Abstract:
A system for sectional yield measurement includes a draper frame ( 106 ); a reciprocating knife ( 112 ) fixed to a forward edge of the draper frame ( 106 ); rollers ( 122, 126 ) spaced apart from one another across the width of the draper frame (106); a first endless belt ( 120, 124 ) supported on the plurality of rollers ( 122, 126 ); load sensors ( 300 ) disposed to sense a cut crop load applied to the plurality of rollers ( 122, 126 ); and an ECU ( 204 ) coupled to the load sensors to calculate a sectional yield of the row independent harvesting head ( 102 ) based at least upon signals indicative of the cut crop load.

Description:
FIELD OF THE INVENTION 
     The invention relates to assessing the crop yield of a row independent harvesting head. More particularly, it relates to assessing the sectional yield of a row independent harvesting head. 
     BACKGROUND OF THE INVENTION 
     Agricultural harvesting heads for harvesting non-row crops (i.e. row independent crops) such as wheat, oats, and other similar grass plants go back to the 19 th  century. 
     These harvesting heads typically comprise a reciprocating knife that extends across the width of the harvesting head. 
     In one arrangement, often called a “draper head” or just a “draper”, the crop material, once severed from the ground by the reciprocating knife, falls rearward onto endless belt conveyors. These conveyors, move laterally inward from both ends towards a central region of the agricultural harvesting head, whereupon the cut crop material is deposited on a central conveyor that carries the crop material rearward and into a feederhouse on the agricultural combine that supports the agricultural harvesting head. 
     In recent years, it has become increasingly important to determine with greater resolution the performance of crops in order to cultivate the soil more carefully, apply chemicals more sparingly, and increase yields. 
     In the past, the yield of a draper head was determined by measuring the quantity of clean grain leaving the cleaning shoe of the agricultural combine and carried upward into the grain tank (i.e. the storage tank). 
     Unfortunately, since this arrangement measures the crop yield as the crop (grain in this case) leaves the cleaning shoe of the combine harvester, it inherently averages the yield across the entire width of the draper head. 
     What is needed is a system for measuring the crop yield of a draper head that indicates the crop yield in several sections across the width of the draper head. 
     It is an object of this invention to provide such a system. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the invention, a system for sectional yield measurement across a width of a row independent harvesting head, comprising: a draper frame that extends laterally and generally perpendicular to a direction of travel “V”; a reciprocating knife fixed to a forward edge of the draper frame and extending substantially the entire width of the draper frame; a plurality of rollers spaced apart from one another across the width of the draper frame, wherein the plurality of rollers rotate about axes that extend generally parallel to the direction of travel “V”; a first endless belt supported on the plurality of rollers, wherein the plurality of rollers support the at least a first endless belt, and wherein the first endless belt is disposed behind the reciprocating knife to receive cut crop material severed by the reciprocating knife; load sensors disposed to sense a cut crop load applied to the plurality rollers and to generate signals indicative of the cut crop load; and an ECU coupled to the load sensors and configured to receive the signals indicative of the cut crop load and to calculate a sectional yield of the row independent harvesting head based at least upon the signals indicative of the cut crop load. 
     The ECU may be configured to determine a change in load between adjacent rollers. 
     The ECU may be configured to determine the change in load by calculating a difference between a first signal generated by a first load sensor and a second signal generated by a second load sensor. 
     At least one end of each of the plurality of rollers may be supported in a corresponding roller mount and the load sensors may be disposed to sense a load applied by the at least one end of each of the plurality rollers to the corresponding roller mount. 
     The corresponding roller mount may be fixed to a transverse frame member. 
     The first signal may indicate a cut crop load on a first roller of the plurality of rollers, and the second signal indicates a cut crop load on a second roller of the plurality rollers. 
     The first roller of the plurality of rollers and the second roller of the plurality of rollers may be disposed adjacent to each other with no rollers being disposed therebetween. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a combine harvester and row independent harvesting head (here shown as a draper head) in accordance with the present invention. 
         FIG. 2  is a plan view of the arrangement of  FIG. 1  with left and right side endless conveyor belts removed. 
         FIG. 3  is a schematic diagram of the system for sectional yield measurement of the system of  FIGS. 1-2  combined with a fragmentary front view of the endless belt conveyors, rollers, and forward roller mounts taken at section line  3 - 3  in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION 
     In the discussion herein, the term “electronic control unit” or “ECU” means one ECU, or a plurality of ECUs connected together in a network, wired and/or wireless. 
     Referring to  FIG. 1 , an agricultural harvester  100  (shown herein as a combine harvester) supports a row independent harvesting head  102  (shown herein as a draper head) on a feederhouse  104 , wherein the feederhouse  104  is fixed to a forward end of the agricultural harvester  100  and extends forward therefrom. 
     The draper head  102  comprises a frame  106  that extends laterally and perpendicular to the direction of travel “V” of the agricultural harvester  100  as it travels through the field harvesting crop. The frame  106  includes a rear transverse frame member  108  and a forward transverse frame member  110 . Each of these frame members extends substantially the entire width of the draper head  102 . 
     The draper head  102  further comprises a reciprocating knife  112  that extends laterally and perpendicular to the direction of travel “V” and is fixed to a forward edge of the frame  106 , in particular to forward transverse member  110 . The reciprocating knife  112  extends substantially the entire width of the draper head  102 . 
     The draper head  102  further comprises three endless belt conveyors, a left side endless belt conveyor  114 , a right side endless belt conveyor  116 , and a center endless belt conveyor  118 . 
     The left side endless belt conveyor  114  comprises an endless belt  120  and five rollers  122  about which the endless belt  120  circulates. At least one of these rollers  122  is driven by a motor (not shown) to cause the upper surface of the endless belt  120  to travel inwardly toward a central region of the draper head  102 . This is indicated by the arrow superimposed on the surface of the endless belt  120  in  FIG. 1 . 
     The right side endless belt conveyor  116  comprises an endless belt  124  and five rollers  126  about which the endless belt  124  circulates. At least one of the rollers  126  is driven by a motor (not shown) to cause the upper surface of the endless belt  124  to travel inwardly toward a central region of the draper head  102 . This is indicated by the arrows superimposed on the surface of the endless belt  124  in  FIG. 1 . 
     The center endless belt conveyor  118  comprises an endless belt  128  that is supported on rollers (not shown) for circulating movement in a rearward direction, i.e. in a direction opposite to the direction of travel “V”, and as indicated by the arrow superimposed on the endless belt  128  in  FIG. 1 . 
     In  FIG. 2 , the endless belts  120 ,  124  have been removed for clarity of illustration. Each of the rollers  122  and  126  are supported at their forward ends on a corresponding forward roller mount  200 . Each of the rollers  122 ,  126  are supported at their rear ends on a corresponding rear roller mount  202 . The forward roller mounts  200  are fixed to the forward transverse frame member  110 . The rear roller mounts  202  are fixed to the rear transverse frame member  108 . 
     Both the forward roller mounts  200  and the rear roller mounts  202  support the rollers  122 ,  126  to which they are coupled and permit the rollers  122 ,  126  to rotate with respect to the roller mounts  200 ,  202 . Further, each of the ten forward roller mounts  200  comprises a built-in load sensor ( FIG. 3 ) that generates a signal indicative of a vertical load placed upon each of the respective rollers  122 ,  126 . By this arrangement, the weight of harvested crop on each of the rollers can be measured. 
     In  FIG. 3 , the front end of the left side endless belt conveyor  114  and the right side endless belt conveyor  116  is shown with the ten forward roller mounts  200  mounted upon the forward transverse frame member  110 . The five rollers  122  support the endless belt  120  for recirculating movement about the rollers  122 . The five rollers  126  support the endless belt  124  for recirculating movement about the rollers  126 . 
     The load sensors  300  (shown individually as load sensors  300   a - 300   j ) integrated into the forward roller mounts  200  are coupled to an electronic control unit (ECU)  204  that is configured to receive and process signals from the load sensors. The ECU comprises a digital microprocessor and a memory circuit. The memory circuit contains digital instructions. The digital instructions are executed by the digital microprocessor. The digital instructions configure the digital microprocessor to perform all the operations described herein. 
     ECU  204  is configured to determine the crop yield in each of eight sections or zones (identified in  FIG. 3  as zones A, B, C, D, E, F, G, and H) across substantially the entire width of the draper head  102 . ECU  204  does this by determining the weight of cut crop material deposited on the endless belt  120  in the endless belt  124  in each of the eight zones. 
     Thus, rather than providing a single measure of crop yield across the entire width of the draper head  102  as in the prior art, the ECU  204  can determine the crop yield in each of eight zones. This breaks down the draper head  102  into eight separate zones of yield, and thus is an eightfold increase in crop yield resolution during harvesting. 
     For purposes of explanation, each of the ten load sensors  300  have been given individual designations. 
     The load sensor  300  on the left outermost front roller mount  200  is identified as load sensor  300   a . The next innermost load sensor  300  is load sensor  300   b . The next innermost load sensor  300  is load sensor  300   c , the next innermost load sensor  300  is load sensor  300   d , and the next innermost load sensor  300  is load sensor  300   e.    
     The load sensor  300  on the right outermost front roller mount  200  is load sensor  300   f . The next innermost load sensor  300  is load sensor  300   g . The next innermost load sensor  300  is load sensor  300   h . The next innermost load sensor  300  is load sensor  300   i , and the next innermost load sensor  300  is load sensor  300   j.    
     The ECU  204  is configured to periodically read the signals from all ten load sensors  300  and to store the signal levels of each of the ten load sensors in its random access memory (RAM)  206 . This sampling is repeated at regular intervals during harvesting, on the order of every 100 ms. 
     The load signals from the ten load sensors indicate vertical loads equal to the weight of the conveyor belt (which is constant) plus the weight of the cut crop resting upon (and being carried by) the endless belts  120 ,  124 . Crop is deposited upon the endless belts  120 ,  124  over substantially their entire width since the reciprocating knife extends over substantially the entire width of the draper head  102 . 
     The amount of crop added to each of the eight zones A-H is therefore equal to the increase in weight of the crop in that section, which is equal to the increase in the vertical load indicated by any two adjacent load sensors. The ECU  204  is configured to determine the increase in vertical load in each section by subtracting the load signal generated by any load sensor  300  with the load signal generated by its next adjacent inner load sensor  300 . 
     For example, the amount of crop added to zone A is generally proportional to the magnitude of the load signal provided by load sensor  300   b  minus the magnitude of the load signal provided by load sensor  300   a . In a similar fashion, the amount of crop added to zone B is proportional to the signal of load sensor  300   c  minus the signal of load sensor  300   b . The same pattern follows in identical fashion for every one of the eight zones A-H across the width of the draper head  102 . Further, by measuring multiple loads along the length of a single endless belt  120 ,  124 , the ECU  204  provides multiple zones and yield measurements for a single endless belt  120 ,  124 . The left side endless belt conveyor  114  with its single endless belt  120  is subdivided into four zones A-D, and the right side endless belt conveyor  116  is subdivided into four zones E-H. 
     In this manner, the ECU  204  is able to measure crop yield for eight sections (zones), including four sections on each of the two endless belts  120 ,  124 , to thereby increase eightfold the resolution of crop yield measurement in a transverse direction across the entire width of the draper head  102 . The ECU  204  is similarly able to increase fourfold the resolution of crop yield measurement in a transverse direction on each of the two endless belts  120 ,  124 . While the example herein shows a draper head divided into eight zones, any other number of zones could be provided by increasing or decreasing the number of rollers and load sensors. 
     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. For example, the crop yield measurement in the example draper head  102  is provided in eight zones. By increasing or decreasing the number of rollers, the number of individual zones can be increased or decreased. Further, the load sensors are shown as a part of the forward roller mounts. They may instead be a part of the rear roller mounts. Further, both forward roller mounts and rear roller mounts may include load sensors. The ECU  204  is shown as a single ECU for convenience of illustration. It may be configured as multiple ECUs connected over a network, either wired or wireless, in which each ECU of the multiple ECUs performs a part of the functions described herein and still fall within the scope of the claims. Further, in the embodiment illustrated and described herein the header is divided into eight sections (or zones). A similar system within the scope of the claims could be provided with more or fewer zones.