Abstract:
A system for measuring plant attributes comprises a plant attribute sensor ( 103, 108, 110 ); a digital a priori plant location map ( 118 ); and an ECU ( 126 ) coupled to the plant attribute sensor ( 103, 108, 110 ) and configured to retrieve and use the a priori plant map and to anticipate a plant measurement based upon the a priori plant map and to use that anticipation to improve the accuracy of the plant measurement.

Description:
RELATED APPLICATIONS 
       [0001]    This application is related to U.S. patent application Ser. No. 14/712,449 which was filed May 13, 2015 and is assigned to the owner of the present application. This application is incorporated herein by reference for all that it teaches. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to electronic systems for measuring plant attributes during harvesting. More particularly, it relates to using electronic plant maps to create a sensor sampling window in which the plant attributes are measured. 
       BACKGROUND OF THE INVENTION 
       [0003]    Systems have been proposed to measure attributes of crop plants during harvesting. In particular, row crop harvesters, such as corn heads mounted on agricultural combines for harvesting corn use plant attribute sensors such as sensors for detecting the diameter or thickness of cornstalks, as well as sensors for measuring the impact of ears of corn when they are stripped from the stalk of the corn plant. 
         [0004]    Signals from impact sensors on row crop harvesting heads such as corn heads can be electronically processed to indicate plant attributes such as the number of ears on a corn plant, the mass of each ear, the amount of seed on the ear, and crop yields. 
         [0005]    Both impact sensors and crop thickness sensors, however, suffer from noise (i.e. spurious sensor signals) due to extraneous vibrations in the machine as well as trash from the field or from portions of other crop plants. 
         [0006]    This noise may be large enough that an electronic control unit (ECU) receiving signals from the plant attribute sensors can erroneously interpret this noise as a plant attribute. 
         [0007]    A co-pending application (U.S. patent application Ser. No. 14/712,449) addresses this problem in a system for measuring plant attributes by using a vehicle guidance sensor disposed in front of the plant attribute sensors to sense individual corn plants approaching plant attribute sensors and to establish a sensor sampling window within which signals from the plant attribute sensors are gathered for processing to determine plant attributes, and outside of which signals from the plant attribute sensors are not gathered and processed to determine plant attributes. 
         [0008]    One problem with this arrangement is that it requires a vehicle guidance sensor to establish the sensor sampling window. 
         [0009]    What is needed is a system that anticipates the presence of plants that does not require the use of vehicle guidance sensors. It is an object of this invention to provide such a system. 
       SUMMARY OF THE INVENTION 
       [0010]    In accordance with one aspect of the invention, a system for measuring plant attributes during harvesting of a row crop is provided, comprising: a plant attribute sensor ( 103 ,  108 ,  110 ); a digital a priori plant location map ( 118 ); and an ECU ( 126 ) coupled to the plant attribute sensor ( 103 ,  108 ,  110 ) and configured to retrieve and use the a priori plant location map ( 118 ) to anticipate the presence of a plant to be harvested and to use the anticipated presence of a plant to improve accuracy of a plant measurement, wherein the plant measurement is provided by the plant attribute sensor ( 103 ,  108 ,  110 ). 
         [0011]    The ECU may be configured to create a sensor sampling window ( 210 ), wherein the ECU ( 126 ) is further configured to receive data from the plant attribute sensor ( 103 ,  108 ,  110 ) during the sensor sampling window ( 210 ) and wherein the ECU ( 126 ) is further configured to reject data from the plant attribute sensor ( 103 ,  108 ,  110 ) outside of the sensor sampling window. 
         [0012]    The anticipated plant measurement may be used to adjust a value of as-received data from the plant attribute sensor ( 103 ,  108 ,  110 ). 
         [0013]    The plant attribute sensor may comprise at least one of a feeler-based plant sensor ( 103 ), a stripper plate plant sensor ( 108 ), and a plant impact sensor ( 110 ). 
         [0014]    The feeler-based plant sensor ( 103 ) may be a vehicle guidance sensor. 
         [0015]    The stripper plate plant sensor ( 108 ) may be configured to generate a signal indicative of a plant stalk thickness for a crop plant disposed between two stripper plates ( 104 ). 
         [0016]    The plant impact sensor ( 110 ) may be configured to respond to impacts of ears of corn on a stripper plate ( 104 ). 
         [0017]    The system may further comprise a second plant attribute sensor ( 103 ,  108 ,  110 ), wherein the second plant attribute sensor ( 103 ,  108 ,  110 ) is coupled to the ECU ( 126 ), and wherein the second plant attribute sensor ( 103 ,  108 ,  110 ) comprises at least another of the feeler-based plant sensor ( 103 ), the stripper plate plant sensor ( 108 ), and the plant impact sensor ( 110 ). 
         [0018]    The plant to be harvested may be planted in a row. 
         [0019]    The plant to be harvested may be a corn plant. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  illustrates a system using plant maps to improve harvest data. 
           [0021]      FIG. 2  illustrates an example of how the system of  FIG. 1  uses plant maps to filter the signals from plant attribute sensors. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Referring to  FIG. 1 , a row unit  100  for harvesting corn is disposed between two crop dividers  102 . The row unit  100  includes two stripper plates  104  that are spaced apart and define a gap  105  therebetween in which the stalks of corn plants are received as the row unit  100  and the crop dividers  102  are carried through the field on a corn head to harvest the corn plants. 
         [0023]    At a forward end of the two crop dividers  102  are vehicle guidance sensors  103 . These sensors are used to steer the corn head as it travels through the field. The vehicle guidance sensors  103  include feelers  106  that extend into the gap between the two crop dividers  102 . The feelers  106  are disposed to be deflected rearward by the stalks of corn plants. 
         [0024]    A first plant attribute sensor  108 , (here shown as a stripper plate plant sensor) is coupled to the stripper plates  104  and is configured to generate a signal that indicates the gap between the stripper plates. The gap is normally zero when a corn plant is not present, but when a corn plant is drawn backward between the stripper plates  104  by forward movement of the corn head through the field, the gap between the stripper plates  104  is equal to the thickness (diameter) of the stalk of the corn plant. 
         [0025]    A second plant attribute sensor  110 , (here shown as a plant impact sensor), is coupled to the stripper plates  104  to generate a signal indicative of the impact of an ear of corn on the stripper plates  104 . 
         [0026]    A localization circuit  112 , such as a GNSS or GPS, provides a signal indicative of a location of the row unit  100  in the field being harvested. 
         [0027]    A phytolocation circuit,  114  provides a signal indicative of a location of a plant or plants in the field being harvested. 
         [0028]    A radio communication circuit  116  is provided to permit radio communication to a remote ECU. It is configured to transmit data to and from remote locations in a distributed processing arrangement or to transmit harvest data for remote storage, or to provide data on a remote display. 
         [0029]    A first digital data storage device  118  is provided to store and retrieve data about plants, such as two-dimensional or three-dimensional locations of individual plants in the field being harvested, the expected yield of these individual plants, the mass of grain of these individual plants. In its initial configuration, the first digital data storage device  118  includes an a priori map of two-dimensional or three-dimensional locations of individual plants in the field being harvested. 
         [0030]    A second digital data storage device  120  is provided to store and receive harvest data gathered during the harvesting of the corn plants. 
         [0031]    A display device  122  is provided to display data to communicate data to a human such as an operator, site manager, an owner, or other person. The display device may be configured to display per-plant, per-row, or other aggregated plant data or machine guidance information. 
         [0032]    A user input device  124  is provided to transmit information from a human such as an operator, a site manager, an owner, or other person. 
         [0033]    The display device  122  and the user input device  124  may be local devices carried through the field as crops are harvesting on the same combine harvester that is carrying the corn head on which the row unit  100  is mounted, or they may be remote devices, for example a remote user input device and display device  125 . 
         [0034]    An electronic control unit (ECU)  126  is coupled to the vehicle guidance sensors  103 , the first plant attribute sensor  108 , the second plant attribute sensor  110 , the localization circuit  112 , the phytolocation circuit  114 , the radio communication circuit  116 , the first digital data storage device  118 , the second digital data storage device  120 , the display device  122 , and the user input device  124 . 
         [0035]    The ECU  126  comprises a microprocessor and a memory circuit storing digital instructions that control its operation. The ECU  126  may comprise a single processor that is on board the combine harvester that supports the corn head on which the row unit  110  is mounted as it travels through the field harvesting crop. Alternatively, the ECU  126  may comprise a plurality of processors that are on board the combine harvester. Alternatively, the ECU  126  may comprise a network of one or more remote processors that are in communication with one or more onboard processors. 
         [0036]      FIG. 2  illustrates the operation of the system for measuring plant attributes using a priori plant maps. In  FIG. 2 , the various stages of processing and using the plant data by the present invention are shown in example form. 
         [0037]    The example shows a segment of one row of corn plants in which 10 plants should have been spaced at regular intervals of 6 inches apart. This regular, ideal spacing of each seed is indicated by the hashmarks on line  200 . In line  200 , the distance between each plant is the same. In the example of  FIG. 2 , not all of the seeds have been planted in the preferred locations, nor has every preferred location received a seed. Row  202  shows the several cases:
       1. Ideal—the seed was planted in the ideal location   2. Delayed—the seed was slightly delayed in its planting (by accident) and is therefore not quite in its ideal location   3. Skip—no seed was planted at all (by accident).   4. Double—two seeds were planted at a location by accident instead of one seed.   5. Ideal—the seed was planted in the ideal location.   6. Ideal—the seed was planted in the ideal location.   7. Advanced—the seed was planted slightly before its ideal location (by accident).       
 
         [0045]    The row  202  indicates the actual spacing of the seeds, as planted, which in the example of  FIG. 2  is six-inch spacing between adjacent seeds. 
         [0046]    The row  206  shows the location of each corn plant as that plant has grown. This location data can be gathered by cameras or other sensors during field operations such as spraying the field or fertilizing the field after the seeds have germinated and the corn plants have grown. Alternatively, location data could be collected by a dedicated scout vehicle such as an autonomous terrestrial or aerial robot (i.e. drones). The location of the plants will be the same as the location of the seeds from which they grew. Note that in row  206 , the row of location data as-scouted, seed number  10  has failed to germinate and therefore the scout vehicle has not identified any plant corresponding to location  10 . 
         [0047]    Row  208  shows sensor sample windows  210  for each of the plants identified in the as-scouted a priori plant map. The term “sensor sample window” or “window” as used herein defines a region of time within which ECU  126  is configured to read signals from the first plant attribute sensor  108  and signals from the second plant attribute sensor  110 , to process these signals as indicative of plant attributes, and to save these plant attributes to the first digital data storage device  118 . Outside of the windows, the ECU  126  is configured to not read signals from sensors  108  and  110 . During the windows, data from sensors  103 ,  108 , and  110  will be accepted and processed. During other times, data from sensors  103 ,  108 ,  110  will be ignored. Note that weed  204  is ignored because its stem is encountered outside the sample window for either the plant at the location  5  and the plant location  6 . This illustrates one way in which noise (in this case the presence of a weed) is rejected by the system. 
         [0048]    The ECU is configured to retrieve data from the a priori plant map as the combine harvester travels through the field. The ECU is configured to compare the location of the row unit and its sensors (which is provided to the ECU by the localization circuit) with the locations of each plant the vehicle is approaching (which is provided by the a priori plant map) and to create a window based upon this comparison. Knowing the location of the plants and the location of the row unit, the ECU can begin sampling sensors  103 ,  108 ,  110  just as (or slightly before) each plant arrives at the row unit, and stop sampling sensors  103 ,  108 ,  110  just after the row unit passes over the plant location and the plant has been processed. This starting point and stopping point of sampling defines the sensor sampling window. 
         [0049]    Row  212  shows a filtered plant detection signal originating from one or more of sensors  103 ,  108 , and  110 . The filtering removes noise caused by machine vibration, plant leaves, and other extraneous sources. The filtered signal may be proportional and duration or magnitude to the diameter of the plant stalk. 
         [0050]    The ECU  126  is configured to identify a plant whenever the filtered detection signal from row  212  exceeds a magnitude threshold  214 . The ECU  126  output of this thresholding is depicted in row  216  as a series of pulses of varying width. 
         [0051]    The ECU  126  is configured to classify each of the pulses shown in row  216  according to their width. The output of this classification is shown in row  218 . In this embodiment, the ECU  126  is configured to generate a count of each ear of corn, and the numerals that comprise row  218  represent the number of ears for each of the plants identified in the a priori plant map. 
         [0052]    Finally, the ECU  126  is configured to compile the data it calculated and transmit it to the display device  122 , or alternatively the display device  125  as shown in row  220 . 
         [0053]    The invention is defined by the claims, and not by the examples described above and illustrated in the Figures. The description and figures are provided simply to illustrate one possible arrangement of the invention. Other variations of the invention are contemplated.