Driving assistance systems

Abstract

To provide a driving support device that improves a technology for detecting other vehicles following a vehicle.SOLUTION: In a vehicle 1, a driving support device 40 includes a control unit 45. When another vehicle behind a host vehicle changes a lane into the same lane as the host vehicle within a predetermined time after detecting a lane change of the host vehicle, the control unit 45 determines whether the other vehicle is following the host vehicle. When the distance between the other vehicle and the host vehicle is less than a predetermined distance or the distance between the other vehicle and the host vehicle becomes shorter over time, it is determined that the other vehicle is following the host vehicle.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a driving support device.

Background Art

[0002] Conventionally, a technique for detecting another vehicle that rear-ends the host vehicle has been known. For example, Patent Document 1 describes an in-vehicle notification device that determines whether or not a following vehicle is rear-ending the host vehicle based on detection information by a rear situation detection unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is room for improvement in the conventional technique for detecting another vehicle that rear-ends the host vehicle. For example, the other vehicle that rear-ends the host vehicle does not always continuously rear-end directly behind the host vehicle.

[0005] In view of this point, an object of the present disclosure is to improve the technique for detecting another vehicle that rear-ends the host vehicle.

Means for Solving the Problems

[0006] A driving support device according to an embodiment of the present disclosure includes a control unit that determines whether or not the other vehicle is rear-ending the host vehicle when the other vehicle behind the host vehicle changes lanes to the same lane as the host vehicle within a predetermined time after detecting a lane change of the host vehicle.

Effects of the Invention

[0007] According to an embodiment of the present disclosure, the technique for detecting another vehicle that rear-ends the host vehicle can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram of a vehicle according to one embodiment of the present disclosure. [Figure 2] This flowchart shows an example of a procedure for a driver assistance method according to one embodiment of the present disclosure. [Figure 3] This diagram illustrates how your vehicle and other vehicles change lanes. [Modes for carrying out the invention]

[0009] The embodiments relating to this disclosure will be described below with reference to the drawings.

[0010] As shown in Figure 1, the vehicle 1 includes a plurality of electronic control units 10, a display device 20, a rear camera 30, and a driver assistance device 40. The vehicle 1 may further include a ranging device such as a microwave radar, millimeter-wave radar, or LiDAR (Light Detection and Ranging). The number of electronic control units 10 included in the vehicle 1 may be one.

[0011] The electronic control unit 10, the display device 20, the rear camera 30, and the driver assistance device 40 can communicate with each other via the communication line 2. The communication line 2 may be any communication line, including an in-vehicle network such as CAN (Controller Area Network) and a dedicated line.

[0012] The electronic control unit 10 is the ECU (Electronic Control Unit) of the vehicle 1. The electronic control unit 10 controls various functions of the vehicle 1.

[0013] The display device 20 is, for example, a digital mirror such as a digital rearview mirror. The display device 20 is positioned in a location visible from the driver's seat of the vehicle 1. For example, the display device 20 is positioned in the location of a rearview mirror. The display device 20 consists of a display. The display is, for example, an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display. The display device 20 displays the image generated by the rear camera 30.

[0014] The rear camera 30 generates a continuous video feed of the area behind the vehicle 1. The rear camera 30 transmits the generated video data to the display device 20 and the driver assistance device 40 via the communication line 2.

[0015] The driver assistance device 40 is, for example, a car navigation system. The driver assistance device 40 comprises a communication unit 41, an input unit 42, an output unit 43, a storage unit 44, and a control unit 45.

[0016] The communication unit 41 is comprised of at least one communication module capable of communicating with components of the vehicle 1 via the communication line 2. The communication module is, for example, a communication module that conforms to the standards of an in-vehicle network or a dedicated line.

[0017] The input unit 42 is capable of receiving input from the user. The input unit 42 is configured to include at least one input interface capable of receiving input from the user. The input interface is, for example, a physical key, a capacitive key, a pointing device, a touchscreen integrated with a display, or a microphone.

[0018] The output unit 43 is capable of outputting data. The output unit 43 is configured to include at least one output interface capable of outputting data. The output interface is, for example, a display or a speaker. The display is, for example, an LCD or an organic EL display.

[0019] The storage unit 44 is configured to include at least one semiconductor memory, at least one magnetic memory, at least one optical memory, or a combination of at least two of these. The storage unit 44 may function as a main memory device, an auxiliary memory device, or a cache memory. The storage unit 44 stores data used for the operation of the driving support device 40 and data obtained by the operation of the driving support device 40.

[0020] The control unit 45 is configured to include at least one processor, at least one dedicated circuit, or a combination of these. The processor is, for example, a general-purpose processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), or a dedicated processor specialized for specific processing. The control unit 45 executes processing related to the operation of the driving support device 40 while controlling each part of the driving support device 40.

[0021] The control unit 45 may receive, via the communication line 2, data of an image generated by the rear camera 30 from the rear camera 30 by the communication unit 41. The control unit 45 may receive, via the communication line 2, information on the steering angle of the wheels of the vehicle 1 from the electronic control unit 10 by the communication unit 41.

[0022] FIG. 2 is a flowchart showing an example of the procedure of a driving support method according to an embodiment of the present disclosure. When the vehicle 1 starts traveling on a road where lane change is possible, the control unit 45 of the driving support device 40 starts the processing of step S1. A road where lane change is possible is, for example, an expressway or a highway dedicated for automobiles.

[0023] In the processing of step S1, the control unit 45 determines whether or not a lane change of the vehicle 1, that is, the host vehicle, has been detected. The control unit 45 may detect a lane change of the vehicle 1 by analyzing information on the steering angle of the wheels of the vehicle 1 or an image generated by the rear camera 30.

[0024] If the control unit 45 determines that it has detected a lane change by its own vehicle (step S1: YES), it proceeds to step S2. On the other hand, if the control unit 45 does not determine that it has detected a lane change by its own vehicle (step S1: NO), it repeats the process of step S1.

[0025] In step S2, the control unit 45 determines whether the other vehicle behind vehicle 1 has changed lanes into the same lane as vehicle 1. The control unit 45 may determine whether the other vehicle behind vehicle 1 has changed lanes into the same lane as vehicle 1 by analyzing the video generated by the rear camera 30. Here, the other vehicle whose lane change status is determined only needs to be another vehicle behind vehicle 1. In other words, the other vehicle whose lane change status is determined may be a vehicle that was driving immediately behind vehicle 1 before vehicle 1 changed lanes, or it may not be a vehicle that was driving immediately behind vehicle 1. Also, the other vehicle whose lane change status is determined may be a vehicle that was driving in the same lane as vehicle 1 before vehicle 1 changed lanes, or it may not be a vehicle that was driving in the same lane as vehicle 1. For example, in Figure 3, after vehicle 1 changes lanes, vehicle 3 behind vehicle 1 changes lanes. Before vehicle 1 changes lanes, the vehicle traveling immediately behind vehicle 1 is not vehicle 3, but vehicle 4. Even in such a case, after the control unit 45 determines that it has detected its own vehicle changing lanes (step S1: YES), it determines through the processing in step S2 that vehicle 3, i.e., another vehicle, has changed lanes.

[0026] If the control unit 45 determines that another vehicle behind vehicle 1 has changed lanes to the same lane as vehicle 1 (step S2: YES), it proceeds to step S4. If the control unit 45 does not determine that another vehicle behind vehicle 1 has changed lanes to the same lane as vehicle 1 (step S2: NO), it proceeds to step S3.

[0027] In step S3, the control unit 45 determines whether a predetermined time has elapsed since detecting the vehicle's lane change. The predetermined time may be set based on the estimated time it takes for another vehicle to change lanes in order to follow the vehicle that has changed lanes. For example, the predetermined time may be a few seconds. If the control unit 45 determines that a predetermined time has elapsed since detecting the vehicle's lane change (step S3: YES), it terminates the processing of the driving assistance method. On the other hand, if the control unit 45 does not determine that a predetermined time has elapsed since detecting the vehicle's lane change (step S3: NO), it returns to the processing of step S2.

[0028] Through the processing in steps S4, S5, S6, and S7, the control unit 45 determines whether the other vehicle that was determined to have changed lanes in the processing of step S2 is following the vehicle.

[0029] In step S4, the control unit 45 measures the distance between the vehicle and the other vehicle that was determined to have changed lanes in step S2. The control unit 45 may measure the distance between the vehicle and the other vehicle by analyzing the video generated by the rear camera 30. Alternatively, if the vehicle 1 includes a rangefinder, the control unit 45 may measure the distance between the vehicle and the other vehicle using the rangefinder.

[0030] In step S5, the control unit 45 determines whether the distance measured in step S4 is less than a predetermined distance. The predetermined distance may be set based on the distance between the vehicle and the other vehicle when the other vehicle is following the vehicle.

[0031] If the control unit 45 determines that the measured distance exceeds a predetermined distance (step S5: NO), it determines that the other vehicle that was determined to have changed lanes in step S2 is not following the vehicle (step S6). After the processing in step S6, the control unit 45 terminates the processing of the driving assistance method.

[0032] If the control unit 45 determines that the measured distance is less than a predetermined distance (step S5: YES), it determines that the other vehicle that was determined to have changed lanes in step S2 is following the vehicle (step S7). In step S7, the control unit 45 identifies the other vehicle that was determined to have changed lanes in step S2 as the following vehicle. After step S7, the control unit 45 proceeds to step S8.

[0033] In step S8, the control unit 45 notifies the driver of vehicle 1, i.e., the driver of the vehicle itself, of the presence of the pursuing vehicle. For example, the control unit 45 notifies the driver of the vehicle itself of the presence of the pursuing vehicle by outputting the voice message "There is a pursuing vehicle" from the speaker of the output unit 43. As a result of the execution of step S8, the driver of vehicle 1 becomes aware of the presence of the pursuing vehicle. By becoming aware of the presence of the pursuing vehicle, the driver of vehicle 1 can recognize the danger posed by the pursuing vehicle, for example, if the pursuing vehicle is driving aggressively.

[0034] In step S9, the control unit 45 causes the output unit 43 to output a query asking whether or not to switch to telephoto mode. For example, the control unit 45 outputs the voice message "Do you want to switch to telephoto mode?" to the speaker of the output unit 43. Telephoto mode is a mode in which the rear camera 30 magnifies and photographs the subject to a set magnification. The set magnification is, for example, a magnification such that the driver's seat of the pursuing vehicle is visible in the image captured by the rear camera 30. The driver of vehicle 1 may want to confirm what kind of person the driver of the pursuing vehicle is. In this case, the driver of vehicle 1 inputs an input to the input unit 42 indicating that they want to switch to telephoto mode. For example, the driver of vehicle 1 inputs the voice message "Please switch to telephoto mode" to the microphone of the input unit 42. Alternatively, the driver of vehicle 1 may input an input to the input unit 42 indicating that they want to switch to telephoto mode by operating the physical keys of the input unit 42.

[0035] In step S10, the control unit 45 determines whether or not it has received an input from the input unit 42 indicating a response to switch to telephoto mode. If the control unit 45 determines that it has received an input indicating a response to switch to telephoto mode (step S10: YES), it proceeds to step S11. On the other hand, if the control unit 45 determines that it has received an input indicating that it will not switch to telephoto mode (step S10: NO), it terminates the processing of the driving assistance method.

[0036] In step S11, the control unit 45 switches the shooting mode of the rear camera 30 to telephoto mode. The control unit 45 switches the shooting mode of the rear camera 30 to telephoto mode by transmitting an instruction signal to the rear camera 30 via the communication line 2 using the communication unit 41. When the rear camera 30 receives the instruction signal from the driver assistance device 40 via the communication line 2, it switches the shooting mode to telephoto mode. With this configuration, the display device 20 displays the image of the driver's seat of the pursuing vehicle generated by the rear camera 30. The driver of vehicle 1 can confirm what kind of person the driver of the pursuing vehicle is from the image displayed on the display device 20.

[0037] In step S12, the control unit 45 deactivates the telephoto mode of the rear camera 30. For example, the control unit 45 deactivates the telephoto mode of the rear camera 30 after a set time has elapsed since the rear camera 30 was switched to telephoto mode. The set time may be set based on the time it takes for the driver of vehicle 1 to confirm the driver of the following vehicle. The control unit 45 deactivates the telephoto mode of the rear camera 30 by transmitting a deactivation signal to the rear camera 30 via the communication line 2 using the communication unit 41. When the rear camera 30 receives the deactivation signal from the driver assistance device 40 via the communication line 2, it deactivates the telephoto mode and returns to normal shooting mode.

[0038] Here, in the process of step S4, the control unit 45 may measure the relative speed of the other vehicle with respect to its own vehicle. The control unit 45 may measure the relative speed of the other vehicle with respect to its own vehicle by analyzing the image generated by the rear camera 30. Alternatively, if the vehicle 1 includes a rangefinder, the control unit 45 may measure the relative speed of the other vehicle with respect to its own vehicle using the rangefinder. If the control unit 45 measures the relative speed of the other vehicle with respect to its own vehicle in the process of step S4, it may determine in the process of step S5, based on the measured relative speed, whether the distance between the other vehicle and its own vehicle decreases with the passage of time. If the control unit 45 determines that the distance between the other vehicle and its own vehicle decreases with the passage of time (step S5: YES), it proceeds to the process of step S7. On the other hand, if the control unit 45 does not determine that the distance between the other vehicle and its own vehicle decreases with the passage of time (step S5: NO), it proceeds to the process of step S6.

[0039] Furthermore, if the control unit 45 measures the relative speed of the other vehicle with respect to its own vehicle in step S4, it may determine in step S5 whether the relative speed is greater than or equal to a predetermined value. The predetermined value may be set considering the relative speed of the other vehicle with respect to its own vehicle when the other vehicle is following it. If the control unit 45 determines that the relative speed of the other vehicle with respect to its own vehicle is greater than or equal to the predetermined value (step S5: YES), it proceeds to step S7. On the other hand, if the control unit 45 determines that the relative speed of the other vehicle with respect to its own vehicle is less than the predetermined value (step S5: NO), it proceeds to step S6.

[0040] Furthermore, the control unit 45 may execute the process in step S4 if the other vehicle determined to have changed lanes in step S2 is driving directly behind the self-driving vehicle after changing lanes. In other words, if the other vehicle determined to have changed lanes in step S2 is not driving directly behind the self-driving vehicle after changing lanes, the control unit 45 may not proceed to step S4 and terminate the process of the driving assistance method. For example, if there is another vehicle between the other vehicle determined to have changed lanes and the self-driving vehicle, the control unit 45 may not proceed to step S4 and terminate the process of the driving assistance method.

[0041] In the driver assistance device 40 according to this embodiment, the control unit 45 determines whether or not another vehicle following the vehicle is following the vehicle if that vehicle changes lanes into the same lane as the vehicle within a predetermined time after detecting the vehicle's lane change. With this configuration, it is possible to determine whether or not another vehicle is following the vehicle even if it was not traveling directly behind the vehicle before the vehicle changed lanes. For example, it is possible to determine whether or not vehicle 3, as shown in Figure 3, is following the vehicle. Therefore, in this embodiment, it is possible to determine whether or not other vehicles are following the vehicle even if they are not continuously following directly behind the vehicle. Thus, in this embodiment, it is possible to detect other vehicles following the vehicle more reliably.

[0042] Furthermore, in passing lanes, when another vehicle overtakes your vehicle, the other vehicle approaches from behind while increasing its speed. Therefore, if you detect the state of the other vehicle behind your vehicle and determine whether or not the other vehicle is following your vehicle, you may mistakenly determine that the other vehicle is following your vehicle even if it is simply overtaking you. In this embodiment, the control unit 45 detects your vehicle's lane change and then, when the other vehicle changes lanes into the same lane as your vehicle, it determines whether or not the other vehicle is following your vehicle. With this configuration, it is possible to suppress the mistaken determination that another vehicle is following your vehicle when it is simply overtaking you.

[0043] Furthermore, if another vehicle is following your vehicle, there is a high probability that the other vehicle will also change lanes to the same lane as your vehicle when your vehicle changes lanes. In this embodiment, the control unit 45 determines whether or not the other vehicle is following your vehicle when it changes lanes to the same lane as your vehicle. With this configuration, in this embodiment, it is possible to more reliably detect other vehicles that are following your vehicle.

[0044] Therefore, according to this embodiment, the technology for detecting other vehicles that are following one's own vehicle can be improved.

[0045] Furthermore, in this embodiment, if the control unit 45 determines that another vehicle is following the vehicle, it may notify the driver of the vehicle of the presence of the following vehicle. Here, when a driver changes lanes on an expressway or highway, they rarely look in their rearview mirror immediately after changing lanes. Therefore, even if there is another vehicle following the vehicle immediately after changing lanes, the driver often does not notice the presence of the other vehicle. In this embodiment, when the control unit 45 determines that another vehicle is following the vehicle after it changes lanes into the same lane as the vehicle, it notifies the driver of the vehicle of the presence of the following vehicle. With this configuration, the driver of vehicle 1 can become aware of the presence of another vehicle if there is another vehicle following the vehicle immediately after changing lanes.

[0046] While this disclosure has been described based on the drawings and embodiments, it should be noted that those skilled in the art may make various modifications and alterations based on this disclosure. Therefore, it should be noted that these modifications and alterations are within the scope of this disclosure. For example, the functions, etc., included in each component or step can be rearranged in a logically consistent manner, and multiple components or steps can be combined into one or divided into two. [Explanation of symbols]

[0047] 1: Vehicle, 2: Communication line, 3: Vehicle, 4: Vehicle, 10: Electronic control unit, 20: Display device, 30: Rear camera, 40: Driving assistance device, 41: Communication unit, 42: Input unit, 43: Output unit, 44: Memory unit, 45: Control unit

Claims

1. The system includes a control unit that determines whether or not another vehicle following the vehicle is following the vehicle if, within a predetermined time after detecting the vehicle's lane change, another vehicle behind the vehicle changes lanes into the same lane as the vehicle. The control unit, If the distance between the other vehicle and the self-vehicle decreases over time, it is determined that the other vehicle is tracking the self-vehicle. A driver assistance device that, when it is determined that the aforementioned other vehicle is following the aforementioned vehicle, notifies the driver of the aforementioned vehicle of the presence of the following vehicle.

2. The driving assistance device according to claim 1, wherein the control unit determines that the other vehicle is following the vehicle, and switches the shooting mode of the vehicle's rear camera to telephoto mode.

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