JP2011128879A - Vehicle-mounted apparatus for estimating weather condition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle-mounted apparatus for estimating a weather condition that estimates a futrure's weather condition in which a vehicle may be put. <P>SOLUTION: The estimation apparatus includes: an irradiation means that irradiates an oncoming vehicle that goes by an own vehicle with light; a light receiving means that receives a reflected light from the irradiation means. The estimation apparatus determines the existence of the oncoming vehicle, and whether a droplet is attached to the oncoming vehicle when the existence of the oncoming vehicle is confirmed based on a light receiving pattern of the reflected light received by the receiving means. The estimation apparatus estimates the weather condition in a travelling direction of the own vehicle based on the determined result. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an in-vehicle weather condition estimation apparatus, and more particularly to a weather condition estimation apparatus that is mounted on a vehicle and is suitable for estimating a weather condition in a traveling direction of the host vehicle (for example, whether there is rainfall or freezing on a road surface).

  2. Description of the Related Art Conventionally, an in-vehicle weather situation estimation device that includes a light projecting unit and a light receiving unit is known (see, for example, Patent Document 1). In this apparatus, the light projecting unit and the light receiving unit are embedded in the instrument panel of the vehicle. The light projecting unit projects pulsed light toward the front of the vehicle through the windshield, and the light receiving unit receives light from the light projecting unit reflected by the windshield. When raindrops adhere to the windshield, the amount of light from the light projecting unit that is reflected by the windshield and enters the light receiving unit is reduced as compared with the normal time. Therefore, according to said apparatus, the raindrop adhering to a windshield can be detected.

JP 2003-109184 A

  However, since the apparatus described in Patent Document 1 detects raindrops adhering to the windshield of the vehicle, it can detect the weather situation where the vehicle is actually placed, but the future where the vehicle will be placed in the future. It is not possible to estimate the weather conditions.

  The present invention has been made in view of the above-described points, and an object thereof is to provide an in-vehicle weather condition estimation device that can estimate a future weather condition that a vehicle will be placed in the future.

  The object is to irradiate light toward an oncoming vehicle passing by the own vehicle, light receiving means for receiving reflected light of light emitted by the irradiating means, and the reflected light received by the light receiving means. A water droplet adhesion determining means for determining whether or not water droplets adhere to the oncoming vehicle, and a weather condition for estimating a weather condition in the traveling direction of the host vehicle based on the determination result of the water droplet adhesion determining means And an in-vehicle meteorological situation estimation device including the estimation means.

  In the invention of this aspect, light is emitted from the irradiation means of the vehicle toward the oncoming vehicle passing the own vehicle, and reflected light of the light emitted toward the oncoming vehicle is received by the light receiving means. Then, based on the reflected light received by the light receiving means, it is determined whether or not water droplets are attached to the oncoming vehicle. If water droplets are attached to the oncoming vehicle, the amount of light from the light projecting unit that is reflected by the oncoming vehicle and received by the light receiving means is reduced as compared with the normal time. In the present invention, the weather condition in the traveling direction of the host vehicle is estimated based on the determination result of the water droplet adhesion in the oncoming vehicle. When water droplets are attached to the oncoming vehicle, it may be raining or snowing in the traveling direction of the host vehicle. Therefore, according to the present invention, it is possible to estimate a future weather situation that the host vehicle will be placed in the future.

  In the above-described on-vehicle weather condition estimation device, the water droplet adhesion determination means is based on the presence or absence of the oncoming vehicle and the oncoming vehicle based on the light receiving pattern of the reflected light received by the light receiving means. It may be determined whether or not water droplets adhere to the oncoming vehicle.

  The on-vehicle weather condition estimation apparatus further includes an outside air temperature detection unit that detects an outside air temperature, and the weather condition estimation unit is based on a determination result of the water droplet adhesion determination unit and a detection result of the outside air temperature detection unit. Thus, it may be estimated whether the road surface in the traveling direction of the host vehicle is frozen or wet.

  According to the present invention, it is possible to estimate a future weather situation where the vehicle will be placed in the future.

It is a block diagram of the vehicle-mounted weather condition estimation apparatus which is one Example of this invention. It is a figure for demonstrating the method of estimating a weather condition with the vehicle-mounted weather condition estimation apparatus of a present Example. It is a figure for demonstrating the method to discriminate | determine the presence or absence of the water droplet adhesion to an oncoming vehicle in the vehicle-mounted weather condition estimation apparatus of a present Example. It is a flowchart of an example of the control routine performed in the vehicle-mounted weather condition estimation apparatus of a present Example.

  Hereinafter, specific embodiments of an in-vehicle weather condition estimation apparatus according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration diagram of an in-vehicle weather condition estimation apparatus 10 according to an embodiment of the present invention. Moreover, FIG. 2 shows the figure for demonstrating the method of estimating a weather condition with the vehicle-mounted weather condition estimation apparatus 10 of a present Example. The in-vehicle meteorological situation estimation apparatus 10 of this embodiment is mounted on a vehicle, and can autonomously determine the future weather situation where a traveling vehicle will be placed in the future without obtaining external information from a weather satellite or the like. It is a device that estimates.

  As shown in FIG. 1, the in-vehicle weather condition estimation apparatus 10 includes an electronic control unit (hereinafter referred to as ECU) 12 mainly composed of a microcomputer. An optical transmission / reception sensor 14 is connected to the ECU 12. The light transmission / reception sensor 14 is disposed on the side of the vehicle body (more specifically, the side of the vehicle that passes by the oncoming vehicle; for example, the vehicle door or fender on the right side of the vehicle in Japan). This is a sensor capable of transmitting light toward (lateral direction) and receiving light from the vehicle width direction.

  The light transmission / reception sensor 14 includes a light emitting unit 16 that emits light and a light receiving unit 18 that receives light. Each of the light emitting unit 16 and the light receiving unit 18 is electrically connected to the ECU 12. The ECU 12 determines that the predetermined condition is satisfied (for example, when the ignition switch of the host vehicle is on and the wiper of the host vehicle is not operating; the predetermined condition is that the wiper is not operating). Since the relationship between the operation of the wiper = rainfall and snowfall can be established, there is a possibility that water droplets are attached to the lens surface of the light transmission / reception sensor 14, and the light transmission / reception sensor 14 cannot appropriately transmit / receive light. In order to irradiate the light from the light emitting unit 16, an operation command is issued to the light emitting unit 16, and when the predetermined condition is not satisfied, the irradiation of the light from the light emitting unit 16 is stopped. A non-operation command is issued to the light emitting unit 16 as much as possible.

  When the light emitting unit 16 receives an operation command from the ECU 12, the light emitting unit 16 emits light in a substantially horizontal direction toward the outside of the vehicle body. More specifically, light is irradiated toward the height position where the metal body is sandwiched between the front and rear rubber tires in the entire body side surface of the vehicle (that is, the oncoming vehicle passing the host vehicle) (FIG. 2). (See (B)). The light irradiation of the light emitting unit 16 is performed so as to be distinguishable from sunlight and disturbance light (in the present embodiment, intensity modulation is performed). Further, the light irradiation of the light emitting unit 16 is continued until the predetermined condition is not satisfied.

  The light receiving unit 18 has a resonance circuit that resonates at a frequency of the intensity amplitude of the light emitted from the light emitting unit 16. The light receiving unit 18 can extract only the frequency component of the intensity amplitude of the light while the light is emitted from the light emitting unit 16, and only the reflected light of the light emitted from the light emitting unit 16 is extracted. It is possible to receive light. The reception signal received by the light receiving unit 18 is supplied to the ECU 12. Based on the signal from the light receiving unit 18, the ECU 12 can determine whether the reflected light of the light from the light emitting unit 16 is received by the light receiving unit 18 and recognize the light reception pattern.

  An external air temperature sensor 20 is also connected to the ECU 12. The outside air temperature sensor 20 is a sensor that is disposed on the vehicle body and outputs a signal corresponding to the outside air temperature. The output of the outside air temperature sensor 20 is supplied to the ECU 12. The ECU 12 detects the temperature outside the vehicle (outside temperature) based on the output signal of the outside temperature sensor 20.

  Next, with reference to FIG.3 and FIG.4, operation | movement of the vehicle-mounted weather condition estimation apparatus 10 of a present Example is demonstrated. FIG. 3 is a diagram for explaining a method of determining whether or not water droplets adhere to the oncoming vehicle passing each other in the in-vehicle weather condition estimation apparatus 10 of the present embodiment. FIG. 4 shows a flowchart of an example of a control routine executed in the in-vehicle weather condition estimation apparatus 10 of the present embodiment.

  By the way, if there is no rain or snow on the road where the vehicle will be traveling in the future, water droplets will not adhere to the body of the vehicle that has passed through the road, while rain or When it is snowing, water droplets adhere to the body of the vehicle that has passed through the road. In this regard, if it is possible to detect the presence or absence of water droplets on the oncoming vehicle when the oncoming vehicle that may have passed the road on which the own vehicle will travel and the own vehicle pass each other, It is possible to estimate the future weather conditions that the vehicle will be placed in the future. In addition, in estimating the future weather situation that the host vehicle will be placed in the future, it is possible to increase the reliability of the estimation as the number of oncoming vehicles for which the presence or absence of water droplets is detected increases. Become.

  In the present embodiment, the light emitted from the light emitting part 16 of the light transmission / reception sensor 14 of the own vehicle is a rubber tire having a metal body in the front and rear of the oncoming vehicle that passes the own vehicle as described above. It is irradiated toward the height position sandwiched between. For this reason, the light emitted from the light emitting unit 16 of the own vehicle per oncoming vehicle passing the own vehicle is not reflected in the front and rear space portions of the oncoming vehicle, and the metal body portion on the side surface of the oncoming vehicle body Is reflected at two locations before and after the tire is present, so that the light receiving portion 18 is relatively reflected by the light reflected from the light emitting portion 16 reflected by the metal body portion on the side surface of the oncoming vehicle. While the light is received with a high intensity, the reflected light of the light from the light emitting part 16 reflected by the front and rear space portions of the oncoming vehicle and the tire portion of the oncoming vehicle is received with a relatively low intensity or not received at all. Become.

  In this case, as a light reception pattern in the light receiving unit 18, in order from the front to the rear for one oncoming vehicle, no signal or a small signal (a space portion in front of the oncoming vehicle) → a high signal (the metal body of the oncoming vehicle) The front part of the front wheel tire) → No signal or low intensity signal (front wheel tire part of the oncoming car) → High intensity signal (part between the front and rear tires of the metal body of the oncoming car) → None Signal or low intensity signal (rear wheel tire part of oncoming vehicle) → High intensity signal (rear part of rear wheel tire of metal body of oncoming car) → No signal or low intensity signal (space behind oncoming car) Part) is obtained for each predetermined section (see FIG. 3).

  When water droplets are not attached to the body of an oncoming vehicle that passes by the host vehicle, the light emitted from the light emitting part 16 of the own vehicle is reflected in a substantially uniform direction by the metal body portion on the side of the body of the oncoming vehicle. As the light receiving pattern received by the light receiving portion 18, a substantially uniform large intensity is obtained between the relatively small intensities at two front and rear positions corresponding to the tire portion. On the other hand, when water droplets are attached to the body of an oncoming vehicle passing by the host vehicle, the light irradiated from the light emitting part 16 of the host vehicle is irregularly reflected by the attached water droplets at the metal body portion on the side of the oncoming vehicle body Therefore, as the light receiving pattern received by the light receiving unit 18, a relatively small or zero intensity is obtained in some places with the attached water droplets between two relatively small intensities corresponding to the tire portion.

  Therefore, in the situation where light whose intensity is amplitude-modulated is emitted from the light emitting part 16 of the own vehicle, if it is determined whether there is light of relatively small intensity at two places before and after the tire portion of the oncoming vehicle, If there is an oncoming vehicle as a result of the determination, the presence or absence of the oncoming vehicle can be determined. Further, the light receiving section is relatively small or zero during the relatively strong light receiving section between the two relatively small intensities corresponding to the tire portion. It is possible to determine whether or not water droplets are attached to the body of the oncoming vehicle by determining the presence / absence of light of the above intensity.

  In the present embodiment, when the predetermined condition is satisfied as described above, the ECU 12 issues an operation command to the light emitting unit 16 to emit light from the light emitting unit 16 (step 100). In this case, the light whose intensity is amplitude-modulated in the substantially horizontal direction is emitted from the light emitting unit 16 toward the outside of the vehicle body. While receiving light from the light emitting unit 16, the light receiving unit 18 extracts only the frequency component of the intensity amplitude of the light (step 102).

  The ECU 12 determines whether or not the reflected light of the light from the light emitting unit 16 is received based on the signal from the light receiving unit 18 while irradiating the light from the light emitting unit 16, and recognizes the light receiving pattern. (Step 104). Then, as a result of the recognition of the light receiving pattern, in order from the front to the rear for one oncoming vehicle, no signal or low intensity signal → high intensity signal → no signal or low intensity signal → high intensity signal → no signal or Signal with low intensity → Signal with high intensity → No signal or signal with low intensity can be obtained, that is, there is a section where a signal with high intensity is sandwiched by no signal or a signal with low intensity, and this section is When formed at each location, it is determined that there is an oncoming vehicle that passes by the host vehicle.

  Further, in a situation where the ECU 12 determines that an oncoming vehicle exists, the ECU 12 is further provided at one or more preferably two light receiving sections of a high-intensity signal sandwiched between no-signals or low-intensity signals appearing at two front and rear positions. It is determined whether or not a signal having a low intensity or zero is included at a location or more, and it is determined whether or not water droplets are attached to the body of the oncoming vehicle (step 106).

  Note that a threshold value for determining the strength of the received signal at the light receiving unit 18 by the ECU 12 (specifically, a threshold value for determining whether the strength is low or whether the strength is high) is determined. (Threshold for determining whether the intensity is zero or not) may be determined experimentally in advance, or after the light receiving unit 18 is installed and mounted in the vehicle. Alternatively, it may be set to an average value of the intensity of the received signal obtained every time it passes the oncoming vehicle. Further, the processing of step 106, that is, whether or not water droplets adhere to the oncoming vehicle is determined for each of a plurality of oncoming vehicles that pass by the own vehicle, and the same determination result is obtained continuously for a predetermined number of vehicles. In such a case, it is sufficient if the subsequent processing is executed.

  If the ECU 12 determines that no water droplets are attached to the body of the oncoming vehicle, the ECU 12 thereafter ends the process. On the other hand, when it is determined that water droplets are attached to the body of the oncoming vehicle, the outside air temperature is detected based on the output signal of the outside air temperature sensor 20 (step 108). When the outside air temperature is detected, the outside air temperature is referenced to estimate the weather situation where the host vehicle will be placed in the future (step 110). Since the ECU 12 stores the maximum value of the outside air temperature at which the road surface freezes (hereinafter referred to as the “freezing determination threshold value”), the estimation of the weather condition in the step 110 by the ECU 12 is based on the freezing determination threshold value. This is performed with reference to the relationship with the detected outside air temperature by the outside air temperature sensor 20. Specifically, the road surface in the traveling direction in which the vehicle will travel in the future is frozen because the detected outside air temperature is equal to or lower than the freezing determination threshold value, or the detected outside air temperature exceeds the freezing determination threshold value. Thus, it is estimated whether or not rainfall has occurred in the traveling direction in which the host vehicle will travel in the future.

  When the ECU 12 estimates the weather condition that the host vehicle will be placed in step 110, the ECU 12 provides the estimated weather condition to the driver who drives the host vehicle through a display or a speaker (step 112). In this case, the driver of the own vehicle can know the weather situation where the own vehicle will be placed in the future by displaying video on the display and outputting sound from the speaker, and can respond promptly to the future weather situation. it can.

  As described above, in the present embodiment, by using the light transmission / reception sensor 14 to irradiate the oncoming vehicle passing the own vehicle with predetermined light and receiving the reflected light, water droplets adhere to the oncoming vehicle. It is possible to determine whether or not the vehicle is traveling, and it is possible to estimate the weather condition in the traveling direction of the host vehicle based on the determination result. Therefore, according to the in-vehicle meteorological situation estimation apparatus 10 of the present embodiment, it is possible to estimate the future meteorological situation where the host vehicle will be placed in the future, and further estimate the future meteorological situation. It is possible to carry out autonomously only on the vehicle side without obtaining external information from the vehicle.

  Also, in this embodiment, the estimation of the future weather situation that the vehicle will be placed in the future is based on not only the presence or absence of water droplets on the oncoming vehicle but also the outside temperature to which the vehicle is exposed. As a future weather condition to be estimated, it is possible to estimate whether or not the road on which the host vehicle will travel will be frozen. For this reason, according to the in-vehicle weather condition estimation apparatus 10 of the present embodiment, it is possible to estimate separately the rainfall and road surface freezing on the road on which the host vehicle will travel in the future.

  Further, in this embodiment, the estimation of the future weather situation that the host vehicle will be placed in the future is not made using only the presence or absence of water droplets in one oncoming vehicle that passes the own vehicle, but a plurality of oncoming vehicles. It is possible to carry out comprehensively using the presence or absence of each water droplet attachment at. If only one oncoming vehicle is subject to weather condition estimation, the accuracy of estimating future weather conditions will be reduced using the presence or absence of water droplets on the oncoming vehicle, for example, if the vehicle passes by an oncoming vehicle immediately after washing. There is a risk. On the other hand, according to the configuration of the present embodiment, since a plurality of oncoming vehicles are targeted for weather condition estimation, it is possible to avoid a decrease in the estimation accuracy and increase the reliability of the estimation. Is possible.

  In the above embodiment, the ECU 12 is connected to the light emitting unit 16 of the light transmission / reception sensor 14 in the “irradiating unit” described in the claims, and the light receiving unit 18 in the “light receiving unit” described in the claims. 4 executes the process of step 106 in the routine shown in FIG. 4 and “the meteorology” described in the claim indicates that the ECU 12 executes the process of step 110. It corresponds to “situation estimation means”.

  By the way, in the above embodiment, the future weather condition that the vehicle will be placed in the future is estimated with reference to the outside temperature, and it is estimated whether the road surface is frozen in the traveling direction of the vehicle. Although the present invention is possible, the present invention is not limited to this, and it is also possible to estimate the future weather condition based on the presence or absence of water droplets on the oncoming vehicle without referring to the outside temperature, You may estimate only whether the rain of the advancing direction of the own vehicle has arisen.

  In the above-described embodiment, the light receiving pattern received by the light receiving unit 18 of the light transmission / reception sensor 14 is recognized. When this pattern recognition is performed, the own vehicle and the oncoming vehicle that can be detected using various sensors are recognized. The relative speed in the vehicle width direction, the relative distance in the vehicle width direction, the size of the oncoming vehicle, the vehicle type, and the like may be taken into consideration.

  In the above embodiment, the light transmission / reception sensor 14 is used to transmit and receive light to determine whether or not water droplets adhere to the oncoming vehicle that passes by the host vehicle. Even if the light is reflected by the oncoming vehicle, the reflected light may not be received by the light receiving unit 18, and it may be difficult to determine whether water droplets are attached to the oncoming vehicle. Therefore, at night, infrared light may be transmitted and received to determine the presence or absence of water droplets on the oncoming vehicle that passes by the host vehicle.

10 On-vehicle weather condition estimation device 12 Electronic control unit (ECU)
14 Light transmission / reception sensor 16 Light emitting part 18 Light receiving part 20 Outside air temperature sensor

Claims (3)

Irradiating means for irradiating light toward an oncoming vehicle passing by the own vehicle;
A light receiving means for receiving reflected light of the light irradiated by the irradiation means;
Based on the reflected light received by the light receiving means, water droplet adhesion determining means for determining whether or not water droplets adhere to the oncoming vehicle;
Weather condition estimation means for estimating the weather condition of the traveling direction of the host vehicle based on the determination result of the water droplet adhesion determination means;
An in-vehicle weather condition estimation apparatus comprising:   The water droplet adhesion determining means determines presence / absence of the oncoming vehicle and presence / absence of water droplet adhesion to the oncoming vehicle when the oncoming vehicle exists based on the light receiving pattern of the reflected light received by the light receiving means. The in-vehicle weather condition estimation apparatus according to claim 1. An outside air temperature detecting means for detecting the outside air temperature,
The weather condition estimation means estimates whether the road surface in the traveling direction of the host vehicle is frozen or wet based on the determination result of the water droplet adhesion determination means and the detection result of the outside air temperature detection means. The in-vehicle meteorological situation estimation apparatus according to claim 1 or 2.

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