Patent Publication Number: US-10783721-B2

Title: Monitoring and diagnostics system for a machine with rotating components

Description:
TECHNICAL FIELD 
     This disclosure relates generally to machines with rotating components and, more particularly, to a system and method for monitoring and diagnosing failures based upon vibrations of the rotating components. 
     BACKGROUND 
     Rotating machinery is used in many applications. For example, machines such as mobile machines, e.g., on and off road vehicles, construction machines, earth working machines, and the like, employ principles of rotation to function. Powertrains including engines, motors, drive trains, ground engaging components such as wheels or tracks, and the like rotate to enable the machines to perform work tasks. 
     The efficiency and life expectancy of rotating machinery may be analyzed through an analysis of vibrations present in the machine components. In particular, the analysis of raw or high frequency vibrations may be particularly useful in determining faults that are occurring or that may occur in the future. In some instances, the vibration analysis may permit an estimation of the future life of components. 
     U.S. Patent Publication No. 2013/0211737 discloses a heath and usage monitoring system that includes at least one intelligent sensor, a central control module, and a communications network. The intelligent sensor comprises a signal processor, software, a vibration sensor, and a transceiver. The vibration sensor is mounted near a moving component and monitors operation of the moving component. 
     The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims. 
     SUMMARY 
     In one aspect, a monitoring and diagnostics system for a machine having a plurality of rotating components includes a powertrain with a plurality of rotating components and a vibration sensor. The vibration sensor include a vibration sensor element and a sensor controller. The vibration sensor is disposed adjacent one of the plurality of rotating components. The vibration sensor element is configured to generate raw vibration data indicative of vibrations of the vibration sensor element. The sensor controller is configured to access a vibration threshold, access a time threshold, receive the raw vibration data from the vibration sensor element, generate condition indicators based upon the raw vibration data, and compare the condition indicators to the vibration threshold. If the condition indicators exceed the vibration threshold for a time exceeding the time threshold, transmit a predetermined amount of raw vibration data to a remote system remote from the machine. 
     In another aspect, a method of monitoring and diagnosing a machine having a plurality of rotating components includes accessing a vibration threshold, accessing a time threshold, and receiving raw vibration data from a vibration sensor element of a vibration sensor, with the vibration sensor element being disposed adjacent one of the plurality of rotating components. The method further includes utilizing a sensor controller of the vibration sensor to generate condition indicators based upon the raw vibration data, utilizing a sensor controller of the vibration sensor to compare the condition indicators to the vibration threshold, and if the raw vibration data exceed the vibration threshold for a time exceeding the time threshold, transmitting a predetermined amount of raw vibration data to a remote system remote from the machine. 
     In still another aspect, a machine includes a powertrain having a prime mover, a transmission operatively connected to the prime mover, and ground engaging drive mechanisms operatively connected to the transmission, with the powertrain further including a plurality of rotating components. A vibration sensor includes a vibration sensor element and a sensor controller. The vibration sensor is disposed adjacent one of the plurality of rotating components. The vibration sensor element is configured to generate raw vibration data indicative of vibrations of the vibration sensor element. The sensor controller is configured to access a vibration threshold, access a time threshold, receive the raw vibration data from the vibration sensor element, generate condition indicators based upon the raw vibration data, and compare the condition indicators to the vibration threshold. If the condition indicators exceed the vibration threshold for a time exceeding the time threshold, transmit a predetermined amount of raw vibration data to a remote system remote from the machine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts a diagrammatic illustration of the haul truck for use with a monitoring and diagnostics system in accordance with the disclosure; 
         FIG. 2  depicts a block diagram of a powertrain and sensors of the haul truck of  FIG. 1 ; 
         FIG. 3  depicts a block diagram of a smart sensor for use with the monitoring and diagnostics system; 
         FIG. 4  depicts a block diagram of the monitoring and diagnostics system for use with the haul truck of  FIG. 1 ; and 
         FIG. 5  depicts a flowchart illustrating a process for operating the monitoring and diagnostics system. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  depicts a diagrammatic illustration of an exemplary machine configured as a haul truck  10  for hauling or transporting material. The haul truck depiction is merely for illustrative purposes in that the systems depicted herein may be used with any type of machine having rotating components. 
     The haul truck  10  includes a frame  12  and a payload container  13  that may be pivotably mounted on frame. Haul truck  10  may include a cab  14  for an operator to physically occupy and provide input to control the machine. 
     Referring to  FIG. 2 , haul truck  10  may include a powertrain  15  that includes a prime mover such as an engine  16  that is operatively connected to and may drive a transmission  17 . Transmission  17  may be operatively connected to and drive a drop box or gearbox  18 . In some instances, the transmission  17  and the gearbox  18  may be a single unit. A rear drive shaft  20  operatively connects the gearbox  18  to a rear final drive  21  that is operatively connected to and may drive the ground engaging drive mechanisms configured as rear wheels  22 . A front drive shaft  23  operatively connects the gearbox  18  to a front final drive  24  that is operatively connected to and may drive the ground engaging drive mechanisms configured as front wheels  25 . 
     The haul truck  10  may use any type of propulsion and drivetrain mechanisms including hydrostatic, electric, or a mechanical drive. Regardless of the type or configuration, the powertrain  15  includes a plurality of rotating components or elements. For example, the prime mover, when configured as an engine  16 , may include a crankshaft (not shown), cam shafts (not shown), sprockets (not shown) and other rotating components or elements. The transmission  17 , gearbox  18 , rear final drive  21 , and front final drive  24  may also each include rotating shafts (not shown) and/or rotating gears (not shown). 
     Haul truck  10  may be controlled by a control system  30  as shown generally by an arrow in  FIG. 1  indicating association with the machine. The control system  30  may include an electronic control module or controller  31  and a plurality of sensors. The controller  31  may control the operation of various aspects of the haul truck  10  including the powertrain  15  and other systems. 
     The controller  31  may be an electronic controller that operates in a logical fashion to perform operations, execute control algorithms, store, retrieve, and access data and other desired operations. The controller  31  may include or access memory, secondary storage devices, processors, and any other components for running an application. The memory and secondary storage devices may be in the form of read-only memory (ROM) or random access memory (RAM) or integrated circuitry that is accessible by the controller. Various other circuits may be associated with the controller  31  such as power supply circuitry, signal conditioning circuitry, driver circuitry, and other types of circuitry. 
     The controller  31  may be a single controller or may include more than one controller disposed to control various functions and/or features of the haul truck  10 . The term “controller” is meant to be used in its broadest sense to include one or more controllers and/or microprocessors that may be associated with the haul truck  10  and that may cooperate in controlling various functions and operations of the machine. The functionality of the controller  31  may be implemented in hardware and/or software without regard to the functionality. The controller  31  may rely on one or more data maps relating to the operating conditions and the operating environment of the haul truck  10  and a work site that may be stored in the memory of or associated with the controller. Each of these data maps may include a collection of data in the form of tables, graphs, and/or equations. As depicted, the controller  31  is on-board the haul truck  10 . 
     The control system  30  may include a monitoring and diagnostics system as shown generally at  32  for diagnostic purposes and, in some instances, for predicting the remaining useful life machine components and systems. To do so, the monitoring and diagnostics system  32  may receive data from various sensors on and/or off the haul truck  10  and compare the data to the data maps of the controller  31  to identify failures or fault conditions. In one embodiment, the monitoring and diagnostics system  32  may be used to identify failures or fault conditions associated with the powertrain  15 . 
     The haul truck  10  may be equipped with a plurality of sensors that provide data indicative (directly or indirectly) of various operating parameters of elements of the powertrain  15  and/or the operating environment in which the powertrain is operating. The term “sensor” is meant to be used in its broadest sense to include one or more sensors and related components that may be associated with the powertrain  15  and that may cooperate to sense various functions, operations, and operating characteristics of the elements of the powertrain and/or aspects of the environment in which the powertrain is operating. 
     A plurality of speed sensors may be operatively associated with components of the powertrain  15 . In  FIG. 4 , the speed sensors are generically identified at  34 . Referring back to  FIG. 2 , an engine speed sensor generally indicated at  35  may be provided on or associated with the engine  16  to monitor the output speed of the engine. The engine speed sensor  35  may generate engine speed data indicative of the output speed of engine  16 . 
     A transmission speed sensor generally indicated at  36  may be provided on or associated with the transmission  17  to monitor the output speed of the transmission. The transmission speed sensor  36  may generate transmission speed data indicative of the output speed of transmission  17 . 
     In some instances, in addition or in the alternative to any other sensors, a gearbox speed sensor generally indicated at  37  may be provided on or associated with the gearbox  18  to monitor the output speed of the gearbox. The gearbox speed sensor  37  may generate gearbox speed data indicative of the output speed of gearbox  18 . 
     In some instances, in addition or in the alternative to any other sensors, a rear drive shaft speed sensor generally indicated at  38  may be provided on or associated with the rear drive shaft  20  to monitor the speed of the rear drive shaft and a front drive shaft speed sensor generally indicated at  40  may be provided on or associated with the front drive shaft  23  to monitor the speed of the front drive shaft. The drive shaft speed sensors  38 ,  40  may generate drive shaft speed data indicative of the speed of respective drive shafts  20 ,  23 . 
     In some instances, in addition or in the alternative to any other sensors, a rear final drive speed sensor generally indicated at  41  may be provided on or associated with the rear final drive  21  to monitor the speed of the rear final drive and a front final drive speed sensor generally indicated at  42  may be provided on or associated with the front final drive  24  to monitor the speed of the front final drive. The final drive speed sensors  41 ,  42  may generate final drive speed data indicative of the speed of respective final drives  21 ,  24 . 
     Other sensors may be associated with each of the engine  16 , transmission  17 , gearbox  18 , rear drive shaft  20 , rear final drive  21 , and front drive shaft  23 , and front final drive  24 . In one example, a fuel usage sensor  45  may be provided to sense the amount of fuel being used by the engine  16 . In another example, the engine  16  may include one or more pressure sensors  46  to sense the pressure of different systems associated with the engine (e.g., intake air pressure, exhaust gas pressure). In still another example, the engine  16  may include one or more temperature sensors to sense the temperature of different systems associated with the engine (e.g., intake air temperature, exhaust gas temperature). Other components of the powertrain  15  may also include temperature sensors, if desired. Still further, an ambient air temperature sensor indicated generally at  48  ( FIG. 1 ) may also be provided if desired. 
     The combination of the fuel usage sensor  45  and the engine speed sensor  35  may act as an equivalent of a torque sensor for generating torque signals indicative of an output torque from the engine  16 . Other manners of determining the output torque from the prime mover are contemplated. For example, other sensors may be used when using a non-combustion power source. 
     Each of the foregoing sensors may operate at a relatively low speed or sampling rate. In some embodiments, the sampling rate may be between 1 and 100 Hz (i.e., between 10 and 1000 ms). 
     The rotating components of the powertrain  15  may be subjected to and exhibit vibrations during the operation of the haul truck  10 . Monitoring and analysis of the vibrations of the rotating components may be used by the monitoring and diagnostics system  32  for diagnostic purposes and, in some instances, for predicting the remaining useful life of machine components and systems. 
     Accordingly, each of the components of the powertrain  15  may include one or more vibration sensors  50  ( FIG. 4 ) operatively associated therewith. The vibration sensors  50  may be mounted in any desired manner. In some instances, a vibration sensor  50  may be positioned or disposed on the component being monitored and in other instances may be near or adjacent the component being monitored. 
     As depicted in  FIG. 2 , one or more engine vibration sensors  51  may be operatively associated with the engine  16 , one or more transmission vibration sensors  52  may be operatively associated with the transmission  17 , one or more gearbox vibration sensors  53  may be operatively associated with the gearbox  18 , one or more rear drive shaft vibration sensors  54  may be operatively associated with the rear drive shaft  20 , one or more rear final drive vibration sensor  55  may be operatively associated with the rear final drive  21 , one or more front drive shaft vibration sensors  56  may be operatively associated with the front drive shaft  23 , and one or more front final drive vibration sensors  57  may be operatively associated with the front final drive  24 . 
     Each of the vibration sensors  50  may be provided on or associated with the components of the powertrain  15  to permit the sensors to monitor vibrations of the respective components of the powertrain. Although described with each component of the powertrain  15  having one or more vibration sensors  50 , the systems described herein may not require that each of components include at least one vibration sensor. 
     Referring to  FIG. 3 , each of the vibration sensors  50  may comprise a vibration sensor element  60  configured as an accelerometer that generates acceleration data or signals indicative of the acceleration of one or more components of the powertrain  15 . In one example, the vibration sensor element  60  may comprise a Piezoelectric accelerometer. The use of other types of vibration sensor elements and other types of accelerometers are contemplated. In some embodiments, the accelerometer may be a multi-axis accelerometer. In other embodiments, the accelerometer may be a single axis accelerometer. 
     In an embodiment, each vibration sensor  50  may be configured as a “smart sensor” including the vibration sensor element  60  for sensing and generating vibration data, a processor  61  (analog and/or digital) for controlling the operation of the vibration sensor, memory  62  for storing data (either raw or manipulated), and other components or circuitry  63  as desired to permit the vibration sensor to process, store, analyze, transform, and otherwise manipulate or control data as desired. As used herein, the sensor controller, generally depicted at  64 , refers to the processor  61  as well as the memory  62  and the other components or circuitry  63  to the extent necessary to carry out the desired functionality of the sensor controller. The processor  61  and the sensor controller  64  are each distinct from the controller  31 . In some instances, each vibration sensor  50  may be a single component such as with each element mounted or formed on a single circuit board, a circuit member, or within a housing. 
     In order to provide acceleration data that is useful to the monitoring and diagnostics system  32 , the vibration sensors  50  may be configured to be used with a relatively high frequency sampling rate. More specifically, if the sampling rate is too low, the vibration data may not provide enough differentiation between the acceleration data to permit the monitoring and diagnostics system  32  to operate as desired. In one example, the sampling rate may be at least 20 kHz. In another example, the sampling rate may be at least 10 kHz. In still another example, the sampling rate may be at least 5 kHz. As used herein, a sampling rate of at least 5 kHz means a sampling rate with a frequency of 5 kHz or more such as 5 kHz, 10 kHz, 20 kHz or other frequencies greater than 5 kHz. Other sampling rates are contemplated. As used herein, a sampling rate above 1 kHz may be considered high frequency. 
     The controller  31  may be configured to operate with sampling rates of between 0.1-100 Hz (i.e., 10 ms to 10 seconds). Accordingly, the controller  31  may receive and process data from the speed sensors  34 , the fuel usage sensor  45 , the pressure sensors  46 , and the temperature sensors  47 ,  48  without any loss in signal quality because those sensors have operating ranges within the sampling rate of the controller. However, since it is desirable for the vibration data from the vibration sensors  50  to have a higher sampling rate in order to capture the desired information, in many instances, the controller  31  may not be able to process the vibration data or the distinctions in the movement of the sensors may not be identified by the controller. Accordingly, the sensor controller  64  of the vibration sensor  50  may be configured to operate at a sufficiently high sampling rate or processing speed to permit the analysis and/or manipulation of the raw vibration data. As used herein, “raw vibration data” refers to vibration data sampled or gathered at a high frequency (i.e., above 1 kHz). 
     More specifically, the vibration sensors  50  may be configured to process or analyze the raw vibration data from the vibration sensor element  60  into lumped sum values that summarize the raw vibration data in some manner to extract some feature or features from the raw vibration data to permit subsequent analysis. Those features may be referred to as condition indicators. Examples of such condition indicators include overall energy (i.e., root mean square (“RMS”) average of the raw acceleration or vibration data), peak to peak values, kurtosis, crest factor (or other statistics base values), energy over a specified frequency (e.g., 1 kHz), energy over a specified frequency and some sidebands (e.g., 1 kHz plus bands of 100 Hz on each side of 1 kHz), energy over a specified frequency and some harmonics (e.g., 1 kHz plus a first harmonic of 2 kHz), enveloping energy at certain frequency bands, or any other processed parameters based on different purposes. 
     In some instances, the vibration sensor  50  may be configured to receive data from other sensors or systems and process the raw vibration data to generate the condition indicators based upon the data from the other sensors or systems. For example, a specified or predetermined frequency about which the analysis may be performed may be selected based upon the rotational speed of components within the powertrain  15  as well as the torque generated by the engine  16 . In another example, the type of analysis used to generate the condition indicators may be based upon the rotational speed of components within the powertrain  15  as well as the torque generated by the engine  16 . 
     The sensor controller  64  of each vibration sensor  50  may be configured to receive raw vibration data and process the data into a form that may be more readily usable by the controller  31 . To do so, the sensor controller  64  may repeatedly summarize a specified time period or length of time (e.g., 1 second) of the raw vibration data to generate a plurality of lumped sum values or condition indicators at a slower rate or frequency than the frequency of the raw vibration data. These condition indicators are thus generated at a slower update rate that is within the acceptable sampling rate or processing speed of the controller  41  as compared to the sampling rate of the vibration sensor element  60 , which is above the sampling rate of the controller. Thus, the vibration sensor  50  is able to transform the raw vibration data into a form that is usable by the controller  31 . The condition indicators may be provided as output in digital form from the vibration sensor  50 . As used herein, updating the condition indicators at a rate below 1 kHz may be considered low frequency. 
     If desired, the rate at which the condition indicators are updated or provided to the controller  31  from vibration sensors  50  may not be uniform. In an example, the update rate at which the condition indicators are generated and provided to controller  31  may be vary and may be dependent upon the rotational speed of components within the powertrain  15  and/or the torque generated by the engine  16 . 
       FIG. 4  depicts a block diagram of the monitoring and diagnostics system  32  for use with a machine such as haul truck  10 . In  FIG. 4 , the speed sensors are identified at  34  and may correspond to any of the engine speed sensor  35 , the transmission speed sensor  36 , the gearbox speed sensor  37 , the drive shaft speed sensors  38 ,  40 , and/or the final drive speed sensors  41 ,  42 . One or more of the components of the powertrain  15  may be operatively associated (as depicted by dashed line  65 ) with one or more speed sensors  34 . In  FIG. 4 , the vibration sensors are identified at  50  and may correspond to any of the engine vibration sensor  51 , the transmission vibration sensor  52 , the gearbox vibration sensor  53 , the drive shaft vibration sensors  53 ,  55 , and/or the final drive vibration sensors  54 ,  56 . One or more of the components of the powertrain  15  may be operatively associated (as depicted by dashed line  66 ) with one or more vibration sensors. Although two vibration sensors  50  are depicted in  FIG. 4 , any number of vibration sensors may be associated with the powertrain  15  and the monitoring and diagnostics system  32 . 
     Speed signals from the speed sensors  34  may be transmitted along a first communications link  67  and received by controller  31 . Speed signals from the speed sensors  34  may also be transmitted along second communications links  68  between the speed sensors and the vibration sensors  50 . The second communications links  68  may transmit or interconnect any combination of the speed sensors  34  and vibration sensors  50 . Speed signals from the speed sensors  34  may further be transmitted along a third communications link  69  to a storage system  33 . 
     Fuel sensor  45  may be operatively associated with the engine  16  as depicted by dashed line  79 . Fuel signals from the fuel sensor  45  may be transmitted to the controller  31  along fourth communications link  70  and to the storage system  33  along fifth communications link  71 . Torque signals indicative of the torque generated by the engine  16  may be transmitted to the vibration sensors  50  along sixth communications link  72 . 
     Condition indicators from each vibration sensor element  60  may be compared to one or more vibrations thresholds by the sensor controller  64  and if a threshold is exceeded, raw vibration data may be sent by the processor along a seventh communications link  73  to a remote system  100  such as a remote network or a system accessible through the “cloud” that is at a location remote from haul truck  10 . If desired, the remote system  100  may request additional raw vibration data from the vibration sensor  50  along an eighth communications link  74 . 
     The condition indicators generated by each vibration sensor  50  may be sent by the sensor controller  64  along a ninth communications link  75  to the storage system  33 . Data or signals may also be sent bi-directionally between the controller  31  and the vibration sensors  50  along sixth communications link  72 . As an example, condition indicators may be sent by the vibrations sensors  50  to the controller  31 . As another example, controller  31  may send instructions to the vibration sensors  50 , such as instructing the vibration sensor to send raw vibration data to remote system  100 . 
     The storage system  33  may be configured to send data to controller  31  along a tenth communications link  76 . Storage system  33  may be configured in any manner. In an embodiment, storage system  33  may be configured as CAN-compatible storage component or system and thus may connect to controller  31  along a CAN bus of haul truck  10 . In an embodiment, storage system  33  may have sufficient capacity to store data for months or years to permit subsequent analysis of the historical data associated with powertrain  15 . 
     An eleventh communications link  77  may be provided between the controller  31  and the remote system  100  to provide data from the other sensors to the remote system. This data may be used together with the raw vibration data at the remote system  100  for diagnostic or other purposes. 
     Each of the communications links  67 - 77  may be wired or wireless and may form a portion of a communications bus of the haul truck  10 . Each of the communications links may be mono-directional or be bi-directional, as desired. 
     The haul truck  10  and remote system  100  may each include a transceiver generally indicated at  78  to facilitate communications between the haul truck and the remote system. The transceiver  78  on-board haul truck  10  may communicate with the vibration sensor  50  directly or through controller  31  to facilitate communications to and from the haul truck to the remote system  100 . 
     INDUSTRIAL APPLICABILITY 
     The industrial applicability of the system described herein will be readily appreciated from the forgoing discussion. The monitoring and diagnostics system  32  may be used with machines that include rotating components that are subject to vibrations. The monitoring and diagnostics system  32  may determine whether rotating components are experiencing a fault condition based upon raw vibration data that is analyzed by vibration sensors  50  configured as smart sensors. The vibration sensors  50  may calculate condition indicators from the raw vibration data and compare the condition indicators to vibration thresholds. If the condition indicators exceed the thresholds, the vibration sensor  50  may send raw vibration data to a remote system  100 . 
       FIG. 5  depicts one example of the operation of the monitoring and diagnostics system  32 . At stage  80 , a plurality of thresholds may be stored. The thresholds may include one or more machine speed thresholds, one or more critical vibration thresholds, one or more warning vibration thresholds, one or more time thresholds, and a counter threshold. 
     In an embodiment, the machine speed threshold may correspond to a maximum change in speed of the haul truck  10  over a specified period of time. The machine speed threshold may be used to determine when the change in speed of the haul truck  10  is sufficiently low so as to permit the use of the monitoring and diagnostics system  32 . In an example, the haul truck  10  may be considered to be operating at a steady state condition if the speed of the machine does not vary by more than two percent over a ten second period. In an example, haul truck  10  may be considered to be operating at a slow speed change condition if the speed of the machine does not vary by more than 30 percent over a ten second period. 
     In some embodiments, different critical vibration thresholds may be used depending on whether the machine is operating at a steady-state condition or whether the machine is operating at a slow speed change condition. In some embodiments, different warning vibration thresholds may be used depending on whether the machine is operating at a steady-state condition or whether the machine is operating at a slow speed change condition. Whether the machine is operating at a steady state condition or a slow speed change condition may be determined from data from any desired speed sensor  34 . 
     A critical vibration threshold may be used to determine when the vibrations or energy measured by a vibration sensor  50  is sufficiently large so that a significant or critical issue may be occurring. Each vibration sensor  50  may be configured to operate with a plurality of critical vibration thresholds. In an example, a first critical vibration threshold may correspond to vibrations or an energy that exceeds a first threshold for a first critical time threshold or length of time. A second critical vibration threshold may correspond to vibrations or an energy that is less than a second, smaller vibration threshold but occur for a second critical time threshold or length of time that is greater than the first time threshold. 
     Further, different critical vibration thresholds may also be provided that correspond to different speeds from the speed sensors  34  and different torques from the torque sensor. In other words, the critical vibration thresholds being used at a particular time may be dependent upon the speed of a component of the drivetrain  15  and the torque generated by the engine  16 . 
     A warning vibration threshold may be used to determine when the vibrations or energy measured by a vibration sensor  50  is sufficiently large so that an issue may be occurring but it does not rise to the level of a critical issue. In order to minimize or reduce the possibility of false positive warnings, the monitoring and diagnostics system  32  may require that the warning vibration threshold be exceeded more than once during a specified time period before confirming that an issue is occurring. 
     As with the critical vibration thresholds, each vibration sensor  50  may be configured to operate with a plurality of warning vibration thresholds. In an example, a first warning vibration threshold may correspond to vibrations or energy that exceeds a first threshold for a first warning time threshold or length of time. A second warning vibration threshold may correspond to vibrations or energy that is less than a second, smaller threshold but for a second warning time threshold that is greater than the first warning time threshold. 
     As also with the critical vibration thresholds, different warning vibration thresholds may also be provided that correspond to different speeds from the speed sensors  34  and different torques from the torque sensor. In other words, the warning vibration thresholds being used at a particular time may be dependent upon the speed of a component of the drivetrain  15  and the torque generated by the engine  16 . 
     The haul truck  10  may be operated at stage  81 . Data from the speed sensors  34  may be received at stage  82 . More specifically, data from the speed sensors  34  may be received at the controller  31 , the storage system  33 , and at each of the vibration sensors  50 . In some instances, only data from certain speed sensors  34  will be received at certain of the vibration sensors  50 . In other words, the speed data from each speed sensor  34  may not need to be received at each vibration sensor  50 . 
     Torque signals indicative of the torque generated by the engine  16  may be received at stage  83 . In one embodiment, fuel usage signals may be received by the controller  31  from the fuel usage sensor  45 . The torque signals may be generated by the controller  31  based upon the engine speed signals and fuel usage signal and transmitted to the vibration sensors  50 . In another embodiment, torque data or signals may be sent directly to the vibration sensors  50  from a torque sensor. 
     Raw vibration data from each vibration sensor element  60  may be received by its sensor controller  64  at stage  84 . At stage  85 , the sensor controller  64  may analyze the raw vibration data and generate a summary in the form of lumped sum values or condition indicators. As an example, raw vibration data may be sampled at 20 kHz. The sensor controller  64  may summarize one second of data to generate a single data point or condition indicator. The vibration sensor  50  may continue this process to generate condition indicators at a rate of 1 Hz. Other rates of summarizing the raw vibration data are contemplated. The rate at which the raw vibration data may be sampled or summarized may be dependent upon the rotational speed of the component adjacent the relevant vibration sensor. 
     The condition indicators may be transmitted to and stored at the controller  31  and/or the storage system  33  at stage  86 . At stage  87 , the controller  31  may determine the speed of the haul truck  10 . To do so, the controller  31  may analyze speed data from any of the speed sensors  34 . If the haul truck  10  is not operating within a desired threshold (e.g., steady state or slow speed change) at stage  87 , the machine may continue to be operated and stages  81 - 87  repeated. 
     If the haul truck  10  is operating within a desired threshold (e.g., steady state or slow speed change) at stage  88 , the sensor controller  64  of each vibration sensor  50  may compare at stage  89  the condition indicators to the critical vibration thresholds for that vibration sensor. In doing so, the sensor controller  64  of each vibration sensor may utilize speed data (e.g., the speed) from any desired speed sensor as well as the torque signals and use the critical vibration threshold or thresholds corresponding to the speed data and/or torque signals. 
     If the condition indicators from a vibration sensor  50  exceed one or more critical vibration thresholds at stage  90  for a specified period of time, the sensor controller  64  of the vibration sensor may transmit at stage  91  a desired or predetermined amount of raw vibration data to the remote system  100 . The amount of raw vibration data sent from the vibration sensor  50  to the remote system  100  may be dependent upon the bandwidth and transmission capabilities associated with the monitoring and diagnostics system  32 . In an example, the sensor controller  64  may be configured to send approximately two seconds of raw vibration data to the remote system  100  via a wireless system generally indicated at  101  in  FIG. 4 . In other examples, other amounts of raw vibration data may be sent to the remote system  100 . If desired, data from other sensors may also be sent by controller  31  to the remote system  100 . 
     In addition or in the alternative, if the condition indicators from a vibration sensor  50  exceed one or more critical vibration thresholds at stage  90  for a specified period of time, a request may be generated to perform an oil sampling. The oil sampling may be performed manually or using sensors and may analyze properties of and debris in the oil and the condition of the filter. The analyzed oil properties may include the conductivity, permittivity, dielectric constant and any other desired property. The results of the oil sampling may be sent to the remote system  100 . 
     In some instances, communications between the haul truck  10  and the remote system  100  may not be possible which will prevent raw vibration and other data from being sent from the haul truck to the remote system. This may occur if some aspect of the communications link  77  between the haul truck  10  and the remote system  100  is not functioning properly or if the haul truck is in a remote location or a location in which communications services are insufficient or nonexistent. In such circumstance, the raw vibration data (together with any other data) may be stored within the storage system  33  until the necessary communication is possible. 
     If desired, the remote system  100  may transmit a request at stage  92  for additional raw vibration data to the vibration sensor  50 . In response, the sensor controller  64  may transmit an additional predetermined amount of raw vibration data to the remote system  100  based upon the request. At stage  93 , analysis of raw vibration data received from the vibration sensor  50  may be performed at the remote location as desired. The remote system  100  may include additional computing and diagnostics capabilities beyond those on-board the haul truck  10 . If desired, the haul truck  10  may continue to be operated and stages  81 - 96  repeated. In other instances, the operation of the machine may be terminated. 
     If the condition indicators from a vibration sensor  50  does not exceed one or more critical vibration thresholds at stage  90  for a specified period of time, the sensor controller  64  of the vibration sensor  50  may compare at stage  94  the condition indicators to the warning vibration thresholds. In doing so, the sensor controller  64  of each vibration sensor may utilize speed data (e.g., the speed) from any desired speed sensor as well as the torque signals and use the warning vibration threshold or thresholds corresponding to the speed data and/or the torque signals. 
     If the condition indicators from a vibration sensor  50  do not exceed one or more warning vibration thresholds at stage  95  for a specified period of time, the haul truck  10  may continue to be operated and stages  81 - 96  repeated. If the condition indicators from a vibration sensor  50  exceed one or more warning vibration thresholds at stage  95  for a specified period of time, the sensor controller  64  of the vibration sensor may utilize a counter to determine at stage  96  whether a counter threshold has been exceeded. 
     The counter may operate by tracking or counting the number of times that one or more warning vibration thresholds have been exceeded within a specified period of time (e.g., the reset threshold time period). In an example, the counter associated with a warning vibration threshold may be reset after a two hour time period if the warning vibration threshold has not been exceeded a second time. In another example, the counter associated with a warning vibration threshold may be reset after one hour of continuous operation if the warning vibration threshold has not been exceeded a second time. 
     If the condition indicators from a vibration sensor  50  exceed one or more warning vibration thresholds at stage  95  and the counter has not been exceeded at stage  96 , the haul truck  10  may continue to be operated and stages  81 - 96  repeated. If the condition indicators from a vibration sensor  50  exceed one or more warning vibration thresholds at stage  95  and the counter has been exceeded at stage  96 , stages  91 - 93  may be repeated. If desired, the haul truck  10  may continue to be operated and stages  81 - 96  repeated. In other instances, the operation of the machine may be terminated. 
     In an embodiment, if desired, the remote system  100  may transmit a request to the vibration sensor  50  for raw vibration data without the condition indicators exceeding either a critical vibration threshold or a warning vibration threshold. In response, the sensor controller  64  may transmit an additional predetermined amount of raw vibration data to the remote system  100  based upon the request. Analysis of raw vibration data received from the vibration sensor  50  may be performed at the remote location as desired. 
     It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated. 
     Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. 
     Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.