Patent Publication Number: US-8967728-B2

Title: Method of controlling a miner to cause wobble in the cutting heads

Description:
RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional Patent Application No. 61/435,027, filed Jan. 21, 2011, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     Embodiments of the invention relate to methods and systems for controlling a miner, such as a continuous miner. 
     SUMMARY OF THE INVENTION 
     A continuous miner typically includes a solid cutter drum or head that includes multiple sections. A recess, however, is formed between adjacent cutter head sections. The recess is caused by the web of the cutter head gear case where the gearing comes through to drive the cutter drum. Cutter bits included on the cutter head typically cannot reach material that enters the recess and, therefore, cannot break up material accumulating in the recess. The material left in the recess is often called the core. If the material being cut is soft, a core breaker installed in the recess typically can break the core away. However, if the material is hard, a core breaker has trouble breaking the core and the miner cannot sump into the material as effectively. 
     Accordingly, embodiments of the invention provide systems and methods for controlling a miner. One system varies the speed of left and right tram systems included in a continuous miner to make the cutter head alternate back and forth (e.g., left and right) while sumping into material. This alternating or “wobble” motion by the cutter head helps break up the core accumulating in the recess, which makes the miner more productive, especially when cutting hard material. Also, using the “wobble” motion may allow a miner to use different types of cutter heads rather than ryperveyor style cutters, such as drum style cutter heads. 
     One embodiment of the invention provides a system for controlling a miner. The system includes a cutter head, left and right tram systems, and a cutter head controller. The cutter head includes a plurality of bits and a plurality of sections defining at least one recess. The left and right tram systems are configured to move the miner, and the cutter head controller is configured to vary a current speed of at least one of the left tram system and the right tram system to cause the cutter head to alternate back and forth to bring the plurality of bits into engagement with material accumulating within the least one recess. 
     Another embodiment of the invention provides a computer-implemented method for controlling a miner, wherein the miner includes a cutter head including a plurality of bits and at least one recess, left and right tram systems configured to move the miner, and a cutter head controller. The method includes (a) setting, with the cutter head controller, an adjustment variable; (b) adjusting, with the cutter head controller, a current speed of at least one of the left tram system and the right tram system based on the adjustment parameter; (c) varying, with the cutter head controller, the adjustment parameter; and (d) repeating (b)-(c) to cause the cutter head to alternate back and forth to bring the plurality of bits into engagement with material accumulating within the least one recess. 
     Yet another embodiment of the invention provides non-transitory computer-readable medium encoded with a plurality of processor-executable instructions for controlling a miner, wherein the miner includes a cutter head including a plurality of bits and at least one recess and left and right tram systems configured to move the miner. The instructions include (a) setting an adjustment parameter; (b) adjusting a current speed of at least one of the left tram system and the right tram system based on the adjustment parameter; (c) varying the adjustment parameter; and (d) repeating steps (b)-(c) to cause the cutter head to alternate back and forth to bring the plurality of bits into engagement with material accumulating within the least one recess. 
     Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are perspective views of a cutter head of a continuous miner including core breakers according to one embodiment of the invention. 
         FIG. 2  is a front view of the cutter head of  FIGS. 1A and 1B . 
         FIG. 3  is a top view of the cutter head of  FIGS. 1A and 1B  in operation where core in recesses between the sections of the cutter head is not cut. 
         FIG. 4  is a top view of the cutter head of  FIGS. 1A and 1B  in operation where the left and right tram speed is varied to cut the core left in the recesses. 
         FIG. 5  schematically illustrates a cutter head controller for the cutter head of  FIGS. 1A and 1B . 
         FIG. 6  is a flow chart illustrating a method performed by the cutter head controller of  FIG. 5  to vary the left and right tram speed. 
         FIG. 7  illustrates a waveform according to one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein are meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. 
     In addition, it should be understood that embodiments of the invention may include hardware, software, and electronic components or modules that, for purposes of discussion, may be illustrated and described as if the majority of the components were implemented solely in hardware. However, one of ordinary skill in the art, and based on a reading of this detailed description, would recognize that, in at least one embodiment, the electronic based aspects of the invention may be implemented in software (e.g., stored on non-transitory computer-readable medium). As such, it should be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be utilized to implement the invention. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the invention and that other alternative mechanical configurations are possible. 
       FIGS. 1A and 1B  illustrate a cutter drum or head  10  of a continuous miner  12  according to one embodiment of the invention. As shown in  FIG. 1A , the cutter head  10  includes multiple sections  14  and each section  14  includes multiple bits  15 . Between adjacent sections  14  is a core breaker (“CB”)  16 . Each CB  16  is positioned within a recess  18  formed between the cutter head sections  14  (see  FIG. 2 ). The recess  18  is formed by the web of a cutter head gear case where the gearing comes through to drive the cutter head  10 . As described above, the bits  15  cannot cut material entering the recesses  18 , and the material left in the recesses  18  is often referred to as the core. For example, as shown in  FIG. 3 , core material (represented by triangles  20 ) entering the recesses  18  are out of reach of the bits  15  on the cutter head  10 . Therefore, the core  20  accumulates in the recesses  18  and is not cut by the bits  15 . If the core is made up of a soft material, the CB  16  positioned within each recess  18  can break up the core. However, if the core is made of harder material, the CB  16  can have trouble breaking the core, which impacts the performance of the miner  12 . 
     As described in more detail below with respect to  FIG. 6 , when the CB  16  cannot effectively break up the core accumulating in the recesses  18 , the cutter head  10  can alternate back and forth (e.g., left to right) when sumping into the material. This alternating or “wobble” movement allows the bits  15  to come into contact with the core  20  in the recesses  18 . To perform this alternating movement, the left and right tram speeds of the cutter head  10  can be varied over a predetermined period of time to move the cutter head  10  to the left and the right as the miner  12  trams forward. 
     In particular, the continuous miner  12  includes a tram system including a track chain on each side of the miner  12  that can each be independently controlled to operate at the same or at different speeds. For example, as shown in  FIG. 1B , the miner  12  can include a right tram system  21  including a right track chain  22 . The miner  12  can include a corresponding left tram system including a left track chain on the opposite side of the miner  12 . When set to the same speeds, the tram systems move the cutter head  10  in a forward direction. However, each tram system can move the cutter head  10  to the left or to right depending on whether the speed of the tram system is increased or decreased. For example, if the speed of the right tram system is decreased to be less than the speed of the left tram system, the left tram system is moving faster, which causes the cutter head  10  to move to the right. Similarly, if the speed of the left tram system is decreased to be less than the speed of the right tram system, the right tram system is moving faster, which causes the cutter head  10  to move to the left. By varying the left and right tram speeds while the miner  12  sumps into material, an alternating or “wobble” motion is created with the cutter head  10 , which helps break up the core left in the recesses. In particular, using the “wobble” motion allows the core  20  to be attacked from both sides (as shown by the arrows in  FIG. 4 ) to help break the core  20  with the cutter bits  15  to the left and right of the core  20  rather than straight on with a core breaker  16 . In other embodiments, the speeds of particular drums or sections of the cutter head  10  can also be varied to cause the cutter head  10  to alternate back and forth. 
     It should be understood that the cutter head  10  can be controlled by a cutter head controller. The cutter head controller can include electrical components, mechanical components, software components, or combinations thereof that control the operation of the cutter head  10 .  FIG. 5  schematically illustrates a cutter head controller  30  according to one embodiment of the invention. It should be understood that  FIG. 5  illustrates only one example of components of a cutter head controller  30  and that other configurations are possible. As shown in  FIG. 5 , the controller  30  includes a processor  32 , computer-readable media  34 , and an input/output interface  36 . The processor  32 , computer-readable media  34 , and input/output interface  36  are connected by one or more connections  38 , such as a system bus. It should be understood that although only one processor  32 , computer-readable media module  34 , and input/output interface  36  are illustrated in  FIG. 5 , the controller  30  can include multiple processors  32 , computer-readable media modules  34 , and input/output interfaces  36 . It should also be understood that the cutter head controller  30  can be combined with other controllers. For example, the cutter head controller  30  can be part of an overall controller for the miner  12 . 
     The processor  32  retrieves and executes instructions stored in the computer-readable media  34 . The processor  32  can also store data to the computer-readable media  34 . The computer-readable media  34  can include non-transitory computer readable medium and can include volatile memory, non-volatile memory, or a combination thereof. In some embodiments, the computer-readable media  34  includes a disk drive or other types of large capacity storage mechanism. 
     The input/output interface  36  receives information from outside the controller  30  and outputs information outside the controller  30 . For example, the input/output interface  36  can transmit signals, data, instructions, and queries to mechanical and electrical equipment located outside the controller  30  that operate and control the cutter head  10  or other components of the miner  12 . 
     The instructions stored in the computer-readable media  34  can include various components or modules configured to perform particular functionality when executed by the processor  32 . For example, the computer-readable media  34  can include a core busting module  40 , as shown in  FIG. 5 . The core busting module  40  can be executed by the processor  32  to vary the left and right tram speeds of the cutter head  10  while the miner  12  trams forward. As described above, varying the tram speeds causes the cutter head  10  to alternate back and forth while sumping forward into the material. This alternating or “wobble” motion helps break up the core  20  accumulating in the recesses  18 . As described below with respect to  FIG. 6 , an amplitude parameter can be used to determine the degree of the alternating movement of the cutter head  10 , which determines how much the left and/or right tram speed is varied. A period parameter can also be used to determine the period of the “wobble” movement, which determines how long it takes for one “wobble” cycle to complete. 
       FIG. 6  is a flow chart illustrating a method performed by the controller  30  when the core busting module  40  is executed according to one embodiment of the invention. As shown in  FIG. 6 , the method starts by determining if an operator of the miner  12  has issued a tram command (at  50 ). When the operator issues a tram command, the method determines whether an amplitude parameter is set to a value greater than zero (at  52 ). Initially, when the core busting module  40  is loaded or executed, the amplitude parameter can be set to 0 and a period parameter can be set to 1 second. If the core becomes a problem and an operator desires to enable the “wobble” feature, an operator can set the amplitude parameter to a non-zero value via a graphical display (e.g., on the miner  12  or on a remote control station or device for the miner  12 ). 
     An operator can then set the amplitude parameter to a value indicating a degree of “wobble” the operator desires. The operator can also set the period parameter in a similar fashion. In some embodiments, the amplitude parameter can be set between 0 and 30 and can be set as a percentage of the maximum cutting speed of the miner  12 . The value of one or both of the parameters can also be automatically set by the module  40  based on the operation of the miner  12  or various sensors detecting various parameters of the core. For example, the core busting module  40  can automatically determine a suggested amplitude and/or period parameter and can display the suggested parameter(s) to an operator for verification or manual override. 
     If the amplitude parameter has a value greater than zero, the method determines if the tram systems for the miner  12  are moving in a forward direction (at  54 ). If the tram systems are moving forward, the miner  12  is sumping forward into the material and the “wobble” feature should be started to handle core material accumulating in the recesses  18 . Therefore, in some embodiments, the method generates a waveform (at  56 ), such as the triangle waveform illustrated in  FIG. 7 . As described below, the waveform is used to vary the speed of the left and right tram systems over a predetermined period of time to move the cutter head  10  to the left and to the right (e.g., “wobble” the cutter head  10 ) to break up the core. The module  40  generates the waveform based on the values of the amplitude parameter and the period parameter (i.e., as set by the operator or the module  40 ). For example, the waveform has a period and a current amplitude at various time intervals over the waveform period. The maximum amplitude of the triangle waveform can be approximately the value of the amplitude parameter, and the period of the waveform can be approximately the value of the period parameter (data  60 ). 
     Alternatively, as shown in  FIG. 6 , if the operator has not issued a tram command (at  50 ), the amplitude parameter is not greater than zero (at  52 ), or the tram systems are not moving in a forward direction (at  54 ), the miner  12  is not operating in a condition where core material accumulating in the recesses  18  is an issue. Therefore, in this situation, an adjustment variable, which is used by the module  40  as described below to vary the tram speeds, is set to zero (at  58 ) and a triangle waveform is not generated. 
     After the waveform is generated, the waveform is used to vary the left and right tram speeds of the cutter head  10  over a predetermined period. For example, the period of the waveform sets the predetermined time period over which the tram speeds are varied (i.e., the time that the “wobble” movement is performed), and the adjustment variable is set to the current amplitude of the waveform at each time interval during the waveform period. Therefore, initially, after the waveform is generated, the adjustment variable is set to the amplitude of the waveform at an initial time interval (e.g., the start of the waveform). Then, at each time interval over the period of the waveform, the value of the adjustment variable is reset to the amplitude of the waveform at that time interval. 
     At each time interval, the adjustment variable is then added to or subtracted from the current speed of the left or right tram to either increase or decrease the current speed of the left or right tram speed by the current amplitude of the waveform. When this is performed over the period of the waveform, the cutter head  10  alternates back and forth in a “wobble” motion that brings the bits  15  into engagement with the core  20 . As the bits  15  attack the core  20  from the left and from the right during the “wobble” motion, the core  20  is cut and broken up, which allows the miner  12  to continue to effectively tram forward. 
     For example, as shown in  FIG. 6 , after the triangle waveform is generated (at  56 ) or the core breaker adjustment is set to zero (at  58 ), the method determines if the adjustment variable has a value greater than zero (at  62 ). As described above, if core busting is not needed, the adjustment variable is set to zero (at  58 ), but if core busting is desired, the adjustment variable is to the amplitude of the waveform at the current time interval. Therefore, if the adjustment variable has a value greater than zero, the module  40  subtracts the value of the adjustment variable from the current speed of the left tram to decrease the speed of the left tram by the value of the adjustment variable (at  64 ). 
     Alternatively, if the adjustment variable is not greater than zero (at  62 ), the method determines if the adjustment variable has a value less than zero (at  66 ). If the value of the adjustment variable is less than zero, the module  40  adds the negative value of the adjustment variable from the current speed of the right tram to decrease the speed of the right tram by the value of the adjustment variable (at  68 ). Therefore, if the adjustment variable has been set to zero (at  58 ), no adjustment is made to the current speed of the left or right tram by the core busting module  40 . However, if the adjustment variable is set to a non-zero value, either the left or right tram speed is adjusted based on the adjustment variable to make one of the tram speeds greater than the other, which causes the cutter head  10  to either move to the left or to the right. It should be understood that subtracting the value of the adjustment variable from one tram is equivalent to adding the value of the adjustment variable from the other tram. For example, at  68 , the value of the adjustment variable can either be added to the current speed of the right tram or subtracted from the current speed of the left tram to achieve a similar result (i.e., the cutter head  10  moves to the right). However, in some embodiments, it may be more efficient and/or safer to slow down a tram speed rather than speed up a tram speed. 
     After the speed of the left or right ram is varied based on the adjustment variable, the value of the adjustment variable can be adjusted or reset to the amplitude of the waveform at the next or subsequent time interval of the waveform period. This process can be repeated for the period of the waveform, which causes the cutter head  10  to alternate back and forth to engage the bits  15  with the core accumulating in the recess  18 . After the entire waveform has been applied, the module  40  can repeat the method illustrated in  FIG. 6  and a new waveform can be generated and applied if needed. Alternatively, the waveform initially generated by the module  40  can be reused or reapplied one or more times. 
     As previously mentioned, varying the speed of the left and right trams causes the cutter head to alternate back and forth. This “wobble” motion by the cutter head helps break up the core accumulating in the recesses  18 , which makes the miner  12  more productive, especially when cutting hard material. Also, using the “wobble” motion may allow a miner  12  to use different types of cutter heads rather than ryperveyor style cutters, such as drum style cutter heads. 
     Also, it should be understood that generating a waveform is only one way to vary or alternate the speeds of the tram systems. For example, the trams speeds can be varied based on a constant value that can be applied for a predetermined period of time to each of the tram systems. For example, initially the right tram speed can be decreased by a desired amount for a predetermined period of time (which moves the cutter head  10  to the left) and then the left tram speed can be decreased by the desired amount for a predetermined period of time (which moves the cutter head  10  to the right). This can be repeated as much as needed to effectively break up the core accumulating in the recesses  18 . Alternatively, the speeds of each tram system can be adjusted using different amounts (e.g., set automatically or manually) and/or the speed of each tram system can be adjusted for a different period of time. This uneven alternating motion can create an uneven “wobble” where the cutter head  10  moves in one direction (i.e., the left or the right) more than in the opposite direction, which can move the entire miner  12  either to the left or to the right over an extended period of time. Also, in some embodiments, an operator can use a button or switch on a display to manually increase or decrease one of the tram speeds a predetermined amount for as long as the operator holds down or engages the button or switch. 
     Various features and advantages of the invention are set forth in the following claims.