Abstract:
An apparatus and method for determining grain loss of a harvesting machine. The harvesting machine has a crop-separating region with separating members. The separating members each have separation sensors for generating a signal corresponding to the crop quantity separated. This signal is delivered to an evaluating unit for further processing. Processing includes determining a separation curve for at least some of the separating zones and converting the separation curve to a characteristic quantity. From this measured characteristic quantity, a loss is determined based on a characteristic curve deposited in the evaluating unit. By avoiding direct loss measurement on the harvesting machine, the negative crop-related effects on determining grain loss are considerably reduced.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates generally to agricultural machinery, especially self-propelled harvesting machines and, more particularly, to a method and an apparatus for measuring grain loss.  
         DESCRIPTION OF THE RELATED ART  
         [0002]    A method for measuring grain loss is disclosed in EP 0 728 409. An agricultural harvesting machine having separating members constructed as separating sieves is disclosed. Separation sensors are located on the lower section of the separating member for measuring the grain separated. An evaluating unit processes the measured data from the separation sensors to determine the separation curve. With this measured separation curve, the effectiveness of the separating members is estimated. However, this method does not determine the grain loss of the harvesting machine.  
           [0003]    U.S. Pat. No. 5,015,997 describes a method for determining grain loss of agricultural harvesting machines. The method uses conventional separation sensors mounted behind the separating members for generating measurement signals. The measurement signals are for grain loss for the entire harvesting machine or for the sensed working member. Generally, the separation sensors are either a pulse pick-up or vibration pick-up type. These types of separation sensors depend on the properties of the crop creating. For example, the measurements fluctuate considerably during one day of harvesting because of the change in moisture requiring frequent calibration of the separation sensors. Another disadvantage is that these separation sensors detect the actually separated components of the crop stream. Consequently, the crop stream may have grain not separated from the harvested crop, which will have an effect on the measurements of the separation sensors resulting in an inaccurate determination of the actual grain loss.  
         SUMMARY OF THE INVENTION  
         [0004]    It is therefore an aspect of the invention to make determinations of grain loss to a large extent independently of the crop properties, so that frequent calibration of the measuring system is not necessary with the same crop species.  
           [0005]    In another aspect of the invention, there is a method for dividing the crop separating region having at least one separating member in the separating zones to avoid direct measurement of grain loss on the harvesting machine, for measuring the efficiency of the separating zones, for converting the mean efficiency value to a characteristic quantity, and for determining grain loss curve via an evaluating unit. This method is advantageous because the negative crop-related effects on grain loss determinations are considerably reduced. In particular, the calibration frequency of the measuring system is reduced or eliminated. Further, the distribution of the grains representing the loss in the crop layer exiting the combine harvester no longer play a role, as the real losses are no longer measured explicitly, but determined indirectly by means of the characteristic quantity according to the invention.  
           [0006]    In still another aspect of the invention, there is an apparatus having a structurally simple design including at least one working member and at least one separation sensor. The separation sensors are operatively connected to an evaluating unit via a data transmission system. The separation sensors divide the crop-separating region into separating zones. The separating zones are separated from one another and a line of demarcation is effected mechanically by dividing webs, through software in the evaluating unit, or combination thereof.  
           [0007]    The above aspects are merely illustrative and should not be construed as all-inclusive. The aspects should not be construed as limiting the scope of the invention, rather the scope of the invention is detailed in the appended claims.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    Reference is now made to the drawings which illustrate the best presently known mode of carrying out the invention and wherein similar reference characters indicate the same parts throughout the views:  
         [0009]    [0009]FIG. 1 is a side view of a combine harvester;  
         [0010]    [0010]FIG. 2 is an isolated view of the threshing components, separation components and evaluation unit of the combine harvester according to FIG. 1;  
         [0011]    [0011]FIG. 2 a  is a detailed view of a threshing cylinder and separation sensors shown in FIG. 2;  
         [0012]    [0012]FIG. 3 is a functional diagram of the evaluating unit shown in FIG. 1; and  
         [0013]    [0013]FIG. 4 is a functional diagram of an alternative embodiment of the evaluating unit. 
     
    
     DETAILED DESCRIPTION  
       [0014]    [0014]FIG. 1 shows an agricultural harvesting machine  1  designed as a combine harvester  2  having a front-mounted feed rake  3  for transferring harvested crop from a front attachment  4  to a threshing mechanism  6  in a crop string  5 . The crop string  5  is transported from the through the threshing mechanism  6  between at least one rotating threshing cylinders  7 , concaves and separating grates  8 . The kernels, grains or fruits are threshed and separated from the stalks, chaff, cobs or the like during processing through the threshing cylinders  7 , concaves and separating grates  8 . The kernels, grains or fruits along with short straw and chaff are separated from the stalks, chaff, cobs and large straw into a first crop stream  9 , and delivered to a grain pan  10  located below the concaves and the separating grates  8 . The grain pan  10  has vibrating sieves for moving the first crop stream  9  into a cleaning device  11 . In the cleaning device  11 , blowers  13  generate air currents  14  to separate the short straw and chaff from the kernels, grains or fruits. While the non-grain components or short straw and chaff are blown out of the harvesting machine  1  via the air current  14 , the cleaned kernels, grains or fruits are transported out of the cleaning device  11  by feed augers  15 .  
         [0015]    A second crop stream  16  is delivered to a grain-straw separator  17  designed as a rack-type straw walker  18 . During the movement of the second crop stream  16  on the grain-straw separator  17 , a third crop stream  19  is produced as a portion of the second crop stream  16  is separated by the grain-straw separator  17 . The third crop stream  19  contains kernels, grains, fruits, short straw and chaff. The third crop stream  19  is passed into the cleaning device  11  via an inclined return pan  20  arranged below the rack-type straw walker  18 . As explained above, the kernels, grains and fruits are separated from the non-grain components in the cleaning device  11 .  
         [0016]    In a rear region of the combine harvester  2 , the chaff, straw, cob and other unusable fractions from the first, second and third crop streams  9 ,  16 ,  19 , respectively, are spewed into a discharge stream  21  from the combine harvester  2 . The discharge stream  21  has a small fraction of grain  22 , which is grain loss.  
         [0017]    The threshing mechanism  6 , the grain-straw separator  17  and the cleaning device  11  form separating members  23  for separating kernels, grains or fruits in the crop streams  9 ,  16 ,  19 , so that each of the separating members  23  may be responsible for grain losses. Consequently, the embodiment described below with the example of the threshing device  6  and the rack-type straw walker  18  can also be used in the same way on the cleaning device  11  or on only one of these separating members  23  to obtain the effects described. In an alternative embodiment, the combine harvesters  2  has an axial-separation rotor  24  instead of the rack-type straw walker  18 . In another alternative embodiment, the combine harvester  2  has threshing and separation rotors instead of the threshing mechanism  6  and the grain-straw separator  17 .  
         [0018]    To be able to precisely determine the efficiency of separation of the harvesting machine  1 , it is an advantage if a crop-separating region of the at least one working member is divided into separating zones adjoining each other and associated with each separating zone is a separation sensor for generating a signal corresponding to the crop quantity separated. The more separation sensors arranged in a separating zone, the higher the accuracy of the separation efficiency value of the respective separating zone.  
         [0019]    [0019]FIG. 2 shows the threshing device  6  and the rack-type straw walker  18 . A plurality of separation sensors  26  are associated with the concaves and the separating grates  8  in a crop-separating region  25 . In one embodiment, the separation sensors  26  are rod sensors  27 , and the rod sensors  27  extend substantially across the width of the threshing device  6 . When the first crop stream  9  passes through the threshing device  6 , the kernels, grains or fruits are separated, and the separation sensors  26  are contacted and/or sense the quantity of grain contained in the first crop stream  9 . The kernels, grains or fruits come in contact with the separation sensors  26 , and the sound generated in the process is used to determine the quantity of kernels, grains or fruits separated. The separation sensors  26  are also referred to as so-called “knock sensors.” 
         [0020]    Further, the rack-type straw walker  18  have a plurality of separation sensors  30  below a separating surface  28  in a crop-separating region  29 . In one embodiment, the separation sensors  30  are rod sensors  31 , and the rod sensors  31  extend across substantially the width of the grain-straw separator  17 . As the third crop stream  19  passes through the rack-type straw walker  18 , the kernels, grains or fruits impinge on the separation sensors  30 ,  31  resulting in sound, wherein the sound is a signal which is used to determine the quantity of separated grains.  
         [0021]    Separating zones A1-A20 are associated with each separation sensor  26 ,  30 , wherein adjacent separating zones A1-A20 in some regions do not overlap. In the embodiment shown, the separating zones A1-A8 are spatially demarcated from each other mechanically by transverse webs  32 . By contrast, the separating zones A9-A20 of the rack-type straw walker  18  do not have mechanical means for demarcation of the individual separating zones A9-A20 from each other. The demarcation of the separating zones A9-A20 from each other is predetermined by software. It is within the scope of the invention that the manner of demarcation of the separating zones A1-A20 from each other is completely free and, in departure from the embodiment shown here, can be effected exclusively mechanically or by software or in any combined form.  
         [0022]    The signals X1-X20 generated in the separation sensors  26 ,  30  and corresponding to the crop quantity separated are transmitted via a suitable data transmission system  33  to an evaluating unit  34 . For reasons of simplification, the data transmission system  33  is shown only for selected separation sensors  26 ,  30  in FIG. 2. In alternative embodiments, the data transmission system  33  is made of wires or of wireless transmission paths.  
         [0023]    If the signals of the separation sensors  26 ,  30  transmitted to the evaluating unit  34  are first converted for each separating zone to a separation efficiency value of this respective separating zone, an easy conversion of the signals generated by the separation sensors  26 ,  30  is achieved. This is achieved by averaging, wherein the separation efficiency value is determined by integration of the separation curve within the respective separating zone A1-A20 and results from the ratio between the crop quantity separated over the respective separating zone and the crop quantity to be separated which is delivered to this separating zone.  
         [0024]    Determination of a loss value corresponding to the instantaneous conditions of separation is considerably simplified if the separation efficiency values of at least some of the separating zones A1-A20 are converted in the evaluating unit  34  to a single separation efficiency value, which then forms the characteristic quantity according to the invention for determining the loss of the harvesting machine  1 .  
         [0025]    As shown in FIG. 3, the signals X1-X20 corresponding to the crop quantity separated are converted as in computing step  35  to separation curves AV1-AV20 by integrating the sensed separations X1-X20 of a separating zone A1-A20 over the length L1-L20 of the separating zone A1-A20. In a second computing step  36 , a separation efficiency value AE1-AE20 is determined, which forms a ratio value between the crop stream  19  separated in the respective separating zone A1-A20 and the crop quantity to be separated which is delivered to this separating zone A1-A20, in the practical example the grains. In a third computing step  37 , these separation efficiency values AE1-AE20 are combined in the evaluating unit  34  into a mean separation efficiency value AEm. A characteristic curve  38  is plotted between a particular loss value V on the y-axis and a particular mean separation efficiency value AEm on the x-axis in the evaluating unit  34 . In other words, the characteristic curve  38  deposited in the evaluating unit  34  represents the grain loss as a function of a mean separation efficiency value. In a mathematical step  39 , a specific loss value V of the deposited characteristic curve  38  is assigned to the calculated mean separation efficiency value AEm and made displayed on a display  40 . Thus, the calculated mean separation efficiency AEm forms the characteristic quantity Y to be determined from the individual separation efficiency values AE1-AE20, for which quantity there is deposited in the evaluating unit  34  the characteristic curve  38  which shows a specific loss value V for the characteristic quantity Y determined.  
         [0026]    In an advantageous development of the invention, the method is considerably simplified above all by the fact that the crop quantity which is not separated over the last separating zone in the direction of crop discharge and which forms the loss mass is ignored, and complete separation in this last separating zone is assumed. Hence, the method becomes completely independent of frequent sensor detection of the loss of the harvesting machine  1 . Thus, it is assumed that the quantity of grains delivered to the last separating zone A20 of the rack-type straw walker  18  is completely separated thereon, so that the grain loss mass VM ignored in this way and is equal to 0 according to block diagram  41 .  
         [0027]    It is further within the scope of the invention that associated with the separating zones A1-A20 or with some of the separating zones A1-A20 is several separation sensors  26 ,  30  whose signals Xa1-Xc1 are first converted to separation curves AV1-AV20 according to the first computing step  35  of the evaluating unit  34 . In order that the method can be employed flexibly and to improve accuracy, several characteristic curves  38  can also be deposited in the evaluating unit  34  as a function of various crop-specific parameters, wherein the crop species and moisture fraction of the crop are the most important crop-specific parameters.  
         [0028]    In an advantageous development of the invention, the characteristic curves  38  deposited in the evaluating unit  34  are variable, or further characteristic curves  38  can be added to the evaluating unit  34 . A particularly simple way of varying the characteristic curves  38  arises if the signals of the separation sensors  26 ,  30  corresponding to the crop quantity separated are converted to mean separation efficiency values in the evaluating unit as a function of different crop throughputs, wherein associated with the mean separation efficiency values are in each case loss values of a particular throughput, which then form the pair of values of the characteristic curve to be newly generated. In that way, the driver of the harvesting machine  1  can provide new characteristic curves. At its simplest, this is made possible by the driver of the harvesting machine  1  picking up crop quantities defined over a given length of time by means of the front attachment  4 . The discharge stream  21  leaving the rear region of the combine harvester  2  is in this case transported above grain loss sensors  42  known in the art. The grains  22  emerging from the discharge stream  21  generate signals KS2 corresponding to the grain mass in the grain loss sensors  42 . Also, the combine harvester  2  has a grain quantity sensor mechanism  43  which at its simplest is arranged in at least one grain elevator  44  of the combine harvester  2 , which generates a signal KS1 corresponding to the total grain quantity harvested by the combine harvester  2 . In a first computing step  45 , a loss value V is determined from these signals KS1, KS2, which corresponds to the respective grain quantities. The loss value V is then deposited as a new or further characteristic curve  38  in the evaluating unit  34  as a function of the characteristic quantities Y. In an advantageous development of the invention, these loss values can be either determined on the harvesting machine  1  itself or picked up separately by the latter and deposited in the evaluating unit  34 . Thus, it is within the scope of the invention that the loss values V can also be deposited in the evaluating unit  34  without having been determined in and by the harvesting machine  1  itself.  
         [0029]    Other aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the accompanying claims. The invention in its broader aspects is not limited to the specific steps and apparatus shown and described but departures may be made therefrom within the scope of the accompanying claims without departing from the principles of the invention and without sacrificing its chief advantages.