Method and apparatus for measuring grain loss in harvesting machines

Abstract: An apparatus is provided for measuring grain loss in a harvesting machine in substantially absolute terms. This apparatus comprises one or more first detectors (S11-S14) operable to detect one or more operating condition parameters and to produce a first electrical output signal or signals representative thereof, a plurality of second detectors (S1-S5/S1′-S3′) operable to detect grain separation at a plurality of locations within the machine and to produce second electrical output signals representative thereof, processor means (37) to which the first and second output signals are applied and operable to derive therefrom a substantially absolute indication of grain loss at a given instant, and display means (38) for displaying the grain loss indication.

Description: This invention relates to an apparatus for measuring grain loss in harvesting machines. More particularly, this apparatus may be used for measuring grain losses occurring at the discharge end of, on the one hand, the threshing and separating mechanism and/or, on the other hand, the cleaning apparatus of such harvesting machines. Lost grain is that grain which is lost by way of either being entrained in the straw which is discharged from the combine separating mechanism to the ground or by way of being discharged together with chaff and other impurities from the combine cleaning apparatus. Throughout this specification the reference to "grain" is intended to refer to that part of the crop which is threshed and separated from the discardable part of the crop material which is referred to as "straw". In the following description terms such as "forward", "rearward", "left", "right" etc... are used which are words of convenience and which are not to be construed as limiting terms. Grain loss monitors for harvesting machines are known and these attempt to monitor the amount of grain which is lost by way of being entrained with the straw, chaff and other debris and not separated therefrom. To date, most of the known grain loss monitors are unable to provide an indication, in absolute terms, of the magnitude of the actual grain loss that is occurring during the harvesting operation. These monitors provide some indication which varies more-or-less proportionally with the variations in the magnitude of the actual grain losses without however being able to establish the correlation factor between this indication and the actual losses. These known grain loss monitors rely on impact detectors to "count" a fraction of the grain which is being discharged with the straw, chaff and other debris at the back of the machine without knowing however the exact relative proportion between this fraction and the total actual losses. GB-A-2.143.714 which discloses the features of the preambles of claims 1 and 24, however illustrates one attempt of providing an "absolute" grain loss monitor in that it proposes to also use, in addition to the conventional measurement values which are indicative of the shaker losses and the sieve losses, measurement means for providing measurement values which are indicative of the distance travelled by the harvester on the one hand as well as selector means which are operable to select values which are indicative of a) the grain kind, b) the harvester working width, c) the grain mass and d) the area yield on the other hand. A computer is provided to receive all the measurement and selected values to derive grain loss values therefrom by using a fixed calculation process. However, practice has shown that this approach does not produce accurate absolute grain loss values because, not only the relationship between the monitor reading and the actual grain losses appears to be far from linear but also, and even more importantly, this relationship varies widely dependent on a.o. the type of crop and the crop condition. Furthermore, a number of problems also are encountered over and above the basic problem of not being able to provide an exact measurement of the amount of grain being lost. One of the ancillary problems is that all known detectors are unable to distinguish with any assurance between impacts occasioned by grain and those occasioned by pieces of straw having a nodule at one end thereof and which can be "seen" by a detector as a grain kernel. This problem is particularly critical in wet grain conditions. Still another problem with most known grain loss monitors is the relatively complex procedure which has to be adopted to set up the monitor in the first place. Apart from having to operate a plurality of controls according to the type of crop and the condition of the crop being harvested (the latter being likely to change anyway as one proceeds with the harvesting operation), the operator has to calibrate the monitor to some extent by way of setting the relevant controls and then physically checking the straw, chaff and other debris which is being discharged by the machine and using his practiced eye to decide whether or not the extent of grain loss is acceptable. If it is not, then the controls are reset and a further check is made. When the operator decides that the grain loss is acceptable, he then attempts to operate the machine so as to keep the grain loss monitor "reading" at the same value. If the operator does not use his practiced eye to effect this calibration of a known grain loss monitor, then grain loss can be relatively high even when the monitor might indicate otherwise. This is because, if a crop being harvested is of a type or is in a condition such that it is difficult to separate grain from the straw in which it is entrained, the detectors will detect very little grain because, if the latter is not properly separated from the straw, then it will not impact the detector in the form necessary to be "counted". Accordingly, in this harvesting situation, the grain loss monitor will indicate that the grain loss is minimal and probably zero when quite the reverse situation may pertain. It will also be appreciated that, in a crop or crop condition which results in an easier separation of grain from the straw, the grain loss monitor will indicate that there is grain loss which, whilst being true, is at a level which is usually significantly less than for the crop or crop condition having the characteristic of being difficult to separate the grain from the straw. This thus is the reason why the practiced eye of the operator is required for calibration purposes. It further also will be appreciated that, even with the calibration as described above, most grain loss monitors still do not provide a "reading" in absolute figures of the magnitude of the actual losses. Instead, this monitor "reading" only indicates whether or not the actual losses are at a generally acceptable level. In addition thereto, variations in the grain loss monitor "reading" further also may be interpreted to mean that the actual grain losses vary more-or-less accordingly, i.e. increase or decrease together with an increased, respectively decreased monitor "reading" even though there appears not necessarily to exist a linear correlation therebetween. The present invention seeks to overcome not only this problem of calibration experienced with known grain loss monitors but, more importantly, to provide an apparatus which will measure actual loss of grain. According to the present invention a harvesting machine is provided which includes a grain loss measuring apparatus associated with the threshing and separating mechanism and/or the cleaning apparatus thereof for measuring grain loss from said machine; said grain loss measuring apparatus comprising : at least one pair of detector means and processor means programmed with at least one algorithm against which the output signals of the detector means are applied for deriving therefrom a substantially absolute indication of said grain loss; and said harvesting machine being characterized in that : the detector means are provided at spaced apart locations along the length of the path of the crop material through said threshing and separating mechanism and/or said cleaning apparatus for detecting grain separation rates therein at said locations within the machine and for producing electrical output signals representative thereof; and said algorithm is expressed as a ratio of the grain separation signals generated from the detector means; said ratio providing said substantially absolute grain loss indication. Preferably three grain separation detector means are associated with at least either said threshing and separating mechanism or said cleaning apparatus. A first one of said detector means is provided either generally at or adjacent to the receiving end of the separating mechanism or generally at the midpoint (as seen in fore-and- aft direction) of the cleaning apparatus. A second one of said detector means is provided generally at or adjacent to the discharge end of either said separating mechanism or said cleaning apparatus and the third one of said detector means is provided generally midway between said first and second detector means along the length of either said separating mechanism or said cleaning apparatus. These separation detector means preferably are of the impact type. The processor means have stored therein predetermined data, preferably in the form of look-up tables, and are operable to use this data when deriving said substantially absolute indication of grain loss from the output signals of the grain separation detector means. Furthermore the processor means also may be programmed to accept the manual input of operating condition parameters and may be operable to use these parameters together with said predetermined data stored in the processor means when deriving said substantially absolute indication of grain loss from the output signals of the grain separation detector means. These operating condition parameters may include both crop parameters and/or machine parameters; said parameters being representative of at least one of the following characteristics : type of crop (i.e. wheat, barley, corn ....) condition of crop (ripe, unripe ....) crop moisture content specific weight of grain (e.g. of 1000 kernels of grain) amount of material other than grain (MOG) ground speed factors (e.g. header width, wheel diameter). However, one or more of these operating condition parameters, eventually together with still other operating condition parameters, alternatively also may be detected by further detector means. These further detector means also are operable to produce a further signal or signals representative of said operating condition parameters and to apply said signal or signals to the processor means. These processor means, in this case, also are programmed to use said further signal or signals together with said predetermined data stored within the processor means when deriving said substantially absolute indication of grain loss from the output signals of the grain separation detector means. These further detector means may be formed by one or more of the following detectors : crop moisture content detector grain flow detector material other than grain (MOG) detector ground speed detector In a preferred embodiment, the processor means are programmed with at least one algorithm against which the data derived from the grain separation detector means and the operating condition parameter or parameters inputted by the operator and/or detected with the further detector means, are applied to derive therefrom said substantially absolute grain loss indication. In case more than one algorithm is stored in the processor means, the latter further also is programmed to select the appropriate algorithm for any given circumstance on the basis of the operating condition parameter or parameters. The algorithm or algorithms may be a logistic selection of the ratio or ratios of pairs of grain separation detector output signals and one or more operating condition parameters. The processor may calculate grain loss in terms of weight per unit of time although other approaches, such as calculations in terms of percentages or weight per unit of surface, are preferred. This information is indicated on a display unit. The grain flow and material other than grain (MOG) detectors may be effected by the flow metering device disclosed in EP-A-0.208.025. In addition, the grain separation detector means preferably are of the type such as disclosed for example in EP-A-0.339.140 and EP-A-0.339.142. Preferably, the type of detector of the latter disclosure is employed because the present invention actually flows from the invention of that disclosure in as much as the latter provides a detector with a high saturation point which means that it can be located at a point in the harvesting machine where the incidence of grain is very much higher than that occurring at the end of the straw walkers, for example. Thus, the detectors may be located beneath the threshing and separating mechanism of the harvesting machine so that data can be derived in respect of grain actually separated from the rest of the crop material in said mechanism and as is part of the present invention. Preferably, means are provided for converting the grain separation detector output signals and the operating condition detector signals into pulsed signals. Counter means responsive to the convertor means are operable to count the pulses of the output signals. Multiplexer means are provided to look at the counts in the counters in rotation, for example every second, and pass the data obtained therefrom to the processor means so that the latter can derive an indication of grain loss therefrom. Each counter is preferably provided with a buffer in order that, when the counter is reset, the count therein can be dumped in the buffer to allow the counter to continue counting. According to a second aspect of the present invention there is provided a method of measuring grain loss from the threshing and separating mechanism and/or the cleaning apparatus of a harvesting machine; said method being characterized in that it comprises the steps of : detecting grain separation rates at at least two spaced apart locations along the length of the flow path of crop material through said threshing and separating mechanism and/or at at least two spaced apart locations along the length of the flow path of crop material through said cleaning apparatus; producing output signals representative of said grain separation rates at said locations within the machine; applying said grain separation output signals against at least one algorithm stored within processor means and expressed in the form of a selected ratio of said output signals and deriving a substantially absolute indication of said grain loss from said at least one algorithm. This method preferably further also comprises the following additional steps of : detecting at least one operating condition parameter of said harvesting machine; producing a further output signal representative of the or each detected operating condition parameter; and using said further output signal or signals in the processor means when deriving said substantially absolute indication of grain loss from said at least one algorithm. In a preferred embodiment of the present invention, the deriving step includes the further step of selecting, in accordance to the operating condition parameter or parameters determined from said parameter detecting step, one algorithm from a plurality of algorithms stored in the processor means for utilization in determining said substantially absolute grain loss indication. A method and an apparatus for measuring grain loss in a combine harvester will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a diagrammatic side view of the combine harvester. Figure 2 is an enlarged partial view of Figure 1 showing the position of grain detector means. Figures 3 and 4 are views similar to Figure 2 but illustrating different threshing and separating means equipped with grain detector means according to the invention. Figure 5 is a graph illustrating the grain separation distribution along the length of the path of the crop material through the threshing and separating mechanism on the one hand and the grain loss on the other hand. Figure 6 is blocked circuit diagram of the overall apparatus; and Figures 7 and 8 are graphs illustrating the correlation between the grain loss readings of a known grain loss monitor, respectively the grain loss monitor according to the present invention and the actual grain losses. Aspects of the grain loss measuring apparatus according to the present invention also are disclosed in EP-A-0.339.140. The detectors utilized in the present invention preferably are of the type disclosed in more details in EP-A-0.399.142. Both of these disclosures are incorporated herein by reference. Referring first to Figure 1, the combine harvester comprises a main frame 1 having a front pair of ground engaging wheels 2 and a pair of smaller steerable rear wheels 3. The machine is provided with a header 4 comprising a reel 5, a cutterbar 6 and an auger 7 which consolidates cut crop material centrally of the machine and passes it to a crop elevator 8 which delivers it in a layer to a threshing and separating mechanism indicated generally at 9 and which may be of the type as disclosed in more details in GB-A-2.063.039 which therefore is included herein by reference. This threshing and separating mechanism 9 is shown on a larger scale in Figure 2. The rotatable threshing mechanism, which is the forward part thereof, comprises a rotatable threshing cylinder 18, which is cooperable with a stationary threshing concave 19 to thresh the crop material and to separate most of the grain from the rest of the crop material. Rearwardly of the threshing mechanism 18, 19, a rotatable straw beater 21 and stationary beater grate 22 are provided which cooperate to transfer the layer of crop material issuing from the threshing mechanism 18, 19 to the separating mechanism disposed rearwardly thereof while separating further grain through the grate 22 from the discardable part of the crop material. The separating mechanism comprises two transversely disposed rotors 23 and 24 which are cooperable with respective separator concaves 25 and 26. The forward separator rotor 23 and associated concave 25 have a width which corresponds to the width of the threshing mechanism 18, 19 and the straw beater 21 and are disposed to pass the layer of crop material in a rearward direction across the separator concave 25 while separating further grain through said concave 25. The rearward separator rotor 24 and associated concaves 26 have a larger width than the forward separator rotor 23 and have transversely opposite end portions which extend transversely beyond the corresponding opposite ends of the forward rotor 23. The rearward rotor 24 and associated concaves 26 are disposed to divide the layer received from the forward rotor 23 in two halves and to convey these halves spirally around the rearward rotor 24 in transversely opposite paths towards the discharge outlets at the respective opposite ends of the housing comprising the rotor 24 for discharge therethrough to the ground. During this spiral movement, the crop material again is subjected to a grain separating action resulting in still further grain being separated through he concaves 26. Grain separated through the threshing concave 19, the beater grate 22, the separator concave 25 and the central sections of the separator concaves 26 is received directly onto the cleaning apparatus 12. Grain separated through the transversely opposite end portions of the separator concaves 26 falls to auger troughs 11 comprising transverse augers 10 for conveying this grain to the cleaning apparatus 12. Threshed and separated grain is cleaned in a conventional manner in the cleaning apparatus 12 which comprises upper and lower sieves 61, 62 and a cleaning fan 63. Cleaned grain is received in a grain auger 13 and transferred therefrom to a grain tank 14. Tailings are received in a tailings auger 15 and taken therefrom for re-processing first by a tailings rethresher means and next by the cleaning apparatus 12. Straw issuing from the threshing and separating mechanism 9 and chaff and other debris issuing from the cleaning apparatus 12 are discharged to the ground through a straw hood 16. Grain that is discharged together with this straw, chaff and other debris forms the grain loss. The apparatus according to the present invention aims at providing an indication, in absolute figures, of the magnitude of this grain loss. The rotary threshing and separating mechanism 9 briefly described hereabove is one of various types of threshing and separating mechanisms known in the art. The more conventional threshing and separating mechanism comprises straw walker type separator means which may be substituted for the separator rotor 24 and associated separator concaves 26 according to Figures 1 and 2. This so-called conventional threshing and separating mechanism is illustrated in Figure 3. In still another arrangement shown in Figure 4, the entire threshing and separating mechanism is of a different type and comprises one or two so- called axial flow threshing and separating rotors 57 cooperable with associated threshing and separating concaves 58. A twin rotor axial flow combine of this type is disclosed in many details in GB-A-1.399.601 which equally is included herein by reference. Still other, less commonly used threshing and separating mechanisms also are known in the art. The present invention is applicable on anyone of these combine harvesters and may be used for monitoring the grain losses occurring at the discharge end of either the separating mechanism, or the cleaning apparatus or of both said separating mechanism and said cleaning apparatus. Grain loss sensors conventionally have been provided rearwardly of the discharge end of the separating mechanism and/or the upper cleaning sieve for a fraction of the lost grain kernels to impact thereon as they are discharged to the ground and so as to thereby provide an indication of the magnitude of the actual grain loss that is occurring. Occasionally such grain loss sensors also have been installed, as has been shown in EP-0.117.587, forwardly of and adjacent to the discharge end of e.g. the separator mechanism. Practice has shown, as has been explained in the introduction of this description, that these prior art arrangements give only a very inaccurate indication of the magnitude of the actual grain losses and that, by no means, this indication can be used to generate an indication of the grain losses in absolute figures (e.g. kg/ha). It has been found, in connection with the present invention, that a better indication of the actual grain losses can be derived from a plurality of measurements of the grain separation at different locations along the length of the threshing and separating mechanism, respectively the cleaning apparatus in as much as these measurements of grain separation permit a "prediction" of the actual losses that occur rearwardly of the discharge end thereof. It thus should be remarked that the arrangement according to the present invention basically measures grain separated in the separating mechanism and/or the cleaning apparatus and derives an indication for the actual grain losses therefrom, while that prior art arrangements always have attempted to directly measure a fraction of the actual grain losses. While in the following description, reference will be made mainly only to the threshing and separating mechanism and to the losses occurring at the discharge end thereof, it should be understood that the same also applies to the cleaning apparatus. Considering the grain separation rate along the length of the path of the crop material through the threshing and separating mechanism, it has been noticed that this separation rate decreases from front to rear. It further also has been noticed that, when the separation rate proximate to the discharge end is higher, the total actual losses rearwardly of this discharge end also are higher. Figure 5 schematically illustrates these findings in a graph wherein the length of the crop path through the threshing and separating mechanism is indicated on the x-axis and the separation rate is indicated on the y-axis. The discharge end of the threshing and separating mechanism is indicated on the x-axis at A and the surface X beneath the extrapolation of the separation rate curve C beyond the discharge end A is indicative of the actual grain loss occurring in a particular situation. As indicated in this Figure 5 the separation rate curve C may vary dependent on various conditions. Many influences define the precise location and shape of this curve C. However, when in any particular case, a given number of points along the length of the curve C, say e.g. three points, are determined (by measurement of the grain separation) then the shape and position of this curve C is pretty well defined and, as a consequence, the actual losses that occur at the discharge end of the threshing and separating mechanism, in principle, also can be derived rather accurately therefrom. In accordance with the present invention, a plurality of grain detector means in the form of impact detectors are provided along the length of the path of the crop material through the threshing and separating mechanism. In a preferred embodiment sensors are provided only at three locations. However, it also should be appreciated that more sensors may be provided to further improve the accuracy of the indication. On the other hand, in certain circumstances, the skilled in the art, will find that only two sensors equally will provide satisfactory results. The sensors preferably are provided only along the length of the separating portion of the threshing and separating mechanism on the one hand and/or along the length of the rear half of the cleaning sieves on the other hand. One of said sensors further also preferably is provided at the same location as where the prior art grain loss sensor members were provided i.e. either immediately behind or immediately in front of the discharge end of the separating mechanism, respectively the cleaning apparatus. With reference to Figures 1 to 4 the sensors associated with the threshing and separating mechanism are indicated at S1, S2 and S3. With reference to Figure 1, the sensor associated with the cleaning apparatus are indicated at S1', S2' and S3'. As already indicated and as the characteristics of the apparatus according to the invention are substantially the same irrespective of whether this apparatus is provided to monitor either the separator grain losses or the cleaning grain losses, only the operation thereof in combination with the threshing and separating mechanism will be described hereafter. With particular reference now to Figure 2, the detector S1 is located underneath and generally at the mid-point of the separator concave 25 (or seen in the direction of flow of crop material across the concave). The detector S2 is provided adjacent to one of the separator concaves 26 at a point generally midway (again as seen in the direction of flow of the crop material) between the inlet and the outlets of the rotor housing comprising said concaves 26 and the sensor S3 is provided adjacent to one of the offset concaves 26 and proximate to one of the discharge outlets of the rotor housing comprising said concaves 26. The sensor S3 thus is provided generally at the same location as where the prior art grain loss sensor according EP-A-0.117.587 has been provided. In Figure 2, additional optional sensors S4 and S5 also have been shown; sensor S4 being located generally adjacent the receiving edge of the separator concave 25 and the sensor S5 being provided generally at the transition between the concaves 25 and 26. As seen in the direction of flow of the crop material through the separating mechanism, the sensors are provided in the following sequence : S4, S1, S5, S2 and S3. Whenever possible, the sensors S1-S5 preferably are mounted at a specific angle to the tangent to the rotors 23 and 24 with which they are associated; this angle being in the range of 30 to 35 in order to avoid impacts upon the sensor surfaces at right angles by grain and straw which issues straight radially out of the concaves. Apart from this orientation of the sensor surfaces relative to the tangent as described, it is also necessary to position the sensors at an angle of at least 35 relative to the horizontal so as to avoid accumulation of material on top of the impact surfaces thereof. Referring now to Figure 3, it will be seen that the sensors S1, S2 and S3 are provided respectively underneath the separator concave 25 generally at a mid-point thereof; within a straw walker 55 again generally at a mid-point thereof and finally generally at the rearward discharge end of said straw walker 55. With reference to Figure 4 illustrating the axial flow type threshing and separating mechanism, the sensors S1, S2 and S3 are provided respectively underneath the middle section of the threshing and separating concave 58 and the forward and rearward edges of the concave 59 associated with the discharge beater 60. Referring now to Figure 6 of the drawings, the apparatus for measuring grain loss in accordance with the present invention will now be described. The sensors or detectors S1, S2 and S3 are, as already mentioned, of the impact type and produce an analogue signal representative of each impact detected. The sensors S1, S2 and S3 are illustrated in Figure 6, together with the further sensors S4 and S5 and associated circuitry, which are representative of any additional sensors which may be employed at any desired location in the combine harvester and which equally are of the impact type. Each sensor S1-S5 has associated with it a pulse former 32 which converts the analogue signals into calibrated pulsed signals; these pulsed signals being applied to counters 33 which have associated therewith buffers 34 into which the counts from the counters are dumped when the latter are reset, thus allowing the counters to continue counting. The output of each buffer 34 is applied to a multiplexer 35 which has a two-way connection with a microprocessor 37 to which also are connected a memory 36, a display unit 38 and a key pad 50. The memory 36 may be programmed with desired look-up tables and algorithms for calculating grain loss from the input data. The memory 36 also accepts input from the key pad 50 which is controlled by the machine operator to feed in e.g. type and condition of the crop material, different ground speed factors (e.g. cutterbar width and wheel diameter). The memory 36 further also accepts the counts from the counters 33 for storage in rotating registers in a manner to enable the microprocessor 37 to take into account the fact that it takes some time for crop material to be processed in the separating mechanism and to sequentially move past the locations of the various sensors S1-S5 from the inlet to the outlet of the separating mechanism. In other words, the microprocessor 37 does not compare the signals generated by all sensors S1-S5 at any given moment in time but instead compares related signals generated by the sensors S1-S5 at staggered time intervals. The system thus comprises time delays which are operable to synchronise the outputs of the sensors S1-S5 positioned at different locations in the process. The system further also comprises filter means for cancelling out or greatly reducing the influences of any short time, abrupt fluctuations in the magnitude of the signals. In addition to the sensors S1-S5 for detecting separated grain, the grain loss measurement apparatus also comprises a plurality of further sensors S11-S14, which are so disposed as to produce signals representative of, respectively, the moisture content of the crop being harvested; the grain flow in the combine harvester (i.e. the flow rate of the total amount of grain being harvested); the flow rate of all material other than grain MOG (i.e. mainly straw) in the combine harvester and the ground speed. The moisture content sensor S11 e.g. may be in the form of a suitable humidity sensor that may be mounted within the straw elevator housing 8. The sensing of the grain flow may be effected by way of the flow metering device disclosed in EP-A-0.208.025 and which may be associated with the clean grain elevator 27. A similar flow metering device may be provided within the straw hood 16 for sensing the MOG flow. Alternatively an indication of the MOG flow may be obtained by means of a torque sensor that may be provided within the drive line to e.g. the header auger 7. The ground speed sensor S14 may be associated with e.g. one of the steerable rear wheels 3 and may be in the form of an rpm counter. The output of each additional sensor S11-S14 is applied to an associated pulse former 43, a corresponding counter 44 and a corresponding buffer 45 before being applied to the multiplexer 35 in the same way as is done with the output signals from the sensors S1-S5. Before turning to the description of the operation, it may be useful to also consider the following : In the graph of Figure 7 the relationship between actual losses (y-axis) and the indication of these losses obtained with a conventional grain loss monitor (x-axis) is illustrated. The various curves are indicative for different crops and crop conditions. It thus will be noticed therefrom that the relationship between the monitor reading and the actual grain losses appears to be far from linear. Moreover, it also will be noticed that this relationship varies widely dependent on a.o. the type of crop and the crop condition. As a consequence it is impossible for a combine operator to derive from a given grain loss reading the actual grain loss level because, amongst other things, he does not know which one of the many curves is applicable in the condition he is operating under. Furthermore, any given variation in the grain loss reading corresponds to a larger or smaller variation in the actual losses dependent on the location along any given curve. This even further complicates intelligent utilization of known grain loss monitors. Consequently, it is highly desirable to obtain a grain loss reading of some type which has a linear relation with the actual grain loss on the one hand and of which the spreading of the linear relation, dependent on the crop and crop condition, is kept to a minimum on the other hand. (It would be ideal if this spreading could be eliminated altogether). These requirements are illustrated in Figure 8 and may be obtained by the present invention as will be described hereafter in more details. It has been found that, when using a particular algorithm of the readings obtained from e.g. the sensors S1, S2 and S3, a linear relation indeed exists between this algorithm and the actual grain losses in weight per unit of time (e.g. gram/second). Such an algorithm may be e.g. : However, other algorithms also may be used in other circumstances. Such other algorithms may be e.g. : These algorithms of the grain sensor readings thus are characteristic values calculated from readings which are indicative of the grain separation in the separation process. These algorithms, which are in the form of ratios of impact detector signals, neutralize certain factors that may have an influence on the sensor output signals such as e.g. specific weight of the grain. However, an indication of the grain losses in weight per unit of time still is not very useful either. The more useful and meaningful indications of the actual grain losses should be expressed in terms of either a percentage (i.e. of the total amount of grain harvested) or weight per unit of surface (e.g. kg/ha). Starting from the indication in weight per unit of time, an indication of the actual grain loss in terms of percentage is obtained by dividing the aforementioned algorithm of the grain separation sensor readings by the grain flow readings obtained from the grain flow sensor S12. If the results of the algorithm of the grain separation sensor readings is indicated by A, then the new algorithm giving a percentage indication is expressed by: The indication of the actual grain losses in terms of weight per unit of surface is obtained by dividing the algorithm of the grain separation sensor reading by speed readings expressed in e.g. hectare per hour. These speed readings themselves are derived from the rpm readings from sensor S14 in combination with e.g. the header width and the wheel diameter. The latter two values normally need to be fed into the microprocessor by the combine operator. In simplified form, the new algorithm giving the indication of the actual losses in weight per unit of surface is expressed by : In an attempt to reduce (or indeed ideally eliminate) the spreading of the relation between the actual grain losses and the algorithms B and C resulting from variations in the crops and crop conditions, correction factors are applied against said algorithms B and C. A first correction factor F1 takes into account crop parameters such as the type of crop (e.g. wheat, corn, barley ....) and specific weight of e.g. 1000 kernels of grain). This first correction factor F1 may be derived from the look-up tables in the memory 36 in response to the input provided by the operator. The variations in crop parameters also may dictate a different algorithm A against which the grain sensor readings S1-S5 should be applied. This again is derived from look-up tables in the memory 36. A further correction factor F2 takes into account crop condition parameters such as moisture content and MOG (material other than grain). These crop condition parameters are sensed with the sensors S11 and S13, the readings of which are applied against look-up tables in the memory 36 for determining the appropriate correction factor F2. This further correction factor F2 eventually also may take into account the degree of ripeness of the crop, this parameter normally being inputted to the processor means 37 by the operator. Again the variations in crop condition parameters also may dictate a different algorithm A against which the grain sensor readings S1-S5 should be applied. Similarly as indicated before, this may be derived from look-up tables in the memory 36 against which the readings of the sensors S11 and S13 are applied. In summary, the corrected algorithms B' and C' thus can be expressed by : B' = F1 X F2 X B C' = F1 X F2 X C In applying the foregoing principles in practice with the apparatus and the arrangement according to the present invention, the operator first has to input e.g. the wheel diameter (provided this has not yet been done by the manufacturer or the dealer), the header width and the type of crop to be harvested. During the subsequent operation of the grain loss measuring apparatus, the multiplexer 35 looks at the counts of the counters 34 and 45 in rotation. Each counter is accessed e.g. every second and the data obtained is passed to the microprocessor 37. Based on the type of crop material being harvested on the one hand and the moisture content and the amount of MOG (material other than grain) measured by the sensors S11 and S13 on the other hand, the microprocessor 37 determines practically continuously, through access to the look-up tables of the memory 36, which algorithm A ought to be used for processing the grain sensor readings S1-S5. The microprocessor 37 further also continuously calculates the algorithm A using therefore the sensor readings S1-S5. These calculated characteristic values of grain separation in the combine harvester process are corrected with the correction factors F1 and F2 which again may be derived from look-up tables in the memory 36 as already explained and against which crop parameters (such as type of crop and specific weight of 1000 kernels of grain inputted by the operator) on the one hand and crop condition parameters (such as moisture content and MOG) sensed by the sensors S11 and S13 on the other hand may be applied. To arrive at the indication of the actual grain losses in terms of either percentages of the total yield or weight per unit of surface, the corrected algorithms, as obtained in the way as indicated above, are divided in the microprocessor 37 either by the grain flow readings obtained from the sensor S12 or by measures representative of the harvesting speed or capacity in e.g. hectares per hour and which themselves are derived from the rpm readings from the rpm sensor S14 in combination with the header width and wheel diameter values previously stored in the memory 36 by the operator. The foregoing process thus provides on-the-go indications, in absolute figures, of the grain loss rates of the threshing and separating process (and/or of the cleaning process) in a combine harvester in terms of percentages of total yield and/or weight per unit of surface; these indications being displayed on the display unit 38. The present invention represents an extremely significant advance in the art of crop harvesting from the standpoint of being able to measure in substantially absolute terms the amount of crop (grain) being lost and thus being able to alter the operating conditions of the machine to maintain that loss at an acceptable level while optimizing the harvesting speed. To date, no apparatus for providing such a measurement of grain loss has been produced. While the preferred structure, in which the principles of the present invention have been incorporated, is described above and is shown in the accompanying drawings, it is to be understood that the invention is not to be limited to the particular details as described above and shown in said drawings, but that, in fact, widely different means may be employed in the practice of the broader aspects of the invention. As an example, it is conceivable that acceptable results already can be obtained with an apparatus generally as described above but wherein the moisture content sensor S11 and the MOG sensor S13 are left out. In this case, the operator eventually may have to key in some more parameters prior to starting operation. The microprocessor thus may be programmed to enable the input of specific average moisture content values on the one hand and average MOG values on the other hand. In case in addition to the foregoing also the grain flow sensor S12 and the speed sensor S14 would be left out, then the apparatus still could measure the absolute grain losses in terms of weight per unit of time (e.g. gram/sec). As already indicated, such an indication is less meaningful than the indications obtained with the preferred embodiment of the present invention. Nevertheless, the foregoing already forms a remarkable progress with respect to the state of the art. It thus is conceivable that in its simplest form, the grain loss monitor according to the invention comprises a microprocessor to which at least a pair of grain impact sensors are coupled which are operatively associated with the threshing and separating mechanism (respectively the cleaning apparatus) at different locations along the path of the crop material through the machine and which are operable to produce signals representative of the grain separation rates in said mechanism; said microprocessor having stored therein predetermined data and being programmed to enable the input of certain operating condition parameters and to compare with said predetermined data and said operating condition parameters the signals received from the grain impact sensors to derive therefrom a grain loss indication in substantially absolute figures. The type and condition of the crop material eventually together with other aspects may determine said operating condition parameters. If the foregoing apparatus further also comprises a speed sensor S14 and/or a grain flow sensor S12 then the grain loss indications can be expressed in terms of weight per unit of surface or percentage of total yield respectively. It further also will be appreciated that the display means 38 may appear in different forms such as e.g. a needle which is movable relative to a scale or an LCD.

Claims: A harvesting machine including a grain loss measuring apparatus associated with the threshing and separating mechanism (9) and/or the cleaning apparatus (12) thereof for measuring grain loss from said machine; said grain loss measuring apparatus comprising : at least one pair of detector means (S1-S5/S1'-S3') and processor means (37) programmed with at least one algorithm (A) against which the output signals of the detector means (S1-S5/S1'-S3') are applied for deriving therefrom a substantially absolute indication of said grain loss; and said harvesting machine being characterized in that : the detector means (S1-S5/S1'-S3') are provided at spaced apart locations along the length of the path of the crop material through said threshing and separating mechanism (9) and/or said cleaning apparatus (12) for detecting grain separation rates therein at said locations within the machine and for producing electrical output signals representative thereof; and said algorithm (A) is expressed as a ratio of the grain separation signals generated from the detector means (S1-S5/S1'-S3'); said ratio providing said substantially absolute grain loss indication. A harvesting machine according to claim 1, characterized in that one detector means (S1,S2,S4,S5/S1'-S2') of said pair of detector means (S1-S5/S1'-S3') is associated with a portion of either said threshing and separating mechanism (9) or said cleaning apparatus (12) at a substantial distance forwardly of the discharge end thereof and the other detector means (S3/S3') of said pair of detector means (S1-S5/S1'-S3') is provided generally at said discharge end. A harvesting machine according to claim 1 or 2, characterized in that at least three grain separation detector means (S1-S3/S1'-S3') are associated with either the threshing and separating mechanism (9) or the cleaning apparatus (12); a first one of said detector means (S1/S1') being provided either generally at or adjacent to the receiving end of the separating portion (23-26/55/58-60) of said threshing and separating mechanism (9) or generally at the midpoint (as seen in fore-and-aft direction) of the cleaning apparatus (12); a second one of said detector means (S3/S3') being provided generally at or adjacent to the discharge end of either said separating portion (23-26/55/58-60) or said cleaning apparatus (12) and the third one of said detector means (S2/S2') being provided generally midway between said first and second detector means (S1,S1'/S3,S3') along the length of either said separating portion (23-26/55/58-60) or said cleaning apparatus (12). A harvesting machine according to any of the preceding claims, characterized in that the detector means (S1-S5/S1'-S3') are of the impact type. A harvesting machine according to any of the preceding claims, characterized in that the processor means (37) have stored therein predetermined data and are operable to use this data when deriving said substantially absolute indication of grain loss from the output signals of the grain separation detector means (S1-S5/S1'-S3'). A harvesting machine according to claim 5, characterized in that the predetermined data is stored in the processor means (37) in look-up tables. A harvesting machine according to claim 5 or 6, characterized in that means (50) are provided for manual inputting to the processor means (37), and the processor means (37) are programmed to accept the manual input of operating condition parameters and to use these parameters together with said predetermined data stored in the processor means (37) when deriving said substantially absolute indication of grain loss from the output signals of the grain separation detector means (S1-S5/S1'-S3'). A harvesting machine according to claim 7, characterized in that the operating condition parameters include crop parameters and/or machine parameters; said parameters being representative of at least one of the following characteristics : type of crop (i.e. wheat, barley, corn ....) condition of crop (ripe, unripe ....) specific weight of grain (e.g. of 1000 kernels of grain) ground speed factors (e.g. header width; wheel diameter). A harvesting machine according to claim 8, characterized in that the operating condition parameters that can be inputted manually to the processor means (37) further also include a crop moisture content parameter and/or a material-other-than-grain (MOG) parameter. A harvesting machine according to any of the claims 5 to 8, characterized in that it also comprises one or more further detector means (S11-S14) coupled to the processor means (37) and operable to detect one or more operating condition parameters, to produce a further signal or signals representative thereof and to apply said further signal or signals to the processor means (37); said processor means (37) being programmed to use said further signal or signals together with said predetermined data stored within the processor means (37) when deriving said substantially absolute indication of grain loss from the output signals of the grain separation detector means (S1-S5/S1'-S3'). A harvesting machine according to claim 10, characterized in that the one or more further detector means are formed by one or more of the following detectors : crop moisture content detector (S11) grain flow detector (S12) material-other-than-grain detector (MOG : S13) ground speed detector (S14). A harvesting machine according to any of the claims 7 to 11, characterized in that the processor means (37) are programmed, on the one hand, with a plurality of algorithms (A) and, on the other hand, to select, on the basis of the operating condition parameter or parameters applied thereto, the appropriate algorithm (A) against which at least the data derived from the grain separation detector means (S1-S5/S1'-S3') is applied to derive therefrom said substantially absolute grain loss indication. A harvesting machine according to claim 3 or any of the claims 4 to 12 when appended to claim 3, characterized in that the or each algorithm (A) takes the form of any one of the following formulae wherein the symbols S1, S2 and S3 stand for the output signals derived from the grain separation detector means (S1-S3/S1'-S3') : A harvesting machine according to either claim 1 or 2 or any of the claims 4 to 12 when appended to claim 1 or 2, characterized in that the or each algorithm (A) takes the form of any one of the following formulae wherein the symbols S1 and S2 stand for the output signals derived from the grain separation detector means (S1-S2/S1'-S2') : A harvesting machine according to any of the preceding claims, characterized in that the substantially absolute grain loss indication is expressed in terms of weight per unit of time (gr/sec). A harvesting machine according to any of the claims 12 to 14 when appended to claim 11 and including a grain flow detector (S12); said apparatus being characterized in that the processor means (37) are programmed to divide the signals derived from said algorithm or algorithms (A) by the signals derived from the grain flow detector (S12) whereby the substantially absolute grain loss indication is expressed in terms of percentage. A harvesting machine according to any of the claims 12 to 14 when appended to claims 11 and 8 and including a ground speed detector (S14); said apparatus being characterized in that the processor means (37) are programmed to divide the signals derived from said algorithm or algorithms (A) by harvesting speed signals expressed in surface per unit of time (e.g. hectare/hour) whereby the substantially absolute grain loss indication is expressed in terms of weight per unit of surface (e.g. kg/ha); said harvesting speed signals themselves being derived from the ground speed detector signals (S14; e.g. rpm) in combination with the ground speed factors (e.g. header width; wheel diameter) inputted to the processor means (37) by the operator. A harvesting machine according to any of the claims 12 to 17 when appended to claim 6 and any of the claims 7 to 11, characterized in that the processor means are programmed : to apply one or more operating condition parameters against the look-up tables stored in the processor means (37) to derive therefrom a correction factor (F1, F2); and to multiply the algorithm or algorithms with said correction parameter (F1, F2) to derive said substantially absolute grain loss indication therefrom. A harvesting machine according to any of the preceding claims, characterized in that it further also comprises display means (38) for displaying the substantially absolute grain loss indication. A harvesting machine according to any of the preceding claims, characterized in that convertor means (32-34; 43-45) are associated with the grain separation detector means (S1-S5/S1'-S3'), respectively the further detector means (S11-S14) for converting the output signals thereof to digital form for application to the processor means (37). A harvesting machine according to claim 20, characterized in that: the convertor means (32-34; 43-45) comprise means (32; 43) for converting the detector output signals into pulsed signals and counter means (33; 44) for counting the pulsed signals received from the pulsing means (32; 43) and multiplexer means (35) are provided which access all counter means (33; 44) in rotation. A harvesting machine according to claim 21, characterized in that the multiplexer means (35) access all counter means (33; 44) every second. A harvesting machine according to claim 21 or 22, characterized in that a buffer means (34; 45) is associated with each counter means (33; 44) into which the counts of the respective counter means (33; 44) are dumped when the latter are reset. A method of measuring grain loss from the threshing and separating mechanism (9) and/or the cleaning apparatus (12) of a harvesting machine; said method being characterized in that it comprises the steps of : detecting grain separation rates at at least two spaced apart locations along the length of the flow path of crop material through said threshing and separating mechanism (9) and/or at at least two spaced apart locations along the length of the flow path of crop material through said cleaning apparatus (12); producing output signals representative of said grain separation rates at said locations within the machine; applying said grain separation output signals against at least one algorithm (A) stored within processor means (37) and expressed in the form of a selected ratio of said output signals and deriving a substantially absolute indication of said grain loss from said at least one algorithm (A). A method according to claim 24, characterized in that it comprises the further steps of : detecting at least one operating condition parameter of said harvesting machine; producing a further output signal representative of the or each detected operating condition parameter; and using said further output signal or signals in the processor means (37) when deriving said substantially absolute indication of grain loss from said at least one algorithm (A). A method according to claim 25, characterized in that said deriving step includes the further step of selecting, in accordance to the operating condition parameter or parameters determined from said parameter detecting step, one algorithm (A) from a plurality of algorithms (A) stored in the processor means (37) for utilization in determining said substantially absolute grain loss indication.

Inventors: STRUBBE GILBERT J I, STRUBBE, GILBERT J.I.
Applicants: FORD NEW HOLLAND NV, NEW HOLLAND BELGIUM N.V.
Application year: 1988
Main classification: A01D41
IPC codes: A01D41