Cleaning System for In-Vehicle Sensors

Abstract

To provide an on-vehicle sensor cleaning system which curbs wasteful consumption of cleaning liquid and / or battery power.SOLUTION: An on-vehicle sensor cleaning system 1 comprises: an imaging device 20 which takes an image of an object existing around a vehicle V and outputs information on the image; a radar device 30 which emits laser light outside the vehicle V and acquires and outputs information on the object existing around the vehicle V on the basis of the reflected laser light; a cleaning device 50 which cleans the imaging device by injecting cleaning liquid W or air toward the imaging device 20; and a control device 10 which controls the cleaning device 50. When determining that the imaging device 20 has adhesion of dirt on the basis of the information acquired through the imaging device 20 and that no suspended solids exist in a space around the vehicle V on the basis of the information acquired through the radar device 30, the control device 10 causes the cleaning device 50 to clean the imaging device 20.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a cleaning system for in-vehicle sensors.

Background Art

[0002] Conventionally, a vehicle equipped with an imaging device for acquiring optical information outside the vehicle is known. This vehicle has functions such as detecting surrounding obstacles and detecting the inter-vehicle distance based on the acquired optical information (hereinafter referred to as the "environmental recognition function").

[0003] A lens (optical filter) is provided at a site that guides outside light to the light receiving part of the imaging device mounted on the vehicle. If dirt (such as mud, dust, raindrops, etc.) adheres to the surface of this lens, the quality of the acquired optical information becomes lower than when there is no dirt on the lens, and the accuracy of environmental recognition based on that optical information decreases. Therefore, a cleaning system for removing the dirt adhering to the surface of the lens has been proposed (see, for example, Patent Document 1). This cleaning system includes a control device that determines whether or not dirt adheres to the lens based on optical information. When the control device determines that "dirt adheres to the lens", it operates an electric pump to spray a cleaning liquid (or air) toward the lens. Thereby, the dirt on the lens is removed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] In the above-described conventional system, there is a risk that the control device may misrecognize dust that has been lifted during driving or an object floating in front of the lens such as rain or snow (hereinafter referred to as "space floating dirt") as dirt adhering to the lens. In this case, although there is actually no dirt adhering to the lens, the lens is cleaned. That is, the electric pump is operated and the cleaning liquid (or air) is jetted toward the lens. In this case, the power of the battery is wasted to operate the electric pump. Also, the cleaning liquid is wasted.

[0006] One object of the present invention is to provide a cleaning system for an in-vehicle sensor that suppresses the wasteful consumption of the cleaning liquid and / or the power of the battery.

[0007] To solve the above problems, a cleaning system (1) for an in-vehicle sensor according to the present invention is mounted on a vehicle (V). An imaging device (20) that images a target existing around the vehicle and outputs information regarding the image; A radar device (30) that emits laser light to the outside of the vehicle and acquires and outputs information regarding a target existing around the vehicle based on the reflected light; A cleaning device (50) that jets a cleaning liquid or air toward the imaging device to clean the imaging device; A control device (10) that controls the cleaning device; and includes. When the control device determines that dirt is adhering to the surface of the imaging device based on the information acquired from the imaging device and determines that there are no floating objects in the space around the vehicle based on the information acquired from the radar device, the control device causes the cleaning device to clean the imaging device. The imaging device is a component of an electronic mirror device that displays an image of the surroundings of the vehicle. When the control device determines that dirt is attached to the imaging device based on the information acquired from the imaging device and determines that there are floating objects in the space around the vehicle based on the information acquired from the radar device, it proposes to recommend to the driver to use an optical mirror instead of the electronic mirror device.

[0009] In the in-vehicle sensor cleaning system configured as described above, even if the information output from the imaging device or the information obtained by analyzing the same (hereinafter referred to as "information X") indicates that "dirt is attached to the imaging device (lens, optical filter, etc.)", in reality, it may not be the case that dirt is attached, but rather that floating dirt in the space is generated. In this case, if the imaging device is cleaned, the cleaning liquid and / or the power of the battery will be wasted. Therefore, in the in-vehicle sensor cleaning system according to the present invention, when information X indicates that "dirt is attached to the imaging device" and the information obtained from the radar device (hereinafter referred to as "information Y") indicates that "there is no floating object in the space (rear) around the vehicle V (no floating dirt in the space)", the imaging device is cleaned. That is, in the present invention, the imaging device is cleaned only in a situation where there is a high possibility that dirt is attached to the imaging device. Therefore, it is possible to suppress the wasteful consumption of the cleaning liquid and / or the power of the battery.

[0011] In a situation where information X indicates that "dirt is attached to the imaging device" and information Y indicates that "floating dirt in the space is generated", even if the imaging device is cleaned, the sharpness of the image of the display device of the electronic mirror is unlikely to be improved. Therefore, the in-vehicle sensor cleaning system of the present aspect proposes to the driver to "recommend using the optical mirror" without cleaning the imaging device in this situation. Thereby, while suppressing the wasteful consumption of the cleaning liquid and / or the power of the battery, the driver's attention can be aroused.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0013] (Configuration) The vehicle-mounted sensor cleaning system 1 according to an embodiment of the present invention shown in FIG. 1 is applied to a vehicle V. The vehicle-mounted sensor cleaning system 1 includes a sensor ECU 10, an imaging device 20, a radar device 30, a display device 40, and a cleaning device 50.

[0014] The sensor ECU 10 includes a microcomputer including a CPU 10a, a ROM 10b, a RAM 10c, a timer 10d, and the like. In this specification, "ECU" means an electronic control unit, and includes a microcomputer including a CPU, a RAM, a ROM, and the like. The CPU realizes various functions by executing instructions stored in the ROM.

[0015] The sensor ECU 10 is connected to other ECUs (not shown) via a CAN (Controller Area Network) so as to be capable of transmitting and receiving information to and from each other.

[0016] The imaging device 20 captures a target and acquires image data. A digital camera can be adopted as the imaging device 20. That is, the imaging device 20 includes a lens 21, a CCD (charge coupled device) 22, an image recognition unit 23, and the like. As shown in FIG. 2, an opening O1 is provided at the central portion in the vehicle width direction of the rear panel P of the vehicle V, which is located directly below the rear windshield glass G, and the lens 21 is exposed to the outside of the vehicle through this opening O1. The image recognition unit 23 acquires the image data obtained by capturing the rear of the vehicle V at a predetermined frame rate from the CCD 22. Then, based on the acquired image data, the image recognition unit 23 recognizes the type (for example, white line, guardrail, etc.), position, etc. of the target located in front of the imaging device 20 (behind the vehicle V), and transmits the information representing the recognition result to the sensor ECU 10. In addition, the image recognition unit 23 analyzes the image data to determine whether dirt (mud, dust, raindrops, etc.) is attached to the outer surface of the lens 21, and transmits the information X representing the determination result to the sensor ECU 10. As the determination method, for example, the method described in Japanese Patent Application Laid-Open No. 2015-269875 can be adopted. However, as described above, even if the determination result indicates that "dirt is attached to the lens 21", actually, floating dirt in the space may have occurred and the lens 21 may not have dirt attached to it.

[0017] The radar device 30 uses laser light (infrared light) to detect the shape of an object located behind the vehicle V, the distance to the object, etc. As the radar device 30, LiDAR can be adopted. That is, the radar device 30 includes a light emitting unit 31, a light receiving unit 32, and an information processing unit 33 (see FIG. 1). An opening O2 is provided at the central portion in the vehicle width direction of the rear bumper cover of the vehicle, and a window member as an "emission port of laser light and an incident port of its reflected light" is fitted into this opening O2. The light emitting unit 31 emits (emits) laser light to the peripheral area (rear) of the vehicle. The light receiving unit 32 receives the laser light (i.e., the reflected light) reflected by a three-dimensional object existing within the radiation range of the laser light. The information processing unit 33 is based on the reflected light information including the phase difference between the laser light emitted from the light emitting unit 31 and the reflected light received by the light receiving unit 32, the attenuation level of the reflected light, and the time from emitting the laser light to receiving the reflected light, etc. It calculates the distance between the vehicle V and the three-dimensional object, the relative speed between the vehicle V and the three-dimensional object, the relative position (direction) of the three-dimensional object with respect to the vehicle V, etc., and transmits the information representing the calculation result to the sensor ECU 10. Further, the information processing unit 33 determines the presence or absence of airborne substances such as mud, dust, and raindrops (whether airborne dirt has occurred) based on the reflected light information, and acquires the information Y representing the determination result and transmits it to the sensor ECU 10. As a specific method for acquiring the above information, for example, the method described in Japanese Patent No. 6862840 can be adopted.

[0018] The display device 40 acquires image data from the CCD 22 and displays an image based on the image data. As the display device 40, a liquid crystal display device can be adopted. The imaging device 20 and the display device 40 constitute a well-known electronic mirror device (digital rearview mirror). The display device 40 has a switching function to a normal optical mirror (function as a reflector).

[0019] The cleaning device 50 sprays the cleaning liquid W toward the lens 21 to remove the dirt (such as mud, dust, and raindrops) adhering to the outer surface of the lens 21. As shown in FIG. 3, the cleaning device 50 includes a tank 51 and an injection device 52.

[0020] The tank 51 is a container for storing the cleaning liquid W.

[0021] The injection device 52 includes an electric pump 521, a pipe 522, and a nozzle 523. The electric pump 521 includes an impeller, an electric motor for rotating the impeller, and the like. The pipe 522 is composed of a suction pipe 522a and a discharge pipe 522b. The suction port 521a of the electric pump 521 is connected to the discharge port 51a of the tank 51 through the suction pipe 522a. On the other hand, the discharge port 521b of the electric pump 521 is connected to the nozzle 523 through the discharge pipe 522b.

[0022] As shown in FIG. 2, the tip (discharge port) of the nozzle 523 is exposed to the outside of the vehicle through an opening O3 provided near the opening O1 in the rear panel P and is directed toward the lens 21.

[0023] (Operation) The sensor ECU 10 controls the cleaning device 50 (the on / off state of the power supply to the electric pump 521) based on the information acquired from the imaging device 20 and the radar device 30.

[0024] Specifically, in the following situation A, the sensor ECU 10 sets the power supply device (relay R) that supplies power from the battery of the vehicle V to the electric pump 521 to the on state and operates the electric pump 521. As a result, the cleaning liquid W is sprayed from the nozzle 523 toward the lens 21, and the lens 21 is cleaned. (Situation A) The information X acquired from the imaging device 20 indicates that "dirt is attached to the lens 21", and the information Y acquired from the radar device 30 indicates that "there is no floating matter (no floating dirt is generated) in the space around (rear) the vehicle V".

[0025] When a predetermined time has elapsed since the cleaning of the lens 21 was started, the sensor ECU 10 sets the power supply device to the off state and stops the cleaning of the lens 21. Note that the sensor ECU 10 causes the display device on the instrument panel to display information indicating that the lens 21 is being cleaned (for example, a predetermined LED is lit).

[0026] Further, in the following situation B, the sensor ECU 10 presents information indicating that "it is recommended to use a normal optical mirror (rearview mirror) mounted on the vehicle V instead of the electronic mirror device". For example, the sensor ECU 10 causes the display device on the instrument panel to display predetermined information. (Situation B) The information X acquired from the imaging device 20 indicates that "the lens 21 is dirty", and the information Y acquired from the radar device 30 indicates that "there are floating objects in the space around (behind) the vehicle V (space floating dirt has occurred)".

[0027] Next, a computer program (cleaning program P1) executed by the CPU 10a of the sensor ECU 10 (hereinafter simply referred to as "CPU") to realize the above operations (cleaning of the lens 21 and presentation recommending switching to the optical mirror) will be described. The CPU repeatedly executes the cleaning program P1 at a predetermined cycle.

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

[0029] When the CPU proceeds to step 101, it determines whether the information X acquired from the imaging device 20 indicates that "the lens 21 is dirty". If the information X indicates that "the lens 21 is dirty" (101: Yes), the CPU proceeds to step 102. On the other hand, if the information X indicates that "the lens 21 is not dirty" (101: No), the CPU proceeds to step 105 and ends the execution of the cleaning program P1.

[0030] When the CPU proceeds to step 102, it determines whether the information Y acquired from the radar device 30 indicates that "floating dirt in the space has occurred". If the information Y indicates that "floating dirt in the space has occurred" (102: Yes), the CPU proceeds to step 103. On the other hand, if the information Y indicates that "no floating dirt in the space has occurred" (102: No), the CPU proceeds to step 104 described later.

[0031] When the CPU proceeds to step 103, it presents information indicating that "it is recommended to use a normal optical mirror (reflector) mounted on the vehicle V instead of the electronic mirror device". Then, the CPU proceeds to step 105.

[0032] When the CPU proceeds from step 102 to step 104, it supplies power to the cleaning device 50 to cause the cleaning device 50 to clean the lens 21. That is, the CPU injects the cleaning liquid W toward the lens 21 for a predetermined time. During that time, information indicating that "the lens 21 is being cleaned" is displayed on the display device of the instrument panel (for example, a predetermined LED is lit). Then, the CPU proceeds to step 105.

[0033] (Effect) As described above, even if information X indicates that "dirt is attached to the lens 21", in reality, dirt may not be attached to the lens 21, but floating dirt in the space may occur. That is, the determination result of the image recognition unit 23 of the imaging device 20 may be incorrect. In this case, if the lens 21 is cleaned, the cleaning liquid W and the power of the battery are wasted. Also, during that time, an image of the rear of the vehicle V is not displayed on the display device 40. That is, during that time, it becomes difficult for the driver to confirm the safety of the rear. Therefore, the in-vehicle sensor cleaning system 1 according to the present embodiment cleans the lens 21 in a situation A where information X indicates that "dirt is attached to the lens 21" and information Y indicates that "there are no floating objects (no floating dirt in the space) in the space around (rear) the vehicle V". That is, in the present embodiment, the lens 21 is cleaned only in the situation A where there is a high possibility that dirt is attached to the lens 21. Therefore, it is possible to suppress the wasteful consumption of the cleaning liquid W and the power of the battery. Also, the frequency at which it becomes difficult to confirm the safety of the rear can be reduced.

[0034] Also, in a situation B where information X indicates that "dirt is attached to the lens 21" and information Y indicates that "there are floating objects (floating dirt in the space) in the space around (rear) the vehicle V", even if the lens 21 is cleaned, the sharpness of the image on the display device 40 is unlikely to be improved. Therefore, in the situation B, the in-vehicle sensor cleaning system 1 proposes to the driver to "recommend using the optical mirror" without cleaning the lens 21. Thereby, while suppressing the wasteful consumption of the cleaning liquid W and the power of the battery, the driver's attention can be aroused.

[0035] The present invention is not limited to the above-described embodiment, and as described below, various modifications can be adopted within the scope of the present invention.

[0036] In the above-described embodiment, the cleaning liquid W is sprayed onto the lens 21. Instead of this, air may be blown onto the lens 21. Further, in addition to the lens 21, the window member of the radar device 30 may be cleaned. Also, in the above-described embodiment, the imaging device 20 includes the image recognition unit 23. Instead of this, the CPU 10a of the sensor ECU 10 may acquire image data from the CCD 22 and execute various calculations using the image data. Further, in the above-described embodiment, the radar device 30 includes the information processing unit 33. Instead of this, the CPU 10a of the sensor ECU 10 may acquire received light data from the light receiving unit 32 and execute various calculations using the received light data.

Explanation of Reference Numerals

[0037] 1…In-vehicle sensor cleaning system, 10…Sensor ECU, 20…Imaging device, 21…Lens, 22…CCD, 23…Image recognition unit, 30…Radar device, 31…Light emitting unit, 32…Light receiving unit, 33…Information processing unit, 40…Display device, 50…Cleaning device, V…Vehicle, W…Cleaning liquid

Claims

【Claim 1】 A cleaning system for in-vehicle sensors mounted on a vehicle, comprising: an imaging device that images an object existing around the vehicle and outputs information regarding the image; a radar device that emits laser light outward from the vehicle and acquires and outputs information regarding an object existing around the vehicle based on the reflected light; a cleaning device that sprays cleaning liquid or air toward the imaging device to clean the imaging device; a control device that controls the cleaning device; wherein the imaging device is a component of an electronic mirror device that displays an image around the vehicle; the control device is configured to cause the cleaning device to clean the imaging device when it is determined that dirt has adhered to the surface of the imaging device based on the information acquired from the imaging device and it is determined that there are no floating substances in the space around the vehicle based on the information acquired from the radar device, and is configured to propose to the driver to recommend using an optical mirror instead of the electronic mirror device when it is determined that dirt has adhered to the imaging device based on the information acquired from the imaging device and it is determined that there are floating substances in the space around the vehicle based on the information acquired from the radar device.

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