Warning device and warning method

Abstract

To reduce a risk of notification to a crew member being accidentally suppressed.SOLUTION: A warning device that warns a crew member of a vehicle 100 comprises: a moving object detection unit 331 that detects a moving object behind the vehicle based on output data of a sensor; a stationary object detection unit 332 that detects a stationary object behind the vehicle based on output data from the sensor; and a warning unit 334 that warns the crew member of the vehicle when the moving object is expected to approach the vehicle and arrive in front of a door of the vehicle. Even when the moving object is expected to approach the vehicle and arrive in front of the door of the vehicle, the warning unit suppresses the warning when the stationary object is detected to be in front of the moving object; and even when the stationary object is detected to be in front of the moving object, the warning unit does not suppress the warning when the stationary object is another vehicle and is a projection portion that projects in a vehicle width direction.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a warning device and a warning method. [Background technology]

[0002] There is known a device that detects other vehicles around a vehicle and, if the detected other vehicle is approaching the vehicle, notifies the occupant of the approaching other vehicle (Patent Documents 1 and 2). In particular, in the device described in Patent Document 1, when a sensor that detects an object located behind the vehicle detects an approaching vehicle, the device notifies the occupant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-163805 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-045838 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if there is a stationary object, such as a parked vehicle, behind the vehicle, the sensor may mistakenly detect the object due to reflection from the stationary object. Therefore, in this case, it is possible to suppress notification to the occupant when an object is detected. However, in this case, there is a possibility that notification to the occupant may be suppressed even if a real object is detected through, for example, the outer mirror of the parked vehicle.

[0005] In view of the above-mentioned problems, an object of the present disclosure is to reduce the erroneous suppression of notification to occupants. [Means for solving the problem]

[0006] The gist of the present disclosure is as follows.

[0007] (1) A warning device that warns vehicle occupants, a moving object detection unit that detects a moving object behind the vehicle based on output data from a sensor; a stationary object detection unit that detects a stationary object behind the vehicle based on output data from the sensor; a warning unit that issues a warning to an occupant of the vehicle when the moving object is expected to approach the vehicle and arrive in front of a door of the vehicle, The warning unit suppresses the warning when it is detected that the stationary object is located in front of the moving object, even if the moving object is expected to approach the vehicle and arrive in front of the door of the vehicle, and does not suppress the warning when it is detected that the stationary object is located in front of the moving object and the stationary object is another vehicle and is a protruding part protruding in the vehicle width direction, even if it is detected that the stationary object is located in front of the moving object. (2) A warning method for warning a vehicle occupant, comprising: Detecting a moving object behind the vehicle based on output data from the sensor; detecting a stationary object behind the vehicle based on output data from the sensor; and issuing a warning to an occupant of the vehicle when the moving object is expected to approach the vehicle and arrive in front of a door of the vehicle, A warning method in which, even if the moving object is expected to approach the vehicle and arrive in front of the door of the vehicle, the warning is suppressed when it is detected that the stationary object is located in front of the moving object, and the warning is not suppressed when the stationary object is another vehicle and is a protruding part protruding in the vehicle width direction, even if it is detected that the stationary object is located in front of the moving object. [Effects of the Invention]

[0008] According to the present disclosure, the erroneous suppression of notification to the occupant is reduced. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram showing a warning system in which a warning device is implemented. [Figure 2] FIG. 2 is a diagram showing the arrangement of sensors provided in a vehicle. [Figure 3] FIG. 3 is a functional block diagram of the processor of the ECU. [Figure 4] FIG. 4 is a diagram showing an example in which another vehicle is parked behind a parked vehicle and a motorcycle is traveling around the vehicle. [Figure 5] FIG. 5 is a flowchart showing the flow of the warning process. [Figure 6] FIG. 6 is a diagram showing another vehicle positioned behind the vehicle. [Figure 7] FIG. 7 is a view similar to FIG. 6, showing another vehicle positioned behind the vehicle. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the embodiments will be described in detail with reference to the drawings. In the following description, like components are designated by like reference numerals.

[0011] <Warning system configuration> The configuration of a warning system 1 equipped with a warning device will be described with reference to Figures 1 and 2. Figure 1 is a schematic diagram of the warning system 1 in which a warning device according to one embodiment is implemented. Figure 2 is a diagram showing the arrangement of sensors provided in a vehicle 100. The warning system 1 is mounted on the vehicle 100 and issues a warning to the occupants of the vehicle 100. In particular, the warning system 1 issues a warning to the occupants of the vehicle 100 when a moving object is approaching the vehicle 100 and is expected to arrive in front of the door of the vehicle 100.

[0012] 1, the warning system 1 includes a millimeter-wave radar 11, an ultrasonic sensor 12, an exterior camera 13, a vehicle speed sensor 14, a human-machine interface (HMI) 15, a door actuator 21, and an electronic control unit (hereinafter referred to as "ECU") 30. The millimeter-wave radar 11, the ultrasonic sensor 12, the exterior camera 13, the vehicle speed sensor 14, the HMI 15, and the ECU 30 are communicatively connected, for example, via an in-vehicle network 20. The in-vehicle network 20 is, for example, a network that complies with a standard such as CAN (Controller Area Network). The ECU 30 is also connected to the door actuator 21 via a signal line.

[0013] 1, the ECU 30 is formed as a separate entity from the millimeter-wave radar 11, the ultrasonic sensor 12, and the exterior camera 13. However, at least one of the millimeter-wave radar 11, the ultrasonic sensor 12, and the exterior camera 13 may be incorporated into the ECU 30 and formed integrally with the ECU 30. Also, in the example shown in FIG. 1, the ECU 30 is formed as a separate entity from the speaker 17. However, the speaker 17 may be incorporated into the ECU 30 and formed integrally with the ECU 30.

[0014] The millimeter-wave radar 11 is an example of a sensor that detects the distance to an object (body) around the vehicle 100. The millimeter-wave radar 11 can also detect the direction in which the object around the vehicle 100 is located relative to the vehicle 100, and the relative speed of the object with respect to the vehicle 100. As shown in Fig. 2, in this embodiment, one millimeter-wave radar 11 is provided on the left and right rear of the vehicle 100, and detects an object located on the left rear of the vehicle 100 and an object located on the right rear of the vehicle 100, respectively.

[0015] The millimeter-wave radar 11 transmits radio waves from a transmitting antenna and receives reflected waves from a receiving antenna. The millimeter-wave radar 11 measures the distance to an object based on the time between transmitting the radio waves from the transmitting antenna and receiving the reflected waves. In addition, the millimeter-wave radar 11 measures the orientation of the object relative to the millimeter-wave radar 11 based on the time difference between the reception of reflected waves by multiple receiving antennas arranged side by side. The millimeter-wave radar 11 mixes the radio waves transmitted from the transmitting antenna and the reflected waves received by the receiving antenna, performs signal processing, and generates output data related to the position information of the object and outputs it to the ECU 30.

[0016] The ultrasonic sensor 12 is an example of a sensor that detects the distance to an object (body) around the vehicle 100. The ultrasonic sensor 12 can also detect the direction in which an object around the vehicle 100 is located relative to the vehicle 100 and the relative speed of the object with respect to the vehicle 100. The ultrasonic sensor 12 uses ultrasonic waves instead of millimeter waves, and generates output data related to the position information of the object, similar to the millimeter-wave radar 11, and outputs the output data to the ECU 30.

[0017] The ultrasonic sensor 12 has a narrow detection range. Therefore, as shown in Fig. 2, the ultrasonic sensors 12 are provided on the vehicle 100 at closer intervals than the millimeter-wave radar 11. In this embodiment, four ultrasonic sensors 12 are provided at the rear of the vehicle 100 at intervals in the vehicle width direction. The ultrasonic sensors 12 are also provided below the millimeter-wave radar 11, and therefore detect the distance to an object vertically below the millimeter-wave radar 11.

[0018] In this embodiment, a millimeter-wave radar 11 and an ultrasonic sensor 12 are provided as sensors for detecting distances to objects around the vehicle 100. However, other sensors including other radars such as laser radar (LiDAR) may also be used as such sensors. Laser radar is a sensor that measures the reflected light of a pulsed laser beam emitted to measure the position of an object within a measurement range.

[0019] The exterior camera 13 is an example of a sensor that captures images of the surroundings of the vehicle 100. In this embodiment, the exterior camera 13 is arranged behind the vehicle 100 (inside the rear window) as shown in FIG. 2 and captures images of the area behind the vehicle 100. The exterior camera 13 is, for example, a CMOS camera or a CCD camera that is sensitive to visible light. The exterior camera 13 captures images of the area behind the vehicle 100 at predetermined imaging intervals and generates image data (output data) showing the area behind the vehicle 100. The exterior camera 13 may be a monocular camera or a stereo camera. The exterior camera 13 does not have to be provided in the warning system 1.

[0020] The vehicle speed sensor 14 is an example of a sensor that detects the speed of the vehicle 100. The vehicle speed sensor 14 detects, for example, the rotation speed of the wheels of the vehicle 100. The vehicle speed sensor 14 generates output data related to the speed of the vehicle 100 and outputs the data to the ECU 30.

[0021] The HMI 15 is an interface for inputting and outputting information between the driver or passenger and the warning system 1. The HMI 15 includes an information providing device for providing various information to the driver or passenger, and an input device for the driver or passenger to perform input operations.

[0022] Specifically, the HMI 15, as an information providing device, includes a display 16 for displaying text information and image information. The display 16 is an example of a display device that displays images. The display 16 is a display device of any type, such as a liquid crystal display or an organic EL display. The display 16 is disposed, for example, on an instrument panel, meter panel, or the like of the vehicle 100. The display 16 receives an image signal from the ECU 30 via the in-vehicle network 20 and displays an image in accordance with the image signal.

[0023] The HMI 15 also has a speaker 17 as an information providing device. The speaker 17 is an example of a device that outputs audio. The speaker 17 receives an audio signal from the ECU 30 via the in-vehicle network 20 and outputs audio in accordance with this audio signal. Note that the HMI 15 may also include devices (e.g., a vibration device) other than the display 16 and the speaker 17 as an information providing device that provides various types of information to the driver or passengers.

[0024] The door actuator 21 controls the state of the doors of the vehicle 100. The door actuator 21 is provided in each door and controls the state of each door in accordance with a control signal transmitted from the ECU 30 via a signal line. The door actuator 21 controls, for example, the locking of the doors of the vehicle 100.

[0025] <Configuration of warning device> The ECU 30 functions as a warning device that warns an occupant of the vehicle 100. The ECU 30 also executes a warning method for warning an occupant of the vehicle 100. As shown in FIG. 2 , the ECU 30 includes a communication interface 31, a storage unit 32, and a processor 33.

[0026] The communication interface 31 is a circuit for connecting the ECU 30 to the in-vehicle network 20 .

[0027] The storage unit 32 is an example of a non-transitory storage medium for storing data. The storage unit 32 includes, for example, at least one of a volatile semiconductor memory, a non-volatile semiconductor memory, a hard disk drive (HDD), and a solid state drive (SSD). The storage unit 32 stores computer programs executed by the processor 33 of the ECU 30. The storage unit 32 also stores data used in the computer programs executed by the processor 33, such as data transmitted from various sensors.

[0028] The processor 33 has one or more central processing units (CPUs) and their peripheral circuits. The processor 33 may further have other arithmetic circuits such as a logic operation unit or a numerical operation unit. The processor 33 executes various processes based on computer programs stored in the storage unit 32.

[0029] 3 is a functional block diagram of the processor 33 of the ECU 30. As shown in FIG. 3, the processor 33 includes a moving object detection unit 331, a stationary object detection unit 332, an approach prediction unit 333, and a warning unit 334. Each of these units included in the processor 33 is a functional module realized by, for example, a computer program running on the processor 33. Alternatively, each unit included in the processor 33 may be implemented in the ECU 30 as an independent integrated circuit, microprocessor, or firmware.

[0030] The moving object detection unit 331 detects a moving object behind the vehicle 100 based on output data from the sensors. In this embodiment, the moving object detection unit 331 detects a moving object based on output data from the millimeter wave radar 11 or the ultrasonic sensor 12. In addition, the moving object detection unit 331 may detect a moving object based on output data from the outside camera 13.

[0031] Specifically, when a change in the distance or orientation of an object around the vehicle 100 is detected based on the time-series output data of the millimeter-wave radar 11 or the ultrasonic sensor 12, the moving object detection unit 331 detects the object as a moving object. For example, the moving object detection unit 331 sequentially inputs the time-series output data of the millimeter-wave radar 11 or the ultrasonic sensor 12 to a classifier, thereby outputting position information of the moving objects around the vehicle 100 (such as the relative position and relative speed with respect to the vehicle 100). The classifier is, for example, a recurrent neural network (RNN) to which time-series data is sequentially input.

[0032] The moving object detection unit 331 may also detect objects around the vehicle 100 based on output data from the exterior camera 13, and identify the type of the detected moving object based on output data from the millimeter-wave radar 11 or the ultrasonic sensor 12. The moving object detection unit 331, for example, sequentially inputs image data captured by the exterior camera 13 into a classifier to detect the type of object (e.g., pedestrian, bicycle, motorbike, automobile, etc.) depicted in each image and the area within the image in which the object is depicted. The classifier is, for example, a convolutional neural network (CNN) having multiple convolution layers connected in series from the input side to the output side. Additionally, the moving object detection unit 331 identifies the type of each moving object based on the area of ​​the object depicted in each image of the image data and the position information of the moving object detected based on data received from the millimeter-wave radar 11 or the ultrasonic sensor 12. Therefore, the moving object detection unit 331 outputs the type of each moving object around the vehicle 100 and the position information of the moving object.

[0033] In this embodiment, the moving object detection unit 331 detects moving objects around the vehicle 100 based on the output data of the outside camera 13 in addition to the output data of the millimeter-wave radar 11 and the ultrasonic sensor 12. However, the moving object detection unit 331 may detect moving objects based only on the millimeter-wave radar 11 or only on the ultrasonic sensor 12, or may detect moving objects based only on the output data of the outside camera 13.

[0034] The stationary object detection unit 332 detects stationary objects behind the vehicle 100 based on output data from the sensors. In this embodiment, the stationary object detection unit 332 detects stationary objects based on output data from the exterior camera 13. In addition, the stationary object detection unit 332 may detect stationary objects based on output data from the millimeter-wave radar 11 or the ultrasonic sensor 12.

[0035] Similar to the moving object detection unit 331, the stationary object detection unit 332 detects objects around the vehicle 100 based on the output data of the exterior camera 13. For example, the stationary object detection unit 332 sequentially inputs the data of images captured by the exterior camera 13 to a classifier, thereby detecting the type of object shown in each image and its shape (for example, if the image shows a vehicle, the position and size of the outer mirrors in addition to the shape of the vehicle body). The classifier is, for example, a convolutional neural network (CNN).

[0036] Furthermore, the stationary object detection unit 332 may determine whether or not an object (stationary object) around the vehicle 100 is stationary based on the time-series output data of the millimeter-wave radar 11 or the ultrasonic sensor 12, and may output its position information if it is stationary. Therefore, the stationary object detection unit 332 may output position information of stationary objects around (behind) the vehicle 100 based on information about the type of object around the vehicle 100 detected based on the output data of the exterior camera 13 and the position information of the target object around the vehicle 100.

[0037] The approach prediction unit 333 predicts whether a moving object detected by the moving object detection unit 331 will approach the vehicle 100 and arrive in front of a door of the vehicle 100 (particularly, whether the moving object will arrive at a position where it will collide with the door if the door is open). In this embodiment, the approach prediction unit 333 predicts whether a moving object detected by the moving object detection unit 331 will arrive in front of a door of the vehicle 100 based on position information of the moving object detected by the moving object detection unit 331 (particularly, a relative position and relative speed with respect to the vehicle 100). For example, based on the position information of the moving object detected by the moving object detection unit 331, the approach prediction unit 333 predicts whether the moving object will arrive in front of the door of the vehicle 100 within a predetermined reference time, assuming that the moving object moves at the same relative speed. The reference time may be a predetermined fixed time, or may be a time that changes depending on the value of an arbitrary parameter, such as the moving speed of the detected moving object.

[0038] The warning unit 334 basically issues a warning to the occupants of the vehicle 100 when the approach prediction unit 333 predicts that a moving object will arrive in front of the door of the vehicle 100. For example, when the warning unit 334 predicts that a moving object will arrive in front of the door of the vehicle 100 within a reference time, the warning unit 334 warns the occupants of the vehicle 100 that the moving object is expected to arrive in front of the door. Specifically, in such a case, the warning unit 334 displays on the display 16 a message that the moving object is expected to arrive in front of the door, and outputs a sound to that effect from the speaker 17.

[0039] Furthermore, when the approach prediction unit 333 predicts that a moving object will arrive in front of a door of the vehicle 100, the warning unit 334 may restrict the opening of the door. Specifically, for example, when the approach prediction unit 333 predicts that a moving object will arrive in front of a door of the vehicle 100, the warning unit 334 controls the door actuator 21 of the door so that the door is not opened.

[0040] <Control when there are protrusions> 4A and 4B show an example in which another vehicle X is parked behind a parked vehicle 100 and a motorcycle Y is traveling around the vehicle 100. Fig. 4A shows a case in which the motorcycle Y is traveling to the side of the vehicle 100, and Fig. 4B shows a case in which the motorcycle Y is traveling to the right rear of the vehicle 100.

[0041] Here, if the radio waves emitted from the millimeter-wave radar 11 are reflected by the front of another vehicle X parked behind the vehicle 100, the millimeter-wave radar 11 cannot necessarily properly calculate the position information of the moving object. In the example shown in FIG. 4(A), the radio waves emitted from the millimeter-wave radar 11 (and the reflected waves reflected by the motorcycle Y) are reflected by the front of the other vehicle X. For this reason, even though the motorcycle Y is traveling beside the vehicle 100 in a direction moving rearward away from the vehicle 100, it may be determined that the motorcycle is traveling behind the vehicle 100 in a direction approaching the vehicle 100. In the example shown in FIG. 4(A), it may be erroneously determined that the motorcycle is located at position Y' in the figure and traveling in a direction approaching the vehicle 100.

[0042] Therefore, in this embodiment, even if the approach prediction unit 333 predicts that a moving object will approach the vehicle 100 and arrive in front of the door of the vehicle 100, the warning unit 334 suppresses the warning to the occupant when it is determined that the stationary object detected by the stationary object detection unit 332 is located in front of the moving object. In the example shown in Fig. 4(A), the vehicle X, which is a stationary object detected by the stationary object detection unit 332, is located in front of the virtual motorcycle Y', which is a moving object detected by the moving object detection unit 331, and therefore the warning unit 334 suppresses the warning to the occupant.

[0043] In this embodiment, in such a case, the warning unit 334 does not warn the occupant, nor does it control the door actuator 21 to prevent the door from opening. However, the warning unit 334 may suppress warning the occupant by other methods. For example, in this embodiment, the warning unit 334 displays on the display 16 a message that a moving object is expected to arrive in front of the door and outputs a sound to that effect from the speaker 17. However, if it is detected that a stationary object is located in front of the moving object, the warning unit 334 may perform only one of these actions. Furthermore, if it is detected that a stationary object is located in front of the moving object, the warning unit 334 may lower the volume of the sound output from the speaker 17 compared to when it is not detected.

[0044] On the other hand, as shown in Fig. 4(B), when a protruding portion of a stationary object (for example, an outer mirror of a vehicle or a cargo protruding to the side from the vehicle) is located in front of the moving object, the warning unit 334 will determine that the stationary object detected by the stationary object detection unit 332 is located in front of the moving object. However, in the example shown in Fig. 4(B), the moving object, motorcycle Y, is actually present to the right rear of the vehicle 100, and motorcycle Y has not been erroneously detected as being present.

[0045] Therefore, in this embodiment, when the approach prediction unit 333 predicts that a moving object will approach the vehicle 100 and arrive in front of the door of the vehicle 100, even if the stationary object detected by the stationary object detection unit 332 is determined to be located in front of the moving object, if the stationary object located in front of the moving object is a protruding portion protruding in the vehicle width direction from the other vehicle X, the warning unit 334 does not suppress the warning to the occupant. In the example shown in FIG. 4(B), the stationary object detected to be located in front of the motorcycle Y is a protruding portion of the other vehicle X (an outer mirror of the other vehicle X), so the warning unit 334 does not suppress the warning to the occupant. Therefore, the warning unit 334 displays on the display 16 a message that a moving object is expected to arrive in front of the door and outputs a sound to that effect from the speaker 17. In addition, the warning unit 334 controls the door actuator 21 to prevent the door from opening.

[0046] As a result, when a protruding stationary object is located in front of an actual moving object as shown in Fig. 4(B), it is possible to prevent the system from erroneously determining that a moving object has been detected and not issuing a warning to the occupant, thereby reducing the possibility of erroneously suppressing notification to the occupant.

[0047] <Warning process flow> Next, a flow of a warning process for warning an occupant of the vehicle 100 will be described with reference to Fig. 5. Fig. 5 is a flowchart showing the flow of the warning process. The warning process shown in Fig. 5 is executed by the processor 33 of the ECU 30.

[0048] When the warning process is started, the warning unit 334 determines whether the vehicle 100 is stopped or not (step S11). Whether the vehicle 100 is stopped or not is determined based on the output data of the vehicle speed sensor 14. If the vehicle 100 is not stopped, the doors of the vehicle 100 will not be opened, and therefore, even if a moving object arrives in front of the door of the vehicle 100, there is no need to warn the occupants. Therefore, if it is determined in step S11 that the vehicle 100 is not stopped, the warning process is terminated.

[0049] On the other hand, if it is determined in step S11 that the vehicle 100 is stopped, the moving object detection unit 331 detects a moving object behind the vehicle 100, and the stationary object detection unit 332 detects a stationary object behind the vehicle 100 (step S12). In this embodiment, the moving object detection unit 331 and the stationary object detection unit 332 detect the moving object and the stationary object, respectively, based on the output data of the millimeter-wave radar 11, the ultrasonic sensor 12, and the exterior camera 13. In this embodiment, the moving object detection unit 331 detects the relative position and relative speed of moving objects around the vehicle 100 with respect to the vehicle 100. Furthermore, the stationary object detection unit 332 detects the relative position of stationary objects around the vehicle 100 with respect to the vehicle 100, the shape of the stationary object, and the type of the stationary object. In addition, the stationary object detection unit 332 detects protruding parts of stationary objects based on the output data of the exterior camera 13. In this embodiment, the stationary object detection unit 332 detects the shape of a stationary object (such as another vehicle) located behind the vehicle 100 based on the output data of the exterior camera 13, and detects the position of a protruding part of the stationary object based on the shape of the stationary object. Alternatively, the stationary object detection unit 332 may detect the position of a protruding part of the stationary object based on the shape of the stationary object detected based on the output data of the exterior camera 13 and position information of the stationary object detected based on the output data of the millimeter-wave radar 11 or the ultrasonic sensor 12.

[0050] Next, the approach prediction unit 333 determines whether or not the moving object detected in step S12 is approaching the vehicle 100 (step S13). In this embodiment, the approach prediction unit 333 determines whether or not the moving object is approaching the vehicle 100 based on the relative speed of the moving object with respect to the vehicle 100. If it is determined in step S13 that the moving object is not approaching the vehicle 100, the warning process is terminated.

[0051] If it is determined in step S13 that the moving object is approaching the vehicle 100, the approach prediction unit 333 determines whether or not the moving object determined to be approaching in step S13 is located to the side or behind the vehicle 100 (step S14). In this embodiment, the approach prediction unit 333 determines whether or not the moving object is located to the side or behind the vehicle 100 based on the relative position of the moving object with respect to the vehicle 100. If it is determined in step S14 that the moving object is not located to the side or behind the vehicle 100, the warning process is terminated.

[0052] If it is determined in step S14 that the moving object is located to the side or rear of the vehicle 100, the approach prediction unit 333 determines whether or not the moving object determined in step S14 to be located to the side or rear of the vehicle 100 is expected to arrive in front of the door of the vehicle 100 (step S15). In this embodiment, the approach prediction unit 333 determines whether or not the moving object is expected to arrive in front of the door of the vehicle 100 based on the relative position and relative speed of the moving object with respect to the vehicle 100. If it is determined in step S15 that the moving object is not expected to arrive in front of the door of the vehicle 100, the warning process is terminated.

[0053] If it is determined in step S15 that the moving object is expected to arrive in front of the door of the vehicle 100, the warning unit 334 determines whether or not a stationary object detected by the stationary object detection unit 332 is located in front of the moving object detected in step S12 (step S16). In this embodiment, the warning unit 334 determines whether or not a stationary object is located in front of the moving object based on the relative position of the stationary object with respect to the vehicle 100 and the shape of the stationary object.

[0054] If it is determined in step S16 that no stationary object is located in front of the moving object, the warning unit 334 issues a normal warning to the occupants of the vehicle 100 that a moving object is expected to arrive in front of the door (step S17). Specifically, the warning unit 334 displays on the display 16 a message that a moving object is expected to arrive in front of the door, and outputs a sound to that effect from the speaker 17.

[0055] On the other hand, if it is determined in step S16 that a stationary object is located in front of the moving object, the warning unit 334 determines whether or not the stationary object determined to be located in front of the moving object in step S16 is another vehicle (step S18). In this embodiment, the warning unit 334 determines whether or not the stationary object is another vehicle based on the type of the stationary object detected by the stationary object detection unit 332. If it is determined in step S18 that the stationary object is not another vehicle, the warning unit 334 issues a normal warning (step S17).

[0056] If it is determined in step S18 that the stationary object is a vehicle, the warning unit 334 determines whether or not the stationary object located in front of the moving object is a protruding part of the stationary object determined to be another vehicle in step S16 (step S19). In this embodiment, the warning unit 334 determines whether or not the position of the protruding part of the stationary object detected by the stationary object detection unit 332 is in front of the position of the moving object detected by the moving object detection unit 331. Note that in this embodiment, if both a protruding part of the stationary object and a part that is not a protruding part of the stationary object are located in front of the moving object, the warning unit 334 determines that the stationary object located in front of the moving object is not a protruding part of the stationary object because it includes a part that is not a protruding part of the stationary object.

[0057] If it is determined in step S19 that the stationary object located in front of the moving object is not a protruding part of another vehicle, the warning unit 334 issues a normal warning (step S17). On the other hand, if it is determined in step S19 that the stationary object located in front of the moving object is a protruding part of another vehicle, the warning unit 334 limits the warning to the occupants of the vehicle 100 (step S20).

[0058] <Modification> Next, a modified example will be described with reference to Figures 6 and 7. In one modified example, the stationary object detection unit 332 detects a stationary object based on output data from the millimeter wave radar 11 and the ultrasonic sensor 12.

[0059] 6 is a diagram showing another vehicle X located behind the vehicle 100. As described above, the measurement range of the ultrasonic sensor 12 is located lower than that of the millimeter-wave radar 11. Therefore, as shown in FIG. 6, the millimeter-wave radar 11 can measure distance and the like in the region Hr in the figure, whereas the ultrasonic sensor 12 measures distance and the like in the region Hs lower than the region Hr. As a result, the millimeter-wave radar 11 performs measurements in the height region where the protrusion (outer mirror) Xm is located, whereas the ultrasonic sensor 12 does not perform measurements in the height region where the protrusion (outer mirror) Xm is located.

[0060] Therefore, in this modification, when the shape of the other vehicle X (stationary object) detected by the millimeter-wave radar 11 protrudes in the vehicle width direction of the other vehicle X more than the shape of the other vehicle X (stationary object) detected by the ultrasonic sensor 12, the stationary object detection unit 332 detects the protruding portion as a protruding part. Therefore, in the example shown in FIG. 6 , the stationary object detection unit 332 detects a region Wp in the vehicle width direction as a region where the protruding part Xm of the other vehicle X is located. On the other hand, the stationary object detection unit 332 detects a region Ws in the vehicle width direction as a region of the other vehicle X where the protruding part Xm is not located. This allows the stationary object detection unit 332 to detect a protruding part without using output data from the exterior camera 13.

[0061] Another modified example will be described with reference to FIG. 7. In this modified example, the stationary object detection unit 332 detects stationary objects based on output data from a laser radar (LiDAR) used instead of the millimeter-wave radar 11. In this modified example, the laser radar emits laser light at multiple different angles in the vertical and horizontal directions, and measures the distance to the object at each angle based on the reflected light of the laser light. Therefore, the laser radar measures the distance to the object at multiple measurement points in the vertical and horizontal directions. FIG. 7 is a diagram similar to FIG. 6, showing another vehicle X located behind the vehicle 100. The black circles in the diagram represent measurement points where the radar measures the distance and where an object is detected to be located near the front of the vehicle X.

[0062] In this modification, when a stationary object is measured at a similar distance from multiple measurement points aligned in the vertical direction, i.e., when it is detected that the vertical width of the object is equal to or greater than a certain width, the stationary object detection unit 332 determines that another vehicle X (stationary object) is located at that position. Then, the stationary object detection unit 332 estimates the position of the row of measurement points at the end in the horizontal direction (A in the figure) among the rows of measurement points at which an object has been detected at multiple measurement points aligned in the vertical direction as the position of the end in the width direction of the other vehicle X. Note that, if the stationary object detection unit 332 can detect the position of the tire of the other vehicle X, for example, based on the point cloud data of the radar measurement points, it may estimate the outer position of the tire as the position of the end in the width direction of the other vehicle X.

[0063] In addition, if an object is detected at a measurement point that is outside the calculated widthwise end of the other vehicle X, the stationary object detection unit 332 determines that a protruding portion of the other vehicle X (such as an outer mirror or a cargo object) is located at the position of this measurement point. However, even in such a case, if there are more than a certain number of measurement points where the object has been detected lined up in the vertical direction, that is, if the vertical width of the object is greater than a predetermined reference width, the stationary object detection unit 332 does not determine that a protruding portion is located. Therefore, in the example shown in FIG. 7(B), since the vertical width of the object is greater than the reference width Ref, it is determined that no protruding portion exists in the region Zb in the figure.

[0064] On the other hand, if a certain number or fewer measurement points where an object is detected are aligned vertically, i.e., if the vertical width of the object is equal to or less than a predetermined reference width, the stationary object detection unit 332 determines that a protrusion is located at the position of these measurement points. Therefore, the stationary object detection unit 332 detects a protrusion of an object at a location where another object is detected by radar and where the vertical width of the object is detected to be equal to or less than the predetermined reference width on the side of the object. In the example shown in FIG. 7(a), since the vertical width of the object is equal to or less than the reference width Ref, it is determined that the protrusion is located in the area Za in the figure. This allows the stationary object detection unit 332 to detect a protrusion without using the output data of the ultrasonic sensor 12 in addition to the external camera 13.

[0065] Although preferred embodiments according to the present disclosure have been described above, the present disclosure is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims. [Explanation of symbols]

[0066] 1. Warning System 11 Millimeter wave radar 12 Ultrasonic Sensor 13. Exterior camera 15 HMI 30 ECU 33 processors 100 vehicles

Claims

1. A warning device for warning a vehicle occupant, a moving object detection unit that detects a moving object behind the vehicle based on output data from a sensor; a stationary object detection unit that detects a stationary object behind the vehicle based on output data from the sensor; a warning unit that issues a warning to an occupant of the vehicle when the moving object is expected to approach the vehicle and arrive in front of a door of the vehicle, The warning unit suppresses the warning when it is detected that the stationary object is located in front of the moving object, even if the moving object is expected to approach the vehicle and arrive in front of the door of the vehicle, and does not suppress the warning when it is detected that the stationary object is located in front of the moving object and the stationary object is another vehicle and is a protruding part protruding in the vehicle width direction, even if it is detected that the stationary object is located in front of the moving object.

2. 2. The warning device according to claim 1, wherein the detection of the protruding portion of the stationary object by the stationary object detection unit is performed based on output data from an external camera that captures an image behind the vehicle.

3. the detection of a stationary object by the stationary object detection unit is performed based on output data of a radar and an ultrasonic sensor that detect a distance to an object behind the vehicle; the ultrasonic sensor detects a distance to an object behind the vehicle at a position vertically below the radar, 2. The warning device according to claim 1, wherein, when the shape of the vehicle detected by the radar protrudes in a vehicle width direction of the vehicle more than the shape of the vehicle detected by the ultrasonic sensor, the stationary object detection unit detects the protruding portion as a protruding portion.

4. the detection of a stationary object by the stationary object detection unit is performed based on output data of a radar that detects a distance to an object behind the vehicle, 2. The warning device according to claim 1, wherein the stationary object detection unit detects that a protruding portion of the object is located at a location where another object is detected by the radar and where a vertical width of the other object on the side of the other object is detected to be equal to or less than a predetermined width.

5. A warning method for warning an occupant of a vehicle, comprising: Detecting a moving object behind the vehicle based on output data from the sensor; detecting a stationary object behind the vehicle based on output data from the sensor; and issuing a warning to an occupant of the vehicle when the moving object is expected to approach the vehicle and arrive in front of a door of the vehicle, A warning method in which, even if the moving object is expected to approach the vehicle and arrive in front of the door of the vehicle, the warning is suppressed when it is detected that the stationary object is located in front of the moving object, and the warning is not suppressed when the stationary object is another vehicle and is a protruding part protruding in the vehicle width direction, even if it is detected that the stationary object is located in front of the moving object.

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