Vehicle rear monitoring system

Abstract

To obtain a vehicle rear monitoring system capable of suppressing a driver's feeling of oppression when a following vehicle approaches.SOLUTION: A vehicle rear monitoring system includes an imaging unit that captures at least one of the rear and the rear side of an own vehicle, a display unit that is provided in the vehicle interior of the own vehicle and displays a captured image P captured by the imaging unit, and a display control unit makes the display magnification of the captured image P on the display unit smaller than the predetermined display magnification when a distance between a target detected by a target detection unit that detects a target behind the own vehicle and the own vehicle becomes equal to or less than a predetermined threshold value. Therefore, when a following vehicle 60 approaches, the image of the following vehicle 60 displayed on the display unit is zoomed out, and a driver can be prevented from feeling oppressive.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a vehicle rear monitoring system. [Background technology]

[0002] Patent Document 1 discloses a vehicle display device that expands the image range of the rear of the vehicle displayed on the display unit when a turn signal is activated or when a camera mounted inside the vehicle detects that the driver is looking fixedly. By expanding the image range in this way, the driver can reliably see whether there is a following vehicle changing lanes from another vehicle lane, thereby improving the driver's field of vision. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-006936 Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, when a following vehicle approaches the driver's vehicle, the image displayed on the display unit may cause the driver to feel oppressed. However, the technology described in Patent Document 1 uses a change in the image range to assist the driver's field of vision, and there is room for improvement in the display method when a following vehicle is approaching.

[0005] In consideration of the above, an object of the present invention is to provide a vehicle rear monitoring system that can prevent the driver from feeling oppressed when a following vehicle approaches. [Means for solving the problem]

[0006] The vehicle rear monitoring system according to the present invention as set forth in claim 1 includes an imaging unit that captures an image of at least one of the rear and rear lateral sides of the vehicle, and a display unit that is provided in the cabin of the vehicle and displays an image captured by the imaging unit. When a distance between the vehicle and a target detected by a target detection unit that detects a target behind the vehicle is greater than a predetermined threshold, a predetermined area including a center portion of the captured image is displayed on the display unit at a predetermined display magnification; When the distance becomes equal to or less than a predetermined threshold, the display magnification of the captured image on the display unit is The aforementioned Smaller than the preset display magnification The smaller the display magnification, the larger the area of ​​the captured image to be displayed on the display unit. and a display control unit for controlling the display.

[0007] In the vehicle rear monitoring system according to the present invention, the display control unit reduces the display magnification of the captured image on the display unit to a value smaller than a preset display magnification when the distance between the target detected by the target detection unit and the host vehicle becomes equal to or smaller than a predetermined threshold. Therefore, when a following vehicle approaches, the image of the following vehicle displayed on the display unit is zoomed out, thereby reducing the sense of oppression felt by the driver. The vehicle rear monitoring system according to the present invention as set forth in claim 2 has the configuration as set forth in claim 1. ,before The display control unit When the display control unit displays the captured image at a display magnification smaller than the predetermined display magnification, Marks are displayed at the four corners of a predetermined area including the center of the captured image. [Effects of the Invention]

[0008] As described above, the vehicle rear monitoring system according to the present invention has the excellent effect of being able to suppress the driver from feeling oppressed when a following vehicle approaches. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a front part of a vehicle interior of a vehicle to which a vehicle rear monitoring system according to an embodiment of the present invention is applied, viewed from the rear side of the vehicle. [Figure 2] 1 is a block diagram showing a hardware configuration of a vehicle rear monitoring system according to an embodiment of the present invention. [Figure 3] 1 is a block diagram showing a functional configuration of a vehicle display control device according to an embodiment of the present invention; [Figure 4] 3A and 3B are diagrams illustrating an example of a display in a normal state on the display unit according to the present embodiment. [Figure 5] 10A and 10B are diagrams illustrating an example of a display on the display unit when a following vehicle is approaching in this embodiment. [Figure 6] 10 is a flowchart illustrating an example of a processing flow in the present embodiment. [Figure 7] 10A and 10B are diagrams illustrating another example of display on the display unit when a following vehicle is approaching in the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] A vehicle 12 equipped with a vehicle rear monitoring system 10 according to one embodiment of the present invention will be described with reference to the drawings. Note that the arrow UP in Fig. 1 indicates the upper side in the vertical direction of the vehicle, and the arrow RH indicates the right side in the width direction of the vehicle. In the following description, the vertical direction and the left-right direction refer to the up and down in the vertical direction of the vehicle and the left and right in the width direction of the vehicle, respectively.

[0011] As shown in Fig. 1, an instrument panel 14 is provided in the front of a passenger compartment 13 of a host vehicle 12. The instrument panel 14 extends in the vehicle width direction, and a steering wheel 16 is provided on the right side of the instrument panel 14. That is, in this embodiment, as an example, the vehicle is a so-called right-hand drive vehicle in which the steering wheel 16 is provided on the right side, and the driver's seat is located on the right side of the vehicle. A windshield glass 18 is provided at the front end of the instrument panel 14.

[0012] The windshield glass 18 extends from the front end of the instrument panel 14 toward the upper side of the vehicle and separates the interior of the vehicle compartment 13 from the outside of the vehicle interior 13 of the vehicle 12. The right end of the windshield glass 18 is fixed to a front pillar 20 on the right side of the vehicle. The front pillar 20 extends in the vertical direction of the vehicle, and the windshield glass 18 is fixed to the inner end of the front pillar 20 in the vehicle width direction. The front ends of the front side windows 22 are fixed to the outer end of the front pillar 20 in the vehicle width direction. The left end of the windshield glass 18 is fixed to a front pillar on the left side of the vehicle (not shown).

[0013] Here, the instrument panel 14 is provided with a first display unit 24 having an image display area 24A. The first display unit 24 is configured as a meter display provided in front of the driver's seat on the vehicle right side of the instrument panel 14. The first display unit 24 is connected to various meter devices mounted on the vehicle 12, and is provided in a position that is within the field of view of the driver when the driver is looking ahead of the vehicle.

[0014] The instrument panel 14 is provided with a second display unit 25 having an image display area 25A. The second display unit 25 is configured by a center display disposed in the center of the instrument panel 14 in the vehicle width direction.

[0015] The windshield glass 18 is provided with a third display unit 26 having an image display area 26A. The third display unit 26 is set above the vehicle relative to the first display unit 24, and the display area 26A is configured as a projection surface onto which an image is projected by a head-up display (HUD) device 44 (see FIG. 2). Specifically, the head-up display device 44 is provided on the vehicle front side of the instrument panel 14, and an image is projected from this head-up display device 44 onto the display area 26A of the third display unit 26 on the windshield glass 18. In other words, the third display unit 26 is configured as part of the windshield glass 18 that serves as the projection surface for the head-up display device 44.

[0016] (Hardware configuration of vehicle rear monitoring system 10) The host vehicle 12 is equipped with a vehicle rear monitoring system 10. Fig. 2 is a block diagram showing the hardware configuration of the vehicle rear monitoring system 10. As shown in Fig. 2, the vehicle rear monitoring system 10 includes an ECU (Electronic Control Unit) 28 as a display control unit, a first display unit 24, a second display unit 25, a head-up display device 44 and a third display unit 26, an imaging unit 46, a target detection unit 47, a rear confirmation operation unit 48, and in-vehicle equipment 49.

[0017] The ECU 28 includes a CPU (Central Processing Unit: processor) 40A, a ROM (Read Only Memory) 40B, a RAM (Random Access Memory) 40C, a storage 40D, a communication interface (communication I / F) 40E, and an input / output interface (input / output I / F) 40F. Each component is connected to each other via a bus 42 so as to be able to communicate with each other.

[0018] The CPU 40A is a central processing unit that executes various programs and controls each component. That is, the CPU 40A reads programs from the ROM 40B or storage 40D and executes the programs using the RAM 40C as a work area. The CPU 40A controls the above components and performs various arithmetic operations in accordance with the programs recorded in the ROM 40B or storage 40D.

[0019] The ROM 40B stores various programs and various data. The RAM 40C temporarily stores programs or data as a working area. The storage 40D is configured with an HDD (Hard Disk Drive) or an SSD (Solid State Drive) and stores various programs including an operating system and various data. In this embodiment, the ROM 40B or the storage 40D stores programs for performing display processing, various data, and the like.

[0020] The communication I / F 40E is an interface for the vehicle rear monitoring system 10 to communicate with a server and other devices (not shown), and uses standards such as Ethernet (registered trademark), LTE, FDDI, and Wi-Fi (registered trademark).

[0021] The input / output I / F 40F is connected to the first display unit 24, the second display unit 25, and a head-up display device (HUD) 44. An image is projected onto the third display unit 26 by the head-up display device 44.

[0022] The input / output I / F 40F is connected to a system bus 43 installed in the vehicle 12. The system bus 43 is connected to an imaging unit 46, a target detection unit 47, a rear view confirmation operation unit 48, an in-vehicle device 49, and the like.

[0023] The imaging unit 46 includes at least a rear camera 46A that images the area behind the vehicle 12, and also includes a front camera that images the area in front of the vehicle 12, a front side camera that images the areas in front of the vehicle 12, and a rear side camera that images the areas in rear of the vehicle 12. The imaging unit 46 is configured with a color CCD (Charge Coupled Device) camera or the like. The rear camera 46A is installed, for example, inside the passenger compartment 13 at the rear of the vehicle 12, in the center in the vehicle width direction.

[0024] Note that rear camera 46A is not limited to this as long as it can acquire rear images of vehicle 12, and may be installed at the front of vehicle 12 or outside passenger compartment 13. Rear camera 46A captures images of the area behind vehicle 12 at a predetermined frame rate based on an imaging signal from CPU 40A, and outputs rear image data to ECU 28. Images (including rear images) captured by imaging unit 46 are stored in storage 40D, for example.

[0025] The target detection unit 47 is a device that detects targets behind the vehicle 12, and specifically, is configured as a back sonar device installed at the rear end of the vehicle 12. The back sonar device includes an ultrasonic sensor that transmits ultrasonic waves toward the target and receives the reflected waves with a receiver to detect the presence or absence of a target and the distance to the target. Specifically, the distance from the ultrasonic sensor to the target is calculated by calculating the relationship between the time required for transmitting and receiving the ultrasonic waves and the speed of sound. In this embodiment, the target detection unit 47 also includes a signal processing unit (not shown) that processes the detection results of surrounding targets. The signal processing unit excludes roadside objects such as guardrails as noise or stationary targets based on changes in the relative position and relative speed of each target included in the most recent multiple detection results, and tracks and monitors the following vehicle 60 as a target. The target detection unit 47 outputs detected distance information, etc. to the ECU 28.

[0026] To enable rearward confirmation of the vehicle 12, the rear confirmation operation unit 48 outputs an instruction to display the rear image P acquired by the rear camera 46A on at least one of the first display unit 24, the second display unit 25, and the third display unit 26. Specifically, the rear confirmation operation unit 48 is, for example, configured by a switch (not shown) provided on the steering wheel 16, and outputs an instruction signal to the ECU 28 to display the rear image P on at least one of the first display unit 24, the second display unit 25, and the third display unit 26 when the driver operates this switch.

[0027] The present invention is not limited to the above switch, and the rearward check operation unit 48 may instruct the display of a rearward image by, for example, operating various setting items displayed in the display area 24A of the first display unit 24. In this embodiment, as an example, when a display instruction is output by the rearward check operation unit 48, a rearward image is projected from the head-up display device 44 onto the display area 26A of the third display unit 26. In other words, the third display unit 26 is used as a display unit.

[0028] The in-vehicle devices 49 are various devices mounted on the vehicle 12, such as an air conditioner, an audio system, a car navigation system, a voice input system, and various sensor devices such as a GPS (global positioning system) sensor.

[0029] (Functional configuration of ECU28) The ECU 28 uses the above hardware resources to realize various functions. The functional configuration realized by the ECU 28 will be described with reference to FIG.

[0030] 3, the ECU 28 includes, as functional components, a display instruction detection unit 52, a rear image acquisition unit 54, a distance determination unit 56, and a display magnification change unit 58. Each functional component is realized by the CPU 40A reading and executing a program stored in the ROM 40B or the storage 40D.

[0031] The display instruction detection unit 52 detects an instruction signal input to the ECU by the rear checking operation unit in order to display the rear image captured by the rear camera in the display area of ​​the third display unit .

[0032] The rear image acquisition unit 54 acquires a rear image P captured by the rear camera 46A. Specifically, the rear image acquisition unit 54 acquires rear image data stored in the storage 40D.

[0033] The distance determination unit 56 determines whether the distance between the following vehicle 60 as a target detected by the target detection unit 47 and the host vehicle 12 is equal to or less than a predetermined threshold. Specifically, it determines whether the distance value based on the distance information input to the ECU 28 by the target detection unit 47 is equal to or less than the predetermined threshold. The predetermined threshold is a value that is set in advance in the host vehicle 12.

[0034] When the distance determination unit 56 determines that the distance between the following vehicle 60 and the host vehicle 12 is equal to or less than a predetermined threshold, the display magnification change unit 58 reduces the display magnification of the rear image P in the display area 26A of the third display unit 26 to a value smaller than a preset display magnification. The preset display magnification may be a value that differs for each vehicle model, for example, and specifically refers to the display magnification of the rear image P displayed in the display area 26A during normal driving. When the rear image P is displayed at the preset display magnification, a preset area including the center of the rear image P captured by the rear camera 46A is displayed, rather than the entire area. That is, a display range displayed in the display area 26A in the rear image P is preset for each display magnification. Specifically, the larger the display magnification, the smaller the display range displayed in the display area 26A in the rear image P, and the smaller the display magnification, the larger the display range displayed in the display area 26A in the rear image P.

[0035] For example, as shown in Fig. 4, when the rear image P is displayed in the display area 26A at a preset display magnification, the following vehicle 60 is displayed in the entire display area 26A. Also, as shown in Fig. 5, when the display magnification change unit 58 sets the display magnification of the rear image in the display area 26A of the third display unit 26 to be smaller than the preset display magnification, the following vehicle 60 is displayed in the display area 26A in the rear image P at a smaller size than in Fig. 4. In other words, the following vehicle 60 is zoomed out and displayed in the display area 26A. When the display magnification is reduced, as shown in Fig. 5, a person 70 riding a motorcycle, a lane S between adjacent lanes, and the like, which were not displayed in Fig. 4, are also displayed.

[0036] (Display processing) Next, a series of processes executed in the vehicle rear monitoring system 10 will be described with reference to the flowchart shown in Fig. 6. The display process executed in the vehicle rear monitoring system 10 is mainly performed by the ECU 28, and is executed by the CPU 40A reading out a display control program from the ROM 40B or the storage 40D, expanding it into the RAM 40C, and executing it. In this embodiment, the following process is started after an instruction to turn on the display in the display area 26A of the third display unit 26 is given.

[0037] 6, the display instruction detection unit 52 of the ECU 28 determines whether the rear view confirmation operation unit 48 has turned on the display of the rear view image P acquired by the rear view camera 46A in the display area 26A of the third display unit 26 in step S11 (step S11). That is, the display instruction detection unit 52 detects whether the rear view confirmation operation unit 48 has input an instruction signal to the ECU 28.

[0038] In step S11, if the display of the rear image P is not turned on (step S11; NO), the process of step S11 is repeated until it is turned on. On the other hand, in step S11, if the display of the rear image P is turned on (step S; YES), the rear image acquisition unit 54 acquires the rear image P, and the CPU 40A displays the rear image P in the display area 26A of the third display unit 26 at a preset display magnification (step S12).

[0039] Next, in step S13, the target detection unit 47 detects whether or not a following vehicle 60 is present as a target, and if a following vehicle 60 is not detected (step S13; NO), the CPU 40A continues to display the rear image P in the display area 26A of the third display unit 26 at a preset display magnification (step S14).

[0040] On the other hand, if the following vehicle 60 is detected in step S13 (step S13; NO), the target detection unit 47 detects the distance between the host vehicle 12 and the following vehicle 60 (step S15).

[0041] Next, the distance determination unit 56 determines whether a certain time has elapsed while the distance detected in step S15 is equal to or less than a predetermined threshold (step S16). If the certain time has not elapsed while the distance is equal to or less than the predetermined threshold (step S16; NO), the CPU 40A continues to display the rear image P in the display area 26A of the third display unit 26 at a preset display magnification (step S14).

[0042] If a certain period of time has elapsed while the distance is below a predetermined threshold (step S16; YES), the display magnification change unit 58 displays the rear image P in the display area 26A of the third display unit 26 at a display magnification smaller than the preset display magnification (step S17).

[0043] After the process of step S14 or step S17 is performed, the CPU 40A next determines whether the rear image display has been turned off (step S18). If there is no instruction to turn it off (step S18; NO), the CPU 40A proceeds to step S12 and repeats the processes from step S12 onwards. On the other hand, if there is an instruction to turn it off in step S18 (step S18; YES), the CPU 40A turns off the display area 26A of the third display unit 26 and the head-up display device 44 in step S19, and ends the series of processes.

[0044] In this way, the CPU 40A changes the display magnification in accordance with the distance between the following vehicle 60 and the host vehicle 12 and displays the rear image P in the display area 26A until the display of the rear image P is turned off.

[0045] (Action and effect) Next, the effects of this embodiment will be described.

[0046] In the vehicle rear monitoring system 10 according to this embodiment, when the distance between the host vehicle 12 and a following vehicle 60 as a target detected by the target detection unit 47 becomes equal to or less than a predetermined threshold, the ECU 28 reduces the display magnification of the captured image, that is, the rear image P, in the display area 26A of the third display unit 26 to a value smaller than a preset display magnification. Therefore, when the following vehicle 60 approaches, the image of the following vehicle 60 displayed in the display area 26A of the third display unit 26 is zoomed out, thereby reducing the sense of oppression felt by the driver.

[0047] In the above embodiment, as shown in FIG. 5, the rear image P is displayed at a display magnification smaller than a preset display magnification, but the present invention is not limited to this. For example, as shown in FIG. 7, marks 80 such as angle brackets may be displayed at the four corners of the display range (see FIG. 4) displayed at the preset display magnification in the rear image P. This prevents the driver from misjudging the distance to the following vehicle 60 when the following vehicle 60 is displayed in a zoomed-out manner in the rear image P. Note that the marks 80 are not limited to angle brackets, but may be a circle, a cross, or a desired icon. Furthermore, the mark 80 is not limited to the above, and may instead display a message such as "zooming out."

[0048] Furthermore, in the above embodiment, a back sonar device is used as the target detection unit 47, but the present invention is not limited to this. For example, a sensor such as a radar or a LIDAR (Light Detection and Ranging or Laser Imaging Detection and Ranging) may be used. The radar detects the distance and direction of targets around the vehicle 12 using radio waves. The LIDAR detects the distance and direction of targets around the vehicle 12 using laser light.

[0049] Furthermore, in the above embodiment, the target detection unit 47 detects the following vehicle 60 as a target, and therefore the rear camera 46A can be used as the target detection unit 47. In this case, the following vehicle 60 is detected from the rear image P acquired by the rear camera 46A, and when the size of the following vehicle 60 is equal to or larger than a predetermined size, it is determined that the distance between the following vehicle 60 and the host vehicle 12 is equal to or smaller than a predetermined threshold. Note that, if the target detection unit 47 is configured with two rear cameras 46A spaced apart in the vehicle width direction, the distance between the following vehicle 60 and the host vehicle 12 may be calculated based on parallax images captured by the two rear cameras 46A, i.e., stereo cameras. In this case, a known method can be used to calculate the distance. Note that, in the present invention, any technology may be used as long as it can detect the distance between the following vehicle 60 and the host vehicle 12.

[0050] In addition, in this embodiment, the camera constituting the rear camera 46A is configured as a color CCD, but the present invention is not limited to this. For example, it may be configured as a monochrome CCD or as another type of camera such as a CMOS (Complementary Metal Oxide Semiconductor) camera.

[0051] Furthermore, in the above embodiment, when a display instruction is output by the rear check operation unit 48, a rearward image is projected from the head-up display device 44 onto the display area 26A of the third display unit 26, but the present invention is not limited to this. For example, the rearward image may be displayed in the display area 24A of the first display unit 24, or in the display area 25A of the second display unit 25, and the display area is not particularly limited. In other words, the first display unit 24 or the second display unit 25 may be the display unit.

[0052] In the above embodiment, the rear image P captured by the rear camera 46A is the captured image captured by the imaging unit 46, but the present invention is not limited to this. For example, the captured image may be a rear side image captured by a rear side camera that captures the side behind the vehicle 12. In other words, a camera that can capture an image of the following vehicle 60 may be used as the imaging unit.

[0053] In addition, various processors other than a CPU may execute the processes executed by the CPU 40A shown in FIG. 2 after reading software (programs) in the above embodiment. Examples of processors in this case include programmable logic devices (PLDs) such as field-programmable gate arrays (FPGAs), whose circuit configuration can be changed after fabrication, and dedicated electrical circuits such as application-specific integrated circuits (ASICs), which are processors with circuit configurations specifically designed to execute specific processes. Each process may be executed by one of these various processors, or by a combination of two or more processors of the same or different types (e.g., multiple FPGAs, or a combination of a CPU and an FPGA). The hardware structure of these various processors is, more specifically, an electrical circuit that combines circuit elements such as semiconductor devices.

[0054] Furthermore, each of the programs described in the above embodiments may be provided in a form recorded on a recording medium such as a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (Digital Versatile Disc Read Only Memory), a USB (Universal Serial Bus) memory, etc. Furthermore, the programs may be downloaded from an external device via a network.

[0055] The above describes one embodiment of the present invention, but the present invention is not limited to the above, and it goes without saying that it can be implemented in various other modified forms within the scope of the gist of the present invention. [Explanation of symbols]

[0056] 10. Vehicle rear monitoring system 12 vehicles 13 Cabin 24 1st display section (display section) 25 2nd display section (display section) 26 Third display section (display section) 28 ECU (display control unit) 46 Imaging unit 47 Target detection unit 60 following vehicles P Rear image (captured image)

Claims

1. an imaging unit that images at least one of a rearward and a rearward side of the vehicle; a display unit provided in a passenger compartment of the vehicle and configured to display an image captured by the imaging unit; a display control unit that, when a distance between the host vehicle and a target detected by a target detection unit that detects a target behind the host vehicle is greater than a predetermined threshold, causes the display unit to display a predetermined area including a center portion of the captured image at a predetermined display magnification, and, when the distance becomes equal to or less than the predetermined threshold, causes the display magnification of the captured image on the display unit to be smaller than the predetermined display magnification, and increases the area of ​​the captured image to be displayed on the display unit as the display magnification decreases; Vehicle rearview monitoring system including:

2. A vehicle rear monitoring system as described in claim 1, wherein the display control unit displays marks at the four corners of a predetermined area including the center of the captured image when the captured image is displayed at a display magnification smaller than the predetermined display magnification.

Images