JPH1010240A - Snowfall sensor and snowfall meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the measurement accuracy of snowfall by projecting a body for leading the light from a projecting section to the outside of a housing from the housing and leading a backscattering light from the outside of the housing to a light receiving section through a light lead-in body. SOLUTION: Each of a light lead-out body 4 and a light lead-in body 5 comprises an optical fiber and a pair of light lead-out bodies 4 are projected in parallel from one side face of a housing 1 while a light lead-in body 5 is projected from between. A level difference of about 2mm is provided between the lead-in end face 5a of the light lead-in body 5 and the lead-out end face 4a of the light lead-out body 4 so that the lead-in end face 5a is set back. Light is emitted from a light emitting part comprising a light emitting element 2a in the housing 1 and backscattering light from snowfrake in the air under snowfall conditions is received at a light receiving section 3 comprising a light receiving element 3a. The projecting structure of the light lead-out body 4 and the light lead-in body 5 can suppress the effect on the streamline of the wind and the detection sensitivity of snowflake is enhanced thus enhancing the measurement accuracy of snowfall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a snowfall sensor and a snowfall intensity meter which are used for, for example, optical measurement of snowfall intensity and efficient operation control of snow removal equipment.

[0002]

2. Description of the Related Art FIG.
As shown in FIG. 8, a light emitting element 2a is provided in a rectangular box-shaped housing 1.
And a light receiving unit 3 having a light receiving element 3a. The light receiving unit 3 receives backscattered light from the snowflakes S in the air of light emitted from the light emitting unit 2 to the outside of the housing 1. A snowfall intensity meter having a signal processing unit that outputs a snowfall intensity signal based on a light reception signal from the snowfall sensor is known, and based on the snowfall intensity signal, For example, it is configured to perform operation control of the water spray type snow removal equipment and automatic measurement of the snowfall state.

[0003]

However, in the case of the above-mentioned conventional structure, the light projecting portion 2 and the light receiving portion 3 are housed in the housing 1 and are provided via a light transmitting outer wall portion formed on one side of the housing 1. And the backscattered light from the snowflakes S is detected by the light receiving portion via the light transmitting outer wall portion of the housing 1 so that the snowflakes descend substantially straight in a windless state. This has no effect on the light detection of the snowflakes. However, as shown in FIG. 8, when the wind blows, the stream R of the air flows around the housing 1 avoiding one side of the housing 1 and, as a result, However, the snowflakes S pass through the one side of the housing 1 together with the streamlines R, and the detection sensitivity of the snowflakes S may be reduced accordingly.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve such inconvenience, and among the present invention, the invention described in claim 1 is a light emitting unit having a light emitting element in a housing. And a light receiving unit having a light receiving element, and a light receiving unit that detects backscattered light from snowflakes in the air of light emitted from the light emitting unit to the outside of the housing. And a light guide for guiding the light emitted from the light projecting portion in the housing to the outside of the housing, and a light guide for guiding the backscattered light from outside the housing to the light receiving portion in the housing. It is a feature of the snowfall sensor.

According to a second aspect of the present invention, the light guide and the light guide are made of an optical fiber, and the third aspect of the present invention provides the light guide in the housing. 5. The apparatus according to claim 4, wherein two light guides are provided in parallel and said one light guide is provided between said two light guides in a parallel state.
The described invention is characterized in that the introduction end face of the one light introducing body is arranged to be retracted closer to the housing than the leading end faces of the two light extraction bodies.

[0006] The invention described in claim 5 is the above-described claim 1.
4. A snowfall intensity meter comprising: the snowfall sensor according to any one of (1) to (4); and a signal processing unit that outputs a snowfall intensity signal based on a light receiving signal from the snowfall sensor and a snow / rain discrimination signal from a temperature sensor.

[0007]

1 to 6 show an embodiment of the present invention. Reference numeral 1 denotes a housing which is made of synthetic resin into a rectangular box having a width of 40 mm, a depth of 30 mm and a height of 15 mm. Have been.

Reference numeral 2 denotes a light emitting portion, which has a light emitting element 2a housed in the housing 1, and in this case, a red light emitting diode having a resin lens is used.

Reference numeral 3 denotes a light receiving section, which has a light receiving element 3a housed in the housing 1, and in this case, a photodiode is used.

Reference numeral 4 denotes a light guide, and 5 denotes a light guide. The light guide 4 and the light guide 5 are composed of optical fibers having an outer diameter of 3 mm. Protective cylinder 4 made of aluminum pipe with 0.5mm thickness on the surface
b and 5b, both of which are protruded from one side of the housing 1. In this case, two light guides 4 are arranged in parallel on one side of the housing 1.
It protrudes about 1 mm in length and has two light guides 4.
4, one light introducing member 5 is protruded in a parallel state, and an introduction end face 5 a as an outer terminal surface of the one light introducing member 5.
Is a leading end 4 as an outer terminal surface of the two light leading bodies 4.
In this case, a step H of about 2 mm is retracted toward the housing 1 side from the surface a.

In this case, two light emitting elements 2a are arranged in the housing 1 in a parallel state, and the light emitting elements 2a are arranged in parallel.
The light receiving elements 3a are arranged between the light emitting elements 2a, the inner terminal surfaces of the light guides 4 are arranged to face the respective light emitting elements 2a, and the light receiving elements 3a are arranged.
The inside terminal surface of the light introducing body 5 is disposed to face the printed circuit board 6, the printed circuit board 6 is disposed in the housing 1, and a resistance as the heater body 7 is provided inside the housing 1. And the mounting case 9 is configured to be mounted on a wall surface, a pole, or the like.

Reference numeral 10 denotes an optical sensor unit, and 11 denotes a signal processing unit. The optical sensor unit 10 includes a timing generation circuit 12 having an oscillator, an LED drive circuit 13, a preamplifier circuit 1,
4, a reference voltage generating circuit 15, a comparator circuit 16, a signal processing circuit 17, and an output circuit 18.

The timing generating circuit 12 generates a reference oscillation output by charging / discharging a built-in capacitor with a constant current to generate an LED driving pulse and various timing pulses for digital signal processing. The light emitting diode as the light emitting element 2a is driven by the generated LED driving pulse, and the preamplifier circuit 14 converts the photocurrent of the on-chip type photodiode as the light receiving element 3a into a voltage, and uses an AC amplifier circuit for DC and low frequency. The dynamic range for disturbance light is expanded to enhance signal detection sensitivity, and the reference voltage generation circuit 15 further removes low-frequency disturbance light by C-coupling, removes the DC offset of the preamplifier section, and amplifies to the comparator level by the buffer amplifier. , Generates a comparator level signal, and A hysteresis function is added to the data circuit 16 to prevent chattering due to minute fluctuations in the input light. The signal processing circuit 17 is composed of a gate circuit and a digital integrator circuit. To prevent malfunction due to asynchronous disturbance light, and because synchronous disturbance light cannot be removed by the gate circuit, it is removed by the digital integration circuit at the subsequent stage. Also, the output circuit 18 buffers the output of the signal output circuit. The light receiving signal a as an output signal is output while suppressing the influence of disturbance light.

The signal processing section 11 includes a counter circuit 19 having a timer circuit, a comparator 20, a DA converter 21, a logic circuit 22, a temperature sensor 23 including a thermistor, a comparator 24, and an output circuit 25.
The counter circuit 19 outputs the snowfall intensity signal b by counting the light receiving signal a from the optical sensor unit 10 at regular intervals within a constant time, and detects the precipitation temperature by the temperature sensor 23. 0.3 ° C. or less is determined as snow and above is determined as rain, and snow and rain is determined. The snow / rain determination signal and the output signal from the comparator circuit 20 are input to the logic circuit 22, and the output circuit 25 is determined by ANDing both output signals. It is configured to output a snowfall signal c.

Thus, the snowfall intensity signal b and the snowfall signal c
Thereby, for example, efficient operation control of the snow removal equipment and automatic measurement of the snowfall state are performed.

Since this embodiment has the above configuration,
Light is emitted from the light projecting portion 2 having the light emitting element 2a housed in the housing 1, and in the snowfall state, the backscattered light from the snowflakes S in the air is received by the light receiving element 3a having the light receiving element 3a in the housing 1. The light is detected and detected by the unit 3. At this time, the light guide 4 and the light guide 5 are protruded from the housing 1, and the light guide 4 emits the light emitted from the light projecting unit 2 in the housing 1. Is guided out of the housing 1 and the light introducing body 5 guides the backscattered light from the outside of the housing 1 to the light receiving section 3 in the housing 1. Protrusions of the introduction body 5 can suppress the influence of the form of the housing 1 on the streamline R of the wind when the wind blows as shown in FIG. One side of housing 1 with R Can be suppressed through the avoiding, it can be able to enhance the detection sensitivity of snowflakes S to improve the measurement accuracy of the snowfall.

In this case, since the light guide 4 and the light guide 5 are made of optical fibers, the amount of light attenuation can be suppressed, and the detection sensitivity of the snowflakes S can be increased accordingly. Since two light guides 4 project from the housing 1 in a parallel state and one light guide 5 projects between the two light guides 4 in a parallel state, for example,
A light projecting unit 2 and a light receiving unit 3 each having a conventional structure shown in FIG.
As compared with the case where one light guide 4 and one light guide 5 are arranged in parallel, as shown in FIG. The sensitivity can be increased and the cost can be reduced. In this case, the introduction end face 5 of one light introducing body 5
Since the a is retracted arranged in the housing 1 side from the outlet end surface 4a of the two light outlet member 4, as shown in FIG. 6, it is possible to reduce the concave portion T ₁ of the sensing area T of the planar heart shape Accordingly, the sensing area T can be further expanded, and the detection sensitivity can be increased.

In this case, a snowfall intensity signal b based on the snowfall sensor shown in the above embodiment and a light receiving signal a from the snowfall sensor and a snow / rain discrimination signal from the temperature sensor 23 is used.
And a signal processing unit 11 that outputs a snowfall signal c, so that the snowfall intensity meter is configured, so that, for example, the operation control of the snow removal equipment and the automatic measurement of the snowfall state are performed with the effect of the snowfall sensor. Therefore, efficient operation control and highly accurate measurement can be performed.

Further, in this case, since the heater 7 is built in the housing 1, it is possible to suppress a snow accretion phenomenon in a bridging state between the light guide 4 and the light introducer 5, and accordingly, It is possible to satisfactorily extract light and introduce backscattered light.

It should be noted that the present invention is not limited to the above-described embodiment, but the types of the light emitting element 2a and the light receiving element 3a, the materials and forms of the light guide 4 and the light guide 5, the light sensor section 10 and The configuration and the like of the signal processing unit 11 are appropriately modified and designed.

[0021]

According to the present invention, as described above, in the invention of the snowfall sensor according to the first aspect, light is emitted from the light projecting portion having the light emitting element housed in the housing, and in the snowfall state, the light is emitted. The backscattered light from the snowflakes in the air is received and detected by a light receiving unit having a light receiving element in the housing. At this time, a light guide and a light guide are protruded from the housing, and the light guide is provided. Guides the light emitted from the light projecting portion in the housing to the outside of the housing, and the light introducing body guides the backscattered light from the outside of the housing to the light receiving portion in the housing. Since the light guide and the light guide are protruded from the housing, it is possible to suppress the influence of the shape of the housing on the streamline of the wind when the wind blows, and the snowflake and the streamline together with the streamline form the housing. Around the side of the surface, to pass to avoid can be suppressed, it is possible to increase the detection sensitivity of the snowflake, it is possible to improve the measurement accuracy of the snowfall.

Further, in the invention of the snowfall sensor according to claim 2, since the light guide and the light guide are made of optical fibers, the amount of light attenuation can be suppressed, and the detection sensitivity of snowflakes can be increased accordingly. According to the invention of the snowfall sensor according to claim 3, two light guides are protruded from the housing in a parallel state, and one light guide is arranged in parallel between the two light guides. Since it is protruding from the state, compared to the case where one light guide and one light guide are arranged in parallel,
The sensing area can be expanded, the detection sensitivity can be increased accordingly, and the cost can be reduced.
Further, in the invention of the snowfall sensor according to the fourth aspect, since the introduction end face of one light introduction body is disposed to be retracted closer to the housing than the exit end faces of the two light introduction bodies, the sensing area is reduced. It is possible to further enlarge the detection sensitivity.

According to a fifth aspect of the present invention, there is provided a snowfall intensity meter based on the snowfall sensor according to any one of the first to fourth aspects, a light receiving signal from the snowfall sensor, and a snow / rain discrimination signal from the temperature sensor. Since the signal processing unit that outputs the snowfall intensity signal is provided, efficient operation control and highly accurate measurement can be performed in the operation control of the snow removal equipment and the automatic measurement of the snowfall state.

As described above, the intended purpose can be sufficiently achieved.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of an embodiment of the present invention.

FIG. 2 is a partial plan sectional view of the embodiment of the present invention.

FIG. 3 is a partial side sectional view of the embodiment of the present invention.

FIG. 4 is a block circuit diagram of an embodiment of the present invention.

FIG. 5 is an explanatory plan view of the embodiment of the present invention.

FIG. 6 is an explanatory plan view of the embodiment of the present invention.

FIG. 7 is an explanatory plan view of a conventional structure.

FIG. 8 is an explanatory plan view of a conventional structure.

[Explanation of symbols]

 T Sensing area S Snowflake a Light reception signal b Snowfall intensity signal c Snowfall signal 1 Housing 2 Light emitting unit 2a Light emitting element 3 Light receiving unit 3a Light receiving element 4 Light guide 4a Terminal surface 5 Light introducing unit 5a Terminal surface 11 Signal processing unit 23 Temperature Sensor

[Procedure amendment]

[Submission date] June 26, 1996

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 4

[Correction method] Change

[Correction contents]

FIG. 4

[Procedure amendment]

[Submission date] July 25, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

Claims (5)

[Claims] 1. A housing in which a light emitting unit having a light emitting element and a light receiving unit having a light receiving element are housed in a housing, and light emitted from the light emitting unit to the outside of the housing is scattered by backscattered light from snowflakes in the air. In a snowfall sensor detected by a light receiving unit, a light guide that protrudes from the housing and guides light emitted from a light projecting unit in the housing to the outside of the housing and the backscattered light to a light receiving unit in the housing. Snowfall sensor comprising a light introducing member for guiding the light from outside the housing. 2. The snowfall sensor according to claim 1, wherein the light guide and the light guide comprise optical fibers. 3. A light-emitting device comprising: a plurality of light guides projecting from the housing in a parallel state; and a light guide projecting from the two light guides in a parallel state. The snowfall sensor according to claim 1 or 2, wherein 4. The snowfall sensor according to claim 3, wherein an introduction end face of said one light introducing body is disposed to be retracted closer to the housing than an outgoing end face of said two light introducing bodies. 5. A snowfall sensor according to claim 1, further comprising: a signal processing unit for outputting a snowfall intensity signal based on a light receiving signal from the snowfall sensor and a snow / rain discrimination signal from a temperature sensor. Snowfall intensity meter.