Patent Publication Number: US-2023148498-A1

Title: Location awareness and gesture control for an electronically controlled sprinkler system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application is a continuation-in-part of U.S. application Ser. No. 17/577,076, filed Jan. 17, 2022, which is a continuation-in-part of U.S. application Ser. No. 16/439,778 filed Jun. 13, 2019, now U.S. Pat. No. 11,226,054 issued Jan. 18, 2022, which also claims the benefit of U.S. Provisional Patent Application No. 62/815,726, filed Mar. 8, 2019, the entire contents of which are incorporated herein by reference. 
     The present application also claims the benefit of U.S. Provisional Patent Application No. 63/300,089, filed Jan. 17, 2022, the entire contents of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     Embodiments of the invention relate to water sprinkler systems, and more particularly to programmable electronically controlled sprinkler systems which are controllable to affect sprinkler direction and time of watering. 
     The particular improvements discussed herein relate to location awareness of the system based on physical location of the unit relative to one or more base platforms, as well as gesture/motion control of the unit through the use of an on-board accelerometer. 
     SUMMARY OF THE INVENTION 
     A smart sprinkler system in accordance with the present disclosure delivers water from a pressurized water supply to any location within its range via a spray nozzle or sprinkler head that can be rotated in any direction. The distance of the spray field is determined by the water pressure. The term “smart”, in the context of the present system, refers to its ability to be controlled wirelessly using a “smart” device, such as a smart phone or tablet that can run an associated application that communicates with the control electronics of the system. Once configured, the sprinkler functionality is controlled by the device autonomously. This division of labor, the sprinkler device performing the functions of the sprinkler and the phone/tablet providing the Graphical User Interface (GUI), leverages the power of a device that is designed specifically for providing rich and familiar user interfaces, while alleviating the cost and complexity of providing a user interface on the sprinkler. 
     A defining characteristic of the sprinkler system is that it is able to deliver a small footprint of water to a specific location in a reproducible manner. The sprinkler head rotates about a vertical axis, so the specification of a location is represented in polar coordinates as an angle and a pressure, where the pressure is related to the radial distance from the sprinkler head. The area of water striking the ground can best be envisioned as a narrow rectangle or short line segment radial to the nozzle. The orientation of the rectangle lengthwise along the radius is also intentional, as the primary means of distributing the water in a pattern is by sweeping it about an arc. A sprinkler pattern is created as a series of curves, with each curve being defined as a change of pressure and change of rotation angle. Each pressure represents a distance from the sprinkler head. If the pressure is changed, but the rotation angle is not, then the movement would describe a radial line segment emanating from the sprinkler head at the center. If the rotation is changed, but the pressure is not, then the movement describes an arc with a radius proportional to the pressure and endpoints corresponding to the starting and ending angles of rotation. If both the pressure and rotation angles change then the movement describes a curve that approximates an average of two arcs at the two pressures with the same rotational endpoints. These movements effectively amount to vectors described in polar coordinates, where the change in pressure represents the radial component and the change in rotation represents the component along an arc. Note that sufficiently small movements may be used to approximate straight lines. As the sprinkler describes a curve over time, a narrow band of spray is produced along the arc component. A user is able to describe a series of points and curves, which together combine into a predefined area, or watering pattern, as the sprinkler sweeps across between each pair of points in sequence. 
     The electrical components associated with the direct control of the sprinkler system may comprise two low-power DC motors: one for a pressure control valve and the other for a diverter that controls the rotational direction of the spray nozzle. The motors provide input to magnetic couplings. The valve control motor is used to open and close the piloted valve incrementally and the diverter motor is used to rotate an armature to change the flow path in an oscillator which drives the sprinkler head in either direction or may hold it stationary. 
     The microcontroller unit (MCU) performs all functions related to the control of the sprinkler system using software stored in non-volatile memory within the MCU itself. The MCU also includes storage, both volatile (RAM) and non-volatile, for storing data associated with the running of the device. The MCU also provides a short-range radio used to provide a wireless interface used by the external smart device to configure and control the sprinkler remotely. The firmware defines and implements a command interface to provide these capabilities. Additionally, the MCU provides timing and counting functions that allow the device to control when it starts or stops. It may be configured to, for example, run a user-defined pattern for a specified duration or to be repeated a specified number of times before shutting itself off 
     Improvements to the current system include location inputs (RFID tagging) which allows the unit to distinguish between a plurality of different base locations which would each have their own unique program patterns, as well as the provision of hand gesture input (accelerometer) to allow the unit to be controlled in a manual mode when not in a preprogrammed pattern mode or to otherwise react to changes in orientation (e.g. for tip detection). 
     Accordingly, it can be seen that the present system provides several unique and novel improvement over systems of the prior art, particularly with respect to sealed chamber magnetic couplers which eliminate the need for high friction seals for rotating parts and which also reduce power needs for rotating components within the sealed chambers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the present invention can be more readily understood and appreciated by one of ordinary skill in the art from the following descriptions of various embodiments of the invention when read in conjunction with the accompanying drawings in which: 
         FIG.  1    illustrates an exemplary sprinkler system block diagram in accordance with the present invention; 
         FIG.  2    illustrates an exemplary configuration of the present sprinkler system; 
         FIG.  3    illustrates an exemplary spray pattern using an angled nozzle head 
         FIG.  4    diagrammatically illustrates an area to be watered overlaid with an exemplary programmed watering pattern which can be implemented with software for controlling the present invention; 
         FIG.  4 A  illustrates rotation of the sprinkler head and adjustments of water pressure for distance to transcribe the desired watering pattern; 
         FIG.  4 B-C  diagrammatically illustrate another exemplary programmed watering pattern using a different algorithm where the pressure and rotation are changing concurrently in a vector system with polar coordinates; 
         FIG.  5    is a bottom perspective view of an exemplary magnetic coupling and limit switch system illustrating the external drive components; 
         FIG.  6    is a side view thereof illustrating both the external drive components and the internal follower components; 
         FIG.  7    is a top perspective view thereof illustrating the internal follower arm and mechanical stops; 
         FIG.  8    is a top view thereof; 
         FIG.  9    is an exploded perspective view thereof illustrating the alignment of the coupling magnets captured in the internal and external coupling components; 
         FIGS.  10 A and  10 B  illustrate coupled rotation of the magnets when freely moving and continued rotation and axial translation of the external magnet when the internal magnet is restricted by a mechanical stop; 
         FIG.  11    illustrates an exemplary pilot valve which is adapted for variable pressure control with a magnetically actuated lead screw; 
         FIG.  12    illustrates a full assembly view of the pilot valve pressure control; 
         FIG.  13    is a perspective view thereof shown partially in transparency; 
         FIG.  14    is a cross-sectional view thereof taken along line  14 - 14  of  FIG.  12   ; 
         FIG.  15    is an exploded perspective view of the valve control mechanism for the pilot valve; 
         FIG.  16    is a plan view of an exemplary oscillator/diverter mechanism in accordance with the present invention; 
         FIG.  17    is another plan view thereof shown partially in transparency; 
         FIG.  18    is a bottom perspective view thereof showing the external drive components of the magnetic coupling system; 
         FIG.  19    is a perspective view of the diverter assembly; 
         FIG.  20    is an exploded perspective view of the diverter control magnetic coupling input; 
         FIG.  21    is a top view of the diverter control; 
         FIG.  22    is an exploded perspective view of the turbine chamber in position above the output of the diverter; 
         FIG.  23    is a top view thereof showing the relationship of the diverter armature and the flow ports of the oscillator chamber; 
         FIG.  24    is an exploded perspective view of an exemplary embodiment including multiple mounting bases each including a unique RFID for location awareness and sprinkler programming and operation based on the unique location ID; and 
         FIG.  25    is an enlarged cross-sectional view taken along line  25 - 25  of  FIG.  24    showing the RFID alignment with an internal RFID reader. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Certain exemplary embodiments will now be described to provide an overall understanding of the principles of the structure, function, manufacture, and use of the device and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments and that the scope of the present invention is defined solely by the claims. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure. Further, in the present disclosure, like-numbered components of the embodiments generally have similar features, and thus within a particular embodiment each feature of each like-numbered component is not necessarily fully elaborated upon. Additionally, to the extent that linear or circular dimensions are used in the description of the disclosed systems, devices, and methods, such dimensions are not intended to limit the types of shapes that can be used in conjunction with such systems, devices, and methods. A person skilled in the art will recognize that an equivalent to such linear and circular dimensions can easily be determined for any geometric shape. Further, to the extent that directional terms like top, bottom, up, or down are used, they are not intended to limit the systems, devices, and methods disclosed herein. A person skilled in the art will recognize that these terms are merely relative to the system and device being discussed and are not universal. 
     Referring generally to  FIGS.  1  through  4   , a smart sprinkler system in accordance with the present disclosure is illustrated and generally indicated at  10 . The smart sprinkler system  10  delivers water from a pressurized supply  12  to any location within its range via a spray nozzle or sprinkler head  14  that can be rotated in any direction. The spray nozzle  14  includes at least one, but preferably a plurality of, angled orifices  16  which create an elongated, somewhat narrow spray field  18  as generally illustrated in  FIG.  3   . The distance “D” of the spray field  18  is determined by the water pressure. The term “smart”, in the context of the present system  10 , refers to its ability to be controlled (wired or wirelessly) using a “smart” device  20 , such as a smart phone or tablet that can run an associated application that communicates with the control electronics  22  of the system  10 . The present system is implemented in a wireless configuration, and in particular, the wireless interface implemented in this exemplary system is a Bluetooth Low Energy (BLE) interface which is common to the category of personal devices known as smart devices (e.g. mobile phones, tablets). 
     It should be understood that other wired and wireless interfaces and standards could also be implemented with the same functionality. Indeed, the smart sprinkler system  10  requires a smart device  20  to control and configure the sprinkler system  10  using an associated application as noted above. Any electronic interface that is capable of supporting commands is a viable possibility. Once configured, much of the sprinkler functionality is controlled by the device autonomously. This division of labor, the sprinkler device  10  performing the functions of the sprinkler and the/phone/tablet device  20  providing the GUI, leverages the power of a device that is designed specifically for providing rich and familiar user interfaces, while alleviating the cost and complexity of providing a user interface on the sprinkler. 
     A defining characteristic of the sprinkler system  10  is that it is able to deliver a small footprint  18  of water to a specific location in a reproducible manner. There are several possible methods for accomplishing this goal. 
     The sprinkler head  14  rotates about a vertical axis, so the specification of a location can be represented in polar coordinates as an angle and a pressure, where the pressure is related to the radial distance D from the sprinkler head. The footprint of water striking the ground can best be envisioned as a narrow rectangle or short line segment radial to the nozzle  14 . The footprint  18  is by design and represents a balance between having a fine resolution for placing water and avoiding too high a density of water striking the ground at a single location. The orientation of the rectangle lengthwise along the radius is also intentional, as the primary means of distributing the water in a pattern is by sweeping it over a curve. 
     In a first exemplary method, a sprinkler pattern is created as a series of arcs  24   a ,  24   b ,  24   c  ( FIGS.  4  and  4 A ), with each arc being defined as a pressure and two angles. The pressure represents the radius of the arc and the two angles represent the left and right ends or stops  26 A,  26   b  of the associated arc. As the sprinkler describes the arc  24  over time, a narrow band of spray  18  is produced. A user is able to describe a series of arbitrary concentric arcs  24 , which together combine into an arbitrary defined area as the sprinkler sweeps across each arc in sequence. 
     In a second exemplary method, the curve is defined by two points P 1 , P 2  with a change in pressure and change in rotation angle, relative to the sprinkler head S, which defines the center of a circle. The curve is, essentially a vector v in polar coordinates with a radial component r and an arc component a ( FIG.  4 C ). A sprinkler, or watering, pattern is created as a sequence of such vectors  24   a  . . .  24   n  ( FIG.  4 B ). As the sprinkler describes each curve  24  over time, a narrow band of spray  18  is produced. In describing a sequence of curves, a path is followed, which in totality deposits a volume of water on an area. A user is able to describe an arbitrary sequence of these curves  24  by defining the points P 1 , P 2 , Pn. A schematic illustration of an area to be watered overlaid with such a sequence  24   a  . . . is illustrated in  FIG.  4 B . 
     It is also a defining characteristic of the sprinkler system  10  that it is able to operate with only a single connection to a water source  12  and in some embodiments does not require a connection to external electric power. This allows the present sprinkler system  10  to be a direct replacement for a typical lawn sprinkler, which is mechanically driven entirely by the energy provided by the supply pressure of the water source. Unlike a mechanical lawn sprinkler, which only provides one pressure (that of the supply) and one set of stops and can, therefore, only supply one pattern that is either roughly rectangular or circular (depending on the type), the present sprinkler system can create arbitrarily shaped patterns. It achieves this by using a circular lawn sprinkler mechanism to drive the rotation of the sprinkler head  14 , but with an electric motor (oscillator/diverter mechanism  300 —described below) to actuate the mechanism that controls the direction of the rotation. Additionally, present the sprinkler system  10  explicitly controls the water pressure delivered to the spray nozzle, up to the maximum of the supply pressure (i.e. there is no pump to add pressure above that of the supply). The system achieves this using an adjustable piloted valve (pilot valve assembly  200 ), which maximizes the use of the supplied pressure to affect changes to the valve. In short, the mechanism is designed to use as little energy as practicable. 
     In the present wireless configuration, required electrical energy is harvested from two sources: a hydro generator  28  in line with the water flow between the pressurized supply  12  and the nozzle  14  (input and output, respectively) and a solar panel  30 . Both sources provide DC electricity used to power the electronics  22 , MCU/memory  32 , wireless radio  34 , motor control  36  and sensors  38  that comprise the control system. 
     The hydro generator  28  provides energy while the sprinkler is active (i.e. water is flowing through it) and the solar panel  30  captures energy from the sun, regardless of whether the sprinkler is active. Since the sprinkler is always consuming energy, the power system includes a rechargeable battery  40  and a battery charge controller  42 . Thus, the two power sources  28 .  30  are used to put energy into the battery  40 , even as the device consumes energy. The energy system is balanced, such that it requires no additional power source under normal use. There is, however, an electrical connection (not shown) for attaching to an external charger for expediting an initial charge before first use or after storage. 
     In a wired system, the rechargeable battery  40 , charge controller  42 , hydro generator  28  and solar panel  30  could be eliminated to reduce complexity and cost. 
     The electrical components associated with the direct control of the sprinkler system  10  may comprise two low-power DC motors: one motor  202  for a piloted pressure control valve system  200  (See  FIGS.  11 - 15   ) and the other motor  302  for a diverter system  300  (See  FIGS.  16 - 23   ) that controls the rotational direction of the spray nozzle  14 . The motors  202 ,  302  provide the input to magnetic couplings  204 ,  304  (further described below). The speed, duration and direction of the motors  202 ,  302  are controlled by algorithms running on a Microcontroller Unit (MCU)  32 . The valve motor  202  is used to open and close a piloted valve system  200  incrementally and the diverter motor  302  is used to rotate an armature of the diverter assembly  300  to change the flow path in an oscillator which drives the sprinkler head  14  in either direction or may hold it stationary. 
     In order to provide closed loop control over the system, there are two sensors: a pressure sensor  400  and a magnetic rotational sensor  500 . The pressure sensor  400  is embedded in the oscillator chamber of the oscillator/diverter assembly  300  and measures the water pressure delivered to the nozzle  14 . When the desired pressure setpoint has been configured, the pressure sensor  400  supplies input to the algorithm, which opens and closes the pressure control valve  200  to maintain the nozzle pressure about the setpoint within a hysteresis range. This allows a pressure to be maintained without calibration of the supply pressure and as the supply pressure changes over time. Note that the output pressure is limited at an upper end by the native supply pressure (i.e. there is no mechanism for increasing the pressure beyond the supply pressure). 
     It should also be noted that additional environmental sensors  39 , or smart sensors may also be deployed with and communicate with the present control system  32  (wired or wirelessly) to provide additional operational input. Sensors  39  may comprise temperature sensors, atmospheric pressure sensors, light sensors, rain sensors, moisture sensors, infra-red heat sensors etc. to provide additional inputs to control or modify run days, run times, or run locations as configured. 
     The magnetic rotational sensor  500  is external to the oscillator chamber of the oscillator/diverter assembly  300  and in line with a magnet that is mechanically held to the rotational axis of the sprinkler head  14  or indirectly in correspondence with the sprinkler head  14 . The magnetic field is diametric to the axis of rotation, which allows the sensor  500  to determine the angle of rotation of the sprinkler head  14  within a resolution less than one degree. This allows the algorithm to determine when the sprinkler head  14  has rotated to a desired angle and to then change the direction of rotation or stop the rotation using the motor  302  associated with the diverter armature. 
     The MCU  32  performs all functions related to the control of the sprinkler system  10  using software stored in non-volatile memory (firmware) within the MCU itself. The MCU  32  also includes storage, both volatile (RAM) and non-volatile, for storing data associated with the running of the device (e.g. the data defining a user-defined pattern). The MCU  32  also provides the radio  34  (Bluetooth) used to provide a wireless interface used by the external smart device  20  to configure and control the sprinkler remotely. The firmware defines and implements a command interface to provide these capabilities. Additionally, the MCU  32  provides timing and counting functions that allow the device to control when it starts or stops. It may be configured to, for example, repeat a user-defined pattern (See  FIG.  4   ) for a specified duration or a specified number of times before shutting itself off. 
       FIG.  1    shows a block diagram of the components of the sprinkler  10  that enable all of the capabilities described above. The ultimate purpose of the system  10  is to deliver water from a supply to desired locations.  FIG.  1    illustrates the path of the water flow (thicker arrows “W”) through the system as it controls the water and extracts energy from the water to power the system.  FIG.  1    also illustrates the path of energy (thinner arrows “E”) as it is generated from the hydro generator  28  and solar panel  30 , stored in the battery  40  and utilized. The system is also responsible for control, so the diagram shows the path of the control and data signals (lines “C”). Finally, the system offloads the responsibility for providing a user interface to the external smart device  20  and the wireless control interface for communication with the external smart device  20  is also illustrated. 
     Referring to  FIG.  2   , the water supply flows, first, into the pressure control valve assembly  200 . The pressure control valve  200  is capable of shutting off the water supply entirely as well as providing a desired set water pressure from zero up to roughly the maximum limit of the native supply pressure. The water then flows into the hydro generator  28 . A minimum amount of water pressure is required before the turbine inside the generator  28  will spin. Once it begins to spin, the output energy is relative to the speed of rotation or the output pressure of the control valve assembly  200 . The water flow exits the hydro generator  28  and enters the oscillator/diverter assembly  300 , which determines the direction of rotation of the sprinkler head  14 . 
     The oscillator/diverter  300  achieves this by directing water through ports that lead to an oscillator turbine. Generally, each port directs water to one side or the other of the turbine, each port corresponding to one direction of rotation. The rotating turbine provides the mechanical energy to turn the sprinkler head  14 . A diverter chamber also provides a direct path to the sprinkler head through a pressure relief valve. This allows excess water pressure to bypass the oscillator, which limits the maximum speed of rotation of the sprinkler head  14 . 
     The electrical energy of the system includes rechargeable battery  40 , allowing the sprinkler system  10  to be run over a wide range of circumstances. The battery  40  allows the energy to be budgeted, so that the energy generated does not have to be explicitly associated with energy consumption of specific components. Rather, generated energy is added to the battery  40  and energy consumed comes from the battery  40 . This is all managed by the battery charge controller  42 , which also performs voltage regulation. The battery charge controller  42  directs energy from the hydro generator  28 , which is in the range of 0-5V, and the solar panel  30 , which is in the range of 0-6V, into the rechargeable battery  40  (See  FIG.  1   ). The variability of voltage stems from the fact that the generator  28  is not always running, and its RPMs are relative to the output water pressure. The solar panel  30  only produces energy during the day and its output is relative to the amount of direct sunlight. The energy consumed depends on whether the sprinkler is running. When it is running, the electronics associated with the motors  202 ,  302  and the sensors  400 ,  500  require 5V and represent the bulk of the energy consumption. The motor control circuit  36  and the sensors  400 ,  500  are powered only while the sprinkler is active. The motors  202 ,  302 , which are the greatest consumers of energy by a factor of 10 are only driven intermittently and for relatively short durations. The MCU  32 , which includes the radio  34 , is always consuming some amount of energy, even when the sprinkler is off. Running at 3.3V, the energy consumption is less at its maximum, when the radio  34  is actively linked to the external smart device  20 , than the electronics. The energy consumption is smaller when the system  10  is running autonomously versus when the system  10  is being remotely controlled. The control signals that trigger the motor driver and sense the output of the pressure and rotation sensors are components of this low voltage/power consumption. 
     Turning now to  FIGS.  5 - 10   , an exemplary magnetic coupling and switch assembly for use with a sealed chamber system is generally indicated at  100 . The assembly  100  is generally used to transfer a rotational mechanical input force that is external to a sealed chamber  102  to a rotational mechanism that is internal to the chamber  102  which may be filled with fluid  104  under pressure. The exemplary embodiment shown in  FIGS.  5 - 10    is a universal configuration that could be used in any sealed chamber system to translate external motion to an internal component and to provide a linear (axial) switching actuator external to the chamber  102 . These general magnetic coupling and actuator principles are used in conjunction with two separate systems described with the present system hereinafter. First, for rotation of the lead screw of a variable pressure pilot valve system generally indicated  200  ( FIGS.  11 - 15   ). Second, for rotation of an oscillator/diverter lever in a water driven turbine rotation system  300  for the spray nozzle ( FIGS.  16 - 23   ). 
     The magnetic coupling assemblies have the following characteristics: 
     The internal chamber  102  is hermetically sealed. There are no mechanical components penetrating the chamber which would require hydraulic seals. 
     The connection between the external and internal members introduce minimal friction, due to the elimination of seals and due to the force vectors associated with the magnetic fields. 
     The magnetic coupling uniquely provides the ability for an external sensor to detect when the internal mechanism has reached a hard stop. 
     The magnetic coupling also inherently functions as a safety clutch, allowing the coupling to disengage without damage or wear. 
       FIGS.  5 - 8    illustrate the components that are both external to the chamber  102  and internal to the chamber. The boundary between internal and external is defined by the wall  106 . The inside of the chamber  102  being above the wall  106  and further defined by walls  108  illustrated in broken line in  FIG.  6   . In the drawing figures, the external components are below the boundary wall  106 . The active external components are mounted on a fixed stand  110 , which maintains the position and orientation of the external components relative to each other and to the internal components. The exemplary mechanism is driven by a reversible motor  112 . A motor gear  114  is mounted to the motor shaft (not shown). The motor gear  114  engages with and drives a magnetic coupling gear  116 . The magnetic coupling gear  116  has a square hole  118  traversing it from top to bottom (See  FIG.  9   ). In this hole, is an external square magnet  120  ( FIG.  9   ) abutting the chamber boundary wall  106  and a magnet adapter  122  (also in  FIG.  9   ) that couples the magnet  120  to a limit switch  124 . Note that a bracket holding the limit switch  124  is not shown. The magnet  120  and the magnet adapter  122 , being square are not able to rotate freely within the magnetic coupling gear  116 , so that the rotation of the magnetic coupling gear  116  is transmitted to the magnet  120  and the magnet adapter  122 , making them also driven by the coupling gear  116 . The magnet  120  and the magnet adaptor  122  can move freely in the direction perpendicular to the chamber boundary wall  106  (axially along the axis of rotation of the magnetic coupling gear  116 ). This axial motion of the magnet  120  causes the limit switch  124  to actuate, closing and opening as the magnet  120  and magnet adaptor  122  move away from and toward the chamber boundary wall  106 , respectively. 
       FIGS.  7 - 9    best illustrate the components that are internal to the chamber  102 . The chamber boundary wall  106 , as shown, incorporates a well  126  that holds a rotating armature  128  in place. The armature  128  sits inside a bushing  130  inside the well to reduce friction. The well  126  also reduces the thickness of the boundary wall  106 . The armature  128  includes a square socket  132  that captures another internal square magnet  134  (best seen in  FIG.  9   ). Opposite the well, an axle  136  supports the rotation of the armature  128  on an axis perpendicular to the chamber wall  106 . The axle  136  is captured by a fixed mount  138  and a washer  140 . The mount  138  incorporates stops  142   a ,  142   b  that restrict the rotation of the armature  128  (see  FIG.  8   ). 
       FIG.  9    presents a simplified exploded view that shows the alignment of the rotational components of the assembly; both internal and external to the chamber  102 . The components below the boundary wall  106  are external to the chamber  102  and those above are internal. The boundary wall  106  is shown in cross section and shows the reduced thickness of the boundary wall at the bottom of the well  126  in which the internal components are seated. The motor gear  114  is shown for reference without the motor  112  that drives it. 
     Magnetic coupling is effected by the external magnet  120  and the internal magnet  134 . The poles of the magnets  120 ,  134  are parallel to the boundary wall  106 . In the diagram, they are shown in phase; the north and south poles of the external magnet  120  are aligned with the south and north poles, respectively, of the internal magnet  134 . This supplies the maximum attractive force normal to the boundary wall  106  with a net torque of zero about the center line (axis). 
     The external magnet  120  is captured by the square hole  118  in the magnet coupling gear  116 . As the magnetic coupling gear  116  is driven by the motor gear  114 , the magnet  120  is correspondingly rotated about the center line. The magnet adapter  122  is also located in the square hole  118 , adjacent to the magnet  120  and between the magnet  120  and the limit switch  124 . It is also square and rotates in correspondence to the magnetic coupling gear  116  and the magnet  120 . It serves to mate the square magnet  120  to the round button on the limit switch  124 . The magnet  120  and magnet adaptor  122 , while rotationally restricted, are free to move normal to the boundary wall  106 . 
     Inside the chamber  102  (above the wall  106 ), the internal magnet  134  is captured by the square socket  132  in the rotating armature  128 . The armature  128  is seated in the well  126  of the boundary wall  106  inside bushing  130 , which allows the armature  128  to rotate freely, in correspondence with the rotation of the internal magnet  134 . The armature  128  is secured at the surface opposite the boundary by the axle  136  and washer  140  held by the fixed mount  138 . This arrangement allows the armature  128  to rotate but restricts the movement of the armature  128  normal to the boundary wall  106 . 
     Turning to  FIGS.  10 A- 10 B , the behavior of the magnetic coupling is driven by the motor  112 , which rotates the motor gear  114 . The motor gear  114 , in turn, rotates the external magnet coupling gear  116 , which rotates the external magnet  120 . As the external magnet  120  rotates, it becomes out of phase with the internal magnet  134 . The force vector associated with the magnets  120 ,  134  is proportionally skewed from normal and develops a rotational component. The resultant torque increases as the phase angle increases. At some point, the torque increases enough to rotate the internal magnet  134  (See  FIG.  10 A ). The internal magnet  134  rotation drives the armature  128 , accordingly. 
     Rotation of the armature  128  is restricted by stops  142   a ,  142   b  (see  FIG.  8   ). Once the coupling is rotated to the point of contacting a stop  142 , the armature  128  can no longer rotate. At this point, the external magnet  120  continues to be driven, increasing the phase angle between the two magnets  120 ,  134 . When the phase angle increases to  90  degrees, the force vector becomes completely rotational; there is no force normal to the boundary. As the angle increases beyond 90 degrees, the force normal to the boundary reverses, becoming repulsive. At some point, the repulsive force become large enough to push the external magnet  120  away from the boundary wall  106  (see  FIG.  10 B ). The repulsive force is transmitted through the magnet adapter  122 . At some point, the repulsive force increases enough to force axial movement of the magnet  120  and magnet adapter  122  and activate the spring-loaded limit switch  124 . The activation of the limit switch  124  is detected electronically, and the motor  112  is stopped. 
     The motor  112  is then reversed via the electronics, which decreases the phase angle. As the phase angle decreases, the repulsive force decreases until it is nullified at the 90 degree phase angle. As the motor  112  (and external magnet  120 ) continues to rotate then the force becomes attractive and increases to its maximum at the zero degree phase angle. At some point, the external magnet  120  moves back toward the boundary wall  106  and releases the limit switch  124 . The motor  112  is stopped again, once the limit switch  124  is deactivated. 
     This reverse motion that is terminated with the release of the limit switch  124  is called the back-off period. When rotating the coupling towards one of the stops  142 , the external magnet  120  is intentionally over-rotated after the armature  128  is physically stopped. The over-rotation causes an increase in the phase angle. Since the limit switch  124  cannot be activated, except via a repulsive force between the magnets  120 ,  134 , the limit switch  124  is not engaged until the phase angle exceeds 90 degrees. The limit switch  124  activation marks the beginning of the back-off period, when the motor  112  is reversed. The limit switch  124  cannot be disengaged until the repulsive force is removed and the magnetic force transitions from repulsion to attraction. Therefore, the limit switch  124  is released when the phase angle is reduced to less than 90 degrees, which marks the end of the back-off period. At the end of the back-off period, the phase angle is such that the magnetic force vector holds the armature  128  against the boundary and against the stop  142 . Note that this assumes that the motor  112  and motor gear  114  are locked in position. 
     In alternative arrangements, the limit switch  124 , which operates to sense armature  128  position, could be replaced with a solid state sensor, such as optical or magnetic sensors. For example, for an optical sensor system the chamber boundary wall  106  separating the magnets  120 , 134  could be optically clear. There could be optical sensors ( 2 ) (not shown) located strategically at the hard stops inside the chamber  102 . The sensor could then pick up on the armature  128  inside being in position at the hard stop  142 . From a power resource view, even though these sensors are, themselves, consuming energy, it would actually be a win energy-wise because the limit switch  124  requires the motor  112  to be over-rotated to activate the limit switch and then the motor must be reversed to perform the back-off movement. The extra back and forth movement represents an additional 180+ degree movement that would not be required if using such an optical solid state sensor. Since the motor itself is a much larger consumer of energy, the extra movement is costly. Also, the sensors can be turned off until they are actually needed (i.e. just before the motor movement). On balance, using a solid state sensor may be a significant improvement energy-wise and time-wise, since the motor over rotation movement does take time. 
     As noted, the generic magnetic coupling system  100  described above is useful in any sealed chamber system where there is a need to reduce seal and friction between moving parts. Further exemplary coupling systems are described below in connection with the piloted valve system  200  and the oscillator/diverter assembly  300 . 
     Referring now to  FIGS.  11 - 16   , there is shown and described an exemplary pressure control valve assembly  200  controlled by magnetic coupling assembly  204  having the operational characteristics as generally described hereinabove. 
     The pressure control valve  200  adjusts the water pressure delivered to the spray nozzle  14 . The distance of the spray is proportional to the pressure. In the exemplary system, the valve  200  is controlled by a motor  202 , making it capable of being controlled algorithmically by microprocessor  22 . The system  200  incorporates pressure sensor  400  located adjacent the nozzle  14 , which allows the system to operate as a closed loop with respect to water pressure. 
     The basis of the control valve  200  is a pilot valve  206  which is used to control the water pressure delivered to the sprinkler head  14 . The pilot valve  206  may comprise three chambers: the input chamber  208 , the output chamber  210  and the control chamber  212  (see  FIGS.  13 - 14   ), attached to the top of a valve seat  214 . The input chamber  208  is supplied with water through an input port  216 . The pressure in the input chamber  208  is always the maximum pressure, which is referred to as the supply pressure. The output chamber  210  is vented to the atmosphere via an outlet  218  and, ultimately, to the spray nozzle  14 . Atmospheric pressure is considered the zero pressure. 
     When the valve  200  is closed, the pressure in the output chamber  210  is zero. 
     When the valve  200  is open, there is, typically, back pressure due to the relatively narrow orifice of the nozzle  14 . Therefore, the output pressure may be greater than zero, but is always less than the supply pressure. 
     The primary flow of water flows between the input chamber  208  and the output chamber  210  directly when the valve is open. A secondary flow path is through the control chamber  212 , which is separated from the input/output chambers  208 ,  210  by a flexible diaphragm  220  that incorporates into it a rigid stabilizer  222 . The stabilizer  222  is connected to the diaphragm  220  by a plurality of circumferentially spaced posts  223  (only one visible) which are press fit through corresponding holes  225  in the diaphragm  220 . Four points of connection provide higher rigidity to the diaphragm  220 , prevent vibrational instability caused by water flow and allow the valve to stabilize in the desired position more quickly. 
     Water flows into the control chamber  212  through an input pilot hole  224 , which is always open. Pilot hole  224  extends through one of the connection posts  223 . The water flows from the control chamber  212  to the output chamber  210  via an output pilot hole  226 , which may be opened or closed by a plug  228 . 
     The benefit of the pilot valve arrangement is that a very small amount of energy is necessary to open or close it. The control input is a matter of opening or closing the output pilot hole  226  using the plug  228 . The amount of energy involved is very small because the force necessary is a product of the very small area of the output pilot hole  226  and the pressure differential between the control chamber  212  and the output chamber  210 . Once the pilot hole  226  is opened or closed, the primary flow of water between the input chamber  208  and output chamber  210  is affected by the position of the diaphragm  220 , which is a function of the force differential on the two sides of the diaphragm  220 . On one side of the diaphragm  220 , the force is a product of the area of the diaphragm  220  and the pressure in the control chamber  212 . On the other side, the total force is the sum of the force on the area adjacent to the input chamber  208  and the force adjacent to the output chamber  210 . Note that the area adjacent to the input chamber  208  is significantly larger than the output area. 
     When the plug  228  is blocking the output pilot hole  226 , the input pilot hole  224  causes the input chamber  208  and control chamber  212  to equalize, so the forces on both sides of the diaphragm  220  corresponding to the input area are equal. Since the output pressure is always less than the supply pressure, the area adjacent to the output chamber  210  is less than the corresponding area in the control chamber  212 . This differential causes the diaphragm  220  to press toward the output port  218 , restricting water flow and, ultimately, closing and sealing the output port  218 . When the plug  228  is not blocking the output pilot hole  226 , the pressure in the control chamber  212  equalizes with the output chamber  210 . In this state, the force on both sides of the diaphragm  220  adjacent to the output area is equal. Since the control chamber pressure is less than the input chamber pressure, the force on the area adjacent to the input chamber  208  is larger on the input chamber side and the diaphragm  220  is pushed away from the output port  218 , allowing more water to flow. Note that when the diaphragm  220  is fully open, there is necessarily a pressure differential between the supply pressure and the control/output pressure because it is the differential that is holding the diaphragm open. That means there is a small loss of pressure when using this type of valve. 
       FIGS.  12 - 14    show the full valve assembly  200  with the pilot valve mechanism at the bottom with its input port  216 . The basic function of the pilot valve chambers  208 ,  210 ,  212  and diaphragm  220  is conventional in the art. However, the method of controlling the valve  200  is unique. The control chamber  212  is comprised of two parts  212   a ,  212   b , as shown, and encompasses the control components of the valve. The external drive for movement of the plug  228  is supplied via a magnetic coupling  100  generally as described hereabove, the external parts of which are shown and include motor  202 , stand  230 , drive gear  232 , magnetic coupling gear  234 , external magnet  236 , magnet adapter  238  and limit switch  240 . The internal parts of the magnetic coupling  100  drive a control mechanism  242  that results in the plug  228  moving normal to the output port of the diaphragm  220 . 
       FIG.  15    shows the control mechanism  242  internal to the control chamber  212 . 
     The mechanism  242  is driven rotationally by the external magnet  236  ( FIGS.  12 - 14   ), causing an internal magnet  244  to rotate, accordingly. The internal magnet  244  is captured in a square socket at the top of a magnet adapter  246 . The magnet adapter  246  rotates within bushings  248  and  250  at top and bottom respectively inside a cylindrical void in the control chamber housing  212  ( FIG.  14   ). The magnet adapter  246  incorporates slots  252  that trap a control arm  254  that is embedded radially in a threaded leadscrew  256 . The leadscrew  256  engages a nut  258  that is captured by the control chamber housing  212 . Two bushings  260   a ,  260   b  provide the bearing surface between the rotating magnet adapter  246  and the stationary nut  256 . The bottom of the leadscrew  256  incorporates a flange  262  around which the rubber plug  228  is molded. A leadscrew guide  264  ensures the plug  228  is centered on the output pilot hole  226 . It also serves to lock the diaphragm  220  in place in the pilot valve mechanism. Note that it is stationary. 
     The pilot valve control mechanism  200  operates in the same manner as the magnetic coupling mechanism  100  described hereinabove. The external motor  202  drives the external magnetic coupling gear  234  and external magnet  236 , which then drives the internal magnet  244 . The square magnet  244 , being trapped in a square socket rotates the magnet adapter  246 , which rotates the leadscrew  256  via the control arm  254 . As the leadscrew  256  turns in the trapped nut  258 , it moves up and down relative to its rotational axis. This causes the plug  228  to unblock and block the output pilot hole  226 , accordingly. When the pilot hole  226  is unblocked, the diaphragm  220  rises and increases water flow through the valve  200 . When the diaphragm  220  rises and contacts the plug  228 , the pilot hole  226  is blocked, and the diaphragm  220  is pushed back down by the control chamber pressure and the water flow decreases. As equilibrium is reached, the resulting behavior is that the diaphragm  220  follows and is positioned by the control mechanism  242 . This allows the external motor  202  of the magnetic coupling arrangement  204  to effectively control the water flow through the valve  200  and, ultimately, the water pressure delivered to the sprinkler nozzle  14 . 
     The pressure control valve  200  uses the magnetic coupling  204  for the control input and includes limit switch  240  as also described above. The limit switch  240  is not used to control the variable pressure, but it is used to ensure that the valve  200  is closed. When the leadscrew  256  is driven all the way to the closed position then it can no longer rotate. The external magnet  236  will continue to rotate and the magnets  236 ,  244  will become out of phase. Eventually, the phase angle will become large enough to force an axial repulsion and activate the limit switch  240 , which will be detected, indicating that the valve  200  is completely closed. Likewise, when opening the valve  200 , activation of the limit switch  240  will occur when the valve is opened to its mechanical limit. 
     An interesting benefit to this arrangement is that pilot valves require a minimum amount of pressure to stay closed. For example, if you connect one to a water supply that is off and then turn the supply on, you will typically get a short burst of water and then the valve will seal. That does not happen with this implementation because the leadscrew  256  mechanically holds the diaphragm  220  closed. 
     With respect to the use of alternate sensors in the pressure control valve  200 , which uses a lead screw  256 , it would make sense to keep the limit switch  240  because the hard stops are only used to detect closing the valve and opening it to its maximum travel. However, it could still benefit from using an optical sensor, though. For example, if the control chamber  212  has an optically clear window then the lead screw travel could be monitored by an encoder. That is typically implemented by including lines on the shaft that can be counted by the sensor. This allows for tracking exactly how much the screw has rotated inside the chamber. 
     While the present pressure valve embodiment  200  is illustrated and described as being controlled by a motor assembly  202 , the valve  200  could be manually controlled or controlled by other actuators. For example, a manually controlled pilot valve assembly  200  (without motor or without motor and gears, i.e. manually rotating the external magnet itself) could find use in other applications as a conventional faucet valve or spigot (not shown). 
     Turning now to  FIGS.  16 - 23   , there is illustrated and described an oscillator/diverter assembly  300  which is based on a water turbine rotation mechanism wherein the position of a diverter arm is electronically controlled by a magnetic coupling mechanism  304  in accordance with the above teachings. The assembly  300  generally includes drive motor  302 , the magnetic coupling assembly  304 , a diverter assembly  306  and an oscillator drive assembly  308 . 
     The oscillator drive portion  308  is a water powered turbine motor that rotates a shaft  310  and neck  312  to which spray nozzle  14  is secured. The rotation thereby provides the ability to direct spray in different directions. The oscillator drive portion  308  incorporates an assembly of components that allow the drive to reverse the direction by directing the flow of water in one of two orientations causing a turbine wheel  314  to rotate in one of two directions, accordingly. The turbine wheel  314  provides the rotational input force to the water powered motor, so reversing the turbine direction also reverses the motor direction. The assembly which is used to change the motor direction is, therefore, the diverter assembly  306 . 
     The diverter assembly  306  allows the direction change to occur as a result of electrical input to the reversible electric motor  302 . The electric input is controlled by electronics, which allows the direction of the oscillator  308  to be controlled via electronic input, including microprocessor control. An additional benefit of this type of control is that the diverter  306  includes a neutral or idle position. That is, the water flow can be directed equally to both sides of the turbine wheel  314 , creating a net zero force in either direction causing the water powered motor to stop. It is also possible to control the speed of the water flow in either direction, thereby providing the ability to use the diverter  306  as a speed control for the water powered motor. 
       FIGS.  16 - 18    shows various views of entire oscillator/diverter  300  for reference including a transparent elevation view. 
     The input to the assembly, as shown, is a standard threaded garden hose connector  316 , although it could be any suitable connector or integrated directly into a common housing downstream of the pressure control valve. This is the supply pressure. Varying this pressure with the pressure control valve  200  affects the output pressure of nozzle  14  and, thus, the distance of the water sprayed from the nozzle  14 . Varying the supply pressure will also affect the speed of the water powered motor and a minimum pressure must be supplied for the motor to turn. 
     The flow of water initially passes into a diverter chamber  318  through an input port  320  and is directed through one of two exit ports  322 ,  324  in a boundary wall  326  between the diverter chamber  318  and a turbine chamber  328  in the oscillator drive portion  308 . The water flows across and rotates the turbine wheel  314  (assuming the diverter is not in the idle position). The water then flows through another boundary wall  330  into an oscillator chamber  332  containing a gear train  334 . The nozzle (not shown) is mounted to the neck  312 . 
     There is also a pressure relief valve  338  that provides an alternative path directly from the diverter chamber  318  to the neck  312  for water at excessive supply pressures that might, otherwise, overwhelm the diverter/oscillator  300 . The pressure relief valve  338  essentially acts as a rotation speed limiter without restricting nozzle pressure. Note that restricting the nozzle pressure would restrict the maximum distance of the spray pattern. 
     The sprinkler head gear  336  also drives a rotational sensor gear  340 , which captures a diametric permanent magnet in line with a magnetic rotational sensor  500  located external to the oscillator/diverter assembly  300 . The gear  340  has a 1:1 ratio with the head gear  336 , making it possible to electronically determine the corresponding angle of rotation of the nozzle  14 . The oscillator gear train  334 , head gear  336 , sensor gear  340  and pressure relief valve  338  are all rotatably captured within the oscillator chamber  332 , which is pressurized at the output (nozzle) pressure. The electronic pressure sensor  400  is embedded in the side wall of the oscillator chamber  332  and provides a means of electronically determining the nozzle pressure in real time. Note that the shaft  310  of neck  312  is the only component of the oscillator/diverter assembly  300  that penetrates a water chamber to atmosphere with a rotating component and, therefore, requires a seal; supplied here by an O-ring  344 . Other than the supply input  320  and the shaft  310 , the entire device is hermetically sealed. The friction introduced by the O-ring seal  344  is easily overcome by the torque produced by the gear ratio (approximately 500:1) of the oscillator drive train  334 . 
       FIGS.  18 - 20    show external views of the diverter components. The motor  302  of the external portion of the magnetic coupling  304  is used to drive the mechanism. The external rotation is transferred to the internal portion of the assembly, which includes an armature  346  that diverts the water flow through one of two ports  322 ,  324  into the turbine chamber  328 . 
     The input water flow is through input port  320 . This supplies water under pressure to the diverter chamber  318 . The control input is via the external components of the magnetic coupling  304 , which changes the position of the armature  346  ( FIGS.  20 - 23   ) inside the diverter chamber  318 . The position of the armature  346  determines which port  322 ,  324  the water flows through into the turbine chamber  328 . As the water flows across the turbine wheel  314  the water continues to flow through the boundary wall  330  into the oscillator chamber  332  via ports  333 . The turbine  314  rotates and provides the mechanical input to the gear train  334  via a small drive gear  348 . A relief valve port  350  further allows excess pressure to release water through to the sprinkler neck  312 , limiting the speed of the turbine  314 . 
       FIGS.  20 - 21    shows the control input into the diverter armature  346 . The motor gear  352  drives the magnet gear  354 , which has a square hole that captures the external magnet  356 . The external magnet  356  is magnetically coupled to the internal magnet  358  across the boundary wall of the diverter chamber  318 . The diverter boundary wall has a round well  360  incorporated into it that captures the armature  346 . As the external magnet  356  is rotated, the internal magnet  358  is rotated accordingly. Since it is captured in a square socket in the armature  346 , the armature  346  is also rotated in correspondence with the magnetic coupling. When the magnets  356 ,  358  are in phase, the north and south pole of the external magnet  356  is aligned with the south and north poles of the internal magnet  358 . In this relative position, the magnetic force vector is entirely normal to the boundary and the magnets are attracted to each other. As the motor gear  352  continues to rotate, the armature  346  contacts one of the stops  362   a ,  362   b , preventing any further rotation of the armature  346 . As the external magnet  356  continues to rotate, the magnets become out of phase. When they are out of phase by 90 degrees, there is no longer a net magnetic force normal to the boundary, so the force vector is entirely rotational. As the external magnet  356  continues to rotate putting it greater than 90 degrees out of phase 
     with the internal magnet  358 , the magnets begin to repel each other. As described previously, the external magnet  356  is free to move normal to the boundary, so it is pushed away from the boundary and transfers the repulsive magnetic force through the magnet adapter  364  to the limit switch  366 . At some point, when the phase angle is between 90 and 180 degrees, the force becomes strong enough to activate the limit switch  366 , which is electronically detected. Upon the detection, the motor  302  is stopped and then reversed, which causes the phase angle to decrease. At some point, when the phase angle is less than 90 degrees, the magnetic force becomes attractive again and the magnet  356  moves back toward the diverter boundary, releasing the limit switch  366 . Again, the deactivation of the limit switch  366  is detected electronically, and the motor  302  is stopped and locked. At this position, the phase angle is, generally, still greater than zero. In the figure, the external magnet  356  is shown to be 45 degrees out of phase with the internal magnet. In this state, the magnetic force vector is holding the armature  346  against the diverter boundary and against the stop  362 , which is situated as to locate the armature plug  368  over one of the output ports  322 ,  324  to the turbine chamber  328 . 
       FIGS.  21 - 23    show the armature  346  being held in position against a stop  362 , which holds the armature plug  368  in line with one of the ports  322 ,  324  (blocking the port) into the turbine chamber  328 . Blocking one port causes the water to flow into the opposite port. The pressurized water is directed onto the blades of the turbine  314  through the corresponding port outlet. In this figure, the turbine  314  would rotate counter-clockwise, as viewed from above. Rotating the armature  346  to the opposite stop would cause the plug  368  to block the opposite port, which would cause water to flow through the other port and the turbine  314  would rotate in the clockwise direction. It is this mechanism that allows the rotation direction of the oscillator to be controlled electronically. Note that it is possible to turn the motor  302  so that the armature  346  is in a position midway between the ports (position not shown). In this state, the water flows equally between the two ports  322 ,  324  and the net pressure at the two port outlets is approximately the same and the turbine  314  does not rotate. One exemplary method of achieving this state is by measuring the time it takes to drive the motor  302  from one stopped position to the other and then by rotating the motor  302  from one stopped position toward the other for half of that duration. Thus, the control is able to effect three states: rotation clockwise, rotation counter-clockwise and stationary. Other possible methods include the use of artificial intelligence (AI) learning algorithms which learn and adjust motor timing. AI type learning algorithms are effective for this type of implementation because of the unpredictable nature of water in mechanical systems. 
     Another benefit to the present smart sprinkler arrangement is that the sprinkler system will never get stuck due to low water pressure. One problem with purely mechanical sprinklers is that they require a minimum water pressure to operate. There is friction in the water motor mechanism, so you have to turn up the water pressure to some minimum amount to overcome that or it won&#39;t rotate. It can even be hard to predict because that point can be a little different along the rotation. Also, the mechanical actuator for changing direction requires an even greater pressure to overcome the force involved in moving the actuator. Moreover, the supply pressure can change, so that a drop in pressure can cause a sprinkler to stop rotating even if it was when it was set up. 
     The present system has the same problem with friction of the water powered motor  308 . Some minimum is required for rotation of the turbine wheel  314  to occur. With the present sprinkler system  10 , the point of direction change is detected by a sensor and the change of direction is accomplished via an electric motor. Neither introduces additional friction or requires water pressure. In addition, it can detect whether the sprinkler head is rotating (rotational sensor gear  340 ) and can automatically raise the pressure (valve  200 ) until it starts rotating. It also raises the pressure automatically if the supply pressure drops due to outside factor (local water demand). This means that the sprinkler  10  will not get stuck. In fact, there really is no minimum pressure. The system will lower the pressure to a user set point and then automatically raise it enough to rotate the sprinkler head  14 . Once rotation is detected, it will again lower the pressure to the user set point. The system won&#39;t generate a simple arc in this mode, as it would with a higher pressure, but it will apply water at the set range, and it won&#39;t get stuck. Note that this assumes that the supply pressure is greater than the minimum required pressure. If this is not satisfied, the sprinkler can detect the condition and shut itself off completely, abandoning the user pattern until such time as the supply pressure is restored. Similarly, if a water pattern was configured that includes a maximum water pressure that cannot be achieved at the time of running the pattern, the sprinkler can automatically skip over 
     those portions of the pattern that cannot be achieved and still execute the portions of the pattern that can. Thus, the sprinkler can come as close to satisfying the desires of the user as is possible. 
     Accordingly, it can be seen that the present system  10  provides several unique and novel improvements over systems of the prior art, particularly with respect to sealed chamber magnetic couplers and switching mechanism which eliminate the need for high friction seals for rotating parts and which also reduce power needs for rotating components within the sealed chambers. 
     Location Awareness 
     In the present system  10 , the user is given the ability to create and store patterns that the control system  22  will be able to follow in a repeatable and predictable manner. Since the two control mechanisms involve sensory awareness and control of distance (proportional to water pressure) and rotational angle, repeatability requires specific location and orientation calibration. 
     The system  10  uses a positionable mounting base to implement this functionality. 
     Referring to  FIGS.  24 - 25   , there is a base  400  having a body  402  that is configured to be secured with spikes or other, semi-permanent fasteners, to the ground so as to fix the base  400  at a predetermined location. The base  400  includes a plurality of mounting feet or tabs  404  extending radially outwardly from the body  402  each with a bore  406  therethrough to accept spikes (not shown). The base  400  further incorporates a keyed mortise  408  on its top surface designed to receive a matching keyed tenon  412  on the sprinkler housing  410  to insure proper alignment of the sprinkler unit with the base  400 . In the exemplary embodiment, the mortise and tenon are each generally circular with a single flat surface for rotational orientation. Other interfitting mated alignment structures are also contemplated. With this arrangement, the sprinkler system  10  can be reliably placed on the base  400  in a specific location and rotational orientation. If the base is not moved, any patterns created with the sprinkler on the base can be run repeatedly and reproduce the same result. 
     Moreover, any number of a plurality of bases such as  400 ,  400 ′ and  400 ″ may be located on the ground to provide a plurality of defined coverage areas, and repeatability 
     of each of the pre-programmed coverage patterns for the respective coverage areas will be maintained, so long as the pattern being run was created on the particular base and is selected for operation on the associated base. In this way, a plurality of bases  400  allows for a corresponding expansion of the useful geographic range of the sprinkler system  10 . 
     In order to provide automated “awareness” of location and selection of a predetermined sprinkler pattern for that location, each base incorporates an RFID tag  414  (See  FIGS.  24 - 25   ), which is a passive electronic component requiring no electrical power in its idle state. The lower portion of the sprinkler housing  410  incorporates an RFID reader (antenna TX/RX)  416  that is aligned with the RFID tag  414  when the sprinkler housing  410  is placed on any given base ( 400 ,  400 ′,  400 ″). A corresponding antenna within the RFID tag allows a transmitted signal from a nearby electronic circuit (reader  416 ) to energize the passive RFID tag  414  and to read its unique identifier. Once the identifier is known, the system software can automatically relate the identifier to a known base and, therefore, to a known location and an associated pattern, or collection of patterns, saved in memory. This alleviates the burden on the user of manually associating the pre-programmed patterns with the individual bases. 
     It should also be noted that the system  10  can also detect the condition where the sprinkler is not on any base and can, therefore, detect the eventuality of the sprinkler being placed on or taken off a base. This allows an associated pattern to be automatically initiated when the sprinkler is placed on a particular base. Conversely, a running pattern may be interrupted when the sprinkler is removed from a base and resumed when placed back on the same base. 
     An analogous ID system could be implemented using barcodes or other unique identifier schemes, but the RFID tag is much more robust for this particular use scenario. 
     Gesture Support 
     The exemplary embodiment of the present sprinkler system  10  has no mechanical features on the physical device for manually controlling any aspect of the water spray. Rather, the system  10  is designed to use a separate device  20  as a user interface with all control input being transmitted from the user interface device  20  to the sprinkler  10  over a communication interface. 
     In some embodiments, in order to provide a manual input scheme that can be used without the communication interface  34 , the sprinkler may include an accelerometer  500  (2 axis or 3 axis) to facilitate certain device functions without the need for the user interface device (see  FIG.  1    block diagram scheme). 
     Accelerometer  500  is a well-known electronic component that may be affixed to the internal structure of the housing  410  or directly mounted to an internal circuit board. The accelerometer  500  allows instantaneous detection of the orientation of the sprinkler housing  410 . Software algorithms are used to interpret real time changes in orientation as “tilt” gestures. Various tilt gestures can be distinguished for the purpose of interpreting user intent and thus provide a reliable manual input regarding desired function without externally facing switches. 
     Some examples follow: 
     If the sprinkler is off, then a rocking or rotating motion of the housing  410  while the sprinkler is not on a base (see RFID above) then it may be assumed that the user wants to turn on the water for use in a manual mode (i.e., not running a pattern). The control would then open the pilot valve to a predetermined position. A similar or same rocking motion can be interpreted as user intent to turn the water back off 
     If the water is on in this manual mode, then turning the sprinkler sideways could indicate a desire to turn off the water temporarily. For instance, the user may lay the sprinkler on its side on the ground. Returning the sprinkler to its upright position could then be interpreted as resuming water flow. 
     Also while the water is on in manual mode, a sudden impact, i.e. tapping or bumping the sprinkler housing against an opposing hand could be interpreted to increase water flow from a lower to a higher flow or vice versa. 
     Other combinations of orientation changes, insofar as they are identifiable, could be mapped to other functionality, such as rotating the sprinkler nozzle to a different rotational angle. 
     Having thus described certain particular embodiments of the invention, it is understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description, as many apparent variations thereof are contemplated. Rather, the invention is limited only by the appended claims, which include within their scope all equivalent devices or methods which operate according to the principles of the invention as described.