WO2019115534A1

WO2019115534A1 - Environment monitoring system, in particular for a watering system

Info

Publication number: WO2019115534A1
Application number: PCT/EP2018/084375
Authority: WO
Inventors: Francesco MOSCIANO; Simone DI DOMENICO
Original assignee: Farm Technologies S.R.L.
Priority date: 2017-12-12
Filing date: 2018-12-11
Publication date: 2019-06-20

Abstract

The present invention relates to an environment monitoring system (100) comprising: a central node (101) and a plurality of sensor nodes (102). The central node (101) comprises: a first wireless communication interface (303), a first controller (302) configured for receiving data through the first wireless communication interface (303) and for transmitting them to a database (1000). Each of the sensor nodes ( 102) respectively comprises: at least one sensor (201) for measuring at least one environment parameter, a second controller (202) connected to the sensor (201) for obtaining data relating to the environment parameter, a second wireless communication interface (203) connected to the second controller (202) and configured for transmitting the data to the central node (101), an electric battery (204) for supplying the sensor (201), the second controller (202) and the second wireless communication interface (203). Each of the sensor nodes (102) further comprises: a switch (205) configured for turning off the sensor (201) and the second wireless communication interface (203), electrically disconnecting them from the electric battery (204), and a time counter (206) configured for flipping the switch (205), electrically connecting the sensor (201) and the second wireless communication interface (203) to the electric battery (204), to turn them on after a predetermined time has elapsed, for obtaining the data and transmitting them to the central node (101). The first controller (302) is further configured for generating an acknowledgement message upon receipt of the data. The first wireless communication interface (303) is configured for transmitting the acknowledgement message to a respective one of the sensor nodes (102). The second controller (202) is further configured for further flipping the switch (205), to turn off the at least one sensor (201) and the second wireless communication interface (203), upon receipt of the acknowledgement message. The present invention also relates to a watering system.

Description

Title: Environment monitoring system, in particular for a watering system

DESCRIPTION

Technical field

The present invention relates to an environment monitoring system, configured according to a network having a central node and a plurality of wireless connected sensor nodes.

In general, the invention relates to a system comprising a plurality of devices interconnected to each other for monitoring parameters of an environment through environment sensors.

In particular, the present invention is used in association with watering systems for agricultural use, which the monitoring system cooperates with to determine the moments in which it is necessary to provide for watering and in which quantity to water.

In that, the present invention also relates to a watering system.

Prior art

Modern agricultural techniques provide for watering of cultivated lands in times of need; however, for an effective use of a precious resource like water, it is advisable to determine the moments in which it is necessary to irrigate and which quantity of water to use to irrigate a given surface.

Watering determination depends on the type of crop, location and type of soil. Additionally, watering determination depends on environment parameters such as air humidity, soil humidity, environment temperature, which are variable, among other things, according to the particular weather conditions.

It is therefore appropriate to measure these and other environment parameters with precision, especially in cultivated plots of land of significant size, where differences between parameters can occur in a portion of land compared to another.

Therefore, network of environment sensors is able to collect measurements from different environment positions and send them to a common location; based on the data collected, it is possible to appropriately control the watering system.

In a network of environment sensors communicating with each other through wireless technologies, the single environment sensors are provided of power supply through batteries.

It is appropriate to do without wired connections between the environment sensors of the network, both for sending signals and for power supply. Indeed, in particular in case of environment monitoring systems installed in cultivated lands, which are outdoor and exposed to the inclemency of the weather, the presence of wired connections is undesirable and may give rise to safety or maintenance problems.

It is understood that any type of environment monitoring system, and not exclusively an environment monitoring system associated with watering systems in cultivated lands, benefits from providing communications through wireless technologies and from supplying single devices through batteries.

However, the known environment monitoring systems encounter a criticality: data transmission through wireless technologies requires higher transmission powers than the transmission through cable technologies to cover a given distance.

Higher transmission powers result in a greater electric energy consumption, which must be provided by batteries provided on board or near the environment sensors.

Therefore, in the known environment monitoring systems, there is a high use of electric energy that forces a frequent replacement and/or recharging of the batteries or an oversizing thereof.

This need for frequent maintenance of the batteries is generally undesirable, especially in case of environment monitoring systems associated with watering systems, where access to the cultivated land is not easy, the position of the environment sensors may be difficult to be localized and the environment sensors may also be very distant from each other. A prior art example dealing with this problem, is provided by document US 7,318,010 (B2), which relates to a method for regulating the use of energy in a wireless sensor network, based on at least one environment parameter used as a decision criterion. Said document provides for defining an“energy management plan”, according to which the sensor nodes must be activated in certain periods and in certain positions, in order to save energy.

However, even the solution suggested by US 7,318,010 (B2) is not optimal, since it requires a complex centralized management of the sensors which leads to a complex operation and possibly to an increase in complexity of the sensor nodes themselves.

Prior art document US 201 1 /238227 (Al) relates to a sensor device for interrupting irrigation and to a method comprising: generating an indication representing the amount of rain fall at a sensor unit; transmitting a signal comprising at least the indication from the sensor unit to an interface unit, wherein the interface unit is adapted to cause an interruption of programmed watering schedules of an irrigation controller; receiving the signal at the interface unit; determining, based at least on the indication from the signal, whether irrigation should be interrupted; and generating an interrupt command to interrupt irrigation.

However, even the solution suggested by US 201 1 /238227 (Al) is not optimal, since it provides for a low battery mode which attempts to reduce power consumption by eliminating or reducing the functions performed and/or the frequency of performing non-essential functions.

Summary of the invention

An object of the present invention is to solve some of the prior art drawbacks.

A particular object of the present invention is to provide an environment monitoring system in which the nodes, communicating through wireless technologies, require low maintenance and a replacement and/or recharging of the batteries delayed over time.

A further particular object of the present invention is to provide an environment monitoring system in which the duration of the electric batteries on board the peripheral nodes is increased.

A further particular object of the present invention is to provide an environment monitoring system that has an effective management of the nodes and sensors associated therewith.

A further particular object of the present invention is to provide an environment monitoring system that has sensor nodes with a reduced structural complexity.

A further particular object of the present invention is to provide an environment monitoring system that defines a communication network between nodes, with an efficient and rational structure.

A further particular object of the present invention is to provide an environment monitoring system particularly suitable for interfacing and cooperating with a watering system, to reduce water waste and optimize the yield of agricultural crops in a land.

These and other objects are attained by an environment monitoring system according to the appended claims, which form an integral part of the present disclosure.

A solution idea underlying the present invention is to provide an environment monitoring system comprising: a central node and a plurality of sensor nodes configured for being connected to the central node.

The central node comprises a first wireless communication interface and a first controller configured for receiving data through the first wireless communication interface and for transmitting them to a database.

Each of the sensor nodes respectively comprises at least one sensor for measuring at least one environment parameter, a second controller connected to the at least one sensor for obtaining data relating to the at least one environment parameter, a second wireless communication interface connected to the second controller and configured for transmitting the data to the central node, at least one electric battery for supplying the at least one sensor, the second controller and the second wireless communication interface. Each of the sensor nodes further comprises at least one switch configured for turning off the at least one sensor and the second wireless communication interface, electrically disconnecting them from the at least one electric battery; a time counter is configured for flipping the at least one switch, electrically connecting the at least one sensor and the second wireless communication interface to the at least one electric battery, to turn them on after a predetermined time has elapsed, and for obtaining the data and transmitting them to the central node.

The first controller is further configured for generating an acknowledgement message upon receipt of the data. The first wireless communication interface is configured for transmitting the acknowledgement message to a respective one of said sensor nodes. The second controller is further configured for further flipping the switch, to turn off the at least one sensor and the second wireless communication interface, upon receipt of the acknowledgement message.

Advantageously, by electrically disconnecting the at least one sensor and the second wireless communication interface in the sensor node, when they are not necessary, the electric energy required for long-term operation is considerably reduced, increasing the duration of the at least one electric battery.

Advantageously, the need for maintenance of the sensor nodes is reduced, delaying the replacement and/or recharging of the batteries; this advantage becomes particularly important in case of use of sensor nodes on agricultural lands, in which they are installed very far from each other.

Advantageously, for supplying the sensor nodes, a simple electric battery, such as batteries of the replaceable type, is sufficient.

In a variant the electric battery of one or more the sensor nodes may be connected to a solar panel of a solar energy charging system, for improving the energy autonomy.

The presence of the time counter which turns the at least one sensor and the second wireless communication interface on allows the sensor node to be brought to a fully operational condition only whenever a predetermined time has elapsed. In this way, advantageously, the sensor nodes are autonomous and do not need external power commands, which should otherwise be received through the second wireless communication interface with further energy waste.

Advantageously, the present invention provides an effective management of the sensor nodes, although only requiring a limited number of components, in particular simplifying the control logic and the computing power of the second controller on board the sensor node.

The second controller flips the at least one switch once again, to turn off the at least one sensor and the second wireless communication interface, upon receipt of the acknowledgement message.

In this way, advantageously, once the data have been safely received by the central node, the sensor node can return to a low-energy consumption mode.

Preferably, the first controller of the central node is further configured for comparing reception instants of the data from different sensor nodes, in particular to verify potential conflicts arising between the data transmission instants for different nodes. In case of potential conflict conditions, the first controller is configured for generating a command message, transmitted together with the acknowledgement message, so that the second controller of the specific peripheral node may modify the predetermined time in reply to the command message, avoiding conflicts. In this way, the environment monitoring system has a simple and at the same time reliable structure.

Preferably the environment monitoring system further provides at least one repeater node, comprising: a third controller, a third wireless communication interface connected to the third controller and configured for receiving data from at least one of the sensor nodes and for retransmitting the data to the central node or to a further repeater node. Advantageously, in this way, even if a sensor node were outside the maximum signal range transmitted by the second wireless communication interface, the presence of a repeater node would ensure the reliable transmission of data up to the central node.

Preferably, the third controller and the third wireless communication interface of the repeater node are continuously supplied by an electric power source, so that the repeater node is always active for receiving and transmitting the data from the sensor nodes. In particular, the electric power source of the repeater node provides a second battery preferably with greater capacity and/or a solar panel and/or an electric cabled connection.

Advantageously, also the repeater node further comprises at least one second sensor for measuring at least one environment parameter, additionally acting as a sensor node to extend the monitoring capability of the system. In particular, the third controller is connected to the at least one second sensor for obtaining second data relating to the at least one environment parameter. The electric power source is further configured for supplying the at least one second sensor and the third wireless communication interface is further configured for transmitting the second data to the central node or to a further repeater node.

In particular, the repeater node has in turn at least one second switch configured for turning the at least one second sensor off, electrically disconnecting it from the electric power source, and a second time counter configured for flipping the at least one second switch, electrically connecting the at least one second sensor to the at least one electric power source, for turning it on after a second predetermined time has elapsed.

Advantageously, also for the repeater node, by electrically disconnecting the at least one second sensor of the repeater, the electric energy required for long-term operation is satisfactorily reduced, thus increasing the duration of the electric power source, particularly in case this is a second battery.

Therefore, the communication network between sensor nodes, repeater nodes and central node has an efficient and rational structure, able to constitute an environment monitoring system particularly suitable for use on large spaces, such as agricultural lands.

Preferably, the sensor nodes or the repeater nodes measure one or more of the following environment parameters: soil humidity, air humidity, air temperature. Preferably, the repeater nodes or the central node additionally measure one or more of the following environment parameters: leaf wetness, rain precipitation (preferably with an accuracy of 0.2 mm). Advantageously, the environment monitoring system is particularly suitable for interfacing and cooperating with a watering system present in the monitored environment.

Preferably, the central node provides a communication network, for instance a cellular network, for transmitting data to the remote database, such as the database of a web application. In this way, a software control engine is able to optimize watering times and ways, based on historical criteria or considering the weather forecast.

The present invention also relates to a watering system, comprising an environment monitoring system according to the present invention.

Further features and advantages will become clearer from the following detailed description of a preferred, but not exclusive, embodiment of the present invention, and from the dependent claims that outline preferred and particularly advantageous embodiments of the invention.

Brief description of the drawings

The invention is illustrated referring to the following figures, provided by way of non-limiting example, wherein:

- Figure 1 shows a diagram of an environment monitoring system according to the present invention.

- Figure 2 shows a diagram of a sensor node according to the present invention.

- Figure 3 shows a diagram of a central node according to the present invention.

- Figure 4 shows a diagram of a repeater node according to the present invention.

- Figure 5 shows a communication protocol of a sensor node according to the present invention.

- Figure 6 shows a communication protocol of a repeater node according to the present invention. In different figures, analogous elements will be indicated with analogous reference numbers.

Detailed description

Figure 1 illustrates a diagram of an environment monitoring system 100 according to the present invention.

The environment monitoring system 100 is preferably installed in a large environment, such as an agricultural land. The elements forming the environment monitoring system, which are accordingly exposed to the inclemency of the weather, will be provided with appropriate measures to ensure integrity and impermeability thereof.

The environment monitoring system 100 is conceived to be part of a hardware and software integrated system for the watering management in agriculture, particularly suitable for use on large terrains.

The environment monitoring system 100 provides three different types of devices, or“nodes”, which communicate with each other through wireless technologies, in particular through radio waves (preferably with a sub-GHz frequency and a range preferably up to 500 m).

The environment monitoring system 100 comprises a central node 101 and a plurality of sensor nodes 102 configured for being wireless connected to the central node 101 and for transmitting and receiving information, as exemplified by the arrows. The environment monitoring system 100 may further comprise at least one repeater node 103, configured for receiving and retransmitting information coming from the sensor nodes 102.

Clearly, the structure of the environment monitoring system 100 is purely exemplary and a different number of nodes can be used, with any configuration and arrangement, in a scalable manner according to the features and dimensions of the environment to be monitored.

The sensor nodes 102 are responsible for the measures in the environment. For the particular application to watering systems of agricultural lands, the sensor nodes preferably measure three environment parameters: soil humidity, air humidity and air temperature. Other measurements are possible, and in a variant the sensor node could also be used as actuator, for instance a hydraulic actuator.

The repeater nodes 103 are configured for“relaunching” the data coming from the nearby sensor nodes, in order to extend the monitoring coverage to a wider field. Preferably, also the repeater nodes are able to carry out measurements in the environment.

The central node 101 is a“gateway” where all the data collected by the external nodes 102 and 103 are received. The central node 101 is configured for sending the data (suitably encrypted) to a database 1000, in particular a remote database of a web application. Preferably through a GSM/ GPRS cellular protocol or another suitable Internet connection, the data are sent to the web application, which stores them on the appropriate database 1000, makes them available to the final user through graphs and interprets them.

In an alternative embodiment, the database could be directly connected to the central node 101 , allowing an interpretation of the data collected through a local application.

In the application to watering systems, the web application is adapted to provide indications for the correct watering management inside the monitored land. Preferably, the database 1000 of the web application may be interfaced with multiple environment monitoring systems according to the present invention, which are separated from each other.

The environment monitoring system 100, in the embodiment cooperating with a watering system, thus contributes defining a monitoring and management system of the“smart” type.

Figure 2 illustrates a diagram of a sensor node 102 according to the present invention, of the plurality of sensor nodes associable with the monitoring system 100.

The sensor node 102 comprises at least one sensor 201 for measuring at least one environment parameter, preferably multiple environment parameters in particular relating to quantities measured in the position where the sensor node 102 is located.

The measured environment parameter, in particular in the embodiment cooperating with a watering system, comprises one or more of the following: soil humidity, air humidity, air temperature, through appropriate sensors.

The sensor node 102 comprises a controller 202 connected to the at least one sensor 201 , configured for obtaining data relating to the environment parameters, in particular in the digital form.

The sensor node 102 comprises a wireless communication interface 203, connected to the controller 202 and configured for transmitting the data to the central node 101 , as already illustrated.

The sensor node 102 then comprises at least one electric battery 204 for supplying the sensors 201, the controller 202 and the wireless communication interface 203. Preferably, the electric battery comprises a pair of AA penlight batteries in series, which provide a nominal voltage of 3

V.

The sensor node 102 comprises at least one switch 205, in particular a pair of switches, configured for turning the sensors 201 and the wireless communication interface 203 off, by electrically disconnecting them from the electric battery 204.

The sensor node 102 further comprises a time counter 206, configured for flipping the switch 205, by electrically connecting the sensors 201 and the wireless communication interface 203 to the electric battery 204, for turning them on after a predetermined time has elapsed. In this way, when the sensors 201 and the wireless communication interface 203 are connected to the electric battery 204, they are turned on and exchange information with the controller 202, and the environment monitoring data are obtained, which are transmitted to the central node 101.

Preferably, the time counter 206 is integrated in the controller 202, which is continuously supplied by the battery 204.

The sensor node 102 could further comprise a local memory (not shown) for saving at least one portion of the data relating to the environment monitoring, as a backup system in case of transmission malfunction.

The controller 202 manages the reception and transmission part, the reading of the ADCs which the sensors 201 are connected to, and the power supply in the‘sleep’ and Svork’ phases by flipping the switch 205, in order to reduce the energy consumption to a minimum and to ensure the operation of the sensor node 102 even for months, only with a pair of AA penlight batteries. The electric consumption of the time counter 206 is much reduced, thus ensuring a limited energy absorption in the ‘sleep’ phase.

The wireless communication interface 203, which represents the vehicle for the information transmitted by the sensor node 102 to the central node 101, is also turned on for a few milliseconds in the Svork’ phase, whereas it is turned off in the‘sleep’ phase, thus further reducing the consumption of electric power. Likewise, the sensors 201 are turned off in the‘sleep’ phase.

Figure 3 illustrates a diagram of a central node 101 according to the present invention, which is associable with the monitoring system 100.

The central node 101 comprises a wireless communication interface 303 and a controller 302 configured for receiving data through the wireless communication interface 303.

The central node then comprises a network communication device 307, such as a GSM module, configured for transmitting the data received at the database 1000.

The central node 101 further comprises a power source 304, such as preferably an electric cabled connection with a voltage of 7- 12 V. The power source 304 allows continuously supplying the controller 302 and the wireless communication interface 303. The power supply 304 further allows continuously supplying the network communication device 307.

The controller 302 is further configured for generating an acknowledgement message upon receipt of the data coming from the sensor node 102. In this case, the wireless communication interface 303 is configured for transmitting the acknowledgement message to the respective sensor node 102 which transmitted the data. In this case, upon receipt of the acknowledgement message, the controller 202 of the sensor node 102 which transmitted the data, further flips the switch 205 for turning the sensors 201 and the wireless communication interface 203 off, switching the sensor node 102 to the‘sleep’ phase. The wireless communication interface 303 is always turned on, to ensure the continuous reception of the data sent by the sensor nodes 102.

The controller 302 manages the reception and transmission part inside the network of nodes, through an RF protocol, by processing the data received and transmitting them to the remote database 1000, in particular though a GSM 307 communication system or another suitable means.

The data sent to the web application operating through the remote database 1000, in particular for application to watering systems, allow a‘real-time’ monitoring of the parameters of the agricultural field.

In fact, in particular, such watering system is configured for distributing water depending on measurements of the environment monitoring system 100, wherein the remote database 1000 preferably processes said measurements .

The environment monitoring system 100 preferably provides an algorithm for managing potential conflicts among data transmitted by the various sensor nodes.

Due to hardware problems linked to tolerances of some electronic components, different wake-up times between node and node may occur; after several cycles and thus several operation hours, this non-ideality would cause an overlapping of receptions by the central node, which may result in a loss of information.

To avoid this problem, in a preferred embodiment, the controller 302 is further configured for comparing data reception time instants, from different sensor nodes 102.

A data reception instant is compared with a preceding data reception instant, previously saved.

If the difference between the instants compared is greater than a predetermined threshold value, then no provision is necessary.

On the contrary, if the difference between the instants compared is less than a predetermined threshold value, then a situation of potential conflict may occur between the current sensor node and the sensor node temporally preceding it in the transmission.

In this case of potential conflict, the controller 302 is further configured for generating a command message, which is transmitted to the sensor node 102 together with the acknowledgement message.

Upon receipt of the command message, the controller 202 of the sensor node 102 is configured for modifying the predetermined wake-up time, in particular just for the successive transmission cycle.

Therefore, the algorithm thus implemented by the different components of the environment monitoring system allows, when fully operational, to equally distance the Svake-up’ times of each sensor node, thus avoiding conflicts.

In this way, the loss of information content is avoided, maintaining the concept of network scalability as a priority. Furthermore, potential conflicts are avoided in each installation phase, in particular when a new sensor node is added, or a damaged node is replaced, since each time a node is turned on may correspond to a loss of synchronization.

Figure 4 illustrates a diagram of a repeater node 103 according to the present invention, of the one or more repeater nodes which are associable with the monitoring system 100.

The repeater node comprises a controller 402 and a wireless communication interface 403, connected to the controller 402 and configured for receiving data from at least one of the sensor nodes 102.

The controller 402 retransmits the data received at the central node 101 or at a further repeater node 103 through the wireless communication interface 403.

The repeater node 103 further comprises at least one electric power source 404 for continuously supplying the controller 402, of the wireless communication interface 403.

The electric power source 404 preferably comprises a second battery or an electric cabled connection. In particular, a 5V battery is provided, which is connected to a solar panel of a solar energy charging system, associated with the repeater node 103, which, though a higher cost of the device, allows improving the energy autonomy.

Preferably, the repeater node 103 further comprises at least one sensor 401, or multiple sensors, for measuring at least one environment parameter, and the controller 402 is connected to the sensors 401 for obtaining data relating to at least one environment parameter.

Therefore, in said preferred embodiment the repeater node 103 is in turn able to perform measurements for the environment monitoring, similar to what has been described for the sensor node 102. Therefore, in the foregoing description it must be understood that some operating criteria of the environment system 100 above described with reference to the sensor node 102 are equally applicable to the repeater node 103, to the extent that the latter also integrates sensor functionality.

The wireless communication interface 403 is further configured for transmitting the data to the central node 101 or to a further repeater node 103.

The electric power source 404 is configured for supplying the sensors 401 and the wireless communication interface 403.

In particular, the wireless communication interface 403 supply occurs continuously, to ensure the reception and retransmission of data coming from connected sensor nodes or repeater nodes.

The repeater node 103 further comprises at least one switch 405, configured for turning the sensors 401 off, by electrically disconnecting them from the electric power source 404.

Furthermore, the repeater node 103 further comprises a time counter 406, preferably integrated in the controller 402, and configured for flipping the switch 405, by electrically connecting the sensors 401 to the electric power source 404, in order to turn them on after a predetermined time has elapsed.

The repeater node 103 could further comprise a local memory (not represented) for saving at least one portion of the data relating to the environment monitoring, as a backup system in case of transmission malfunction.

The controller 402 thus manages the reception and transmission part, the reading of the ADCs which the sensors 401 are connected to, and the power supply in the‘sleep’ and Svork’ phases by flipping the switch 405, in order to reduce the energy consumption to a minimum. The electric consumption of the time counter 406 is much reduced, thus ensuring a limited energy absorption in the‘sleep’ phase.

The wireless communication interface 403 represents both the vehicle of information generated by the repeater node 103 and thus transmitted to the central node 101 (in a Svork’ phase), and the vehicle of the information generated by other sensor nodes 102, received by the repeater node 103 and thus transmitted to the central node 101 (in a Svait’ phase).

Therefore, the wireless communication interface 403 is continuously supplied and not subjected to periodic turning off and on by the switch 405. Instead, the sensors 401 are turned off in the‘sleep’ phase, thus further reducing the consumption of electric power.

Figure 5 shows a communication protocol of a sensor node 102 according to the present invention.

In a first step 501 , a wake-up message S 1 is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message Cl for turning on the at least one sensor 201 , is monitored.

If timeout is verified and the maximum number of attempts“N retry max” is reached, the sensor node 102 goes to‘sleep’ phase.

In a second step 502, an acknowledgement message S2 is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message C2 for initiated reading from the at least one sensor 201 , is monitored.

Again, if timeout is verified and the maximum number of attempts“N retry max” is reached, the sensor node 102 goes to‘sleep’ phase.

In a third step 503, a message S3 which carries both acknowledgment and data read from the at least one sensor 201 is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message C3 for turning off the at least one sensor 201 , is monitored.

In a fourth step 504, an acknowledgement message S4 is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message C4 for turning off the at least one sensor 201 , is monitored.

If the message C4 is received, the sensor node 102 goes to‘sleep’ phase having completed the reading.

Figure 6 shows a communication protocol of a repeater node 103 according to the present invention.

In a first step 601 , when a timer for the measuring phase expires, a wake- up message SI is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message C 1 for turning on the at least one second sensor 401 , is monitored.

If timeout is verified and the maximum number of attempts“N retry max” is reached, the repeater node 103 ends the measuring phase.

In a second step 602, an acknowledgement message S2 is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message C2 for initiated reading from the at least one second sensor 401 , is monitored.

If timeout is verified and the maximum number of attempts“N retry max” is reached, the at least one second sensor 401 is turned off and the repeater node 103 ends the measuring phase.

In a third step 603, a message S3 which carries both acknowledgment and data read from of the at least one second sensor 401 is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message C3 for turning off the at least one second sensor 401 , is monitored.

Again, if timeout is verified and the maximum number of attempts“N retry max” is reached, the at least one second sensor 401 is turned off and the repeater node 103 ends the measuring phase.

In a fourth step 604, an acknowledgement message S4 is sent. A timer T_ack is initialized and, within a timeout period, the reception of an acknowledgment message C4 for turning off the at least one second sensor 401 , is monitored.

If the message C4 is received, the repeater node 103 ends the measuring phase.

Again, if timeout is verified and the maximum number of attempts“N retry max” is reached, the repeater node 103 ends the measuring phase.

The general operation of the environment monitoring system 100 according to the present invention can be summarized as follows.

The sensor node 102 “wakes up” after a predetermined time, preferably settable by the user in the installation phase. In the phase called Svork’ phase, which lasts a few milliseconds, the sensor node 102 activates through the switch 205 own radio module 203 and the sensors 201 , performs the measurement, calculation and saving of the data; the sensor node 102 thus sends the data packets to the repeater node 103 or to the central node 101. Once the sensor node 102 has received the acknowledgement message and the possible command message, with possible further parameters supplied by the user through web-App, it deactivates the switch 205, in order to deactivate own radio module 203 and the sensors 201 , and switches to the ‘sleep’ phase until the predetermined period has once again elapsed.

In the‘sleep’ phase, the sensor node 102 will have an average consumption of less than 1 mA, considerably reducing the consumption of the non- rechargeable batteries 204: therefore, they will only be stressed during the Svork’ phase.

The repeater node 103 is present in case of considerable distance between a sensor node 102 and the central node 101 and has the task of “relaunching” any data received from a sensor node 102 to the reference central node 101 , and vice versa; furthermore, the repeater node 103 can measure own data and send them. Although the repeater node 103 is equipped with a switch 405, which activates or deactivates the sensor 401 power supply, the radio module 403 remains turned on and is supplied by a preferably rechargeable source 404, such as a battery system associated with a solar panel.

As soon as the central node 101 has received data from a sensor node 102 or from a repeater node 103 belonging to own network, it connects with the server 1000 for communicating said datum and for retrieving the configuration parameters of the whole network, if there were variations; said configuration parameters (relating to each node) will be communicated in reply to each notice by the involved nodes. The central node 101 is connected to the electric network (through a DC power supply between + 7V and + 12V) since it is always in receipt (with active radio module 303) and requires more power in the GSM connection phase.

Industrial applicability

In the environment monitoring system 100 according to the present invention, the sensor nodes 102 are in a number far greater than the central nodes 101 and the possible repeater nodes 103.

Since the‘low-power’ mode is particularly effective for the sensor nodes 102, the energy optimization implemented by the present invention is scalable for the cost and consumption reduction.

Considering the disclosure herein reported, the skilled person will be able to conceive further changes and variants, in order to meet contingent and specific needs.

In particular, the exemplifying embodiment of an environment monitoring system provides sensors for measuring soil humidity, air humidity, air temperature, for cooperating with a watering system.

However, other types of sensors could optionally be adopted, additionally or alternatively to the above cited ones.

Furthermore, appropriate actuators could be adapted, such as hydraulic valves in particular solenoid valves, integrated in the sensor nodes.

The embodiments herein disclosed must be intended as non-limiting examples of the invention.

Claims

1. Environment monitoring system (100) comprising: a central node (101) and a plurality of sensor nodes (102) configured for being connected to said central node (101), wherein said central node (101) comprises: a first wireless communication interface (303) and a first controller (302) configured for receiving data through said first wireless communication interface (303) and for transmitting said data to a database (1000) ; and wherein each of said sensor nodes (102) respectively comprises: at least one sensor (201) for measuring at least one environment parameter, a second controller (202) connected to said at least one sensor (201) for obtaining data relating to said at least one environment parameter, a second wireless communication interface (203) connected to said second controller (202) and configured for transmitting said data to said central node (101), at least one electric battery (204) for supplying said at least one sensor (201), said second controller (202) and said second wireless communication interface (203), characterized in that each of said sensor nodes (102) further comprises: at least one switch (205) configured for turning off said at least one sensor (201) and said second wireless communication interface (203), electrically disconnecting them from said at least one electric battery (204), and a time counter (206) configured for flipping said at least one switch (205), electrically connecting said at least one sensor (201) and said second wireless communication interface (203) to said at least one electric battery (204), to turn them on after a predetermined time has elapsed, and further for obtaining said data and transmitting said data to said central node (101) and in that said first controller (302) is further configured for generating an acknowledgement message upon receipt of said data, said first wireless communication interface (303) being configured for transmitting said acknowledgement message to a respective one of said sensor nodes (102), said second controller (202) being further configured for further flipping said switch (205), to turn off said at least one sensor (201) and said second wireless communication interface (203), upon receipt of said acknowledgement message.

2. Environment monitoring system (100) according to claim 1 , wherein said first controller (302) is further configured for comparing respective reception instants of said data from different sensor nodes (102) of said plurality of sensor nodes (102) and is further configured for generating a command message transmitted together with said acknowledgement message, said second controller (202) being further configured for modifying said predetermined time in reply to said command message.

3. Environment monitoring system (100) according to any one of claims 1 to 2, wherein said time counter (206) is integrated in said second controller (202), said battery (204) being configured for continuously supplying said second controller (202).

4. Environment monitoring system (100) according to any one of claims 1 to 3, wherein said central node (101) and said sensor node (102) are configured for: sending a wake-up message (SI); within a timeout period, monitoring the reception of an acknowledgment message (Cl) for turning on the at least one sensor (201); sending an acknowledgement message (S2); within a timeout period, monitoring the reception of an acknowledgment message (C2) for initiated reading from the at least one sensor (201); sending a message (S3) which carries both acknowledgment and data read from the at least one sensor (201); within a timeout period, monitoring the reception of an acknowledgment message (C3) for turning off the at least one sensor (201); sending an acknowledgement message (S4); within a timeout period, monitoring the reception of an acknowledgment message (C4) for turning off the at least one sensor (201); wherein the sensor node (102) goes to a sleep phase having completed the reading.

5. Environment monitoring system (100) according to claim 4, wherein said central node (101) and said sensor node (102) are further configured for: if timeout is verified and a maximum number of attempts is reached, said sensor node (102) goes to the sleep phase.

6. Environment monitoring system (100) according to any one of claims 1 to 5, further comprising at least one repeater node (103) comprising: a third controller (402) and a third wireless communication interface (403) connected to said third controller (402) and configured for receiving data from at least one of said sensor nodes (102) and retransmitting said data to said central node (101) or to a further repeater node (103).

7. Environment monitoring system (100) according to claim 6, wherein said repeater node (103) further comprises at least one electric power source (404) for continuously supplying said third controller (402) and of said third wireless communication interface (403), said electric power source (404) preferably comprising a second battery or an electric cabled connection.

8. Environment monitoring system (100) according to claim 7, wherein said repeater node (103) further comprises at least one second sensor (401) for measuring at least one environment parameter, said third controller

(402) being connected to said at least one second sensor (401) for obtaining second data relating to said at least one environment parameter, said electric power source (404) being further configured for supplying said at least one second sensor (401), said third wireless communication interface

(403) being further configured for transmitting said second data to said central node (101) or to a further repeater node (103).

9. Environment monitoring system (100) according to claim 8, wherein said repeater node (103) further comprises at least one second switch (405) configured for turning off said at least one second sensor (401), electrically disconnecting it from said electric power source (404), and a second time counter (406) configured for flipping said at least one second switch (405), electrically connecting said at least one second sensor (401) to said at least one electric power source (404), for turning it on after a second predetermined time has elapsed.

10. Environment monitoring system (100) according to any one of claims 6 to 9, wherein said central node (101) and said sensor node (102) and said repeater node (103) are further configured for: when a timer for a measuring phase expires, sending a wake-up message (SI); within a timeout period, monitoring the reception of an acknowledgment message (Cl) for turning on the at least one second sensor (401); sending an acknowledgement message (S2); within a timeout period, monitoring the reception of an acknowledgment message (C2) for initiated reading from the at least one second sensor (401); sending a message (S3) which carries both acknowledgment and data read from the at least one second sensor (401); within a timeout period, monitoring the reception of an acknowledgment message (C3) for turning off the at least one second sensor (401); sending an acknowledgement message (S4) within a timeout period, monitoring the reception of an acknowledgment message (C4) for turning off the at least one second sensor (401); wherein, if the acknowledgement message (C4) is received, the repeater node (103) ends a measuring phase.

1 1. Environment monitoring system (100) according to claim 10, wherein said central node (101) and said sensor node ( 102) and said repeater node (103) are further configured for: if timeout is verified and a maximum number of attempts is reached, the repeater node (103) ends the measuring phase, and preferably the at least one second sensor (401) is turned off.

12. Environment monitoring system ( 100) according to any one of claims 1 to 1 1 , wherein said at least one environment parameter comprises one or more of the following: soil humidity, air humidity, air temperature, said environment monitoring system (100) being in particular configured for cooperating with a watering system.

13. Environment monitoring system (100) according to any one of claims 1 to 12, wherein said central node (101) further comprises a network communication device (307), preferably of a cellular network, configured for transmitting from remote said data to said database ( 1000) .

14. Watering system, comprising means for selectively distributing water into an environment; characterized in that it comprises an environment monitoring system (100) according to any one of claims 1 to 13.

15. Watering system according to claim 14, wherein said water is distributed depending on measurements of said environment monitoring system (100), wherein a remote database (1000) preferably processes said measurements .