Abstract:
A system for an excavating machine comprises a control system operating aspects of the excavation machine; and a monitoring system receiving inputs from one or more sensors determining if the excavating machine is in a first state or a second state. In operation, if the excavating machine is in the first state, then the control system enables the excavating machine to perform a first action; or if the excavating machine is in the second state, then the control system disable the excavating machine to perform the first action.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/016,856, filed 25 Jun. 2014, the entire contents and substance of which is hereby incorporated by reference as if fully set forth herein. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    Aspects of the present invention relate to excavating machines and, more particularly, to dynamic motion optimization for excavating machines. 
         [0004]    2. Description of Related Art 
         [0005]    In general, excavating machines are large and expensive machines that are used to excavate large quantities of overburden and minerals. These excavating machines often include multiple motors controlling the operation of the various components of the excavating machine. In order to operate, excavating machine operators use a set of controls to simultaneously operate the multiple motors. Due to the size of the excavating machines and the complexity of the operation, the operators must be highly trained to properly and safely operate the excavating machines. 
         [0006]    Despite extensive training, operators routinely make errors in the operation of the excavating machines, which can cause damage to the excavating machine and lead to down-time of the excavating machine and increased cycle time. The proficiency with which the operator can operate the excavating machine contributes significantly to the productivity of the excavating machine. 
       SUMMARY 
       [0007]    Aspects of the present invention relate to a dynamic motion optimization algorithm for an excavating machine that can reduce the likelihood that an operator error can cause damage to the excavating machine and lead to down-time of the excavating machine and increased cycle time. 
         [0008]    In exemplary embodiments, a control system of a excavating machine is configured to prevent a swing operation while the excavating machine is engaged in the digging motion, configured to limit crowd speed based on crowd angle, configured to limit hoist speed based on load in a dipper, and/or configured to prevent the excavating machine from stalling while excavating. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of an excavating machine, i.e., a dragline machine, in accordance with an exemplary embodiment of the present invention. 
           [0010]      FIG. 2  is a perspective view of another excavating machine, i.e., an electric rope shovel machine, in accordance with an exemplary embodiment of the present invention. 
           [0011]      FIGS. 3A, 3B and 3C  depict a swing cycle of the excavating machine between a dig location and a dumping location, in accordance with exemplary embodiments of the present invention; and 
           [0012]      FIG. 4  is a block diagram of a control system for the excavating machine, in accordance with an exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    To facilitate an understanding of embodiments, principles, and features of the present invention, they are explained hereinafter with reference to implementation in illustrative embodiments. In particular, they are described in the context of systems and methods for dynamic motion optimization for excavating machines. 
         [0014]    Embodiments of the present invention, however, are not limited to use in the described systems or methods. 
         [0015]    The components and materials described hereinafter as making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components and materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of embodiments of the present invention. 
         [0016]    Although the systems and methods that may be described herein may be directed to either a dragline excavating machine or an electric rope shovel machine, the technology described, including the systems and methods herein, can also be provided, used, operated and/or implemented in various other excavating machines. 
         [0017]    Referring now to  FIG. 1 , a portion of an excavating machine  1 , here a dragline excavating machine, is illustrated. The dragline excavating machine  1  includes a base, which rests upon the ground and supports a machinery house  3 . The machinery house  3  carries a boom  4  projecting upwardly from the lower front of the house  3 . The boom  4  includes a foot, which is connected to the house by a connection member, for example and not limitation foot pins  5 . In exemplary embodiments, the boom  4  is held at the desired angle of inclination by means of suspension cables  6  extending from the boom  4  to an A-frame  7  carried on top of the house  3 . An excavating member, for example bucket  19 , is suspended by hoist ropes  8 , which pass over sheaves  9  on the mast to wind on hoist drums  10  in the house. 
         [0018]    During operation, the bucket  19  can be moved toward the dragline excavating machine  1  by drag ropes  11  passing over fairleads  12  near the boom foot pins  5  and onto drag drums  13  in the machinery house  3 . The dragline excavating machine  1  may be mounted on a walking mechanism  15 , which allows the dragline excavating machine  1  to be moved from one location to another. The walking mechanism  15  includes a shoe that is driven internally by drive systems including an internal motor and gear assembly, in a conventional manner. 
         [0019]    Dragline excavating machines are primarily used to dig below their working level and to dump at an elevated level. The digging cycle consists of five components: (1) drag to fill, (2) hoist and swing to dump, (3) dump, (4) lower and return swing, and (5) position bucket. 
         [0020]    The dragline cycle begins with the bucket lowered in a pit and positioned to penetrate the bank. Dragging it into the face fills the bucket. Once filled, hoisting and drag pay out commences almost immediately, followed by swinging as the bucket clears the trench. As the bucket swings and climbs, proper tension between the hoist and drag controls holds the bucket in the carry position. As the dumping location is approached, the swing control is reversed to stop swinging and the drag is allowed to pay out until the bucket is tilted and dumps its load. Due to the swing inertia of the machine, the direction of swing will not change for several seconds after the controls are reversed, giving the bucket time to dump without delay. During the return swing, the hoist is lowered and the drag is reeved in so as to begin the positioning of the bucket for the next load. The swing control is reversed to stop the swing motion, and then neutralized as the bucket settles into position. The proficiency with which these functions are carried out contributes significantly to the productivity of the machine. 
         [0021]      FIG. 2  depicts another excavating machine, i.e., an electric rope shovel machine  100 . The electric rope shovel machine  100  includes tracks  105  for propelling the electric rope shovel machine  100  forward and backward, and for turning the electric rope shovel machine  100  (e.g., by varying the speed and/or direction of the left and right tracks relative to each other). The electric rope shovel machine  100  includes a machine house  110  and a cab  115 . The machine house  110  is able to swing or swivel about a swing axis  125 , for instance, to move from a digging location to a dumping location. The electric rope shovel machine  100  also includes a handle  135  supporting an excavating member, in this case a bucket or dipper  140 . The dipper  140  includes a door  145  for dumping contents within the dipper  140 . The electric rope shovel machine  100  also includes suspension cables  150  coupled between the machine house  110  and boom  130  for supporting the boom  130 ; a hoist cable  155  attached to a drum within the machine house  110  for winding the cable  155  to raise and lower the dipper  140 ; and a crowd motor for extending and retracting the handle  135 . 
         [0022]    When the tracks  105  of the electric rope shovel  100  are static, the dipper  140  is operable to move based on three control actions: (1) hoist, (2) crowd, and (3) swing. 
         [0023]    As noted above, the hoist control raises and lowers the dipper  140  by winding and unwinding hoist cable  155 . In exemplary embodiments, the hoist cable  155  is wound on a large drum driven by an AC motor, is routed through sheaves (pulleys), and supports the bucket assembly from the boom  130 . The crowd control extends and retracts the position of the handle  135  and dipper  140 . The swing control rotates the machine house  110  relative to the swing axis  125  (see, e.g.,  FIGS. 3A-C ). By skillful maneuvering of the hoist cables and the crowd handle assembly, the bucket is controlled for filling with overburden/minerals and dumping on a haul truck for excavation purposes. Before dumping its contents, the dipper  140  is maneuvered to the appropriate hoist, crowd, and swing position to 1) ensure the contents do not miss the dump location  170 ; 2) the door  145  does not hit the dump location  170  when released; and 3) the dipper  140  is not too high such that the released contents would damage the dump location  170  or cause other undesirable results. 
         [0024]      FIGS. 3A-3C  depict exemplary swing angles of the electric rope shovel machine  100  moving from a dig position to a dump position. For reference purposes, a boom axis  205  and dump position axis  210  are overlaid on  FIGS. 3A-3C , with the swing axis  125  being the approximate intersection of the boom axis  205  and dump position axis  210 . The angle between the handle axis  205  and the dump position axis  210  is referred to as θ. In  FIG. 3A , the dipper  140  digs into bank  215  at a dig location  220 , and θ=θ 1 . After digging, the electric rope shovel  100  begins to swing the boom  130  towards the dump location  170 . In  FIG. 3B , the boom  130  is about mid-way through the swing-to-dump, and θ=θ 2 . In  FIG. 3C , the boom  130  has stopped over the dump location  170  and the door  145  is released to dump the materials within the dipper  140  into the dump location  170 , with θ=θ 3 . 
         [0025]    Referring now to  FIG. 4 , a block diagram of a control system  300  for an electric rope shovel machine in accordance with an exemplary embodiment is shown. As illustrated the control system  300  includes a processor  302 , one or more sensors  304 , a user interface  306 , and one or more motors  308 . In exemplary embodiments, the processor  302  receives input signals from both the user interface  306  and the one or more sensors  304 , and responsively controls the operation of the one or more motors  308 . 
         [0026]    In exemplary embodiments, the processor  302  may be a digital signal processing (DSP) circuit, a field-programmable gate array (FPGA), an application specific integrated circuits (ASICs) or the like. The processor  214  can be many custom made or commercially available processors, a central processing unit (CPU), an auxiliary processor among several processors, a semiconductor based microprocessor (in the form of a microchip or chip set), or generally any device for executing instructions. The processor  302  may include a memory and a transceiver. The processor  302  may communicate with the plurality of sensors  304  wirelessly or via wired connections. 
         [0027]    The one or more sensors  304  may include a wide variety of sensors disposed in various locations carried by the electric rope shovel machine and are used to monitor a wide variety of operating conditions of the electric rope shovel machine. The operating conditions of the electric rope shovel machine include, but are not limited to, the position of the handle, the position of the dipper, the weight of the material in the dipper, the torque on the handle, the swing position, the crowd speed, the hoist speed, a crowd angle, and the like. In exemplary embodiments, the processor  302  monitors the reading received from the one or more sensors  304  and can actively limit the operation of the one or more motors  308 . 
         [0028]    For example, with the dipper empty the maximum lower speed may be set to a first level and, with the dipper having over a threshold load, the maximum lower speed may be set to a second level that is lower than the first level. In such cases, processor  302  may determine the load in the dipper based on the readings from the one or more sensors  304  and the processor  302  may limit the maximum lower speed. That is, if the operator, via the user interface  308 , attempts to lower at maximum velocity the processor  302  may limit the maximum velocity based on the detected load. 
         [0029]    In exemplary embodiments, the control system  300  of the electric rope shovel machine is configured to prevent a swing operation while the electric rope shovel machine is excavating, as shown in  FIG. 3A . Preventing a swing operation of an excavating machine while the excavating machine is actively digging can prevent damage to the excavating machine. In exemplary embodiments, the processor  302  monitors the input signals received from the one or more sensors  304  and responsively determines if the dipper is engaged with a bank. Based on making the determination that the dipper is engaged with a bank, the processor  302  may set a dipper engaged condition or flag. In exemplary embodiments, upon the processor  302  receiving a swing command from the operator, for example via the user interface  308 , the processor  302  will check to see if the dipper engaged condition or flag indicates that the dipper is currently engaged with a bank. If the dipper is not currently engaged with a bank, the processor  302  will proceed to execute the swing command received. But if the dipper is currently engaged with a bank, the processor  302  will not execute the swing command. In exemplary embodiments, the processor  302  may be configured to provide a command over-ride alert in response to not executing a received swing command. The command over-ride alert may be displayed to the operator of the electric rope shovel machine to alert the operator that their command was overridden. In addition, the command over-ride alert may be logged and stored in the memory of the processor  302 , or it may be transmitted by the processor  302  to a separate piece of equipment. 
         [0030]    In exemplary embodiments, for example with a loaded dipper, the control system  300  of the electric rope shovel machine is configured to limit the crowd speed based on the crowd angle. As used herein, the term “crowd speed” means the speed at which the handle  135  is extended or retracted as shown in  FIG. 2 . As used herein the term “crowd angle” means the angle of the handle  135 , as shown in  FIG. 2 , relative to a vertical position. For example, the crowd angle of the handle  135  shown in  FIG. 2  is about 95°; a crowd angle of 0° would indicate that the handle  135  was perpendicular with the ground. In exemplary embodiments, the handle is extended and retracted by an AC motor and the speed of the extraction and retraction, the crowd speed, is controlled by an operator via a user interface. In exemplary embodiments, the AC motor used to control the operation of the handle may not be capable of stopping the movement of the handle if the handle is moving at a crowd speed when the crowd angle is low due to the weight of the handle and the dipper. 
         [0031]    Accordingly, the control system  300  of the electric rope shovel machine is configured to limit the crowd speed based on the crowd angle. In exemplary embodiments, the processor  302  monitors one or more input signals received from the one or more sensors  304  and responsively calculates the crowd angle. In exemplary embodiments, the processor  302  limits the maximum crowd speed as a function of the calculated crowd angle. For example, as the crowd angle decreases the maximum crowd speed allowed by the processor  302  also decreases. In exemplary embodiments, by limiting the maximum crowd speed based on the crowd angle the processor  302  ensures that the control system  300  is capable of stopping the movement of the handle, which will help prevent damage to the dipper and the handle of the electric rope shovel machine. 
         [0032]    In exemplary embodiments, the control system  300  of the electric rope shovel machine is configured to limit the hoist speed based on the load in the dipper. As used herein, the term “hoist speed” means the speed at which the dipper  140  is raised or lowered, for example, as shown in  FIG. 2 . In exemplary embodiments, the dipper  140  is raised and lowered by an AC motor and the hoist speed is controlled by an operator via a user interface. In exemplary embodiments, the AC motor used to control the hoist speed may not be capable of stopping a lowering movement of the dipper  140  if the dipper  140  is moving at a high hoist speed depending on the load in the dipper  140 . 
         [0033]    In exemplary embodiments, the processor  302  monitors the input signals received from the one or more sensors  304  and responsively calculates a load in the dipper. In exemplary embodiments, the processor  302  limits the maximum lowering hoist speed as a function of the load in the dipper. For example, as the load in the dipper increases the maximum lowering hoist speed allowed by the processor  302  decreases. In exemplary embodiments, by limiting the maximum lowering hoist speed based on the load in the dipper the processor  302  ensures that the control system  300  is capable of stopping the movement of the dipper  140 , which will help prevent damage to the electric rope shovel machine. 
         [0034]    In exemplary embodiments, the control system  300  of the electric rope shovel machine is configured to prevent the excavating machine from stalling while the excavating machine is excavating. The electric rope shovel machine may stall during operation for a variety of reasons. One of the most common conditions that can cause a stall is if the operator places the dipper too deep into the bank. In other words, if the operator attempts to excavate too much material in a single operation with the dipper. In general, preventing the electric rope shovel machine from stalling while the electric rope shovel machine is actively digging will decrease the cycle time of the electric rope shovel machine and thereby increasing the efficiency of the electric rope shovel machine. 
         [0035]    In exemplary embodiments, the processor  302  monitors the input signals received from the one or more sensors  304  and responsively determines if the electric rope shovel machine is about to stall. In exemplary embodiments, the one or more input signals may include, but are not limited to, a voltage level of one or more AC motor of the electric rope shovel machine, a torque on the handle of the electric rope shovel machine, a tension in the hoist cable of the electric rope shovel machine, or the like. In exemplary embodiments, the processor  302  of the control system  300  continuously calculates a percentage chance that the electric rope shovel machine will stall based on the input signals received from the one or more sensors  304 . The processor  302  includes a stall threshold value that is compared to the calculated percentage and when the calculated percentage exceeds the stall threshold value the processor may set a flag indicating that a stall of the electric rope shovel machine is likely. 
         [0036]    In exemplary embodiments, based on the processor  302  setting a flag indicating that a stall of the electric rope shovel machine is likely, the control system  302  may make automatic adjustments to the operation of the electric rope shovel machine and may also provide a stall condition over-ride alert to an operator of the electric rope shovel machine. In one embodiment, the automatic adjustment to the operation of the electric rope shovel machine includes issuing a command to the AC motor controlling the handle to retract by a given distance. By retracting the handle, the amount of material that the dipper is removing from the bank is decreased and the chances of a stall occurring can be reduced. 
         [0037]    In exemplary embodiments, the control system  300  monitors the operation of the electric rope shovel machine and makes automatic adjustments to the operation of the electric rope shovel machine when the likelihood that a stall may occur exceeds a threshold level. Accordingly, the control system  300  reduces the likelihood that the electric rope shovel machine will experience a stall during operation and thereby increases the efficiency of the electric rope shovel machine. 
         [0038]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof. 
         [0039]    The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. 
         [0040]    The components and materials described hereinafter as making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components and materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of embodiments of the present invention. While embodiments of the present invention have been disclosed in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention and its equivalents, as set forth in the following claims.