Patent Description:
Environmental sensors are used in agricultural or horticultural settings in order to monitor growing conditions. Known environmental sensors include e.g. temperature, humidity and soil moisture sensors.

Typical systems use individual sensors dedicated to sensing a single environmental condition. Existing sensors also suffer from difficulty in use and/or installation, with some sensors having high power requirements and requiring physical connection to a mains power source. Some sensors are arranged for wireless communication of sensed data. However, these sensors may have limited range and communication of data in a large area typically requires the use of separate communication repeaters.

Existing individual sensors may be mounted in louvred housings in an attempt to protect the sensors while allowing accurate measurement of conditions outside the housing. However, accuracy remains problematic.

Existing sensor units are expensive and fail to provide accurate or reliable data. Existing sensor units are difficult to install and/or use and require too much power during operation.

It is an object of the invention to provide improvements in environmental sensor arrangements and/or systems and/or methods and/or in associated agricultural or horticultural systems, or at least to provide the public with a useful choice.

<CIT> relates to a sensor apparatus for an agricultural greenhouse which can simply calibrate a CO<NUM> sensor. The apparatus has a main casing and a sub casing suspended from the bottom of the main casing. An internal space of the main casing is separated into an upper chamber (including a control part which processes a sensor signal) and a lower chamber which has a temperature/humidity sensor and a fan. A CO<NUM> sensor, a power source and a CPU are housed in the sub casing. A pair of air intake ports and an outlet port are disposed respectively at an opposing position of a wall closer to the lower chamber and a bottom wall of the chamber, and a fan is arranged in this area.

<CIT> relates to a field microclimate automatic observation station with multi-data collection, multi-mode output of results and manpower saving. The field microclimate automatic observation station includes a data acquisition unit which comprises a wind direction sensor, a wind speed sensor, a rainfall collection barrel, and a rainfall sensor.

According to the claimed invention, there is provided an agricultural or horticultural environment multi-sensor unit as set out in claim <NUM>.

Optional features of the claimed invention are set out in the dependent claims.

The invention will be described by way of example only, with reference to the accompanying drawings, in which:.

For the purposes of this specification, the term 'about' or 'approximately' and grammatical variations thereof mean a quantity, level, degree, value, number, frequency, percentage, dimension, size, amount, weight or length that varies by as much as <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>% to a reference quantity, level, degree, value, number, frequency, percentage, dimension, size, amount, weight or length.

The term 'substantially' or grammatical variations thereof refers to at least about <NUM>%, for example <NUM>%, <NUM>%, <NUM>% or <NUM>%.

The term 'comprise' and grammatical variations thereof shall have an inclusive meaning - i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements.

The Applicant's sensor units, systems and sensing methods may be particularly suited to application in controlled agricultural or horticultural environments. Such controlled environments may include, for example, greenhouses, indoor grow rooms, indoor farms etc..

The sensor arrangements may provide a detailed view of environmental conditions in the controlled environment.

The sensor units may include any combination of desired environmental sensors which includes at least an incident light sensor and a temperature sensor. The integration of a plurality of sensors in a single housing provides convenient gathering of multiple sensor data.

Further, the sensor units may be arranged to communicate with each other and/or with a communications gateway, in order to provide robust and convenient communication of data from the sensors. In some embodiments a mesh network may be implemented between the sensor units and the gateway. This may be achieved using any suitable wireless communications protocol. Bluetooth may be used, which may provide easy configuration using a cellphone and the range necessary to operate in a large-scale growing environment. The Bluetooth <NUM> protocol allows a low power usage but can still penetrate biomass. However other wireless communications technologies, such as LoRa may be used if greater range is required.

Data may be gathered and provided to a cloud-based service which provides rich visualisations and insights to the user. The sensor units may be arranged to automatically act as repeaters within the network when provided with an external power connection.

The sensor units may be arranged and/or controlled in order to limit or prevent undesirable interactions between sensors, which could impact on data accuracy. The sensor units may operate with relatively low power requirements and may be either battery powered or may receive power from an external source (e.g. mains power). Measurements of many types are therefore provided by one low powered wireless device. The measurements taken may include one or more of: temperature, relative humidity, solar irradiance, photosynthetically active radiation, air pressure, CO<NUM> concentration, and soil moisture. Other desired measurements may be added if required.

Where the sensor units include one or more incident light sensors, a lens arrangement may be used in order to pass incident light to the light sensors and in some embodiments to reduce the dependency of the sensor output on the light's angle of incidence. Further, one or more orientation sensors may be included to provide orientation data for the sensor unit. The orientation data may be used in correcting any sensor data based on known variations in the sensor data with orientation. This may be particularly useful in correcting data from the incident light sensor or sensors.

The sensors may include a carbon dioxide sensor. This sensor may be arranged to sense a concentration of carbon dioxide in the air. Infrared gas sensors may be suitable. Nondispersive infrared (NDIR) CO<NUM> sensors may be suitable. For example, a sensor from the CozIR®-LP CO<NUM> sensor range may be suitable in some embodiments.

The sensors include one or more incident light sensors. Any suitable ambient light sensor or other photodetector may be used. Photodiode sensors may be suitable. The incident light sensors may be sensitive across a desired wavelength range. The one or more light sensors may include either or both of: a solar irradiance sensor and a photosynthetically active radiation sensor. Photosynthetically active radiation is radiation used by plants in photosynthesis (usually considered to be in the wavelength range <NUM> to <NUM>). In some embodiments OSRAM SFH2200 and/or SFH2240 sensors may be suitable, for example.

An optical arrangement arranged to pass incident light to the one or more incident light sensors may be included. This may be provided at the top of the sensor unit. In some embodiments the optical arrangement may include a lens structure arranged to gather light from a broad range of incidence angles and pass it to the sensor(s). This ensures that regardless of the incident angle (which may vary e.g. due to movement of the sun) the measurement is accurate. This may be further improved by ensuring that the sensor unit is level. One or more integrated orientation sensors (e.g. accelerometer and gyroscope) may be used to provide orientation information during installation, assisting the installer to level the sensor unit. The orientation sensors may also be used to monitor the angle of the product so that levelling errors can be detected.

In addition, this lens component may also provide a light pipe path from several LED lights inside the device to the outer surface of the housing to provide user feedback for installation, configuration and/or use. In some embodiments the LEDs may provide feedback during installation and then be turned off to save power. For example, in one embodiment sufficient LEDs may be provided to allow feedback to be provided that: the sensor unit is running an installation test, the test was successful, communication failure (e.g. out of range), sensor failed test (preferably with a separate indication for each sensor within the sensor unit. Any combination of LED colours, solid light, flashing light, number of LEDs etc may be used to display this information.

The sensors may include a humidity sensor. The sensor include a temperature sensor. A single sensor measuring relative humidity and temperature may be used. For example, the Sensirion SHT35 relative humidity and temperature sensor may be suitable in some embodiments.

The sensors may include a barometric pressure sensor. For example, the Bosch BMP280 digital barometer may be suitable in some embodiments.

The sensors may include one or more position sensors. For example, any suitable GPS sensor may be used, such as the Ubox GPS-SAM-M8Q. Other positioning sensors may be used, e.g. based on local positioning systems. Further, in some embodiments users may enter sensor unit positions rather than relying on the use of a position sensor.

The sensors may include one or more orientation sensors, including e.g. <NUM>-axis accelerometers.

The sensors are mounted within a housing. A louvred housing is used, providing airflow through the housing (and to the sensors) without the need for powered flow devices such as fans. The louvred design decouples the energy incident onto each louvre from the other louvres, making it difficult for thermal energy to travel to the inner areas of the sensor unit. This may be particularly advantageous in accurate measurement of temperature. Further, in some embodiments the temperature sensor may be protected from the influence of solar radiation which can skew the measurement upwards. This may be achieved by the louvred housing, and in addition a physical separation between the temperature sensor and at least some of the other sensors may be provided.

Combining the measurement of solar radiance and temperature into the same device poses a challenge as the light sensors must be exposed to the sun, causing local heating. The temperature sensors are separated from the incident light sensors in order to provide accurate measurement. In particular, incident light sensor(s) are located at the top of the sensor unit, with the temperature sensor located lower in the sensor unit (e.g. near the middle or the bottom of the sensor unit), isolating it from the effects of light heating the top of the sensor unit. The louvred design decouples the energy incident onto each plate from the other plates making it difficult for thermal energy to travel to the inner areas of the device. In addition, this structure promotes natural convection through the device allowing airflow while providing protection from water and sunlight.

The management of air flow through the sensor unit without the requirement of a separate fan unit allows the sensor unit to receive the required air across the sensors and reduces battery consumption.

In some embodiments a pair of C cell batteries are expected to last up to <NUM> months.

External or auxiliary sensors may be connected to the sensor unit. For example, an external soil moisture sensor may be connected to the sensor unit. External sensors may communicate with the sensor unit via a wired connection, e.g. connected to an auxiliary sensor port. Alternatively, external sensors may communicate with the sensor unit over a wireless connection. External sensors may contain their own battery or external power connection, or may draw power from the sensor unit.

High quality and quantity of sensor data can be communicated via the network and uploaded to remote storage. The sensor unit can be driven by an App or any other desired interface to give one or more indications of the microclimate/environment of the greenhouse or other growing environment. Further, the data may be stored for monitoring the environment history and/or for integration into control systems. Visualisations and insights may be provided or displayed to the user. User prompts or alarms may be issued via any suitable output or display device should any of the environmental conditions satisfy an alert condition (e.g. pass a threshold, fall outside an allowed range etc). The prompts or alarms may be user-configurable via an app or other interface.

Still further, the sensor data may be used in a broader control system, in which environmental conditions are controlled in accordance with the sensor data. Environmental conditions that may be controlled include: temperature, relative humidity, ventilation, solar energy, soil moisture and the like. Ventilation systems, watering systems, heating systems, cooling systems, shading systems, lighting systems etc may all be controlled based on the sensor data. Desired values or ranges for the environmental conditions may be set by a user, e.g. via an app or other suitable interface.

The sensors within the sensor unit may be controlled to gather data at staggered times, in order to reduce the peak power requirement of the sensor unit. In particular, the carbon dioxide sensor may be operated during its own time interval as its power consumption is relatively high.

The sensor unit may be mounted in any suitable manner, and suitable fitting may be provided on the housing for pole mounting, hanging etc..

The above described apparatus, methods and uses are now described by reference to specific examples.

<FIG> show a sensor unit according to one embodiment. The sensor unit <NUM> includes a louvred housing <NUM> in which a plurality of internal environmental sensors are mounted. In general, the plurality of environmental sensors may be mounted in one or more locations within the housing <NUM>. In the embodiment shown in <FIG>, a first sensor assembly <NUM> is mounted near the top of the housing <NUM> while a second sensor assembly <NUM> is mounted lower in the housing <NUM>, e.g. near the middle or bottom of the housing <NUM>. The second sensor assembly <NUM> is therefore spaced from the first sensor assembly <NUM>.

In this embodiment, the first, upper sensor assembly <NUM> includes at least an incident light sensor, while the second lower sensor assembly <NUM> includes at least a temperature sensor. Other sensors may be located on either the first or second sensor assembly (<NUM>, <NUM>), or may be mounted separately or in a further sensor assembly. In the embodiment shown the CO<NUM>, incident light, GPS and orientation sensors are included in the first sensor assembly <NUM>, while relative humidity / temperature and barometric pressure sensors are included in the second sensor assembly <NUM>.

<FIG> show circuit board assemblies that may be used in a sensor unit such as that of <FIG>. <FIG> are top and bottom views of a first sensor assembly <NUM>. <FIG> are top and bottom views of a second sensor assembly <NUM>. <FIG> are top and bottom views of a further sensor unit assembly.

A processor mounted to the first circuit board at location <NUM> may communicate with the network via a wireless communications interface and gather all sensor data.

Power may be provided via battery terminals <NUM>, <NUM> or through external power connector <NUM> located on the bottom board.

Sensor data provided by numerous sensor, which may include a CO<NUM> sensor connected to the top board using a connector <NUM>, solar irradiation sensor mounted to the top board located at <NUM>, photosynthetically active radiation sensor mounted to the top board located at <NUM>, orientation sensor mounted to the top board located at <NUM>, GPS sensor mounted to the top board located at <NUM>, temperature and relative humidity sensor mounted to the middle board located at <NUM> and barometric pressure sensor mounted to the middle board located at <NUM>. A connector <NUM> may be mounted to the bottom board allows for wired connection of an external auxiliary sensor or external auxiliary sensor port.

The housing <NUM> includes a number of louvres <NUM>, with spaces <NUM> between, allowing air to flow through the interior of the housing <NUM> and over at least those sensors requiring airflow. In the embodiment shown, airflow is provided to the CO<NUM> sensor on the first sensor assembly <NUM> as well as to the sensors on the second sensor assembly <NUM>. This provides acceptable airflow to temperature, relative humidity, air pressure and CO<NUM> concentration sensors located within the housing <NUM>, without the need for powered flow devices such as fans.

As shown in <FIG> and <FIG>, an optical element <NUM> may be provided in a top surface of the housing <NUM>, allowing incident light to pass through the housing <NUM> for sensing by the incident light sensor, as will be described in detail below. <FIG> also shows formations <NUM> suitable for hanging the sensor unit from a support structure.

<FIG> is an exploded view of an upper sensor assembly. A circuit board <NUM> may carry suitable circuitry for power and communications connections. Incident light sensors <NUM>, <NUM> may be mounted to an upper surface of the circuit board <NUM>. A CO<NUM> sensor <NUM> may be mounted to a bottom surface of the circuit board <NUM>. An upper component may include one or more optical elements <NUM> (such as optical windows, lenses, filters, mirrors etc that are arranged to allow incident light to fall onto the incident light sensors <NUM>, <NUM>. The one or more optical elements <NUM> may disperse incident light such that dispersed incident light falls on the incident light sensors <NUM>, <NUM>. The one or more optical elements <NUM> may direct incident light onto the incident light sensors <NUM>, <NUM>. In some embodiments at least one of the one or more optical elements <NUM> may be shaped or arranged to reduce a dependence of the incident light reading on the incidence angle of the incident light. <FIG> is a schematic diagram illustrating some components of the sensor unit <NUM>. A processor <NUM> communicates with the network via a wireless communications interface <NUM>. A battery <NUM> and/or external power connector <NUM> provide power to the various components of the sensor unit <NUM>. The unit <NUM> includes a plurality of environmental sensors, which provide data to the processor <NUM> and which may include a CO<NUM> sensor <NUM>, solar irradiation sensor <NUM>, photosynthetically active radiation sensor <NUM>, orientation sensor <NUM>, temperature and relative humidity sensor <NUM>, barometric pressure sensor <NUM> and GPS sensor <NUM>. A port <NUM> may allow for wired connection of an external auxiliary sensor. Other sensors may be included.

A reset / test switch <NUM> (<FIG>) may also be included to allow a user to reset the sensor unit <NUM> and/or to run a test procedure.

<FIG> is a schematic diagram illustrating a sensor system <NUM> incorporating a plurality of sensor units <NUM>, <NUM>, <NUM>, <NUM> distributed in a controlled agricultural or horticultural environment <NUM>. In general, any suitable number of sensor units may be used. When installed and powered, the sensor units <NUM>, <NUM>, <NUM>, <NUM> may automatically form a mesh network via wireless communications links <NUM> with each other. In some embodiments all sensor units <NUM>, <NUM>, <NUM>, <NUM> may act as full nodes / repeaters in the network. In other embodiments only sensor units that are connected to external power sources will automatically act as repeaters. The mesh network may connect via a further wireless link <NUM> with a gateway device <NUM>.

In some embodiments the gateway device <NUM> may also be part of the mesh network and/or may be incorporated into or connected by a wired connection to one of the sensor units. The gateway may connect to one or more local processors <NUM>, databases <NUM> and/or to the cloud <NUM>. A user may interact with the system through local processor <NUM>, or may connect to the gateway <NUM>, local processor <NUM>, database <NUM> or cloud <NUM> using any suitable user device, including smartphones, tablets, computers or other suitable devices. Sensor data may be stored in the database <NUM>, cloud <NUM> or other suitable storage.

<FIG> is a schematic diagram showing how data may be transmitted through the network. A first sensor unit <NUM> transmits first sensor data to a second sensor unit <NUM>. The second sensor data repeats the first sensor data and send second sensor data to a third sensor unit <NUM>. The third sensor unit <NUM> repeats the first and second sensor data and sends third sensor data to the gateway device <NUM>.

The sensors may capture data continuously or periodically. In one embodiment the sensors may measure continuously but data may be transmitted from the sensor unit periodically, e.g. every <NUM> to <NUM> minutes.

Any suitable array of sensor units may be provided within the growing space, and this may depend on the communication range, the desired spatial density of sensor data and the density of any foliage that may interfere with communication. In one embodiment Bluetooth <NUM> long range communications may provide a range of several hundred meters with direct line of sight, but around <NUM> meters through foliage. In some embodiments the spacing between sensor units may therefore be <NUM> meters or less. The sensor unit array may be easily scaled for the size of a particular growing environment. Further sensor units may be added with automatic connection to the network and without the need for any pairing or manual connection process.

Claim 1:
An agricultural or horticultural environment multi-sensor unit (<NUM>), without a separate fan unit for the management of air flow through the multi-sensor unit (<NUM>), the multi-sensor unit including:
a plurality of environmental sensors; and
a louvred housing (<NUM>) in which the plurality of environmental sensors are mounted;
wherein the environmental sensors include at least:
an incident light sensor (<NUM>, <NUM>); and
a temperature sensor (<NUM>) spaced from the incident light sensor (<NUM>, <NUM>) and positioned such that air may flow freely through the louvred housing (<NUM>) and over the temperature sensor (<NUM>);
wherein airflow through the multi-sensor unit (<NUM>) is allowed by the louvred housing (<NUM>) to provide accurate sensor measurements without the use of powered fans,
characterised by
a first sensor assembly (<NUM>) mounted near the top of the housing (<NUM>), and
a second sensor assembly (<NUM>) spaced from the first sensor assembly (<NUM>) and mounted lower in the housing (<NUM>), in which the first sensor assembly (<NUM>) includes at least the incident light sensor (<NUM>, <NUM>) positioned near a top surface of the housing (<NUM>), which is configured to allow light to enter the housing (<NUM>) to fall on the incident light sensor (<NUM>, <NUM>), and the second sensor assembly (<NUM>) includes at least the temperature sensor (<NUM>).