JP6712851B2 - Monitoring device and monitoring method of monitoring device - Google Patents

Description

The present invention relates to a monitoring method for monitoring device and the monitoring device.

In the technique disclosed in Patent Document 1, a radar is used as a distance measuring unit to detect a distance and a direction with respect to a target, and then coordinate conversion is performed to map the distance and the direction to an orthogonal coordinate space to calculate a coordinate value, When a target exists within a predetermined warning area centered on the own vehicle, an alarm is issued to alert the driver. Further, it has means for detecting that the traveling path of the own vehicle is curved, and by using the curvature of the curve to calculate the coordinate value of the orthogonal coordinate space, the target is located in the alarm area located in the predicted course of the own vehicle. It is judged whether it exists.

JP, 2003-215241, A

However, the technique disclosed in Patent Document 1 has a problem that the possibility of collision cannot be accurately determined because the determination is performed using only the position of the target.

It is an object of the present invention to provide a monitoring device and a monitoring method of the monitoring device that can accurately determine the possibility of a collision with a following vehicle when changing lanes.

In order to solve the above-mentioned problems, the present invention is a monitoring device for monitoring the situation around a vehicle, and when the vehicle is traveling on a curved road, it is adjacent to the lane on which the vehicle on the curved road is traveling. Setting means for setting a detection area corresponding to a lane shape for detecting another vehicle traveling behind the lane, which is based on polar coordinates with the center of rotation of the own vehicle as an origin, and the setting means set by the setting means. Reference is made to detection means for detecting another vehicle traveling in the detection area, detection means for detecting the position and speed of the other vehicle detected by the detection means, and position and speed of the other vehicle detected by the detection means. Determining means for determining the possibility of a collision when the host vehicle changes lanes, and the setting means expands or contracts the length behind the detection area according to the curvature of the curved road. In addition, when the curvature of the curved road is larger than a predetermined curvature, the detection area is shortened.

Further, according to the configuration as this, it is possible to use polar coordinates, to accurately determine the possibility of collision with other vehicles.

Further, in the present invention, the detection means detects the position and speed of the other vehicle based on the Cartesian coordinates, and the determination means determines that the own vehicle is based on the relationship between the other vehicle and the own vehicle in the Cartesian coordinates. The feature is that the possibility of a collision when the lane is changed is determined.
According to such a configuration, since it is possible to apply the collision algorithm on the straight road to make the judgment, the judgment algorithm can be simplified.

Further, in the present invention, the detection means detects the position and speed of the other vehicle based on polar coordinates, and the determination means changes the lane of the own vehicle based on the relationship between the other vehicle and the own vehicle in the polar coordinates. It is characterized in that the possibility of collision in the case of doing is determined.
With such a configuration, it is possible to accurately determine the possibility of a collision with another vehicle using polar coordinates.

Further, the present invention is characterized in that the setting means expands or contracts a rear length of the detection area according to the speed of the host vehicle.
With such a configuration, it is possible to set an optimum detection area according to the speed of the host vehicle.

Further, the present invention is characterized in that the setting means shortens the detection area when the speed of the host vehicle is slower than a predetermined speed.
With such a configuration, it is possible to prevent an erroneous determination that the vehicle collides with another vehicle when turning at an intersection or the like.

Further, the present invention is, in a monitoring method of a monitoring device for monitoring the surroundings of a vehicle, when the vehicle is traveling on a curved road, the lane adjacent to the lane on which the vehicle travels on the curved road is A setting step of setting a detection area corresponding to a lane shape for detecting another vehicle traveling behind based on polar coordinates whose origin is the center of rotation of the host vehicle, and the detection area set in the setting step. By referring to the detection step of detecting another traveling vehicle, the detection step of detecting the position and speed of the other vehicle detected in the detection step, and the position and speed of the other vehicle detected in the detection step, A determination step of determining the possibility of a collision when the vehicle changes lanes, and the setting step expands or contracts the rear length of the detection area according to the curvature of the curved road, and The detection area is shortened when the curvature of the curved path is larger than a predetermined curvature.

According to the present invention, it is possible to provide a monitoring device and a monitoring method for a monitoring device capable of accurately determining the possibility of a collision with a following vehicle when changing lanes.

It is a figure which shows the structural example of the monitoring apparatus which concerns on 1st Embodiment of this invention. It is a figure for demonstrating operation|movement of 1st Embodiment shown in FIG. It is a figure for demonstrating operation|movement of 1st Embodiment shown in FIG. It is a figure for demonstrating operation|movement of 1st Embodiment shown in FIG. 6 is a flowchart illustrating an example of processing executed in the first embodiment illustrated in FIG. 1. It is a flow chart explaining an example of processing performed in a 2nd embodiment of the present invention. 9 is a flowchart illustrating an example of processing executed in the second embodiment. It is a figure for explaining operation of a modification embodiment.

Next, an embodiment of the present invention will be described.

(A) Description of Configuration of First Embodiment FIG. 1 is a diagram illustrating a configuration example of a monitoring device according to a first embodiment of the present invention. As shown in this figure, the monitoring device 10 mainly includes an other vehicle detection unit 11, a vehicle state detection unit 12, a calculation processing unit 13, a steering detection unit 14, a direction instruction detection unit 15, and a warning unit 16. It is an element.

Here, the other vehicle detection unit 11 is configured by, for example, a radar device or the like that radiates an electric wave to the other vehicle and detects the position, speed, and the like of the other vehicle from the reflected wave.

The host vehicle state detection unit 12 is composed of, for example, a vehicle speed sensor and a yaw axis sensor, detects the traveling state of the host vehicle, and notifies the arithmetic processing unit 13 of the detected traveling state.

Based on the information supplied from the other vehicle detection unit 11, the own vehicle state detection unit 12, the steering detection unit 14, and the direction instruction detection unit 15, the calculation processing unit 13 determines whether the own vehicle has changed lanes. It is determined whether or not there is a possibility that the following vehicle traveling in the lane adjacent to the lane in which the vehicle is traveling may collide with the host vehicle, and if it is determined that there is the possibility of collision, a warning is issued via the warning unit 16. Emit.

The warning unit 16 includes, for example, a speaker that emits a warning sound, a blinking LED (Light Emitting Diode), and the like, and generates a warning sound when the arithmetic processing unit 13 determines that there is a possibility of collision. Call attention to the driver.

(B) Description of Operation of First Embodiment Next, the operation of the first embodiment of the present invention will be described. As shown in FIG. 2, it is assumed that the host vehicle C1 is traveling in the central lane L0 of a curved road (curved road). In this case, the arithmetic processing unit 13 of the monitoring device 10 acquires the vehicle speed V of the host vehicle and the yaw rate Y from the output of the host vehicle state detection unit 12. Then, the radius gyration R and the rotation center coordinates (Xc, Yc) shown in FIG. 2 are obtained based on the following equations (1) to (3). Here, z indicates the distance from the center of the vehicle body of the host vehicle to the reference position for rotation, as shown in FIG.

R=V/Y (1)
Xc=0-R (2)
Yc=0-z (3)

When the rotation center coordinates (Xc, Yc) are calculated in this way, next, when the own vehicle changes lanes, it is determined whether or not there is a possibility of collision with another succeeding vehicle C2 (FIG. 3). The hatched area is a detection area). For example, θ is set so that the length of the detection region (arc length) is equal to or greater than a predetermined length (for example, 30 m). More specifically, in the example of FIG. 3, θ can be set so that the length of the detection area set on the right lane L2 is equal to or longer than a predetermined length. The length of the detection region may be constant regardless of the speed of the host vehicle, or may be changed depending on the speed. When changing the length according to the speed, make the length of the detection area longer in proportion to the speed, or shorten the length of the detection area if the speed is slower than the predetermined speed. May be. Alternatively, the length of the detection area may be expanded or contracted according to the curvature of the road, or the length of the detection area may be shortened when the curvature is larger than a predetermined curvature.

Next, using the following equations (4) to (7), the distance between the center of rotation and the line forming the detection area (see FIG. 3) is calculated. Here, W indicates the width of the host vehicle C1 (width in the direction orthogonal to the traveling direction of the vehicle), and Lttc indicates the length of a TTC (Time to Collision) line described later. Further, it is assumed that W is substantially equal to the width of the vehicle.

Da=|R|-(W/2)-Lttc (4)
Db=|R|−(W/2) (5)
Dc=|R|+(W/2) (6)
Dd=|R|+(W/2)+Lttc (7)

Next, the coordinates of the other vehicle C2 are converted into polar coordinates (rt, θt) whose origin is the center of rotation. More specifically, the Cartesian coordinate system whose origin is the Cartesian coordinate origin (X0, Y0) shown in FIG. 3 is replaced by the following equations (8) and (9). ). It should be noted that Xt and Yt represent coordinates of the other vehicle C2 viewed from the own vehicle C1, as shown in FIG.

Xt′=(X0−Xc)+Xt (8)
Yt'=(Y0-Yc)+Yt (9)

Next, using the following equations (10) and (11), (Xt', Yt') is converted into polar coordinates (rt, θt) with the center of rotation as the origin. Here, atan() is a function for obtaining the arctangent in parentheses.

rt ² =Xt′ ² +Yt′ ² (10)
θt=atan(Yt′/Xt′)×180/π (11)

In this way, when the setting of the detection area and the calculation of the coordinates of the other vehicle C2 are completed, it is determined whether or not the other vehicle C2 exists in the detection area. More specifically, as shown in FIG. 3, a detection area of a lane L1 having an angle θ and a width of Dc to Dd and a lane L2 having an angle θ and a width of Da to Db. The detection area is compared with the coordinates (rt, rθ) of the other vehicle C2 to determine whether the other vehicle C2 belongs to one of these two detection areas. If it belongs to any of these detection areas, the following processing is executed.

When the other vehicle C2 belongs to the detection area, first, the X coordinate and the Y coordinate of the other vehicle C2 are converted into orthogonal coordinates as shown in FIG. 4 by the following equations (12) and (13). The reason for converting to the orthogonal coordinate system is that an algorithm for determining the possibility of collision can be applied when traveling on a straight road.

X'=R-rt (12)
Y′=2π×rt×θt/360° (13)

Next, the velocities Vx' and Vy' (see FIG. 4) of the other vehicle C2 in the orthogonal coordinate system are calculated based on the equations (14) and (15).

Vx′=Vx×cos θt−Vy×sin θt (14)
Vy′=Vy×sin θt−Vy×cos θt (15)

Then, finally, using the X′, Y′, Vx′, and Vy′ obtained as described above, the TTC line crossing determination is executed in the same manner as the straight road, and when there is a possibility of crossing, When the lane is changed to the lane in which the other vehicle C2 is traveling, the arithmetic processing unit 13 issues a warning via the warning unit 16 to call the driver's attention. More specifically, the distance that the other vehicle C2 travels in the X′ direction during the time τ is Vx′×τ, and the other vehicle C2 stays within the detection area to satisfy Vx′×τ<rt-Dc. This is the case. Also, assuming that the time until the other vehicle C2 reaches the TTC line is T, T=Y'/Vy', and the intersection with the TTC line is when T<TTC set time. The TTC set time may be, for example, about 5 seconds. Therefore, when Vx′×τ<rt−Dc is satisfied and Y′/Vy′<TTC set time is satisfied, the arithmetic processing unit 13 determines that there is a possibility of collision and warns the warning unit 16 A warning is issued via, and in other cases, it is determined that there is no possibility of collision.

According to the above processing, when the host vehicle C1 is traveling on a curved road, a curved detection region corresponding to the curved road is set behind the adjacent lanes L1 and L2, and this detection is performed. Since the other vehicle C2 belonging to the region is detected and the possibility of collision when the own vehicle C1 changes lanes is determined using the position and speed of the other vehicle C2, the traveling situation of the other vehicle C2 is considered. Then, the possibility of collision can be accurately determined.

Further, in the above process, when it is determined that the other vehicle C2 belongs to the detection area, the positional relationship between the other vehicle C2 and the own vehicle C1 is converted into the orthogonal coordinate system shown in FIG. Since the existing algorithm for determining the possibility of collision on a straight road can be used, the manufacturing cost of the device can be reduced.

Details of the processing executed in the embodiment shown in FIG. 1 will be described below with reference to FIG. When the process of the flowchart shown in FIG. 5 is started, the following steps are executed.

In step S10, the arithmetic processing unit 13 refers to the output of the own vehicle state detection unit 12 to acquire the state of the own vehicle. For example, the arithmetic processing unit 13 acquires the yaw rate and the vehicle speed output from the own vehicle state detection unit 12.

In step S11, the arithmetic processing unit 13 refers to the yaw rate acquired in step S10, determines whether the host vehicle is traveling on a curved road, and determines that the vehicle is traveling on a curved road (step S11: Yes). ), the process proceeds to step S13, and otherwise (step S11: No), the process proceeds to step S12. For example, when the yaw rate is not 0, it is determined that the vehicle is traveling on a curved road and the process proceeds to step S13.

In step S12, the arithmetic processing unit 13 executes a straight road determination process for determining whether there is a possibility of collision with a following vehicle when the lane is changed while traveling on a straight road. More specifically, the arithmetic processing unit 13 sets a linear detection area corresponding to a straight road to the rear of an adjacent lane, and when another vehicle belongs to this detection area, the calculation processing unit 13 is set as shown in FIG. The intersection with the TTC line shown is determined, and if it intersects, it is determined that there is a possibility of collision. Then, as a result of the determination, when it is determined that there is a possibility of collision with the following vehicle when the lane is changed, the driver's intention to change the lane (for example, a direction instruction in the lane direction in which the following vehicle is traveling). When the container is operated), a warning is issued via the warning unit 16.

In step S13, the arithmetic processing unit 13 calculates the rotation center coordinates (Xc, Yc) of the vehicle. More specifically, the rotation center coordinates (Xc, Yc) of the host vehicle are calculated based on the equations (1) to (3) described above.

In step S14, the arithmetic processing unit 13 sets a detection area corresponding to a curved road as shown in FIG. 3 behind the adjacent lanes L1 and L2. More specifically, the detection area is set based on the equations (4) to (7) described above. As a result, the detection area is set as the hatched area in FIG.

In step S15, the arithmetic processing unit 13 determines whether or not another vehicle exists in the detection area set in step S14, and when it determines that another vehicle exists (step S15: Yes), the process proceeds to step S16. Otherwise (step S15: No), the process proceeds to step S21. More specifically, it is determined whether or not there is another vehicle calculated by the above-described equations (8) to (11) in the detection area set by the above-described equations (1) to (3). If yes, go to step S16.

In step S16, the arithmetic processing unit 13 converts the position of the other vehicle into the Cartesian coordinates shown in FIG. More specifically, the arithmetic processing unit 13 converts the position of the other vehicle into a rectangular coordinate system based on the above equations (12) and (13).

In step S17, the arithmetic processing unit 13 converts the speed of the other vehicle into the Cartesian coordinates shown in FIG. More specifically, the arithmetic processing unit 13 converts the speed of the other vehicle into rectangular coordinates based on the above-mentioned equations (14) and (15).

In step S18, the arithmetic processing unit 13 determines whether or not the other vehicle intersects the TTC line, and if it determines that the other vehicle intersects (step S18: Yes), the process proceeds to step S19, and otherwise (step S18). : No), the process proceeds to step S21. More specifically, it is determined whether or not the TTC line is crossed by using X′, Y′, Vx′, Vy′ obtained by the above processing.

In step S19, the arithmetic processing unit 13 determines whether or not the own vehicle changes lanes with respect to the lane in which another vehicle exists, and when it determines that the own vehicle changes lanes (step S19: Yes), the process proceeds to step S20. Otherwise (step S19: No), the process proceeds to step S21. More specifically, the arithmetic processing unit 13 refers to the output from the direction instruction detecting unit 15, determines that the lane is to be changed when the direction indicator is operated in the lane direction in which another vehicle is present, and proceeds to step S20. move on. Alternatively, the arithmetic processing unit 13 refers to the output from the steering detection unit 14, determines that the lane should be changed when the vehicle is steered in the lane direction in which another vehicle exists, and proceeds to step S20.

In step S20, the arithmetic processing unit 13 issues a warning via the warning unit 16 to alert the driver.

In step S21, the arithmetic processing unit 13 determines whether or not to repeat the process. If it is determined that the process is to be repeated (step S21: Yes), the process returns to step S10 and the same process as the above is repeated, In other cases (step S21: No), the process ends.

According to the above flowchart, the operation described above with reference to FIG. 1 can be realized.

(C) Description of Second Embodiment Next, a second embodiment of the present invention will be described. The configuration of the second embodiment is the same as that of the first embodiment shown in FIG. 1, but a part of the processing executed by the arithmetic processing unit 13 is different. Below, it demonstrates centering around a different part.

In the first embodiment, the position and speed of the other vehicle C2 are converted from polar coordinates to the orthogonal coordinates shown in FIG. 4 to determine the possibility of collision, but in the second embodiment, the determination is made using polar coordinates. I am trying. FIG. 6 is a diagram showing a case of making a determination using polar coordinates. In the second embodiment, the tangential velocity Vθ and the normal velocity Vr are calculated based on the following equations (16) and (17).

Vθ=r×dθ/dt (16)
Vr=dr/dt (17)

Next, it is determined whether or not the other vehicle C2 intersects with the TTC line based on the tangential velocity Vθ and the normal velocity Vr obtained by the equations (16) and (17). More specifically, since the distance that the other vehicle C2 moves in the tangential direction during the time τ is Vr×τ, the other vehicle C2 stays within the detection area when Vr×τ<rt-Dc is satisfied. is there.

Further, the time τ until the other vehicle C2 reaches the TTC line is expressed by the following equation (18).

τ=θ/(Vθ/r) (18)

Therefore, if τ<TTC set time, the other vehicle C2 may cross the TTC line.

From the above, when Vr×τ<rt−Dc and τ<TTC set time, the other vehicle C2 may cross the TTC line, so it is determined that there is a possibility of collision. .. Then, when the driver operates the turn signal to the side of the lane in which the other vehicle C2 is traveling, a warning is given via the warning unit 16 that there is a possibility of collision.

Next, detailed processing of the second embodiment will be described with reference to FIG. 7. Note that, in FIG. 7, portions corresponding to those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 7, compared with FIG. 5, the processes of steps S16 to S18 are replaced with steps S30 to S32. Since the other processes are similar to those in the case of FIG. 5, steps S30 to S32 will be mainly described.

In step S30, the arithmetic processing unit 13 calculates the tangential velocity of the other vehicle C2. More specifically, the arithmetic processing unit 13 calculates the tangential velocity Vθ based on the above equation (16).

In step S31, the arithmetic processing unit 13 calculates the normal velocity of the other vehicle C2. More specifically, the arithmetic processing unit 13 calculates the normal velocity Vr based on the above equation (17).

In step S32, the arithmetic processing unit 13 refers to the tangential velocity Vθ and the normal velocity Vr calculated in steps S30 and S31, determines whether or not the other vehicle C2 intersects the TTC line, and determines that the other vehicle C2 intersects. In the case (step S32: Yes), the process proceeds to step S19. In other cases (step S32: No), the process proceeds to step S21. More specifically, if Vr×τ<rt−Dc and τ<TTC setting time, the arithmetic processing unit 13 may cross the other vehicle C2 with the TTC line. After determining that there is a possibility of collision, the process proceeds to step S20.

As described above, according to the second embodiment of the present invention, an existing algorithm for determining a collision on a straight road cannot be used, but a more accurate collision determination is performed using a polar coordinate system. be able to.

(D) Description of Modified Embodiments Needless to say, the above embodiments are merely examples, and the present invention is not limited to the above cases. For example, in the above embodiment, when it is determined in step S11 of FIG. 5 that the host vehicle is traveling on a curved road, the processing from step S13 onward is immediately executed, but the vehicle travels on a curved road. The straight road determination process shown in step S12 may be executed until a predetermined time elapses after the determination is made. According to such a process, for example, as shown in FIG. 8, when the host vehicle C1 has just entered a curved road and the other vehicle C2 is traveling on a straight road, By making a determination based on the same situation as described above, it is possible to prevent an erroneous determination from occurring.

Further, in the flowchart shown in FIG. 5, the determination may be made based only on the state at that time, or the history of information in the past may be stored and the determination may be made based on this history. According to such a method, it is possible to prevent the erroneous determination from occurring even when the condition of the road changes suddenly (for example, in the condition shown in FIG. 8).

In each of the above embodiments, the case where the curvature of the curved road is constant has been described as an example, but the present invention can be applied even when the curvature changes in the middle. When the curvature changes, as described above, it is possible to judge by referring to the past history, or by using the moving average, it is possible to judge by using the average value of the changing curvature. May be.

10 Monitoring device 11 Other vehicle detection unit (detection means)
12 Own vehicle state detection unit 13 Calculation processing unit (setting unit, detection unit, determination unit)
14 Steering detection unit 15 Directional instruction detection unit 16 Warning unit

Claims (6)

In the monitoring device that monitors the situation around the vehicle,
When the vehicle is traveling on a curved road, the detection area corresponding to the lane shape for detecting other vehicles traveling behind the lane adjacent to the lane in which the vehicle of the curve path travels its own Setting means for setting based on polar coordinates with the origin of rotation of the vehicle as the origin ,
Detection means for detecting another vehicle traveling in the detection area set by the setting means,
Detection means for detecting the position and speed of the other vehicle detected by the detection means,
A determination unit that determines the possibility of a collision when the host vehicle changes lanes with reference to the position and speed of another vehicle detected by the detection unit,
The setting means expands or contracts the rear length of the detection region according to the curvature of the curved road, and shortens the detection region when the curvature of the curved road is larger than a predetermined curvature,
A monitoring device characterized by the above. The detection means detects the position and speed of another vehicle based on the orthogonal coordinates,
The determining means determines the possibility of a collision when the own vehicle changes lanes based on the relationship between the other vehicle and the own vehicle in the orthogonal coordinates.
The monitoring device according to claim 1 , wherein: The detection means detects the position and speed of another vehicle based on polar coordinates,
The determining means determines the possibility of a collision when the own vehicle changes lanes, based on the relationship between the other vehicle and the own vehicle in the polar coordinates.
The monitoring device according to claim 1 , wherein: The monitoring device according to any one of claims 1 to 3 , wherein the setting unit expands or contracts the length behind the detection region according to the speed of the host vehicle. The monitoring device according to claim 4 , wherein the setting unit shortens the detection area when the speed of the host vehicle is slower than a predetermined speed. In the monitoring method of the monitoring device for monitoring the situation around the vehicle,
When the vehicle is traveling on a curved road, the detection area corresponding to the lane shape for detecting other vehicles traveling behind the lane adjacent to the lane in which the vehicle of the curve path travels its own Setting step to set based on polar coordinates with the center of rotation of the vehicle as the origin ,
A detection step of detecting another vehicle traveling in the detection area set in the setting step,
A detection step of detecting the position and speed of the other vehicle detected in the detection step,
A determination step of determining the possibility of a collision when the own vehicle changes lanes with reference to the position and speed of another vehicle detected in the detection step,
The setting step expands or contracts the rear length of the detection region according to the curvature of the curved road, and shortens the detection region when the curvature of the curved road is larger than a predetermined curvature,
A method for monitoring a monitoring device, comprising:

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