JP6625152B2 - Driving support device and driving support method - Google Patents

Description

  The present invention relates to a driving support device that supports driving of a vehicle.

  As a conventional driving support device, for example, as disclosed in Patent Document 1, there is a traveling lane departure prevention device that controls activation and prohibition of an alarm according to the driver's consciousness level when the vehicle departs from the lane. The characteristic configuration and operation of this lane departure prevention device are as follows.

  The traveling lane detecting means detects the position of the traveling lane on the road ahead of the vehicle. Then, the traveling state detecting means detects the traveling state of the vehicle. After that, the possibility of departure from the traveling lane is determined from the traveling state of the vehicle and the position of the traveling lane detected by the departure possibility determining means. On the other hand, the consciousness level detecting means detects the consciousness level of the driver. Further, when it is determined that the possibility of the lane departure is large based on the determination result of the departure possibility determining unit, the alarm control unit determines whether the warning lane departure is in accordance with the driver's consciousness level detected by the consciousness level detecting unit. Controls activation and disabling of alarms. As described above, in the conventional driving support device, the camera recognizes the white line of the lane, and issues an alarm to the driver when the vehicle approaches the white line too much.

JP-A-6-171392

  In the conventional driving support device, the vehicle is driven based on the traveling lane detected by the traveling lane detecting means, and an alarm is issued when the vehicle and the traveling lane approach. However, even if an alarm is issued suddenly, there may be no time to respond.

  The present invention has been made in order to solve the above-described problem, and has as its object to provide a driving support device that issues a warning that can respond with a margin.

  A driving support device according to the present invention includes a lane detection unit that detects a traveling lane ahead of a vehicle, a vehicle control unit that causes the vehicle to travel so as to stay in the traveling lane, and a traveling road and traveling ahead of the vehicle. An object detection unit that detects an object around a road, a distance detection unit that detects a distance between the vehicle and the object, and a current lateral position of the vehicle in the traveling lane detected by the lane detection unit, An interval calculating unit that calculates an interval between the vehicle and the traveling lane based on a current lateral position of the vehicle based on the lane width of the traveling lane, and issues an alarm according to an instruction from the vehicle control unit. And a warning unit, wherein the vehicle control unit compares the distance with a first threshold, and when the distance falls below the first threshold, the warning is performed based on the interval. Of whether to emit The reference value is changed to increase the second threshold value, the interval calculation unit determines whether the interval is less than the second threshold value, the vehicle control unit, When the interval is smaller than the second threshold value, the alarm unit is controlled to issue the alarm.

  ADVANTAGE OF THE INVENTION According to the driving assistance device which concerns on this invention, it can respond to a warning with margin.

FIG. 1 is a block diagram showing an overall configuration of a vehicle equipped with a driving support device according to the present invention. It is a functional block diagram showing composition of a driving support device of an embodiment concerning the present invention. It is a flowchart explaining the driving assistance method in the driving assistance device of the embodiment according to the present invention. It is a figure explaining change of the road shoulder when there is a tunnel ahead. FIG. 9 is a diagram illustrating a second threshold value. It is a figure showing the hardware composition which realizes the driving support device of an embodiment concerning the present invention. It is a figure showing the hardware composition which realizes the driving support device of an embodiment concerning the present invention.

<Embodiment>
Hereinafter, an embodiment of a driving assistance device according to the present invention will be described with reference to FIGS.

<Apparatus configuration>
FIG. 1 is a block diagram showing the overall configuration of a vehicle 1 equipped with a driving support device according to the present invention. In FIG. 1, a steering system is mainly shown, and a drive system and the like are omitted.

  As shown in FIG. 1, a vehicle 1 has a steering motor / ECU (Electronic Control Unit) 4 attached to a steering wheel 3 that operates two front wheel tires 2, and based on a control signal from the driving support device 100, The steering motor / ECU 4 is configured to automatically steer the steering wheel 3.

  The driving assistance device 100 is also referred to as an ADAS (Advanced Driving Assistance Systems) -ECU, and has map data stored in the map data storage device 30, traveling lane information and an antenna obtained from the front camera 5 that images the front of the vehicle. A target steering angle that does not deviate from the traveling lane is calculated based on the current position information calculated by the satellite positioning device 20 based on positioning satellite signals received from the plurality of positioning satellites 6 via the receiver 7 and the steering motor. / ECU4.

  Each tire 2 is provided with a vehicle speed sensor 8, which measures the number of rotations of the tire 2 to calculate a vehicle speed and provides the calculated vehicle speed to the driving support device 100.

  The alarm 9 connected to the driving support device 100 warns the driver when the vehicle may deviate from the driving lane, and when the vehicle is approaching an object on or around the traveling road. Emits an alarm sound for

  The front camera 5 outputs information on the traveling lane (white line) obtained by imaging the front of the vehicle as camera information and inputs the information to the driving support device 100.

  The front camera 5 may use a monocular camera or a stereo camera. In addition, the present invention is not limited to the visible light camera, and an infrared camera may be used. The type of the camera may be changed according to the environment, or may be used in combination.

  The positioning satellites 6 are a plurality of satellites flying around the earth, such as a Global Navigation Satellite System (GNSS) and a quasi-zenith satellite, but only one is shown in FIG. 1 for convenience.

  The antenna / receiver 7 receives satellite signals from the plurality of positioning satellites 6, and the satellite positioning device 20 calculates the current position of the own vehicle (own vehicle position) based on the satellite signals, and outputs the current position to the driving support device 100.

  Although the vehicle speed sensor 8 is shown in FIG. 1 to calculate the vehicle speed by measuring the rotational speed of one tire, the present invention is not limited to this, and the average value of the rotational speeds of the four tires is used. The vehicle speed may be calculated from the average value of the rotation speed of the right wheel and the average value of the rotation speed of the left wheel.

  Next, the configuration of the driving support device 100 will be described using the functional block diagram shown in FIG. As shown in FIG. 1, the driving support device 100 includes a lane detecting unit 10, an object detecting unit 40, a distance detecting unit 50, an interval calculating unit 60, a vehicle control unit 70, a vehicle speed control unit 80, and an alarm unit 90.

  The lane detecting unit 10 detects the curvature of the traveling lane on the traveling road ahead of the vehicle and the current lateral position of the own vehicle in the traveling lane based on the camera information output from the front camera 5. A known method can be used for detecting the curvature of the lane and the current lateral position of the own vehicle by the front camera. For example, a video signal obtained by imaging the front with the front camera 5 is 2 Performs valued image processing and edge detection processing, detects the left and right white lines of the own vehicle by Hough transform or the like, obtains the relative position of the left and right white lines with respect to the own vehicle, and determines the current lateral position of the own vehicle, that is, the own vehicle. The distance from the center point to the left and right white lines is detected, and the curvature of the traveling lane is detected. The detected current lateral position of the host vehicle and the curvature of the traveling lane are output to the interval calculation unit 60 and the vehicle control unit 70. In addition, as a method of detecting a white line of a traveling lane, there is a method of using pattern matching for extracting a characteristic shape. However, any method may be used to detect the white line.

  Based on the satellite positioning position received by the satellite positioning device 20 and the map data stored in the map data storage device 30, the object detection unit 40 detects an object on the traveling road ahead of the current traveling position of the own vehicle and around the traveling road. Detect. Here, the objects on the traveling path and around the traveling path obtained based on the map data refer to structures and facilities where the distance between the vehicle and the object is short, such as the entrance and exit of a tunnel and a toll collection point. Shall be. By using map data, accurate information can be obtained. A method of obtaining the current traveling position from the satellite positioning position and the map data is a known technique, and is disclosed in, for example, Japanese Patent No. 6080998. In addition, if position information of irregular objects on the road, which cannot be obtained from map data, can be obtained through road information and communication with surrounding vehicles, this should also be treated as objects on the road and around the road. Can be.

  Instead of using map data, an object on the traveling road in front of the own vehicle and around the traveling road may be detected by performing pattern matching on image data in front of the own vehicle obtained from the front camera 5. Further, the distance to the object may be measured using a millimeter wave radar, LIDAR (Light Detection and Ranging), or the like.

  Further, the map data includes road curvature information that defines the degree of curvature of the road for each predetermined distance defined by the latitude and longitude coordinate data as road information. Therefore, if the current vehicle position (satellite positioning position) is known from the positioning satellite signal, the curvature of the traveling lane near the current vehicle position can be specified from the map data. The curvature of the traveling lane may be specified based on the satellite positioning position.

  The distance detection unit 50 detects a distance between the host vehicle and an object on the traveling road and around the traveling road. For example, by using the current vehicle position and the map data obtained by the positioning satellite signal, the vehicle position on the map can be determined. Detects distance from vehicle position. By using map data, accurate information can be obtained.

  The interval calculation unit 60 calculates an interval between the host vehicle and the traveling lane. That is, based on the current lateral position of the vehicle in the driving lane output from the lane detecting unit 10 and the lane width of the current driving lane obtained from the map data stored in the map data storage device 30, The distance between the host vehicle and the traveling lane is calculated based on the current lateral position. For example, assuming that the center of the lane width (lane width / 2) is the center of the road, by comparing the center of the road with the lateral position of the vehicle, it is possible to determine how far to the left or right and how much the vehicle is closer to the lane. The distance from the car can be calculated. If it is known from the current lateral position that the vehicle is at the center of the lane, the distance between the vehicle and the lane is the lane width / 2 on both the left and right sides. The calculated distance between the vehicle and the traveling lane is output to the vehicle control unit 70.

  The vehicle control unit 70 controls the own vehicle to stay in the running lane using the own vehicle position, the curvature of the running lane, and the current lateral position. That is, the lateral position control amount is obtained using the following equation (1).

Lateral position control amount = target lateral position (lane center)-current lateral position ... (1)
The target steering angle is obtained from the following equation (2) using the curvature of the traveling lane and the lateral position control amount, and the own vehicle is controlled so as to stay in the traveling lane.

Target steering angle = K1 × curvature of front lane + K2 × lateral position control amount (2)
K1 and K2 are parameters that are set in advance according to vehicle characteristics and the like. The calculated target steering angle is input to the steering motor / ECU 4. Expressions (1) and (2) will be further described later.

  The vehicle speed control unit 80 calculates a target vehicle speed calculated based on the vehicle speed information output from the vehicle control unit 70, and outputs the calculated target vehicle speed to the steering motor / ECU 4.

  The alarm unit 90 outputs an alarm signal to the alarm device 9 based on an alarm instruction output from the vehicle control unit 70.

<Operation>
Next, a driving support method in the driving support device 100 will be described with reference to a flowchart shown in FIG.

  When the vehicle or the in-vehicle system is activated and the driving support device 100 is activated, the application of the operation flow is started. First, the lane detecting unit 10 detects the traveling lane based on the camera information output from the front camera 5, The curvature of the traveling lane on the road ahead and the current lateral position of the host vehicle are detected (step S101).

  At this time, the object detection unit 40 detects whether or not there is an object on the traveling road ahead of the current traveling position and around the traveling road, and when the object is present, the distance detection unit 50 detects the presence of the object. The distance is detected (step S102). Here, the objects on and around the traveling road ahead refer to structures and facilities such as entrances and exits of tunnels and toll collection points. If there is no object on or near the traveling road ahead of the current traveling position, the process proceeds to step S105, but the route is not shown.

  Next, the vehicle control unit 70 determines whether or not the distance to the object detected by the distance detection unit 50 is less than a first threshold (Step S103). Then, when the value is lower than the first threshold value, the process proceeds to step S104, and otherwise, the process proceeds to step S105.

  Here, assuming that the distance to the object detected in step S102 is D_cal and the first threshold value is V1, the determination in step S103 is made based on whether or not the following expression (3) is satisfied.

D_cal-V1 <0 (3)
When the process proceeds to step S104, the vehicle control unit 70 changes the second threshold value, which is a criterion for determining whether or not the distance between the host vehicle and the traveling lane, issues an alarm, so as to increase the threshold value. Assuming that the second threshold value before the change is Y1 and the second threshold value after the change is Y2, the value is changed as in the following Expression (4).

Y1 <Y2 (4)
The reason why such a change is made will be described with reference to FIG. 4 taking as an example a case where an object on the front traveling road and around the traveling road is a tunnel. As shown in FIG. 4, before the host vehicle OV enters the tunnel TN, a road shoulder RS1 having a sufficient width is provided outside the traveling lane, but when entering the tunnel TN, the road shoulder RS2 becomes narrow. There are cases. In such a case, if the driver visually senses the inner wall of the tunnel nearby and is alerted suddenly, there is a possibility that excessive avoidance action may be taken. This is the same at toll collection points.

  Therefore, before entering these structures and facilities, the second threshold value for determining whether or not it is an interval at which a warning should be issued is increased so that a warning can be issued earlier. Increasing the second threshold value makes it easier to determine that an alarm should be issued.

  The determination of whether to increase the second threshold value based on the distance between the vehicle and the object is performed so that the second threshold value can be changed before entering the tunnel. It is.

  When traveling in a tunnel, as the width of the shoulder is reduced as described above, the margin between the traveling lane and the wall of the tunnel becomes relatively small, so when the tunnel is approaching forward By enabling the warning to be issued earlier, the vehicle can take an avoidance action such as moving the vehicle closer to the center of the lane with a margin.

  In addition, the point at which the second threshold value is changed from Y1 to Y2 may be a point where D_cal = 0 or a point before the point where D_cal = 0 (based on the own vehicle), based on Expression (3). (Close position). Note that the point where D_cal = 0 is a point where the own vehicle OV enters the tunnel TN based on FIG.

  When the position is set closer to the host vehicle by the distance V2 from the point of D_cal = 0, the distance D_sw from the host vehicle to the point where the second threshold value is changed to Y2 is represented by the following equation (5). You.

D_sw = D_cal-V2 (5)
In the above equation (5), it is assumed that the relationship between the distance V2 and the first threshold value V1 is V2 ≦ V1. As V2 becomes larger, more avoidance action becomes possible.

  In the present embodiment, when the second threshold value is increased in step S104, vehicle control unit 70 instructs vehicle speed control unit 80 to change the vehicle speed of the host vehicle to a preset vehicle speed. You may do it. By reducing the vehicle speed, it is possible to take evasive action with more margin. Here, as an example of the preset vehicle speed, a speed limit under the Road Traffic Law is given, and even if the road is curved if the speed limit is set according to the road, it is reasonable. Can respond.

  The vehicle control unit 70 calculates a target steering angle so that the vehicle travels along the traveling lane detected in step S101 (step S105). First, a deviation between the current lateral position of the vehicle detected by the lane detecting unit 10 and the target lateral position set by the vehicle control unit 70 is calculated as a lateral position control amount. Assuming that the current lateral position is L0, the target lateral position is Lt, and the lateral position control amount is ΔL, the lateral position control amount is expressed by the following equation (6).

ΔL = Lt−L0 (6)
Next, assuming that the curvature of the traveling lane ahead of the vehicle detected by the lane detector 10 is Curv and the target steering angle is θt, the target steering angle θt is represented by the following equation (7).

θt [deg] = K1 [deg · m] × Curv [1 / m] + K2 [deg / m] × ΔL [m] (7)
By performing the steering control of the own vehicle according to the target steering angle, the own vehicle can be caused to travel so as to stop in the traveling lane. In addition, when the own vehicle is traveling so as to stop in the traveling lane according to the target steering angle, and the own vehicle performs an operation that may deviate from the traveling lane, an alarm is issued from the alarm 9. (Lane departure warning) is issued.

  Note that step S105 may be executed at any timing after the traveling lane is detected in step S101, and may be executed concurrently with steps S102 to S104.

  The interval calculation unit 60 calculates an interval between the host vehicle and the travel lane, and determines whether the interval between the host vehicle and the travel lane is smaller than a second threshold value (step S106). In this case, classification is performed using the road width W of the current traveling position acquired from the map data stored in the map data storage device 30.

  That is, the case where the current lateral position L0 of the own vehicle is on the traveling lane side with respect to half the lane width (W / 2), and the case where the current lateral position L0 of the own vehicle is half the lane width (W / 2) or more. Divide if you are away from the lane.

  The former case is represented by the following equation (8), and the former case is represented by the following equation (9).

L0 <W / 2: L0 <Y1 (or L0 <Y2) (8)
W / 2 ≦ L0: W−Y1 <L0 (or W−Y2 <L0) (9)

  Here, the second threshold values Y1 and Y2 will be further described with reference to FIG. FIG. 5 shows a case in which the object on the traveling road in front and around the traveling road is the tunnel TN as in FIG. 4, and the host vehicle OV is traveling near the center line CL in the left lane of the two-lane road. However, since W−Y1> L0, Expression (9) is not established.

  Since the second threshold values Y1 and Y2 are threshold values used for determining whether or not the vehicle is approaching the white line of the traveling lane, the second threshold values are set symmetrically with respect to the left and right sides of the vehicle in the lane. In addition, since the road may be one lane when entering the tunnel, the same setting is made not only on the left side but also on the right side. This is the same for the toll collection lane.

  If the above equation (8) or (9) is established, the process proceeds to step S107. If the equation (8) or (9) is not established, it is determined that there is no need to issue a warning, and the series of processes ends. The following processing is repeated.

  When it is determined in step S106 that the distance between the host vehicle and the traveling lane is smaller than the second threshold value, the interval calculation unit 60 transmits the determination result to the vehicle control unit 70, and the vehicle control unit 70 The alarm unit 90 controls the alarm unit 90 to output an alarm signal to the alarm unit 9, and the alarm unit 9 issues an alarm to warn the driver that the vehicle has performed an operation that may deviate from the driving lane (step). S107).

  In step S107, an alarm is issued by an audible means such as a sound by the alarm device 9, but at the same time, a warning may be issued by a visual means such as blinking a warning light on a display such as an in-vehicle combination meter. By giving a visual warning together, the driver can be more reliably transmitted. Further, a visual means may be added to warn the driver that the vehicle is approaching an object on and around the traveling path in front of the vehicle.

  Further, in the present embodiment, the curvature of the traveling lane on the road ahead of the vehicle and the detection of the current lateral position of the own vehicle in the traveling lane are performed based on the camera information obtained by the front camera 5. The present invention is not limited to this, and the lane shape in front of the vehicle and the current lateral position may be detected by the satellite positioning system and the map data. A method for detecting the shape of the traveling lane ahead of the vehicle and the current lateral position using the satellite positioning system and the map data is a known technique.

  Note that each unit of the driving support device 100 according to the present embodiment can be configured using a computer, and is realized by the computer executing a program. That is, the driving support device 100 illustrated in FIG. 2 is realized by, for example, the processing circuit 100 illustrated in FIG. A processor such as a CPU and a DSP (Digital Signal Processor) is applied to the processing circuit 100, and functions of each unit are realized by executing a program stored in a storage device.

  Note that dedicated hardware may be applied to the processing circuit 100. When the processing circuit 100 is dedicated hardware, the processing circuit 100 includes, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. I do.

  FIG. 7 illustrates a hardware configuration when the driving support device 100 illustrated in FIG. 2 is configured using a processor. In this case, the function of each unit of the driving support device 100 is realized by a combination of software and the like (software, firmware, or software and firmware). Software and the like are described as programs and stored in the memory 112. The processor 111 functioning as the processing circuit 100 reads out and executes a program stored in the memory 112 (storage device) to realize the function of each unit.

  It should be noted that the present invention can appropriately modify and omit the embodiments within the scope of the invention.

  10 lane detector, 20 satellite positioning device, 30 map data storage device, 40 object detector, 50 distance detector, 60 interval calculator, 70 vehicle controller, 80 vehicle speed controller, 90 alarm unit.

Claims (10)

A lane detecting unit that detects a traveling lane in front of the vehicle,
A vehicle control unit that causes the vehicle to travel so as to stay in the traveling lane;
An object detection unit that detects an object on a traveling path in front of the vehicle and around the traveling path,
A distance detection unit that detects a distance between the vehicle and the object,
Based on the current lateral position of the vehicle and the lane width of the traveling lane in the traveling lane detected by the lane detection unit, based on the current lateral position of the vehicle, the vehicle and the traveling lane An interval calculator for calculating the interval of
An alarm unit that issues an alarm according to an instruction from the vehicle control unit,
The vehicle control unit includes:
Comparing the distance with a first threshold,
If the distance is less than the first threshold, change to increase the second threshold as a criterion of whether to issue the warning based on the interval,
The interval calculation unit,
Determining whether the interval is below the second threshold,
The vehicle control unit includes:
A driving support device that controls the alarm unit to issue the alarm when the interval is smaller than the second threshold value. The object detection unit,
The driving support device according to claim 1, wherein the object is detected using a current position of the vehicle obtained by a positioning satellite signal and map data. The distance detector,
The driving support device according to claim 1, wherein the distance between the vehicle and the object is detected using a current position of the vehicle obtained by a positioning satellite signal and map data. The vehicle control unit includes:
The driving support device according to claim 1, wherein when the second threshold value is increased, control is performed such that the vehicle speed of the vehicle is changed to a preset vehicle speed. The preset vehicle speed is:
The driving assistance device according to claim 4, wherein the driving assistance device is a speed limit under a road traffic law. The alarm unit,
The driving assistance device according to claim 1, wherein the alarm is issued by audible means and visual means. The object is
The driving assistance device according to claim 1, including facilities and structures on and around the traveling path. (A) detecting a traveling lane ahead of the vehicle;
(B) detecting objects on and around a traveling path in front of the vehicle;
(C) detecting a distance between the vehicle and the object;
(D) based on the current lateral position of the vehicle in the travel lane detected in the step (a) and the lane width of the travel lane, based on the current lateral position of the vehicle, Calculating the distance between the vehicle and the traveling lane;
(E) comparing the distance with a first threshold value;
(F) changing the second threshold value, which is a criterion for determining whether or not to issue an alarm, based on the interval when the distance falls below the first threshold value, to increase the threshold value; ,
(G) determining whether the interval is less than the second threshold;
(H) issuing the alarm when the interval is smaller than the second threshold value. (A) detecting a traveling lane ahead of the vehicle;
(B) detecting objects on and around a traveling path in front of the vehicle;
(C) detecting a distance between the vehicle and the object;
(D) Based on the steps (a), (b), and (c), when it is detected that the vehicle has approached the object, a criterion for issuing a warning when the vehicle approaches the traveling lane is determined. Changing to make it easier to issue an alarm. A lane detecting unit that detects a traveling lane in front of the vehicle,
A vehicle control unit that causes the vehicle to travel so as to stay in the traveling lane;
An object detection unit that detects an object on a traveling path in front of the vehicle and around the traveling path,
A distance detection unit that detects a distance between the vehicle and the object,
An alarm unit that issues an alarm according to an instruction from the vehicle control unit,
The vehicle control unit includes:
When the object detection unit detects that the vehicle has approached the object, the criterion for issuing an alarm when the vehicle approaches the traveling lane is changed to make it easier to issue an alarm from the alarm unit. Support device.

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