first angle may be a fixed value instead of a variable value that changes according to the vehicle speed V.

As described above, in the present embodiment, the first angle is set to the angle corresponding to the assumed maximum change amount θmax, and the first determination distance Ld is set to the distance corresponding to the assumed travel distance Le. The estimated maximum change amount θmax and the estimated traveling distance Le, which serve as a reference for setting the first angle and the first determination distance Ld, can be derived by simulation as described below.

As described above with reference to FIG. 6, in the situation where the target vehicle 2 makes a lane change, the steering angle is from zero to one turning direction side from the start of the lane change operation to the end of the lane change operation. After that, the steering device 5 is operated so that the steering angle decreases and returns to zero, and then the steering angle increases from zero to the other turning direction side and then decreases and returns to zero. Then, when such a lane change operation is performed so that it can be completed in the shortest time within the range assumed when the target vehicle 2 is traveling (that is, when the steepest lane change operation is performed), The traveling direction of the target vehicle 2 when crossing the boundary line between the lanes 93 with respect to the traveling direction of the target vehicle 2 before the start of the change operation (the traveling direction of the target vehicle 2 at time T21 in FIG. 6) (time in FIG. 6). The angle change amount θ in the traveling direction of the target vehicle 2 at T22 is the assumed maximum change amount θmax.

The time change of the yaw rate Y in the situation where the target vehicle 2 changes the lane so as to be completed in the shortest time is as follows. Can be derived by simulation based on the maximum value of the steering angular velocity that is supposed to be input to the steering device 5, the vehicle speed V, and the characteristics of the target vehicle 2. It should be noted that the reverse running determination system 1 determines whether or not the target vehicle 2 may run in reverse on the condition that the target vehicle 2 is traveling on a motorway (highway, urban highway, etc.). In some cases, the lane width X may be a fixed value (for example, a general lane width X of a motorway). In addition, the maximum value of the steering angular velocity that is supposed to be input to the steering device 5 is a variable value that changes according to the driver even if it is a fixed value assuming a general driver (for example, The value may be set by learning for each driver). Further, the characteristics of the target vehicle 2 include, for example, at least one of the steering characteristics of the target vehicle 2 and the turning characteristics of the target vehicle 2. The steering characteristic of the target vehicle 2 is, for example, a characteristic that represents the relationship between the input to the steering device 5 (for example, the steering wheel operation angle) and the steering angle of the steered wheels (here, the front wheels). The turning characteristic of the target vehicle 2 is, for example, a characteristic that represents the relationship between the steering angle of the steered wheels (here, the front wheels) and the traveling direction (direction) of the target vehicle 2, and the length of the wheel base of the target vehicle 2 is set. It changes according to the size of the minimum turning radius.

By time-integrating the yaw rate Y derived as a function of the time t as described above, the traveling direction (direction) of the target vehicle 2 at each time point during the lane change can be derived. The traveling direction of the target vehicle 2 at each time point is represented by a function of time t, and is represented by θ(t) here. Then, the amount of movement in the lateral direction (road width direction) from the start of the lane change operation at each time point during the lane change is derived by time integration of V×sin θ(t) with the vehicle speed as V. be able to. If the target vehicle 2 is located in the center of the lane 93 at the start of the lane change operation like the target vehicle 2 at time T21 in FIG. 6, the time integrated value of V×sin θ(t) is the lane width X. The time T (time T22 in FIG. 6) that is half the value of the time becomes the time when the target vehicle 2 crosses the boundary line between the lanes 93. Therefore, the value of θ(t) at this time T can be derived as the assumed maximum change amount θmax. Further, a value obtained by multiplying the time from the start of the lane change operation to the time T (time from time T21 to time T22 in FIG. 6) by the vehicle speed V can be derived as the estimated travel distance Le. The estimated mileage Le thus derived is the minimum value of the mileage of the target vehicle 2 assumed during the lane change from the start of the lane change operation to the crossing of the boundary line between the lanes 93. It

As described above, in the present embodiment, the estimated maximum change amount θmax and the estimated traveling distance Le are the lane width X and the steering angular velocity that is assumed to be input to the steering device 5 of the target vehicle 2 during the lane change. Is set based on the maximum value of the vehicle speed V, the vehicle speed V, and the characteristics of the target vehicle 2. Since the assumed maximum change amount θmax and the assumed travel distance Le change not only according to the vehicle speed V but also according to the lane width X, at least one of the first angle and the first determination distance Ld is set to the lane width. It can be set to a different value depending on X. When the first angle is a variable value that changes according to the lane width X, the determination unit 11 refers to a table that defines the relationship between the lane width X and the first angle, and the target vehicle 2 travels at the time of determination. The first angle is acquired according to the lane width X of the lane 93 that is open. When the first determination distance Ld is a variable value that changes according to the lane width X, the determination unit 11 refers to a table that defines the relationship between the lane width X and the first determination distance Ld, and determines at the time of determination. The first determination distance Ld corresponding to the lane width X of the lane 93 in which the target vehicle 2 is traveling is acquired.

Hereinafter, with reference to FIG. 3, a processing procedure of the reverse running determination process executed in the reverse running determining system 1 of the present embodiment will be described. Each step described below is executed by an arithmetic processing unit (computer) included in the reverse running determination system 1.

The control unit 10 acquires the detection data from the information acquisition unit 20 (step #01). When the vehicle speed V is equal to or higher than the first determination vehicle speed (step #02: Yes, step #03: Yes), the determination unit 11 determines whether the first condition is satisfied (step # #). 04). In this determination, the predicted turning radius R acquired by the turning radius acquisition unit 12 based on the detection data acquired in step #01 is used. Then, when the first condition is satisfied (when the first condition is satisfied) (step #04: Yes), the determination unit 11 determines that the target vehicle 2 may run backward (step #04). #05), the warning processing unit 14 performs warning processing (step #06). On the other hand, when the first condition is not satisfied (when the first condition is not satisfied) (step #04: No), the process ends, and the processes from step #01 are executed again.

When the vehicle speed V is less than the first determination vehicle speed and equal to or more than the second determination vehicle speed (step #02: Yes, step #03: No), the determination unit 11 determines whether the first condition and the second condition are satisfied. It is determined whether both are established (step #07). In this determination, the predicted turning radius R acquired by the turning radius acquisition unit 12 based on the detection data acquired in step #01 and the angle change amount acquisition unit 16 acquired by the angle change amount acquisition unit 16 based on the detection data acquired in step #01. One angle change amount is used. When both the first condition and the second condition are satisfied (when both the first condition and the second condition are satisfied) (step #07: Yes), the determination unit 11 determines that the target vehicle 2 is It is determined that there is a possibility of reverse running (step #05), and the warning processing unit 14 performs warning processing (step #06). On the other hand, when at least one of the first condition and the second condition is not satisfied (when at least one of the first condition and the second condition is not satisfied) (step #07: No), the process ends and step #01 The process from is executed again.

When the vehicle speed V is lower than the second determination vehicle speed (step #02: No), the determination unit 11 determines whether or not the third condition is satisfied (step #08). In this determination, the second angle change amount acquired by the angle change amount acquisition unit 16 based on the detection data acquired in step #01 is used. Then, when the third condition is satisfied (when the third condition is satisfied) (step #08: Yes), the determination unit 11 determines that the target vehicle 2 may reverse (step S08). #05), the warning processing unit 14 performs warning processing (step #06). On the other hand, when the third condition is not satisfied (when the third condition is not satisfied) (step #08: No), the process ends, and the process from step #01 is executed again.

Here, when the first condition is not satisfied in the process of step #04 (step #04: No), or when at least one of the first condition and the second condition is not satisfied in the process of step #07 (step #07). : No), the case where the process is terminated has been described as an example, but when the first condition is not satisfied in the process of step #04 (step #04: No), the process proceeds to step #08, When at least one of the first condition and the second condition is not satisfied in the process of #07 (step #07: No), the process may proceed to step #08. In this case, it is possible to suppress detection omission in a situation in which the target vehicle 2 may reversely run. Further, the processing procedure (step #02 and step #03) for changing the determination condition based on the vehicle speed V in FIG. 3 is an example, and it is a vehicle speed range equal to or higher than the first determination vehicle speed and less than the first determination vehicle speed. The processing procedure for determining which of the vehicle speed range the vehicle speed V is equal to or higher than the second determination vehicle speed and the vehicle speed range that is less than the second determination vehicle speed is not limited to the procedure shown in FIG.

Although details are omitted, conditions for determining whether or not the target vehicle 2 may run in reverse can be set. For example, the target vehicle 2 is traveling on a motorway, the target vehicle 2 is traveling on a one-way road 90, the target vehicle 2 is traveling on a road 90 having a median strip, The reverse running determination system 1 determines whether or not the target vehicle 2 may run in reverse on the condition that the target vehicle 2 is running in a place without an intersection (a place away from the intersection). It can be configured to.

[Other Embodiments]
Next, another embodiment of the reverse running determination system will be described.

(1) In the above-described embodiment, the determination unit 11 determines that the second angle change amount is equal to or greater than the second angle as the third condition, and when the vehicle speed V is less than the second determination vehicle speed, the first condition is satisfied. The configuration has been described as an example in which it is determined that the target vehicle 2 may run in reverse on the condition that the third condition is satisfied instead of satisfying both the first condition and the second condition. However, the third condition is not limited to such a configuration, and may be a condition different from that of the above-described embodiment. For example, the intersection angle of the traveling direction of the target vehicle 2 with respect to the extending direction of the road 90 (lane 93) on which the target vehicle 2 is traveling is equal to or greater than a specified angle (for example, the second angle in the above-described embodiment). This can be the third condition. Further, the determination unit 11 may be configured not to perform the determination based on the third condition. Specifically, when the vehicle speed V is less than the first determination vehicle speed, the determination unit 11 determines whether the vehicle speed V is less than the second determination vehicle speed, both the first condition and the second condition. It is possible to adopt a configuration in which it is determined that there is a possibility that the target vehicle 2 may run in reverse on the condition that is satisfied. Alternatively, the determination unit 11 may be configured not to perform the determination of the possibility that the target vehicle 2 runs in the reverse direction when the vehicle speed V is lower than the second determination vehicle speed.

(2) In the above-described embodiment, when the vehicle speed V is equal to or higher than the first determination vehicle speed, the determination unit 11 may cause the target vehicle 2 to run backward only on the condition that the first condition is satisfied. The configuration that determines that there is is described as an example. However, the determination unit 11 is not limited to such a configuration, and it is possible that the target vehicle 2 runs in reverse on the condition that the first condition is satisfied and that another condition is satisfied. It can also be configured to determine that there is. For example, the determination unit 11 repeatedly acquires the predicted turning radius R, and sets the condition that the first condition is satisfied, and that the predicted turning radius R that is equal to or less than the radius threshold value is continuously acquired a set number of times or more. As a further condition, a configuration may be adopted in which it is determined that the target vehicle 2 may run in reverse. The set number of times can be set to a number within the range of 5 to 10 times, for example.

Similarly, in the above embodiment, the determination unit 11 determines that the vehicle speed V is less than the first determination vehicle speed (specifically, the vehicle speed V is less than the first determination vehicle speed and equal to or more than the second determination vehicle speed). ) Has been described as an example of the configuration in which it is determined that the target vehicle 2 may run in reverse on the condition that both the first condition and the second condition are satisfied. It is also possible to adopt a configuration in which both the first condition and the second condition are satisfied, and further, another condition is determined to determine that the target vehicle 2 may run in reverse. For example, it is possible to set that the predicted turning radius R that is equal to or less than the radius threshold value is continuously acquired the set number of times or more, as another condition.

(3) In the above-described embodiment, when the vehicle speed V is less than the second determination vehicle speed, the determination unit 11 may cause the target vehicle 2 to run backward only on the condition that the third condition is satisfied. The configuration in which it is determined that there is is described as an example. However, the determination unit 11 is not limited to such a configuration, and it is possible that the target vehicle 2 runs in reverse on the condition that the third condition is satisfied and that another condition is satisfied. It can also be configured to determine that there is. For example, the determination unit 11 sets the condition that the third condition is satisfied, and the turning radius (estimated turning radius) derived based on the angle change amount θ in the traveling direction of the target vehicle 2 is a prescribed threshold value ( It is possible to adopt a configuration in which it is determined that the target vehicle 2 is likely to run in reverse on the condition that it is equal to or less than the second radius threshold). Note that this estimated turning radius is based on the angle change amount θ in the traveling direction and the traveling distance L of the target vehicle 2 while the traveling direction changes by the angle variation amount θ. It can be derived by dividing by the change amount θ. This second radius threshold can be set, for example, in the same manner as the radius threshold (first radius threshold) in the above embodiment.

(4) In the above embodiment, the reverse running determination system 1 includes the road width information acquisition unit 13 that acquires road width information indicating the road width W of the road 90 on which the target vehicle 2 is traveling, and the radius threshold is The configuration in which the value that is half the road width W represented by the road width information is set as a reference has been described as an example. That is, in the above embodiment, the radius threshold value is variably set according to the road width W of the road 90 on which the target vehicle 2 is traveling. However, the radius threshold value may be a fixed value without being limited to such a configuration. For example, the road 90 to be determined by the determination unit 11 is the target road 91, the maximum value of the road widths W of all the target roads 91 is the maximum road width, and the radius threshold is half the maximum road width. The value may be set as a reference. That is, in this case, the radius threshold is a value that is set with reference to a value that is half the maximum road width. The maximum road width is, for example, the road width W (for example, about 20 [m]) at a point where two lanes 93 (merging lane 93a) merge with a road 92 (main road) having four lanes 93. To be done. Further, the target road 91 can be limited to, for example, an automobile exclusive road.

(5) In the above-described embodiment, the radius threshold is set based on the road width W, specifically, the radius threshold is set based on a half of the road width W as a reference. did. However, without being limited to such a configuration, for example, the radius threshold value is set based on the value of the road width W (the maximum road width in the example of the other embodiment (4) described above). You can also Further, the radius threshold value may be set not based on the road width W. For example, the radius threshold value may be set based on the minimum curvature radius of the curved road of each road 90. .

(6) In the above embodiment, the turning radius acquisition unit 12 acquires a value obtained by dividing the vehicle speed V by the yaw rate Y as the predicted turning radius R, that is, the turning radius acquisition unit 12 determines the vehicle speed V as the vehicle speed V. The configuration in which the predicted turning radius R is acquired based on only the yaw rate Y has been described as an example. However, the turning radius acquisition unit 12 is not limited to such a configuration, and based on the vehicle speed V and the yaw rate Y, another predicted index (for example, the steering angle of the steered wheels) based on the predicted turning radius. It may be configured to acquire R.

(7) In the above embodiment, the turning radius acquisition unit 12 has been described as an example in which the turning radius acquisition unit 12 acquires the predicted turning radius R based on the vehicle speed V and the yaw rate Y. However, without being limited to such a configuration, the turning radius acquisition unit 12 acquires the predicted turning radius R without using one of the vehicle speed V and the yaw rate Y, and the turning radius acquisition unit 12 sets the vehicle speed V. Alternatively, the predicted turning radius R may be obtained without using both the yaw rate Y and the yaw rate Y. As the former configuration, for example, the turning radius acquisition unit 12 may be configured to acquire the predicted turning radius R based on the vehicle speed V and the steering angle of the steered wheels. In this case, the vehicle behavior of the target vehicle 2 detected in each specified cycle is the vehicle speed V and the steering angle of the steered wheels detected in each specified cycle. As the latter configuration, for example, the turning radius acquisition unit 12 may be configured to acquire the predicted turning radius R based on the change (transition) of the current position (coordinates) of the target vehicle 2. In this case, the vehicle behavior of the target vehicle 2 detected in each specified cycle is the current position of the target vehicle 2 detected in each specified cycle.

(8) In the above embodiment, the reverse running determination system 1 (control unit 10) includes the warning processing unit 14, and when it is determined that the target vehicle 2 may run backward, the warning processing unit 14 may The configuration for issuing a warning has been described as an example. However, without being limited to such a configuration, when the reverse running determination system 1 determines that the target vehicle 2 may run backward, the target vehicle 2 may be replaced by the warning process or in addition to the warning process. It is also possible to adopt a configuration in which the behavior of the vehicle 2 is controlled (for example, control for suppressing steering by the driver is performed).

(9) The allocation of each functional unit of the reverse running determination system 1 (control unit 10) shown in the above embodiment is merely an example, and a plurality of functional units may be combined or one functional unit may be further divided. It is also possible.

(10) It should be noted that the configurations disclosed in the above-described embodiments may be applied in combination with the configurations disclosed in the other embodiments as long as no contradiction occurs (of the embodiments described as other embodiments. (Including combinations) is also possible. Regarding other configurations, the embodiments disclosed in the present specification are merely examples in all respects. Therefore, various modifications can be appropriately made without departing from the spirit of the present disclosure.

[Outline of the above embodiment]
The outline of the reverse running determination system described above will be described below.

The reverse running determination system (1) determines whether the target vehicle (2) and the turning radius acquisition unit (12) that obtains the predicted turning radius (R) of the target vehicle (2) for each specified cycle may run in reverse. A determination unit (11) for determining, the first condition is that the predicted turning radius (R) is equal to or less than a specified radius threshold, and the above-mentioned determination is performed while traveling a specified first determination distance (Ld). The determination unit (11) sets the vehicle speed (V) of the target vehicle (2) under the second condition that the angle change amount (θ) of the target vehicle (2) in the traveling direction is equal to or greater than a specified first angle. Is equal to or higher than the prescribed first determination vehicle speed, it is determined that the target vehicle (2) may run in reverse on the condition that the first condition is satisfied, and the vehicle speed (V) Is less than the first determination vehicle speed, it is determined that the target vehicle (2) may run in reverse on the condition that both the first condition and the second condition are satisfied. ..

When the vehicle is traveling according to the traffic direction set on the road, the turning radius of the vehicle is basically larger than a certain value determined according to the shape of the road (for example, the road width). .. Therefore, when the turning radius of the vehicle is equal to or less than the certain value, it can be inferred that the direction change (U-turn or the like) leading to the reverse running may be performed. In view of this point, in the above configuration, based on at least whether the predicted turning radius (R) of the target vehicle (2) is equal to or less than the radius threshold (that is, at least whether the first condition is satisfied), It is determined whether or not the target vehicle (2) may run in reverse. Here, since the index to be compared with the radius threshold is the predicted turning radius (R) of the target vehicle (2) for each specified cycle, it is a relatively early stage before the traveling direction of the target vehicle (2) changes significantly. Thus, it is possible to determine whether or not the target vehicle (2) may reversely run. That is, it is possible to accelerate the timing of determining the possibility of the vehicle traveling in reverse.

By the way, the above-mentioned radius threshold is set so that it is possible to appropriately determine whether or not there is a possibility that the target vehicle (2) will run in reverse. It has been found that the predicted turning radius (R) can be equal to or less than the radius threshold even when a normal driving operation such as a lane change is performed when it is low. Based on such knowledge, in the above configuration, when the vehicle speed (V) is less than the first determination vehicle speed, the first determination is made as a condition for determining that the target vehicle (2) may reversely travel. The second condition that the angle change amount (θ) during traveling the distance (Ld) is equal to or larger than the first angle is included. As a result, it is possible to reduce the rate at which the target vehicle (2) is erroneously determined to be likely to run backward when a normal driving operation such as a lane change is performed. On the other hand, in the above configuration, when the vehicle speed (V) is equal to or higher than the first determination vehicle speed, the second condition is not included in the conditions for determining that the target vehicle (2) may reversely run. It is possible to determine whether or not there is a possibility that the target vehicle (2) will run in reverse at a stage before the angle change amount (θ) during traveling the first determination distance (Ld) becomes equal to or greater than the first angle. Has become.

As described above, according to the above configuration, it is possible to reduce the number of erroneous determinations and accelerate the determination timing of the possibility that the vehicle may run in reverse.

Here, it is preferable that the first angle is set to increase stepwise or continuously as the vehicle speed (V) decreases.

According to the above configuration, the maximum value of the angle change amount (θ) during traveling of the first determination distance (Ld), which is assumed when the normal driving operation is performed, is the vehicle speed (V). The first angle can be appropriately set in consideration of the tendency that the value becomes larger as the value becomes lower. Specifically, by setting the first angle larger than the maximum value of the angle change amount (θ), erroneous determination can be suppressed, and the difference between the maximum value of the angle change amount (θ) and the maximum value can be reduced. By setting the first angle so that it does not become too large, it is possible to accelerate the determination timing of the possibility that the vehicle may run in reverse.

Further, the maximum value of the angle change amount (θ) in the traveling direction of the target vehicle (2) that is assumed during the lane change operation before the start of the lane change operation is set as the assumed maximum change amount (θmax). It is preferable that one angle is set to an angle according to the assumed maximum change amount (θmax).

According to this configuration, even if a sudden lane change operation is performed, the angle change amount (θ) during traveling the first determination distance (Ld) does not exceed the first angle, One angle can be set. Therefore, it is possible to suppress erroneous determination due to a change in the traveling direction of the target vehicle (2) due to the lane change, regardless of the degree of lane change operation.

In the configuration in which the first angle is set to the angle corresponding to the assumed maximum change amount (θmax) as described above, the assumed maximum change amount (θmax) is calculated based on the lane in which the target vehicle (2) is traveling ( 93) width (X), the maximum value of the steering angular velocity that is expected to be input to the steering device (5) of the target vehicle (2) during the lane change, and the vehicle speed (V). , And is preferably set based on the characteristics of the target vehicle (2).

It is considered that the amount of angle change (θ) in the traveling direction of the target vehicle (2) before the start of the lane change operation becomes maximum, for example, when the target vehicle (2) crosses the boundary line with the adjacent lane (93). be able to. When considered in this way, the above-mentioned assumed maximum change is based on the maximum value of the crossing angle with respect to the boundary line in the traveling direction of the target vehicle (2), which is assumed when straddling the boundary line with the adjacent lane (93). The quantity (θmax) can be derived. According to the configuration, the maximum value of the intersection angle with respect to the boundary line in the traveling direction of the target vehicle (2) is derived based on the various parameters described above, and the assumed maximum change amount (θmax) is appropriately set. You can

In the reverse running determination system (1) of each of the above configurations, the first determination distance (Ld) is a boundary line between the lanes (93), which is assumed during the lane change, after the lane change operation is started. It is preferable to set the distance according to the traveling distance (Le) of the target vehicle (2) until the vehicle crosses over.

In the situation where the target vehicle (2) changes lanes, it is generally expected that the speed of change in the traveling direction of the target vehicle (2) will be a value close to zero when crossing the boundary line between the lanes (93). . On the other hand, in a situation where the target vehicle (2) makes a direction change (U-turn, etc.) that leads to reverse running, the changing speed in the traveling direction of the target vehicle (2) also occurs when crossing the boundary line between the lanes (93). It is generally expected to maintain the same value as before. Therefore, as in the above configuration, by setting the first determination distance (Ld) to a distance that corresponds to the traveling distance (Le) of the target vehicle (2) up to crossing the boundary line between the lanes (93). , The angle change amount (θ) detected while traveling the first determination distance (Ld), the situation in which the target vehicle (2) is changing lanes and the direction change in which the target vehicle (2) leads to reverse running. The situation can be different depending on the situation. As a result, it is easy to realize a configuration in which the second condition is difficult to be satisfied when the target vehicle (2) is changing lanes.

The determination unit (the third condition is that the angle change amount (θ) in the traveling direction of the target vehicle (2) while traveling the specified second determination distance is equal to or greater than the specified second angle. 11), when the vehicle speed (V) is less than a prescribed second determination vehicle speed that is smaller than the first determination vehicle speed, the first condition and the second condition are both satisfied and It is preferable to determine that the target vehicle (2) may run in reverse on the condition that the third condition is satisfied.

According to this configuration, when the vehicle speed (V) is less than the second determination vehicle speed that is less than the first determination vehicle speed, the condition that determines that the target vehicle (2) may run in reverse includes the first condition. The absence of the above makes it possible to appropriately determine whether or not there is a possibility that the target vehicle (2) will run in reverse, based on whether or not the third condition is satisfied, while simplifying the determination configuration.

The reverse running determination system according to the present disclosure may have at least one of the effects described above.

The various technical features of the reverse running determination system described above are also applicable to a reverse run determining method and a reverse run determining program, and such a method and program, and a storage medium storing such a program. (Eg, optical disks, flash memory, etc.) are also disclosed herein. For example, a reverse run determination method can include steps with the features of the reverse run determination system described above. Further, the reverse running determination program can cause a computer to realize the function having the features of the reverse running determination system described above. As a matter of course, these reverse run determination method and reverse run determination program can also achieve the operational effects of the above-described reverse run determination system. Furthermore, it is also possible to incorporate various additional features exemplified as a suitable aspect of the reverse run determination system into these reverse run determination methods and reverse run determination programs, and the method and the program have respective additional features. Corresponding effects can also be achieved.

1: Reverse running determination system 2: Target vehicle 5: Steering device 11: Determination unit 12: Turning radius acquisition unit 93: Lane Ld: First determination distance R: Predicted turning radius V: Vehicle speed X: Lane width (lane width)
θ: Angle change amount θmax: Assumed maximum change amount

Claims (8)

A turning radius acquisition unit that acquires the predicted turning radius of the target vehicle for each specified cycle,
A determination unit that determines the possibility that the target vehicle will run in reverse,
The first condition is that the predicted turning radius is equal to or less than a prescribed radius threshold value, and the amount of change in the traveling direction of the target vehicle during traveling the prescribed first determination distance is equal to or greater than the prescribed first angle. That is the second condition,
When the vehicle speed of the target vehicle is equal to or higher than the prescribed first determination vehicle speed, the determination unit determines that the target vehicle may run in reverse on the condition that the first condition is satisfied. However, when the vehicle speed is less than the first determination vehicle speed, it is determined that the target vehicle may run in reverse on the condition that both the first condition and the second condition are satisfied. Yes, a reverse run determination system. The reverse running determination system according to claim 1, wherein the first angle is set to increase stepwise or continuously as the vehicle speed decreases. Assuming the maximum change amount of the angle in the traveling direction of the target vehicle before the start of the lane change operation, which is assumed during the lane change,
The reverse run determination system according to claim 1 or 2, wherein the first angle is set to an angle corresponding to the assumed maximum change amount. The assumed maximum change amount is the width of the lane in which the target vehicle is traveling, the maximum value of the steering angular velocity that is expected to be input to the steering device of the target vehicle during the lane change, and the vehicle speed. The reverse running determination system according to claim 3, which is set based on a characteristic of the target vehicle. The first determination distance is set to a distance that is assumed during a lane change and that corresponds to a traveling distance of the target vehicle from when the lane change operation is started to when a lane boundary line is crossed. The reverse run determination system according to any one of 1 to 4. The third condition is that the amount of change in angle in the traveling direction of the target vehicle while traveling the prescribed second determination distance is equal to or greater than the prescribed second angle,
When the vehicle speed is less than a prescribed second determination vehicle speed that is smaller than the first determination vehicle speed, the determination unit replaces that the first condition and the second condition are both satisfied, and the third condition is satisfied. The reverse running determination system according to any one of claims 1 to 5, which determines that the target vehicle may run in reverse on the condition that a condition is satisfied. A turning radius acquisition step of acquiring a predicted turning radius of the target vehicle for each prescribed cycle,
A determination step of determining the possibility that the target vehicle will run in reverse,
The first condition is that the predicted turning radius is equal to or less than a prescribed radius threshold value, and the amount of change in the traveling direction of the target vehicle during traveling the prescribed first determination distance is equal to or greater than the prescribed first angle. That is the second condition,
In the determination step, if the vehicle speed of the target vehicle is equal to or higher than a prescribed first determination vehicle speed, it is determined that the target vehicle may run in reverse on the condition that the first condition is satisfied. However, when the vehicle speed is less than the first determination vehicle speed, it is determined that the target vehicle may run in reverse on the condition that both the first condition and the second condition are satisfied. Yes, the reverse run determination method. A turning radius acquisition function that acquires the predicted turning radius of the target vehicle for each specified cycle,
A determination function for determining the possibility that the target vehicle will run in reverse,
The first condition is that the predicted turning radius is equal to or less than a prescribed radius threshold value, and the amount of change in the traveling direction of the target vehicle during traveling the prescribed first determination distance is equal to or greater than the prescribed first angle. That is the second condition,
In the determination function, when the vehicle speed of the target vehicle is equal to or higher than the prescribed first determination vehicle speed, it is determined that the target vehicle may run in reverse on the condition that the first condition is satisfied. However, when the vehicle speed is less than the first determination vehicle speed, it is determined that the target vehicle may run in reverse on the condition that both the first condition and the second condition are satisfied. Yes, a reverse run determination program.

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