Patent Publication Number: US-11021851-B2

Title: System and method for vibration monitoring of a mining machine

Description:
RELATED APPLICATIONS 
     The present application claims priority to U.S. patent application Ser. No. 13/743,894, filed Jan. 17, 2013, which claims priority to U.S. Provisional Application 61/587,890, filed Jan. 18, 2012, and U.S. Provisional Application 61/594,234, filed Feb. 2, 2012, the entire contents of which are hereby incorporated 
    
    
     BACKGROUND 
     The application relates to vibration monitoring for electric mining shovels. Two conventional types of vibration monitoring and analysis on mining machines include manual testing and primitive operational monitoring. Manual testing involved placing mining machines off-line and interrupting regular mining operations. Then, personnel would secure one or two vibration sensors on or near one or more moving components of the to-be-analyzed mining machine. The personnel would then instruct the operator of the mining machine to operate the mining machine in a particular way in order to capture vibration data. Thereafter, the captured data would be analyzed for diagnostic purposes. Manual testing was a labor intensive activity that required a high level of expertise for placement of vibration data sensors, vibration data collection, and vibration data analysis. Additionally, manual testing required interruption of mining operations for several hours. Primitive operational monitoring involved installing a vibration monitor for capture of vibration data during operation of the mining machine. The capture of vibration data was initiated based on two factors, motor speed and motor rotation direction. The capture of vibration data was not based on the shovel&#39;s operating cycle, but rather simply motor speed and rotational direction. This technique resulted not only in inefficient and inconsistent data capture, but collected vibration data that was difficult to analyze. 
     SUMMARY 
     Vibration monitoring enables monitoring of the overall bearing and shaft health of an electric mining shovel. 
     One embodiment provides a mining machine having a control system for operating the mining machine. The control system includes a vibration monitor. The mining machine further includes a sensor and a vibration control system. The sensor senses vibration of a component of the mining machine. The vibration control system determines when the mining machine is moving in a proper cycle, triggers acquisition of vibration sensor data from the sensor in response to determining that the mining machine is moving in the proper cycle, and outputs the vibration sensor data. 
     Another embodiment provides a method for monitoring mining equipment. The method including monitoring operation of a mining machine, and determining that a component of the mining machine is moving in a proper cycle. The method further including triggering, by a processor, the acquisition of vibration data of the mining machine in response to determining that the component of the mining machine is moving in the proper cycle, and outputting the vibration data. 
     Another embodiment provides a mining machine having a control system for operating the mining machine. The control system including a vibration monitor. The mining machine including a user-interface, a sensor, and a processor. The user-interface provides instructions to operate a component of the mining machine in a predetermined pattern. The sensor senses vibration of the component of the mining machine while the component operates in the predetermined pattern, the sensor outputting vibration sensor data. The processor receives the vibration sensor data from the sensor, processes the vibration sensor data, and outputs the processed vibration data. 
     Yet another embodiment provides mining machine having a control system for operating the mining machine. The mining machine includes a user-interface, a sensor, and a processor. The user-interface provides instructions to operate the mining machine in a predetermined pattern. The sensor senses a parameter of the mining machine while the mining machine operates in the predetermined pattern, and outputs sensor data representing the sensed parameter. The processor receives the sensor data from the sensor, processes the sensor data, and outputs the processed sensor data. 
     In some embodiments, the application includes a mining machine including a simulated tachometer and a vibration monitoring module. The simulated tachometer may include a voltage monitor, or a voltage monitor and a voltage-to-pulse converter, which are used to determine a speed of a component of the mining machine to generate sensed speed, which is outputted to the vibration module. The vibration module senses vibrations of the component of the mining machine, based on the sensed speed, and generates vibration data. The vibration module then processes the vibration data to generate a spectral waveform. The processing may include a Fourier transform and may be based in part on the sensed speed to adjust for variations in the speed of the component during collection of the vibration data. The component may be one of a hoist motor, crowd motor, swing motor, hoist gearbox, crowd gearbox, and swing gearbox. 
     Other aspects of the application will become apparent by consideration of the detailed description and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an electric mining shovel. 
         FIG. 2  illustrates a block diagram of a control system of the mining shovel of  FIG. 1 . 
         FIG. 3  illustrates a block diagram of a vibration data collection system of the mining shovel. 
         FIG. 4  illustrates a vibration spectrum analysis. 
         FIGS. 5 a -5 d    illustrate a user-interface of the control system. 
         FIG. 6  illustrates a process of collecting vibration data. 
         FIG. 7  illustrates a simulated tachometer of the mining shovel. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the application are explained in detail, it is to be understood that the application 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 application 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 is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “mounted,” “connected” and “coupled” are used broadly and encompass both direct and indirect mounting, connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and can include electrical connections or couplings, whether direct or indirect. Also, electronic communications and notifications may be performed using any known means including direct connections, wireless connections, etc. 
     It should also be noted that a plurality of hardware and software based devices, as well as a plurality of different structural components may be used to implement the application. In addition, it should be understood that embodiments of the application 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 application may be implemented in software (e.g., stored on non-transitory computer-readable medium) executable by one or more processors. 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 application. Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify embodiments of the application and that other alternative mechanical configurations are possible. For example, “controllers” described in the specification can include standard processing components, such as one or more processors, one or more computer-readable medium modules, one or more input/output interfaces, and various connections (e.g., a system bus) connecting the components. 
       FIG. 1  illustrates an electric mining shovel  100 . The embodiment shown in  FIG. 1  illustrates the electric mining shovel  100  as a rope shovel, however in other embodiments the electric mining shovel  100  can be a different type of mining machine, for example, a hybrid mining shovel, a dragline excavator, etc. The mining shovel  100  includes tracks  105  for propelling the rope shovel  100  forward and backward, and for turning the rope shovel  100  (i.e., by varying the speed and/or direction of the left and right tracks relative to each other). The tracks  105  support a base  110  including a cab  115 . The base  110  is able to swing or swivel about a swing axis  125 , for instance, to move from a digging location to a dumping location. Movement of the tracks  105  is not necessary for the swing motion. The rope shovel further includes a dipper shaft  130  supporting a pivotable dipper handle  135  (handle  135 ) and dipper  140 . The dipper  140  includes a door  145  for dumping contents from within the dipper  140  into a dump location, such as a hopper or dump-truck. 
     The rope shovel  100  also includes taut suspension cables  150  coupled between the base  110  and dipper shaft  130  for supporting the dipper shaft  130 ; a hoist cable  155  attached to a winch (not shown) within the base  110  for winding the cable  155  to raise and lower the dipper  140 ; and a dipper door cable  160  attached to another winch (not shown) for opening the door  145  of the dipper  140 . In some instances, the rope shovel  100  is a P&amp;H® 4100 series shovel produced by P&amp;H Mining Equipment Inc., although the electric mining shovel  100  can be another type or model of electric mining equipment. 
     When the tracks  105  of the mining shovel  100  are static, the dipper  140  is operable to move based on three control actions, hoist, crowd, and swing. The hoist control raises and lowers the dipper  140  by winding and unwinding hoist cable  155 . The crowd control extends and retracts the position of the handle  135  and dipper  140 . In one embodiment, the handle  135  and dipper  140  are crowded by using a rack and pinion system. In another embodiment, the handle  135  and dipper  140  are crowded using a hydraulic drive system. The swing control swivels the handle  135  relative to the swing axis  125 . Before dumping its contents, the dipper  140  is maneuvered to the appropriate hoist, crowd, and swing positions to 1) ensure the contents do not miss the dump location; 2) the door  145  does not hit the dump location when released; and 3) the dipper  140  is not too high such that the released contents would damage the dump location. 
     As shown in  FIG. 2 , the mining shovel  100  includes a control system  200 . The control system  200  includes a controller  205 , operator controls  210 , dipper controls  215 , sensors  220 , a user-interface  225 , and other input/outputs  230 . The controller  205  includes a processor  235  and memory  240 . The memory  240  stores instructions executable by the processor  235  and various inputs/outputs for, e.g., allowing communication between the controller  205  and the operator or between the controller  205  and sensors  220 . In some instances, the controller  205  includes one or more of a microprocessor, digital signal processor (DSP), field programmable gate array (FPGA), application specific integrated circuit (ASIC), or the like. 
     The controller  205  receives input from the operator controls  210 . The operator controls  210  include a crowd control  245 , a swing control  250 , a hoist control  255 , and a door control  260 . The crowd control  245 , swing control  250 , hoist control  255 , and door control  260  include, for instance, operator controlled input devices such as joysticks, levers, foot pedals, and other actuators. The operator controls  210  receive operator input via the input devices and output digital motion commands to the controller  205 . The motion commands include, for example, hoist up, hoist down, crowd extend, crowd retract, swing clockwise, swing counterclockwise, dipper door release, left track forward, left track reverse, right track forward, and right track reverse. 
     Upon receiving a motion command, the controller  205  generally controls dipper controls  215  as commanded by the operator. The dipper controls  215  include one or more crowd motors  265 , one or more swing motors  270 , and one or more hoist motors  275 . For instance, if the operator indicates via swing control  250  to rotate the handle  135  counterclockwise, the controller  305  will generally control the swing motor  270  to rotate the handle  135  counterclockwise. However, in some embodiments of the application the controller  205  is operable to limit the operator motion commands and generate motion commands independent of the operator input. 
     The controller  205  is also in communication with a number of sensors  220  to monitor the location and status of the dipper  140 . For example, the controller  205  is in communication with one or more crowd sensors  280 , one or more swing sensors  285 , and one or more hoist sensors  290 . The crowd sensors  280  indicate to the controller  205  the level of extension or retraction of the dipper  140 . The swing sensors  285  indicate to the controller  205  the swing angle of the handle  135 . The hoist sensors  290  indicate to the controller  205  the height of the dipper  140  based on the hoist cable  155  position. In other embodiments there are door latch sensors which, among other things, indicate whether the dipper door  145  is open or closed and measure weight of a load contained in the dipper  140   
     The user-interface  225 , such as an operator user-interface, provides information to the operator about the status of the mining shovel  100  and other systems communicating with the mining shovel  100 . The user-interface  225  includes one or more of the following: a display (e.g. a liquid crystal display (LCD)); one or more light emitting diodes (LEDs) or other illumination devices; a heads-up display (e.g., projected on a window of the cab  115 ); speakers for audible feedback (e.g., beeps, spoken messages, etc.); tactile feedback devices such as vibration devices that cause vibration of the operator&#39;s seat or operator controls  210 ; or another feedback device. 
       FIG. 3  illustrates a block diagram of a vibration data collection system  300  of the mining shovel  100 . The vibration data collection system  300  includes one or more accelerometer sensors  305 , one or more tachometers  307 , a vibration spectral analysis processor  310 , and a server  315 . The data collection system  300  is further electrically coupled to the controller  205 . 
     The accelerometer sensors  305  collect vibration data of the mining shovel  100  while the mining shovel  100  is in operation. The accelerometer sensors  305  measure vibrations of a structure. The force caused by vibrations causes a force onto the piezoelectric material within the accelerometer sensors  305 . The piezoelectric material produces an electric charge which is proportional to the force exerted upon it. The accelerometer sensors  305  may be radial accelerometer sensors or axial accelerometer sensors. The radial accelerometer sensors measure the acceleration on bearings of the mining shovel  100 . The axial accelerometer sensors measure the acceleration on shafts of the mining shovel  100 . The accelerometer sensors  305  are located at various locations on the mining shovel  100  including, among other locations, the one or more crowd motors  265 , the one or more swing motors  270 , the one or more hoist motors  275 , a hoist gearbox, a crowd gearbox, and a swing gearbox. 
     The tachometers  307  measure the rotational speed of the various motors of the mining shovel  100 . Each tachometer  307  can either be a physical tachometer or a simulated tachometer. A physical tachometer is an instrument that physically measures the rotational speed of a motor for example, using a optical or a magnetic sensor. Simulated tachometers are described in more detail below. 
     The vibration spectral analysis processor  310  processes vibration data from the accelerometer sensors  305  and outputs processed vibration data. In some embodiments the vibration spectral analysis processor  310  outputs the raw vibration data along with the processed vibration data. The vibration spectral analysis processor  310  includes a processor and memory. The processor executes instructions stored on the memory for analyzing and processing the received data from the accelerometer sensors  305 . In some instances the vibration spectral analysis processor  310  is a microprocessor, digital signal processor (DSP), field programmable gate array (FPGA), application specific integrated circuit (ASIC), or the like. In some embodiments, the vibration spectral analysis processor  310  processes the vibration data by creating a sound file of the vibration data. The vibration spectral analysis processor  310  then performs a Fourier transform on the created sound file to create a vibration spectrum. In other embodiments, other spectral analysis algorithms are applied to create different variations of the spectrum or analyze the data in another way. 
       FIG. 4  illustrates an exemplary vibration spectrum  320  created by the vibration spectral analysis processor  310 . A single vibration spectrum  320  corresponds to a part of the mining shovel  100  being monitored, such as a cooling fan, a gearbox, a transmission, or a motor (e.g., a hoist motor  275 ). Therefore, the vibration spectral analysis processor  310  creates multiple vibration spectrums  320  for each monitored part of the mining shovel  100 . A spectrum  320  includes several peaks  325 . Peaks  325  of a vibration spectrum  320  with an abnormally high amplitude indicate possible mechanical failure or future failure on a corresponding part of the mining shovel  100  (e.g., an exhaust fan, or one of the hoist motors  275 ). Vibration data may be obtained and processed periodically (e.g., on a weekly basis) to generate multiple spectrums  320  for each monitored part of the mining shovel  100 . A failure or impending failure may also be identified when a peak  325  for a particular frequency is shown to be increasing over time (e.g., over a few periodically created spectrums  320 ). 
     The server  315  is used to communicate the processed and/or raw vibration data, including the one or more vibration spectrums  320 , from the vibration spectral analysis processor  310  to a central location for further analysis. The server  315  may be in communication with the vibration spectrum analysis processor  310  via a local area network, a wide area network, a wireless network, the Internet, or the like. 
     In some embodiments, to collect valid vibration measurements, the vibration data collection system  300  obtains vibration data while movement of a component of the mining shovel  100  being tested is at a constant speed (i.e., movement of the dipper such as by swinging, crowding, hoisting, etc. at a constant speed) that is within a predefined speed range. In some embodiments, the speed is determined to be constant while the speed is varying by 50 RPM, 100 RPM, 300 RPM, or up to 600 RPM. When the speed varies, an algorithm may be used to account for the variations in speed. In some embodiments one to three seconds of vibration data is captured during movement at a constant speed, within the range, for accurate vibration analysis. In some embodiments, the speed of the component of the mining shovel  100  does not need to be within a predefined speed range. Constant speed can be maintained or identified during operation by a variety of methods explained in detail below. 
     Stage Testing 
     Stage testing is one embodiment of vibration data collection. Stage testing includes the mining shovel  100  moving in various predetermined patterns while the vibration data is collected by the data collection system  300 . By moving in predetermined patterns, vibration data can be captured at known points when the mining shovel  100  is operating at a constant speed. The predetermined patterns include, but are not limited to: hoisting the dipper  140  up and down; crowding the dipper  140  in and out; and swinging the handle  135  left and right. For example, when hoisting the dipper  140  up, the dipper  140  will move at a constant speed, within the predefined speed range, for approximately one to three seconds. Once the dipper  140  has been hoisted all the way up, the dipper  140  is stopped at the top and hoisted down. When the dipper  140  is hoisted down, the dipper  140  will move at a constant speed, within the range, for approximately one to three seconds until the dipper  140  is hoisted all the way down. This is repeated until enough vibration data is collected. In some instances, such as when hoisting the dipper  140  up and down, the predefined speed range is 1000 RPM to 1500 RPM. The predefined speed range may be different for other components or other predetermined patterns. 
       FIGS. 5 a -5 d    illustrate the stage testing operator instructions as they are displayed on the user-interface  225 , such as the operator user-interface, in one embodiment. Although discussed as being displayed on the user-interface  225 , in other embodiments, the stage testing instructions are displayed and/or generated audibly on a separate user-interface. 
     As shown in  FIG. 5 a   , the operator begins stage testing operations by selecting to begin a specific stage test using the user-interface  225 . For example, the operator uses the user-interface  225  to select hoist stage testing  330 , crowd stage testing  335 , swing stage testing  340 , or other various stage tests. 
     As shown in  FIG. 5 b   , once the operator has selected the specific stage test, the user-interface  225  informs the operator of the steps necessary to begin the testing. For example, as shown in  FIG. 5 b   , the user-interface  225  informs the operator to begin the test by instructing the operator to “Crowd dipper to full extension and then quickly move the hoist up and down.” 
     As shown in  FIG. 5 c   , once the operator begins the test, the user-interface  225  will continue to give operating instructions such as “Continue hoisting up and down.” The user-interface  225  further includes a progress bar  342  and a speedometer  345 . The progress bar  342  informs the operator of his progress during the stage testing. In other embodiments visual or audio progress indicators, other than a progress bar, are used to indicate the operator&#39;s progress during stage testing. The speedometer  345  informs the operator of the speed of the moving component of the mining shovel  100 . The speedometer  345  includes a target range  350  that indicates to the operator the predefined speed range that the moving component of the mining shovel  100  must be moving at for data to be captured. In some situations, in which the speed of a moving component does not need to be within a predefined speed range, the speedometer  345  is omitted from the user-interface  225 . As shown in  FIG. 5 d   , once the stage testing is complete the user-interface  225  instructs the operator to “Stop hoisting.” 
     As the mining machine  100  is operated during the various stage tests, the vibration data is obtained by the accelerometer sensors  305  and stored in a memory (e.g., of the accelerometer sensors  305  or the vibration spectral analysis processor  310 ). The recorded data is then processed by the vibration spectral analysis processor  310  to generate one or more spectrums  320  corresponding to various components of the mining shovel  100  (processed vibration data). The processed data can then be sent to an off-site location (e.g, server  315 ) for further analysis or to be displayed locally, such as on the user interface  225 . Additionally, the vibration spectral analysis processor  310 , server  315 , controller  205 , or another device may analyze the processed data to determine whether a failure has occurred or is impending on a component of the mining shovel  100 . In other words, the peaks  325  of spectrums are analyzed to determine whether they exceed a predetermined threshold or have increased over time at an excessive rate. The predetermined thresholds and rates may be specific to particular components as well. Accordingly, a peak  325  of one spectrum  320  corresponding to one component may be acceptable, but a similar peak  325  of another spectrum  320  corresponding to another component may be at a level that would indicate an issue. 
     Vibration Data Collection During Operation of Mining Shovel 
     Another method for collecting vibration data includes collecting the vibration data while the mining shovel  100  is in normal operation, rather than during stage testing. During normal operation, the mining shovel  100  operates in specific cycles, such as digging, swinging towards the dump location, and tucking. These cycles have specific speeds and torques associated with them. During portions of various cycles of the mining shovel  100  operation, the mining shovel  100  will have a constant speed, within the predefined range, and a constant torque, within a predefined range. Torque that remains positive or remains negative (i.e., does not cross the zero-torque threshold) during a particular time period is considered constant during that time period. The control system  200  uses an algorithm to identify the cycle that the mining shovel  100  is performing. In one embodiment, the algorithm uses speed, torque, and position to identify the cycle and trigger data collection. In another embodiment, the algorithm uses the rate of speed increase or decrease to trigger data collection. In another embodiment, the algorithm only uses speed and position to trigger data collection. 
       FIG. 6  illustrates a process  400  for collecting vibration data during operation of the mining shovel. Process  400  begins by monitoring the operation of the mining shovel  100  (Step  405 ). The data collection system  300  determines if the mining shovel  100  is in a proper cycle where the speed will remain constant for one to three seconds (Step  410 ). If the mining shovel  100  is not in a proper cycle, the data collection system  300  reverts back to step  405 . If the mining shovel  100  is in a proper cycle, the data collection system  300  determines if a component of the mining shovel  100  is at a constant speed, within the predefined speed range (Step  415 ). If the component of the mining shovel  100  is not at a constant speed and within the predefined speed range, the data collection system  300  reverts back to step  405 . If the component of the mining shovel  100  is at a constant speed, the data collection system  300  determines if the torque is constant and within the predefined torque range (Step  420 ). If the torque is not constant and within the predefined torque range, the data collection system  300  reverts back to step  405 . If the torque is constant and within the predefined torque range, the data collection system  300  begins collecting vibration data (Step  425 ). The data collection system  300  next determines if a sufficient amount of vibration data has been collected (Step  430 ). If a sufficient amount of vibration data has not been collected, the data collection system  300  reverts back to step  405 . Vibration data may be collected over several cycles. If a sufficient amount of vibration data has been collected, the vibration data is processed by the vibration spectral analysis processor  310  (Step  435 ). Next, the data collection system  300  or a technician determines if the processed vibration data indicates a mechanical issue (Step  440 ). If there is not an issue, the data collection system  300  reverts back to step  405 . If there is an issue, the data collection system  300  generates an alarm (Step  445 ). Once the vibration data is processed, the processed vibration data can be sent to an off-site location, such as the server  315 , for further analysis. In some embodiments, step  420  is bypassed in the process  400 , such that data capture is not triggered based on torque. 
     Simulated Tachometer 
     As discussed above, for the data collection system  300  to collect valid vibration measurements, the speed of the components of the mining shovel  100  being tested should remain relatively constant and within the predefined speed range. Thus, the tachometers  307  may be used to monitor the speed of components of the mining machine  100 . In some embodiments, such as a mining shovel  100  including direct-current motors, the mining shovel  100  uses simulated tachometers, rather than physical tachometers, as the tachometers  307 . 
     As shown in  FIG. 7 , a simulated tachometer  450  is used to determine speed. The simulated tachometer  450  includes a current monitor  455 , a voltage-to-pulse converter  460 , and a simulated tachometer analysis processor  465 . The simulated tachometer  450  can then be electrically coupled to the vibration data collection system  300 . 
     The voltage monitor  455  monitors the motor voltage of the mining shovel  100 . This monitored voltage is proportional to the speed of the motor. In some embodiments, the motor voltage of the mining shovel  100  is monitored by the control system  200 , and a separate voltage monitor  455  is unnecessary. The monitored voltage is outputted to the tachometer analysis processor  460 , which then outputs a voltage analog signal. In some embodiment, the tachometer analysis processor  460  outputs the voltage analog signal to a voltage-to-pulse converter  460 . The voltage-to-pulse converter  465  converts the voltage analog signal (e.g., 24 volts) to a frequency (e.g., 1000 Hz). The frequency, which is representative of the speed of the motor of the mining machine  100 , is then outputted to the vibration data collection system  300 , the user-interface  225 , or both. In some embodiments, the voltage analog signal is outputted directly to the vibration data collection system  300 , the user-interface  225 , or both, and a voltage-to-pulse converter  465  is unnecessary. In some embodiments, the simulated tachometer  450  uses the motor current in conjunction with the motor voltage to determine a speed of the motor of the mining machine  100 . 
     Thus, the application provides, among other things, a method and system for vibration testing of an electric mining shovel. Various features and advantages of the application are set forth in the following claims.