Smart irrigation sprinklers

An improved automated irrigation system having localized moisture needs input to the control function. There is a sprinkler head connected to a supply of water under pressure by a pipe having a valve therein. A moisture sensing probe is placed in the soil adjacent the sprinkler head for developing an electrical signal representing the moisture content of the soil surrounding the probe. There is irrigation bypass logic disposed at the probe and operably connected to the valve and the probe for comparing the moisture content of the soil surrounding the probe to pre-established limits and for preventing the valve from supplying water to the sprinkler head when there is sufficient moisture in the soil. A timer controller can be employed to provide operating power to the system only at preferred times for watering. The moisture parameters for watering are adjustable. There is a wirelessly connected version eliminating wires between the probes and the valves. Supplemental valves are employed in branch lines and riser pipes to give more accurate control over localized areas and planting. Preferred power is supplied by a rechargeable battery recharged by a solar panel. There is apparatus for optimally adding fertilizer to the irrigation water as part of the moisture controlled system or on a stand-alone basis.

BACKGROUND OF THE INVENTION 
The present invention relates to controllers for irrigation sprinklers and, 
more particularly, to an improved automated irrigation system having 
localized moisture needs input to the control function comprising, a 
sprinkler head connected to a supply of water under pressure by a pipe 
having a valve therein; moisture sensing probe means placed in the soil 
adjacent the sprinkler head for developing an electrical signal 
representing the moisture content of the soil surrounding the probe means; 
and, irrigation bypass logic means disposed at the probe means and 
operably connected to the valve and the probe means for comparing the 
moisture content of the soil surrounding the probe means to 
pre-established limits and for preventing the valve from supplying water 
to the sprinkler head when there is sufficient moisture in the soil. 
Irrigation sprinkler systems tend to undergo little improvement with time 
and that progress which is made is mostly an adapting of new materials to 
old processes. Thus, the design of sprinkler heads originally fabricated 
out of metals has been copied in plastics. Likewise, the control functions 
originally accomplished with clock motors, cams and switches has now been 
copied with electronics. The result, in most cases is a system which looks 
"state-of-the-art" to the consumer but which, in fact, falls far short of 
providing adequate control of the irrigation function for the areas being 
watered by the system. This is true for both the small home user and the 
large commercial users such as golf courses, and the like. A typical 
blatant and irritating indication of the failure of these supposedly 
state-of-the-art irrigation control systems is seeing the sprinklers in an 
area operating in the rain during a drought. Not only that, most 
individuals do not known how to water plants properly. They either water 
too much or not enough. They also water in a manner which does not promote 
adequate root growth. As a result, in any water deprivation situation, the 
plants quickly die. With the conventional irrigation control system, it is 
these very people who program the controller. Since they don't know how to 
water, they simply set up the controller to water in the same wrong manner 
and assume that now that their irrigations have been turned over to the 
automated device, they no longer have to worry. Of course, when the plants 
die, they blame the irrigation system. 
The typical approach to irrigation as employed in most control systems is 
depicted in FIGS. 1-3. An input pipe 10 connected to a source of water 
under pressure is connected to a plurality of valves 12 (only one being 
shown for simplicity) at a main site such as a garage, clubhouse, building 
basement, or the like. A controller 14 is placed adjacent the valves 12 
and operably connected thereto with wires 16. The controller 14 is 
connected to an appropriate source of power (not shown), which is the 
reason that the controller 14 and valves 12 are all placed close adjacent 
the main site. Since multiple conductor wire as typically employed for the 
wires 16 is costly and a bother to bury in trenches between the controller 
14 and valves 12, they are usually located within feet of each other. Each 
valve 12 has a branch pipe 18 connected thereto which extends from the 
main site to a remote site where there are to be a plurality of sprinkler 
heads 20 attached to riser pipes 22 connected into the branch pipe 18. In 
a typical yard for a home, the branch pipes 18 only extend 50-100 feet 
typically. In a golf course, or the like, they can extend by orders of 
magnitude. 
Again, it is also typical that the sprinkler system is installed with 
virtually no relationship to the type of plants that are to be irrigated 
thereby. Even in high priced landscaping undertakings like golf courses, 
hotel grounds, etc., the landscaping is done by one entity and the 
irrigation system is installed by another entity with only a rough layout 
map to work from. It is generally assumed by all concerned that if the 
area is covered by a grid of sprinkler heads 20, the state-of-the-art 
irrigation control system will have no problem in properly watering the 
area. Nothing could be further from the truth. Once the landscaping has 
been completed and the operation of the system has been turned over to 
others, the failure of the system does not become apparent immediately. 
Rather, there is a continuous and insidious replacement of plants which 
have died--because of everything but the irrigation system. In the rare 
case where the failures of the irrigation system are recognized, the cost 
and inconvenience of digging up the old system and reinstalling it are 
generally a deterrent to actually accomplishing a meaningful modification. 
The management of an operating golf course is not about to shut the place 
down and allow trenches to be cut through the fairways to relay irrigation 
pipe. Thus, sprinkler heads 20 may be replaced and "adjusted" to vary flow 
rates and the watering times for the controller 14 may be varied; but, the 
system will not be made to work properly. Various plants with differing 
watering requirements being watered from a common branch pipe 18 will have 
to suffer (and probably die). Either some will be over watered or some 
will be under watered. 
There has been some recognition in the art that it is stupid to operate the 
sprinkler system when it is raining (or has rained recently). Most 
controllers 14 have a "rain switch" that can be placed in a "rain" 
position when the operator knows that rain will take care of the 
irrigation for a given period. The rain switch merely disconnects the 
connection to the wires 16. In other regards, the controller 14 continues 
to operate. If the operator forgets to set the switch, the irrigation 
system operates anyway (including during a downpour). If the operator 
forgets to return the switch to its operating position, nothing gets 
watered at a later date and dries up. For the homeowner, this means having 
to have a "controller sitter" for the irrigation system when on vacation. 
It also means trudging through the rain and wet grass to turn off a 
controller mounted on the outside of the house that is watering the lawn 
during the rain. 
Some controllers 14 have a series connection (like the above-described rain 
switch) to which a "rain sensor" can be operably connected. The typical 
rain sensor is a pan with a float connected to a switch. When it rains, 
the pan fills with water. If there is sufficient water in the pan to cause 
the float to operate the switch, the irrigation system is disconnected 
from the valves 12. A more exotic variation of that prior art approach is 
depicted in FIG. 2. In this case, a moisture sensor probe 24 is inserted 
in the ground to test the moisture content thereof. For the reasons set 
for above relative to running wires between components, the probe 24 is 
placed close to the controller 14 or the valves 12, whichever is most 
convenient. This prior art approach presupposes that the moisture content 
of the soil where the probe 24 is located is a proper indication of the 
moisture content of the soil throughout the system. Except in rare 
instances, that is a brash assumption which can lead to improper watering 
and, once again, dead plants. 
It should also be mentioned in passing that some commercial irrigation 
systems provide a tank 26 for containing liquid fertilizer. The tank 26 is 
connected to the branch pipes 18 (or the input pipe 10) by a connecting 
pipe 28. A manual or automated valve (not shown) can be opened to allow 
the fertilizer to be mixed with the irrigation water and thereby fertilize 
the plants. Such systems are quite common for systems used in the 
irrigation of crops and hydroponics. Simple versions of this approach are 
also available for the home waterer, and the like. The mixer/dispenser 
connects to a hose bib and the hose is connected to the mixer/dispenser. 
Fertilizer pellets (or liquid) is placed in the mixer/dispenser which 
causes the fertilizer to be mixed with the water coming out of the hose. 
Wherefore, it is the object of the present invention to provide an 
irrigation system which accurately controls the irrigation of areas as a 
function of the moisture content of the soil of the area. 
It is another object of the present invention to provide an irrigation 
system which can be employed to retrofit existing irrigation systems with 
a minimum of inconvenience. 
It is still another object of the present invention to provide an 
irrigation system which can easily adapt to the special watering needs of 
different plants within a given area. 
It is yet another object of the present invention to provide an automated 
irrigation control system which can be added to present manual systems 
with a minimum of modification and digging. 
It is a further object of the present invention to provide an irrigation 
system which includes fertilizing capability which can easily adapt to the 
special needs of different plants within a given area. 
Other objects and benefits of the present invention will become apparent 
from the description which follows hereinafter when taken in conjunction 
with the drawing figures which accompany it. 
SUMMARY 
The foregoing objects have been achieved by the improved automated 
irrigation system of the present invention having localized moisture needs 
input to the control function comprising, a sprinkler head connected to a 
supply of water under pressure by a pipe having a valve therein; moisture 
sensing probe means placed in the soil adjacent the sprinkler head for 
developing an electrical signal representing the moisture content of the 
soil surrounding the probe means; and, irrigation bypass logic means 
disposed at the probe means and operably connected to the valve and the 
probe means for comparing the moisture content of the soil surrounding the 
probe means to pre-established limits and for preventing the valve from 
supplying water to the sprinkler head when there is sufficient moisture in 
the soil. 
In the preferred embodiment, the valve is an electrically operated valve 
and there are, additionally, timer controller means for supplying power to 
the valve only at pre-selected times and adjusting means for adjusting the 
pre-established limits to suit the particular watering needs of the area 
into which the probe means is placed. 
In one embodiment wherein the valve is an electrically operated valve 
operated by timer controller means connected for supplying power to the 
valve only at pre-selected times, wireless operation is provided by 
receiver means disposed at the timer controller means for receiving a 
radio frequency signal and for not supplying power to the valve in the 
presence of the radio frequency signal and transmitter means disposed in 
combination with the probe means for transmitting the signal when there is 
sufficient moisture in the soil. Where there are a plurality of valves 
connected to the timer controller means in the wireless version, there are 
identification code recognition means included within the receiver means 
disposed for disabling only the valve associated with an identification 
code appended to the radio frequency signal and identification code 
addition means included within the transmitter means for appending a 
unique identification code associated with the valve controlling the 
associated sprinkler head to the radio frequency signal when transmitting 
the signal. 
In one variation, supplemental valve means are disposed in a pipe supplying 
water to one or more sprinkler heads and operably connected to the 
irrigation bypass logic means for operation thereby whereby the flow of 
water to the individual sprinkler heads is stopped when no water is needed 
in the area watered thereby. In a variation of that approach, the 
supplemental valve means is disposed in a riser pipe directly connected to 
a single sprinkler head. For use by governmental agencies along freeways 
and in other commercial applications wherein the riser pipe and the 
sprinkler head include quick disconnect coupling means for releasably 
connecting the sprinkler head to the riser pipe, the supplemental valve 
means also includes quick disconnect coupling means for releasably 
connecting the supplemental valve means between the sprinkler head and the 
riser pipe. 
In the preferred embodiment, there are rechargeable battery means for 
supplying power to the irrigation bypass logic means and solar panel means 
for recharging the battery means. 
In a unitary embodiment, there is a valve body containing the irrigation 
bypass logic means and having the probe means extending therefrom, the 
valve body having an inlet opening for receiving the water under pressure 
and an outlet opening having the sprinkler head connected thereto and 
supplemental valve means disposed in the valve body between the inlet and 
outlet openings and operably connected to the irrigation bypass logic 
means for operation thereby whereby the flow of water to the sprinkler 
head is stopped when no water is needed in the area. 
For automatically adding fertilizer to the irrigation water on a locally 
optimized basis, there is a valve body having a bore therethrough 
extending between an inlet opening for receiving the water under pressure 
and an outlet opening having the sprinkler head connected thereto, the 
valve body further having a compartment for holding concentrated 
fertilizer with a first conduit connecting between the compartment and the 
bore adjacent the outlet opening and a second conduit connecting between 
the compartment and bore adjacent the inlet opening; valve means disposed 
in the first conduit for opening and closing the conduit; mechanical timer 
means operably connectable for operating the valve means for a 
pre-established period of time; means for operating the timer from the 
movement of water through the bore; disconnect means for selectively 
activating an operating connection between the timer means and the valve 
means; and, operation counting means for counting the number of times 
water pressure appears in the bore and for causing the disconnect means to 
activate the operating connection between the timer means and the valve 
means every time water pressure has appeared in the bore a pre-established 
number of times whereby fertilizer contained in the compartment is added 
to irrigation water flowing through the bore through the first conduit for 
the pre-established period of time every time water pressure has appeared 
in the bore the pre-established number of times.

DESCRIPTION OF THE VARIOUS EMBODIMENTS: 
In its simplest embodiment, the present invention comprises the arrangement 
shown in FIG. 4. This embodiment is suitable for retrofitting an existing 
system with a minimum of disturbance and requiring no digging at the 
watering sites whatsoever. The original controller 14 is replaced with a 
new controller 14'. Otherwise, the remainder of the system remains as 
described with respect to FIG. 1. One or more wirelessly transmitting 
probes 24' are inserted in the ground at the remote site where the 
sprinkler heads are located. The controller 14' is functionally described 
in FIG. 9. The typical prior art control functions are provided at 30. The 
outputs from the control functions 30 to the wires 16 have series switches 
32 therein in the same manner as the prior art "rain switches" described 
above. The switches 32, however, are operably connected to receiving logic 
34 which, in turn, is connected to the antenna 36. Each of the switches 32 
has a "station identification number" associated therewith. Turning now to 
FIG. 10, a typical probe 24' is shown in functional block diagram form. 
The probe 24' in its preferred form is controlled by logic 38. Logic 38 
receives inputs from two sources. First, is from the probe elements 40. 
Moisture sensing probes are known in the art and, therefore, the workings 
thereof will not be described in detail herein in the interest of 
simplicity and the avoidance of redundancy. For the purposes hereof, it is 
sufficient to note that the logic 38 receives an electrical signal from 
the probe elements 40 related to the amount of moisture in the soil at the 
active depth of the elements 40. In the preferred embodiment, the elements 
40 are located in a probe member 42 having depth indicia 44 on the outer 
surface thereof. The preferred probes are accompanied by an instruction 
sheet (not shown) indicating the proper depth for sensing with respect to 
various plants (and lawn products). Again, this information is well known 
to those skilled in the nurseryman's art and, per se, forms no part of the 
present information. Therefore, it is not set forth in detail herein. 
The second input to the logic 38 in the preferred embodiment comes from 
input parameter means 46. This can be in the form of any of various types 
of devices known in the art for indicating selectable choices. The source 
of the information is the instruction sheet mentioned above. By means of 
the input parameter means 46, the user informs the logic 38 what type of 
plants are being watered according to various established groups having 
common watering needs. Thus, plants needing moisture to a certain degree 
at a depth of six inches would be watered to that state. 
The output from the logic 38 is connected to an RF (radio frequency) 
transmitter 48. The transmitter 48 is connected to an antenna 36 and an 
identification number selector 50. The identification number selector 50 
employs switches by means of which the user can set the probe 24' to the 
same station identification number as the wire 16 operating the branch's 
valve 12. In operation, the controller 14' is set to come on (i.e. offer 
the opportunity for watering) more often than necessary and at the 
preferred hours for irrigation (i.e. off hours for other water uses and 
times of minimum evaporation loss). As long as the probe 24' finds that 
the local area requires additional water to achieve the conditions that 
the input parameter through means 46 dictate, the connection to the 
associated valve 12 is made and water flows to the local sprinkler heads 
20. When the conditions have been met, the logic 38 causes the transmitter 
48 to send a signal to the receiving logic 34 with the station 
identification number appended thereto. Upon receiving the signal, the 
associated switch 32 for that branch pipe 18 is opened, causing the water 
flow thereto to be stopped. To prevent undesired short term watering, the 
logic 38 includes a working band of water depth swing; that is, once the 
conditions have been met, the soil must dry out to a given upper limit 
before water will be requested again, even though the moisture has risen 
above the set depth for the conditions. As those skilled in the art will 
readily appreciate, the probes 24' require a local power source to provide 
for their operation. In the preferred embodiment, power is conserved by 
the probe 24' sending its signal only as a short pulse on a periodic basis 
when the conditions are fulfilled. The preferred power source is a 
rechargeable battery 52 which is recharged by a solar cell 54 disposed on 
the top of the probe 24. 
A variation of this approach is shown in FIG. 5. This embodiment is 
particularly useful in correcting a system that is not operating properly. 
Some local digging is required; but, as will be seen, it is minimum and 
should be of little consequence, even in an application such as a golf 
course or the like. The original (or a new prior art) controller 14 can be 
employed, if desired, to offer the opportunity for watering more often 
than necessary and at the preferred hours for irrigation as in the 
embodiment described above. Alternatively, while not preferred, a manual 
valve could be employed or the input pipe 10 simply left operably 
connected at all times. In this embodiment, each branch pipe 18 (or 
sub-branches thereof as desired or necessary) is provided with a local 
valve 56. The local valve 56 can be directly wired or be wireless and 
operate in the manner of the controller 14' described above. In either 
case, there is a probe 24' as described above which operates its 
associated valve 56 (by wire or wirelessly) to provide moisture as 
necessary to achieve its pre-set conditions. As can be appreciated, the 
only digging required to retrofit an existing irrigation to this 
embodiment is that necessary to add the valves 56 in line with the branch 
pipe 18--which is obviously minimal. 
FIG. 6 depicts a variation of the previous embodiment. This variation 
requires no digging and provides even better control of the watering of an 
area. In this case, the local valves 56' are disposed in the riser pipes 
22 of each sprinkler head 20. Such an approach would, of course, be more 
costly; but, for commercial applications and considering the cost of 
replacing lost plants expended each year throughout the country, the cost 
savings would most likely offset the additional cost of the equipment. 
Also, allowing for the reduced cost of installation over that of prior art 
systems, the cost for the additional equipment might actually be offset by 
the greatly reduced installation costs. 
A preferred arrangement for the local valve 56 and probe 24' is shown in 
FIG. 7. The valve 56 is of minimal size and is connectable in series with 
the riser pipe 22. For commercial applications where the sprinkler head 20 
is removable from the riser pipe by means of a "quick disconnect" coupling 
(such as along freeways so as to prevent theft of the sprinkler heads), 
the valve 56 can be provided with quick disconnect couplings as well. As 
mentioned with respect to another embodiment previously described herein, 
the associated probe 24' in its preferred embodiment is connected to the 
valve 56 by a connecting wire 58 and is powered by a rechargeable battery 
52 that is recharged by a solar cell 54. 
A variation of the arrangement of FIG. 7 is shown in FIG. 8. This unitary 
embodiment can be employed with underground pipe as part of a permanent 
irrigation system; but, is preferred for use with pipe or hose in an 
above-ground arrangement for either temporary or permanent use. In this 
embodiment, there is a valve body 60 having an input connection 62 on one 
side and a first output connection 64 on the top thereof. Preferably, the 
valve body 60 is made of plastic. The input connection 62 can be a slip 
fit for use with PVC, ABS, or the like, pipe or, preferably, threaded to 
connection to a standard garden hose. The first output connection 64 is 
threaded to receive a standard sprinkler head 20 therein. Preferably, 
there is a second output connection 66 connected directly to the input 
connection 62 and of the same type (i.e. slip or threaded) by means of 
which several of the valve bodies 60 can be interconnected at spaced 
intervals. Again, preference is for a threaded garden hose connection with 
a removable cap 68 provided for the case of single use (and for the last 
one in a string). The local valve 56' is contained therein and disposed 
between the input connection 62 and first output connection 64 to control 
the flow of water to the sprinkler head 20. A probe member 42 extends 
downward from the body 60 and contains probe elements 40 therein as with 
the probes previously described. There is also a battery 52 for power and 
logic 38 for operating the valve 56' as a function of the local moisture 
as determined from the signal from the probe elements 40, again as 
previously described. If desired, input parameters could also be provided 
as in previous embodiments. This embodiment is particularly useful in 
watering areas such as newly seeded areas where a constant moisture level 
must be maintained for a period of time to assure proper germination of 
the seeds. Prior art controllers 14 are simply not equipped to turn on the 
water in an area at numerous times throughout the day and night to assure 
a constantly moist environment. Thus, someone must constantly turn the 
sprinkler off and on during this period. By employing this embodiment of 
the present invention, one or more sprinkler heads can be placed in the 
newly seeded area on the end of a garden hose and will turn on and off 
automatically, as necessary, to maintain the soil in the proper state of 
moisture for seed germination. 
Finally, as shown in FIG. 11, the preferred embodiment of the local valve 
56 arrangement of FIG. 6 includes the additional capability of fertilizing 
the local area (and plants) according to a pre-established pattern as set 
to best suit the particular plants and employing the proper fertilizer 
type for the plants. Fertilizer pellets in various types for various plant 
varieties are well known and available commercially for use with hand 
watering and fertilizing devices. These pellets are concentrated and small 
in size and, therefore, are preferred for this variation of the present 
invention. Liquid, granular, or other types of concentrated fertilizers 
could, of course, be employed if desired by making appropriate 
modifications to the design. As with the embodiment of FIG. 8 described 
previously, there is a valve body 60' having an input connection 62 for 
the attachment of a water source thereto and an output connection 64 into 
which a sprinkler head 20 is threaded. A bore 63 extends between the input 
connection 62 and the output connection 64. The valve body 60' includes a 
compartment 70 which is sealably closed by a cap 72 for holding the 
concentrated fertilizer 74. A first conduit 76 connects the compartment 70 
with the output connection 64 and a second conduit 78 connects the 
compartment 70 with the input connection 62 whereby water can enter the 
compartment 70 and dissolve the fertilizer 74 to make a concentrated 
solution which can be added to the water flowing through the valve body 
60' by venturi or suction action in a manner well known to those skilled 
in the art. A valve 80 is disposed in-line with the first conduit 76 to 
control the flow of the fertilizing solution. 
The heart of the fertilizing apparatus is a mechanical timer 82 which is 
operated by the turbine wheel 84 disposed in the bore 63 in the path of 
the water flow. The timer 82 is connected to operate the valve 80. 
Additionally, there is a cam wheel 86, or the like, operated by an 
advancing shaft 88 moved by a diaphragm 90 disposed in the bore 63 which 
activates the connection of the timer 82 to the valve 80. Such apparatus 
is representative only and the functional aspects to be described can be 
accomplished by any of several approaches well known to those skilled in 
the art. Preferably, the amount of time that the timer 82 maintains the 
valve 80 in an open state during watering is adjustable within the timer 
82 as is the frequency with which the cam wheel 86 activates the timer 
connection (as by employing addable/removable cams 92 on the wheel 86 that 
move the shaft 94 that activates the timer's connection to the valve 80. 
In this way, as will be appreciated from the following description, the 
duration and frequency of the fertilizing process at each sprinkler head 
can be set to best suit the needs of the system. As those skilled in the 
art will also appreciate, while the fertilizing option of the present 
invention as now being described is preferably incorporated into the 
valves of a control system as hereinbefore described, the same novel 
approach could also be incorporated into a stand alone fertilizing unit to 
be added in-line at any point in an irrigation system's piping. 
In use, each time the particular sprinkler is activated (manually or by 
automatic operation), the diaphragm 90 is depressed by the pressure of the 
water within the bore 63 thereby causing the cam wheel 86 to be advanced 
one position. At the pre-set number of operations (e.g. every fourth 
watering), a cam 92 moves shaft 94 which causes the valve 80 to opened by 
the timer 82. The valve 80 remains open (thereby adding fertilizer to the 
water from the sprinkler) for the time pre-set into the timer 82 and then 
is closed. The watering process then continues without the addition of the 
fertilizer--which is the preferred method of fertilizing an area. 
Thus, it can be seen that the irrigation apparatus of the present invention 
has truly met its stated objectives by providing various embodiments which 
can be employed in new or retrofit applications to provide in automated 
irrigation system which maintains each defined area in a proper state of 
watering and fertilization according to pre-set conditions.