The disclosure relates generally to the field of agriculture, and, in particular, to irrigation control in a controlled agricultural environment.
The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.
During the twentieth century, agriculture slowly began to evolve from a conservative industry to a fast-moving high-tech industry in order to keep up with world food shortages, climate change, and societal changes. Farming began to move away from manually-implemented agricultural techniques toward computer-implemented technologies. Conventionally, farmers only have one growing season to produce the crops that would determine their revenue and food production for the entire year. However, this is changing. With indoor growing as an option, and with better access to data processing technologies and other advanced techniques, the science of agriculture has become more agile. It is adapting and learning as new data is collected and insights are generated.
Advancements in technology are making it feasible to control the effects of nature with the advent of “controlled indoor agriculture,” otherwise known as “controlled environment agriculture.” Improved efficiencies in space utilization and lighting, a better understanding of hydroponics, aeroponics, and crop cycles, and advancements in environmental control systems have allowed humans to better recreate environments conducive for agriculture crop growth with the goals of greater harvest weight yield per square foot, better nutrition and lower cost.
US Patent Publication Nos. 2018/0014485 and 2018/0014486, both assigned to the assignee of the present disclosure and incorporated by reference in their entirety herein, describe environmentally controlled vertical farming systems. The vertical farming structure (e.g., a vertical column) may be moved about an automated conveyance system in an open or closed-loop fashion, exposed to precision-controlled lighting, airflow and humidity, with ideal nutritional support.
For an indoor farm, ideally optimum growth conditions are determined for the plants and the HVAC system is adjusted to obtain those optimum growth conditions. Of course, for a particular crop the optimum growth conditions are usually those desired for an indoor farm. However, the plant media (e.g., soil) can dry out due to evaporation and transpiration, which vary depending on plant age and other conditions in the grow room. It is desired to maintain desired moisture levels in the media and avoid dryout.
According to embodiments of the disclosure, systems, methods, and computer-readable media storing instructions are operable to control irrigation of media of plants in a grow space in response to a measurement of condensed water from air in the grow space. According to embodiments of the disclosure, the grow space is a controlled agricultural environment.
According to embodiments of the disclosure, controlling irrigation comprises increasing irrigation in response to a relationship between a volume based on the measurement of the condensed water and a threshold volume. According to embodiments of the disclosure, controlling irrigation comprises setting irrigation volume in response to a volume based on the measurement of the condensed water.
According to embodiments of the disclosure, a dehumidifier condenses water from air from the grow space to produce the condensed water. According to embodiments of the disclosure, the condensed water results from evaporation and transpiration in the grow space. According to embodiments of the disclosure, a water volume measurement device measures the condensed water. According to embodiments of the disclosure, the water volume measurement device comprises a flow meter, a flow totalizer, a tank with a level sensor, or supply and return air temperature and humidity sensors.
The present description is made with reference to the accompanying drawings, in which various example embodiments are shown. However, many different example embodiments may be used, and thus the description should not be construed as limited to the example embodiments set forth herein. Rather, these example embodiments are provided so that this disclosure will be thorough and complete. Various modifications to the exemplary embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the disclosure. Thus, this disclosure is not intended to be limited to the disclosed embodiments, but is to be accorded the widest scope consistent with the claims and the principles and features disclosed herein.
Exemplary Indoor Agricultural System
The following describes a vertical farm production system configured for high density growth and crop yield. Although embodiments of the disclosure will primarily be described in the context of a vertical farm in which plants are grown in towers, those skilled in the art will recognize that the principles described herein are not limited to a vertical farm or the use of grow towers, but rather apply to plants grown in any structural arrangement.
The system 10 may also include conveyance systems for moving the grow towers in a circuit throughout the crop's growth cycle, the circuit comprising a staging area configured to load the grow towers into and out of the vertical tower conveyance mechanism 200. The central processing system 30 may include one or more conveyance mechanisms for directing grow towers to stations in the central processing system 30, e.g., stations for loading plant plugs into, and harvesting crops from, the grow towers. The vertical tower conveyance system 200 is configured to support and translate one or more grow towers 50 along grow lines 202. According to embodiments of the disclosure, the grow towers 50 hang from the grow lines 202.
Each grow tower 50 is configured to contain plant growth media that supports a root structure of at least one crop plant growing therein. Each grow tower 50 is also configured to releasably attach to a grow line 202 in a vertical orientation and move along the grow line 202 during a growth phase. Together, the vertical tower conveyance mechanism 200 and the central processing system 30 (including associated conveyance mechanisms) can be arranged in a production circuit under control of one or more computing systems.
The growth environment 20 may include light emitting sources positioned at various locations between and along the grow lines 202 of the vertical tower conveyance system 200. The light emitting sources can be positioned laterally relative to the grow towers 50 in the grow line 202 and configured to emit light toward the lateral faces of the grow towers 50, which include openings from which crops grow. The light emitting sources may be incorporated into a water-cooled, LED lighting system as described in U.S. Publication No. 2017/0146226A1, the disclosure of which is incorporated by reference in its entirety herein. In such an embodiment, the LED lights may be arranged in a bar-like structure. The bar-like structure may be placed in a vertical orientation to emit light laterally to substantially the entire length of adjacent grow towers 50. Multiple light bar structures may be arranged in the growth environment 20 along and between the grow lines 202. Other lighting systems and configurations may be employed. For example, the light bars may be arranged horizontally between grow lines 202.
The growth environment 20 may also include a nutrient supply system configured to supply an aqueous crop nutrient solution to the crops as they translate through the growth chamber 20. The nutrient supply system may apply aqueous crop nutrient solution to the top of the grow towers 50. Gravity may cause the solution travel down the vertically-oriented grow tower 50 and through the length thereof to supply solution to the crops disposed along the length of the grow tower 50. The growth environment 20 may also include an airflow source that is configured to, when a tower is mounted to a grow line 202, direct airflow in the lateral growth direction of growth and through an under-canopy of the growing plant, so as to disturb the boundary layer of the under-canopy of the growing plant. In other implementations, airflow may come from the top of the canopy or orthogonal to the direction of plant growth. The growth environment 20 may also include a control system, and associated sensors, for regulating at least one growing condition, such as air temperature, airflow speed, relative air humidity, and ambient carbon dioxide gas content. The control system may for example include such sub-systems as HVAC units, chillers, fans and associated ducting and air handling equipment. Grow towers 50 may have identifying attributes (such as bar codes or RFID tags). The controlled environment agriculture system 10 may include corresponding sensors and programming logic for tracking the grow towers 50 during various stages of the farm production cycle or for controlling one or more conditions of the growth environment. The operation of control system and the length of time towers remain in the growth environment can vary considerably depending on a variety of factors, such as crop type and other factors.
The grow towers 50 with newly transplanted crops or seedlings are transferred from the central processing system 30 into the vertical tower conveyance system 200. Vertical tower conveyance system 200 moves the grow towers 50 along respective grow lines 202 in growth environment 20 in a controlled fashion. Crops disposed in grow towers 50 are exposed to the controlled conditions of the growth environment (e.g., light, temperature, humidity, air flow, aqueous nutrient supply, etc.). The control system is capable of automated adjustments to optimize growing conditions within the growth chamber 20 and make continuous improvements to various attributes, such as crop yields, visual appeal and nutrient content. In addition, US Patent Publication Nos. 2018/0014485 and 2018/0014486, incorporated by reference herein, describe application of machine learning and other operations to optimize grow conditions in a vertical farming system. In some implementations, environmental condition sensors may be disposed on grow towers 50 or at various locations in the growth environment 20. When crops are ready for harvesting, grow towers 50 with crops to be harvested are transferred from the vertical tower conveyance system 200 to the central processing system 30 for harvesting and other processing operations.
Central processing system 30 may include processing stations directed to injecting seedlings into towers 50, harvesting crops from towers 50, and cleaning towers 50 that have been harvested. Central processing system 30 may also include conveyance mechanisms that move towers 50 between such processing stations. For example, as
Controlled environment agriculture system 10 may also include one or more conveyance mechanisms for transferring grow towers 50 between growth environment 20 and central processing system 30. In the implementation shown, the stations of central processing system 30 operate on grow towers 50 in a horizontal orientation. In one implementation, an automated pickup (loading) station 43, and associated control logic, may be operative to releasably grasp a horizontal tower from a loading location, rotate the tower to a vertical orientation and attach the tower to a transfer station for insertion into a selected grow line 202 of the growth environment 20. On the other end of growth environment 20, automated laydown (unloading) station 41, and associated control logic, may be operative to releasably grasp and move a vertically oriented grow tower 50 from a buffer location, rotate the grow tower 50 to a horizontal orientation and place it on a conveyance system for loading into harvester station 32. In some implementations, if a grow tower 50 is rejected due to quality control concerns, the conveyance system may bypass the harvester station 32 and carry the grow tower to washing station 34 (or some other station). The automated laydown and pickup stations 41 and 43 may each comprise a six-degrees of freedom robotic arm, such as a FANUC robot. The stations 41 and 43 may also include end effectors for releasably grasping grow towers 50 at opposing ends.
Growth environment 20 may also include automated loading and unloading mechanisms for inserting grow towers 50 into selected grow lines 202 and unloading grow towers 50 from the grow lines 202. According to embodiments of the disclosure, a load transfer conveyance mechanism 47 may include a powered and free conveyor system that conveys carriages each loaded with a grow tower 50 from the automated pickup station 43 to a selected grow line 202. Vertical grow tower conveyance system 200 may include sensors (such as RFID or bar code sensors) to identify a given grow tower 50 and, under control logic, select a grow line 202 for the grow tower 50. The load transfer conveyance mechanism 47 may also include one or more linear actuators that pushes the grow tower 50 onto a grow line 202. Similarly, the unload transfer conveyance mechanism 45 may include one or more linear actuators that push or pull grow towers from a grow line 202 onto a carriage of another powered and free conveyor mechanism, which conveys the carriages 1202 from the grow line 202 to the automated laydown station 41.
Grow Towers
Grow towers 50 provide the sites for individual crops to grow in the system. As
Grow towers 50 may include a set of grow sites 53 arrayed along at least one face of the grow tower 50. In the implementation shown in
U.S. application Ser. No. 15/968,425 filed on May 1, 2018, which is incorporated by reference herein for all purposes, discloses an example tower structure configuration that can be used in connection with various embodiments of the disclosure. In the implementation shown, grow towers 50 may each comprise three extrusions which snap together to form one structure. As shown, the grow tower 50 may be a dual-sided hydroponic tower, where the tower body 103 includes a central wall 56 that defines a first tower cavity 54a and a second tower cavity 54b.
U.S. application Ser. No. 15/968,425 discloses additional details regarding the construction and use of towers that may be used in embodiments of the disclosure. Another attribute of V-shaped grooves 58a, 58b is that they effectively narrow the central wall 56 to promote the flow of aqueous nutrient solution centrally where the plant's roots are located. Other implementations are possible. For example, a grow tower 50 may be formed as a unitary, single extrusion, where the material at the side walls flex to provide a hinge and allow the cavities to be opened for cleaning.
As
The use of a hinged front face plate simplifies manufacturing of grow towers, as well as tower maintenance in general and tower cleaning in particular. For example, to clean a grow tower 50 the face plates 101 are opened from the body 103 to allow easy access to the body cavity 54a or 54b. After cleaning, the face plates 101 are closed. Since the face plates remain attached to the tower body 103 throughout the cleaning process, it is easier to maintain part alignment and to insure that each face plate is properly associated with the appropriate tower body and, assuming a double-sided tower body, that each face plate 101 is properly associated with the appropriate side of a specific tower body 103. Additionally, if the planting and/or harvesting operations are performed with the face plate 101 in the open position, for the dual-sided configuration both face plates can be opened and simultaneously planted and/or harvested, thus eliminating the step of planting and/or harvesting one side and then rotating the tower and planting and/or harvesting the other side. In other embodiments, planting and/or harvesting operations are performed with the face plate 101 in the closed position.
Other implementations are possible. For example, grow tower 50 can comprise any tower body that includes a volume of medium or wicking medium extending into the tower interior from the face of the tower (either a portion or individual portions of the tower or the entirety of the tower length. For example, U.S. Pat. No. 8,327,582, which is incorporated by reference herein, discloses a grow tube having a slot extending from a face of the tube and a grow medium contained in the tube. The tube illustrated therein may be modified to include a hook 52 at the top thereof and to have slots on opposing faces, or one slot on a single face.
Vertical Tower Conveyance System
Hooks 52 may be injection-molded plastic parts. In one implementation, the plastic may be polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), or an Acetyl Homopolymer (e.g., Delrin® sold by DuPont Company). The hook 52 may be solvent bonded to the top of the grow tower 50 and/or attached using rivets or other mechanical fasteners. The groove-engaging member 58 which rides in the rectangular groove 1002 of the grow line 202 may be a separate part or integrally formed with hook 52. If separate, this part can be made from a different material with lower friction and better wear properties than the rest of the hook, such as ultra-high-molecular weight polyethylene or acetal. To keep assembly costs low, this separate part may snap onto the main body of the hook 52. Alternatively, the separate part also be over-molded onto the main body of hook 52.
As
At the junction between two sections of a grow line 202, a block 612 may be located in the t-slots 1004 of both conveyor bodies. This block serves to align the two grow line sections so that grow towers 50 may slide smoothly between them. Alternative methods for aligning sections of a grow line 202 include the use of dowel pins that fit into dowel holes in the extrusion profile of the section. The block 612 may be clamped to one of the grow line sections via a set screw, so that the grow line sections can still come together and move apart as the result of thermal expansion. Based on the relatively tight tolerances and small amount of material required, these blocks may be machined. Bronze may be used as the material for such blocks due to its strength, corrosion resistance, and wear properties.
In one implementation, the vertical tower conveyance system 200 utilizes a reciprocating linear ratchet and pawl structure (hereinafter referred to as a “reciprocating cam structure or mechanism”) to move grow towers 50 along a grow line 202.
The pivot point of the cams 602 and the means of attachment to the cam channel 604 consists of a binding post 606 and a hex head bolt 608; alternatively, detent clevis pins may be used. The hex head bolt 608 is positioned on the inner side of the cam channel 604 where there is no tool access in the axial direction. Being a hex head, it can be accessed radially with a wrench for removal. Given the large number of cams needed for a full-scale farm, a high-volume manufacturing process such as injection molding is suitable. ABS is suitable material given its stiffness and relatively low cost. All the cams 602 for a corresponding grow line 202 are attached to the cam channel 604. When connected to an actuator, this common beam structure allows all cams 602 to stroke back and forth in unison. The structure of the cam channel 604, in one implementation, is a downward facing u-channel constructed from sheet metal. Holes in the downward facing walls of cam channel 604 provide mounting points for cams 602 using binding posts 606.
Holes of the cam channel 604, in one implementation, are spaced at 12.7 mm intervals. Therefore, cams 602 can be spaced relative to one another at any integer multiple of 12.7 mm, allowing for variable grow tower spacing with only one cam channel. The base of the cam channel 604 limits rotation of the cams during the forward stroke. All degrees of freedom of the cam channel 604, except for translation in the axial direction, are constrained by linear guide carriages 610 (described below) which mount to the base of the cam channel 604 and ride in the t-slot 1004 of the grow line 202. Cam channel 604 may be assembled from separately formed sections, such as sections in 6-meter lengths. Longer sections reduce the number of junctions but may significantly increase shipping costs. Thermal expansion is generally not a concern because the cam channel is only fixed at the end connected to the actuator. Given the simple profile, thin wall thickness, and long length needed, sheet metal rolling is a suitable manufacturing process for the cam channel. Galvanized steel is a suitable material for this application.
Linear guide carriages 610 are bolted to the base of the cam channels 604 and ride within the t-slots 1004 of the grow lines 202. In some implementations, one carriage 610 is used per 6-meter section of cam channel. Carriages 610 may be injection molded plastic for low friction and wear resistance. Bolts attach the carriages 610 to the cam channel 604 by threading into over molded threaded inserts. If select cams 602 are removed, these bolts are accessible so that a section of cam channel 604 can be detached from the carriage and removed.
Sections of cam channel 604 are joined together with pairs of connectors 616 at each joint; alternatively, detent clevis pins may be used. Connectors 616 may be galvanized steel bars with machined holes at 20 mm spacing (the same hole spacing as the cam channel 604). Shoulder bolts 618 pass through holes in the outer connector, through the cam channel 604, and thread into holes in the inner connector. If the shoulder bolts fall in the same position as a cam 602, they can be used in place of a binding post. The heads of the shoulder bolts 618 are accessible so that connectors and sections of cam channel can be removed.
In one implementation, cam channel 604 attaches to a linear actuator, which operates in a forward and a back stroke. A suitable linear actuator may be the T13-B4010MS053-62 actuator offered by Thomson, Inc. of Redford, Va.; however, the reciprocating cam mechanism described herein can be operated with a variety of different actuators. The linear actuator may be attached to cam channel 604 at the off-loading end of a grow line 202, rather than the on-boarding end. In such a configuration, cam channel 604 is under tension when loaded by the towers 50 during a forward stroke of the actuator (which pulls the cam channel 604) which reduces risks of buckling.
Still further, as shown in
Other implementations for moving vertical grow towers 50 may be employed. For example, a lead screw mechanism may be employed. In such an implementation, the threads of the lead screw engage hooks 52 disposed on grow line 202 and move grow towers 50 as the shaft rotates. The pitch of the thread may be varied to achieve one-dimensional plant indexing. In another implementation, a belt conveyor include paddles along the belt may be employed to move grow towers 50 along a grow line 202. In such an implementation, a series of belt conveyors arranged along a grow line 202, where each belt conveyor includes a different spacing distance among the paddles to achieve one-dimensional plant indexing. In yet other implementations, a power-and-free conveyor may be employed to move grow towers 50 along a grow line 202.
Other configurations for grow line 202 are possible. For example, although the grow line 202 illustrated in the various figures is horizontal to the ground, the grow line 202 may be sloped at a slight angle, either downwardly or upwardly relative to the direction of tower travel. Still further, while the grow line 202 described above operates to convey grow towers in a single direction, the grow line 202 may be configured to include multiple sections, where each section is oriented in a different direction. For example, two sections may be perpendicular to each other. In other implementations, two sections may run parallel to each other, but have opposite directions of travel, to form a substantially u-shaped travel path. In such an implementation, a return mechanism can transfer grow towers from the end of the first path section to the onload end of the second path section of the grow line.
Irrigation & Aqueous Nutrient Supply System
As
Crops in grow towers 50 will generally take up nutrients from aqueous nutrient solution, thereby lowering nutrient levels in the excess nutrient solution returning to recirculation tank 1302. Irrigation system 1300 may also include nutrient and pH dosing system 1340, ion sensor 1342 and tank level sensor 1344. During operation, ion sensor 1342 may sample the nutrient solution at a predefined interval. During sampling, ion sensor 1342 may check the ion levels of 8 separate nutrients and compare them to desired nutrient levels. Ion sensor 1342 may be an 8-ion analyzer offered by CleanGrow Sensors of Wolverhampton, United Kingdom. Responsive to detected nutrient levels, nutrient and pH dosing system 1350 may inject a single element type dose to be delivered to the recirculation tank 1302, based on the nutrient mix desired, and the room available in the tank (as sensed by tank level sensor 1344, for the water needed to transport the dose). In some implementations, nutrient and pH dosing system 1350 may use the sensed nutrient data and a desired nutrient recipe to calculate a nutrient adjustment mix to adjust the nutrient levels of recirculation tank 1302, using the smallest available volume in the tank. Nutrient and pH dosing system 1340 may include one or more venturi injectors for dosing particular nutrient solutions into the irrigation loop. In one implementation, nutrient and pH dosing system 1340 is an AMI Penta Fertilizer Mixer unit offered by Senmatic A/S of Sanderso, Denmark.
Irrigation system 1300 may also include pressure transducer 1314 and flow sensor 1316 to monitor irrigation loop conditions and control the operation of supply pump 1304. Irrigation system 1300 may also use water from condensate collection mechanism 1348, in one implementation as a primary source of water for the nutrient water. Condensate collection mechanism 1348 recaptures condensate in the air contained within growth environment 20 using, in one implementation, mechanical dehumidification. Reverse osmosis system 1346 filters water received from an external water source, such as a municipal water system, to the extent irrigation system 1300 requires additional water. In some implementations, reverse osmosis system 1346 may also filter water received from condensate collection mechanism 1346. Irrigation system 1300 may also include components for ozone treatment and cleaning of aqueous nutrient solution. For example, ozone pump 1352 supplies aqueous nutrient solution to ozone treatment tank 1356 filtered by filter 1354. Bypass valve 1358 can be used to redirect ozone injected water to treat the screen filter.
Irrigation system 1300 may also include in-line pH dosing system 1318 and 5-in-1 sensor 1320. 5-in-1 sensor samples temperature, pH, Electrical Conductivity (EC), dissolved oxygen and oxidization reduction potential of aqueous nutrient solution. In-line pH dosing system 1318 can make micro-adjustments to pH levels based on sensed pH in the irrigation loop. The cooling loop 1380 may be controlled based on the temperature that is read by 5-1 sensor 1320. Irrigation system 1300 may also include bypass valve 1322 to allow the irrigation supply, sensing components, and/or the filter to run without aqueous nutrient solution reaching irrigation line 1306. Bypass valve 1322 can be used to test irrigation system 1300 and/or use bypass valve 1322 to divert aqueous nutrient solution from irrigation line 1306 until desired pH and other conditions are met.
As
As
Other implementations are possible. For example, the funnel structure may be configured with two separate collectors that operate separately to distribute aqueous nutrient solution to a corresponding cavity 54a, 54b of a grow tower 50. In such a configuration, the irrigation supply line can be configured with one hole for each collector. In other implementations, the towers may only include a single cavity and include plug containers only on a single face 101 of the towers. Such a configuration still calls for a use of a funnel structure that directs aqueous nutrient solution to a desired middle and back portion of the tower cavity, but obviates the need for separate collectors or other structures facilitating even distribution.
In operation, irrigation line 802 provides aqueous nutrient solution to funnel structure 902 that evenly distributes the water to respective cavities 54a, 54b of grow tower 50. The aqueous nutrient solution supplied from the funnel structure 902 irrigates crops contained in respective plug containers 158 as it trickles down. In one implementation, a gutter disposed under each grow line 202 collects excess aqueous nutrient solution from the grow towers 50 for recycling. In one implementation, the width of the gutter can be configured to be larger than the width of the grow towers 50 but narrow enough to act as a guide to prevent grow towers 50 from swinging. For example, the width of the gutter can be 0.5 inches larger than the width of the grow towers 50, and the walls of the gutter can be configured to extend an inch or more higher than the bottom of grow towers 50.
The apertures of irrigation line 802 can simply be holes drilled (or otherwise machined) into the pipe structure. Water, however, has a propensity to wick onto the surface of the pipe as it exits the apertures causing water to run along the pipe and drip down outside the funnel structure of the grow towers. In some implementations, the apertures can include structures directed to reducing or controlling possible leakage caused by the foregoing. For example, the apertures may be drilled holes with slotted spring pins pressed in, drilled holes with coiled spring pins pressed in, and drilled holes with a custom machined feature around the circumference made from a custom mill tool. All three of the solutions above are intended to create a sharp lip at the exit of the hole such that water cannot run along the pipe. Still further, separate emitters can be used at the select positions along the grow line 202.
Other solutions are possible. For example, an injection molded part with a sharp lip may be configured to snap into the aperture or hole drilled into the irrigation line pipe.
In one implementation, each aperture of irrigation line 802 may be fitted with nozzle 1602. In other implementations, the apertures at the second end (the end opposite the first end) of an irrigation line 802 (or the end of a section of irrigation line 802) may include an alternative nozzle 1702 including an air-bleed feature illustrated in
When the irrigation cycle begins and nutrient solution enters irrigation line 802, the solution pushes the air in the irrigation line 802 to the end of the line where it builds as one large pocket. With a nozzle having a shorter upper portion 1608, some of this air exits, but as the air is pushed out, water begins to cover the last (N) nozzle driving the air pocket above the water and above the last aperture. A new equilibrium is then obtained with water trickling out of the last aperture and a pocket of air sitting above the water. The air is then trapped and continues to exist in the line. Because the air takes up a volume, it prevents water from fully filling the irrigation line 802 thus creating flow out for the last aperture which is much less than at all other sites. Depending on the size of this air pocket, this weaker flow may exist for apertures (N−1, N−2, etc.) prior to the last (N) as well. The taller upper portion 1708 of nozzle 1702 allows for air to be constantly drained (i.e., small volumes of air at more frequent intervals). Because the top of the nozzle 1702 is at the top of inner surface of irrigation line 802 were the air pocket is located, air can always drain from this nozzle independently from the amount of water in the line. Unlike the shorter nozzle where a pocket of air may be trapped above the water in the line 802 and never able to exit (driving poor flow behavior), the longer nozzle 1702 allows air to more freely exit. In one implementation, the irrigation system supplies nutrient solution at a first end of the irrigation line 802. In such an implementation, nozzle 1702 is attached proximal to the second end of irrigation line 802 (or section of irrigation line 802). In other implementations, the irrigation system supplies nutrient solution to a middle portion of the irrigation line 802. In such an implementation, nozzle 1702 may be installed at both ends of irrigation line 802 (or sections thereof).
Gutter 1402 may consist of multiple separate sections that are joined together to form a unitary structure.
In one implementation, each grow line 202 is supported by a separate irrigation loop or zone that operates independently of irrigation loops associated with other grow lines in growth environment 20. In one implementation, each irrigation loop is supported by an irrigation skid that includes many of the components set forth in
Nutrient and pH dosing system 1340, in one implementation, is operably connected to multiple irrigation skids 1500 by associated plumbing, valves and other controls. An irrigation control system controls valves and associated plumbing components as needed to interface nutrient and pH dosing system 1340, and associated sensors, with a given irrigation skid 1500. The Nutrient and pH dosing system has the ability to purge and rinse between dosing intervals, in order to prevent mixing of nutrient water from one recirculating loop to another. During operation, the nutrient solution in each recirculating irrigation loop is sampled on a predefined interval for that specific loop. During sampling, the ion levels of 8 separate nutrients may be checked and compared to the desired nutrient levels for that specific loop. Nutrient and pH dosing system 1340 may inject a nutrient dose to be delivered to the recirculation tank 1504 for that loop, based on the nutrient mix required and the room available in the tank for the water needed to transport the dose.
An irrigation system 309 circulates water and nutrients through the plant support structure 304. Carbon dioxide supply equipment 311 provides carbon dioxide to the plants. The irrigation system 309 and carbon dioxide supply equipment 311 may be considered as part of the conditioning system 302, according to embodiments of the disclosure.
According to embodiments of the disclosure, the conditioning system 302 includes a dehumidifier 310, a fluid (e.g., water) conditioning system 312, and a heating coil 314 in heat exchanger 315. The dehumidifier 310 receives return air A from the grow space 101. The conditioning system 302 provides supply air B, having a temperature and relative humidity that is controlled to meet setpoints for desired operating conditions of the plants in the environment 20.
The fluid conditioning system 312 receives return fluid C from the fluid-cooled light fixture 308. According to embodiments of the disclosures, the fluid conditioning system 312 can control the fluid temperature by varying the fluid flow rate through the light fixtures 308. The fluid conditioning system 312 supplies to the fluid-cooled light fixture 308 a supply fluid D, having a temperature that is controlled to meet set points for desired operating conditions of the plants in the environment 20.
According to embodiments of the disclosure, waste heat from the fluid passing through fluid conditioning system 312 may be provided to the heating coil 314 in the heat exchanger 315 to heat air E that is output from the dehumidifier 310. The air heated by the coil 314 is output as heated air B to the grow space 20.
The controller 203 may control all the elements of the conditioning system 302, according to embodiments of the disclosure. The controller 203 may be implemented using programmed logic, such as a computer, a microcontroller, or an ASIC. The controller 203 may receive sensed parameters from sensors distributed throughout the plant growing environment 101 and the air and water conditioning system 302, according to embodiments of the disclosure. The sensors 204 may include sensors that sense environmental conditions such as temperature; humidity; air flow; CO2; irrigation flow rate; pH, EC, DO, and nutrient levels of irrigation water; and light intensity, spectrum, and schedule. The controller 203 may use the sensed parameters as feedback to instruct the conditioning system 302 to control environmental treatments (e.g., temperature, humidity) of the plant growing environment 101, according to embodiments of the disclosure.
Lighting 358 may comprise one or more light modules 362 (e.g., LED light modules) including, in some embodiments, a heat exchanger 359, such as heatsinks that facilitate heat transfer from lighting 358 to the air in the grow space 20. The heatsinks may be, e.g., aluminum blocks with fins to disperse heat into the air, structures with heatpipes and layers of fins (for example, CPU heatsinks), or the like. The controller 203 may control the heat transfer by controlling factors such as light intensity, duration, and air flow through the lighting 358.
According to embodiments of the disclosure reflected in
As in
The lighting 358 (e.g., light modules using LEDs) generates two types of heat. The first is heat generated, for example, directly at the LEDs, due to inefficiencies of converting electrical power to light. This type of heat, in some embodiments, corresponds to approximately 40% of the total power supplied to the lighting 358, depending on the light conversion efficiency of lighting 358. This heat contributes to the waste heat previously employed by the heat exchanger 315 in
The two types of heat originating with lighting 358 directly heats the air of the grow space 20, serving a function similar to the employment of waste heat from the lighting 308 to heat the grow space 20 of the system depicted in
One difference between the systems of
System components commonly used in industry can be used to capture heat from the return air or from inefficiencies in the vapor compression cycle. For example,
Supply air B has a temperature and relative humidity that is controlled to meet set points for desired operating conditions of the plants in the environment 20. Controller 203 may control all the elements of the conditioning system 302, according to embodiments of the disclosure. The controller 203 may receive sensed parameters from sensors distributed throughout the plant growing environment 20 and the air and water conditioning system 302, according to embodiments of the disclosure. Such sensors may include, for example, sensors that measure temperature, humidity, soil moisture, plant characteristics (e.g., size, shape, color), and irrigation flow rate. The controller 203 may also receive operating settings for those same parameters as well as others. The controller 203 may use the sensed parameters as feedback to instruct the conditioning system 302 to control environmental treatments (e.g., temperature, humidity) of the plant growing environment 20, according to embodiments of the disclosure. The controller 203 may employ machine learning or other predictive methods to adjust the treatments to achieve a desired objective relating to parameters such as ambient environmental conditions (e.g., temperature), energy usage, productivity, or plant product yield to energy use.
According to embodiments of the disclosure, the controller 203 may control evapotranspiration by controlling the following factors, whether alone or in any combination: irrigation, CO2 concentration, temperature, relative humidity, vapor pressure deficit, light intensity (e.g., based on daytime or nighttime condition), light wavelength (including electromagnetic radiation wavelength in the visible range and in the non-visible range, such as ultraviolet and infrared), light duration, light modulation (e.g., pulse width modulation), or air velocity, or by varying the supply of chemicals (e.g., hormones) that regulate transpiration. By increasing evapotranspiration, the controller 203 may cause a decrease in the sensible cooling load.
According to embodiments of the disclosure, the combination of mechanical equipment that is specified to remove water from the air and maintain the desired air temperature can vary widely, but there are some primary characteristics that they should typically include: (a) the equipment should be specified to remove an equivalent or larger amount of water than occurs during worst case transpiration and evaporation scenarios for both night and day; and (b) when heat is required to either warm the air or evaporate moisture, waste heat as a byproduct from other components in the system should be used. Waste heat may come from within the grow space (e.g., from lighting) or from the environmental control system 302 (e.g., from a compressor).
Referring to
The environmental control system 302 may employ Direct-Exchange (“DX”) equipment. DX equipment uses a vapor compression cycle to condition the air to a desired condition. At the evaporator of the DX equipment, the air is cooled to its saturation point and moisture condenses out, dehumidifying the air. Electronically controlled expansion valves and modulating hot-gas reheat are two features used with DX systems to incorporate the desired amount of heat back into the airstream, after dehumidification. Any heat that is not put back into the air will eventually be rejected, or sent to other energy recovery devices. Heat rejection can occur in a number of ways not limited to condensing units. Multiple rows of coils, variable speed fans, multiple vapor-compression circuits, air-side economization, and air bypasses are some of many ways that the DX unit can be configured to condition specific and varying loads with energy savings within one DX unit.
The environmental control system 302 may employ chilled water or chilled fluid air handling units that use a working fluid to cool, dehumidify, or heat the air to a desired condition. Chilled fluid can be provided by, but is not limited to, a chiller or fluid cooler. Heat-recovery chillers are one way that energy used in the cooling process can be re-used to heat the airstream back up to the desired condition. Chillers can be used in conjunction with other equipment that provides or removes heat, according to the embodiments of the disclosure. Boilers, solar heaters, heat pumps, the utilization of heat from lighting, and the utilization of heat from other equipment are just a few of the other ways that heat can be added to the airstream.
The environmental control system 302 may employ desiccant dehumidification either standing alone or in conjunction with other air-handling equipment to achieve a desired air condition with systems-level energy savings. Desiccants make use of a chemical that adsorbs moisture from the airstream. The chemical, or desiccants, used in desiccant dehumidifiers are able, when heated, to release the amount of moisture that was adsorbed to another fluid stream. In this process, heat is required to recharge the desiccants rather than to reheat air that has been cooled below the dew point. Although these systems are both energy efficient and have the ability to supply air at a low humidity, the capital cost may be high. One of several efficient applications of desiccant dehumidification is further dehumidifying air that has already been cooled by mechanical cooling equipment, prior to heating the air back up for delivery to the controlled environment.
The environmental control system 302 may employ energy wheels, enthalpy wheels or other air-to-air heat exchangers to further improve energy efficiency and recovery in air-handling units. A wrap-around heat pipe dehumidifier exchanges sensible heat of the outgoing airstream with the incoming airstream, with a cooling coil in-between. In this configuration, air that passes over the coil exchanges heat with incoming air, pre-cooling the incoming air and heating the outgoing air; the net effect of this is less cooling energy required at the coil. Total energy wheels and enthalpy wheels are just some of the heat exchange equipment that can be used in system-level optimization for energy and cost.
Carbon dioxide supply and control is also a component of the design. Control of carbon dioxide levels in the grow space affects evapotranspiration rate and components of plant growth. Carbon dioxide control, with other control variables such as, but not limited to, light intensity, vapor-pressure deficit, fan speed and airflow velocity control, and nutrient supply, are ways that the conditioning system 602 can control latent load for a controlled agriculture environment.
The economizer 2102 includes an economizer intake damper XC012114 and an economizer exhaust damper XC032118. HVAC dampers FC04-FC092120 control the supply of air from air conditioning subsystem 2104 to the grow room zones. According to embodiments of the disclosure, the controller 203 may close the end dampers FC042120 and FC092120 at certain times of the day to drive more airflow at different canopy positions for specific plants. Air conditioning subsystem 2104 operates similarly to conditioning system 302 of
Within the dehumidification unit are three proportional valves (TCV03, TCV02, and TCV01) that control flow of warm and cold water to three heat exchangers 2306, 2304, 2200 that are used to heat (TCV03), cool (TCV02), and dehumidify (TCV01). The fans 2202 (SA Flow fans) blow air to the grow room 20, and dampers FC04-FC092120 are used to control the air flow to each of the supply ducting outputs of the line. Return Air is moved across the dehumidification coils to dehumidify the air. In normal operation mode, XC012114 and XC032118 are closed and XC022130 is open and no blending with outside air using economization is utilized.
In operation, the supply pump 2320 pumps nutrient-enriched water from the supply tank 2302 through the supply line 2310 to the branch irrigation lines 2316 via the main irrigation line 2314. The water flows from the nozzles into the receptacle supports. Any water not retained in the receptacle supports flows into the gutter 2318. The flow sensor monitors flow rate in the supply line 2310.
A supply pump 2406 pumps water from a supply tank 2408 via a supply line 2410 to the propagation tables 2402, 2404. According to embodiments of the disclosure, a three-way recirculation valve 2412 controls whether the water from the supply tank 2408 is directed back to the tank 2408 or allowed to pass on to the propagation tables 2402, 2404.
Water sensors 2414 are coupled to the supply line 2412 to measure pH, dissolved oxygen, ozone, temperature and electrical conductivity, nutrients such as calcium, phosphorus, and nitrates, among other parameters to determine water quality. A nutrient injector valve 2416 controls the flow of nutrients into the supply tank 2408.
Evapotranspiration-Triggered Irrigation
Depending on lifecycle and varying optimal conditions, watering plants the same consistent volume every watering cycle is not efficient or desired. Using feedback from the indoor farm environmental control system allows for varying irrigation volumes that are more closely tailored to the needs of the plants at any given time and therefore provides more efficient and optimal irrigation practices.
The plant media can dry out due to evaporation and transpiration, which vary depending on plant age and other conditions in the grow room 20. With reference to
As noted with respect to
According to embodiments of the disclosure, a condensation drainage line 382 carries the condensate from dehumidifier 310 to irrigation system 309. According to embodiments of the disclosure, flow meter 380 measures the flow rate of the condensate. This volume is a direct measurement of the water evaporated and transpired from the grow media. As a result, the environmental conditioning system 302 can trigger watering events at the frequency required to avoid media dryout.
For example, the controller 203 may trigger the irrigation system 309 to water the following plant 306 varieties under the following conditions. (Note that flow rate is representative of condensate volume; that is volume=flow rate*time.) The irrigation system 309 may replenish the volume of the water evaporated and transpired from the grow media. Thus, the supply volume may be derived by totalizing the condensate collection flow over the period of time since the last watering. For example, the supply volume may equal the total condensate volume since the last watering. According to embodiments of the disclosure, instead the supply volume may be partially and not be fully replenished, or may be more than the measured condensate volume.
With reference to the table below, for variety #1 the controller 203 may trigger the supply system 309 to replenish the lost water volume by supplying 1500 liters of water in response to the condensate volume reaching 1500 liters.
In practice, the irrigation system can be implemented using any dehumidification technology (e.g., chilled water, direct refrigerant expansion, desiccant) and any method of measuring the condensed water volume (e.g., flow meter, flow totalizer, tank with level sensor, or supply and return air temperature and humidity sensors using known psychrometric techniques).
Machine Learning
Embodiments of the disclosure may apply machine learning (“ML”) techniques, e.g, to learn the relationship between the given parameters (e.g., environmental conditions such as temperature, humidity) and observed outcomes (e.g., experimental data concerning yield and energy consumption). Embodiments may use ML models, e.g., Decision Trees, to determine feature importance. In general, machine learning may be described as the optimization of performance criteria, e.g., parameters, techniques or other features, in the performance of an informational task (such as classification or regression) using a limited number of examples of labeled data, and then performing the same task on unknown data. In supervised machine learning such as an approach employing linear regression, the machine (e.g., a computing device) learns, for example, by identifying patterns, categories, statistical relationships, or other attributes exhibited by training data. The result of the learning is then used to predict whether new data will exhibit the same patterns, categories, statistical relationships or other attributes.
Embodiments of this disclosure may employ unsupervised machine learning. Alternatively, some embodiments may employ semi-supervised machine learning, using a small amount of labeled data and a large amount of unlabeled data. Embodiments may also employ feature selection to select the subset of the most relevant features to optimize performance of the machine learning model. Depending upon the type of machine learning approach selected, as alternatives or in addition to linear regression, embodiments may employ for example, logistic regression, neural networks, support vector machines (SVMs), decision trees, hidden Markov models, Bayesian networks, Gram Schmidt, reinforcement-based learning, cluster-based learning including hierarchical clustering, genetic algorithms, and any other suitable learning machines known in the art. In particular, embodiments may employ logistic regression to provide probabilities of classification along with the classifications themselves.
Embodiments may employ graphics processing unit (GPU) or Tensor processing units (TPU) accelerated architectures that have found increasing popularity in performing machine learning tasks, particularly in the form known as deep neural networks (DNN). Embodiments of the disclosure may employ GPU-based machine learning, such as that described in GPU-Based Deep Learning Inference: A Performance and Power Analysis, NVidia Whitepaper, November 2015, Dahl, et al., which is incorporated by reference in its entirety herein.
Computer System Implementation
Program code may be stored in non-transitory media such as persistent storage in secondary memory 2810 or main memory 2808 or both. Main memory 2808 may include volatile memory such as random access memory (RAM) or non-volatile memory such as read only memory (ROM), as well as different levels of cache memory for faster access to instructions and data. Secondary memory may include persistent storage such as solid state drives, hard disk drives or optical disks. One or more processors 2804 reads program code from one or more non-transitory media and executes the code to enable the computer system to accomplish the methods performed by the embodiments herein. Those skilled in the art will understand that the processor(s) may ingest source code, and interpret or compile the source code into machine code that is understandable at the hardware gate level of the processor(s) 2804. The processor(s) 2804 may include graphics processing units (GPUs) for handling computationally intensive tasks.
The processor(s) 2804 may communicate with external networks via one or more communications interfaces 2807, such as a network interface card, WiFi transceiver, etc. A bus 2805 communicatively couples the I/O subsystem 2802, the processor(s) 2804, peripheral devices 2806, communications interfaces 2807, memory 2808, and persistent storage 2810. Embodiments of the disclosure are not limited to this representative architecture. Alternative embodiments may employ different arrangements and types of components, e.g., separate buses for input-output components and memory subsystems.
Those skilled in the art will understand that some or all of the elements of embodiments of the disclosure, and their accompanying operations, may be implemented wholly or partially by one or more computer systems including one or more processors and one or more memory systems like those of computer system 2800. In particular, the elements of automated systems or devices described herein may be computer-implemented. Some elements and functionality may be implemented locally and others may be implemented in a distributed fashion over a network through different servers, e.g., in client-server fashion, for example.
Although the disclosure may not expressly disclose that some embodiments or features described herein may be combined with other embodiments or features described herein, this disclosure should be read to describe any such combinations that would be practicable by one of ordinary skill in the art. Unless otherwise indicated herein, the term “include” shall mean “include, without limitation,” and the term “or” shall mean non-exclusive “or” in the manner of “and/or.”
All references cited herein, including, without limitation, articles, publications, patents, patent publications, and patent applications, are incorporated by reference in their entireties for all purposes, except that any portion of any such reference is not incorporated by reference herein to the extent it: (1) is inconsistent with embodiments of the disclosure expressly described herein; (2) limits the scope of any embodiments described herein; or (3) limits the scope of any terms of any claims recited herein. Mention of any reference, article, publication, patent, patent publication, or patent application cited herein is not, and should not be taken as an acknowledgment or any form of suggestion that it constitutes valid prior art or forms part of the common general knowledge in any country in the world, or that it discloses essential matter.
In the claims below, a claim n reciting “any one of the preceding claims starting with claim x,” shall refer to any one of the claims starting with claim x and ending with the immediately preceding claim (claim n−1). For example, claim 35 reciting “The system of any one of the preceding claims starting with claim 28” refers to the system of any one of claims 28-34.
This application is a continuation-in-part of U.S. application Ser. No. 16/893,833, filed 6 Jun. 2020, which claims the benefit of priority to U.S. Provisional Application Nos. 62/903,795, filed 21 Sep. 2019, and 62/858,273, filed 6 Jun. 2019. This application is related to U.S. application Ser. No. 17/753,703, filed 11 Mar. 2022, as a national stage entry of PCT/US20/51030, filed 16 Sep. 2020, which claims the benefit of priority of U.S. Provisional Application No. 62/903,515, filed 20 Sep. 2019. All of the foregoing applications are incorporated by reference herein.
Number | Date | Country | |
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62903795 | Sep 2019 | US | |
62858273 | Jun 2019 | US |
Number | Date | Country | |
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Parent | 16893833 | Jun 2020 | US |
Child | 18053596 | US |