Cleaning device for road surface sensor unit for vehicle

Abstract

To provide a cleaning device for a road surface sensor unit for a vehicle, the cleaning device not using windshield washer fluid.SOLUTION: A cleaning device for a road surface sensor unit for a vehicle includes: a drain tank that stores drain water drained from an air conditioning system of the vehicle; a drain outlet that drains the drain water drained from the drain tank to a front side of a detection surface of the road surface sensor unit; a valve member that opens and closes the drain outlet; a control unit; and a road surface detection member that senses or detects a road surface being traveled on. The control unit keeps the valve member closed while the vehicle is in operation, and opens the valve member for a fixed period of time when the vehicle speed after traveling on a rough road is detected to be equal to or greater than a predetermined value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a cleaning device for a road surface sensor unit for a vehicle. [Background technology]

[0002] As disclosed in Patent Documents 1 and 2, a vehicle may be provided with a sensor on the bottom of the vehicle body that detects the road surface. Patent document 1 discloses a ground speed sensor. Patent document 2 discloses a device for detecting surface condition data, which comprises a radiation emitter and a detector for detecting radiation reflected from the road surface. The road surface sensor unit is provided on the bottom of the vehicle body facing the road surface, and is therefore easily soiled with dust and mud.

[0003] If the detection surface of the road surface sensor unit becomes dirty, it may become unable to correctly detect the road surface condition. For this reason, Patent Documents 1 and 2 disclose a cleaning device for cleaning the road surface sensor unit. In Patent Document 1, when the vehicle is stopped in the rain or when the ignition switch is turned off after driving in the rain, windshield washer fluid from the vehicle's washer fluid tank is sprayed onto the ground speed sensor. In Patent Document 2, windshield washer fluid is sprayed onto the detection device when the driver uses the windshield washer fluid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 62-162667 [Patent Document 2] Special Publication No. 2006-523336 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even if windshield washer fluid is sprayed onto the road sensor unit when driving in the rain, the detection surface of the road sensor unit may become dirty. For example, when driving on a rough road after a rainy day and then clearing up, the detection surface of the road sensor unit may become dirty when passing through puddles. The detection surface of the road sensor unit does not only become dirty while driving in the rain. Furthermore, if the detection surface of the road sensor unit is left dirty, the dirt may dry and become fixed to the detection surface. Once the dirt has become fixed in this way, it becomes difficult to remove the dirt from the detection surface by simply spraying windshield washer fluid. If one were to try to remove the dirt that has stuck to the detection surface by spraying windshield washer fluid alone, a large amount of windshield washer fluid would have to be sprayed.

[0006] Furthermore, in Patent Documents 1 and 2, the vehicle's windshield washer fluid is used to clean the road surface sensor unit. Windshield washer fluid contains detergent and the like. Therefore, if a large amount of windshield washer fluid is used to clean the road surface sensor unit, the environmental impact may be considered a problem. In particular, if windshield washer fluid is sprayed onto the road surface sensor unit at regular intervals when the brakes are not being operated, as in Patent Document 1, a large amount of windshield washer fluid will be used to clean the road surface sensor unit.

[0007] Furthermore, windshield washer fluid is replenished by a person in a vehicle. If windshield washer fluid is used to clean the road surface sensor unit as in Patent Documents 1 and 2, the frequency of replenishing windshield washer fluid increases.

[0008] Thus, there is a need for improvements in the cleaning device for cleaning the road surface sensor unit. [Means for solving the problem]

[0009] A cleaning device for a vehicle road surface sensor unit in one embodiment of the present invention comprises a road surface sensor unit arranged on the bottom of the vehicle body forward of the vehicle's front wheels, facing the road surface; a drain tank for storing drain water from the vehicle's air conditioning system; a drain outlet arranged forward of the detection surface of the road surface sensor unit in the vehicle's traveling direction and for draining drain water from the drain tank; a valve member for draining or stopping the drain water from the drain outlet; a control unit for controlling the opening and closing of the valve member; and a road surface detection member for detecting or sensing the road surface on which the vehicle is traveling, wherein the control unit keeps the valve member closed while the vehicle is operating, and opens the valve member for a certain period of time when, based on the detection or sensing of the road surface detection member, the vehicle detects or senses a vehicle speed above a predetermined value after traveling on a rough road. [Effects of the Invention]

[0010] In this invention, drain water from a vehicle's air conditioning system is stored in a drain tank and used to clean the road surface sensor unit. The drain water from the air conditioning system is based on moisture in the air and does not contain detergents, etc. This does not pose an environmental burden. Furthermore, there is no need to replenish the drain water.

[0011] In addition, in the present invention, the drain outlet for draining the drain water from the drain tank is provided forward of the detection surface of the road surface sensor unit in the direction of vehicle travel. Also, the control unit closes the valve member to stop drain water from the drain outlet while the vehicle is in operation. This allows drain water generated by vehicle operation to accumulate in the drain tank. The control unit opens the valve member for a fixed period of time when the control unit detects or senses that the vehicle speed is equal to or greater than a predetermined value after the vehicle has traveled on a rough road. This causes a temporary flow of drain water to form in front of the road sensor unit. Because the vehicle speed is equal to or greater than the predetermined value, the detection surface of the road sensor unit plunges into the flow of drain water formed in front of the road sensor unit. This allows dirt on the detection surface of the road sensor unit to be completely removed. In particular, as in the present invention, by removing dirt when the vehicle speed increases after driving on a rough road, even if the detection surface of the road surface sensor unit becomes dirty after passing through a puddle or the like while driving on a rough road, the dirt can be quickly removed before it hardens. As a result, in the present invention, even if the vehicle travels on a rough road, the detection surface of the road surface sensor unit can be immediately cleaned of dirt thereafter, thereby keeping the detection surface of the road surface sensor unit clean, and the road surface sensor unit can function properly even after traveling on a rough road.

[0012] Moreover, in the present invention, the timing of cleaning with drain water is limited. As a result, the detection surface of the road surface sensor unit can be kept essentially dry, compared to when cleaning with drain water at regular intervals, for example. If water droplets adhere to the detection surface of the road surface sensor unit, the detection performance may be reduced.

[0013] In this way, the present invention can maintain the detection surface of the road surface sensor unit in a state that is neither dirty nor wet, and can effectively prevent a decrease in detection performance. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an explanatory diagram of a driving state of an automobile. [Figure 2] FIG. 2 is a configuration diagram of a cleaning device for a road surface sensor unit for a vehicle according to an embodiment of the present invention, which is applied to the automobile shown in FIG. [Figure 3] FIG. 3 is a flowchart of the cleaning control executed by the control unit of FIG. [Figure 4] FIG. 4 is an explanatory diagram of a cleaning state in which drain water is being discharged while the automobile is running in this embodiment. [Figure 5] FIG. 5 is an explanatory diagram of a cleaning state in which drain water is being discharged immediately after the automobile has changed from a running state to a non-running state. [Figure 6]FIG. 6 is simply an explanatory diagram showing a state in which drain water is being discharged from the cleaning device of FIG. [Figure 7] FIG. 7 is a flowchart of the antifouling control that the control unit in FIG. 2 executes together with the cleaning control in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] FIG. 1 is an explanatory diagram of a driving state of an automobile 1. As shown in FIG. The automobile 1 is an example of a vehicle. In Fig. 1, automobile 1 is traveling from a rough road 52 toward a paved road 51. A puddle 53 has formed in a depression in the rough road 52, which is an unpaved road. In this case, automobile 1 passes through puddle 53 while traveling on the rough road, and then exits rough road 52 and travels on paved road 51.

[0017] Incidentally, the running of the automobile 1 changes depending on the condition of the road surface. For example, the ease with which the wheels of the automobile 1 slip on the road surface varies greatly between a dry paved road 51 and a wet rough road 52. For this reason, it is conceivable to provide the automobile 1 with a road surface sensor unit 11 that detects the road surface, as shown by the dashed line in Fig. 1. The road surface sensor unit 11 is installed on the bottom of the body of the automobile 1 facing the road surface in order to observe the road surface. The road surface sensor unit 11 detects the road surface condition by irradiating the road surface with near-infrared laser light and measuring the reflected light. The road surface sensor unit 11 can detect road surface conditions such as dry, frozen, snowy, wet, slush, and frost.

[0018] However, because such a road sensor unit 11 is installed on the bottom of the vehicle body, the detection surface is easily soiled by dust and mud. The detection surface of the road sensor unit 11 does not only become soiled when driving in the rain. As shown in FIG. 1, even when driving on a rough road 52 on a sunny day after rain, the detection surface of the road sensor unit 11 can become soiled when passing through a puddle 53 or the like. If the detection surface of the road sensor unit 11 is left soiled, dried dirt may adhere to the detection surface. Once the dirt adheres, it becomes difficult to remove the dirt from the detection surface. Furthermore, the road surface sensor unit 11 may be unable to correctly detect the road surface condition if the detection surface becomes dirty. Also, the road surface sensor unit 11 may be unable to correctly detect the road surface condition if the detection surface is wet.

[0019] As described above, the cleaning device 10 for cleaning the road surface sensor unit 11 is required to be improved.

[0020] FIG. 2 is a configuration diagram of a cleaning device 10 for a road surface sensor unit 11 for a vehicle according to an embodiment of the present invention, which is applied to the automobile 1 of FIG. The cleaning device 10 for the road surface sensor unit 11 in FIG. 2 includes the road surface sensor unit 11 for a vehicle, an air conditioner 12, a drain duct 13, a drain tank 14, a drain nozzle 15, a valve member 16, an air conditioning duct 17, and a control unit 20.

[0021] The road surface sensor unit 11 has a cylindrical member 31, a member 32 for irradiating near-infrared laser light, a measuring member 33 for measuring the light of the near-infrared laser light reflected by the road surface, and a detection surface member . The cylindrical tubular member 31 has a cylindrical shape. The cylindrical inner surface of the cylindrical member 31 may be black to suppress reflection of laser light. The cylindrical tubular member 31 is provided on the automobile 1 in a position that is oblique to the up-and-down direction of the automobile 1. Specifically, the cylindrical tubular member 31 is provided on the bottom of the vehicle body forward of the front wheels 43 of the automobile 1 in a position that slopes downward toward the road surface.

[0022] The irradiation member 32 and the measurement member 33 are arranged side by side at the upper end of the cylindrical member 31, which is arranged in a forward-slanting position. The irradiation member 32 irradiates near-infrared laser light in the axial direction of the cylindrical member 31. The near-infrared laser light is reflected by the road surface in the axial direction of the cylindrical member 31. The measurement member 33 receives the reflected component of the laser light reflected along the axial direction of the cylindrical member 31. This allows the measurement member 33 of the road surface sensor unit 11 to observe the road surface condition while suppressing the influence of scattered light components of the laser light and natural light components. The measurement results of the measurement member 33 can accurately detect the condition of the measured portion of the road surface, i.e., road surface conditions such as dry, frozen, snow-covered, wet, slush, and frost.

[0023] The detection surface member 34 is provided at the lower end of the cylindrical member 31, which is provided in a position where the front is downwards. The detection surface member 34 is preferably formed from a material that transmits near-infrared laser light well. This isolates the interior of the cylindrical member 31, which is used outdoors, from the outside world. This makes it difficult for dust and dirt to enter the interior of the cylindrical member 31. If the interior of the cylinder becomes dirty, the measurement performance of the road surface sensor unit 11 will be reduced due to scattering, etc.

[0024] The road surface sensor unit 11 is provided on the bottom of the body of the automobile 1, in a position forward of the front wheels 43 of the automobile 1, in an oblique position with its front side downwards toward the road surface.

[0025] The air conditioner 12 is an air conditioner 12 for the passenger compartment of the automobile 1. The air conditioner 12 of the automobile 1 has a compressor, a condenser, a receiver, an evaporator, an air conditioning duct 17, a fan, etc. The heat medium compressed by the compressor is condensed in the receiver by the condenser, and heat is exchanged in the evaporator in the air conditioning duct 17. The airflow generated by the fan from the air conditioning duct 17 is adjusted in temperature or humidity by the evaporator and supplied to the passenger compartment of the automobile 1. In the air conditioner 12, the moisture in the air used for air conditioning is liquefied in the evaporator. A drain duct 13 is connected to the air conditioner 12 to discharge this moisture.

[0026] The drain tank 14 is connected to the drain duct 13 of the air conditioner 12. The drain tank 14 stores drain water from the air conditioner 12. In FIG. 1, the drain tank 14 is arranged below the air conditioner 12. In this case, the drain water from the air conditioner 12 flows naturally through the drain duct 13 and can accumulate in the drain tank 14. Depending on the arrangement of the air conditioner 12 in the automobile 1, it may be difficult to arrange the drain tank 14 below the air conditioner 12. In this case, it is advisable to provide a pump in the drain duct 13. The drain tank 14 is disposed in the engine compartment 40 of the automobile 1 together with the road surface sensor unit 11. Heat sources such as an engine 41 and a radiator 42 are disposed in the engine compartment 40 of the automobile 1. For this reason, the temperature of the engine compartment 40 becomes higher than the outside air temperature while the automobile 1 is running. The drain water that accumulates in the drain tank 14 in the engine compartment 40 does not freeze while the automobile 1 is running.

[0027] A drain nozzle 15 is provided on the underside of the drain tank 14. The drain nozzle 15 is provided on the front side of the vehicle 1 relative to the detection surface member 34 of the road surface sensor unit 11, which is provided in an oblique position with its front downward toward the road surface. The drain outlet at the bottom of the drain nozzle 15 is located on the upper front side of the detection surface member 34 of the road surface sensor unit 11. As a result, drain water accumulated in the drain tank 14 is drained downward from a position on the upper front side of the detection surface member 34 of the road surface sensor unit 11. The drain water can be drained in a curtain-like manner from the detection surface member 34 of the road surface sensor unit 11 on the front side in the direction of vehicle travel.

[0028] The valve member 16 is provided for the drain outlet of the drain nozzle 15 and opens and closes the drain outlet. When the valve member 16 is closed, the drain outlet is blocked. Drainage from the drain outlet stops and the drain tank 14 can store drain water. When the valve member 16 is open, the drain outlet is open. Drain water stored in the drain tank 14 is drained downward from the drain outlet of the drain nozzle 15.

[0029] The air conditioning duct 17 is connected to the air conditioning duct 17 of the air conditioner 12. The lower end of the air conditioning duct 17 is provided further forward of the vehicle 1 than the drain outlet of the drain nozzle 15. The lower end of the air conditioning duct 17, the drain outlet of the drain nozzle 15, and the detection surface member 34 of the road surface sensor unit 11 may be aligned in a straight line along the fore-and-aft direction of the vehicle 1 when viewed from above. This allows the air conditioning duct 17 to exhaust the conditioned airflow toward the lower side of the drain outlet of the drain nozzle 15 when the air conditioner 12 is operating. Note that the air conditioning duct 17 may also be provided with another valve member 16.

[0030] The control unit 20 controls the operation of the washing device 10 of the road surface sensor unit 11. For example, an exterior camera 21, a vehicle speed sensor 22, an ignition switch 23, a timer 24, etc. are connected to the control unit 20. In addition to these, for example, a GNSS (Global Navigation Satellite System) receiver, a memory for recording high-precision map data, a LiDAR (Light Detection and Ranging), etc. may also be connected to the control unit 20. These devices and the control unit 20 of the washing device 10 may be connected via a vehicle network provided in the automobile 1.

[0031] The exterior camera 21 captures images of the surroundings including the front side, which is the traveling direction of the automobile 1. The image captured by the exterior camera 21 captures the road surface in front, which is the traveling direction of the automobile 1. In the case of FIG. 1, the exterior camera 21 captures images of puddles 53 on a rough road 52 and a paved road 51. In this way, the outside camera 21 functions as a road surface detection member that detects the road surface on which the automobile 1 is traveling.

[0032] The vehicle speed sensor 22 detects or senses the vehicle speed of the automobile 1 . The vehicle speed sensor 22 may be one that detects or senses the physical speed of the automobile, or one that detects or senses the speed of the automobile 1 by calculation, like a GNSS receiver.

[0033] The ignition switch 23 is a switch that is operated to switch the automobile 1 between a running state and a non-running state. When the ignition switch 23 is operated from an off state to an on state, the engine 41 of the automobile 1 starts and the automobile 1 enters a running state. When the ignition switch 23 is operated from an on state to an off state, the engine 41 of the automobile 1 stops and the automobile 1 enters a non-running state.

[0034] The timer 24 measures time and hour.

[0035] The control unit 20 controls the opening and closing of the valve member 16 according to the state of the automobile 1.

[0036] FIG. 3 is a flowchart of the cleaning control executed by the control unit 20 of FIG. The control unit 20 in FIG. 2 repeatedly executes the cleaning control in FIG.

[0037] In step ST1, the control unit 20 determines whether the ignition switch 23 is in the on state. If the ignition switch 23 is not in the ON state, that is, if the ignition switch 23 is in the OFF state, the control unit 20 repeats this process. If the ignition switch 23 is in the on state, the control unit 20 advances the process to step ST2.

[0038] In step ST2, the control unit 20 closes the valve member 16. As will be described later, the valve member 16 is maintained in an open state when the ignition switch 23 is in an off state. This allows the drain tank 14 to be emptied while the automobile 1 is stopped. The control unit 20 closes the valve member 16 while the air conditioner 12 of the automobile 1 is operating, thereby allowing the drain tank 14 to store drain water from the air conditioner 12.

[0039] In step ST3, the control unit 20 determines whether the automobile 1 is traveling on a rough unpaved road 52. The control unit 20 may determine whether the automobile 1 is traveling on a rough unpaved road 52 based on an image captured by the exterior camera 21. In addition, the control unit 20 may determine whether the automobile 1 is traveling on a rough unpaved road 52 based on spatial information about the surroundings of the vehicle obtained by LiDAR, rather than or in addition to the image captured by the exterior camera 21. Furthermore, the control unit 20 may further use the GNSS receiver and high precision map data to determine whether the automobile 1 is traveling on a rough unpaved road 52 included in the high precision map data. If the automobile 1 is traveling on a rough unpaved road 52, the control unit 20 advances the process to step ST4. On the other hand, if the automobile 1 is traveling on a paved road 51 or the like, the control unit 20 advances the process to step ST12.

[0040] In step ST4, the control unit 20 determines whether the automobile 1 is traveling on a paved road 51. The control unit 20 may determine whether the automobile 1 is traveling on a paved road 51 based on an image captured by the exterior camera 21. In addition, the control unit 20 may determine whether the automobile 1 is traveling on a paved road 51 based on spatial information about the surroundings of the vehicle obtained by LiDAR, rather than or in addition to the image captured by the exterior camera 21. Furthermore, the control unit 20 may further use the GNSS receiver and high precision map data to determine whether the automobile 1 is traveling on a paved road 51 of the high precision map data. If the control unit 20 determines that the automobile 1 is not traveling on a paved road 51, the control unit 20 advances the process to step ST5. On the other hand, if it is determined that the automobile 1 is traveling on a paved road 51, the control unit 20 advances the process to step ST6.

[0041] In step ST5, the control unit 20 determines whether the ignition switch 23 is in the OFF state. If the ignition switch 23 is not in the OFF state, that is, if it is in the ON state, the control unit 20 returns the process to step ST4. On the other hand, if the ignition switch 23 is in the OFF state, the control unit 20 advances the process to step ST13. Immediately after the process proceeds from step ST3 to step ST4, the automobile 1 is basically traveling on a rough unpaved road 52. In this case, the control unit 20 determines that the automobile 1 is not traveling on a paved road 51, and repeats the processes of steps ST4 and ST5. Thereafter, when the automobile 1 moves from the rough road 52 in FIG. 1 to the paved road 51, the control unit 20 determines that the automobile 1 is traveling on the paved road 51, and proceeds to step ST6.

[0042] In step ST6, the control unit 20 determines whether the vehicle speed of the automobile 1 is equal to or greater than a threshold speed. Here, the threshold speed may be, for example, 40 km / h. When the vehicle speed reaches approximately 40 km / h, water droplets adhering to the detection surface of the road surface sensor unit 11, which is provided obliquely on the underside of the body of the automobile 1, tend to run off the detection surface. If the control unit 20 determines that the speed of the automobile 1 is not equal to or greater than the threshold speed, the control unit 20 advances the process to step ST7. On the other hand, if it is determined that the speed of the automobile 1 is equal to or greater than the threshold speed, the control unit 20 advances the process to step ST8.

[0043] In step ST7, the control unit 20 determines whether the ignition switch 23 is in the OFF state. If the ignition switch 23 is not in the OFF state, that is, if it is in the ON state, the control unit 20 returns the process to step ST6. On the other hand, if the ignition switch 23 is in the OFF state, the control unit 20 advances the process to step ST13. Immediately after the process proceeds from step ST4 to step ST6, the automobile 1 is basically just past a rough unpaved road 52. The automobile 1 increases its speed on the paved road. Then, when the speed of the automobile 1 reaches or exceeds the threshold speed, the control unit 20 causes the process to proceed to step ST8.

[0044] In step ST8, the control unit 20 causes the timer 24 to start measuring the elapsed time.

[0045] In step ST9, the control unit 20 opens the valve member 16. As a result, the drain water accumulated in the drain tank 14 is drained from the drain nozzle 15. A curtain-like wall of water may be formed by the drain water in front of the detection surface of the road surface sensor unit 11. Because the automobile 1 is traveling at the threshold speed, the curtain-like wall of water by the drain water flows toward the rear of the automobile 1 and can hit the detection surface of the road surface sensor unit 11.

[0046] In step ST10, the control unit 20 determines whether or not the elapsed time measured by the timer 24 is equal to or greater than a threshold time, which may be several seconds. If the elapsed time is not equal to or greater than the threshold time, the control unit 20 repeats this process. When the elapsed time reaches or exceeds the threshold time, the control unit 20 advances the process to step ST11.

[0047] In step ST11, the control unit 20 closes the valve member 16. As a result, a curtain-like water wall of drain water continues to be formed in front of the detection surface of the road surface sensor unit 11 during the period from step ST9 to step ST11. When the automobile 1 is traveling on a paved road after traveling on a rough road, the control unit 20 opens the valve member 16 for a certain period of time if it detects or senses a vehicle speed equal to or greater than a threshold speed value that is not used when traveling on a rough road.

[0048] In step ST12, the control unit 20 determines whether the ignition switch 23 is in the OFF state. If the ignition switch 23 is not in the OFF state, that is, if it is in the ON state, the control unit 20 returns the process to step ST3. That is, the control unit 20 basically maintains the valve member 16 in the closed state during the period from when the control unit 20 closes the valve member 16 in step ST2 until when the control unit 20 determines that the ignition switch 23 is in the OFF state in step ST12. Furthermore, if the vehicle is traveling on a rough road during that period, the control unit 20 opens the valve member 16 for a certain period of time while the vehicle is traveling on a paved road after traveling on the rough road. If the ignition switch 23 is in the OFF state, the control unit 20 advances the process to step ST13.

[0049] From step ST13, the control unit 20 starts processing when the ignition switch 23 is in the OFF state and the automobile 1 is parked. The control unit 20 first extends the operation of the air conditioner 12. The air conditioner 12 basically operates while there are occupants in the automobile 1. Note that if the air conditioner 12 is stopped while the automobile 1 is traveling, the control unit 20 may extend the operation of the air conditioner 12 by operating the air conditioner 12. As a result, after the ignition switch 23 is turned off, conditioned air is exhausted from the exhaust port of the air conditioning duct 17 of the parked automobile 1.

[0050] In step ST14, the control unit 20 causes the timer 24 to start measuring the elapsed time.

[0051] In step ST15, the control unit 20 opens the valve member 16. As a result, the drain water accumulated in the drain tank 14 is drained from the drain nozzle 15. In front of the detection surface of the road surface sensor unit 11, a curtain-like water wall may be formed by the drain water. Furthermore, since the air conditioner 12 is operating, the curtain-like water wall of drain water flows toward the rear of the automobile 1 and can hit the detection surface of the road surface sensor unit 11. In this way, after the automobile 1 changes from a running state in which the engine 41 is operating to a non-running state in which the engine 41 is stopped, the control unit 20 opens the valve member 16 while continuing to operate the air conditioning device 12 of the automobile 1 without stopping it.

[0052] In step ST16, the control unit 20 determines whether or not the time measured by the timer 24 is equal to or longer than a predetermined time. Here, the predetermined time may be from a few seconds to a few minutes. If the measured time is not equal to or longer than the predetermined time, the control unit 20 repeats this process. When the measured time reaches or exceeds the predetermined time, the control unit 20 advances the process to step ST17.

[0053] In step ST17, the control unit 20 turns off the air conditioner 12 that has been operating in an extended mode. As a result, the curtain-like water wall of drain water formed in front of the detection surface of the road surface sensor unit 11 continues to hit the detection surface of the road surface sensor unit 11 during the period from step ST3 to step ST17. Thereafter, the control unit 20 ends this control. In this way, the control unit 20 maintains the valve member 16 in an open state when the engine 41 of the automobile 1 is stopped and the automobile 1 is not running. Thereafter, in the processing of step ST2, the control unit 20 closes the valve member 16 when the engine 41 of the automobile 1 starts and the automobile 1 begins to run.

[0054] FIG. 4 is an explanatory diagram of a cleaning state in which drain water is being discharged while the automobile 1 is running in this embodiment. 3, the drain water flows rearward due to the running wind and hits the detection surface of the road surface sensor unit 11. Dust and mud adhering to the detection surface of the road surface sensor unit 11 can be washed away by the drain water. In particular, in this embodiment, the road surface sensor unit 11 is disposed with its front sloped downward. Therefore, the detection surface member 34 of the road surface sensor unit 11 has a surface that slopes downward toward the rear. The detection surface member 34 with its rear sloped downward is plunged entirely into the drain water. As a result, the dust and mud adhering to the detection surface member 34 of the road surface sensor unit 11 becomes wet in the short time from step ST9 to step ST11, and can efficiently flow off the entire surface of the detection surface member 34. Furthermore, water droplets are unlikely to remain on the detection surface member 34 thereafter. In this way, by using the wind generated by running and by using appropriate positioning, dust and mud adhering to the detection surface member 34 of the road surface sensor unit 11 can be efficiently removed from the entire surface of the detection surface member 34. Furthermore, after the detection surface member 34 of the washed road surface sensor unit 11 has been completely cleaned, it immediately dries and can return to a state in which it can correctly detect road surface conditions.

[0055] FIG. 5 is an explanatory diagram of a cleaning state in which drain water is being discharged immediately after the automobile 1 has changed from a traveling state to a non-traveling state. 3, during the non-driving state period from step ST15 to step ST2, the drain water flows rearward with the conditioned air discharged from the exhaust port of the air conditioner 12 and hits the detection surface of the road surface sensor unit 11. Dust and mud adhering to the detection surface of the road surface sensor unit 11 can be washed away by the drain water. In particular, in this embodiment, the road surface sensor unit 11 is disposed with its front sloped downward. Therefore, the detection surface member 34 of the road surface sensor unit 11 has a surface that slopes downward toward the rear. As a result, dust and mud adhering to the detection surface member 34 of the road surface sensor unit 11 are wetted in the short time from step ST15 to step ST17, and can efficiently flow off from the entire surface of the detection surface member 34. Furthermore, water droplets are unlikely to remain on the detection surface member 34 after that. In this way, dust and mud adhering to the detection surface member 34 of the road surface sensor unit 11 can be efficiently removed from the entire surface of the detection surface member 34 by the airflow from the air conditioner 12 and by using clever placement.

[0056] FIG. 6 is simply an explanatory diagram showing a state in which drain water is being discharged from the cleaning device 10 of FIG. When there is no wind from traveling or air from the air conditioner 12, for example, during the period from step ST17 to step ST2, the drain water is separated in front of the detection surface of the road surface sensor unit 11 and flows down without hitting the detection surface of the road surface sensor unit 11. The detection surface of the road surface sensor unit 11 is not exposed to drain water. Even if a large amount of drain water has accumulated in the drain tank 14 in step ST15, after the air conditioner 12 is controlled to be turned off, the drain water can be prevented from hitting the detection surface of the road surface sensor unit 11. The detection surface of the road surface sensor unit 11 does not remain wet forever. In this way, the cleaned detection surface member 34 immediately becomes dry after the dirt has been completely removed by cleaning, and can return to a state in which it can correctly detect the road surface condition. When the ignition switch 23 is turned on in step ST1, the detection surface member 34 of the road surface sensor unit 11 is basically in a dry state and is in a state in which it can correctly detect the road surface condition.

[0057] FIG. 7 is a flowchart of the antifouling control that the control unit 20 in FIG. 2 executes together with the cleaning control in FIG. The control unit 20 in FIG. 2 repeatedly executes the antifouling control in FIG. 7 together with the cleaning control in FIG.

[0058] In step ST21, the control unit 20 determines whether the automobile 1 will pass through a puddle. The exterior camera 21 can sense or detect a puddle 53 by capturing an image of the puddle 53 in the path of the automobile 1. The control unit 20 may determine whether the automobile 1 will pass through the puddle 53 based on the image captured by the exterior camera 21. If there is no puddle 53 in the path of the automobile 1, the control unit 20 repeats this process. If there is a puddle 53 in the path of the automobile 1, the control unit 20 advances the process to step ST22.

[0059] In step ST22, the control unit 20 calculates the timing at which the front wheels 43 of the automobile 1 will pass through the puddle 53. The puddle 53 is captured in an image captured by the exterior camera 21 at a location that corresponds to the relative distance and relative direction from the automobile 1. The control unit 20 calculates the distance from the automobile 1 to the puddle 53 based on the position and range of the sand sculpture portion of the puddle 53 in the captured image. The control unit 20 subtracts the current vehicle speed from the distance to the puddle 53 to calculate the timing at which the front wheels 43 of the automobile 1 will pass through the puddle 53.

[0060] In step ST23, the control unit 20 sets the timer 24 to the passage time calculated in step ST22.

[0061] In step ST24, the control unit 20 determines whether the time measured by the timer 24 is the passing time calculated in step ST22. If the time measured by the timer 24 is not the passing time calculated in step ST22, the control unit 20 repeats this process. When the time measured by the timer 24 reaches the passing time calculated in step ST22, the control unit 20 advances the process to step ST25.

[0062] In step ST25, the control unit 20 opens the valve member 16. As a result, the drain water accumulated in the drain tank 14 is drained from the drain nozzle 15. A curtain-like wall of water may be formed by the drain water in front of the detection surface of the road surface sensor unit 11. Furthermore, since the automobile 1 is moving, the curtain-like wall of water by the drain water may flow toward the rear of the automobile 1 and hit the detection surface of the road surface sensor unit 11.

[0063] In step ST26, the control unit 20 determines whether the time measured by the timer 24 is equal to or greater than the sum of the passage time and a predetermined threshold time. Here, the predetermined threshold time may be the same as that used in step ST10, for example. If the time measured by the timer 24 is not equal to or greater than the sum time, the control unit 20 repeats this process. When the time measured by the timer 24 becomes equal to or greater than the sum time, the control unit 20 advances the process to step ST27.

[0064] In step ST27, the control unit 20 closes the valve member 16. As a result, during the period from step ST25 to step ST27, the detection surface of the road surface sensor unit 11 can be washed away by the drain water. When the front wheels 43 of the automobile 1 pass through the puddle 53, splashed-up water droplets may adhere to the detection surface of the road surface sensor unit 11. However, in this embodiment, the detection surface of the road surface sensor unit 11 is washed away with drain water at that timing. Even if residues such as mud temporarily adhere to the detection surface of the road surface sensor unit 11 due to splash-up water from the puddle 53, they can be washed away with drain water immediately thereafter.

[0065] As described above, in this embodiment, drain water from the air conditioner 12 of the automobile 1 is stored in the drain tank 14 and used to wash the road surface sensor unit 11. The drain water from the air conditioner 12 is based on the moisture in the air and does not contain detergents or the like. Unlike when windshield washer fluid is used to wash the detection surface of the road surface sensor unit 11, there is no problem with environmental impact. Furthermore, there is no need to replenish the drain water. Moreover, in this embodiment, the drain outlet for draining the drain water from the drain tank 14 is provided ahead of the detection surface of the road surface sensor unit 11 in the direction of travel of the vehicle. Furthermore, the control unit 20 closes the open / close valve member 16 to stop drain water from the drain outlet while the air conditioner 12 of the automobile 1 is operating. This causes drain water resulting from the operation of the air conditioner 12 of the automobile 1 to accumulate in the drain tank 14. When the air conditioner 12 is operated at high speed in the summer, the amount of drain water may reach several hundred cc per hour. The control unit 20 opens the valve member 16 for a certain period of time when the control unit 20 detects or senses that the vehicle speed of the vehicle 1 is equal to or greater than a predetermined value after traveling on a rough road. This causes a continuous curtain-like flow of water to temporarily form in front of the road sensor unit 11. Because the vehicle speed of the vehicle 1 is equal to or greater than a threshold speed that is not used when traveling on a rough road, the detection surface of the road sensor unit 11 plunges into the continuous curtain-like flow of water formed in front of the road sensor unit 11. This is expected to effectively remove dirt from the detection surface of the road sensor unit 11. In particular, by removing dirt when the vehicle speed increases after traveling on a rough road, as in this embodiment, even if the detection surface of the road sensor unit 11 becomes dirty after passing through a puddle 53 or the like while traveling on a rough road, it is expected that the dirt can be quickly removed before it hardens. As a result, in this embodiment, even if the automobile 1 travels on a rough road, dirt is immediately removed from the detection surface of the road surface sensor unit 11 after the travel, so that the detection surface of the road surface sensor unit 11 can be kept clean. The road surface sensor unit 11 can function properly even after traveling on a rough road.

[0066] Moreover, in this embodiment, the timing for draining the drain water is limited. As a result, the detection surface of the road surface sensor unit 11 is kept dry compared to, for example, a case where drain water is sprayed at regular intervals. When water droplets adhere to the detection surface of the road surface sensor unit 11, the detection performance may be reduced, just as when the detection surface is dirty with mud or other contaminants. In this embodiment, the detection surface of the road surface sensor unit 11 can be kept neither dirty nor wet, and the reduction in detection performance can be effectively suppressed.

[0067] In particular, in this embodiment, the road surface sensor unit 11 has a cylindrical tubular member 31, which is arranged with its front lowered in the longitudinal direction of the automobile. An irradiation member 32 for emitting near-infrared laser light and a measurement member 33 for measuring reflected light of the near-infrared laser light from the road surface are provided at the upper end of the tubular member 31 of the road surface sensor unit 11, in the direction toward the top of the automobile 1, and a detection surface member 34 constituting the detection surface of the road surface sensor unit 11 is provided at the lower end, in the direction toward the bottom of the automobile 1. As a result, the entire detection surface of the road sensor unit 11, which is disposed at an angle facing downward and forward, is thrust directly into the continuous curtain-like flow of water formed in front of the road sensor unit 11. The entire detection surface of the road sensor unit 11 can be wetted by the flow of water. The detection surface of the road sensor unit 11 is directly exposed to the entire surface of the continuous curtain-like flow of water formed by opening the valve member 16 for a certain period of several seconds, and becomes wet, so that dirt can be removed from the entire surface. In contrast to this, if the detection surface member 34, which prevents the irradiation member 32 and the measurement member 33 from getting dirty, is provided facing downward in the vertical direction of the automobile 1, the detection surface of the road sensor unit 11 will be a surface that follows the longitudinal direction of the automobile 1. In this case, even if a continuous curtain-like flow of water is formed in front of the road sensor unit 11, only a portion of the front end of the detection surface of the road sensor unit 11 will be partially wet. Dirt is likely to remain on the detection surface of the road sensor unit 11.

[0068] In this embodiment, the exhaust port of the air conditioning device 12 of the automobile 1 is located closer to the front of the automobile 1 than the drain port. After the automobile 1 transitions from a running state in which the engine 41 is running to a non-running state in which the engine 41 is stopped, the control unit 20 continues to operate the air conditioning device 12 of the automobile 1 without stopping it, exhausting conditioned air from the exhaust port while opening the valve member 16. This allows the road surface sensor unit 11 to be cleaned every time the automobile 1 transitions to a non-running state. Even when the automobile 1 is traveling only on paved roads 51 and not on rough roads, the detection surface of the road surface sensor unit 11 can remain clean. The road surface sensor unit 11 can function properly even when not traveling on rough roads 52. Furthermore, the control unit 20 keeps the valve member 16 open when the engine 41 of the automobile 1 is stopped and the automobile 1 is not running, and then closes the valve member 16 when the engine 41 of the automobile 1 starts and the automobile 1 is ready to run. This allows the drain tank 14 to be empty while the automobile 1 is not running and the engine 41 is stopped. This prevents drain water from freezing in the drain tank 14. It is considered that if the valve member 16 is kept open in this manner, the detection surface of the road surface sensor unit 11 will be washed by a large amount of drain water, and water droplets will likely remain on the detection surface of the road surface sensor unit 11. However, since the automobile 1 is not moving with the engine 41 stopped, the remaining water droplets on the detection surface of the road surface sensor unit 11 will not be a problem.

[0069] In this embodiment, the drain tank 14 and the road surface sensor unit 11 are provided in the engine compartment 40, which is the same as the heat source of the automobile 1. This makes it difficult for drain water to freeze in the drain tank 14. Also, water droplets adhering to the detection surface of the road surface sensor unit 11 do not freeze immediately. Eventually, no water droplets will remain on the detection surface of the road surface sensor unit 11.

[0070] In this embodiment, when the control unit 20 determines that the automobile 1 will pass through a puddle, it opens the valve member 16 for a certain period of time in synchronization with the timing at which the front wheels 43 of the automobile 1 pass through the puddle 53, and causes a curtain-like water flow to wash away the detection surface of the road surface sensor unit 11. This makes it difficult for dirt to remain on the detection surface of the road surface sensor unit 11 in the first place.

[0071] The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes are possible within the scope of the gist of the invention.

[0072] In the above-described embodiment, the drain water from the drain tank 14 is drained by gravity. Alternatively, for example, the drain water from the drain tank 14 may be discharged from the drain tank 14 under pressure using a pump or the like. Pressurization using a pump or the like is effective when, for example, the vertical positions of the air conditioner 12 and the drain tank 14 are different from those shown in FIG. 2 and the air conditioner 12 is positioned lower.

[0073] In the embodiment described above, the drain nozzle 15 provided in the drain tank 14 serves as a drain outlet for drain water. Alternatively, for example, a hose may be connected to the drain tank 14, with the tip of the hose serving as a drain outlet for drain water.

[0074] In the above-described embodiment, the drain outlet discharges the drain water from the drain tank 14 in a curtain-like manner to the front side of the detection surface of the road surface sensor unit 11. Alternatively, for example, the drain outlet may spray the drain water from the drain tank 14 directly onto the detection surface of the road surface sensor unit 11, or may scatter the water over a wide area by changing the direction or angle during distribution. In these cases, the drain water discharged from the drain outlet may be sprayed directly onto the detection surface of the road surface sensor unit 11. In contrast, in this embodiment, the drain water in the drain tank 14 is basically drained to the front side of the detection surface of the road surface sensor unit 11, and is not sprayed directly onto the detection surface of the road surface sensor unit 11. In this case, the drain water discharged from the drain outlet hits the detection surface of the road surface sensor unit 11 within the range considered necessary for cleaning the detection surface of the road surface sensor unit 11. The detection surface of the road surface sensor unit 11 is not wetted more than necessary. Even if a large amount of drain water more than necessary for cleaning accumulates in the drain tank 14, it is possible to prevent the detection surface of the road surface sensor unit 11 from being wetted more than necessary.

[0075] In the above-described embodiment, the control unit 20 discharges the drain water at limited timings from step ST9 to step ST11, from step ST15 to step ST2, and from step ST25 to step ST27. The control unit 20 may also open the valve member 16 at other times to drain the drain water from the drain tank 14. For example, when the drain water accumulated in the drain tank 14 is full or exceeds the amount required for cleaning, the control unit 20 may open the valve member 16 to drain the drain water from the drain tank 14. In this case, the control unit 20 may open the valve member 16 to drain the drain water from the drain tank 14 while the automobile 1 is stopped. This prevents excess drain water from hitting the detection surface of the road surface sensor unit 11. The detection surface of the road surface sensor unit 11 will not get wet unintentionally, which will reduce the detection performance. [Explanation of symbols]

[0076] 1...Automobile (vehicle), 10...Cleaning device, 11...Road surface sensor unit, 12...Air conditioning device, 13...Drainage duct, 14...Drainage tank, 15...Drainage nozzle, 16...Valve member, 17...Air conditioning duct, 20...Control unit, 21...External camera (road surface detection member), 22...Vehicle speed sensor, 23...Ignition switch, 24...Timer, 31...Cylindrical member, 32...Irradiation member, 33...Measuring member, 34...Detection surface member, 40...Engine compartment, 41...Engine, 42...Radiator, 43...Front wheel, 51...Paved road, 52...Rough road

Claims

1. a road surface sensor unit provided on a bottom of the vehicle body forward of the front wheels of the vehicle and facing the road surface; a drainage tank for storing drain water of the air conditioning device of the vehicle; a drain outlet provided forward of the detection surface of the road surface sensor unit in the vehicle travel direction, for discharging drain water from the drain tank; a valve member for discharging or stopping the drain water from the drain outlet; a control unit that controls the opening and closing of the valve member; a road surface detection member that detects or senses the road surface on which the vehicle is traveling; a vehicle speed sensor that detects or senses the speed of the vehicle; and The control unit the valve member is kept closed while the vehicle is in operation, and the valve member is opened for a certain period of time when a vehicle speed equal to or greater than a predetermined value is detected based on detection by the road surface detection member and detection by the vehicle speed sensor after the vehicle has traveled on a rough road; A cleaning device for vehicle road surface sensor units.

2. the road surface sensor unit is cylindrical and disposed so as to slope downwardly forward in the longitudinal direction of the vehicle; At the upper end of the vehicle in the upper direction, a near-infrared laser beam irradiation member; a measuring member for measuring the reflected light of the near-infrared laser light from a road surface; is established, a detection surface member that configures a detection surface of the road surface sensor unit is provided at a lower end of the road surface sensor unit; 2. The cleaning device for a road surface sensor unit for a vehicle according to claim 1.

3. an exhaust port of an air conditioning device of the vehicle provided on the front side of the vehicle relative to the drain outlet; a switch that is operated to switch the vehicle between a running state and a non-running state; and The control unit When the vehicle is changed from a running state to a non-running state by operating the switch, an air conditioning device of the vehicle is operated to exhaust conditioned air from the exhaust port, and the valve member is opened; maintaining the valve member in an open state when the vehicle is not moving; 3. The cleaning device for a road surface sensor unit for a vehicle according to claim 1 or 2.

4. The drain tank is located in the same compartment as the vehicle's heat source.

4. The cleaning device for a road surface sensor unit for a vehicle according to claim 3.

5. the road surface detection member senses or detects puddles on the road surface; The control unit when it is determined that the vehicle will pass through a puddle based on the detection or sensing of the road surface detection member, opening the valve member for a predetermined time in accordance with the timing when a front wheel of the vehicle passes through the puddle; 5. The cleaning device for a road surface sensor unit for a vehicle according to claim 4.

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