Lane departure prevention device control device

Abstract

The invention comprises: a lane departure detection unit (130) for detecting lane departure; a rear vehicle determination unit (110) for determining whether there is a rear vehicle; a lane change start detection unit (140) for detecting the start of a lane change; a lane change completion detection unit (150) for detecting the completion of a lane change; a steering assist control unit (160) for applying an assist steering torque in a direction opposite to the lane departure direction to a steering wheel (21) within a prescribed period of time if a lane departure is detected so as to maintain the driving lane; and assist steering torque release units (170) and (180) for releasing the application of the assist steering torque if the start of a lane change is detected in the absence of a rear vehicle, and releasing the application of the assist steering torque if the completion of the lane change is detected in the presence of a rear vehicle.

Description

Technical Field

[0001] The present disclosure relates to a control device for a lane departure prevention device. Background Art

[0002] In such a lane departure prevention device, if the vehicle is about to depart from the lane, lane departure prevention is achieved by applying an auxiliary steering torque in the opposite direction of the vehicle's departure direction to the steering wheel. Such auxiliary steering torque is configured to be released by the driver performing a steering operation greater than a preset override threshold.

[0003] As one example of a lane departure prevention device, for example, Patent Document 1 discloses a technology that makes an overriding threshold value variable depending on the presence or absence of a rear vehicle traveling in an adjacent lane.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-146817 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] In the lane departure prevention device, in order to improve the effectiveness of lane departure prevention, it is preferred that the auxiliary steering torque in the direction opposite to the vehicle's departure direction is continuously applied within a prescribed period from the time of lane departure. However, if the auxiliary steering torque in the opposite direction is continuously applied after the vehicle changes lanes, this goes against the driver's intention when he or she wants to maintain the changed lane. That is, the driver is forced to perform a steering operation to overcome the auxiliary steering torque within the prescribed period, which is cumbersome.

[0009] In order to easily release such assist steering torque, it is conceivable to set the override threshold value to be low. However, if the override threshold value is lowered, the possibility of collision increases when there is a vehicle behind, which causes a problem that safety cannot be guaranteed.

[0010] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a control device for a lane departure prevention device that can effectively reduce the risk of a collision and effectively reflect the intention of a driver.

[0011] Technical means for solving technical problems

[0012] The technology disclosed in the present invention is characterized in that it includes: a lane departure detection unit that detects a lane departure of a vehicle from a driving lane; a rear vehicle determination unit that determines whether there is a rear vehicle behind the vehicle; a lane change start detection unit that detects the start of a lane change of the vehicle from the driving lane; a lane change completion detection unit that detects the completion of the lane change of the vehicle from the driving lane; a steering assist control unit that applies an assist steering torque in a direction opposite to the lane departure direction to a steering wheel for a predetermined period of time if the lane departure is detected so that the vehicle maintains the driving lane; and an assist steering torque release unit that releases the application of the assist steering torque if the lane change start detection unit detects the start of a lane change when the rear vehicle determination unit determines that there is no rear vehicle, and releases the application of the assist steering torque if the lane change completion detection unit detects the completion of the lane change when the rear vehicle determination unit determines that there is a rear vehicle.

[0013] Furthermore, it is preferable that the assist steering torque canceling unit cancels the application of the assist steering torque when an elapsed time from the start of application of the assist steering torque reaches a predetermined upper limit threshold time.

[0014] In addition, preferably, when the rear vehicle determination unit determines that there is no rear vehicle, the auxiliary steering torque release unit releases the application of the auxiliary steering torque if the torque of the steering operation performed by the driver exceeds a prescribed first threshold torque, and on the other hand, when the rear vehicle determination unit determines that there is a rear vehicle, if the torque of the steering operation performed by the driver exceeds a prescribed second threshold torque that is greater than the first threshold torque, the application of the auxiliary steering torque is released.

[0015] Effects of the Invention

[0016] According to the technology of the present disclosure, it is possible to effectively reduce the risk of a collision and effectively reflect the driver's intention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a diagram schematically showing the overall configuration of a vehicle equipped with a control device for a lane departure prevention device according to the present embodiment.

[0018] Figure 2 This is a schematic functional block diagram showing the control device and related peripheral structures according to the present embodiment.

[0019] Figure 3 FIG. 1 is a diagram schematically showing an optical warning performed in the steering assist control according to the present embodiment.

[0020] Figure 4This is a flowchart illustrating the flow of the processing of the steering assist control and the release of the steering assist control according to the present embodiment. DETAILED DESCRIPTION

[0021] The following describes the control device of the lane departure prevention device according to the present embodiment based on the drawings. The same reference numerals are given to the same components, and their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0022] Figure 1 1 is a diagram schematically showing the overall configuration of a vehicle 1 equipped with a control device 100 for the lane departure prevention device according to the present embodiment.

[0023] The vehicle 1 is equipped with an engine 10 as an example of a driving force source. The engine 10 is connected to driving wheels 2L and 2R via a clutch device (not shown), a transmission (not shown), a transmission shaft 11, a differential gear device 12, and left and right driving shafts 13L and 13R. In addition, the vehicle 1 is not limited to a rear-wheel drive vehicle, but may be a front-wheel drive vehicle or a four-wheel drive vehicle. In addition, the driving force source is not limited to the engine, but may be a driving motor, or a hybrid vehicle using both of them.

[0024] The vehicle 1 is provided with a steering device 20. The steering device 20 includes: a steering wheel 21 operated by a driver; a steering shaft 22 connected to the steering wheel 21 at one end; a rack and pinion (or power cylinder) mechanism 23 connected to the other end of the steering shaft 22; and left and right link mechanisms 24L and 24R connecting the rack and pinion mechanism 23 and the left and right steering wheels 3L and 3R.

[0025] The steering device 20 is provided with a steering motor 25. The steering motor 25 is provided on the steering shaft 22, and applies a steering torque to the steering shaft 22 by driving. In addition, the steering motor 25 is not limited to the column-assisted type shown in the example, and may be a pinion-assisted type or a rack-assisted type that transmits torque to the rack-and-pinion mechanism 23. The steering motor 25 is driven by power supplied from the battery 50. The driving of the steering motor 25 is controlled according to a command from the control device 100.

[0026] The vehicle 1 is provided with a meter display unit 5. The meter display unit 5 displays various information of the vehicle 1, such as the vehicle speed. In addition, the meter display unit 5 displays a warning during the steering assist control described later. In addition, the vehicle 1 is provided with left and right door mirrors 4L and 4R. The door mirrors 4L and 4R display a warning during the steering assist control.

[0027] The steering angle sensor 61 is provided on the steering shaft 22, and detects the steering angle corresponding to the rotation amount of the steering shaft 22. The vehicle speed sensor 62 detects the current vehicle speed of the vehicle 1 from the transmission shaft or the like. In addition, the vehicle speed sensor 62 may also be a wheel speed sensor. The torque sensor 63 is provided on the steering shaft 22, and detects the steering torque corresponding to the steering of the steering wheel 21. The accelerator pedal sensor 64 detects the depression amount of the accelerator pedal (not shown). The sensor values ​​of each of these sensors 61 to 64 are sent to the control device 100.

[0028] The left rear side millimeter wave radar 65L obtains the distance and relative speed between the vehicle 1 and the vehicle on the left rear side. The right rear side millimeter wave radar 65R obtains the distance and relative speed between the vehicle 1 and the vehicle on the right rear side. The distance and relative speed to the vehicle on the rear side obtained by each rear side millimeter wave radar 65L, 65R are sent to the control device 100.

[0029] The front camera 71 is, for example, a stereo camera, and captures the lane in front of the vehicle 1 to generate image data of the lane in front. Alternatively, the front camera 71 may be a single-lens camera. The image data generated by the front camera 71 is sent to the control device 100.

[0030] Figure 2 1 is a schematic functional block diagram showing the control device 100 and related peripheral structures according to the present embodiment.

[0031] The control device 100 is a device that performs calculations, such as a computer, and includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input port, an output port, etc., which are connected to each other via a bus, etc., and executes a control program. In addition, the control device 100 functions as a device including a rear vehicle determination unit 110, a driving state acquisition unit 120, a deviation determination unit 130, a lane change start determination unit 140, a lane change end determination unit 150, a steering assist control unit 160, a first assist steering torque release unit 170, a second assist steering torque release unit 180, and a warning processing unit 190 by executing the control program.

[0032] The rear vehicle determination unit 110 determines whether there is a vehicle behind the vehicle 1 based on the distance and relative speed to the rear vehicle transmitted from the rear millimeter-wave radars 65L and 65R. The determination result of the rear vehicle determination unit 110 is transmitted to the steering assist control unit 160 .

[0033] The driving state acquisition unit 120 acquires the driving state of the vehicle 1 based on the steering angle sent from the steering angle sensor 61 , the vehicle speed sent from the vehicle speed sensor 62 , the steering torque sent from the torque sensor 63 , etc. The driving state acquired by the driving state acquisition unit 120 is sent to the steering assist control unit 160 .

[0034] The deviation determination unit 130 (an example of the lane departure detection unit of the present disclosure) determines whether the vehicle 1 has deviated from the driving lane. Specifically, the deviation determination unit 130 detects the boundary line (white line or yellow line) dividing the lane by performing image recognition processing on the image data sent from the front camera 71. Then, if the interval from the vehicle 1 to the boundary line is less than a predetermined first threshold interval, the deviation determination unit 130 determines that the vehicle 1 has deviated from the driving lane. The determination result of the deviation determination unit 130 is sent to the steering assist control unit 160.

[0035] The lane change start determination unit 140 (an example of the lane change start detection unit of the present disclosure) determines whether the vehicle 1 has started a lane change. Specifically, the lane change start determination unit 140 detects a boundary line (white line or yellow line) dividing the lanes by performing image recognition processing on the image data sent from the front camera 71. Then, the lane change start determination unit 140 detects the driver's lane change intention based on, for example, the steering torque sent from the driving state acquisition unit 120, the operation of the direction indicator (not shown), etc., and determines that the vehicle 1 has started a lane change if the vehicle 1 reaches the boundary line. The determination result of the lane change start determination unit 140 is sent to the lane change end determination unit 150 and the first assist steering torque release unit 170.

[0036] The lane change completion determination unit 150 (an example of the lane change completion detection unit of the present disclosure) determines whether the vehicle 1 has completed the lane change. Specifically, the lane change completion determination unit 150 detects the boundary line (white line or yellow line) that divides the lane in which the vehicle 1 is currently traveling by performing image recognition processing on the image data sent from the front camera 71. Then, after the lane change start determination unit 140 determines that the lane change has started, if the interval between the vehicle 1 and the boundary line reaches a predetermined second threshold interval, the lane change completion determination unit 150 determines that the vehicle 1 has completed the lane change. The determination result of the lane change completion determination unit 150 is sent to the second assist steering torque release unit 180.

[0037] When the deviation determination unit 130 determines that it is a lane departure and the vehicle speed of the vehicle 1 sent from the driving state acquisition unit 120 is within a specified speed range (for example, 60 to 130 km / h), the steering assist control unit 160 implements steering assist control to apply an auxiliary steering torque to the steering wheel 21 to prevent the vehicle 1 from deviating from the lane.

[0038] Specifically, the steering assist control unit 160 calculates the direction and torque for preventing the deviation based on the driving state transmitted from the driving state acquisition unit 120, controls the driving of the steering motor 25 based on these, and performs the steering assist control by applying the auxiliary steering torque in the direction opposite to the deviation direction to the steering wheel 21. The steering assist control started by the steering assist control unit 160 ends when the deviation determination unit 130 determines that the deviation is cancelled or when the auxiliary steering torque cancellation units 170 and 180 cancel the deviation.

[0039] When the rear vehicle determination unit 110 determines that there is no rear vehicle, if the steering torque based on the driver exceeds a predetermined first override threshold value (e.g., 11N (2Nm)), the first auxiliary steering torque release unit 170 immediately releases the auxiliary steering torque application by the steering assist control. Thus, when there is no rear vehicle, in other words, when the possibility of collision with the rear vehicle is low, the driver's intention to change lanes can be effectively reflected.

[0040] Furthermore, even when the driver's steering torque is below the first override threshold, if any of the following first release conditions (1) and (2) is satisfied, the first auxiliary steering torque release unit 170 immediately releases the auxiliary steering torque applied by the steering assist control. (1) When the lane change start determination unit 140 determines that a lane change has been started during the implementation of the steering assist control. (2) When the time elapsed from the start of the auxiliary steering torque applied by the steering assist control exceeds a predetermined upper threshold time (e.g., 9 seconds).

[0041] In this way, when there is no rear vehicle (the possibility of collision with the rear vehicle is low), if the start of lane change of the vehicle 1 is detected, the auxiliary steering torque is immediately released, which can effectively reflect the driver's lane change intention. In addition, if the upper limit time is reached, the auxiliary steering torque is immediately released, which can also effectively reduce the trouble caused by implementing the steering assist control for a long time.

[0042] When the rear vehicle determination unit 110 determines that there is a rear vehicle, if the steering torque based on the driver exceeds the second overriding threshold (for example, 21N (4Nm)) that is larger than the first overriding threshold, the second auxiliary steering torque release unit 180 immediately releases the auxiliary steering torque application by the steering assist control. Thus, when there is a rear vehicle, in other words, when the possibility of collision with the rear vehicle is high, the possibility of collision with the rear vehicle can be effectively reduced.

[0043] Furthermore, even when the driver's steering torque is below the second override threshold, if any of the following second release conditions (1) and (2) is satisfied, the second auxiliary steering torque release unit 180 immediately releases the auxiliary steering torque applied by the steering assist control. (1) When the lane change end determination unit 150 determines that the lane change is completed during the implementation of the steering assist control. (2) When the time elapsed from the start of the auxiliary steering torque application by the steering assist control exceeds a predetermined upper threshold time (e.g., 9 seconds).

[0044] In this way, when there is a rear vehicle (with a high possibility of collision with the rear vehicle), the application of the auxiliary steering torque is made effective until the lane change of the vehicle 1 is completed. If the lane change of the vehicle 1 is detected to be completed, the application of the auxiliary steering torque is immediately released, which can effectively prevent the collision with the rear vehicle and effectively reflect the driver's lane change intention. In addition, if the upper limit time is reached, the application of the auxiliary steering torque is immediately released, which can also effectively reduce the trouble caused by implementing the steering assist control for a long time.

[0045] When the rear vehicle determination unit 110 determines that there is no rear vehicle, if the steering assist control unit 160 starts the steering assist control, the warning processing unit 190 implements an optical warning that displays a lane departure warning for at least 1 second on the instrument display unit 5. In addition, when the rear vehicle determination unit 110 determines that there is no rear vehicle, if the steering assist control unit 160 starts the steering assist control, the warning processing unit 190 implements a vibration warning that causes the steering wheel 21 to vibrate through the steering motor 25. In this way, the driver can be effectively notified that the steering assist control is being implemented due to the lane departure of the vehicle 1.

[0046] In addition, when the rear vehicle determination unit 110 determines that there is a rear vehicle, if the steering assist control unit 160 starts the steering assist control, the warning processing unit 190 implements an optical warning, and displays a warning of the presence of a rear vehicle on the door mirror 4 (for example, the door mirror 4L) on the side where the rear vehicle exists for at least one second (refer to Figure 3 ). In this way, by directing the driver's attention to the door mirror 4, the presence of the rear vehicle can be visually notified, thereby achieving collision prevention.

[0047] Next, refer to Figure 4 The flow of the steering assist control and the process of releasing the steering assist control according to the present embodiment will be described with reference to the flowchart of FIG. This control is started, for example, simultaneously with the turning-on operation of the ignition switch.

[0048] First, in step S100, it is determined whether the vehicle speed is within a specified speed range, for example, 60 to 130 km / h. If it is determined that the vehicle speed is not within the specified speed range (No), the control returns. On the other hand, if it is determined that the vehicle speed is within the specified speed range (Yes), the control proceeds to step S110.

[0049] In step S110, it is determined whether the vehicle 1 has deviated from the driving lane. If it is determined that the vehicle 1 has deviated from the driving lane (Yes), the control proceeds to step S120. On the other hand, if it is determined that the vehicle 1 has not deviated from the driving lane (No), the control returns.

[0050] In step S120, it is determined whether there is a vehicle behind the vehicle 1. If it is determined that there is a vehicle behind the vehicle 1 (Yes), the control proceeds to step S200. If it is determined that there is no vehicle behind the vehicle 1 (No), the control proceeds to step S130.

[0051] In step S130 , while the steering assist control is being executed, an optical warning and a vibration warning are executed via the meter display unit 5 .

[0052] In step S140, it is determined whether the steering torque exceeds the first override threshold. If the steering torque exceeds the first override threshold (yes), the control proceeds to step S160. If the steering torque does not exceed the first override threshold (no), the control proceeds to step S150.

[0053] In step S150, it is determined whether the first cancellation condition is satisfied. If the first cancellation condition is satisfied (Yes), the control proceeds to step S160. If the first cancellation condition is not satisfied (No), the control returns to step S120.

[0054] In step S160, the steering assist control is canceled and the warning is canceled, after which the control returns.

[0055] As described above, in step S120 , when it is determined that there is a vehicle to the rear side of the vehicle 1 (Yes), the control proceeds to step S200 .

[0056] In step S200 , steering assist control is implemented, and optical warning and audible warning via the door mirror 4 are implemented.

[0057] In step S210, it is determined whether the steering torque exceeds the second override threshold. If the steering torque exceeds the second override threshold (yes), the control proceeds to step S230. If the steering torque does not exceed the second override threshold (no), the control proceeds to step S220.

[0058] In step S220, it is determined whether the second cancellation condition is satisfied. If the second cancellation condition is satisfied (Yes), the control proceeds to step S230. If the second cancellation condition is not satisfied (No), the control returns to step S120.

[0059] In step S230 , the steering assist control is released and the warning is released, after which the control returns.

[0060] In addition, the present disclosure is not limited to the above-described embodiment, and can be implemented with appropriate modifications within the scope not departing from the gist of the present disclosure.

[0061] This application is based on Japanese patent application (Japanese Patent Application No. 2020-007127) filed on January 20, 2020, the contents of which are incorporated herein by reference.

[0062] Industrial Availability

[0063] The control device of the lane departure prevention device of the present disclosure is useful in that it can effectively reduce the risk of a collision and effectively reflect the intention of the driver.

[0064] Description of Reference Numerals

[0065] 1 Vehicle

[0066] 4L, 4R door mirrors

[0067] 5 Instrument display

[0068] 10 Engine

[0069] 20 Steering device

[0070] 21 Steering Wheel

[0071] 25 Steering motor

[0072] 65L, 65R rear side millimeter wave radar

[0073] 71 Front Camera

[0074] 100 Control device

[0075] 110 Rear vehicle detection unit

[0076] 120 Driving status acquisition unit

[0077] 130 Departure determination unit (lane departure detection unit)

[0078] 140 Lane change start determination unit (lane change start detection unit)

[0079] 150 Lane change completion determination unit (lane change completion detection unit)

[0080] 160 Steering assist control unit

[0081] 170 First assist steering torque release unit (assist steering torque release unit)

[0082] 180 Second assist steering torque release unit (assist steering torque release unit)

[0083] 190 Warning Processing Department

Claims

1. A control device for a lane departure prevention device, characterized in that: include: a lane departure detection unit that detects a lane departure of the vehicle from a driving lane; a rear vehicle determination unit that determines whether there is a rear vehicle behind the vehicle; a lane change start detection unit configured to detect a lane change start of the vehicle from the driving lane; a lane change completion detection unit configured to detect completion of a lane change of the vehicle from the driving lane; a steering assist control unit, which applies an assist steering torque in a direction opposite to the lane departure direction to a steering wheel within a predetermined period of time so that the vehicle maintains the driving lane if the lane departure is detected; and The auxiliary steering torque release unit releases the application of the auxiliary steering torque if the lane change start detection unit detects the start of a lane change when the rear vehicle determination unit determines that there is no rear vehicle. On the other hand, if the lane change completion detection unit detects the completion of the lane change when the rear vehicle determination unit determines that there is a rear vehicle, the auxiliary steering torque release unit releases the application of the auxiliary steering torque.

2. The control device for the lane departure prevention device according to claim 1, wherein: The assist steering torque canceling unit cancels the application of the assist steering torque when an elapsed time from the start of application of the assist steering torque reaches a predetermined upper limit threshold time.

3. The control device for the lane departure prevention device according to claim 1, wherein: When the rear vehicle determination unit determines that there is no rear vehicle, if the torque of the steering operation performed by the driver exceeds a prescribed first threshold torque, the auxiliary steering torque release unit releases the application of the auxiliary steering torque. On the other hand, when the rear vehicle determination unit determines that there is a rear vehicle, if the torque of the steering operation performed by the driver exceeds a prescribed second threshold torque that is greater than the first threshold torque, the auxiliary steering torque release unit releases the application of the auxiliary steering torque.

4. The control device for the lane departure prevention device according to claim 2, wherein: When the rear vehicle determination unit determines that there is no rear vehicle, if the torque of the steering operation performed by the driver exceeds a prescribed first threshold torque, the auxiliary steering torque release unit releases the application of the auxiliary steering torque. On the other hand, when the rear vehicle determination unit determines that there is a rear vehicle, if the torque of the steering operation performed by the driver exceeds a prescribed second threshold torque that is greater than the first threshold torque, the auxiliary steering torque release unit releases the application of the auxiliary steering torque.

5. A control method for a lane departure prevention device, characterized in that: have: a lane departure detection step of detecting a lane departure of the vehicle from a driving lane; A rear vehicle determination step of determining whether there is a rear vehicle behind the vehicle; a lane change start detection step of detecting that the vehicle starts a lane change from the driving lane; a lane change completion detection step of detecting that the lane change of the vehicle from the driving lane is completed; a steering assist control step, if the lane departure is detected, applying an assist steering torque in a direction opposite to the lane departure direction to the steering wheel within a predetermined period so that the vehicle maintains the driving lane; as well as The auxiliary steering torque release step releases the application of the auxiliary steering torque when it is determined in the rear vehicle determination step that there is no rear vehicle and the lane change start detection step detects the start of the lane change, and releases the application of the auxiliary steering torque when it is determined in the rear vehicle determination step that there is a rear vehicle and the lane change completion detection step detects the completion of the lane change.

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