JP2019159979A - Drive support device and drive support method - Google Patents

Abstract

To provide a drive support device for issuing an alarm well in advance.SOLUTION: A drive support device comprises a lane detection unit, a vehicle control unit, an object detection unit, a distance detection unit, an interval calculation unit, and an alarm unit. The vehicle control unit compares a distance from an object in front of a vehicle on a driving lane or in the periphery of the driving lane detected by the object detection unit and a distance detection unit with a first threshold value. When the distance becomes smaller than the first threshold value, a second threshold value serving to be a criterion for determining whether an alarm is issued or not is changed to be larger based on an interval between the vehicle and a driving lane calculated by the interval calculating unit. The alarm section is controlled to issue an alarm when the interval between the vehicle and the driving lane is less than the second threshold.SELECTED DRAWING: Figure 2

Description

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

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

  The traveling lane detecting means detects the position of the traveling lane on the road in front of the vehicle. Then, the traveling state detecting means detects the traveling state of the vehicle. Thereafter, 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 departure from the driving lane is large based on the determination result in the departure possibility determination means, the alarm control means determines whether the warning generation means is in accordance with the driver's consciousness level detected by the consciousness level detection means. Controls alarm activation and deactivation. As described above, in the conventional driving support device, the camera recognizes the white line of the lane, and issues a warning to the driver when the vehicle is too close to the white line.

JP-A-6-171392

  In the conventional driving assistance 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 each other. However, even if a warning is issued suddenly, there may be no room for response.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a driving support device that issues an alarm that can be dealt with with a margin.

  A driving support apparatus according to the present invention includes a lane detecting unit that detects a traveling lane in front of a vehicle, a vehicle control unit that causes the vehicle to travel so as to remain in the traveling lane, and a traveling path and traveling in front 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 travel lane detected by the lane detection unit; Based on the lane width of the travel lane, based on the current lateral position of the vehicle, an interval calculation unit that calculates an interval between the vehicle and the travel lane, and an alarm according to an instruction from the vehicle control unit An alarm unit, wherein the vehicle control unit compares the distance with a first threshold value, and if the distance is less than the first threshold value, the alarm is based on the interval. Whether or not to issue The second threshold value is changed so as to increase, and the interval calculation unit determines whether or not the interval is below the second threshold value, and the vehicle control unit The alarm unit is controlled to issue the alarm when the interval is below the second threshold value.

  According to the driving support apparatus according to the present invention, it is possible to deal with an alarm with a margin.

1 is a block diagram showing an overall configuration of a vehicle equipped with a driving support apparatus according to the present invention. It is a functional block diagram which shows a structure of the driving assistance device of embodiment which concerns on this invention. It is a flowchart explaining the driving assistance method in the driving assistance apparatus of embodiment which concerns on this invention. It is a figure explaining the change of the road shoulder when there is a tunnel ahead. It is a figure explaining the 2nd threshold value. It is a figure which shows the hardware constitutions which implement | achieve the driving assistance apparatus of embodiment which concerns on this invention. It is a figure which shows the hardware constitutions which implement | achieve the driving assistance apparatus of embodiment which concerns on this invention.

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

<Device configuration>
FIG. 1 is a block diagram showing an overall configuration of a vehicle 1 equipped with a driving support apparatus 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 handle 3 that operates two tires 2 on the front wheels, and based on a control signal from the driving support device 100, The steering motor / ECU 4 is configured to automatically handle the steering wheel 3.

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

  Each tire 2 is provided with a vehicle speed sensor 8, which calculates the vehicle speed by measuring the number of rotations of the tire 2 and gives it to the driving support device 100.

  The alarm device 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 and around the driving road. A warning sound is emitted.

  The front camera 5 outputs information on a 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 be a monocular camera or a stereo camera. Further, the present invention is not limited to the visible light camera, and an infrared camera may be used, and the camera type may be changed according to the environment, or may be used in combination.

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

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

  Although the vehicle speed sensor 8 is shown in FIG. 1 to measure the rotational speed of one tire and calculate the vehicle speed, the present invention is not limited to this, and the average value of the rotational speeds of four tires is not limited thereto. 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 assistance apparatus 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 detection unit 10, an object detection unit 40, a distance detection unit 50, a distance calculation unit 60, a vehicle control unit 70, a vehicle speed control unit 80, and an alarm unit 90.

  The lane detection unit 10 detects the curvature of the traveling lane on the traveling path in front of the vehicle and the current lateral position of the host vehicle in the traveling lane based on the camera information output from the front camera 5. A known method can be used as a method of detecting the curvature of the traveling lane and the current lateral position of the host vehicle by the front camera. For example, for a video signal obtained by imaging the front with the front camera 5, 2 is used. Performs digitized image processing and edge detection processing, detects white lines on the left and right of the host vehicle by Hough transform, etc., finds the relative position of the left and right white lines with respect to the host vehicle, and determines the current lateral position of the host vehicle, that is, The distance from the center point and 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, although the method of using the pattern matching which extracts a characteristic shape is also mentioned as the method of detecting the white line of a driving lane, you may detect a white line using what kind of method.

  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 objects on the driving road ahead and around the driving road from the current driving position of the host vehicle. Detect. Here, objects on and around the road obtained based on the map data refer to structures and facilities where the distance between the vehicle and the object is close, such as a tunnel entrance and a toll collection point. Shall. By using map data, accurate information can be obtained. A method for 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 the location information of irregular objects on the road that cannot be obtained from map data can be obtained by road information and communication with surrounding vehicles, this is also treated as an object on and around the road. Can do.

  In addition, you may detect the object on the driving path ahead of the own vehicle, and the periphery of a driving path by pattern-matching the image data ahead of the own vehicle obtained from the front camera 5 without using map data. The distance to the object may be measured using millimeter wave radar, LIDAR (Light Detection and Ranging), or the like.

  The map data includes road curvature information that defines the degree of road curvature for each predetermined distance defined by 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 in the vicinity of 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 the distance between the host vehicle and an object on and around the traveling road. For example, since the current vehicle position obtained from the positioning satellite signal and the map data are used to determine the vehicle position on the map, the position information of the objects on and around the traveling road recorded in the map data and the vehicle The distance is detected from the car position. By using map data, accurate information can be obtained.

  The interval calculation unit 60 calculates the interval between the host vehicle and the travel lane. That is, based on the current lateral position of the host vehicle in the traveling lane output from the lane detection unit 10 and the lane width of the current traveling lane acquired from the map data stored in the map data storage device 30, The distance between the host vehicle and the travel lane is calculated based on the current lateral position. For example, if the center of the lane width (lane width / 2) is the center of the road, comparing the center of the road with the lateral position of the vehicle, it can be determined how far to the left or right side, The distance from the car can be calculated. If it is found from the current lateral position that the host vehicle is at the center of the lane, the distance between the host vehicle and the lane is lane width / 2 on both the left and right sides. The calculated interval between the host vehicle and the travel lane is output to the vehicle control unit 70.

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

Lateral position control amount = target lateral position (lane center) −current lateral position (1)
The target steering angle is obtained from the following formula (2) using the curvature of the travel lane and the lateral position control amount, and the host vehicle is controlled to remain in the travel lane.

Target steering angle = K1 × curvature of front lane + K2 × lateral position control amount (2)
K1 and K2 are parameters, which are set in advance according to vehicle characteristics and the like. The calculated target steering angle is input to the steering motor / ECU 4. Formulas (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 it to the steering motor / ECU 4.

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

<Operation>
Next, a driving support method in the driving support apparatus 100 will be described using the 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 detection unit 10 detects the traveling lane based on the camera information output from the front camera 5, and the vehicle The curvature of the driving 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 an object exists on the road ahead and around the current road from the current travel position. If there is an object, the distance detection unit 50 determines whether the object is present. The distance is detected (step S102). Here, the object on the road ahead and around the road is meant to refer to structures and facilities such as tunnel entrances and toll collection stations. Note that if there is no object on the road ahead and around the current road position, the process proceeds to step S105, but the path 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 below the first threshold value (step S103). If it is below the first threshold value, the process proceeds to step S104, and if not, 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 performed depending on whether or not the following formula (3) is satisfied.

D_cal-V1 <0 (3)
When it progresses to step S104, the vehicle control part 70 is changed so that the 2nd threshold value used as the determination reference | standard which determines whether the space | interval of the own vehicle and a driving lane issues a warning may be enlarged. When the second threshold value before change is Y1, and the second threshold value after change is Y2, the value is changed as shown in the following formula (4).

Y1 <Y2 (4)
The reason for making such a change will be described with reference to FIG. 4 by taking as an example the case where the object on the road ahead and around the road is a tunnel. As shown in FIG. 4, before the own 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 is a case. In such a case, if the driver visually feels the inner wall of the tunnel close and a warning is issued suddenly, an excessive avoidance action may be taken. The same applies to toll collection stations.

  Therefore, before entering these structures and facilities, the second threshold value for determining whether or not the alarm should be given is increased so that the warning can be issued early. By increasing the second threshold value, it is easy to determine that an alarm should be issued.

  Further, whether or not to increase the second threshold value is determined based on the distance between the vehicle and the object so that the second threshold value can be changed before entering the tunnel. It is.

  When traveling in a tunnel, the width of the road shoulder is narrowed as described above, so that the margin between the traveling lane and the tunnel wall becomes relatively small, so when the tunnel is approaching forward Makes it possible to take an avoidance action such as bringing the vehicle closer to the center of the lane with a margin by enabling the warning to be issued earlier.

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

  When setting the position closer to the host vehicle by the distance V2 than 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 expressed by the following formula (5). The

D_sw = D_cal−V2 (5)
In the above formula (5), it is assumed that the relationship between the distance V2 and the first threshold value V1 is V2 ≦ V1. As V2 increases, an avoidance action with a margin becomes possible.

  In the present embodiment, when the second threshold value is increased in step S104, the vehicle control unit 70 instructs the 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, you can take evasive action with more margin. Here, as an example of the preset vehicle speed, there is a speed limit in accordance with the Road Traffic Law, and even if the road is curved as long as the speed limit is set according to the road, Yes.

  The vehicle control unit 70 calculates a target steering angle so that the vehicle travels along the travel lane detected in step S101 (step S105). First, the deviation between the current lateral position of the host vehicle detected by the lane detection unit 10 and the target lateral position set by the vehicle control unit 70 is calculated as a lateral position control amount. When 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 formula (6).

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

θt [deg] = K1 [deg · m] × Curv [1 / m] + K2 [deg / m] × ΔL [m] (7)
By performing the steering control of the host vehicle according to the target steering angle, the host vehicle can travel so as to stop in the travel lane. Further, when the host vehicle is driven so as to stop in the driving lane according to the target steering angle, an alarm is issued from the alarm device 9 when an operation that may cause the host vehicle to deviate from the driving lane is performed. (Lane departure warning) is issued.

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

  The interval calculation unit 60 calculates the interval between the host vehicle and the traveling lane, and determines whether or not the interval between the host vehicle and the traveling lane is below the second threshold value (step S106). In this case, case classification is performed using the road width W of the current travel position acquired from the map data stored in the map data storage device 30.

  That is, when the current lateral position L0 of the host vehicle is on the travel lane side with respect to half the lane width (W / 2), and when the current lateral position L0 of the host vehicle travels more than half the lane width (W / 2) Divide when you are away from the lane.

  In the former case, it is represented by the following formula (8), and in the former case, it is represented by the following formula (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 where the object on the road ahead and around the road is the tunnel TN and the host vehicle OV is running near the center line CL of the left lane of the road of two lanes on one side as in FIG. However, since W−Y1> L0, Expression (9) is not satisfied.

  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 Y1 and Y2 are set symmetrically with respect to the left and right sides of the vehicle in the lane. In addition, since the road may be a single lane when entering the tunnel, the same setting is made not only on the left side but also on the right side. The same applies to the toll collection lane.

  If the above formula (8) or (9) is satisfied, the process proceeds to step S107. If the formula (8) or (9) is not satisfied, a series of processing is terminated as it is not necessary to issue an alarm, and step S101 is performed. The following process is repeated.

  If it is determined in step S106 that the distance between the host vehicle and the travel lane is less 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 Then, the alarm unit 90 is controlled to output an alarm signal to the alarm device 9, and the alarm device 9 issues an alarm to warn the driver that the vehicle has performed an action that may deviate from the driving lane (step). S107).

  In step S107, the alarm device 9 issues an alarm by an audible means such as voice. At the same time, the alarm may be given by visual means such as blinking a warning light on a display such as an in-vehicle combination meter. By giving visual warnings together, it can be communicated to the driver more reliably. Furthermore, visual means for warning the driver that the vehicle and an object on and around the traveling road in front of the vehicle are approaching may be added.

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

  In addition, each part of the driving assistance 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 apparatus 100 shown in FIG. 2 is realized by the processing circuit 100 shown in FIG. 6, for example. A processor such as a CPU or 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 corresponds to, for example, a single circuit, a composite circuit, a programmed processor, a processor programmed in parallel, an ASIC, an FPGA, or a combination thereof. To do.

  FIG. 7 shows a hardware configuration when the driving support device 100 shown in FIG. 2 is configured using a processor. In this case, the function of each part of the driving support device 100 is realized by a combination of software and the like (software, firmware, or software and firmware). Software or the like is described as a program 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), thereby realizing the functions of the respective units.

  In the present invention, the embodiments can be appropriately modified and omitted within the scope of the invention.

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

Claims (8)

A lane detector for detecting a traveling lane in front of the vehicle;
A vehicle control unit that causes the vehicle to travel so as to remain in the travel lane;
An object detection unit for detecting objects on and around the traveling road ahead of the vehicle;
A distance detector for detecting 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 detecting unit, the vehicle and the traveling lane An interval calculation unit 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
Comparing the distance to a first threshold;
When the distance is less than the first threshold value, the second threshold value, which is a criterion for determining whether or not to issue the alarm based on the interval, is changed to increase,
The interval calculator is
Determining whether the interval is less than the second threshold;
The vehicle control unit
A driving assistance device that controls the alarm unit to issue the alarm when the interval is less than the second threshold value. The object detection unit is
The driving assistance device according to claim 1, wherein the object is detected using a current vehicle position obtained from a positioning satellite signal and map data. The distance detector is
The driving support device according to claim 1, wherein the distance between the vehicle and the object is detected using a current host vehicle position obtained from a positioning satellite signal and map data. The vehicle control unit
The driving support device according to claim 1, wherein when the second threshold value is increased, the vehicle speed of the vehicle is controlled to be changed to a preset vehicle speed. The preset vehicle speed is:
The driving support device according to claim 4, wherein the driving support device is a speed limit according to a road traffic law. The alarm unit is
The driving support device according to claim 1, wherein the warning is issued by an audible means and a visual means. The object is
The driving support device according to claim 1, comprising facilities and structures on and around the traveling road. (A) detecting a traveling lane in front of the vehicle;
(B) detecting an object on and around the traveling road ahead 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 step (a) and the lane width of the travel lane, the vehicle Calculating an interval between the vehicle and the travel lane;
(E) comparing the distance to a first threshold;
(F) When the distance is less than the first threshold value, a step of changing the second threshold value as a criterion for determining whether or not to issue an alarm based on the interval to be larger; ,
(G) determining whether the interval is below the second threshold;
(H) A driving support method comprising: issuing an alarm when the interval is less than the second threshold value.

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