Patent Publication Number: US-2011068809-A1

Title: System and method for determining moisture content in a bale of hay

Description:
FIELD 
     Embodiments of the present invention relate generally to moisture detectors for hay balers and methods of determining the moisture content of bales of hay. 
     BACKGROUND 
     Bales of hay are commonly prepared by cutting a crop, such as alfalfa, timothy, clover, etc. near the ground and allowing it to dry. The dried hay is raked into rows and bailed using a hay baler. The bales of hay may be small square bales, large square bales or round bales. Irrespective of what type of hay bale is being produced, it is important to know the moisture content of the hay during the baling process. Too high of a moisture content and the bale will mold, or worse spontaneously combust. Too low of a moisture content may cause loss of nutritional content. 
     Electric moisture testers for use with hay balers are known. One type of moisture detector employs a sensor having two electrodes mounted in close proximity to one another in the bale chamber. When a bale of hay is in contact with the electrodes a resistance measurement through the hay is measured, and converted into a moisture content of the hay bale. This type of sensor measures resistance across a small area on one end of the bale of hay. Another type of sensor for a moisture detector is described in U.S. Pat. No. 6,377,058. This sensor has two electrodes that are star shaped wheels spaced apart from one another. The star shaped wheels have points that penetrate the hay bale and a resistance measurement is taken across a portion of the bale of hay. 
     SUMMARY 
     Systems for measuring the moisture content in a bale of hay are provided. An embodiment of the system includes a first pair of electrodes configured to mount in a first position in a bale chamber and at least one additional electrode configured to mount in a second position in the bale chamber. The system also includes a controller having circuitry to obtain a first measurement between the first pair of electrodes while the electrodes are in contact with a bale of hay, and a second measurement between at least one of the first pair of electrodes and the at least one additional electrode while the electrodes are in contact with the bale of hay. The controller includes circuitry to output a signal indicative of the moisture content of the bale of hay as a function of the first and second measurements. The controller may have a display for displaying the moisture content, and/or circuitry for communicating the signal indicative of the moisture content to a remote receiver located on a tractor for display on a monitor. 
     Methods for determining the moisture content of a bale of hay are also provided. One embodiment includes taking a first measurement between a first pair of electrodes while the electrodes are in contact with a side of a bale of hay and taking a second measurement between at least one of the first pair of electrodes and at least one additional electrode, wherein the first pair of electrodes and the at least one additional electrode are positioned so that a signal passing between them travels through at least substantially the width of the bale of hay. The method further comprises providing an output indicative of the moisture content of the bale of hay as a function of the first measurement and the second measurement. 
     In addition, a method for use of a moisture testing device for use on multiple types of hay balers is provided. An embodiment includes providing a moisture testing device, providing a data set for each type of hay baler that may be selected and having an input for selecting a type of hay baler that is to be used. In one embodiment, the method further includes taking a measurement between a first set of electrodes while the electrodes are in contact with a bale of hay and providing an output indicative of the moisture content of the bale of hay as a function of the measurement and the data set for the selected type of hay bale. 
     These and other features and a more thorough understanding of the invention may be achieved by referring to the following description, taken in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exemplary block diagram of system for determining moisture content in a hay bale; 
         FIG. 2  is an exemplary diagram of a sensor for the system for determining moisture content in a hay bale; 
         FIG. 3  is an exemplary top view of a controller for a system for determining moisture content in a hay bale; 
         FIG. 4  is an exemplary electrical block diagram of a system for determining moisture content in a hay bale; 
         FIG. 5  is an exemplary flow chart of a logic diagram in accordance with one embodiment of a method for determining the moisture content of a hay bale; 
         FIG. 5A  is an is an exemplary flow chart of a logic diagram in accordance with one embodiment of a method for determining the moisture content of a hay bale; and 
         FIG. 6  is an exemplary flow chart of a logic diagram in accordance with one embodiment of a method for using a single controller to determine the moisture content of different types of hay bales. 
     
    
    
     DETAILED DESCRIPTION 
     The following includes definitions of exemplary terms used throughout the disclosure. Both singular and plural forms of all terms fall within each meaning. Except where noted otherwise, capitalized and non-capitalized forms of all terms fall within each meaning: 
     “Circuit communication” as used herein indicates a communicative relationship between devices. Direct electrical, electromagnetic, and optical connections and indirect electrical, electromagnetic, and optical connections are examples of circuit communication. Two devices are in circuit communication if a signal from one is received by the other, regardless of whether the signal is modified by some other device. For example, two devices separated by one or more of the following—amplifiers, filters, transformers, optoisolators, digital or analog buffers, analog integrators, other electronic circuitry, fiber optic transceivers, or even satellites—are in circuit communication if a signal from one is communicated to the other, even though the signal is modified by the intermediate device(s). As another example, an electromagnetic sensor is in circuit communication with a signal if it receives electromagnetic radiation from the signal. As a final example, two devices not directly connected to each other, but both capable of interfacing with a third device, for example, a CPU, are in circuit communication. Also, as used herein, voltages and values representing digitized voltages are considered to be equivalent for the purposes of this application and thus the term “voltage” as used herein refers to either a signal, or a value in a processor representing a signal, or a value in a processor determined from a value representing a signal. 
     “Signal” as used herein includes, but is not limited to one or more electrical signals, analog or digital signals, one or more computer instructions, a bit or bit stream, or the like. 
     “Logic” is synonymous with “circuit” as used herein and includes, but is not limited to hardware, firmware, software and/or combinations of each to perform a function(s) or an action(s). For example, based on a desired application or needs, logic may include a software controlled microprocessor or microcontroller, discreet logic, such as an application specific integrated circuit (ASIC), or other programmed logic device. Logic may also be fully embodied as software. The circuits identified and described herein may have many different configurations to perform the desired functions. 
     The values identified in the detailed description are exemplary and they are determined as needed for a particular moisture detector system design. Accordingly, the inventive concepts disclosed and claimed herein are not limited to the particular values or ranges of values used to describe the embodiments disclosed herein. 
       FIG. 1  is a simplified exemplary block diagram of an embodiment of a system  100  for determining the moisture content of a bale of hay in a bale chamber  110 . The system  100  includes two sensors  120 ,  130 , a controller  140  and a remote display  160 . The first sensor  120  includes a pair of electrodes  122 ,  124  secured to a non-conductive mounting bracket  126 . Similarly, second sensor  130  includes a pair of electrodes  132 ,  134  secured to a non-conductive mounting bracket  136 . Although the embodiments described herein utilize a pair of electrodes at each sensor, the use of one pair of electrodes at one sensor  120  and one additional electrode at the other sensor  130  remote from the first sensor  120  is also contemplated and is within the scope of the inventions described herein. Bale chamber  110  may be a round bale chamber, a small square bale chamber, a large square bale chamber, or any other chamber intended for the use of hay bales. 
     Sensors  120 ,  130  are mounted in the inside of a bale chamber  110  of a hay baler (not shown), and preferably mounted on opposite walls of the bale chamber  110 . However, sensors  120 ,  130  may be mounted on the same wall or adjacent walls of the bale chamber  110 . The first sensor  120  is in circuit communication with the controller  140  through cable  152 . The second sensor  130  is in circuit communication with the controller  140  through cable  154 . Controller  140  is in circuit communication with remote display  160  through cable  166 . Optionally, one or more of the cables  152 ,  154 , or  166  may be replaced by a wireless connection (not shown). Still yet, in one embodiment, a display may be located on the controller  140  (not shown). 
     Generally in operation in one embodiment, as a bale of hay passes through the bale chamber  110 , controller  140  may take a first measurement between electrodes  122  and  124 , a second measurement between electrodes  132  and  134 , and a third measurement between electrodes  122  and  132 . The controller  140  may utilize the data from the first, second and third measurements to determine the moisture content of the bale of hay. Then the controller  140  communicates a signal indicative of the moisture content of the hay bale to a display, such as a remote display  160  through cable  166  where it is displayed to an operator. Cable  166  may be a proprietary bus, an ISO CAN bus, or other standard protocol bus. A more detailed description of the operation is provided below. 
       FIG. 2  is an embodiment of a sensor  200  for use in a system for measuring the moisture content of a hay bale. The sensor includes a non-conductive bracket  201 , which has a sloped or angled leading surface  210 , which slopes toward the surface of a bale chamber. The sloped surface  210  is positioned toward the incoming hay (not shown) so that the compacted hay rides over top of the sensor  200 . Thus, baled hay moves in the direction H shown by the arrow in  FIG. 2 . Mounting holes  212  on the leading edge of the mounting bracket  200  help prevent hay from getting between the sensor  200  and the bale chamber wall (not shown) and shearing the sensor off of the bale chamber wall. Sensor  200  includes two electrodes  202 ,  204 , which are preferably elongated to provide a larger surface area for contacting the hay. Electrodes  202 ,  204  are preferably spaced about an inch apart. In one embodiment, mounting bracket  201  is extruded from a high density plastic and has slots machined in it to receive electrodes  202 ,  204 . Electrodes  202 ,  204  are secured to the mounting bracket  201  by conventional means through mounting holes  206 ,  208 . Electrodes  202 ,  204  and mounting bracket  201  may have holes  214 ,  216  through them for receiving bolts (not shown). The bolts extend through the wall of the bale chamber and have an isolating sleeve or collar (not shown) around them to electrically isolate the bolt from the wall of the bale chamber. The bolts provide a means for making electrical connections on the outside of the bale chamber to the electrodes located on the inside of the bale chamber. 
       FIG. 3  illustrates a controller  300  in accordance with one embodiment of the present invention. Controller  300  has a housing  301  including a display  312 , an on/off button  314 , a mute button  324 , an internal calibration button  326 , and a user interface  316 . The user interface  316  includes a mode button  318  and two arrow keys  320 ,  322 . In operation, a user may turn the controller  300  on by pushing the on/off button  314 . The user may push the mode button  318  to enter a programming mode. The user presses the up key  320  and the down key  322  to scroll through options that may be changed. Those options may include offset  302 , high limit  306 , low limit  308  and baler type  310 . 
     The user may enter the programming mode by pushing mode  318 , scrolling to baler type  310 , and pushing the mode button  318  to select baler type  310 . Then the user presses the up key  320  or the down key  322  to select a baler type, for example, a small square baler, a large square baler, or a round baler. Once the correct type of hay baler is highlighted, the user pushes the mode button  318  to select the type of hay baler. 
     The high limit  306  is used to trigger an alarm if the moisture content is above a set limit. If the user wants to change the high limit  306 , the user pushes the mode key  318  and scrolls to the high limit using either the up key  320  or the down key  322 . Once the high limit  306  is highlighted, the user pushes the mode button  318  to select high limit  306  and sets the high limit  306  by using the up key  320  or down key  322  and pushing the mode button  318  when the desired limit is highlighted. The newly set high limit  306  is the maximum moisture content desired. During operation if the moisture content of the bale of hay exceeds the high limit  306 , an alarm will sound. The alarm may be muted by pushing the mute button  324 . In addition, a user may set the low limit  308  in the same way described for the high limit  306 . The low limit  308  may be used to alert the user if there is not enough moisture in the bale of hay. 
     The calibrate button  326  may be used to calibrate the controller  300 . The user simply pushes the calibrate button  326  and the controller  300  calibrates itself by applying a known load (not shown) across one of the sensor inputs. 
     Finally, the user may set the offset  302  by the procedures identified above for setting the high limit  306  and the low limit  308 . The offset  302  may be used to offset the moisture readings based on the actual deviation from a true moisture content. For example, if the controller  300  displays a moisture content of 18% on display  312  and the user tests a core sample of the bale of hay and determines that the actual moisture content is 17%, the user may use the offset  302  to subtract 1% from future moisture readings on the display  312 . 
     In another embodiment, controller  300  enters its operational mode upon start up. If a user presses the mode  318  button, controller  300  enters the programming mode and display  312  displays an arrow identifying which programming mode is active. Pressing mode  318  multiple times scrolls through the available programmable options. For example, pressing mode  318  once causes offset  302  to be identified and active so that the offset may be programmed. Pressing mode  318  a second time causes high limit  306  to be active, pressing mode  318  a third time causes low limit  308  to be active and pressing mode  318  a fourth time causes baler type  310  to be active. When a particular programming mode is active, the user may use the up key  320  or down key  322  to program a new setting. After selecting the desired setting the user simply waits a predetermined time and then controller  301  automatically saves any changes made and reverts to its operational mode. 
     Optional inputs (not shown) may include an input for selecting the width of a bale of hay that is to be produced by the hay bailer. For example, round balers may produce different widths of hay bales, such as for example, a width of 4 feet, 4.5 feet, 5 feet, 5.5 feet, etc. Selecting the width of the hay bale may be used to provide a more accurate moisture content. In addition, other inputs (not shown) may include, for example, a “density” input that allows a user to select the density of the hay bale being produced, which may be used to increase the accuracy of the moisture content output. The user may select a width or density by using the mode button  318  as described above. The widths and densities may be pre-stored values, or the user may use the up key  320  and down key  322  to manually set the values. 
       FIG. 4  illustrates a simplified block diagram of the electrical components of a system  400  for determining moisture content in a bale of hay in accordance with one embodiment of the present invention. The exemplary embodiment of system  400  includes a controller  415  that has a processor  420  in circuit communication with an input  430 , a display  435 , memory  425  and a sensor controller  418 . Sensor controller  418  includes an analog to digital converter, which is in circuit communication with a pair of sensors  402 ,  406 . There are also any of a number of switching components (not shown), such as, for example, relays or transistors, for controlling which electrodes are being used at various times to obtain measurements. First data set  440  and second data set  450  are stored in memory  425 . Additional data sets may be used for specific applications, and optionally the data sets may be stored in a single database. 
     The components illustrated in  FIG. 4  may be arranged or grouped differently depending on the design parameters. For example, the analog to digital converter of sensor controller  418  may be internal to processor  420 . Another example is memory  425  may be internal RAM, external RAM, an internal or external EEPROM, or any other type of internal or external memory. The particular configurations illustrated herein are not meant to be limiting in any way. 
     First data set  440  may be a database that correlates a digital value of a measurement (taken between a first pair of electrodes) to a moisture content of a bale of hay. First data set  440  may be developed based on, or derived from, a series of test measurements taken from a similarly situated first pair of electrodes, for example, a pair of electrodes in close proximity with one another and in contact with the same edge of a hay bale. Similarly second data set  450  may be a database that correlates a digital value (of a measurement taken between a second pair of electrodes) to a moisture content of a bale of hay. Second data set  450  may be based on, or derived from, a series of test measurements taken from a second pair of electrodes. The second pair of electrodes may, for example, contact opposite edges of a hay bale. Other electrode positions may be used and the description herein of having electrodes adjacent to one another or on opposite edges of a hay bale is not required. However, the data sets are preferable compiled using test data from similarly situated electrodes. 
     Optionally, formulas for the moisture curves may be used instead of data sets. Formulas for the moisture curve may be derived, for example, by plotting the data set and calculating, for example, a second order polynomial, a fourth order polynomial, or other similar type of equation. Accordingly, it should be understood that in the descriptions of the embodiments herein, when a “data set” is described, it may include use of a moisture curve formula. 
     In operation, to determine moisture content of a hay bale, the processor  420  initiates a request through line  417  to the sensor controller  418  to obtain a first measurement across the electrodes  403 ,  405  of the first sensor  402 . A signal, such as, for example, a 5 volt signal is transmitted to electrode  403  through cable  404 . When a hay bale (not shown) is in contact with both electrodes  403  and  405 , a portion of the signal transmitted to electrode  403  is received by electrode  405  and communicated to sensor controller  418 . The higher the moisture content the more conductive the hay bale is and the lower the voltage drop across sensor  402  through cable  406 . The signal is converted from an analog signal to a digital signal and communicated to the processor  420  through line  419 . The processor  420  compares the value of the signal to a first data set  440  stored in memory  425  and determines a first moisture content measurement of the bale of hay and stores that value in memory  425 . Optionally, the value of the signal may be applied to a first moisture curve formula to determine a moisture count. This step may be repeated any number of times and averaged to determine a first moisture content measurement. 
     Processor  420  may issue a similar request to take a measurement between electrodes  407  and  409 . A signal is transmitted through cable  408  to electrode  407  and conducted through the hay bale to electrode  409  and communicated through cable  410  back to sensor controller  418  and converted to a digital signal. The digital signal is communicated to the processor  420  and the signal is compared to the first data set  440  to determine a second moisture content measurement of the hay bale. Optionally, the value of the signal may be applied to the first moisture curve formula to determine a moisture count. Again this step may be repeated any number of time and averaged to determine a second moisture content. The second moisture content measurement is stored in memory  425 . 
     Then processor  420  may issue a request to take a measurement between electrode  403  and electrode  407 . Sensor controller  418  transmits a signal through cable  404  to electrode  403 . The signal is transmitted from electrode  403  through the hay bale to electrode  407  where the signal is transmitted back to the sensor controller  418  and converted to a digital signal and a value is communicated to the processor  420 . Processor  420  compares the value to the second data set  450  to determine a third moisture content measurement of the hay bale. Optionally, the value of the signal may be applied to a second moisture curve formula to determine a moisture count. Again this step may be repeated any number of times and averaged to determine a third moisture content. The third moisture content measurement is stored in memory  425 . 
     Processor  420  compares the first, second and third moisture content measurements and provides a final moisture content output to display  435  through line  423 . The final moisture content is a function of at least two of the first, second and third moisture content measurements, and preferably a function of all three moisture content measurements. 
     In one embodiment, the user may select a hay bale width. A dataset or moisture curve formula for each of the different widths of hay bale may be provided and used in the determination of the moisture content. Optionally, a scaling factor may be used to scale a data set or moisture curve formula instead of providing a separate data set or moisture curve formula based on a variety of widths. Similarly, in one embodiment the user may select a hay bale density. A separate data set or moisture curve may be provided and used in the determination of the moisture content based on the density. Preferably, however, a scale factor is used to scale a data set or moisture curve formula based on the density. Thus, the final moisture content may also be a function of the width of the hay bale, and/or the density of the hay bale. 
       FIG. 5  is an exemplary flow chart  500  of a logic diagram of an embodiment for determining the moisture content of a bale of hay. A measurement is made between a first pair of electrodes at block  510 . At block  520  a determination is made whether there is hay in the baler. The determination may be made based on, for example, whether the signal between the first pair of electrodes below or above a set threshold. If no hay is detected, the logic returns to block  510  and another measurement is made. If hay is detected at block  520  a determination of whether enough measurements have been taken is made at block  525 . The number of measurements may be based on, for example, a set number of measurements that are to be averaged together, or based on obtaining a set number of measurements that are within a selected deviation of one another. If enough measurements have not been taken, the logic loops to block  510 . If enough measurements have been taken, a second measurement between one of the first pair of electrodes and an additional electrode is taken at block  530 . At block  535  a determination is made of whether enough measurements have been taken for the second measurement. If not enough measurements have been taken, the logic loops back to block  530  and additional measurements are taken. If enough measurements have been taken, the moisture content of the bale of hay is calculated at block  540  as a function of the first and second measurements and is output at block  545 . 
       FIG. 5A  is another exemplary flow chart  560  of another logic diagram of an embodiment for determining the moisture content of a bale of hay. A measurement is made between a first pair of electrodes at block  565 . A second measurement between one of the first pair of electrodes and an additional electrode is taken at block  570 . Optionally, additional measurements between different electrodes may be taken. The moisture content of the bale of hay is calculated at block  575  as a function of at least the first and second measurements and is output at block  580 . 
     Many farmers have multiple types of hay balers. For example, a farmer may have a small square hay baler for harvesting hay to store in a hay loft, or to sell to individuals who own a few horses. The small square bales typically weigh between about 50 to 75 pounds. The same farmer may also have a round hay baler for harvesting hay for his herd of cattle. The round bales may weigh 1000 pounds. In accordance with one embodiment, the farmer need only install electrodes and wiring in each of his hay balers, and he can use a single controller for all of the hay balers. 
       FIG. 6  is an exemplary flow chart  600  of a logic diagram in accordance with one embodiment of a method for using a single controller to determine the moisture content of different types of hay bales. At block  610  the program mode is selected. The user scrolls to the menu for setting the baler type at  615 . At block  620  a determination is made whether a round baler is connected to the tractor. If it is, data sets for a round baler are retrieved  625  from memory for use in correlating the measurement from the sensors into a moisture content for a round bale of hay. At block  630  a determination is made whether a small square baler is connected to the tractor. If it is, data sets for a small square baler are retrieved  635  from memory for use in correlating the measurement from the sensors into a moisture content for a small square bale of hay. At block  640  a determination is made whether a large square baler is connected to the tractor. If it is, data sets for a large square baler are retrieved  645  from memory for use in correlating the measurement from the sensors into a moisture content for a large square bale of hay. Once the appropriate data sets are retrieved from memory, the logic ends at block  628 . 
     The order in which the process flows herein have been described is not critical and can be rearranged while still accomplishing the same or similar results. Indeed, the process flows described herein may be rearranged, consolidated, and/or re-organized in their implementation as warranted or desired. 
     While various inventive aspects, concepts and features of the inventions may be described and illustrated herein as embodied in combination in the exemplary embodiments, these various aspects, concepts and features may be used in many alternative embodiments, either individually or in various combinations and sub-combinations thereof. Unless expressly excluded herein all such combinations and sub-combinations are intended to be within the scope of the present inventions. Still further, while various alternative embodiments as to the various aspects, concepts and features of the inventions—such as alternative materials, structures, configurations, methods, circuits, devices and components, software, hardware, control logic, alternatives as to form, fit and function, and so on—may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether presently known or later developed. Those skilled in the art may readily adopt one or more of the inventive aspects, concepts or features into additional embodiments and uses within the scope of the present inventions even if such embodiments are not expressly disclosed herein. Additionally, even though some features, concepts or aspects of the inventions may be described herein as being a preferred arrangement or method, such description is not intended to suggest that such feature is required or necessary unless expressly so stated. Still further, exemplary or representative values and ranges may be included to assist in understanding the present disclosure; however, such values and ranges are not to be construed in a limiting sense and are intended to be critical values or ranges only if so expressly stated. Moreover, while various aspects, features and concepts may be expressly identified herein as being inventive or forming part of an invention, such identification is not intended to be exclusive, but rather there may be inventive aspects, concepts and features that are fully described herein without being expressly identified as such or as part of a specific invention. Descriptions of exemplary methods or processes are not limited to inclusion of all steps as being required in all cases, nor is the order that the steps are presented to be construed as required or necessary unless expressly so stated.