JP6915783B2 - Humidity sensor device for agricultural house - Google Patents

Description

The present invention relates to a humidity sensor device for an agricultural house, specifically, a humidity sensor device for an agricultural house provided with a fan in a storage housing of the humidity sensor.

As a fan control system using a conventional humidity sensor, for example, the dehumidifying / drying system described in Patent Document 1 is known.
This dehumidifying and drying system includes a container for accommodating paddy, a ventilation unit for forcibly introducing air in the greenhouse into the container, a dehumidifier for dehumidifying the air in the greenhouse, and a dehumidifier in the greenhouse. A warmer for warming the air, a ventilation fan for ventilation in the greenhouse, an IC-type temperature sensor for detecting the atmospheric temperature in the greenhouse, and an atmospheric humidity in the greenhouse. It is equipped with a humidity sensor such as an impedance change type and a controller that controls the operation of the ventilation fan and the ventilation unit based on the control information of the temperature sensor and the humidity sensor.

Japanese Unexamined Patent Publication No. 2007-247941

However, in such a conventional dehumidifying and drying system, the following problems have arisen.
In other words, the humidity sensor only detects the humidity in the greenhouse and controls the operation of the ventilation fan to ventilate the greenhouse. There was a risk of malfunction. Since the humidity sensor has a polymer capacity type humidity detection element or the like, it will lead to its failure in a high humidity atmosphere.

Therefore, the inventor has found that the operation of the humidity sensor becomes unstable in a high humidity atmosphere, and by disposing a fan in the housing for accommodating the humidity sensor and controlling the operation of the fan, the above-mentioned problem This invention was completed in order to solve the problem.

An object of the present invention is to provide a humidity sensor device for an agricultural house capable of maintaining normal operation of a humidity sensor even in a high humidity atmosphere.

The invention according to claim 1 is a house humidity sensor installed in an agricultural house to detect the humidity of the internal space of the agricultural house, a housing for accommodating the house humidity sensor, and a housing housed in the housing. In a house humidity sensor device including a day illuminance sensor that detects the day illuminance in the agricultural house and a fan that is housed in the housing and discharges the air inside the housing to the outside of the housing, the day illuminance sensor. The day and night are discriminated by, and at night, the fan is driven and operated when the humidity inside the housing is low, the fan operation is stopped at high humidity, and the fan operation is controlled so that the fan operation is turned on during the daytime. It is a humidity sensor device for an agricultural house equipped with a control means.
Humidity sensors can be broadly classified into two types: polymer resistance type and polymer capacitance type. Both use a hygroscopic material (high molecular polymer, etc.) that absorbs and dehumidifies moisture, and has a structure that bridges the electrodes and is sealed with resin. The polymer resistance type humidity sensor captures the electric signal by the electric resistance, and the polymer capacitance type humidity sensor captures the electric signal by the electric capacity.
The former has a simple structure, can be mass-produced, and is relatively inexpensive. Resistant to noise to measure electrical resistance. Therefore, the sensor unit can be miniaturized, and the sensor cable can also be thinned. However, in principle, it is not possible to measure 10 to 20% or less.
The latter has a fast response speed. It can be used in high temperature and low temperature range. Excellent for low humidity measurement. It is vulnerable to noise because it measures capacitance. Therefore, shielding is required and cables are thick.
Agricultural greenhouses are so-called vinyl greenhouses that grow vegetables and fruits, and are also a concept that includes greenhouses and the like. This house humidity sensor shall include a temperature / humidity sensor. The housing can be made of, for example, a plastic box.
The illuminance sensor is, for example, an analog illuminance sensor having a built-in photodiode and a current amplification circuit.
The reason for using the day illuminance sensor instead of the clock to distinguish day and night is that adding the clock function is costly, the clock setting and management are required, and the clock setting using the battery. It is necessary to keep the time, and it is difficult to recover when there is a deviation such as a delay in the clock (there may be a deviation in the protocol such as universal time). A day illuminance sensor that can reflect the situation at the site is preferable.
Judgment of high humidity / low humidity refers to a case where detection and measurement become unstable, for example, with a capacitance type humidity sensor. For example, the humidity is 90% to 92%. This is a case where the resin-sealed moisture-sensitive material and electrodes become unstable.

The invention according to claim 2 is the invention according to claim 1, wherein the housing has an exhaust port, the fan is provided facing the exhaust port, and the air inside the housing is discharged from the exhaust port by operating the fan. Humidity sensor device for houses.
An exhaust port of a predetermined size is formed on one surface of the housing, and a fan is arranged so as to face the exhaust port. The control means for controlling the operation of the fan includes, for example, a control circuit of a control board arranged in the housing, a program of a CPU mounted on the board, and the like.

The invention according to claim 3 is the house humidity sensor device according to claim 1 or 2, further comprising a communication circuit board for transmitting the sensor signal inside the housing.
The board for the communication circuit can also be arranged and stored in the housing. The heat generated from the circuits of these boards is released to the outside by discharging air to the outside by a fan. Communication is a concept that includes wired and wireless.

According to the inventions of claims 1 to 3, even when the inside of the agricultural house is in a high humidity atmosphere, the load on the humidity sensor can be controlled so as not to be excessive by properly operating and controlling the fan. Moreover, since the fan is driven in the daytime, heat generated from the circuit or the like is always discharged to the outside. At night, the atmospheric temperature drops, so the humidity tends to be higher than in the daytime. Therefore, by controlling the operation of the fan, the humidity sensor can prevent the trouble that occurs, and the durability of the humidity sensor can be improved. The temperature and humidity inside the housing are almost the same as those at the housing installation position inside the agricultural house. Enables proper temperature and humidity measurement. By providing a circuit board for communication with the outside, it is possible to control the operation of the fan directly from the external terminal by the command signal from the external device obtained from the sensor signal.

It is a top view which shows the sensor device which concerns on one Example of this invention. It is a side view which shows the sensor device which concerns on one Example of this invention. It is a front view which concerns on one Example of this invention. It is a rear view which shows the sensor device which concerns on one Example of this invention. It is a perspective view which shows the housing box of the sensor device which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the sensor device which concerns on one Example of this invention. It is a flowchart for demonstrating operation of the sensor apparatus which concerns on one Example of this invention.

Hereinafter, an embodiment of the humidity sensor device for a house according to the present invention will be specifically described.

In FIGS. 1 to 5, reference numeral 11 denotes a humidity sensor device, which is suspended and arranged inside an agricultural house, for example, on the ceiling thereof. The sensor device 11 has a housing 12 made of a plastic plate made of a rectangular parallelepiped, and inside the housing 12, a temperature / humidity sensor 13, an electric fan 14, an ambient light sensor 15, and outputs of these sensors (not shown) are output. It houses a communication unit that transmits to an external terminal via an internet line, a circuit board that has a control circuit for driving a fan, and the like. Further, as a power source for these devices, for example, an external power source installed in a house can be used. It can also be supported by an internal power supply.
An exhaust port 16 that communicates inside and outside is formed at a predetermined height position on one side surface of the housing 12, and an intake port 17 is formed at a predetermined position (a position away from the exhaust port) on this side surface or another side surface. ing. The fan 14 is fixed at a side position facing the exhaust port 16. Further, on the side surface of the housing 12 in which the ambient light sensor 15 (sunlight sensor) is arranged, a thin and translucent light acquisition window 18 is formed to detect external light. When the fan 14 is driven and rotated, the external air sucked into the internal space of the housing 12 from the intake port 17 is discharged from the exhaust port 16 into the agricultural house outside the housing.

The temperature / humidity sensor 13 is a commercially available resin-sealed semiconductor sensor, and uses a resistance change type of an electric humidity sensor. However, even that of the capacitance change type is acceptable.
The role of the fan 14 is to dissipate heat generated by the sensors 13 and 15 themselves due to energization, to dissipate heat generated from the board circuit inside the housing, and to create an atmosphere around the sensor outside the housing (housing 12). The purpose is to bring it closer to the atmosphere of the area to be measured.
As the ambient light sensor 15 as the daily illuminance sensor, a commercially available product is used.

The control means of the fan 14 can be configured by a control circuit formed on the substrate or a circuit (stored program) incorporated in the semiconductor chip fixed to the substrate.
The ambient light sensor 15 measures the daily illuminance in the house and discriminates between day and night.
That is, the fan 14 is turned on when the humidity is less than 91% or the daily illuminance is 50 lux or more. Further, the condition that the fan 14 is turned off is that the humidity is 91% or more and the daily illuminance is less than 50 lux (at night). It should be noted that nighttime can be determined as, for example, less than 20 lux.
This is because the inside of the housing (housing 12) is heated by the influence of sunlight in the daytime, so the fan 14 is always turned on to avoid temperature error, and the humidity 91 is used to protect the humidity sensor device from high humidity at night. This is to prevent the high humidity atmosphere from being taken into the housing when the temperature is less than%. If it is less than 91%, the fan 14 is turned on, not only day and night.
That is, the control means turns on the fan 14 when the humidity is less than 91% or the daily illuminance is 50 lux or more. The condition for turning off the electric fan 14 is nighttime (the daily illuminance may be less than 50 lux, particularly the illuminance may be 20 lux or less), and the humidity is 91% or more. At night, the humidity is turned off at a high humidity of 91% or more, and the fan is turned on at a humidity of less than 91%, for example.
The threshold values for determining humidity and daily illuminance can be changed as appropriate, depending on the environment of each individual house and other circumstances.

FIG. 6 is a block diagram for explaining a control concept in the sensor device according to the embodiment of the present invention. That is, the control means is composed of, for example, a CPU or the like, and the input signal from the sensor is used to calculate according to the flowchart of FIG. 7, and the drive signal ON and stop signal OFF are output to the fan for control. ..
In addition to the control circuit formed on the board as described above and the above software control incorporated in the chip, it is also possible to control from an external terminal (for example, a smartphone or a personal computer) via an internet line, for example. ..
Alternatively, the terminal user can manually operate the terminal screen to turn on / off the fan at an arbitrary timing.
This is to restart the control by the signal from each of the above sensors by manually turning off the fan at the time of spraying the pesticide and turning it on again at the end of spraying. In addition, it is used as an emergency measure (fail-safe function) when the automatic control fails.
Further, the fan can be turned on / off by a command from a server connected via an internet line.
When the fan ON / OFF control becomes complicated, this control can be performed from an external server having high processing capacity. In this case, even if a trouble occurs in the day illuminance sensor, the nighttime is determined by the clock function of the external server or the like.
The most common electronic sensor as the electric humidity sensor is a capacitive and resistant sensor used for public meteorological observation. Both of these use porous ceramics or a hygroscopic polymer film as a moisture sensitive body.
The capacitive sensor applies an AC voltage between two plate-shaped electrodes that sandwich the moisture sensitive body, and the humidity changes from the change in capacitance between the electrodes caused by the change in the dielectric constant due to the moisture absorption of the moisture sensitive body. To measure.
The resistance sensor utilizes the change in conductivity associated with the moisture absorption of the moisture sensitive body. The measured values obtained by these are visualized by an ordinary measuring instrument (capacity meter / resistance meter) or a data acquisition board.
Due to the nature of the measurement principle, an error due to temperature change is unavoidable, and in order to suppress this within 0.2% of humidity per 1 ° C of temperature change, the actual product has a correction mechanism using a temperature sensor. In addition, although a filter is attached to the moisture-sensitive body, it is inevitable that it will change over time due to surface contamination, etc., so regular maintenance and calibration are required.

The humidity sensor device for an agricultural house according to the present invention is useful as a humidity sensor device technology.

11 Humidity sensor device,
12 housing,
13 Humidity sensor,
14 fans,
15 Ambient light sensor.

Claims (3)

A house humidity sensor installed inside an agricultural house to detect the humidity in the internal space of this agricultural house,
The housing that houses this house humidity sensor and
A day illuminance sensor that is housed in this housing and detects the day illuminance in the agricultural house,
In a house humidity sensor device that includes a fan that is housed inside the housing and exhausts the air inside the housing to the outside of the housing.
The day and night are discriminated by the day illuminance sensor, and the fan is driven to operate when the humidity inside the housing is low at night, the fan operation is stopped at high humidity, and the fan operation is turned on during the day. Humidity sensor device for house with control means to control. The humidity sensor device for a house according to claim 1, wherein the housing has an exhaust port, the fan is provided facing the exhaust port, and the air inside the housing is discharged from the exhaust port by operating the fan. The house humidity sensor device according to claim 1 or 2, further comprising a communication circuit board for transmitting the sensor signal inside the housing.

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