Abstract:
A method for controlling operation of a harvesting machine includes using a sensor unit to sense at least one state variable of a rolling-element bearing during operation of the harvesting machine and sending the at least one sensed variable to at least one evaluation unit, analyzing the at least one sensed variable in the at least one evaluation unit and generating at least one analysis result, and starting a process operation based on the at least one analysis result, wherein the process operation includes controlling at least one operating parameter of the harvesting machine and wherein the controlling and the sensing of the sensor unit form a closed loop control circuit.

Description:
CROSS-REFERENCE 
     This application is the U.S. National Stage of International Application No. PCT/EP2011/058351 filed on Mar. 23, 2011. 
     TECHNICAL FIELD 
     The present invention generally relates to a method and system for controlling operation of the system, such as an agricultural harvesting machine, based upon data from a sensor of a rolling-element bearing. 
     RELATED ART 
     A method is known in which a sensor unit senses a state variable of a rolling-element bearing and sends data of the sensing to at least one evaluation unit which analyzes the data. 
     SUMMARY 
     A method, in particular a harvesting machine control method, is proposed, in which a sensor unit senses at least one state variable of a rolling-element bearing and sends data of the sensing to at least one evaluation unit which analyzes the data, wherein depending on at least one result which is obtained in the analysis, at least one process operation is started. An “evaluation unit” shall in particular be understood to mean a unit which includes a computational unit, a storage unit, and an operating program stored in the storage unit. An “analyzing of the data” by the evaluation unit shall in particular be understood to mean that the evaluation unit preferably checks, based on the data, whether a temperature of the rolling-element bearing is so high that a further use of the rolling-element bearing would lead to damage of the rolling-element bearing, and/or the evaluation unit preferably checks, based on the data, whether vibrations are occurring in the rolling element bearing, in particular in a radial direction of the rolling element bearing, from which a defect or damage of the inner ring and/or of the outer ring and/or of a rolling element and/or of the rolling element cage of the rolling-element bearing can be inferred. A high efficiency can be achieved using an inventive design. In particular, measures can be taken against an overloading or an impending failure of the rolling-element bearing. In particular, it can be prevented that a machine malfunctions during an operating process, in particular a harvesting machine during a harvesting operation, due to a failure of the rolling-element bearing, wherein costs can be saved by the prevention. 
     Further, it is proposed that the process operation is at least a controlling of at least one operating parameter of a harvesting machine which controlling, together with the sensing of the sensor unit, form a closed loop control circuit. Thus a safeguarded operation can automatically be achieved. 
     The at least one operating parameter is preferably a width of a material conveyance channel of the harvesting machine and/or a driving speed of the harvesting machine. A “width” of a material conveyance channel shall be understood in particular to mean a minimum width of the material conveyance channel that prevails with reference to an entire length of extension of the material conveyance channel. State variables of the rolling-element bearing can thereby be effectively influenced. 
     The process operation is advantageously a notification operation, wherein information about a risk of damage of the rolling-element bearing is reported to an operator of a harvesting machine and/or at least a proposed action is reported to the operator, which leads to a reduction of a risk of damage of the rolling-element bearing, and/or it is reported to the operator when the bearing is estimated to fail. In this way an operation that safeguards the rolling-element bearing can be achieved. 
     The method preferably takes place in real time. That the method takes place in “real time” shall in particular be understood to mean that the method takes place within a time interval of three seconds, preferably a tenth of a second, and particularly preferably within a hundredth of a second. A fast protection of the rolling-element bearing can thereby be achieved. 
     In addition, it is proposed that the at least one state variable is a rotational speed of the rolling-element bearing and/or at least one vibration frequency of the rolling-element bearing and/or a temperature of the rolling-element bearing and/or a torque acting on a bearing ring of the rolling-element bearing. In this way, impending or existing damage of the rolling element bearing can be inferred in a simple manner. 
     Advantageously, the rolling-element bearing is a part of a harvesting machine, and additional data from additional sensor units in additional harvesting machines are analyzed, and at least one signal is sent to at least one harvesting machine based on at least a plurality of analysis results of data of a plurality of harvesting machines. An efficient simultaneous operation of a plurality of harvesting machines can thereby be achieved. 
     Furthermore, a system is proposed which is provided to perform the method. “Provided” shall be understood in particular to mean specifically designed and/or specifically equipped and or specifically programmed. A high efficiency can thereby be achieved. 
     The system preferably includes at least a part of a harvesting machine which includes the rolling-element bearing, wherein the system includes an additional part which is different from a part of a harvesting machine and includes the evaluation unit. An efficient construction can thereby be achieved. 
     In addition, a harvesting machine is proposed which is provided to perform the method. In this way a high efficiency can be achieved. 
     Further advantages will become apparent from the following description of the drawings. Exemplary embodiments of the invention are shown in the drawings. The drawings, the description, and the claims contain numerous features in combination. The person skilled in the art will also advantageously consider the features individually and in further meaningful combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a forage harvester which performs an inventive method, 
         FIG. 2  shows a schematic view of a cut-material conveyance path in a self-propelled part of the forage harvester, and 
         FIG. 3  schematically shows an integration of the forage harvester into a control method that involves a plurality of harvesting machines. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a system which is provided to perform an inventive method that takes place in real time. The system is a harvesting machine  16  and is formed as a forage harvester. The harvesting machine includes a chopping mechanism  26 , which is provided to chop crop material, e.g. corn plants, and which can be decoupled in a non-destructive manner and without tools from a self-propelled part of the forage harvester. During operation, crop material (e.g., corn stalks) is supplied through a conveyance channel  28  to a cutting drum  30  which cuts the supplied crop material into small pieces. In principle, it is conceivable to replace the conveyance channel  28  with feed rollers. The small pieces reach a first and a second kernel processing roll  32 ,  34 , which are part of the self-propelled part of the forage harvester and which are provided to squeeze corn kernels such that their surfaces burst open. The spacing of the kernel processing rolls  32 ,  34  forms a minimum width  18  of a material conveyance channel  20 , through which the crop material is transported. After the crop material has passed through the kernel processing rolls  32 ,  34 , it reaches an accelerator roll  36 , which accelerates the crop material such that it is discharged through a spout (not shown) of the self-propelled part of the forage harvester. 
     The self-propelled part of the harvesting machine includes a rolling-element bearing  12  which supports the kernel processing roll  32 . A sensor unit  10  of the self-propelled part of the harvesting machine is disposed on the rolling-element bearing  12 , which sensor unit  10  measures, during the operation, the rotational speed of an inner ring of the rolling-element bearing  12  relative to an outer ring of the rolling-element bearing  12 . Furthermore, the sensor unit  10  measures the temperature of the rolling-element bearing  12  and vibrations of the rolling-element bearing  12  occurring in radial directions of the rolling-element bearing  12 , i.e. amplitudes and frequencies of the vibrations. In addition, the sensor unit  10  measures a torque which acts on the rolling-element bearing  12  during operation. The sensor unit  10  wirelessly sends all sensed data to an evaluation unit  14  of the harvesting machine  16 . The data can also be sent via cable. The evaluation unit  14  includes a computational unit, a storage unit, and an operating program. The evaluation unit  14  analyzes the data using an algorithm which is stored in the storage unit. The evaluation unit  14  recognizes when the temperature of the rolling-element bearing  12  has reached a critical value which, during a further operation of the rolling-element bearing  12  at the same operating conditions, would cause the rolling-element bearing  12  to be damaged. The recognition is effected by the evaluation unit  14  by comparing the temperature sensed by the sensor unit  10  to a temperature stored in the evaluation unit  14 . If the sensed temperature is above the stored temperature, then the critical value of the temperature is present. In a similar manner, an evaluation of the vibrations sensed by the sensor unit  10  is effected by the evaluation unit  14 . The evaluation of the vibrations sensed by the sensor unit  14  is prior art and known to the person skilled in the art. The following formulas for the so-called “bearing defect frequencies” are stored in the storage unit of the evaluation unit  14 , which formulas are known to the person skilled in the art: 
               B   ⁢           ⁢   P   ⁢           ⁢   F   ⁢           ⁢   O     =       n   60     *   z   *         D   pw     -       D   we     ⁢   cos   ⁢           ⁢   α         2   *     D   pw                         B   ⁢           ⁢   P   ⁢           ⁢   F   ⁢           ⁢   I     =       n   60     *   z   *         D   pw     +       D   we     ⁢   cos   ⁢           ⁢   α         2   *     D   pw                           B   ⁢           ⁢   S   ⁢           ⁢   F     =       n   60     *         D   pw   2     -       D   we   2     ⁢   cos   ⁢           ⁢   α           D   we     *     D   pw             ,       B   ⁢           ⁢   P   ⁢           ⁢   F     =     2   *   B   ⁢           ⁢   S   ⁢           ⁢   F                     F   ⁢           ⁢   T   ⁢           ⁢   F     =       n   60     *         D   pw     -       D   we     ⁢   cos   ⁢           ⁢   α         2   *     D   pw                 
Here n is the speed of the rolling-element bearing, z is the number of rolling elements in the bearing, D pw  is the rolling-element bearing cage diameter, D we  is the rolling-element diameter, and a is the contact angle. If the evaluation unit  14  recognizes frequencies in the data of the sensor unit  10  which match those calculated from the above formulas, then the evaluation unit  14  recognizes critical frequencies. If the evaluation unit  14  recognizes critical frequencies, then it causes a warning message for warning of a risk of damage of the rolling-element bearing  12  to be notified to the driver of the harvesting machine  16  in an optical display unit which is formed as a screen and which is disposed in a cockpit  38  ( FIG. 1 ) of the harvesting machine  16 . Furthermore, the display unit displays a proposed action which will lead to a reduction of the risk of damage. This proposed action can in particular be to drive the harvesting machine  16  at a lower speed. From the critical frequencies and an intensity of the occurring critical frequencies, the evaluation unit  14  can conclude therefrom in a known manner when the rolling-element bearing  12  is estimated to be fully defective and unusable in a further operation. This information is notified to the driver of the harvesting machine by the display unit.
 
     If the evaluation unit  14  recognizes a critical value of the temperature, then it causes a speed, at which the harvesting machine travels, to be reduced. Additionally or alternatively it can cause the width  18  to be enlarged. Furthermore, a controlling of the speed by the evaluation unit  14  together with the sensing of the sensor unit  10  can form a closed loop control circuit in such a manner that the temperature of the rolling-element bearing  12  is regulated to a specific, non-critical value by a controlling of the speed. In addition, a controlling of the width  18  by the evaluation unit  14  together with the sensing of the sensor unit  10  can form a closed loop control circuit in such a manner that the temperature of the rolling-element bearing  12  is regulated to a specific, non-critical value by a controlling of the width  18 . A time period from a sensing of the sensor unit  10  to a controlling of the speed caused thereby is smaller than a half-second. 
     In principle, the evaluation unit may be disposed outside the harvesting machine in a control center and may wirelessly send data back to the harvesting machine  16 . Furthermore, the sensor unit  10  and the evaluation unit  14  can be retrofitted onto an existing harvesting machine  16 . 
     The sensor unit  10  is integrated in the bearing seat of the rolling-element bearing  12 . At least a part of the sensor unit  10  can also be integrated in the shaft. 
     It is conceivable in particular for a programming of the evaluation unit  14  to at least partially use the program “@ptitude Decision Support.” 
     In principle the described method may also be used on other rolling-element bearings of the harvesting machine  16 , such as on rolling-element bearings of the cutting drum  30  and of the accelerator roll  36 . In this case the display unit can display the state and/or a risk of damage of each of the bearings in question. In particular, harmful influences of silage juices and dust can be recognized and/or compensated by the described method. 
     In  FIG. 3  an alternative exemplary embodiment is shown. Components, features, and functions remaining substantially identical are generally numbered with the same reference numbers. However, the letter “a” has been added to the reference numbers of the exemplary embodiment in  FIG. 3  to differentiate the exemplary embodiments. The following description is essentially limited to the differences to the exemplary embodiment in  FIG. 1  to  FIG. 2 , wherein with respect to components, features, and functions remaining the same, reference can be made to the description of the exemplary embodiment in  FIG. 1  to  FIG. 2 . 
       FIG. 3  shows an integration of a harvesting machine  16   a  into a control method that involves a plurality of harvesting machines  16   a ,  24   a . In the control method, in each of the harvesting machines  16   a  formed as forage harvesters, data of a rolling-element bearing  12 , which the harvesting machine  16   a ,  24   a  in question includes, obtained in the above-described manner by the sensor units  10   a ,  22   a  is sent to an evaluation unit  14   a  which is disposed in a control center. The evaluation unit  14   a  analyzes the data. If a risk of damage exists for rolling-element bearings  12  of different harvesting machines  16   a ,  24   a , then the evaluation unit  14   a  can deactivate those machines  16   a ,  24   a  having the greatest risk of damage and leave those machines active which have an existing but comparatively small risk of damage. The harvesting machines  16   a ,  24   a  that will be deactivated are thus deactivated depending on the states of the rolling-element bearings in all machines. This is particularly advantageous when the harvesting machines  16   a ,  24   a  are working the same field, and the field must be completely worked in a given amount of time. 
     It is conceivable that the evaluation unit  14   a  stores the data sent to it, so that the data can be considered in a redesign of the harvesting machines. In this way it can be avoided that a too-conservative construction design leads to an inefficient machine use. Furthermore, by storing the data, a use-dependent planning of maintenance work can be effected. 
     REFERENCE NUMBER LIST 
     
         
           10  Sensor unit 
           12  Rolling-element bearing 
           14  Evaluation unit 
           16  Harvesting machine 
           18  Width 
           20  Material conveyance channel 
           22  Sensor unit 
           24  Harvesting machine 
           26  Chopping mechanism 
           28  Conveyance channel 
           30  Cutting drum 
           32  Kernel processing roll 
           34  Kernel processing roll 
           36  Accelerator roll 
           38  Cockpit