Abstract:
An apparatus and method are provided for monitoring subsurface soil conditions in real time and communicating data about the subsurface soil conditions to a monitor that analyzes the data to provide warnings to the system operator and to automatically initiate one or more soil treatment processes. The apparatus includes nodes with soil condition sensors and radio transceivers. The nodes are communicatively connected by a network that includes at least one transceiver. The nodes optionally include means for controlling turf treatment devices in response to commands from the computer.

Description:
[0001]     This application claims priority to U.S. Provisional Patent Application No. 60/651,768, filed Feb. 9, 2005. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to an apparatus and method that uses subsurface sensors, a radio-linked network, and a computer for wireless, real-time monitoring, historical tracking and predictive modeling of subsurface soil conditions. The present invention also provides for automatic control of soil treatment equipment in response to data obtained by the sensors.  
       BACKGROUND OF INVENTION  
       [0003]     Current turf management techniques use mainly local weather station information and soil appearance and feel to decide how to treat turf using irrigation, aeration, fumigation, fertilization, and other turf treatments. There are hand held instruments with probes that can be inserted in the soil to measure turf health but these are not practical for real time monitoring. There are also applications of buried-in-ground sensors that measure turf health but these use underground wire to provide power and communications links to the above ground user and this makes wide spread use of underground sensors impractical and expensive. The method of this patent provides a way to locate an inexpensive sensor underground in the root zone of the turf without trenching or running cable. Thus, sensors can be located throughout the turf area and the superintendent can acquire data on root zone health in real-time and this allows him to better treat the turf and to minimize treatment expense and also minimize any impacts on the environment from turf treatment.  
         [0004]     Current sensors that can be buried underground for measuring turf health include their own individual electronic systems for signal processing and in situ calibration and processing so that measurements can be relatively independent of soil type. The present invention eliminates the need for these separate electronic systems by allowing these functions alternatively to be performed by software resident in the manager&#39;s computer or in the above ground transceiver, then sending necessary calibration signals to the sensor via the communication network.  
         [0005]     Current underground turf measurement sensors create a difficulty in properly locating the probes in the soil because the required trenching disturbs the soil. This trenching also requires disturbance of a large amount of the surface during the digging, cutting and backfill. The method of this patent provides a large benefit because a core of turf and soil can be easily removed using a standard cup hole cutter, the sensor node dropped into the hole, and the core replaced using the tool. This is a process that takes minutes and is currently done thousands of times a day on golf courses.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention provides a plurality of sensors connected to a radio to create a sensor node, which is buried in the root zone of turf on a golf course or other location. Data on soil conditions (especially soil conditions related to turf health parameters) is wirelessly transmitted in real-time from the node to a transceiver that is connected by a wireless or other network to a computer. The electronics for the sensor and the radio are integrated so the node is small enough to be placed in the root zone using a hole-cutting tool that is typically used to form a cup on a golf course green. Each node has one or more sensors with probes that measure a soil conditions. Sensor probes from a single node can be located at different soil depths. The sensors can be easily calibrated in place by sending calibration signals via the wireless radio link. Each node includes a power management algorithm so that the batteries that power the node will last a long time. Each node can be buried sufficiently deep to avoid damage from turf maintenance equipment and still be able to send signals through the ground to a transceiver above the surface. Because nodes do not require cabling for communications or power supply, it is possible to position nodes rapidly anywhere in the turf without need to trench and lay cable for power and communications. More than one node can communicate with each above ground transceiver. Nodes are also capable of receiving commands and controlling a variety of devices in response to such commands. The computer collects data from each node to provide comprehensive information about the subsoil conditions. The computer includes an algorithm that identifies possible undesired turf conditions based on observed subsurface conditions and also can automatically initiate soil treatment processes in response to observed subsoil conditions, according to parameters established by the operator. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:  
         [0008]      FIG. 1  is a partial sectional perspective view of a sensor node according to the present invention;  
         [0009]      FIG. 2  is a schematic view of sensors  18 , nodes and a transceiver according to an embodiment of the present invention;  
         [0010]      FIG. 3  is a schematic view of transceivers and a computer as installed in a golf course environment, according to an embodiment of the present invention; and  
         [0011]      FIG. 4  is a schematic view of the communications interconnection of an embodiment of the invention. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0012]     Referring now to the drawings, wherein like reference numerals refer to like parts throughout, there is seen in  FIG. 1 a  sensor node  10  according to the present invention, which comprises a radio  12 , an antenna  14 , a battery  16  (or other power supply), a number of sensors  18 , and an electronic circuit board  20 , all located in a node package  22 . The node package  22  is slightly less than the diameter of a golf cup hole and less than 4 inches high. Preferably, the node package  22  consists of ABS plastic water pipe that has been sealed at each end with a standard pipe plug, but other packages  22  are also acceptable and will be known to those skilled in the art. Heavy duty waterproof wires  24  extend from the package  22  and are connected to sensors  18  that preferably include soil probes that extend radially into the soil at different depths so the probe is properly surrounded by soil and a good measurement is accomplished. The wires  24  protrude through one or more holes in the package  22 , which are sealed using an “O” ring or silicon sealant. One or more sensors  18  are connected to the protruding wires  24 , for sensing soil conditions. The connections between the sensors  18  and the wires  24  preferably are made using waterproof seals such as shrink wrap.  
         [0013]     Preferably, the node  10  is buried below the depth of plugging/aeration holes and in the region of the turf root zone ( 4 - 8 ″). The depth of the sensors  18  can be selected by the course superintendent or other user based on measurement requirements for each installation. Preferably, sensors  18  are sufficiently deep that they are not damaged by turf management activity such as plug aeration.  
         [0014]     Nodes  10  according to the present invention can be used with a wide variety of sensors  18 . Sensors  18  known to be useful for turf management include moisture sensors  18 , temperature sensors  18  and salinity sensors  18 , but the scope of this invention is not limited by those examples. According to the present invention, soil temperature can be measured by sensors  18  that include thermistors and/or thermocouples. Soil moisture can be measured by sensors  18  that include gypsum or granular matrix blocks and time domain reflectometry probes. Soil salinity can be measured using sensors  18  that include conductivity and time domain reflectometry probes. The present invention, however, is intended to encompass any type of sensor  18  used to measure subsurface soil conditions. In addition, while the invention is intended to comprise subsurface nodes, it is also possible to install one or more nodes above ground to sense ambient atmospheric conditions.  
         [0015]     The data from the sensors  18  is not processed at the node  10 , but is processed when it is received at the superintendent&#39;s computer  26  ( FIGS. 3, 4 ). In this way, sensors  18  can be made less expensively, but the raw data continues to be processed to provide useful information. The above ground transceiver  28  has temporary data storage, with ultimate storage in the computer  26 . Thus, the sensors  18  can make relative measurements of soil parameters rather than absolute measurements and the manager can analyze this data on the computer  26  to guide turf treatment activities. This reduces the demands on the sensor  18  and allows the use of inexpensive, rugged sensor  18  probes. By placing the sensor  18  functions such as signal processing, analysis, calibration and display on the computer  26 , a single computer  26  can handle many sensors  18 . Because the electronics and displays are the bulk of the traditional sensor  18  expense an implementation of, for example, 100 sensor nodes  10  using the method of this patent, reduces the expense by approximately a factor of 100.  
         [0016]     The electronics necessary to power the sensors  18  and acquire data may be integrated with the node  10  radio  12  electronics. One or more batteries  16  are located in the bottom of the package  22 . Preferably, a single circuit board  20  contains the radio  12  and the electronics to power and control the node  10 . Preferably, the circuit board  20  includes power management functionality to permit long battery  16  life, for example a minimum of two years, and also includes ability to transmit battery  16  health data to the above ground transceiver  28 .  
         [0017]     According to one embodiment of the invention, the radio  12  transmits in the unlicensed frequency band (900-928 Mhz), but the principles of the invention are equally applicable to other frequencies. The radio antenna  14  preferably is contained in the top cap of the node  10  so it does not protrude into the soil above the node  10  because that soil may routinely disturbed by plugging/aeration tools.  
         [0018]     Referring now to  FIGS. 2, 3 , data is acquired by the node  10  periodically and transmitted to an above ground transceiver  28  in real-time. In addition, each node  10  is capable of receiving signals from another node  10  and retransmitting them to another node  10  or to a transceiver  28 . Circuit board  20  preferably includes memory to temporarily store data collected by sensors  18  and includes an algorithm for selectively activating radio  12  to periodically transmit stored data. Preferably, the data transmitted by each node includes label information to identify the node  10  and sensor  18  that is the source of the data and associating time information with the data so it can be analyzed accurately.  
         [0019]     The above ground transceiver  28  uses a radio and electronics package compatible with the node  10 . The above ground transceiver  28  preferably is powered by the electricity grid, and is capable of storing data received from the nodes  10 . Alternatively, transceiver  28  can be powered by a battery, solar panel or other comparable power source. The data from the above ground transceiver  28  can be transferred to the superintendent&#39;s computer  26  in a variety of ways. One is by a wired local area network. Another is by a wireless local area network that can be peer-to-peer radio links or a hybrid mesh network. A third possibility that is practical only if there are few transceivers  28  is a periodic connection of a portable computing device to the above ground transceiver  28  to download the data onto that device which is then carried to the superintendent&#39;s computer  26  for transfer.  
         [0020]     Data received from transceivers  28  is stored in the superintendent&#39;s computer  26  memory device and managed by a standard data base management software such as SQL. The data is analyzed using custom software and displayed in tabular, graphical and “dashboard” formats. The custom software can analyze calibration data and generate calibration factors to be sent to the nodes  10 . The custom software can also be used to send commands to control devices  30  (or systems), such as irrigation, fertilization or aeration systems. According to one embodiment of the invention, the superintendent&#39;s computer  26  applies an algorithm to generate control commands automatically in response to data collected by the nodes  10 . For example, the algorithm on the superintendent&#39;s computer  26  can be programmed to automatically activate an irrigation system in the vicinity of a node  10 , if the node  10  sends data showing that soil moisture sensed by the node&#39;s sensors  18  is below a designated threshold.  
         [0021]     In addition, the software analyzes the data received from transceivers  28  to determine if certain undesirable turf conditions exist in the vicinity of one or more nodes  10  or if conditions favorable for promoting such undesirable turf conditions exist in the vicinity of one or more nodes  10 . By evaluating the subsurface soil condition data transmitted by nodes  10 , the software is programmed to identify, and alert the superintendent of, the presence of conditions favorable to the development of such turf diseases as Pythium Blight, Brown patch, Summer patch, Take All Patch, Dollar Spot, Gray Leaf Spot and Anthracnose. For example, if a node  10  senses high moisture, high temperature and high salinity at a location, it is likely that one or more of the above diseases is present or is likely to develop in the vicinity of that node  10 . Furthermore, when one of these turf diseases is identified by physical observation in the vicinity of one or more nodes  10 , but was not predicted by the software based on the soil profile, the software can be programmed to use the actual historical conditions monitored by the node(s)  10  and stored in the superintendent&#39;s computer  26  as a warning profile for future occurrences of the disease.  
         [0022]     Transceivers  28  are placed approximately 4-10 feet above ground and can communicate with nodes  10  within a radius of 200-400 feet depending on terrain. The transceivers  28  are small (˜1×3″×6″) and are placed on trees, poles, irrigation control pedestals and other places in various ways so they are inconspicuous.  
         [0023]     An embodiment of the present invention includes nodes  10  that transmit control commands rather than, or in addition to, collecting data from sensors  18 . According to this embodiment, control commands from the manager&#39;s computer  26  are communicated to the above ground transceivers  28 , which transmit the commands to one or more nodes  10 . The nodes  10  then communicate the commands to one or more control devices  30  used for turf management, for example an aeration or irrigation system. According to this embodiment, the wires  24  of the node  10  are connected to turf management equipment rather than (or in addition to) sensor  18  probes.  
         [0024]     According to the present invention, the method of installing a sensor node  10  comprises the steps of (1) digging a hole where the node  10  is to be emplaced, (2) emplacing the node  10 , (3) inserting the node&#39;s  10  sensor  18  probes into root zone, and (4) refilling the hole. Preferably, the hole for emplacement of the node  10  is dug using a cup hole cutter tool, which is commonly used on golf courses to form new holes on putting greens. The nodes  10  are sized such that a hole formed by such a tool is sufficient to contain a node  10 . Preferably, before refilling the hole, an additional step of checking communication with the node  10  is also performed.  
         [0025]     While there has been illustrated and described what is at present considered to be the preferred embodiment of the present invention, it should be understood and appreciated that modifications may be made by those skilled in the art and that the appended claims encompass all such modifications that fall within the full spirit and scope of the present invention.