Wiper control device and wiper control method

Abstract

A wiper control device 10: determines, on the basis of window information, whether water droplets are on a window glass; identifies the amount of water droplets from the window information; calculates, on the basis of line-of-sight information, the number of times a driver looks at a room mirror; sets a threshold value for the number of times in accordance with the amount of water droplets; and, if it is determined that water droplets are on the window glass and the calculated number of times the driver looks at the room mirror is equal to or greater than the threshold value for the number of times, outputs a control command to drive a rear wiper.

Description

[Technical Field]

[0001] The present invention relates to a wiper control device and a wiper control method. [Background technology]

[0002] Vehicle wiper devices that automatically operate the rear wiper are known (see, for example, Patent Document 1). The vehicle wiper device described in Patent Document 1 includes a water droplet detection device that detects water droplets on the back window glass, a driver monitor camera that monitors the driver, a control device, and a rear wiper drive device that drives the rear wiper. The control device determines whether there are water droplets on the back window glass and whether the driver's line of sight has shifted to the inner mirror, and when it determines that there are water droplets on the back window glass and that the driver's line of sight has shifted to the inner mirror, it outputs a signal to the rear wiper drive device to drive the rear wiper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-062791 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the vehicle wiper device described in Patent Document 1 is not suitable for the case where the amount of water droplets adhering to the back window glass is small. too, When the driver looks at the inner mirror, the rear wiper operates, which causes a problem in that the rear wiper operates against the driver's intention.

[0005] An object of the present invention is to provide a wiper control device and a wiper control method that can drive a rear wiper in accordance with the driver's intention. [Means for solving the problem]

[0006] The present invention determines whether or not there are water droplets on the window glass based on window information. 、 Calculates the number of times the driver looks at the rearview mirror based on gaze information. 、 It is determined that there are water droplets on the window glass. In this case, based on the calculated number of times and the line of sight information, The above problem is solved by outputting a control command to drive the rear wiper. [Effects of the Invention]

[0007] According to the present invention, the rear wiper can be driven in accordance with the driver's intention. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a block diagram of a wiper control system including a wiper control device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram for explaining a method for predicting the destination of the driver's line of sight. [Figure 3] FIG. 3 is a flowchart illustrating an example of a control procedure for executing a wiper control method according to an embodiment of the present invention. [Figure 4] FIG. 10 is a flowchart illustrating an example of a control procedure for executing a wiper control method according to a modified example of an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram of a wiper control system including a wiper control device 10 according to this embodiment. As shown in FIG. 1, the wiper control system is installed in a vehicle 1 and includes a windshield water droplet detection device 2, a front wiper drive device 3, a rear windshield water droplet detection device 4, an interior camera 5, a rear wiper drive device 6, and the wiper control device 10. Each component included in the wiper control system exchanges information with each other via an in-vehicle network such as a CAN. The wiper control device 10 detects water droplets on the windshield, detects the driver's gaze from the driver's line of sight in the vehicle interior, determines that water droplets are present on the windshield, and automatically drives the rear wiper if the driver looks at the rearview mirror multiple times or more.

[0010] The windshield water droplet detection device 2 is a water droplet sensor installed on the windshield (front window glass). The front wiper drive device 3 is equipped with an actuator for driving the front wipers. S water The drop detection device 4 is Rear glass (rear window glass) The interior camera 5 is a water droplet (raindrop) sensor installed in the interior of the vehicle. The interior camera 5 is a camera used to detect the driver's line of sight and captures an image of the driver's eyes. The interior camera 5 may be an infrared (IR) camera, a camera that captures RGB color images, an RGB-IR camera, or the like. The imaging element included in the camera may be a CMOS or CCD, or the like. The interior camera 5 may capture images of the windshield, rear windshield, and / or side windows in order to be used to detect water droplets. The rear wiper drive device 6 is equipped with an actuator for driving the rear wiper. The rear wiper drive device 6 drives the rear wiper based on a control command sent from the wiper control device 10.

[0011] The wiper control device 10 has a controller 11 that controls the rear wiper. The controller 11 is equipped with a computer having hardware and software, and this computer includes a ROM that stores programs, a CPU that executes the programs stored in the ROM, and a RAM that functions as an accessible storage device.

[0012] 1, the controller 11 is configured to include, as functional blocks, an information acquisition unit 12, a water droplet determination unit 13, a line of sight determination unit 14, and a wiper control unit 15, and executes each function through cooperation between software for executing each process and hardware. Note that in this embodiment, the functions of the controller 11 are divided into four blocks, and the functions of each functional block are explained, but the functions of the controller 11 do not necessarily have to be divided into four blocks.

[0013] The information acquisition unit 12 acquires window information related to the window glass of the vehicle 1 and driver's line of sight information. The information acquisition unit 12 acquires window information from at least one of the windshield water droplet detection device 2, the front wiper drive device 3, the rear window water droplet detection device 4, and the interior camera 5. The window information is information related to water droplets adhering to the window glass. The window information is information for identifying whether water droplets are present on the exterior surface of the windshield and / or rear window, and the amount of water droplets adhering to the exterior surface of the vehicle. The window information includes at least one of front wiper drive information indicating the drive status of the front wipers, detection information from the windshield water droplet detection device 2 (raindrop sensor) that detects water droplets on the front window, detection information from the rear window water droplet detection device 4 (raindrop sensor) that detects water droplets on the rear window, and an image of the window glass captured by the interior camera 5.

[0014] The information acquisition unit 12 acquires front wiper drive information from the front wiper drive device 3. The front wiper drive information indicates whether the front wipers are on or off and the drive speed of the front wipers. The drive speed corresponds to the time it takes for the wipers to make one full sweep. The detection information from the windshield water droplet detection device 2 indicates the amount of water droplets. The captured image of the windshield is used to identify water droplets through image processing. The information acquisition unit 12 performs image processing on the captured image of the driver to acquire driver gaze information. The driver gaze information indicates the driver's line of sight, point of gaze, etc. The driver gaze information is used to determine whether the driver looks at the rearview mirror and to calculate the number of times the driver looks at the rearview mirror. The rearview mirror is installed in a central position above the windshield. The rearview mirror is not limited to a mirror with a reflective function, but may also be an electronic rearview mirror equipped with a monitor (such as an LCD display or an OLED display) that displays images captured by a rearview camera.

[0015] The water droplet determination unit 13 determines whether water droplets are present on the window glass based on the window information. The water droplet determination unit 13 also identifies the amount of water droplets from the window information. If the front wiper drive information indicates that the front wipers are on, the water droplet determination unit 13 determines that water droplets are present. The water droplet determination unit 13 may also determine the amount of water droplets so that the greater the drive speed indicated by the front wiper drive information, or the faster the drive speed, the greater the amount of water droplets. When using detection information from the windshield water droplet detection device 2 and / or the rear window water droplet detection device 4, the water droplet determination unit 13 may determine the presence or absence of water droplets and the amount of water droplets indicated by the detection information. The water droplet determination unit 13 performs image processing on the captured image of the window glass to determine the presence or absence of water droplets and identify the amount of water droplets. The image processing may be performed using known image processing such as binarization or background subtraction. The water droplet determination unit 13 determines whether water droplets are present on the window glass based on whether water droplets are visible on the surface of the glass from the captured image of the window glass. The water droplet determination unit 13 also determines the amount of water droplets reflected on the surface of the windshield, rear windshield, and side windows. windowIt is only necessary to determine whether or not water droplets are present on the window glass and to identify the amount of water droplets for at least one of the glass panes.

[0016] The line of sight determination unit 14 determines whether the driver looks at the rearview mirror based on the line of sight information. The line of sight determination unit 14 also calculates the number of times the driver looks at the rearview mirror based on the line of sight information. The line of sight determination unit 14 determines whether the driver's line of sight is directed toward the position of the rearview mirror based on the line of sight information. For example, the line of sight determination unit 14 may identify the driver's line of sight from the line of sight information and determine whether the rearview mirror is located on an extension line from the driver's eye position along the line of sight. Then, if the line of sight determination unit 14 determines that the driver's line of sight is directed toward the position of the rearview mirror, it determines that the driver looks at the rearview mirror. Thus, the line of sight determination unit 14 determines whether the driver actually looks at the rearview mirror based on the line of sight information.

[0017] The line of sight determination unit 14 may determine whether the driver looks at the rearview mirror based on the direction of movement of the driver's line of sight. That is, when determining whether the driver looks at the rearview mirror, the line of sight determination unit 14 may determine that the driver looks at the rearview mirror if it is possible to predict that the driver will look at the rearview mirror, rather than being limited to whether the driver actually looks at the rearview mirror. In other words, the line of sight determination unit 14 may predict the destination of the driver's line of sight from the direction of movement of the driver's line of sight, and if the rearview mirror is at the destination, may determine that the driver looks at the rearview mirror before actually looking at the rearview mirror.

[0018] The gaze determination unit 14 may predict the gaze destination in the following manner. FIG. 2 is a schematic diagram illustrating a method for predicting the gaze destination. FIG. 2(a) is a schematic diagram illustrating the positional relationship between the driver and the windshield as viewed from the side of the vehicle. The dotted line corresponds to the cross section of the windshield. FIG. 2(b) is a diagram illustrating the driver's gaze when looking at the windshield from inside the vehicle, which corresponds to the driver's field of view when looking forward from the driver's seat. The gaze determination unit 14 predicts the gaze destination using gaze tracking. The gaze determination unit 14 identifies a gaze reference line on the windshield that connects the installation position of the rearview mirror and a predetermined reference position. The predetermined reference position is a predetermined position on the windshield that is in the driver's line of sight and is set in advance. For example, when the vehicle is traveling straight and the driver is looking ahead of the vehicle 1, the reference position is the position on the windshield that is in the driver's line of sight when the driver's face is facing forward. Point a in FIG. 2 corresponds to the reference position (the "first position" of the present invention). The installation position of the rearview mirror on the windshield is the position on the windshield that is in front of the driver's line of sight when looking at the rearview mirror. Point b in Figure 2 corresponds to the installation position of the rearview mirror (the "second position" of the present invention). The line of sight reference line represents the direction of movement of the driver's line of sight when the driver moves his / her line of sight from a state where he / she is looking ahead of the vehicle 1 to the rearview mirror. d represents the gaze reference line.

[0019] The line-of-sight determination unit 14 determines the direction of movement of the driver's line of sight based on the line-of-sight information, and if the determined direction of movement is along the line of sight reference line, determines that the driver is looking at the rearview mirror. In the example of FIG. 2, when a position on the windshield in front of the driver's line of sight moves from point a to point b, the direction of movement is along the line of sight reference line. The line-of-sight determination unit 14 determines the position on the windshield in front of the driver's current line of sight (hereinafter simply referred to as the viewpoint) based on the line-of-sight information. The viewpoint is expressed by position coordinates. The line-of-sight determination unit 14 calculates the amount of movement between the position coordinates of the viewpoint determined previously and the position coordinates determined this time. If the amount of movement is equal to or greater than a predetermined value, the line-of-sight determination unit 14 determines the direction of movement of the position coordinates indicating the viewpoint. If the direction of movement is along the line of sight reference line, the line-of-sight determination unit 14 determines that the driver is looking at the rearview mirror. The line of sight determination unit 14 can determine whether the driver looks at the rearview mirror when the driver's viewpoint starts to move, before the driver's viewpoint actually moves from point a to point b shown in Figure 2.

[0020] Various pieces of information regarding the line of sight reference line, the reference position, and the installation position of the rearview mirror may be stored in advance in a memory or the like. The predetermined reference position may also be the position of the side mirror, the position of the shift lever, the position of the hazard switch, or the like. For example, when changing lanes, the driver checks the rearward view in the side mirror before moving into an adjacent lane, and then checks the rearward view in the rearview mirror. Since the driver's line of sight moves from the side mirror to the rearview mirror at this time, the position of the side mirror may be preset as the reference position. For example, when backing a vehicle into parking, the driver first operates the shift lever to move the gear to the reverse position, and then looks at the rearview mirror. Since the driver's line of sight moves from the shift lever to the rearview mirror at this time, the position of the shift lever may be preset as the reference position. Similarly, when backing a vehicle into parking, the driver may look at the rearview mirror after turning on the hazard switch, so the position of the hazard switch may be preset as the reference position.

[0021] The line-of-sight determination unit 14 calculates the number of times the driver looks at the rearview mirror (hereinafter simply referred to as the "number of looks"). After determining that the driver looks at the rearview mirror, the line-of-sight determination unit 14 determines whether the driver's line of sight has moved from the position of the rearview mirror. Then, after determining that the driver's line of sight has moved from the position of the rearview mirror, the line-of-sight determination unit 14 determines whether the driver looks at the rearview mirror based on the direction of movement of the driver's line of sight in the same manner as described above. The line-of-sight determination unit 14 repeats this series of determination processes and increments the number of looks when it determines that the driver looks at the rearview mirror. Note that the line-of-sight determination unit 14 may reset the number of looks if it does not determine that the driver looks at the rearview mirror for a certain period of time after incrementing the number of looks, that is, if there is no change in the number of looks. In this way, the line-of-sight determination unit 14 calculates the number of looks per predetermined period of time.

[0022] The wiper control unit 15 controls the rear wiper based on the determination results of the water droplet determination unit 13 and the line of sight determination unit 14. When it is determined that there are water droplets on the window glass and the number of times of looking calculated by the line of sight determination unit 14 is equal to or greater than a predetermined number threshold, the wiper control unit 15 outputs a control command to drive the rear wiper to the rear wiper drive device 6. On the other hand, when it is determined that there are no water droplets on the window glass or the number of times of looking calculated by the line of sight determination unit 14 is less than the predetermined number threshold, the wiper control unit 15 does not output a control command to drive the rear wiper to the rear wiper drive device 6, and does not drive the rear wiper. The number threshold is a natural number (an integer greater than or equal to 1) and is a value set by the wiper control unit 15 according to the amount of water droplets.

[0023] The wiper control unit 15 sets the number threshold in accordance with the amount of water droplets. The wiper control unit 15 sets the number threshold so that the larger the amount of water droplets, the smaller the number threshold. Alternatively, the wiper control unit 15 sets the number threshold so that the amount of water droplets becomes smaller when the amount of water droplets is equal to or less than a predetermined water droplet amount threshold. beWhen the amount of water droplets is large, the number of times threshold is set to a high value, and when the amount of water droplets is greater than the water droplet amount threshold, the number of times threshold is set to a low value. Note that the wiper control unit 15 may set the number of times threshold or the water droplet amount threshold in multiple stages, not limited to two stages. As a result, when the amount of water droplets is large, the rear wiper can be automatically driven when the driver looks at the rearview mirror less times than when the amount of water droplets is small. Therefore, for example, when the amount of rain is small, it is possible to avoid cumbersome control such as always driving the rear wiper when the driver looks at the rearview mirror just once, and it is possible to easily drive the rear wiper automatically when the amount of rain is large. As a result, the rear wiper can be driven in accordance with the driver's intention.

[0024] The wiper control unit 15 may determine the wiper drive frequency according to the amount of water droplets. The wiper control unit 15 determines the wiper drive frequency so that the greater the amount of water droplets, the greater the wiper drive frequency. The drive frequency indicates the number of times the wiper is driven per relatively long period of time, such as one drive (one reciprocation) per three minutes. The greater the wiper drive frequency, the greater the number of times the wiper is driven per given period of time. The wiper control unit 15 includes information on the determined drive frequency in a control command and outputs the command to the rear wiper drive device 6. The wiper control unit 15 may change the wiper drive frequency according to the amount of water droplets while the wiper is being driven. Alternatively, the wiper control unit 15 may determine the rear wiper drive frequency before the driver gets into the vehicle. The water droplet determination unit 13 identifies the amount of water droplets from window information while the vehicle is stopped and the driver is not inside. The wiper control unit 15 may then determine the wiper drive frequency according to the amount of water droplets while the vehicle is stopped and the driver is not inside.

[0025] Next, the control procedure of the wiper control method executed by the controller 11 of the wiper control device 10 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing an example of the control procedure for executing the wiper control method according to this embodiment. The control flow in Fig. 3 can be executed not only while the vehicle 1 is stopped, but also while the vehicle 1 is traveling. The control flow in Fig. 3 is repeatedly executed at predetermined intervals. Furthermore, the control flow in Fig. 3 does not necessarily have to be executed in the order shown in Fig. 3, and not all steps necessarily have to be executed.

[0026] In step S1, the information acquisition unit 12 of the controller 11 acquires window information from the windshield water droplet detection device 2 or the like. In step S2, the water droplet determination unit 13 determines whether or not there are water droplets on the window glass based on the window information. If there are water droplets on the window glass, the water droplet determination unit 13 identifies the amount of water droplets. If there are no water droplets on the window glass, the controller 11 ends the control flow shown in Figure 3. At this time, if the rear wiper is operating, the controller 11 outputs a stop command to the rear wiper drive device 6 to stop driving the rear wiper.

[0027] If it is determined that there are water droplets on the window glass, in step S3, the information acquisition unit 12 acquires line-of-sight information from the interior camera 5. Note that the step of acquiring line-of-sight information may be performed before step S2. In step S4, the wiper control unit 15 sets a count threshold value according to the amount of water droplets.

[0028] In step S5, the line-of-sight determination unit 14 of the controller 11 determines whether the driver looks at the rearview mirror based on the line-of-sight information. Regarding the determination of whether the driver looks at the rearview mirror, the line-of-sight determination unit 14 may determine that the driver actually looks at the rearview mirror, or may determine that the driver looks at the rearview mirror based on a prediction that the driver will look at the rearview mirror before the driver actually looks at the rearview mirror. If it is determined that the driver is not looking at the rearview mirror, the controller 11 ends the control flow shown in FIG. 3.

[0029] When it is determined that the driver looks at the rearview mirror, the line-of-sight determination unit 14 calculates the number of times of looking by incrementing the number of times of looking. That is, the controller 11 performs the process of step S6 while repeatedly executing the control flow of Fig. 3, thereby continuously increasing the number of times of looking.

[0030] In step S7, the wiper control unit 15 compares the number of times of looking with the number threshold and determines whether the number of times of looking is equal to or greater than the number threshold. If the number of times of looking is less than the number threshold, the controller 11 ends the control flow shown in Fig. 3. If the number of times of looking is equal to or greater than the number threshold, the wiper control unit 15 outputs a drive command to drive the rear wiper to the rear wiper drive device 6. Then, the controller 11 ends the control flow shown in Fig. 3.

[0031] As described above, the wiper control device 10 and wiper control method according to this embodiment determine whether water droplets are present on the window glass based on window information, identify the amount of water droplets from the window information, calculate the number of times the driver looks at the rearview mirror based on line-of-sight information, set a count threshold according to the amount of water droplets, determine that water droplets are present on the window glass, and output a control command to activate the rear wiper if the calculated number of times the driver looks at the rearview mirror is equal to or greater than the count threshold. This allows the rear wiper to be activated in accordance with the driver's intention. It also prevents unnecessary activation of the rear wiper, reducing the annoyance to the driver caused by the rear wiper obstructing the view. Furthermore, on rainy days, the rear wiper can be automatically activated when needed simply by looking at the rearview mirror, without the driver having to manually operate it. Furthermore, because the rear wiper can be activated when needed based on the amount of rain, unnecessary activation of the rear wiper can be prevented, reducing the annoyance to the driver caused by the rear wiper obstructing the view.

[0032] When the amount of rain is low, for example, the driver may unintentionally look at the rearview mirror. In this way, when the amount of rain is low, the driver may unintentionally look at the rearview mirror only once or a few times, which is an accidental occurrence. In this embodiment, for example, when the amount of water droplets is equal to or less than the water droplet amount threshold, the controller 11 sets the number threshold to a low value. As a result, when the amount of rain is low, the rear wiper does not automatically operate even if the driver unintentionally looks at the rearview mirror. As a result, it is possible to prevent the rear wiper from automatically operating against the driver's intention.

[0033] In this embodiment, if it is determined that there are water droplets on the windshield and the calculated number of times is less than the threshold number, a control command to drive the rear wiper is not output. This allows the rear wiper to be driven when necessary depending on the amount of rain, thereby preventing unnecessary rear wiper drive and reducing the annoyance to the driver caused by the rear wiper blocking the view.

[0034] In this embodiment, the rear wiper drive frequency is determined according to the amount of water droplets, and a control command including the drive frequency information is output. This allows the rear wiper drive frequency to be adjusted according to the amount of water droplets. Furthermore, the rear wiper drive frequency can be adaptively changed based on the input information to the controller 11, reducing the annoyance and discomfort felt by the driver due to frequent automatic operation.

[0035] In this embodiment, the determination of whether the driver looks at the rearview mirror is performed by determining whether the driver's line of sight is directed toward the rearview mirror, thereby making it possible to determine whether the driver looks at the rearview mirror from the driver's line of sight.

[0036] In this embodiment, the direction of the driver's line of sight is identified from the line of sight information, and if the identified direction of movement is along a predetermined line of sight reference line, it is determined that the driver will look at the rearview mirror. The line of sight reference line is a line connecting a reference position and the installation position of the rearview mirror, the reference position is a predetermined reference position on the windshield in front of the driver's line of sight, and the installation position of the rearview mirror is a position on the windshield in front of the driver's line of sight when looking at the rearview mirror. This makes it possible to predict the destination of the driver's line of sight from the direction of the driver's line of sight, and to determine whether the driver will look at the rearview mirror before actually looking at it.

[0037] In this embodiment, the window information includes at least one of windshield wiper operation information indicating the operation status of the windshield wipers, detection information from a raindrop sensor that detects water droplets on the windshield, and an image of the windshield taken by an in-vehicle camera. This allows the raindrop condition on the rear window to be detected without installing a dedicated sensor near the rear window.

[0038] In a modification of this embodiment, the controller 11 may combine information on water droplets on the windshield and information on water droplets on the rear windshield to control the rear wiper. FIG. 3 is a flowchart showing an example of a control procedure for executing a wiper control method according to a modification of this embodiment. The control flow in FIG. 4 can be executed not only while the vehicle is stopped, but also while the vehicle is moving. The control flow in FIG. 4 is repeatedly executed at a predetermined interval. Furthermore, the control flow in FIG. 4 does not necessarily have to be executed in the order shown in FIG. 4, and not all steps necessarily have to be executed.

[0039] The control flow of step S11 is the same as the control flow of step S1 in Fig. 3. In step S12, the water droplet determination unit 13 of the controller 11 determines whether or not water droplets are present on the windshield based on the window information. The water droplet determination unit 13 determines whether or not water droplets are present on the windshield based on at least one of the front wiper drive information obtained from the front wiper drive device 3, the detection information of the windshield water droplet detection device 2, and the captured image of the windshield. mosquito If there are water droplets on the windshield, the water droplet determination unit 13 may identify the amount of water droplets. If there are no water droplets on the windshield, the controller 11 ends the control flow shown in Figure 4.

[0040] If it is determined that there are water droplets on the windshield, in step S13, The water droplet determination unit 13 of the controller 11 determines whether or not water droplets are present on the rear window based on the window information. The water droplet determination unit 13 determines whether or not water droplets are present on the rear window based on at least one of the detection information from the rear window water droplet detection device 4 and the captured image of the rear window. mosquito If there are water droplets on the rear window, the water droplet determination unit 13 may identify the amount of water droplets. If there are no water droplets on the rear window, the controller 11 ends the control flow shown in FIG.

[0041] If it is determined that water droplets are present on both the windshield and rear windshield, the controller 11 executes the control flow of steps S14 to S19. The control flow of steps S14 to S19 is the same as the control flow of steps S3 to S8 in Fig. 3. However, in the control flow of step S13, the amount of water droplets used to set the frequency threshold may be at least either the amount of water droplets on the windshield or the amount of water droplets on the rear windshield.

[0042] In a modification of this embodiment, the controller 11 may set the number threshold value according to the driving history of the rear wiper. For example, the controller 11 records the time when the rear wiper was last driven (or the time when the driving of the rear wiper was stopped) as the driving history of the rear wiper, and calculates the elapsed time from the last time the rear wiper was driven to the present. The present time is the timing when the control of step S1 in FIG. 3 is started, for example, the timing when the main switch of the vehicle (the ignition switch, the power switch of an electric vehicle, etc.) is turned on. If the elapsed time up to the present is less than the predetermined time threshold value, the controller 11 sets the number threshold value to a high value. On the other hand, if the elapsed time up to the present is equal to or greater than the predetermined time threshold value, the controller 11 sets the number threshold value to a high value. low Set to a value.

[0043] If the time elapsed since the last time the rear wiper was driven is short, the amount of raindrops on the rear windshield will have been wiped away by the previous drive of the rear wiper, and the demand for driving the rear wiper is likely to be low. Therefore, in this modified example, the shorter the elapsed time, the higher the number threshold is set to prevent the rear wiper from being driven too frequently. On the other hand, if the elapsed time is long, the number threshold is set to a low value to drive the rear wiper. Note that when setting the number threshold according to the rear wiper drive history, it is preferable that the controller 11 takes into account the amount of water droplets when setting the number threshold.

[0044] In a modified example of this embodiment, the controller 11 determines, based on window information, whether there are water droplets on at least one of the windshield and rear windshield and whether the front wiper is not operating. If the controller 11 determines that there are water droplets on at least one of the windshield and rear windshield and the front wiper is not operating, it does not output a control command to drive the rear wiper. For example, when washing a car, if there are water droplets on at least one of the windshield and rear windshield due to a factor other than rain and the front wiper is not operating, there is no need to drive the rear wiper. Therefore, in the modified example, centre If the front wipers are not operating and there are water droplets on either the windshield or rear windshield, the rear wiper will not be activated. This prevents the rear wiper from being activated by mistake, for example, when the driver is looking in the rearview mirror while washing the car.

[0045] Users can customize the rear wiper operation frequency and whether the wiper operation function is on or off, and the operation control program can be updated not only by reading solid-state memory elements such as CDs, DVDs, Blu-ray discs, and flash memory, but also via wireless communication such as FOTA and OTA. [Explanation of symbols]

[0046] 1...Vehicle 2...Windshield water droplet detection device 3...Front wiper drive unit 4...Rear window water droplet detection device 5...In-car camera 6...Rear wiper drive unit 10...Wiper control device 11...Controller 12…Information acquisition section 13...Water droplet determination section 14... Gaze determination section 15...Wiper control unit

Claims

1. A wiper control device including a controller for controlling a rear wiper, The controller Obtain window information about the vehicle's window glass, Acquires driver's gaze information, determining whether or not there are water droplets on the window glass based on the window information; Calculating the number of times the driver looks at the rearview mirror based on the line-of-sight information; When it is determined that water droplets are present on the window glass, the wiper control device outputs a control command to drive the rear wiper based on the calculated number of times and the line-of-sight information.

2. A wiper control device according to claim 1, The controller Identifying the amount of water droplets from the window information; A frequency threshold is set according to the amount of water droplets; The wiper control device determines that water droplets are present on the window glass, and outputs the control command when the calculated number of times is equal to or greater than the number threshold.

3. The wiper control device according to claim 2, The controller The wiper control device determines that water droplets are present on the window glass, and does not output the control command if the calculated number of times is less than the number threshold value.

4. The wiper control device according to claim 2, The controller determining a driving frequency of the rear wiper in accordance with the amount of water droplets; A wiper control device that outputs the control command including information on the drive frequency.

5. The wiper control device according to claim 4, The controller determines the frequency of driving the rear wiper before the driver gets into the vehicle.

6. The wiper control device according to claim 1 or 2, The controller The wiper control device determines whether the driver looks at the rearview mirror by determining whether the driver's line of sight is directed toward the position of the rearview mirror.

7. The wiper control device according to claim 1 or 2, The controller Identifying a direction of movement of the driver's line of sight from the line of sight information; If the movement direction is along a predetermined line of sight, it is determined that the driver looks at the rearview mirror; the line of sight reference line is a line connecting the first position and the second position, the first position is a predetermined reference position on a windshield in front of the driver's line of sight, The second position is a position on the windshield that is in the driver's line of sight when looking at the rearview mirror.

8. The wiper control device according to claim 7, The controller The wiper control device determines whether the driver will look at the rearview mirror based on the line-of-sight information before the driver actually looks at the rearview mirror.

9. The wiper control device according to claim 1 or 2, The window information includes at least one of front wiper drive information indicating the drive status of the front wipers, detection information from a raindrop sensor that detects raindrops on the front window, and an image of the window glass taken by an in-vehicle camera.

10. The wiper control device according to claim 1 or 2, The controller The wiper control device determines whether water droplets are on at least one of the windshield and the rear windshield and whether the front wiper is not moving, and does not output the control command to drive the rear wiper when it determines that water droplets are on at least one of the windshield and the rear windshield and the front wiper is not moving.

11. The wiper control device according to claim 2 or 3, The controller A wiper control device that sets the number threshold value in accordance with the driving history of the rear wiper.

12. A wiper control method executed by a controller that controls a rear wiper, The controller Obtain window information about the vehicle's window glass, Acquires driver's gaze information, determining whether or not there are water droplets on the window glass based on the window information; Calculating the number of times the driver looks at the rearview mirror based on the line-of-sight information; When it is determined that water droplets are present on the window glass, a control command to drive the rear wiper is output based on the calculated number of times and the line-of-sight information.

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