JPH02253188A - Method for detecting fallen snow state - Google Patents

Abstract

PURPOSE:To efficiently control thaw by arranging a pair of electrodes on the fallen snow surface in a part to be thawed and detecting the electric resistance between electrodes and detecting the light reflection factor and the light reflection intensity of the fallen snow surface by a photometric sensor. CONSTITUTION:A light reflection factor M is detected and is combined with an electric resistance RS to detect the fallen snow state. That is, a fallen snow surface 2s of a concrete C is whitened and the reflection factor M is increased according as snow lies. Since the electric resistance RS is reduced then, fallen snow is distinctly detected. In this case, outputs of discriminating circuits 33 and 36 go to '1' together, and thereby, the output of an AND gate 34 goes to '1'. Thus, power is supplied to a heater for auxiliary heat source.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for detecting snow cover conditions for efficiently controlling snow melting equipment and the like.

[Prior art and issues]

Various snow melting devices for melting snow from roads, roofs, etc. have been known for a long time, and for example, a snow melting/freezing device for efficiently melting snow from the approach from the gate to the entrance has already been published by the applicant in Utility Model Application No. 18507/1983. It is proposed in the official bulletin. This device has the heat collecting part of the Heat Vibe buried underground at a predetermined depth, and the heat dissipating part is placed in the area to be melted snow.The heat collecting part is also equipped with a heater as an auxiliary heat source, which provides assistance during heavy snowfall. A heat source heater is activated to efficiently melt snow.

By the way, in order to control such an auxiliary heat source heater that does not need to be operated all the time, it is necessary to accurately detect snow conditions and
By operating only when necessary, you can reduce power consumption.
Extremely efficient.

For this reason, snowfall is detected using a snowfall detector such as that disclosed in Japanese Patent Application Laid-open No. 50-4.5680, etc.
Depending on this detection result, the snow melting device can be operated.

However, conventional snowfall detectors melt snow that has fallen onto the board using a heater and detect the presence of melted water by measuring electrical resistance, so even if there is a small amount of snow that does not form snow accumulation, The snow melting device operates, making it unsuitable for a snow melting device that is intended to be used as an auxiliary device only during heavy snowfall, such as a heater for an auxiliary heat source when visiting the country, and has the disadvantage of having a complicated configuration and high cost.

In addition, this type of snowfall detector is usually used in combination with a temperature sensor to determine whether it is rain or snow, but in reality, snow falls even when the temperature is high; on the other hand, when the temperature is low However, there was a problem in which it was not possible to accurately detect snowfall conditions because it was raining.

It is an object of the present invention to provide a snow cover state detection method that eliminates the problems existing in the prior art.

[Means to solve the problem]

The snow cover state detection method according to the present invention includes disposing a pair of electrodes 3.4 on the snow surface 2s of the snow melting area 2, detecting the electrical resistance Rs between the electrodes 3 and 4, and detecting the electrical resistance Rs above the snow melting area 2. The light reflectance or light reflection intensity of the snow covered surface 2s is detected by the photometric sensor 11 arranged at It is now possible to detect that the snow is in a state where it should be melted. In this case, the electrode 3.4 exposes the electrode surfaces 3s and 4s at the upper end, is insulated from the snow-melting area 2, and is set higher than the snow-covered surface 2s by a predetermined height Ho.

[For production]

Next, the operation of the present invention will be explained.

According to the snow cover state detection method according to the present invention, the snow melting area 2
3/4 electrodes which are insulated from the snow melting area 2s and whose electrode surfaces 3s143 are set higher than the snow melting area 2s by a predetermined height Ho.
When the electrical resistance Rs between the two ends becomes less than or equal to the set value, moisture present on the snow surface 2s of a predetermined depth or more is detected. On the other hand, since the presence of moisture may be due to rain, etc., the light reflectance M is detected, and when it is equal to or higher than a set value, it is determined that it is snowing.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.

The method of the present invention can be used to detect snow conditions and control the operation of a snow melting device only when there is snow that actually causes a problem. First, Fig. 2 shows an example of a snow melting device E to which the method of the present invention can be used. Refer to and explain.

2 is the area covered by snow melting, and is the area A from the gate to the entrance.
The sidewalk W is not shown. The sidewalk W is made of concrete C, and a plurality of L-shaped heat vibrators 7... have their heat collecting parts 71 buried at a predetermined depth underground, and their heat dissipating parts 7b... are buried in the sidewalk W. Embed it in concrete C along the same line. In addition, the heat collecting part 7a of each heater), vibrator 7,...
・Auxiliary heat source heater 8 is attached in contact with the auxiliary heat source heater 8.
Each heater 8 . . . is connected to a controller 31 . Each of the heaters 8 constitutes a snow melting device E. The controller 31 has a function of controlling energization of each heater 8 .

Next, the configuration of the snow melting control device 1 that determines the snowfall state and controls the energization of the auxiliary heat source heater 8 according to the present invention will be described with reference to FIGS. 1 to 4.

First, a pair of electrodes 3.4 are attached to the sidewalk W.

The electrodes 3.4 shown specifically in FIGS. 3 and 4 are formed of rectangular conductive plates having a predetermined thickness, and both are buried in concrete C with a predetermined width apart and parallel to each other. be done. At this time, the conductor plate is made of an insulating material 2 that has water repellency.
0 to electrically insulate it from concrete C.

This prevents the influence of the concrete C's own electrical resistance (usually on the order of several hundred ohms). On the other hand, the conductor plate of the electrode 3.4 is made to protrude above the snow surface (concrete surface) 2s, and the electrode surface 3s, 4. Expose s. As a result, the electrode surfaces 3s and 4s are higher than the snow surface 2S by a predetermined height Ho, and the presence of a small amount of moisture, that is, a small amount of snowfall that is not a problem, is not detected. In addition, even if the snow quality is difficult to melt, heat vibration 7... can already be applied to the snow surface for 2 seconds.
Because it is warm, it melts quickly on the snow surface 2s,
A water film forms. The shape of the protruding portion of the electrode 3.4 relative to the sidewalk W is selected so that it does not become an obstacle to walking. On the other hand, the electrodes 3.4 are connected to the controller 31 via wires 23.24, respectively. The controller 31 includes an electrical resistance measuring circuit 32 to measure the electrical resistance Rs between the picture electrodes 3 and 4. This constitutes the electrical resistance detection section 5. Then, the measured electrical resistance Rs is determined by the judgment circuit 3.
In step 3, the measured value is compared with the preset value, and if the measured value is less than or equal to the set value, it is "1", and if it exceeds the set value, it is "0".
is output, and this signal is ANDed via the connection switch 35.
It is applied to the input side of the gate 34.

Further, a reflective photometric sensor 11 using a light emitting element (light emitting part) and a light receiving element (light receiving part) is arranged above the sidewalk W,
This photometric sensor II is connected to the controller 31. The controller 31 includes a light reflectance measuring circuit 35 and measures the light reflectance M from the signal obtained from the photometric sensor 11. This constitutes a light reflectance detection section 9 that detects the snowfall state on the snow surface 2s using the light reflectance M. Then, the measured light reflectance M is compared with a preset value in the determination circuit 36, and when the measured value is greater than or equal to the set value, it is set to "1".
, when it is less than the set value, it outputs "0", and this signal is AN
It is applied to the input side of the D gate 34.

On the other hand, a thermistor 26 is installed at a predetermined location outside, and this thermistor 26 is connected to the controller 31. The controller 31 is equipped with an air temperature measurement circuit 38 to measure the outside air temperature T.
Measure o. This constitutes the temperature detection section 6. Then, the measured outside temperature To is compared with a preset value in the judgment circuit 39, and when the measured value is less than or equal to the set value, it outputs "1", and when it exceeds the set value, it outputs "0", and this signal is It is applied to the input side of the AND gate 34 via the connection switch 37.

Further, the timer section 10 is connected to the controller 31 via a connection switch 41. The timer section 10 has a built-in clock function, and can set an operation time t (operation start time and operation end time). Then, at the set operation start time, 11'',
It outputs "0" at the operation end time, and this signal is applied to the input side of the AND gate 34.

On the other hand, the output side of the AND gate 34 is connected to the auxiliary heat source heater 8 through an output circuit 42 and a relay 43.

In the above configuration, each of the connection switches 37 and 41 selectively connects the temperature measuring section 6 and the timer section 10 to the AND gate 34, so that they can be used as necessary depending on the climate, construction location, etc. It is.

Next, a snow cover state detection method according to the present invention will be explained.

First, when there is no snowfall, the electrical resistance Rs is in an insulated state, and the output of the determination circuit 33 is "0", so the AND
The output of the gate 35 also becomes "0", and the auxiliary heat source heater 8
...is not energized. That is, snow conditions are not detected.

On the other hand, in the case of snowfall, the snow covered surface 2s of the sidewalk W gets wet, and when the snow accumulates to a certain extent, the amount of water increases due to the snow melting action of the heat pipe 7, the electrical resistance Rs between the electrodes 3 and 4 decreases, and the output of the determination circuit 33 decreases. It becomes rlJ. In addition, in this case, the sidewalk W
Since it is constantly warmed by the snow melting action of the Heat Vibe 7 itself, there is no need to use the auxiliary heat source heater 8 in the case of a small amount of snowfall, and it is necessary to increase the heating capacity only in the case of heavy snowfall. Depending on the installation mode of electrode 3.4,
A small amount of snow that does not accumulate and a small amount of snow that does not cause problems in real life are not detected. That is, as the snow accumulation progresses, the snow covered area becomes sherbet-like due to the snow melting action of the heat pipe 7, and a water film of a predetermined height is formed.
If the height HO of the electrode surfaces 3s and 4s is selected, a small amount of melted snow water will not be detected, and detection can be performed according to the desired snowfall amount.

Furthermore, when determining based on the electrical resistance Rs, the electrical resistance Rs becomes less than the set value even when a large amount of rainwater is present, as well as snowmelt water due to snow accumulation. Previously, outside air temperature was measured and if it was below a set value, it was determined to be snowfall, and if it was above the set value, it was determined to be rainwater, but when looking at outside air temperature,
There are cases where it does not correspond to snowfall, such as snow falling even when the temperature is relatively high.

Therefore, in the present invention, the snow cover state is detected by detecting the light reflectance M and combining it with the electrical resistance Rs. That is, when snow falls, the snow covered surface 2s of the concrete C becomes white and the light reflectance M also increases. At the same time, the electric resistance Rs also decreases, so that snow accumulation can be clearly detected. In this case, the outputs of the determination circuits 33 and 36 both become "1", and thereby the output of the AND gate 34 becomes "I". Therefore, the auxiliary heat source heaters 8 can be energized. Note that even when the surface of the concrete C is dry and white, the output of the determination circuit 36 is "
1", but in this case, the determination circuit 33 in the detection system of the electrical resistance Rs becomes "0" and does not detect snowfall.

In addition, in the case of rainwater, the surface of the concrete C becomes wet and becomes black, and the output of the judgment circuit 36 in the light reflectance detection system becomes "
0".

By the way, when detecting snow conditions using the above method, the connection switch 37 or 4■ can be selectively turned off as necessary.
NI, each determination element connected to each switch 37, 41 may be added. In this case, the air temperature detection unit 6 using the thermistor 26 gives "1" when the outside air temperature TO becomes below the set value, and the determination result based on the electrical resistance Rs and the light reflectance M indicates the snow cover state, for example. It can be used when you want to check the judgment result when it is detected.

It is also possible to connect and control the timer unit IO.

In general, the time of day when snowfall is most likely to occur has been statistically clarified, and excluding times of heavy snowfall, it is almost always from midnight to early morning. On the other hand, snowfall in the early morning is a problem in real life. Therefore, if the auxiliary heat source heaters 8 are energized only during this time period, snow melting can be carried out efficiently without causing problems in real life. Therefore, [1] is set at the operation start time set by the timer section IO.
If "0" is assigned to the operation end time to the AND gate 34, the auxiliary heat source heaters 8 can be energized only during the predetermined operation time t.

Note that the electric resistance Rs, the outside temperature To, the light reflectance M, and the operating time t may all be combined for determination, or other determination factors may be combined for determination. It is possible to improve reliability and certainty.

Although the embodiments have been described in detail above, the present invention is not limited to these embodiments.

For example, the shape of the electrodes may be a pair of cylindrical electrodes, or a cylindrical and ring-shaped electrode may be coaxially arranged, and the shape and arrangement can be arbitrarily implemented. It is also widely applicable to snow melting devices for other arbitrary uses. In addition, the detailed structure, shape, arrangement, material, etc. may be arbitrarily changed without departing from the gist of the present invention.

〔Effect of the invention〕

As described above, the snow cover state detection method according to the present invention detects the electrical resistance between the electrodes by disposing a pair of electrodes on the snow cover surface of the area to be melted, and also detects the light reflectance with a photometric sensor. Since the snow condition that requires snow melting is detected in accordance with the result, the following effects are achieved.

■ Since the snow melting device can be activated only when snow accumulation poses a problem in real life, it is possible to perform accurate and efficient snow melting control, contributing to reduced power consumption and energy conservation.

■ Since light reflectance is used to determine whether it is rainwater or snow, it is possible to accurately detect snow conditions.

[Brief explanation of drawings]

Fig. 1: A block system diagram showing a snow melting control device capable of implementing the snow accumulation state determination method according to the present invention; Fig. 2: Overall configuration diagram of the snow melting control device; Fig. 3: A plan view of electrodes in the snow melting control device; Figure 4: Vertical cross-sectional view of the same electrode. In the drawing, 2: Snow melting area 2s, snow surface 3° Electrode: Photometric sensor Patent applicant Director of the Agency of Industrial Science and Technology Takemura Manufacturing Co., Ltd.

Claims (1)

[Scope of Claims] [1] A pair of electrodes are arranged on the snow surface of the snow melting area to detect the electrical resistance between the electrodes, and a photometric sensor placed above the snow melting area detects the light reflection of the snow surface. Snow cover state detection that detects snow cover that should be melted when the detected electrical resistance is below a set value and the detected light reflectance or light reflection strength is above the set value. Method. [2] The snow cover state detection method according to claim 1, wherein the electrode surface is exposed at the upper end of the electrode and is insulated from the snow melting area. [3] The snow cover state detection method according to claim 2, wherein the electrode surface is set a predetermined height higher than the snow cover surface. [4] The snow cover state detection method according to claim 1, wherein the photometric sensor is a reflective photometric sensor consisting of a light emitting part and a light receiving part.