JPH0751025B2 - Watering equipment for crops - Google Patents

Description

The present invention relates to a method of irrigation effective for irrigation of agricultural crops such as greenhouse cultivation, watering of horticultural crops and ornamental plants, irrigation of mushroom cultivation, and the like. It is related to the device.

2. Description of the Related Art As one of conventional methods of irrigating crops, a method of irrigating a fixed amount at regular time intervals determined empirically is generally used. Although the equipment is simple, this is performed regardless of the amount of moisture retained in the soil and changes in the environment of the crops, and thus there is a drawback that excess or deficiency may occur, which may cause poor growth or quality deterioration. Avoid these drawbacks,
A method is known in which the degree of dryness of the soil in which the crop is planted is measured, and when the water content in the soil falls below a certain amount, a certain amount of water is supplied. As an apparatus based on this method, as shown in FIG. 4, an evaporation container 50 filled with water is placed near the crop, and electrode rods B ₁ to B ₃ having different lengths are placed on the evaporation container 50.
The tips of these electrode rods are immersed in water so that B ₃ is the deepest and B ₁ is the shallowest. Then, the detector 54 detects the resistance change (several KΩ → ∞) between B ₂ and B _3, and the controller 54
53 sends an opening signal to the electromagnetic valve 56, water supply to the container 50 is started, the detection signal is also input to the controller 55, the irrigation valve 57, for a certain set time from the controller 55, An irrigation instruction signal is issued to open the valve 57. Then, the water level in the evaporation container 50 rises, and the detector 51 detects a change in the resistance value of B ₁ and B ₃ (∞ → several KΩ), so that the controller 53 closes the electromagnetic valve 56. There is known an irrigation device configured to send a success signal to complete water supply and thereafter repeat the same operation.

However, in this device, the electrode B ₁ to be detected
From the bottom, the distance between the water surface to the lower end of the B ₂ are typically 1mm
The difference in detection level before and after is extremely small. Therefore, the surface tension of water causes an error in the detection of the amount of evaporation caused by the water rising up the electrode rod. The minute particles are deposited in the form of fine unevenness, which is caused by a capillary phenomenon, which causes a detection error caused by sucking up water, or water replenishment is performed every time the level difference 1 corresponding to the amount of evaporation is detected. However, there are various drawbacks in that an error in the amount of make-up water occurs every time, and this appears as an error in detecting the amount of evaporation.

In Japanese Patent Publication No. Sho 46-23010, a constant-capacity evaporation dish and a mercury switch are installed on the left and right of the balance, and the balance tilts every time the water containing liquid fertilizer injected into the evaporation dish evaporates. A hydroponic mechanism is disclosed in which a switch is turned on, whereby water containing liquid fertilizer is supplied to the crop.

However, this device balances the amount of water in the evaporation dish and the mercury switch, and when the balance is lost,
Since it has a configuration such that a mercury switch is turned on, when this is applied to general upland cultivation and greenhouse cultivation, it is not easy to adjust the amount and interval of irrigation according to the characteristics of various crops, In addition, every time evaporation is repeated, precipitated crystals such as dissolved fertilizer appear as an error, and the accuracy is gradually lowered.

Further, Japanese Utility Model Laid-Open No. 2-71228 discloses an irrigation device which measures a weight reduction due to evaporation of filling water in an evaporation tank to detect an irrigation time. In this device, the initial water surface level, which is the reference value for measuring the amount of evaporation, is fixed by setting the opening of the communication pipe that communicates with the evaporation tank. Thus, when the weighing value indicates a preset value, the irrigation signal is output and water is supplied to the evaporation tank each time to restore the initial water level.

With this device, the initial water level is repeatedly set physically for each degree of irrigation, and by treating it as a constant value, the control means can be simplified and irrigation that accurately reflects humidity can be performed. However, there is a possibility that a minute change in water level may occur due to the influence of wind, vibration, or deposits on the opening of the communication pipe, and the initial value may fluctuate, which may prevent accurate watering.

OBJECT OF THE INVENTION It is an object of the present invention to overcome the above problems of the prior art and to disclose an automatic irrigation system capable of performing accurate irrigation in accordance with soil desiccation and water demand of various crops. It is a thing.

Structure of the invention The gist of the present invention is to place an evaporation container on a weighing machine installed in the vicinity of a growing place of a crop, and to expose the evaporation container to water replenishing means for replenishing water. Is provided with a weighing value output means for continuously measuring the weight of the evaporation container filled with water, converting the measured value into an electric signal and outputting the electric signal, and the output signal from the weighing value output means and the latest Generates an irrigation signal that activates the irrigation means for a predetermined time each time the experimentally determined predetermined evaporation amount is detected by comparing the measured value at the time of irrigation or the measured value after the water supply stop signal is output. Means, irrigation means for irrigating the crops based on the output signal of the irrigation signal generating means, and the weighing value output means are connected to this output signal, and the preset upper limit value of the water level of the evaporation container and Compared with the weighing value corresponding to the lower limit value, When the weighing value is within the range of the lower limit value set as a numerical value having a predetermined width that is larger than the predetermined evaporation amount, and when the signal of the irrigation signal generating means is output, Provided are water replenishment signal generation means for generating a water replenishment start signal to the water replenishment means, and water replenishment stop signal generation means for generating a water replenishment stop signal to the water replenishment means when the weight measurement value is equal to or more than the upper limit value. There is an automatic irrigation device characterized in that there is.

An embodiment of the device of the present application will be described below in detail with reference to the drawings.

Embodiment FIG. 1 shows an irrigation system showing an embodiment of the present invention,
The weighing machine 1 has a load cell as a weighing value output means 3 for converting a load into an electric signal and outputting the electric signal to an evaporation container 2 composed of a water container placed on the weighing table 1a. The weight of the container 2 is converted into an electric signal by a strain gauge and a bridge circuit, and this signal is further converted from analog to digital and output to a microcomputer as the control unit 4. The control unit 4 is a well-known microcomputer, and has a serial I / O interface for inputting and outputting a weight measurement signal from the weighing machine 1, a central processing unit (CPU) for performing control and calculation, a program, and a weight measurement of an evaporation container It is composed of a memory for storing values (measured values) and the like. The control unit 4 will be described with reference to a block diagram showing its function and a flowchart of an operation program stored in the memory.

The measured value output signal is temporarily stored in a RAM (random access memory) for measurement values sampled at fixed time intervals Δt, and integrated at fixed time intervals (ΣΔt).
Prevents erroneous detection due to temporary vibration and shaking, and makes it an effective weight measurement value (weighed value). Therefore, the measured value is Δt
It will be updated every time (Steps 20, 23, 2
8). The weight measurement value thus obtained is input to the irrigation signal generation means 5, and the weight reduction value of the first evaporation container where the measurement is started is used as a reference to compare with this, and the weight reduction value is calculated as the evaporation amount (step 24). ). It is determined whether or not this evaporation amount has reached a predetermined experimentally determined evaporation amount (step 25), and each time the predetermined evaporation amount is reached, the irrigation device 6 is stored for a certain time set and stored in the memory. A irrigation signal is output to the irrigation valve 6b which is a normally closed electromagnetic valve so as to open the irrigation valve provided in the water pipe 6a (step 26). This is done via a relay circuit or the like not shown.

On the other hand, the measured value is also input to the water replenishment signal generation means 7 and the water replenishment stop signal generation means 8 (step 20). For the former,
In order to prevent the evaporation container 2 from becoming empty, the weight of the evaporation container 2 at the lower limit of the water level is set as a numerical value within a certain range having a width slightly larger than the set evaporation amount, and the lower limit value When comparing with the weighing value (step 21) and determining that the weighing value has reached the lower limit range (Y side in step 21), the water supply pipe facing the evaporation container 2
9a, to the water replenishment means consisting of a water replenishment valve 10 consisting of a normally closed electromagnetic valve interposed between the water pipe 20 and
A water supply signal is output (step 27). The signal is sent from the I / O interface of the microcomputer to the water supply valve 10 via a relay circuit (not shown), and the valve 10 is opened to start water supply. On the other hand, the water supply stop signal generating means 8
, The upper limit of the water level of the evaporation container is set, and it is checked whether the weight measurement value exceeds this upper limit (step 29). If it coincides with, a water supply stop signal is output (step 30). Specifically, this is performed by sending a release signal for the self-holding state to a relay circuit (not shown) that continues sending an opening signal to the water supply valve 10.

The irrigation signal generation means 5 is set to operate preferentially with respect to the water replenishment signal generation means 7, and the lower limit value which is the operation requirement of the water replenishment signal generation means 7 is
Since it is set as a numerical value having a range slightly larger than the predetermined evaporation amount, which is the operation requirement of the irrigation signal generating means 5, when the water replenishing operation is performed, it is always performed immediately after the irrigation operation. The weighed value when the water supply is stopped becomes the reference value for calculating a new evaporation amount. In this way, the evaporation container 2
The crop is automatically irrigated each time a certain amount of water evaporation from is detected. Aside from the operation of irrigation, when the water in the evaporation container is reduced below a certain limit, the water replenishing means automatically replenishes the evaporation container with water up to the specified water level. Thereafter, this operation is repeated to perform irrigation.

In the above example, the correlation between the evaporation amount and the irrigation amount varies depending on the type of crop, the condition of the growing place of the crop, the season, etc., so that these conditions can be appropriately selected and used for each condition. It is desirable to set it in the microcomputer so that the user can select and use it.

Effect According to the irrigation system of the present application, the irrigation condition can be finely and easily determined or changed by changing the program of the microcomputer or by setting the selection condition as described above. . Furthermore, in order to determine the appropriate period of irrigation, the amount of change from the reference value is constantly calculated as the amount of evaporation based on the weight of the evaporation container at the time of the immediately preceding irrigation, and it is calculated every time the set amount of evaporation is reached. Since the irrigation is performed in the same way, it is not affected by foreign substances that tend to enter the evaporation container, the measurement error is small compared to the conventional device, and the chance of error is drastically reduced. Can be done and produce good quality crops. Further, as a weighing machine, a commercially available electronic balance having high precision can be used, so that there is an excellent effect that the manufacturing is easy.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of the irrigation system according to the present invention. FIG. 2 is a flow chart showing the operation of the microcomputer of the embodiment apparatus of FIG. FIG. 3 is a side view showing the external appearance of the embodiment apparatus of FIG. FIG. 4 is an explanatory diagram showing an example of a conventional technique.

Claims (1)

[Claims] 1. An evaporation container is placed on a weighing device, and water supply means is exposed to the evaporation container, and the weighing device continuously measures the weight of the evaporation container containing water. A weighing value output means for converting the measured value into an electric signal and outputting the electrical signal is provided, and the output signal is compared with the weighing value at the time of the latest irrigation, or by comparing the weighing value after outputting the water replenishment stop signal described below. Connecting irrigation signal generating means for activating the irrigation means for a predetermined time each time a predetermined evaporation amount is detected, irrigation means for irrigating a crop based on the output signal of the irrigation signal generating means, and the weighing value output means Then, the output signal is compared with the weighing value corresponding to the upper and lower limits of the preset water level of the evaporator, and the weighing value of the evaporation container is a numerical value having a range over a range larger than the predetermined evaporation amount. Within the range of the lower limit set as , A water replenishment signal generation means for sending a water replenishment start signal to the water replenishment means when the signal of the irrigation signal generation means is output, and a water replenishment stop signal to the water replenishment means when the weighing value is equal to or more than an upper limit value And a water replenishment stop signal generating means for sending water.