WO2010049957A1

WO2010049957A1 - Device and method for monitoring and controlling a plant for farming and/or conservating fishery species

Info

Publication number: WO2010049957A1
Application number: PCT/IT2008/000676
Authority: WO
Inventors: Raffaele Acierno; Vincenzo Zonno
Original assignee: Tecno.S.E.A. S.R.L.
Priority date: 2008-10-30
Filing date: 2008-10-30
Publication date: 2010-05-06

Abstract

A device and a method for the monitoring and control of a fish farming and/preservation installation are described. A local control unit includes a PAC controller connected to sensors and actuators that respectively detect and regulate the environmental parameters of interest.

Description

"DEVICE AND METHOD FOR MONITORING AND CONTROLLING A PLANT

FOR FARMING AND/OR CONSERVATING FISHERY SPECIES"

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DESCRIPTION Field of Invention

The present invention concerns a device and a method for the monitoring and control of a fish farming and/or preservation installation.

For example, the invention finds application in aquaculture activities carried out in land-based plants, where fish are bred in tanks or closed basins, as well as in activities carried out in the open sea, in lagoons or in lakes, where the fish are grouped in "chambers" or "tanks" delimited by nets or the like. As in many other production sectors, that of aquaculture also exploits modern technologies to automate certain productions processes, such as the monitoring of the chemical-physical parameters of the farming environment, the control of farming conditions, product selection and other aspects related to this type of activity.

Control of the farming environment is fundamental for ensuring maximum productivity, increasing production process efficiency and avoiding risks of losing farmed stock. Except for a few small-scale situations, all aquaculture companies currently implement more or less sophisticated automatic monitoring and control systems.

For example, the environmental parameters of greatest interest for fish farming in tanks are:

• oxygen content of fish-farming water;

• temperature offish-farming water; and • pH of fish-farming water.

Maintaining these parameters within optimal limits is fundamental for production quality and capacity, whilst exceeding certain thresholds results in sufferance and, without prompt action, the death of the farmed species. Prior Art Monitoring and control systems are normally applied to all modern aquaculture installations to automate the numerous and continuous operations that are necessary for ensuring the optimal state of farming conditions.

The technology that is used in nearly all applications of this type is that of the Programmable Logic Controller (PLC), an electronic device specialized in the control of industrial processes. The PLC executes a program that processes digital and analogue signals arriving from sensors and, depending on the processing results, activates certain actuators that start or stop a process.

A classic example of application in aquaculture is that of a PLC connected to an oxygen sensor and a solenoid valve: when the level of oxygen dissolved in the fishfarming water drops below a preset threshold, the PLC activates the opening of a solenoid valve in the oxygenation circuit.

One of the factors that have fostered the diffusion of the PLC in the industrial automation environment is its sturdiness. In fact, the PLC is normally located on control boards in noisy environments with a lot of electrical interference and high temperatures or high humidity. In certain cases, on plants that must never stop, the PLC operates round the clock, 365 days a year.

Over time, with the progressive miniaturization of electronic components and cost reductions, the PLC has also appeared in domestic use for the automatic control of many installations and systems installed in houses, such as heating systems, burglar alarms, irrigation systems, lighting systems and similar. Normally, a PLC has a compact structure that comprises the I/O modules, the interfaces and the control module. Unlike the first PLCs that had limited calculation and I/O control capabilities, modern PLCs use more advanced microprocessors (CPU) that permit greater calculation, I/O control and network communications capabilities and the use of more advanced programming languages. Due to the calculation capacity, which in any case is limited, and the rigidity of hardware configurations, with few exceptions, the PLC-based monitoring and control systems adopted in aquaculture use single-channel PLCs, or rather those able to manage a single sensor and a single actuator (Fig. IA). Today, the majority of PLCs are programmed via one the various languages defined by the IEC-61131-3 standard, the most widespread of which is "Ladder Logic". PLCs are very common in the industrial application environment and are virtually inevitable in many industrial processes that range from packaging to assembly line part identification and control. Currently, approximately 80% of industrial applications comprise digital I/O, some analogue I/O and relatively simple programs. Many PLCs utilize relatively simple microprocessors, such as the AMD 2901, and also a rather simple programming language, such as Ladder Logic.

Despite its wide diffusion, the PLC still has rather limited flexibility and ease of use. The structure of the PLC is often adapted according to the process to be automated. Boards suitable for the electrical quantities involved are chosen during the design of a control system. The various boards are then assembled to form each PLC; if it should become necessary to measure different quantities or add further functionality, it will be necessary to redesign the PLC or use another one especially configured for such purposes.

The PLC can also be equipped with a small display on which the currently measured value can be read. If it wished to monitor the set of all analysis and control activities of all the PLCs installed on a system, and possible take action on them, it is necessary to use a personal computer and specially developed interface software.

This personal computer is usually connected to the various PLCs via a local network.

If it is wished to use the monitoring and control interface from a different workstation, it is necessary to install the software on another personal computer and connect this to the first one via modem or ADSL (Fig. IB).

Usually, when it is necessary to resolve automation and control problems that go beyond the limits of the PLCs₅ it is preferred to investigate different alternatives, such as the use of a personal computer (PC) for example.

In fact, thanks to their possibilities of much greater hardware and software customization with respect to PLCs, PCs offer much higher capabilities and flexibility for creating control systems for industrial processes. On the other hand, the use of a PC for industrial automation tasks presents problems of bulk, hardware fragility and software stability that render its applicability in a realtime production environment almost impossible. Summary of Invention

That having been said, the object of the present invention is to propose a device and a method for the monitoring and control of a fish farming and/or preservation installation that allows greater flexibility in programming and setting up the control procedures.

Another object of the present invention is to propose a device and a method of the above-said type that can be easily used and adapted even by operators with little experience in the field of automation and process control.

A further object of the present invention is to propose a device and a method of the above-said type that can also be easily connected and interfaced with control systems already installed in existing installations. These objects are achieved by the present invention thanks to a device according to claim 1 and a method according to claim 9. Further aspects and characteristics of the invention are specified in the respective independent claims.

The monitoring and control device according to the present invention is based on PAC ("Programmable Automation Controller") technology and comprises advanced interface software expressly developed for the automatic monitoring, analysis and management of production process parameter alarms and controls. PAC controllers offer the same reliability and sturdiness of PLCs, but greater processing capabilities, versatility, flexibility and ease of use. PACs are control modules of the (real-time) deterministic type that are true computers, equipped with input/output (I/O) modules and "intelligent" interfaces. These systems are capable of acquiring, filtering, calibrating and converting analogue and digital signals in any unit of measurement, as well as performing self- diagnostics. The "network-oriented" architecture of a PAC based system makes it directly integrable with the Internet. In fact, PACs can independently connect to a physical Ethernet network, through which they can communicate with each other or with any other computer on the network via standard transmission protocols, such as TCP/IP. The PACs' high processing capabilities allow a single control module (the equivalent of a PLC) to control a large number of sensors or actuators. All this provides: • data acquisition and analysis and deterministic actuator control (real-time), • access to modules and data from any computer connected to the Internet, • connectivity of any analogue or digital sensor/actuator without the need for hardware reconfiguration,

• practically unlimited programming versatility and flexibility, and

• containment of installation and running costs. According to a first aspect of the present invention, a monitoring and control device is thus proposed for fish farming and/or preservation installations, comprising a plurality of sensors for measuring environmental parameters of interest, one or more actuators for the regulation of one or more environmental parameters of interest and at least one local control unit connected to the sensors and actuators. The PAC controller is conveniently included in the local control unit.

The device also comprises at least one remote control unit connected to the local control unit, preferably via the Internet, using a wireless connection. The connection between the two control units usefully permits programming of the local control unit via the remote control unit, the remote monitoring of the conditions of the controlled installation, the possible modification or updating of threshold values for environmental parameters subjected to control and the immediate notification of any anomalies in these parameters or, in any case, the exchange of data and/or programs between the two control units. For example, the remote control unit can consist of a personal computer or an advanced type of mobile peripheral, such as a palmtop, a smart-phone or the like, able to dialogue with the local control unit also via the mobile phone network. According to another aspect of the present invention, a monitoring and control method is also provided for fish farming and/or preservation installations, in which provision is made for the measuring of environmental parameters of interest through a plurality of sensors, the regulation of one or more environmental parameters of interest through one or more actuators and the control of the environmental parameters by at least one local control unit connected to the sensors and actuators. Management of the monitoring and control process is entrusted to a PAC controller included in the local control unit. Thanks to the characteristics of greater versatility, calculation capability and customization, a PAC-based monitoring and control system proves to be less expensive and simpler to install and manage, and allows superior analysis and control capabilities to those of the numerous PLCs that would be needed to provide the same capabilities. In fact, one of the more evident advantages of PACs is that, unlike PLCs, each one of them can handle a significant number of sensors and actuators, thereby considerably reducing costs for the necessary hardware. Brief Description of Drawings

Further characteristics and advantages of the present invention will become clearer from the description that follows, made by way of non-limitative example with reference to the enclosed drawings, where: - Figures IA and IB are diagrams that show the basic characteristics of systems of the known type based on PLCs;

- Figure 2 is a diagram that highlights the connection characteristics between a PAC controller and the series of sensors and actuators connected to it; and

- Figure 3 is a diagram that shows the architecture of a control device according to the present invention.

Modes for Carrying Out the Invention

Figure 2 schematically shows the connections of a PAC controller, to which a plurality of sensors l...n and a plurality of actuators l...n subjected to control can be simultaneously connected. Upon comparing with the diagrams in Figures IA or IB, the advantage offered by a PAC controller can be seen immediately, namely the possibility of connecting any number of sensors and any number of actuators to a single device, while according to known art, it necessary to use a PLC type controller for each sensor and/or for each actuator. Sensors used in the device according to the invention can, for example, include sensors for measuring water-related parameters in one or more zones of the installation, for example, temperature, oxygen content, salinity, acidity or the like, as well as sensors for measuring external atmospheric conditions around the installation, presence sensors, or even sensors, such as cameras or the like, for providing images or videos of the installation to the remote control unit. In turn, the possible actuators can include pumps, solenoid valves, optical and/or acoustic indicators or, in any case, motors in general, which are operated, for example, in order to maintain and/or restore environmental parameters of interest. Figure 3 shows the architecture of a device according to the present invention in which the relation between the local control unit 10 and one or more remote units, comprising for example a plurality of personal computers 20, a Web/FTP server 30 and a database 40, is highlighted.

A communications device 15 can also be connected to the local control unit 10 to allow dialogue between the local control unit 10 and the other remote units. Alternatively, the communications device 15 can be incorporated directly in the local control unit 10. The communications device 15 can consist, for example, of a modem able to connect to one of the available networks and can, for example, consist of a modem suitable for GPRS, EDGE, UMTS, satellite or the like types of connection, or consist of an ADSL modem/router, possibly equipped with an integrated access point, for direct connection to the Internet. The main distinguishing characteristics between a device according to the invention and the more common PLC-based systems for aquaculture are:

• having a native operating system and application system software just like a personal computer;

• greater data processing and logging capabilities; • control algorithms, data analysis and signal processing integrated in the controller;

• native graphical user interface;

• reduced costs per controlled sensor/actuator;

• reduced bulk and connection cables; • Web and FTP interfaces for remote control from any PC connected to the Internet;

• interfacing with external applications; and

• intrinsic and native self-configuration and data acquisition and logging capabilities. In the following, the characteristics of an actually constructed embodiment of a device according to the present invention are described by way of example, highlighting the advantageous aspects with respect to known art. Hardware Characteristics

The device embodied according to the present invention is based on Compact FieldPoint (cFP)™ PAC technology distributed by National Instruments. The cFP is a compact, modular and expandable PAC₅ developed for measurement, industrial control and data logging applications that demand reliable and sturdy hardware. The device is composed of a series of sensors and actuators, positioned locally or remotely distributed, and connected to a PAC controller. As already mentioned, unlike a PLC, a PAC controller is a true computer in miniature, equipped with a processor, volatile memory, mass storage, network cards, serial ports, operating system and application software. All of this endows the device with high performance characteristics and greater ease of use and management in virtue of the high intrinsic capabilities of self-checking, real-time operation and networking for I/O distributed in various ways. Unlike PLCs, in addition to its operating system, the cFP controller employed has pre-installed application system software that provides the device with extensive data acquisition and storage functionality without the need for specific programming. The device automatically recognises all of the system's I/O modules, adapting the data acquisition and control procedures to the individual I/O channels that it automatically detects, eliminating the need for configuration, which is indispensible for PLCs.

Once powered up and connected to the respective sensors, the device's I/O modules acquire, filter and calibrate the various types of raw signals and transform them into units of the measured quantities through opportune scaling and compensation operations, without the need for specially provided software, as the device is already equipped with a series of application system functions.

The I/O modules, which are also able to carry out self-diagnostic operations on themselves and on certain sensors, can be "hot-swapped" (i.e. substituted without stopping the acquisition and control system). The device will recognise the change and will reconfigure itself to reflect the new configuration.

A single PAC controller like the one used can directly handle up to 64 sensors and the same number of actuators, with a considerable drop in costs per sensor/actuator with respect to a system based on PLCs. Furthermore, thanks to a simple Ethernet connection, the number of I/O channels that can be handled by a single PAC can grow unlimitedly up to the maximum processing capacity of the PAC itself. This ability to handle many channels with a single controller allows the entire device to have much less bulk with respect to a similar PLC-based system, saving a significant amount of space and connection cables.

Another important advantage of the device is represented by the intrinsic potentiality of network connections and publication on the Internet. Through the device's network interface, all measurements can be automatically published, and in real-time, on a private or public network. In the same way, it is possible to access any of the system's I/O channels from any computer on the private or public networks, whatever* the distance. Networking characteristics As already mentioned, a complex system such as that for the monitoring and control of an aquaculture installation based on PLCs calls for the use of a computer equipped with specific interface software, specifically assigned to monitoring the set of all analysis and control activities of the various PLCs and taking action on them when required. Use of the interface from a workstation other than that normally assigned to this task requires installation of the interface software on another PC, which must necessarily be connected to the first one via modem or ADSL.

Conversely, in the device according to the invention, the interface software resides and runs on the PAC itself and, thanks to the system's Ethernet/TCP -IP connectivity, it is possible to access the monitoring and control interface for the entire system from any computer connected to the Internet and without the need to install specific software, thereby offering more or less unlimited accessibility to all of the system's individual sensors, with the possibility to monitor, carry out checks, activate actuators, reprogram all sensors/actuators in real time, etc. The architecture of the device allows the logging of all acquired data and events activated by a number of control modules on one or more external databases, as well as the display and control of applications from any PC connected to the Internet using a generic web browser. This intrinsic network orientation makes the system itself much more versatile and economic, reducing the installation of hardware and software, and at the same gives it practically unlimited remote accessibility. Advanced system management interface

In addition to the base interface originally present in the cFP series PAC controllers, the device also uses an advanced interface for the management of trigger thresholds, historic data analysis, alarms management, etc. The advanced interface is developed using a software development platform (Lab VIEW™) that allows analysis and control software to be created with virtually unlimited customization in a simple and effective manner.

The ease of use of the programming platform allows analysis and control programs to be created without the need for particularly advanced programming knowledge, thereby allowing the user to modify the interface software and the analysis and control software at any time.

These characteristics make the device's advanced interface easily customizable according to the specific characteristics of the different production situations in which the system might be installed. It should also be taken into consideration that the advanced interface also resides on the device's controllers and can be displayed and used by any computer on the Internet via a simple web browser.

The advanced interface software, like any other specific application software, is created on a normal PC and then transferred to the CPU of the PAC controller to run autonomously in real-time mode. In order to maximize efficiency in hardware-software functional relations, the PAC hardware used in the monitoring and control device has the following distinguishing characteristics:

• graphics support capability: it is possible to simplify the development of efficient and highly customizable user interfaces; • measurement versatility (high-speed data acquisition, vision and motion): allows standard analogue measurements (voltage and current), shape and colour analysis and movement analysis (vibration, displacement, etc.) to be incorporated in the same system;

• calculation capability: usage in applications where particularly complex control algorithms or large signal management capabilities are required, with the possibility of incorporating external program code and to log both locally and on remote PCs;

• compatibility with different PAC hardware and with PLCs; and

• communications capability, thanks to tools such as TCP/IP, OPC and SQL/ODBC. Graphics capability

Graphics represent the natural way of representation for man. This concept is applicable both to the description of a sequence or process (flow diagrams and block diagrams) and to the use of a user interface for any type of equipment. The device is programmed by means of the Lab VIEW™ graphical development environment, in which the control process is defined through the interconnection of specific function-blocks. In addition, Lab VIEW™ allows the creation of graphical user interfaces (GUI) including all the controls and indicators required by a specific application for user interaction (control panel). The greatest advantage of this development environment consists in the possibility programming systems integrated in the controllers, and also in being able to offer a graphical user interface via Web thanks to the integrated web server or a true remote control panel. LabVIEW™ supports various communications standards, including TCP/IP, UDP, OPC and Active X, which allow data to be transmitted from the controller to a GUI residing on a PC client or to a SCADA type control system. Measurement capability

Another advantage of the device according to the invention with respect to a system based on PLCs derives from the greater capability of the former to execute and process complex measurements. In virtue of this capability, it is possible, for example, to combine heterogeneous measurements such as frequency, waveform, voltage, amperage, image identification, measurements of surfaces and volumes of static or dynamic objects, object motion, speed, acceleration etc., into a single control system. This constitutes an incomparable level of customization with respect to a system based on PLCs, in terms of the types of signal that can be handled and processed using the hundreds of functions available for their analysis and information extraction. The possibility of integrating visual data, impossible with PLCs, allows, for example, monitoring the integrity of the nets that constitute mariculture cages, automatic size- based selection, identification of morphological anomalies in specimens and the sudden occurrence of danger conditions in the breeding tanks (presence of algae, particulate, predators, etc.). In addition to this, the development environment allows the integration of control algorithms with complex signals such a wave generation and modulation, digital pattern identification and reading and the acquisition of special physical quantities. Calculation capability The CPU of the cFP used in the embodied example is a 200-Mhz Pentium processor with floating point unit, capable of simultaneously executing hundreds of controls of the Proportional-Integral-Derivative type (PID controls), with a time resolution that can arrive to process 1000 cycles per second.

In virtue of the intrinsic capability of working with floating point numbers, this processor is able to "naturally" manage the risk of overflow that can occur during calculations and to correctly size the number of decimals in order to avoid possible blockage of the system.

The functions available for programming include arithmetic operations, Boolean logic, linear algebra, array operations and approximately 450 high-level analysis functions for scaling, filtering, statistics, transformations, peak identification and signal generation and image analysis algorithms. Hardware compatibility

Thanks to the characteristics of the development environment, the device's applications are able to run indifferently on various platforms, such as PocketPC, palmtops, PCs and PXI devices with real-time operating systems. Communications capability

The device is able to dialogue with external applications and to log all data on a local or remote database via ODBC/SQL. In addition, TCP/IP and OPC allow the integration of external systems and communications with them. The system automatically publishes the I/O data on an OPC server resident on a computer connected to the network. As OPC is supported by many SCADA or Windows applications and is very common in industrial automation hardware, it is very easy to integrate the cFPs with different industrial automation platforms, such as PLCs for example.

AU of the system's controllers incorporate a web server that allows monitoring and control of all the sensors and actuators from any computer connected to the Internet by means of a normal browser and without the need to install a specific program.

Lastly, another strongpoint of the system consists in the possibility of direct connection to a wireless network, which allows links to be created between the controller and public or private networks even when there is no wired network, a characteristic that is extremely useful for applications in remote or difficult to access areas (field activities, at sea or on a lake, etc.). Practical advantages of device

Summarizing, the device according to the invention is based on cFP PAC technology and applies an innovative approach to breeding and fish-farming environments for aquatic species to guarantee optimal conditions and health and, in consequence, the quality and efficiency of the production processes.

The device is actually structured as a series of sensors that continuously detect preset parameters (temperature, oxygen, images, etc.) and actuators (solenoid valves or video cameras etc), able to take action on the farming conditions. Due to its structural characteristics, the system is very flexible and customizable in configuration and is able to support a large number of measurements and sensors. The developed monitoring and control system has the following strengths with respect to traditional systems: • greater versatility and ease of use in terms of:

O interfacing with all types of sensors and actuators, including video cameras or cameras (not just measurement probes);

O data processing and management (not just logging and transfer): O user interface implementation and management;

• reduction in the number of hardware components and overall bulk (it is possible to install it inside a small waterproof panel, whilst traditional systems require the installation of cabinets or booths), with reduction of the visual environmental impact and the maintenance of complex integrated systems;

• visibility and control from any computer connected to the Internet (the system has its own autonomy and allows data to be transferred, shared and displayed directly via the Internet, without the need of any remote PC or specific program);

• wireless connection capability (does not require long connection cable runs to be laid in the farming installations to connect the stations and the PLCs, with a consequent reduction in the environmental impact related to plant decommissioning) ;

• utilization of purpose-built, low-cost, high-efficiency temperature probes; and

• capability of a single PAC to control a theoretically unlimited number of I/O channels (and consequently lesser bulk and economic investment).

AU of the advantageous aspects illustrated until now result in a reduction in plant and maintenance costs with an operational efficiency exceeding that of a traditional system and intrinsic innovation that puts the traditional management of fish-farming installations abreast of the times. With regards to the PAC systems, which are now mature and widely used in the industrial field, their useful application in aquaculture has also been noticed, where the optimal control of farming calls for the monitoring of an ever-increasing number of heterogeneous parameters and rather complex algorithms that integrate various types of measurement. The applicant has created an automatic monitoring and control system for environmental parameters in aquaculture applications based on PAC technology. Thanks to the extreme versatility, this monitoring system can also be easily extended to the control of parameters such as the quantities of effluent water in aquaculture installations, in this way integrating the management of water used for production, from point of origin to discharge, in a single system. In this configuration, the system allows the reutilization of purified effluent waters (recirculation) to be automatically managed on the basis of physical/chemical parameters measured in real time. Even though developed for aquaculture installations, the system can easily be customized for utilization in large aquariums and, in any case, for measuring and controlling environmental parameters in water.

Claims

1. A monitoring and control device for a fish farming and/or preservation installation, comprising a plurality of sensors for measuring environmental parameters of interest, one or more actuators for regulating one or more environmental parameters of interest and at least one local control unit connected to said sensors and to said actuators, characterized in that said local control unit includes at least one PAC controller.

2. The device according to claim 1, in which at least one remote control unit connected to said local control unit is provided.

3. The device according to claim 1 or 2, in which said local control unit is connected to said remote control unit via the Internet.

4. The device according to claim 1 or 2, in which said local control unit is connected to said remote control unit via a wireless connection.

5. The device according to claim 1 or 2, in which said local control unit can be programmed by said remote control unit.

6. The device according to claim 1 or 2, in which said local control unit includes means for generating signals representing possible anomalies in said environmental parameters and means for transmitting said signals to said remote control unit.

7. The device according to claim 1 or 2, in which said remote control unit includes a personal computer.

8. The device according to claim 1 or 2, in which said remote control unit includes a mobile peripheral.

9. A monitoring and control method for a fish farming and/or preservation installation that provides for the measuring of environmental parameters of interest by means of a plurality of sensors, the regulation of one or more environmental parameters of interest by means of one or more actuators and the management of said environmental parameters by at least one local control unit connected to said sensors and to said actuators, characterized in that said local control unit includes at least one PAC controller.

10. The method according to claim 9, in which a connection is provided between said local control unit and at least one remote control unit.

11. The method according to claim 9 or 10, in which the connection between said local control unit and said remote control unit is implemented via the Internet.

12. The method according to claim 9 or 10, in which the connection between said local control unit and said remote control unit is implemented via a wireless connection.

13. The method according to claim 9 or 10, in which said local control unit can be programmed by said remote control unit.

14. The method according to claim 9 or 10, in which said local control unit generates signals representing possible anomalies in said environmental parameters and transmit them to said remote control unit.