Driving Support Devices

Abstract

To provide a driving support device capable of reducing discomfort of a driver by suppressing execution of control against an intention of the driver.SOLUTION: A driving support device acquires target information related to a target existing in the periphery of an own vehicle so as to control a steering device to restrict the own vehicle from deviating from a lane where the own vehicle is traveling. When it is detected that a large vehicle is traveling on a second lane adjacent to one end side in a width direction of a first lane where the own vehicle is traveling and also it is detected that a driver of the own vehicle is steering to allow the own vehicle to be deviated to the other end side in the width direction of the first lane, steering control is stopped. Besides, when it is detected that the own vehicle is deviated to the other end side in the width direction of the first lane, a warning device is allowed to issue low-level warning.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a driving assistance device having a function of preventing a vehicle from departing from a lane in which the vehicle is traveling. [Background technology]

[0002] There is known a driving assistance device (hereinafter referred to as "conventional device") that has a function of preventing the vehicle from deviating from the lane in which it is traveling (see, for example, Patent Document 1 below). When this conventional device detects, based on information acquired from an on-board sensor, that the vehicle has deviated toward one end in the width direction of the lane in which it is traveling, it controls the steering device so that the vehicle returns to the center in the width direction of the lane. Furthermore, when the vehicle deviates from the lane, the conventional device issues a specified warning. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-252500 A Summary of the Invention

[0004] When a vehicle (host vehicle) to which the above-mentioned conventional device is applied approaches a large vehicle traveling in a lane adjacent to one end in the width direction of the lane in which the host vehicle is traveling, the driver of the host vehicle may steer the host vehicle so as to deviate toward the other end in the width direction of the lane in which the host vehicle is traveling (the opposite side to the large vehicle). In this case, even though the driver is intentionally steering the host vehicle so as to deviate toward the other end in the width direction of the lane, the driver may feel annoyed if the above-mentioned lane departure suppression control is executed.

[0005] An object of the present invention is to provide a driving assistance device that can reduce discomfort to the driver by suppressing the execution of control contrary to the driver's intention.

[0006] In order to solve the above problems, a driving assistance device (1) according to the present invention comprises: an on-board sensor (20) that acquires and outputs target information relating to targets present around the vehicle; a control device (10) capable of executing steering control for controlling a steering device based on the target information so as to prevent the host vehicle from deviating from the lane in which the host vehicle is traveling, and warning control for controlling a warning device (40) so as to issue a predetermined warning to a driver of the host vehicle when the host vehicle deviates from the lane in which the host vehicle is traveling; Equipped with. The alarm device is capable of issuing a low-level alarm that is a low-level warning and a high-level alarm that is a high-level warning, The control device detects that a large vehicle is traveling in a second lane adjacent to one end in a width direction of a first lane in which the vehicle is traveling, and the driver of the vehicle steers the vehicle toward the other end in the width direction of the first lane. When it is detected that the vehicle is in a specific steering state, the steering control is stopped, and a specific lane departure has occurred in which the vehicle deviates to the other end side in the width direction of the first lane under the situation in which the vehicle is in the specific steering state. when detecting that the low level alarm is issued by the alarm device, When it is detected that the host vehicle has departed from a lane other than the specific lane, the high-level warning is issued. It is configured as follows.

[0007] In a vehicle (host vehicle) equipped with the driving assistance device according to the present invention configured as described above, when the driver steers the host vehicle away from a large vehicle traveling in an adjacent lane, steering control is not executed. As a result, even if the host vehicle deviates to the other end side of the lane (the side opposite to the large vehicle), only a low level warning is executed, and a high level warning is not executed. In other words, when the driver intentionally operates to move away from the large vehicle, automatic steering against the driver's intention is not executed. In addition, when the host vehicle deviates from the lane, a warning with a level lower than the attention level of the warning executed in normal times (when the control device does not detect a large vehicle) is executed. Therefore, according to the present invention, it is possible to suppress the execution of control against the driver's intention, thereby reducing the discomfort of the driver. [Brief description of the drawings]

[0008] [Figure 1]FIG. 1 is a block diagram of a vehicle control system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view showing a scene in which a vehicle is slightly offset to the left from the center in the width direction of the lane. [Diagram 3] FIG. 3 is a plan view showing the operation of the driving support device when the driving support device detects a large vehicle. [Figure 4] FIG. 4 is a flowchart of a program for implementing the lane departure prevention function. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (Outline of configuration) As shown in Fig. 1, a driving support device 1 according to an embodiment of the present invention is mounted on a vehicle V (hereinafter, may be referred to as "own vehicle"). The driving support device 1 has a function of preventing the own vehicle from departing from the lane in which it is traveling (lane departure prevention function).

[0010] (Specific configuration) As shown in FIG. 1, the driving assistance device 1 includes a driving assistance ECU 10, an in-vehicle sensor 20, a steering device 30, and an alarm device 40.

[0011] The driving assistance ECU 10 includes a microcomputer equipped with a CPU 10a, a ROM 10b, a RAM 10c, etc. In this specification, "ECU" means an electronic control unit, and includes a microcomputer equipped with a CPU, a ROM, a RAM, etc. The CPU realizes various functions by executing instructions stored in the ROM.

[0012] The driving assistance ECU 10 is connected to another ECU (an EPS·ECU 31, described later) via a CAN (Controller Area Network) so as to be able to transmit and receive information to and from the other ECU.

[0013] The on-board sensor 20 includes a sensor that acquires vehicle surrounding information (target information) including information about three-dimensional objects present around the vehicle V and information about road markings around the vehicle V. That is, for example, the on-board sensor 20 includes a sensor that acquires information about moving objects such as automobiles (other vehicles), pedestrians, and bicycles, as well as fixed objects such as white lines on the road, guardrails, and traffic lights.

[0014] Specifically, the on-board sensor 20 includes a radar sensor 21, an ultrasonic sensor 22, and a camera 23.

[0015] The radar sensor 21 includes a radar transmitting / receiving unit and a signal processing unit (not shown). The radar transmitting / receiving unit emits millimeter-wave band radio waves (hereinafter referred to as "millimeter waves") to the area around the vehicle, and receives millimeter waves reflected by a three-dimensional object present within the emission range (i.e., reflected waves). The signal processing unit calculates the distance between the vehicle V and the three-dimensional object, the relative speed between the vehicle V and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle V, etc. based on the phase difference between the transmitted millimeter wave and the received reflected wave, the attenuation level of the reflected wave, the time from transmitting the millimeter wave to receiving the reflected wave, etc., and transmits the results to the driving assistance ECU 10.

[0016] The ultrasonic sensor 22 transmits ultrasonic waves in a pulsed manner to a predetermined range around the vehicle and receives the reflected waves reflected by the three-dimensional object. The ultrasonic sensor 22 detects the "reflection point, which is the point on the three-dimensional object where the transmitted ultrasonic waves are reflected," and the "distance between the ultrasonic sensor and the three-dimensional object," based on the time from transmitting the ultrasonic waves to receiving the reflected waves. Based on the detection result, the ultrasonic sensor 22 calculates the distance between the vehicle V and the three-dimensional object, the relative speed between the vehicle V and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle V, and the like, and transmits them to the driving assistance ECU 10.

[0017] The camera 23 includes an imaging device and an image analysis device. The imaging device is, for example, a digital camera with a built-in imaging element such as a CCD (charge coupled device) or a CIS (CMOS image sensor). The imaging device is disposed on the upper part of the front windshield glass. The imaging device outputs image data obtained by photographing the front view of the vehicle at a predetermined frame rate to the image analysis device. The image analysis device analyzes the acquired image data and obtains information on a target located in front of the vehicle V from the image. The image analysis device, for example, recognizes white lines (division lines, stop lines, etc.) on the road and transmits the recognition result to the driving assistance ECU 10. In addition, the image analysis device detects the size and written contents of the license plate based on an image of the license plate part of a vehicle traveling in an adjacent lane, and determines whether the vehicle in the adjacent lane is a large vehicle (truck) based on the result. Then, the image analysis device transmits the determination result to the driving assistance ECU 10.

[0018] The on-vehicle sensor 20 further includes a sensor that acquires information regarding the running state (steering angle θ) of the vehicle V. Specifically, the on-vehicle sensor 20 includes a steering sensor 24.

[0019] The steering sensor 24 detects a steering angle θ (also called a steering angle or a turning angle) of the steering wheel. The steering sensor 24 transmits data indicating the detected steering angle θ to the driving assistance ECU 10.

[0020] The steering device 30 controls the steering angle of the steered wheels (left front wheel and right front wheel). The steering device 30 includes an electric power steering ECU (hereinafter referred to as "EPS·ECU") 31, an assist motor 32, and a steering mechanism 33. The EPS·ECU 31 is connected to the assist motor 32 (a drive circuit of the assist motor 32). The assist motor 32 is incorporated in the steering mechanism 33. The steering mechanism 33 is a mechanism for steering the steered wheels. The steering mechanism 33 includes a steering wheel SW, a steering shaft US, and a steering gear mechanism (not shown). The EPS·ECU 31 obtains a steering angle θ from the driving assistance ECU 10. The driving assistance ECU 10 can appropriately correct the steering angle θ obtained from the steering sensor 24 and transmit it to the EPS·ECU 31. The EPS·ECU 31 can transmit a steering command to the EPS·ECU 31 according to the steering angle θ obtained from the driving assistance ECU 10. When the EPS·ECU 31 receives a steering command from the driving assist ECU 10, it drives the assist motor 32 based on the steering command. In this manner, the steering angle of the steered wheels of the vehicle V (i.e., the steering angle) is controlled.

[0021] The warning device 40 includes a display device 41 and an audio device 42. The display device 41 is composed of a liquid crystal display device. The display device 41 acquires display data from the driving assistance ECU 10 and displays an image according to the display data. The audio device 42 is composed of an amplifier device and a speaker device. The audio device 42 acquires audio data from the driving assistance ECU 10 and plays audio according to the audio data.

[0022] (Lane departure prevention function) Next, the lane departure prevention function (LTA) of the driving assistance device 1 will be described. The driving assistance ECU 10 calculates a target driving line Ld based on information acquired from the radar sensor 21, the ultrasonic sensor 22, and the camera 23. As shown in FIG. 2, the target driving line Ld is a line extending approximately parallel to the white line RL (or a curb, a divider, etc.) on the right side of the lane on which the vehicle V is traveling and the white line LL (or a curb, a divider, etc.) on the left side of the lane. Next, the driving assistance ECU 10 calculates the deviation between the front end center position CL of the vehicle and the target driving line Ld (deviation to the right or left in the width direction of the lane (hereinafter referred to as "offset value OFS")).

[0023] Then, in a situation where the offset value OFS (absolute value) exceeds the threshold value OFSth, the driving assist ECU 10 controls the steering device 30 so that the offset value OFS coincides with "0." Hereinafter, this control will be referred to as "steering control."

[0024] Furthermore, when the driving assistance ECU 10 detects that the vehicle has deviated from the lane it has been traveling in (crossed a boundary line) based on information acquired from the on-board sensor 20, it causes the warning device 40 to issue a high level of warning to call the driver's attention. Specifically, the driving assistance ECU 10 causes the display device 41 to display a predetermined image and causes the audio device 42 to play a predetermined warning sound. Hereinafter, this control will be referred to as "high-level warning control."

[0025] However, when the driving assistance ECU 10 detects, based on information acquired from the in-vehicle sensor 20, that the following condition A1 and condition A2 are satisfied, the driving assistance ECU 10 does not execute steering control (see FIG. 3). (A1) A large vehicle (for example, a truck) is traveling in a lane adjacent to one end in the width direction of the lane in which the host vehicle is traveling. (A2) The driver is steering the vehicle so that the vehicle deviates toward the other end of the lane in the width direction.

[0026] In addition, when the driving assistance ECU 10 detects, based on information acquired from the on-board sensor 20, that condition A1 and condition A2 are satisfied and also that the following condition B is satisfied, the driving assistance ECU 10 causes the warning device 40 to issue a low-level warning to the driver. (B) The vehicle deviates from the lane in which it is traveling to the other end of the lane in the width direction. Specifically, the driving assistance ECU 10 causes the display device 41 to display a predetermined image as the warning, but does not cause the audio device 42 to play back a sound. Hereinafter, this control is referred to as "low-level warning control." Note that the attention level of the warning executed in the high-level warning control is higher than the attention level of the warning executed in the low-level warning control.

[0027] Next, the operation (program P1 that realizes the above-mentioned "lane departure suppression function") of the CPU 10a (hereinafter simply referred to as "CPU") of the driving assistance ECU 10 will be specifically described with reference to Fig. 4. While the engine of the host vehicle is operating (when the ignition switch is in the ON state), the CPU executes the program P1 at a predetermined cycle.

[0028] (Program P1) The CPU starts the execution of the program P1 from step 100 and proceeds to step 101.

[0029] When the CPU proceeds to step 101, it determines whether or not condition A1 is satisfied (whether or not a large vehicle is traveling in the adjacent lane). If condition A1 is satisfied (101: Yes), the CPU proceeds to step 105. On the other hand, if condition A1 is not satisfied (101: No), the CPU proceeds to step 102.

[0030] When the CPU proceeds to step 102, it executes steering control. Then, the CPU proceeds to step 103.

[0031] When the CPU proceeds to step 103, it determines whether or not the host vehicle has departed from the lane. If the host vehicle has departed from the lane (103: Yes), the CPU proceeds to step 104. On the other hand, if the host vehicle has not departed from the lane (103: No), the CPU proceeds to step 109 and ends the execution of the program P1.

[0032] When the CPU proceeds to step 104, it executes high-level alarm control. Then, the CPU proceeds to step 109.

[0033] When the CPU proceeds to step 105, it determines whether or not condition A2 is satisfied (whether or not the driver is steering in the opposite direction to the large vehicle). If condition A2 is satisfied (105: Yes), the CPU proceeds to step 106. On the other hand, if condition A2 is not satisfied (105: No), the CPU proceeds to step 102.

[0034] When the CPU proceeds to step 106, it stops the steering control (does not execute the steering control). Then, the CPU proceeds to step 107.

[0035] When the CPU proceeds to step 107, it determines whether or not condition B is satisfied (whether or not the host vehicle has deviated from the lane in which the host vehicle is traveling to the opposite side of the large vehicle). If condition B is satisfied (107: Yes), the CPU proceeds to step 108. On the other hand, if condition B is not satisfied (107: No), the CPU proceeds to step 109.

[0036] When the CPU proceeds to step 108, it executes low level warning control, and then proceeds to step 109.

[0037] (effect) In a vehicle equipped with the above-described driving assistance device 1, when the driver steers the vehicle away from a large vehicle traveling in an adjacent lane, steering control is not executed. As a result, even if the vehicle deviates to the other end side of the lane (the side opposite to the large vehicle), only a low-level warning is executed, and a high-level warning is not executed. In other words, when the driver intentionally operates to move away from the large vehicle, automatic steering against the driver's intention is not executed. In addition, when the vehicle deviates from the lane, a warning of a level lower than the attention level of the warning executed in normal times (when the driving assistance ECU 10 does not detect a large vehicle) is executed. Therefore, according to the present invention, the execution of control against the driver's intention can be suppressed, and the discomfort of the driver can be reduced.

[0038] The present invention is not limited to the above-described embodiment, and various modifications can be adopted within the scope of the present invention, as described below.

[0039] <Variation 1> In the above embodiment, the high-level warning control includes control for causing the display device 41 to display a predetermined image (display control) and control for causing the audio device 42 to play a predetermined warning sound (audio control). In addition, the high-level warning control may include control for causing the assist motor 32 to vibrate the steering wheel SW (vibration control). In this case, only the display control is executed as the low-level warning control, similarly to the above embodiment. [Explanation of symbols]

[0040] 1... driving assistance device, 10... driving assistance ECU, 20... in-vehicle sensor, 30... steering device, 40... warning device, V... vehicle, θ... steering angle

Claims

[Claim 1] an on-board sensor that acquires and outputs target information relating to targets present around the vehicle; a control device capable of executing a steering control for controlling a steering device based on the target information so as to prevent the host vehicle from departing from a lane in which the host vehicle is traveling, and an alarm control for controlling an alarm device so as to issue a predetermined alarm to a driver of the host vehicle when the host vehicle deviates from the lane in which the host vehicle is traveling; A driving assistance device comprising: The alarm device is capable of issuing a low-level alarm that is a low-level warning and a high-level alarm that is a high-level warning, The control device is configured to stop the steering control when it detects that a large vehicle is traveling in a second lane adjacent to one end in the width direction of a first lane in which the vehicle is traveling, and when it detects that the driver of the vehicle is in a specific steering state in which the vehicle is steering so as to bias the vehicle toward the other end in the width direction of the first lane, to cause the warning device to execute the low-level warning when it detects that a specific lane departure has occurred in which the vehicle deviates toward the other end in the width direction of the first lane while the specific steering state is detected, and to execute the high-level warning when it detects that a lane departure of the vehicle has occurred other than the specific lane departure.

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