JP2011194361A - Optical sensor fouling prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical sensor fouling prevention device capable of changing the flow rate of gas to generate in front of an optical sensor for preventing dirt according to the size of fouling matters.SOLUTION: The optical sensor fouling prevention device is constituted of: a gas generator 30 for generating a gas flow Sin in front of the optical sensor 10; a fouling matter size detector 10 for detecting the size of the fouling matter P flying to come in front of the optical sensor 10; and gas flow rate adjusters 20 and 30 for changing the flow rate of the gas flow Sby the gas generator 30 according to the size of the detected fouling matter P. When the size of the fouling matter P is large, the flow rate of the gas flow Sis increased so as to prevent the fouling matter P from adhering to the optical sensor 10.

Description

  The present invention relates to an optical sensor antifouling device for preventing fouling from adhering to a light receiving surface of an optical sensor.

  2. Description of the Related Art Conventionally, in vehicles and the like, those equipped with a radar device for detecting an object existing ahead in the traveling direction are known. The water droplet adhesion suppression device for vehicle object detection means described in Patent Document 1 below forms an air flow that flows in front of the detection unit of an optical sensor that is an object detection means, and prevents adhesion of raindrops to the optical sensor. It is preventing. This prevents the detection accuracy from deteriorating by preventing the optical sensor from being damaged by raindrops.

JP 2008-74299 A Japanese Utility Model Publication No. 62-112960 JP 2008-1326 A JP 2008-288720 A JP 2001-142139 A

  However, since the technique described in Patent Document 1 does not consider the size of the contaminated object flying toward the optical sensor, for example, when the size of the contaminated object is large, the optical sensor is prevented from being contaminated. For this reason, there is a possibility that the flow rate of the gas to be flowed may be insufficient, and adhesion of pollutants cannot be prevented.

  The present invention has been made to solve such a problem, and an optical sensor capable of changing the flow rate of a gas flow generated in front of the optical sensor in accordance with the size of the contaminated material. An object of the present invention is to provide an anti-fouling device.

  The present invention relates to an optical sensor antifouling device for preventing fouling from adhering to an optical sensor, a gas flow generating means for generating a gas flow in front of the optical sensor, and a fouling flying in front of the optical sensor. A pollutant size detecting means for detecting the size of the object, and a gas amount adjusting means for changing the flow rate of the gas flow by the gas flow generating means according to the size of the pollutant detected by the pollutant size detecting means; It is characterized by providing.

  Such an optical sensor antifouling device can detect the size of the fouling by the fouling size detection means, and change the gas flow rate by the gas flow generation means according to the size of the fouling detected. it can. As a result, by changing the gas flow rate according to the size of the fouling material flying toward the optical sensor, the flow direction of the fouling material can be changed, and the fouling material can adhere to the light receiving part of the optical sensor. Can be prevented. As a result, it is possible to prevent a decrease in detection accuracy that occurs due to the adhering contaminants, and it is possible to maintain the performance of the optical sensor. By increasing the amount of gas when the size of the pollutant is large, a sufficient amount of gas can be secured and the pollutant can be reliably removed.

  Here, it is preferable that the gas amount adjusting means increases the flow rate of the gas flow when the size of the pollutant is large compared to when the size of the pollutant is small. In this way, even if a large-sized pollutant flies to the optical sensor, the flow of the pollutant is changed so as to avoid the optical sensor by strengthening the gas flow, and the adhering of the pollutant P is prevented. be able to.

  According to the optical sensor antifouling device of the present invention, it is possible to detect the size of the fouling material flying to the optical sensor and change the gas amount according to the size of the fouling material, thereby preventing a shortage of gas amount. As a result, it is possible to prevent fouling from adhering to the optical sensor.

1 is a schematic configuration diagram of an optical sensor antifouling device according to a first embodiment of the present invention. It is a flowchart which shows the process in the optical sensor antifouling apparatus of FIG. It is a schematic block diagram of the optical sensor pollution prevention apparatus which concerns on 2nd Embodiment of this invention. It is a flowchart which shows the process in the optical sensor antifouling apparatus of FIG. It is a schematic block diagram of the optical sensor pollution prevention apparatus which concerns on 3rd Embodiment of this invention. It is a flowchart which shows the process in the optical sensor antifouling apparatus of FIG. It is a schematic block diagram of the optical sensor pollution prevention apparatus which concerns on 4th Embodiment of this invention. It is a flowchart which shows the process in the optical sensor antifouling apparatus of FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the description of the drawings, similar elements may be denoted by the same reference numerals, and redundant descriptions may be omitted.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of an optical sensor antifouling device according to a first embodiment of the present invention. The optical sensor contamination preventing apparatus 10 prevents, for example, the contamination of the optical sensor 10 mounted on the vehicle. Examples of the optical sensor 10 include a camera, millimeter wave radar, and laser radar for acquiring environmental information around the host vehicle. A camera that acquires environmental information around the host vehicle is provided, for example, in front of the host vehicle, and detects an object (another vehicle, a pedestrian, etc.) in front of the host vehicle. In addition, a guard 11 is provided on the front side of the optical sensor 10 in order to prevent the contaminant P from adhering to the optical sensor 10. The guard 11 can be constituted by, for example, a transparent plate that transmits light.

  The optical sensor antifouling device 1 according to the present embodiment includes a controller 20 that inputs a signal output from the optical sensor 10 and an air ejection mechanism 30 that generates an air flow in front of the optical sensor 10. . The controller 20 is electrically connected to the optical sensor 10 and the air ejection mechanism 30.

  The controller 20 includes a CPU that performs arithmetic processing, a ROM and a RAM that are storage units, an input signal circuit, an output communication circuit, a power supply circuit, and the like. The controller 20 receives the signal output from the optical sensor 10 and calculates information related to the object such as the size and position of the object. The controller 20 is configured to be able to exchange data with another ECU (electronic control unit) that controls the vehicle by being connected by a communication circuit such as a CAN (Control Area Network). Information about the object detected by the optical sensor 10 is output to other ECUs and used for vehicle control.

  The air ejection mechanism 30 includes an air pump 31 for increasing the pressure of the air, a flow rate control valve 32 for controlling the flow rate of the ejected air flow, and nozzles 33A and B for ejecting the air flow. These air pump 31, flow control valve 32, and nozzles 33A and 33B are connected by piping. The air ejection mechanism 30 is for forming an air flow on the front surface side of the optical sensor 10 and preventing adhesion of the pollutant P flying to the optical sensor 10. Examples of the pollutant P include dust, dust, raindrops, and mud. The pollutant P adheres to the optical sensor 10 and may cause a decrease in sensor performance. The air ejection mechanism 30 corresponds to the gas flow generation means of the present invention that generates an air flow in front of the optical sensor 10.

The air ejection mechanism 30 includes a first nozzle 33A and a second nozzle 33B. The first nozzle 33 </ b> _A forms an air flow SA that is orthogonal to the traveling direction of the contaminant P approaching the optical sensor 10 immediately before the light receiving unit of the optical sensor 10. The second nozzle 33 </ b> _B forms an air flow SB that is inclined with respect to the traveling direction of the contaminant P approaching toward the optical sensor 10.

Here, the optical sensor antifouling apparatus 1 of this embodiment, fouling was detected the size of P, the detected contaminants P size airflow in accordance with the of S _A, S _B of the flow rate Q _A, Q _B can be changed. The optical sensor antifouling device 1 detects the size of the pollutant P by the optical sensor 10, and the controller 20 controls the flow rate control valve 32 according to the size of the pollutant P, from the nozzles 33 </ b> A, B. airflow _S a ejected, the flow rate _Q a of _{S B,} to vary the _{Q B.} The optical sensor 10 functions as a pollutant size detecting means of the present invention that detects the size of the pollutant P flying in front of the optical sensor 10. The controller 20 and the flow rate control valve 32 function as gas amount adjusting means for changing the flow rate of the gas flow according to the size of the pollutant P.

The controller 20 calculates the size of the pollutant P based on the signal from the optical sensor 10. For example, the controller 20 calculates the area of the object P in front view. The controller 20 transmits a command signal to the flow control valve 32 to adjust the valve opening degree of the flow control valve 32. If contaminants P is large, as compared with the case contaminants P is small, the air flow _S A, the flow rate _Q A of _{S B,} to increase the _{Q B.} The flow control valve 32 may be provided for each of the nozzles 33A and 33B, or may be common to both the nozzles 33A and 33B. Only one of the air flows from the nozzles 33A and 33B may be changed, or both of the flow rates may be changed.

Next, the operation of the optical sensor antifouling device 1 will be described with reference to the flowchart of FIG. Here, a case where only the flow rate Q _B of the air flow S _B formed by the second nozzle 33B is controlled will be described. First, the controller 20 inputs a signal output from the optical sensor 10 (step S1). Next, the controller 20 calculates the size of the contaminant P flying toward the optical sensor 10 based on the signal output from the optical sensor 10 (step S2).

Subsequently, the controller 20 refers to the data stored in the storage unit to determine the flow rate control of air flow S _B (step S3). The controller 20 is in proportion to the size of the contaminants P determines a control amount so as to increase the flow rate of the air flow S _B. In addition, the case where the magnitude | size of the pollutant P and the flow volume of an airflow are not directly proportional may be sufficient.

Next, the controller 20 transmits a command signal to the flow control valve 23 to control the valve opening so that the determined flow rate is obtained. Here, the flow rate Q _A of the air flow S _A by the first nozzle 33A is made constant, and the flow rate Q _B of the air flow S _B by the second nozzle 33B is changed. By strongly airflow S _B jetted from the second nozzle 33B, blow off contaminants P, and prevents contamination of the optical sensor 10 by contaminants P.

According to such an optical sensor antifouling device 1, the size of the pollutant P is detected by the optical sensor 10, and the air flow S by the air ejection mechanism 30 is detected according to the detected size of the pollutant P. it is possible to change the flow rate Q _B of the _B. Thus, depending on the size of the contaminants P to fly toward the optical sensor 10, by adjusting the flow rate Q _B of the air flow S _B, to change the direction of travel of contaminants P, fouling matters P Adhering to the light receiving part (guard 11) of the optical sensor 10 is prevented. As a result, the optical sensor 10 can be prevented from being soiled, the detection accuracy of the optical sensor 10 can be prevented from being lowered, and the performance of the optical sensor 10 can be maintained. By increasing the flow rate of the gas flow (air curtain) when the size of the pollutant P is large, a sufficient flow rate can be secured and the pollutant P can be reliably removed.

[Second Embodiment]
FIG. 3 is a schematic configuration diagram of an optical sensor antifouling device according to the second embodiment of the present invention. The optical sensor antifouling device 1B according to the second embodiment shown in FIG. 3 is different from the optical sensor antifouling device 1 of the first embodiment in that a wiper operation detector 41 that detects the operating state of the wiper, and The wheel speed sensor 42 for detecting the vehicle speed of the host vehicle is provided. The wiper operation detector 41 and the wheel speed sensor 42 are electrically connected to the controller 20.

The optical sensor antifouling device 1B is configured to detect the wiper operating condition and the vehicle speed, and to change the flow rate of the air flow according to the wiper operating condition and the vehicle speed. Optical sensor antifouling apparatus 1B according to the size of the contaminants P, with changing the flow rate Q _B of the air flow S _B ejected from the second nozzle 33B, in accordance with the operating condition and vehicle speed of the wiper The flow rate Q _A of the air flow S _A ejected from the first nozzle 33A is changed.

The wiper operation detector 41 detects a wiper switch ON / OFF signal and transmits a wiper signal indicating the operation status of the wiper to the controller 20. The controller 20 determines whether or not the wiper is operating based on the wiper signal output from the wiper operation detector 41. In general, when it is raining, the optical sensor 10 tends to be easily contaminated by the pollutant P such as raindrops and mud. Controller 20, when the wiper is operating, it is determined that the optical sensor 10 is easily soiled, and controls so as to increase the flow rate Q _B of the air flow S _B. On the other hand, when the wiper is not operating, it is determined that the optical sensor 10 is not easily soiled, and control is performed so as to decrease the flow rate Q _B of the air flow S _B. Instead of a signal from the wiper operation detector 41, a signal from a raindrop sensor that senses raindrops is received, and it is determined whether the optical sensor 10 is in a state of being easily contaminated. May be controlled. Moreover, it is good also as a structure which estimates the rainfall based on the signal from a raindrop detection sensor, and changes the flow volume of an airflow according to the grade of the intensity of rain.

The wheel speed sensor 42 detects the host vehicle speed and transmits a vehicle speed signal indicating the host vehicle speed to the controller 20. The controller 20 determines the vehicle speed based on the vehicle speed signal output from the wheel speed sensor 42. In general, when traveling at a high speed, the optical sensor 10 tends to be easily contaminated by the flying contaminant P. Controller 20, when the vehicle speed is high, as compared with the case that the own vehicle is slow, controlled so as to increase the flow rate Q _B of the air flow S _B.

Next, the operation of the optical sensor antifouling device 1B will be described. First, the controller 20, like the optical sensor antifouling apparatus 1 of the first embodiment, depending on the size of the contaminant P performs the processing shown in FIG. 2, controlling the flow rate Q _B of the air flow S _B .

Further, the optical sensor antifouling device 1B performs the process shown in FIG. The controller 20 inputs the vehicle speed signal output from the wheel speed sensor 42 (step S11). Subsequently, the controller 20 refers to the data stored in the storage unit to determine the flow rate control of air flow S _A (step S12). The controller 20 determines the control amount so as to increase the flow rate Q _A of the air flow S _A in proportion to the host vehicle speed. In addition, the case where the own vehicle speed and the flow volume of an airflow are not directly proportional may be sufficient.

  Next, the controller 20 inputs the wiper signal output from the wiper operation detector 41 (step S13). Subsequently, the controller 20 determines whether or not the wiper is operating based on the wiper signal output from the wiper operation detector 41 (step S14). If the wiper signal is ON, the controller 20 determines that the wiper is operating and proceeds to step S15. On the other hand, if the wiper signal is OFF, the controller 20 determines that the wiper is not operating and proceeds to step S16.

In step S15, the controller 20, the correction coefficient K for correcting the control amount of the air flow _{S A,} set the "correction factor K = _{K 1",} the flow proceeds to step S17. In step S16, the controller 20 sets “correction coefficient K = K ₂ ” in the correction coefficient K, and proceeds to step S17. For example, the correction coefficient K is set as K ₁ > K ₂ . Nachi Suwa, when the wiper is in the operating state is corrected so that the flow rate Q _A of the air flow S _A is increased, when the wiper is not in operating state, decreases the flow rate Q _A of the air flow S _A To be corrected.

In step S17, the controller 20 calculates a flow rate Q _A (= Q _A1 × K) that is a control target. Next, the controller 20 sends a command signal to the flow control valve 23 controls the valve opening degree so that the determined flow rate Q _A, changing the flow rate Q _A of the air flow S _A according to the first nozzle 33A To do.

According to such an optical sensor antifouling device 1B, the size of the pollutant P is detected by the optical sensor 10 and ejected from the second nozzle 33B according to the detected size of the pollutant P. it is possible to change the flow rate _{Q B} of the air flow _{S B.} Thus, depending on the size of the contaminants P to fly toward the optical sensor 10, by changing the flow rate Q _B of the air flow S _B, to change the direction of travel of contaminants P, fouling matters P Adhering to the light receiving portion of the optical sensor 10 is prevented. As a result, the optical sensor 10 can be prevented from being soiled, the detection accuracy of the optical sensor 10 can be prevented from being lowered, and the performance of the optical sensor 10 can be maintained. By increasing the flow rate of the gas flow when the size of the pollutant P is large, a sufficient flow rate can be secured and the pollutant P can be reliably removed.

Further, according to the optical sensor antifouling device 1B, the vehicle speed is detected by the wheel speed sensor 42, and the flow rate Q _A of the air flow S _A ejected from the first nozzle 33A is determined according to the detected vehicle speed. Can be changed. Accordingly, when the vehicle speed is high, as compared with the case slow, by increasing the flow rate Q _A of the air flow S _A, to ensure sufficient flow, can be removed reliably contaminants P. Further, when the vehicle speed is slow, as compared with the case fast, by decreasing the flow rate Q _A of the air flow S _A, while maintaining the antifouling effect, energy saving (fuel efficiency), compatibility between the noise reduction effect Can be achieved.

Further, according to the optical sensor antifouling device 1B, the wiper operation detector 41 detects the operation state of the wiper, and the flow rate Q of the air flow S _A ejected from the second nozzle 33B according to the operation state of the wiper. _A can be changed. Thereby, when the wiper is operating, by increasing the flow rate Q _A of the air flow S _A , a sufficient flow rate can be ensured and the pollutant P can be reliably removed. Further, when the wiper is not operating, by reducing the flow rate Q _A of the air flow S _A, while maintaining the antifouling effect, energy saving (fuel efficiency), it is possible to achieve both the noise reduction effect .

[Third Embodiment]
FIG. 5 is a schematic configuration diagram of an optical sensor antifouling device according to a third embodiment of the present invention. The optical sensor antifouling device 1C according to the third embodiment shown in FIG. 5 is different from the optical sensor antifouling device 1 of the first embodiment in that a washer mechanism 50 is provided, and an air ejection mechanism 30 is provided. The second nozzle 33B is not provided.

Air injection mechanism 30 of the optical sensor antifouling apparatus 1C, depending on the size of the contaminants P, there is a changeable configuration the flow rate Q _A of the air flow S _A ejected from the first nozzle 33A.

  Here, the optical sensor antifouling device 1C of the present embodiment can set ON / OFF of the washer mechanism 50 according to the input value from the optical sensor 10 in the activated state when the ignition switch is operated. It is made into the composition.

  The washer mechanism 50 includes a washer pump 51 for supplying a cleaning liquid and a washer nozzle 52 for injecting the cleaning liquid. The washer pump 51 operates according to the command signal output from the controller 20 and supplies the cleaning liquid to the washer nozzle 52. The washer nozzle 52 is provided on the front side of the optical sensor 10 and removes dirt adhering to the guard 11 by spraying the cleaning liquid onto the guard 11.

The controller 20 is electrically connected to the ignition switch 43. The controller 20 receives an ignition signal (hereinafter referred to as an “IG” signal) indicating that the ignition switch 43 is switched from the OFF state to the ON state. The controller 20 detects switching of the ignition switch 43 from the OFF state to the ON state based on the received IG signal. When the ignition switch 43 is switched to the ON state, the controller 20 stores the input value G from the optical sensor 10 in the storage unit. The controller 20, when the ignition switch 43 is switched to the ON state, the input value G ₁ from the optical sensor 10 in the previous startup, the input value G ₂ from the optical sensor 10 at the current startup Are compared, and the attenuation G ₃ (= G ₂ −G ₁ ) of the input value is calculated. The controller 20, based on the calculated attenuation G _3, controls the presence or absence of operation of the washer mechanism 50.

  Next, the operation of the optical sensor antifouling device 1C will be described with reference to the flowchart of FIG. The controller 20 inputs the signal output from the ignition switch 43 (step S21), and determines whether or not an IG signal indicating that the ignition switch 43 is switched from the OFF state to the ON state is received. When it is determined that the ignition switch 43 has been switched from the OFF state to the ON state, the process proceeds to step S23, and when it is not determined that the ignition switch 43 has been switched from the OFF state to the ON state, the process proceeds to step S24. .

In step S23, the controller 20 reads the input value G ₁ from the optical sensor 10 in the previous startup stored in the storage unit, the process proceeds to step S25. In step S24, the controller 20 stores the input value _{G 2} from the optical sensor 10 at the current startup in the storage unit, the process proceeds to step S25.

In step S < _b > 25, the controller 20 calculates the attenuation value G ₃ (= G ₂ −G ₁ ) of the signal output from the optical sensor 10.

In step S26, the controller 20, the attenuation value _{G 3} determines whether a predetermined larger criterion value _{G 4.} If the attenuation value G ₃ is determined to be larger than the determination reference value G ₄ are, the process proceeds to step S27, if the attenuation value G ₃ is not determined to be larger than the determination reference value G ₄ are, the process proceeds to step S28 .

  In step S27, the controller 20 turns on the operation of the washer mechanism 50. The controller 20 transmits a command signal, drives the washer pump 51, removes dirt adhering to the guard 11 of the optical sensor 10, and proceeds to step S28.

In step S28, air ejection mechanism drive control is executed. The controller 20 performs the same process as that shown in FIG. 2 and controls the flow rate Q _A of the air flow S _A according to the size of the contaminated material P.

According to such an optical sensor antifouling device 1C, the size of the pollutant P is detected by the optical sensor 10 and ejected from the first nozzle 33A according to the detected size of the pollutant P. it is possible to change the flow rate _{Q a} of the air flow _{S a.} Thus, depending on the size of the contaminants P to fly toward the optical sensor 10, by changing the flow rate Q _A of the air flow S _A, it changes the traveling direction of the contaminants P, fouling matters P Adhering to the light receiving portion of the optical sensor 10 is prevented. As a result, the optical sensor 10 can be prevented from being soiled, the detection accuracy of the optical sensor 10 can be prevented from being lowered, and the performance of the optical sensor 10 can be maintained. By increasing the flow rate of the gas flow when the size of the pollutant P is large, a sufficient flow rate can be secured and the pollutant P can be reliably removed.

Further, according to the optical sensor antifouling apparatus 1C, it is possible in accordance with the attenuation value G ₃ of the input value from the optical sensor 10, to determine the presence or absence of operation of the washer mechanism 50. Thereby, for example, when the optical sensor 10 becomes dirty while the vehicle is stopped, the performance of the optical sensor 10 can be recovered by operating the washer mechanism 50 to perform cleaning. Further, when the input value is not attenuated, by not performing the cleaning by the washer mechanism 50, it is possible to reduce the amount of the cleaning liquid used and to reduce the work frequency for replenishing the cleaning liquid. . Therefore, the troublesome maintenance work can be reduced while maintaining the antifouling effect. By optimizing the number of operations of the washer mechanism 50, fuel consumption can be improved.

[Fourth Embodiment]
FIG. 7 is a schematic configuration diagram of an optical sensor antifouling device according to a fourth embodiment of the present invention. The optical sensor antifouling device 1D according to the fourth embodiment shown in FIG. 7 is different from the optical sensor antifouling device 1 of the first embodiment in that it includes a guard rotation mechanism 61 and a guard cleaner 62. Is a point. The guard rotation mechanism 61 is electrically connected to the controller 20.

Air injection mechanism 30 of the optical sensor antifouling apparatus 1D, depending on the size of the contaminants P, there is a changeable configuration the flow rate Q _B of the air flow S _B ejected from the second nozzle 33B.

  Here, the optical sensor antifouling device 1D of the present embodiment turns on / off the guard rotation mechanism 61 according to the input value from the optical sensor 10 in the activated state when the ignition switch is operated. The configuration is configurable.

  The guard rotation mechanism 61 operates according to the command signal output from the controller 20 and rotates the guard 11. The guard 11 has a curved outer surface, for example, a C shape in plan view. The guard 11 is rotatable around a predetermined axis. Further, a pair of guard cleaners 62 for removing dirt on the surface of the guard 11 is provided on the front side of the guard 11. The guard cleaner 62 is disposed in close contact with the surface of the guard 11 and is configured to wipe off dirt on the surface of the guard 11. The guard 11 is rotated around a predetermined axis by the guard rotating mechanism 61, so that the dirt attached to the surface of the guard 11 is wiped off.

The controller 20 is electrically connected to the ignition switch 43. The controller 20 receives an ignition signal (hereinafter referred to as an “IG” signal) indicating that the ignition switch 43 is switched from the OFF state to the ON state. The controller 20 detects switching of the ignition switch 43 from the OFF state to the ON state based on the received IG signal. When the ignition switch 43 is switched to the ON state, the controller 20 stores the input value G from the optical sensor 10 in the storage unit. The controller 20, when the ignition switch 43 is switched to the ON state, the input value G ₁ from the optical sensor 10 in the previous startup, the input value G ₂ from the optical sensor 10 at the current startup Are compared, and the attenuation G ₃ (= G ₂ −G ₁ ) of the input value is calculated. The controller 20, based on the calculated attenuation G _3, controls the presence or absence of operation of the washer mechanism 50.

FIG. 8 is a flowchart showing processing in the optical sensor antifouling apparatus 1D. The flowchart shown in FIG. 8 is different from the flowchart shown in FIG. 6 in that step S37 is executed instead of step S27. In the optical sensor antifouling apparatus 1D, in step S26, if the attenuation value _{G 3} is determined to be larger than the determination reference value _{G 4,} the process proceeds to step S37.

  In step 37, the controller 20 activates the guard rotation mechanism 61 to remove the dirt from the guard 11. The controller 20 transmits a command signal to the guard rotation mechanism 61 and drives to rotate the guard 11 around a predetermined axis, and proceeds to step S28. As the guard 11 rotates, the guard cleaner 62 removes dirt adhered to the surface of the guard 11.

According to such an optical sensor antifouling device 1D, the optical sensor 10 detects the size of the pollutant P, and ejects from the second nozzle 33B according to the detected size of the pollutant P. it is possible to change the flow rate _{Q B} of the air flow _{S B.} Thus, depending on the size of the contaminants P to fly toward the optical sensor 10, by changing the flow rate Q _B of the air flow S _B, to change the direction of travel of contaminants P, fouling matters P Adhering to the light receiving portion of the optical sensor 10 is prevented. As a result, the optical sensor 10 can be prevented from being soiled, the detection accuracy of the optical sensor 10 can be prevented from being lowered, and the performance of the optical sensor 10 can be maintained. By increasing the flow rate of the gas flow when the size of the pollutant P is large, a sufficient flow rate can be secured and the pollutant P can be reliably removed.

Further, according to the optical sensor antifouling apparatus 1D, it can be in accordance with the attenuation value G ₃ of the input value from the optical sensor 10, to determine the presence or absence of operation of the guard turning mechanism 61. Thereby, for example, when the optical sensor 10 becomes dirty while the vehicle is stopped, the performance of the optical sensor 10 is recovered by operating the guard rotation mechanism 61 to remove the dirt of the guard 11. be able to. Further, when the attenuation of the input value is not recognized, the life of the guard cleaner 62 can be extended by not operating the guard rotation mechanism 61. Therefore, the troublesome maintenance work can be reduced while maintaining the antifouling effect. Fuel efficiency can be improved by optimizing the number of times of operation of the guard rotation mechanism 61.

  As mentioned above, although this invention was concretely demonstrated based on the embodiment, this invention is not limited to the said embodiment. In the above embodiment, the optical sensor antifouling device mounted on the vehicle is described. However, the optical sensor antifouling device may be mounted on another moving body to prevent the optical sensor from being contaminated. For example, the present invention may be applied not to a moving body but to prevent contamination of an optical sensor installed on a fixed structure, for example.

  Moreover, in the said embodiment, although the optical sensor antifouling apparatus 1 has generated the air flow, gas other than air may be sufficient as a gas flow.

  Moreover, in the said embodiment, although the magnitude | size of the pollutant P is detected using the optical sensor 10 which is the object of pollution prevention, the pollutant P is used using another sensor different from the optical sensor 10. May be detected.

DESCRIPTION OF SYMBOLS 1,1B, 1C, 1D ... Optical sensor antifouling device, 10 ... Optical sensor (fouling thing size detection means), 11 ... Guard, 20 ... Controller (gas amount adjustment means), 30 ... Air ejection mechanism (gas flow) Generating means), 31 ... air pump, 32 ... flow control valve, 33A ... first nozzle, 33B ... second nozzle, 41 ... wiper operation detector, 42 ... wheel speed sensor, 43 ... ignition switch, 50 ... washer mechanism ( Cleaning means), 51 ... washer pump, 52 ... washer nozzle, 61 ... guard rotating mechanism, 62 ... guard cleaner, P ... dirt, S _A , S _B ... air flow.

Claims (2)

In the optical sensor antifouling device for preventing the adhesion of fouling substances to the optical sensor,
Gas flow generating means for generating a gas flow in front of the optical sensor;
A pollutant size detecting means for detecting the size of the pollutant flying in front of the optical sensor;
An optical sensor antifouling device comprising gas amount adjusting means for changing the flow rate of the gas flow by the gas flow generating means according to the size of the fouling substance detected by the fouling substance size detecting means.   2. The optical sensor according to claim 1, wherein the gas amount adjusting unit increases the flow rate of the gas flow when the size of the pollutant is large compared to when the size of the pollutant is small. Antifouling device.

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