JP6604619B1 - Water quality monitoring device - Google Patents

Abstract

It is possible to observe a flow in real time together with an underwater environment with a small and simple configuration. A sensor that measures the water depth and underwater environment and transmits measurement result data as an ultrasonic signal, a receiver that receives an ultrasonic signal from the sensor, a sensor and a connecting thread Elevating device connected to elevate the sensor, a control unit for controlling the operation of the elevating device, an estimation unit for estimating the flow velocity of the sensor received using the sensor water depth data, sensor measurement data and flow estimation It is a water quality monitoring apparatus provided with the communication part which transmits the data of the flow velocity estimated by the part. [Selection] Figure 2

Description

  The present invention relates to a water quality monitoring apparatus capable of observing an underwater environment and flow velocity in real time.

  In the future, fishery production such as tuna and oysters is expected to increase fishery production. To improve the productivity of aquaculture, it is essential to monitor the marine environment in the area where the aquaculture is located. For example, for fish farming, it is necessary to establish a real-time monitoring technology to clarify the relationship between the marine environment and fish growth. On the other hand, although shellfish and seaweed farming does not cost food, monitoring of the marine environment such as the growth environment and red tide is indispensable for improving productivity like fish. In particular, environmental factors such as water temperature, salinity, and chlorophyll fluctuate greatly depending on the flow. Therefore, it is desirable to monitor water quality and flow simultaneously for monitoring the marine environment.

  Various environmental factors such as water temperature and the amount of plankton used as food are involved in the growth of seafood. The water quality sensor can measure the water environment such as water temperature, salinity, chlorophyll (corresponding to the amount of phytoplankton), dissolved oxygen, and pH. Moreover, the water quality monitoring system as described in patent document 1 is proposed for the measuring method. This system uses a small, power-saving water quality sensor with a data transfer function that eliminates the need for a sensor cable. Using the ultrasonic wave, the water temperature and water depth data in the seabed and sea can be obtained at intervals of 1 to several seconds at sea. It is transmitted in real time to the receiving system. As a result, it has become possible to reduce the size and power consumption of an automatic lifting device that has conventionally required a large drum for winding a cable.

Japanese Patent Laid-Open No. 2006-130989

  Conventionally, cost has been reduced by developing a small and lightweight water quality sensor. However, the flow rate indicating the degree of flow has not been measured by such a water quality sensor. As described above, the flow velocity is an important observation item for improving the productivity of the aquaculture industry, and is also an important item for accurate measurement.

  Accordingly, an object of the present invention is to provide a water quality monitoring device that can observe a flow velocity together with an underwater environment while having a simple configuration.

The present invention measures the water depth and the underwater environment, and transmits a measurement result data as an ultrasonic signal;
A receiver for receiving an ultrasonic signal from the sensor;
A lifting device that is connected to the sensor via a connecting thread and lifts the sensor;
A control unit for controlling the operation of the lifting device;
An estimation unit for estimating a flow velocity from a difference between a first water depth obtained from a feeding amount of a connecting yarn of a lifting device and a second water depth measured by a sensor ;
Data flow rate estimated by the sensor measurement data and estimation tough a water quality monitoring system and a communication unit for transmitting.

  According to the present invention, water quality such as water temperature can be monitored in real time, and the flow velocity can be measured. Note that the effects described here are not necessarily limited, and may be any of the effects described in the present specification.

FIG. 1 is a schematic diagram showing a schematic configuration of an embodiment of a water quality monitoring apparatus according to the present invention. FIG. 2 is a block diagram showing the configuration of signal processing according to an embodiment of the present invention. FIG. 3 is a flowchart for explaining the observation pre-processing according to the embodiment of the present invention. FIG. 4 is a schematic diagram used for explaining the flow measurement. FIG. 5 is a flowchart used for explaining the observation operation. FIG. 6A is a graph of the flow measurement result, and FIG. 6B is a graph of the water temperature measurement result. FIG. 7 is a flowchart used for explaining the observation end operation.

  Embodiments of the present invention will be described below. The embodiments described below are preferred specific examples of the present invention, and various technically preferable limitations are given. However, the scope of the present invention is not limited to the following description. Unless otherwise specified, the present invention is not limited to these embodiments.

  FIG. 1 shows a schematic configuration of an embodiment of the present invention. One embodiment is a water quality monitoring device, in which a water quality sensor 1 for measuring an underwater environment is suspended from underwater, for example, an oyster carp, into the sea by a connecting thread, for example, a fishing line 3. In addition, this invention is applicable not only to the culture of shellfish like an oyster, but also to fish culture. The water quality sensor 1 is surrounded by a synthetic resin cover 2 to reduce contamination of the water quality sensor 1. In the drawing, four water quality sensors 1 are shown, but this is for representing different positions of the water quality sensor 1, and usually one water quality sensor 1 is used.

  The water quality sensor 1 includes a circuit part mounted on a printed circuit board and a battery as a power source, for example, a lithium ion secondary battery, in a cylindrical resin case. A sensor (for example, a temperature sensor or a pressure sensor as a depth sensor) and an ultrasonic transmitter for emitting ultrasonic waves into water protrude from one end of the case. The water quality sensor 1 is capable of measuring environmental factors in water such as salinity, chlorophyll (corresponding to the amount of phytoplankton), dissolved oxygen, and pH. Furthermore, the water quality sensor 1 has a tilt sensor. Moreover, you may have an ultrasonic receiver. The inclination sensor is for detecting the angle of the actual position of the water quality sensor 1 with respect to the vertical direction. That is, as will be described later, the inclination sensor measures how much the sensor is inclined due to the flow of the tide, etc., and the flow velocity is determined based on the change in the fishing line length fed from the electric reel 8 and the measured water depth in real time. Presumed.

Furthermore, the water quality sensor 1 includes a CPU (Central Processing Unit), a RAM (Random Access).
Memory), ROM (Read Only Memory), and memory. The memory stores measurement data acquired by the water quality sensor 1 or data obtained by performing processing such as noise removal on the measurement data. The data in the memory is sent to the sensor data receiver 4 that is sent as an ultrasonic wave by an ultrasonic transmitter after undergoing processing such as necessary modulation, and is suspended at a predetermined depth in the sea within the ultrasonic reach. Is received. Similarly to the water quality sensor 1, the sensor data receiver 4 may be moved up and down by an automatic lifting device. In order to save power, the sensor is designed to operate only when it is present in the water by a timer or an external start command, and the data measured at 0.1 second intervals are averaged at 1 second intervals. Transfer data using sound waves.

  The mechanical and electrical devices for the offshore portion of the water quality monitoring device are installed on the aquaculture cage 5. That is, as shown in FIG. 2, a solar panel 6, a battery (secondary battery) 7, an electric reel 8 as an example of an automatic lifting device, a cleaning pump 9 for cleaning the water quality sensor 1, a communication and control module 10 It is composed of The communication and control module 10 controls each part of the water quality monitoring device and controls communication via the cloud server 21. The communication and control module 10 includes a CPU 11. The sensor and the electric reel 8 are controlled by a built-in built-in module, and further, measurement control and data transfer to the cloud server are performed by a mobile gateway (main controller) having a CPU corresponding to the Linux OS. Do.

  The control by the CPU 11 can be represented by functional blocks such as a power supply control unit 12a, a data communication unit 12b, an automatic elevation control unit 12c, a measurement data processing unit 12d, and a cleaning control unit 12e. The power controller 12 a controls the power controller 13. The battery 7 and the power input terminals of the electric reel 8 are connected to the power controller 13. The power generated by the solar panel 6 is stored in the battery 7 and used as a power source for each part of the water quality monitoring device. A predetermined voltage (for example, +12 V) is supplied to the electric reel 8 by the power controller 13. Although not shown, the power of the battery 7 is supplied as power to each part of the water quality monitoring device such as the communication and control module 10. Further, ON / OFF of the power supply of the water quality monitoring device can be controlled by the communication and control module 10.

  Since the electric power required for driving the electric reel 8 depends on the observation frequency and the measurement water depth (related to the driving time per one time), the power consumption according to the characteristics of the aquaculture target is estimated, and the power saving time is long. Drive is achieved. As an example, when performing regular observation, hourly measurement is desired. However, since there is a limit to the power generation amount and battery capacity of the solar panel 6 that can be installed, for example, measurement is performed every 2 hours or every 4 hours. In addition, the remaining power of the battery is constantly monitored, and if power necessary for observation is not left, the observation is canceled until the battery voltage is restored to a predetermined level.

  Sensor data received by the sensor data receiver 4 is supplied to the ultrasonic transducer 14, subjected to processing such as demodulation and A / D conversion, and supplied to the CPU 11. Sensor data is processed in the measurement data processing unit 12d of the CPU 11. In the measurement data processing unit 12d, a vertical profile of the marine environment from the sea surface to the sea floor is created. The vertical profile is a change in observation data such as water temperature according to the water depth. Further, in the measurement data processing unit 12d, the flow velocity is estimated using the inclination data from the water quality sensor 1.

  Observation data such as vertical profile data and flow velocity data is converted into a wireless transmission signal by the data communication unit 12b, and the wireless transmission signal is transmitted to the cloud server 21 by the antenna 15. As the radio system, a mobile communication line, a satellite communication line, or the like is used. If a farmer accesses the cloud server 21 using a terminal such as a smartphone 22, observation data such as the water quality and flow velocity of the farm can be monitored in real time.

  The automatic raising / lowering control unit 12c of the CPU 11 controls the raising / lowering operation of the electric reel 8. That is, the depth of the water quality sensor 1 is measured in real time using the ultrasonic data transfer function, and the elevation of the sensor between the sea surface and a predetermined water depth (for example, within a range of 10 to 100 m) is automatically controlled. A fishing line 3 to which a water quality sensor 1 is connected is wound around an electric reel 8. As the fishing line 3, PE thread that has little elongation and high durability is used. By using the electric reel 8 for fishing, it is possible to significantly reduce the size and power consumption compared to the conventional winder. The water quality sensor 1 is designed to be driven only when it exists in water for power saving. For example, the data measured at intervals of 0.1 second is averaged at intervals of 1 second, and the sensor is used by using ultrasonic waves. Data is transferred to the sea via the data receiver 4.

  Further, the automatic elevating control unit 12c measures the load applied to the fishing line and the electric reel and the feed length of the thread in real time, and automatically recognizes the seabed and obstacles to perform avoidance control. In addition, the water quality sensor 1 is lowered immediately below the sea surface at regular times, and the sea condition (sea level calmness and current strength) is estimated from the amount of movement and fluctuations in the measured values of each water quality. Judge automatically.

  Further, the operation of the cleaning pump 9 is controlled by the cleaning control unit 12e. That is, as a countermeasure against attached organisms to the water quality sensor 1, a function of always holding the sensor in the atmosphere except during measurement and a device for automatically washing the sensor unit at the start and end of measurement are provided.

The observation start determination process performed by the CPU 11 will be described with reference to the flowchart of FIG.
Step ST1: Processing is started at a preset time.
Step ST2: The power of the water quality monitoring device is turned on.
Step ST3: The main controller (CPU 11) is activated.
Step ST4: The data communication unit 12b communicates with the cloud server 21 to establish communication. In this case, parameters necessary for observation are received from the cloud server 21.

Step ST5: Control is performed so that the water quality sensor 1 descends to a predetermined depth by the automatic elevation controller 12c. For example, it is lowered to 50cm below the sea level and stopped.
Step ST6: Sensor data from the water quality sensor 1 is collected. For example, water depth data and slope data are collected.

  Step ST7: It is determined whether or not the water quality sensor 1 is normal depending on whether or not the sensor data has been normally collected. If it is determined that the process is not normal, the process proceeds to step ST11. If it is determined that the process is normal, the process proceeds to step ST10.

Step ST10: Normal observation processing is performed.
Step ST11: An observation end process is performed. In other words, the cloud server 21 is notified that the observation has ended abnormally, and the administrator or the farmer is notified of the abnormal end through the smartphone 22. Moreover, the water quality sensor 1 is withdrawn from the sea.
Step ST12: The power of the water quality monitoring device is turned off.

  The above-described observation start determination process (particularly, the sea condition determination in step ST9) determines whether or not the conditions are suitable for observation. It is known that data transfer from the sea using ultrasonic waves becomes unstable due to bubbles in the water. As the cause of the bubble generation, wave splash, rapid flow change, and the like are cited. In order to avoid instability of data transfer due to air bubbles, the wave height is measured from changes in water depth and the flow is measured from slope data at the start of observation. For example, the observation start conditions are assumed to be a wave height of 0.5 m or less and a flow velocity of 1 knot (speed of about 50 cm per second). If the conditions are not satisfied, the observation is canceled.

  The flow velocity estimation method will be described with reference to FIG. The estimation of the flow velocity is performed in the measurement data processing unit 12d of the communication and control module 10. The flow velocity estimation method according to the present invention described below has a simple configuration and can reduce the cost.

  If the flow of the flow velocity V exists in the direction from left to right in FIG. 4, the water quality sensor 1 is caused to flow by an angle θ with respect to the vertical direction. The angle θ is measured by an inclinometer built in the water quality sensor 1. Since the angle θ is proportional to the flow velocity V, the flow velocity V can be estimated using the data of the angle θ. For example, the flow velocity V can be estimated from θ by obtaining the relationship (conversion coefficient) between θ and the flow velocity V in advance through a demonstration experiment in a flowing water tank and on-site, and storing it in a memory or the like.

  Further, the feeding amount of the fishing line 3 from the electric reel 8 is represented as W0. The feed amount W0 can be obtained by conversion from the number of rotations of the electric reel 8. Further, the feeding amount W0 may be obtained by determining the color classification of the fishing line 3 by an image sensor. Since the distance Δh calculated by Δh = W0 sin θ is proportional to the flow velocity V, the flow velocity V can be estimated from the value of Δh.

  Furthermore, when estimating the flow velocity V in the present invention, it is not necessary to use an inclinometer. The theoretical water depth obtained from the feed amount of the fishing line 3 is represented by D0. On the other hand, the actual water depth obtained from the data of the pressure sensor provided in the water quality sensor 1 is represented by D1. When there is no flow, (D0 = D1). If there is a flow, then (D0> D1). These differences (ΔD = D0−D1) are obtained. Since the difference ΔD between the flow velocity V and the water depth is in a proportional relationship, the flow velocity V can be estimated from the difference ΔD.

  The normal observation process (step ST10 in FIG. 3) performed under the control of the CPU 11 will be described with reference to the flowchart of FIG. As an example, the process for measuring the vertical profile of the flow velocity described above will be described. In FIG. 5, the flow velocity is expressed as a flow.

Step ST21: Start of flow observation Step ST22: For example, the water quality sensor 1 is lowered at a speed of 0.2 m / sec.
Step ST23: It is determined from the observation data of the pressure sensor of the water quality sensor 1 whether it is the flow measurement water depth. For example, when the flow is measured every 1 m, the flow is measured at each of the water depths of 1 m, 2 m,. In addition, a predetermined water depth is set as the lowest layer of flow observation.

Step ST24: When it is determined that the water depth is the flow measurement, the descent of the water quality sensor 1 is stopped and the flow measurement is performed. If the water depth of the flow measurement has not been reached, the process returns to step ST22 and the water quality sensor 1 is further lowered.
Step ST25: It is determined whether or not the measured flow is larger than a preset threshold value, for example, 1 knot.
Step ST26: If the determination result in Step ST25 is Yes, it is determined that the flow is too strong to be accurately observed, the water quality sensor 1 is pulled up to the sea, and the observation is stopped.

Step ST27: It is determined whether it is the lowest layer. For example, a water depth of 100 m is set as the lowermost layer. When the determination result of step ST27 is No, the process returns to step ST22, and the descent of the water quality sensor 1 is resumed.
Step ST28: If the decision result in step ST27 is Yes, the water quality sensor 1 is raised at a speed of 0.2 m / sec, for example.
Step ST29: It is determined from the observation data of the pressure sensor of the water quality sensor 1 whether or not it is the flow measurement water depth. For example, when the flow is measured every 1 m, the flow is measured at each of the water depths of 99 m, 98 m,.

Step ST30: When it is determined that the water depth is the flow measurement, the rise of the water quality sensor 1 is stopped and the flow measurement is performed. If the water depth of the flow measurement has not been reached, the process returns to step ST28 and the water quality sensor 1 is further raised.
Step ST31: It is determined whether or not the measured flow is larger than a preset threshold value, for example, 1 knot. If the determination result in step ST31 is Yes, it is determined that the flow is too strong for accurate observation, and in step ST26, the water quality sensor 1 is lifted to the sea and the observation is stopped.

Step ST32: If the determination result in step ST31 is Yes, it is determined whether or not it is the top layer. For example, the uppermost layer is set above the sea level (that is, zero water depth). When the determination result of step ST32 is No, the process returns to step ST28, and the rising of the water quality sensor 1 is resumed.
Step ST33: When the determination result in step ST32 is Yes, an observation end process is performed.
Step ST34: The power of the water quality monitoring device is turned off.

  In addition, since the marine environment changes from moment to moment, data transfer at intervals of one second sometimes occurs at intervals of several seconds on the receiving side. In order to cope with this unstable data transfer, the flow and time change required for data transfer are constantly monitored, and if these fluctuations exceed the specified values, the immediate observation is stopped and the sensor is raised. Also good.

  If the load applied to the electric reel 8 exceeds the specified value when moving up and down, the lifting is stopped immediately to avoid trouble, and trouble information and the like are sent to the cloud server 21 on land via the mobile gateway (main controller). The information may be transferred and notified to the administrator or the farmer via the smartphone 22.

  FIG. 6A schematically shows an example of a flow measurement result (vertical profile) as a graph. The vertical axis is the water depth, and the horizontal axis is the flow velocity. Since the water depth of the flow measurement is discrete, the flow velocity is also obtained as a discrete value. However, for simplicity, FIG. 6A shows one profile of descending and ascending.

  FIG. 6B schematically shows an example of a vertical profile of water temperature as a graph. The vertical axis is the water depth, and the horizontal axis is the flow velocity. Since the temperature change of water temperature is measured continuously, it becomes a continuous curve graph. Further, both a profile at the time of lowering (solid line) and a profile at the time of rising (broken line) are shown. In the present invention, the measurement result is not limited to being obtained as a vertical profile, but the water quality sensor 1 may be fixed at a predetermined water depth, and temporal changes such as flow velocity and water temperature may be observed.

The observation end process (step ST11 in FIG. 3) will be described with reference to FIG.
Step ST41: The observation end process starts.
Step ST42: The cleaning pump 9 is operated and the water quality sensor 1 is cleaned by the cleaning pump 9.
Step ST43: The power supply of the electric reel 8 is turned off.
Step ST44: The remaining amount of the battery 7 is checked.

Step ST45: The observation data is compressed and filed.
Step ST46: The measurement data obtained by the process at step ST45 is transmitted to the cloud server 21. In addition, the device status data of the water quality monitoring device is transmitted together with the measurement data.
Step ST47: When the above processing is completed, all the power supplies are turned off.

  One embodiment of the present invention described above can measure the flow with respect to the water quality sensor 1 with a simple configuration. The flow measurement data obtained can improve the accuracy of real-time monitoring of water quality and improve the reliability of observation data. In addition, by monitoring the flow in real time for the fisherman, it is possible to predict the growth of fish and shellfish and to perform effective feeding.

  Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments, and various modifications based on the technical idea of the present invention are possible. For example, the water quality monitoring device is not limited to being mounted on the anchor, but may be mounted on a ship or mounted on a drone. Further, the process of stopping the measurement when the measured flow is larger than a preset threshold value may be performed in the same manner in observation of water temperature other than the flow. The configurations, methods, steps, shapes, materials, numerical values, and the like given in the above-described embodiments are merely examples, and different configurations, methods, steps, shapes, materials, numerical values, and the like may be used as necessary. .

DESCRIPTION OF SYMBOLS 1 ... Water quality sensor, 3 ... Fishing line, 4 ... Sensor data receiver, 5 ... Reed, 6 ... Solar panel, 7 ... Battery, 8 ... Electric reel ,
10 ... Communication and control module, 11 ... CPU

Claims (5)

A sensor that measures the water depth and the underwater environment, and transmits the measurement result data as an ultrasonic signal;
A receiver for receiving an ultrasonic signal from the sensor;
An elevating device connected to the sensor via a connecting thread and elevating the sensor;
A control unit for controlling the operation of the lifting device;
An estimation unit that estimates the flow velocity from a difference between a first water depth obtained from the amount of feeding of the connecting yarn of the lifting device and a second water depth measured by the sensor ;
Water quality monitoring device comprising a communication unit and for transmitting the data of flow rate estimated by the measurement data and the previous Ki推 tough of the sensor. The sensor has an inclinometer;
An angle formed with respect to the vertical direction of the sensor is detected by the inclinometer,
The water quality monitoring apparatus according to claim 1, wherein the estimation unit estimates the flow velocity based on the angle. At the start of measurement, the sensor is lowered to a predetermined depth, and the flow velocity at the predetermined depth is estimated by the estimation unit,
The water quality monitoring apparatus according to claim 1 or 2 , wherein the measurement is stopped when the estimated flow velocity is larger than a threshold value. During the measurement, the flow velocity is estimated by the estimation unit,
The water quality monitoring apparatus according to any one of claims 1 to 3 , wherein the measurement is stopped when the estimated flow velocity is larger than a threshold value. The water quality monitoring apparatus according to any one of claims 1 to 4, wherein a flow velocity at each of a plurality of water depths is estimated by the estimation unit.

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