Patent Publication Number: US-2018030914-A1

Title: System for determining piston ring wear

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a system for determining piston damage and, more particularly, to a system for system for monitoring and determining piston ring wear and for determining an amount of damage to the piston ring based on the piston ring wear. 
     BACKGROUND 
     An internal combustion engine may include an engine block defining a plurality of cylinder bores, a crankshaft rotatably supported in the engine block, and pistons connected to the crankshaft and configured to reciprocate within the cylinder bores. Typically, each piston may include a skirt pivotally connected to the crankshaft, and a crown connected to a distal end of the skirt. A combustion bowl may be formed on an end face of the crown to receive injected fuel, and annular grooves may be formed in an outer surface of the crown to receive associated rings. A cooling passage may be annularly formed inside the crown, between the bowl and the cooling passage, to circulate engine oil that may cool the bowl. 
     The crown may include grooves and the grooves may receive piston rings. In this regard, a top piston ring (one of the piston rings) may seal combustion gases from a crankcase that houses the crankshaft. A portion of the top piston ring may include a coating that may help seal the combustion gases from the crankcase. Over a period of time, cylinder pressure (e.g., resulting from movement the piston) may act on the top piston ring and cause wear of the coating. As the coating wears, the top piston ring may wear. Wear of the top piston ring may reduce the seal and enable excessive blowby of combustion gases into the crankcase, thereby compromising oil quality. 
     U.S. Patent Application Publication No. 20150345421 (hereinafter the &#39;421 publication) is directed to a piston of an internal combustion engine. The piston may include a piston crown with annular grooves, a combustion chamber bowl, and a piston skirt with a pin bore to receive a pin. However, the &#39;421 publication does not disclose monitoring wear of a piston ring. 
     SUMMARY 
     In some embodiments, a control system, monitoring an amount of wear of a piston ring of a piston of an engine, may comprise a sensor configured to detect a cylinder pressure associated with the piston; a memory configured to store piston ring wear information; and an electronic control module. The electronic control module may be configured to: obtain, from the piston ring wear information stored in the memory, information identifying a previous amount of wear of the piston ring and information identifying an initial thickness of a coating of the piston ring; determine a piston ring wear rate based on the cylinder pressure; determine an amount of time between a current time and a time when the previous wear of the piston ring was calculated; calculate a current amount of wear of the piston ring based on the previous amount of wear of the piston ring, the amount of time, and the piston ring wear rate; calculate an amount of damage to the piston ring based on the current amount of wear of the piston ring and the initial thickness; and take a remedial action based on the amount of damage to the piston ring. 
     In some embodiments, a method, for monitoring an amount of wear of a piston ring of a piston of an engine, may comprise detecting, by a sensor, a cylinder pressure associated with the piston; obtaining, by an electronic control module and from piston ring wear information stored in a memory, information identifying a previous amount of wear of the piston ring and information identifying an initial thickness of a coating of the piston ring; determining, by the electronic control module, a piston ring wear rate based on the cylinder pressure; determining, by the electronic control module, an amount of time between a current time and a time when the previous wear of the piston ring was calculated; calculating, by the electronic control module, a current amount of wear of the piston ring based on the previous amount of wear of the piston ring, the amount of time, and the piston ring wear rate; calculating, by the electronic control module, an amount of damage to the piston ring based on the current amount of wear of the piston ring and the initial thickness; and taking, by the electronic control module, a remedial action based on the amount of damage to the piston ring. 
     In some embodiments, a machine may comprise a piston; a memory configured to store piston ring wear information; and an electronic control module. The electronic control module may be configured to: obtain, from the piston ring wear information stored in the memory, information identifying a previous amount of wear of the piston ring and information identifying an initial dimension of a coating of the piston ring; determine a piston ring wear rate based on a cylinder pressure associated with the piston; determine an amount of time between a current time and a time when the previous wear of the piston ring was calculated; calculate a current amount of wear of the piston ring based on the previous amount of wear of the piston ring, the amount of time, and the piston ring wear rate; calculate an amount of damage to the piston ring based on the current amount of wear of the piston ring and the initial dimension; and take a remedial action when the amount of damage to the piston ring exceeds a piston ring damage threshold. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross-sectional view of an engine according to an embodiment of the present disclosure; 
         FIG. 2A  is a cross-sectional view of a piston of the engine of  FIG. 1 ; 
         FIG. 2B  is another cross-sectional view of the piston of  FIG. 2A  with a piston ring; 
         FIG. 2C  is a cross-sectional view of the piston ring of  FIG. 2B ; 
         FIG. 2D  is another cross-sectional view of the piston ring of  FIG. 2B ; 
         FIG. 3  is a diagram of example components of a system that may be used to monitor and determine wear of the piston ring of  FIG. 2B  to determine damage to the piston ring; and 
         FIG. 4  is a flow chart of an example process performed by the system of  FIG. 3  for monitoring and determining wear of the piston ring of  FIG. 2B  to determine damage to the piston ring. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a cross-sectional view of an exemplary internal combustion engine  100  (or engine  100 ) according to an embodiment of the present disclosure. In some implementations, engine  100  may include a block  110  (or engine block  110 ) defining one or more bores  120  (or cylinder bores  12 ). A hollow liner  130  (or cylinder liner  130 ) may be disposed within each of the one or more bores  120 , and a head  180  (or cylinder head  180 ) may be connected (e.g., by way of a gasket  170 ) to block  110  to close off an end of a bore  120 , of the one or more bores  120 , and cylinder liner (or liner)  130 . A piston  200  may be slidably disposed within liner  130 , and piston  200  together with liner  130  and head  180  may define a combustion chamber  160 . Piston  200  may include an annular cooling passage  150 . Piston  200  and annular cooling passage  150  are described in more detailed below. In some implementations, engine  100  may include one or more combustion chambers  160  and the one or more combustion chambers  160  may be disposed in an “in-line” configuration, in a “V” configuration, in an opposing-piston configuration, or in any other suitable configuration. 
     In some implementations, piston  200  may be configured to reciprocate within liner  130  between a top-dead-center (TDC) position and a bottom-dead-center (BDC) position during a combustion event occurring with chamber  160 . More particularly, piston  200  may be pivotally connected to a crankshaft  140  by way of a connecting rod  190  (or rod  190 ), so that a sliding motion of each piston  200  within cylinder liner  130  results in a rotation of crankshaft  140 . Similarly, a rotation of crankshaft  140  may result in a sliding motion of piston  200 . In a four-stroke engine, piston  200  may move through four full strokes to complete a combustion cycle of about 720° of crankshaft rotation. These four strokes include an intake stroke (TDC to BDC), a compression stroke (BDC to TDC), a power stroke (TDC to BDC), and an exhaust stroke (BDC to TDC). Fuel (e.g., diesel fuel, gasoline, gaseous fuel, etc.) may be injected into combustion chamber  160  during the intake stroke. The fuel may be mixed with air and ignited during the compression stroke. Heat and pressure resulting from the fuel/air ignition may then be converted to useful mechanical power during the ensuing power stroke. Residual gases may be discharged from combustion chamber  160  during the exhaust stroke. 
     The number of components (of engine  100 ) shown in  FIG. 1  is provided for explanatory purposes. In practice, there may additional components, fewer components, different components, or differently arranged components than those shown in  FIG. 1 . 
       FIG. 2A  is a cross-sectional view of piston  200  of engine  100  of  FIG. 1 . In some implementations, piston  200  may generally consist of an integral crown  210  (or crown  210 ), a skirt  220 , and undercrown  230 . Skirt  220  be generally tubular (i.e., hollow and cylindrical), with a bearing support  240  (or support  240 ) formed therein. Support  240  may be configured to receive a wrist pin that pivotally connects piston  200  to rod  190  (referring to  FIG. 1 ). Support  240  may define a pin bore  250 . Piston pin bore (or piston bore)  250  may receive a piston pin (not shown). Crown  210  may be formed at end of piston  200  opposite support  240 , and may include an end face  270  and an annular side surface  280 . Undercrown  230  may correspond to an area under crown  210 . One or more ring grooves  290  may be cut into annular side surface  280  and configured to receive corresponding oil rings (not shown), compression rings (not shown), or another type of piston ring known in the art. A bowl  260  may be recessed within end face  270 , and a rim  262  (bowl rim  262 ) may be located at an intersection of bowl  260  and end face  270 . An annular cooling passage  150  may be formed in crown  210  between bowl  260  and grooves  290 . The circulation of engine oil or another coolant through passage  150  during operation of engine  100  may reduce a temperature of crown  210 . In some implementations, annular cooling passage  150  may define (or may correspond to) an oil gallery in which the engine oil may reside. With this configuration, the engine oil may function as a heat sink, causing combustion heat from inside bowl  260  to pass radially outward and downward in a direction toward annular cooling passage  150 . 
       FIG. 2B  is another cross-sectional view of piston  200  of  FIG. 2A  with a piston ring  292 . As illustrated in  FIG. 2B , one (or more) of grooves  290  may receive piston ring  292 . In some implementations, piston ring  292  may be a top piston ring of piston  200 . Alternatively, piston ring  292  may be another piston ring of piston  200 . 
       FIG. 2C  is a cross-sectional view of piston ring  292  of  FIG. 2B . Is illustrated in  FIG. 2C , a portion of piston ring  292  may include a coating  294 . In some implementations, coating  294  may have an initial dimension (e.g., an initial thickness X(0)) when piston ring  292  is first provided on one of grooves  290 . 
       FIG. 2D  is another cross-sectional view of the piston ring of  FIG. 2B . As illustrated in  FIG. 2D , coating  294  of piston ring  292  may wear over a period of time due cylinder pressure and cylinder force (e.g., based on piston  200  sliding up and down cylinder bore  120  and cylinder liner  130 ) and piston ring  292  may wear accordingly. In some implementations, a pattern of wear of coating  294  may be from an outer surface of piston ring  292  toward an inner surface of piston ring  292 , as illustrated in  FIG. 2D . In this regard, the thickness of coating  294  may be reduced (e.g., X(i)) over the period time as coating  294  experiences wear over the period of time. Accordingly, when coating  294  is worn out (e.g., when the thickness of coating  294  is zero), piston ring  292  may be damaged and may cause other components of piston  200  and/or engine  100  to experience a failure. In some implementations, an amount of wear of piston ring  292  may be based on an amount of reduction of the initial dimension of coating  294 . 
     The number of components shown in  FIGS. 2A-2D  is provided for explanatory purposes. In practice, there may additional components, fewer components, different components, or differently arranged components than those shown in  FIGS. 2A-2D . Additionally, the shape of piston ring  292  is provided as example shapes. In some implementations, the shape of piston ring  292  may be rectangular, may have tapers, or other unique geometry. Additionally, or alternatively, coatings may not only exist on the outer face (i.e. radial wear). Instead, coatings may also exist on the axial face of piston ring  292 . In this regard, as piston ring  292  moves up and down vertically in the groove, piston ring  292  may experience wear. 
       FIG. 3  is a diagram of example components of a system  300  that may be used to monitor and determine wear of piston ring  292  of  FIG. 2B  to determine damage to piston ring  292 . In some embodiments, the example components may include a memory  310 , an electronic control module (ECM)  320 , a display  330 , a sensor  340 , an input device  350 , and a communication interface  360 . The example components of system  300  may be implemented using hardware, software, and/or a combination of hardware and software. In some implementations, the example components of system  300  may be interconnected using wired connections, wireless connections, and/or a combination of wired connections and wireless connections. 
     In some implementations, engine  100  and one or more of the example components of system  300  may be included in a machine. For example, engine  100 , memory  310 , ECM  320 , display  330 , sensor  340 , input device  350  and/or communication interface  360  may be located in the machine. In some implementations, one or more of the example components of system  300  may be included in a back office. For example, memory  310 , ECM  320 , display  330 , sensor  340 , input device  350  and/or communication interface  360  may be located in the back office while engine  100  and sensor  340  may be located in the machine. 
     Memory  310  may include a random access memory (“RAM”), a read only memory (“ROM”), and/or another type of dynamic or static storage device (e.g., a flash, magnetic, or optical memory) that stores information and/or instructions for use by the example components, such as ECM  320 , to monitor and determine wear of piston ring  292  of  FIG. 2B  to determine damage to piston ring  292 . Additionally, or alternatively, memory  310  may include non-transitory computer-readable medium or memory, such as a disc drive, flash drive, optical memory, read-only memory (ROM), or the like. In some implementations, with respect to the information and/or the instructions for use by the example components, memory  310  may store information (e.g., obtained in real-time or near real-time by sensor  340 ) regarding temperature(s) of engine  100 , temperature(s) of piston  200 , temperature(s) of components of piston  200  (e.g., temperature(s) of crown  210 , rim  262 , undercrown  230 , etc.). Additionally, or alternatively, memory  310  may store information regarding one or more models as described in U.S. patent application Ser. No. 15/087,439 (incorporated herein by reference in its entirety). For example, the one or more models may include a combustion model, a heat flux model, a thermal model, and/or a damage model. In some implementations, memory  310  may store the information and/or the instructions in one or more data structures, such as one or more databases, tables, lists, trees, etc. 
     ECM  320  (or controller  320 ) may include any type of device or any type of component that may interpret and/or execute the information and/or the instructions stored within memory  310  to perform one or more functions. For example, ECM  320  may use the information and/or execute the instructions to monitor and determine wear of piston ring  292  to determine damage to piston ring  292  and/or components of piston  200 . In some implementations, ECM  320  may include a processor (e.g., a central processing unit, a graphics processing unit, an accelerated processing unit), a microprocessor, and/or any processing logic (e.g., a field-programmable gate array (“FPGA”), an application-specific integrated circuit (“ASIC”), etc.), and/or any other hardware and/or software. 
     In some embodiments, ECM  320  may obtain information from the example components and use the information to monitor and determine wear of piston ring  292  to determine damage to piston ring  292  and/or piston  200 . For example, ECM  320  may obtain information from sensor  340  and/or from memory  310  and use the information to monitor and determine wear of piston ring  292  to determine damage to piston ring  292  and/or piston  200 . In some implementations, ECM  320  may transmit, via a network (not shown), information regarding the wear of piston ring  292  and/or information regarding the damage to piston  200  to another device (e.g., at a back office system (not shown)) and/or another machine (not shown)). For example, ECM  320  may cause communication interface  360  to transmit the information regarding the wear of piston ring  292  and/or information regarding the damage to piston  200 . 
     Display  330  may include any type of device or any type of component that may display information. For example, display  330  may display information regarding the wear of piston ring  292  and/or information regarding the damage to piston  200 . In some implementations, display  330  may be a liquid crystal display (LCD), a light-emitting diode (LED) display, an organic light-emitting diode (OLED) display, and/or the like. 
     Sensor  340  may include any type of device(s) or any type of component(s) that may sense (or detect) information regarding engine  100  and/or piston  200 . In some implementations, sensor  340  may located at various portions of engine  100  and/or piston  200  to sense (or detect) information regarding engine  100  and/or piston  200 . For example, the information regarding engine  100  and/or piston  200  may include a speed of engine  100  (e.g., a rotational speed of crankshaft  140 ), a mass of engine  100  (e.g., component(s) of engine  100 ), an inertia load (e.g., based on the speed and/or the mass), a quantity of fuel being injected into combustion chamber  160  during each combustion cycle, a timing of the fuel being injected, a pressure of the fuel being injected, a flow rate of air entering combustion chamber  160  during each combustion cycle, a temperature of the air, a pressure of the air, a temperature of the engine oil in passage  150  (e.g., the oil gallery) and/or other fluid of engine  100 , a temperature of other components of engine  100  and/or piston  200  (e.g., crown  210 , rim  262 , etc.), a cylinder pressure (e.g., as piston  200  slides up and down cylinder bore  120  and cylinder liner  130 ) associated with piston  200 , a cylinder force, a cylinder pressure load, and/or the like. In some implementations, sensor  340  may include a pressure sensor (e.g., to detect machine strut pressures), a force gauge, a load cell, a piezoelectric sensor, and/or the like. 
     Input device  350  may include a component that permits a user to input information to one or more other components of the example components of system  300 . For example, the information, input by the user, may include a preference (of the user) for a frequency for monitoring and/or for determining the wear of piston ring  292  and the damage to piston  200 . Additionally, or alternatively, the information, input by the user, may include a manner (e.g., algorithm(s), parameters(s), etc.) for monitoring and/or determining the wear of piston ring  292  and/or the damage to piston  200 . In some embodiments, input device  360  may include a keyboard, a keypad, a mouse, a button, a camera, a microphone, a switch, a touch screen display, and/or the like. 
     Communication interface  360  may include a transceiver-like component, such as a transceiver and/or a separate receiver and transmitter that enables device  300  to communicate with other devices, such as via a wired connection, a wireless connection, or a combination of wired and wireless connections. For example, communication interface  360  may include an Ethernet interface, an optical interface, a coaxial interface, an infrared interface, a radio frequency (“RF”) interface, a universal serial bus (“USB”) interface, or the like. 
     The number of components shown in  FIG. 3  is provided for explanatory purposes. In practice, there may additional components, fewer components, different components, or differently arranged components than those shown in  FIG. 3 . 
       FIG. 4  is a flow chart of an example process  400  performed by the system of  FIG. 3  for monitoring and determining wear of the piston ring of the piston of  FIG. 2  to determine damage to the piston ring and/or the piston. In some implementations, one or more process blocks of process  400  may be performed by ECM  320 . For example, ECM  320  may perform one or more process blocks of process  400  automatically (e.g., without intervention/input from a user). In some implementations, one or more process blocks of  FIG. 4  may be performed by another device or a group of devices separate from or including ECM  320 , such as device(s) at a remote location (e.g., a back office). 
     As shown in  FIG. 4 , process  400  may include receiving information for determining wear of piston ring  292  (block  410 ). For example, ECM  320  may receive piston ring wear information that ECM  320  may use with respect to determining the wear of piston ring  292 . In some implementations, the piston ring wear information may be stored in memory  310  and ECM  320  may obtain the piston ring wear information from memory  310 . Additionally, or alternatively, the piston ring wear information may be stored in another memory (similar to or different than memory  310 ) and ECM  320  may obtain the piston ring wear information from memory  310 . Additionally, or alternatively, the piston ring wear information may be submitted by a user using input device  350  and ECM  320  may receive the piston ring wear information submitted by the user. Additionally, or alternatively, the piston ring wear information may be obtained by sensor  340  and ECM  320  may obtain the piston ring wear information from sensor  340 . 
     In some implementations, the piston ring wear information may include an indication that wear is to be determined for piston  200 . For example, the indication may submitted by a user using input device  350  and ECM  320  may receive the indication. Additionally, or alternatively, ECM  320  may obtain information from memory  310  and may identify the indication based on the information obtained from memory  310 . In some implementations, the information from memory  310  may include a time interval for ECM  320  to determine the wear of piston ring  292 . For example, the time interval may indicate that ECM  320  is to determine the wear of piston ring  292  at a frequency 0.01 Hz to 100 Hz. The time interval may be expressed in other units of time measurement. For example, the time interval may indicate that ECM  320  is to determine the wear of piston ring  292  every second, every minute, every hour, and/or the like. 
     Additionally, or alternatively, the piston ring wear information may include information identifying an initial dimension of coating  294  (e.g., when piston ring  292  is first installed on one of grooves  290 ). For example, the initial dimension of coating  294  may include an initial thickness of coating  294 . In some implementations, ECM  320  may use the initial thickness of coating  294  to determine an amount of damage to piston ring  292  based on the wear of coating  294 . For example, ECM  320  may determine a level of damage to piston ring  292  based on the wear of coating  294  with respect to the initial thickness (as will be explained in more detail below). In some implementations, the initial thickness may be different for each piston ring (e.g., based on physical parameters of piston ring  292 , such as geometry, shapes, sizes, contours, material properties such as coefficients of heat transfer, etc.). 
     Additionally, or alternatively, the piston ring wear information may include piston and/or engine information regarding the components of piston  200  and/or the components of engine  100 . For example, the piston and/or engine information may include the cylinder pressure and the cylinder force (e.g., obtained in real-time or near real-time by sensor  340 ). Additionally, or alternatively, the piston and/or engine information may include physical parameters (e.g., geometry, shapes, sizes, contours, material properties such as coefficients of heat transfer, etc.) of the components, relationships (e.g., a compression ratio, a bore stroke, valve timings, etc.) between the components, and/or the like. Additionally, or alternatively, the piston and/or engine information may include information regarding various fluids (fuel, lubrication, coolant, engine oil, air, etc.) of piston  200  and/or engine  100 . For example, the information regarding various fluids may include a makeup of the fluids, a concentration of the fluids, a quality of the fluids, other characteristics of the fluids, and/or the like. 
     As further show in  FIG. 4 , process  400  may include determining a piston ring wear rate (block  420 ). For example, ECM  320  may calculate the piston ring wear rate of piston ring  292  based on the piston ring wear information. For instance, ECM  320  may determine the piston ring wear rate of piston ring  292  based on one or more factors, including the cylinder pressure and/or the cylinder force (e.g., obtained by sensor  340  and/or included in piston ring wear information). In some implementations, ECM  320  may determine a relationship between cylinder pressures and piston ring wear rates. In some implementations, the relationship between the cylinder pressures and the piston ring wear rates may be based on one or more experiments, field studies, analyses, simulations for one or more different coatings and/or the like. For example, results of the one or more analyses, experiments, field study, and/or the like may identify a corresponding piston ring wear rate for each cylinder pressure. For instance, the results may be illustrated as a graph (or a chart) that identifies a corresponding piston ring wear rate for each cylinder pressure. Accordingly, based on the cylinder pressure and using the relationship between the cylinder pressures and the piston ring wear rates, ECM  320  may determine the piston ring wear rate corresponding to the cylinder pressure. 
     In some implementations, the piston ring wear rate may be measured (or expressed) in micro meters per hour (μm/h). Additionally, or alternatively, other units of measurement may be used to measure (or express) the piston ring wear rate. In some implementations, the piston ring wear rate may vary (or change) over period of time based on a change in the (current) thickness of coating  294  (e.g., based on a reduction in the thickness of coating  294 ). For example, the piston ring wear rate may decrease as the thickness of coating  294  is reduced. Accordingly, ECM  320  may re-determine the piston ring wear rate each time ECM  320  determines the wear of piston ring  292 . In some implementations, piston ring wear rates may vary based on physical characteristics of piston rings (e.g., properties, geometry, shape, etc.). In some implementations, the piston ring wear rate may vary based on other dimension of coating  294 . 
     In some implementations, ECM  320  may calculate an effective piston ring wear rate based on the piston ring wear rate (calculated in block  420 ) and one or more factors, such as a wear rate modifier. In some implementations, the wear rate modifier may be based on an amount of time since start up of engine  100 , a start and a stop frequency of engine  100 , a load ramp rate (e.g., information regarding a load of engine  100  upon start up), and/or the like. Additionally, or alternatively, the wear rate modifier may be based on oil temperature, oil degradation/quality, and/or the like. In some implementations, information regarding the amount of time since start up of engine  100 , the start and the stop frequency of engine  100 , the load ramp rate, the oil temperature, and/or the oil degradation/quality may be included in the information regarding engine  100  and/or piston  200  obtained by sensor  340 . In some implementations, ECM  320  may determine the wear rate modifier. In some implementations, ECM  320  may obtain the wear rate modifier from the piston ring wear information. 
     In some implementations, ECM  320  may calculate the effective piston ring wear rate based on a mathematical combination of the piston ring wear rate (or base piston ring wear rate) and the wear rate modifier. For example, ECM  320  may calculate the effective piston ring wear rate using the following equation: 
       {dot over ( X )}( i )′= A*{dot over (X)} ( i )  EQ. 1
         wherein:
           {dot over (X)}′ is the effective piston ring wear rate,   i is the current iteration,   A is the wear modifier, and   {dot over (X)} is the base piston ring wear rate.   
               

     In some implementations, ECM  320  may update the piston ring wear information (stored in memory  310  and/or another memory) based on the piston ring wear rate (or the effective piston ring wear rate when calculated). 
     As further show in  FIG. 4 , process  400  may include determining piston ring wear (block  440 ). For example, ECM  320  may calculate the wear of piston ring  292  based on the piston ring wear rate (determined in block  420 ) or the effective piston ring wear rate (calculated in block  430 ) when calculated. In some implementations, ECM  320  may calculate the wear of piston ring  292  based on a mathematical combination of the piston ring wear rate (or the effective piston ring wear rate) and one or more other factors. For example, ECM  320  may calculate the wear of piston ring  292  using the following equation: 
         X ( i )= X ( i− 1)+{dot over ( X )}( i )*Δ t   EQ. 2
         wherein:
           i is the current iteration (of the calculation of the wear of piston ring  292 ),   X(i) is the wear of piston ring  292  (or the current wear of piston ring  292 ),   X(i−1) is the previous wear of piston ring  292 ,   {dot over (X)} is the piston ring wear rate, and   Δt is the amount of time between a current time and a time (prior to the current time) when the previous wear of piston ring  292  was calculated (Δt may be based on or correspond to the time interval for ECM  320  to determine the wear of piston ring  292 ).   
               

     As explained above, the effective piston ring wear rate may be used instead of the piston ring wear rate (or base piston ring wear rate). As also explained above, an amount of wear of piston ring  292  may be based on an amount of reduction of the initial dimension of coating  294 . In some implementations, the previous wear of piston ring  292  may refer to an amount of wear of piston ring  292  up until the time (prior to the current time) when the previous wear of piston ring  292  was calculated. In this regard, the piston pin bore  250  (or the current piston pin bore  250 ) may refer to an additional amount of wear of piston ring  292  up until the current time. In some implementations, information identifying the previous wear of piston ring  292  and information identifying the time when the previous wear of piston ring  292  was calculated may be included in the piston ring wear information. In this regard, ECM  320  may determine the current time as a time to calculate the wear of piston ring  292  based on the time interval and the time when the previous wear of piston ring  292  was calculated. For example, ECM  320  may determine that the time interval has elapsed since the time when the previous wear of piston ring  292  was calculated and, accordingly, determine that the wear of piston ring  292  is to be calculated at the current time. Additionally, or alternatively, ECM  320  may determine Δt based on the time interval and the time when the previous wear of piston ring  292  was calculated. Additionally, or alternatively, ECM  320  may determine Δt based on the current time and the time when the previous wear of piston ring  292  was calculated. 
     In some implementations, the wear of piston ring  292  may be measured (or expressed) in micro meters (μm). Additionally, or alternatively, other units of measurement may be used to measure (or express) the wear of piston ring  292 . In some implementations, ECM  320  may update the piston ring wear information based on the wear of piston ring  292  (or the current wear of piston ring  292 ). For example, ECM  320  may update the previous wear of piston ring  292  with the current wear of piston ring  292 . Accordingly, the current wear of piston ring  292 , included in the piston ring wear information (stored in memory  310  and/or another memory), may become the previous wear of piston ring  292 . 
     As further show in  FIG. 4 , process  400  may include determining damage relating to the wear of piston ring  292  (block  450 ). For example, ECM  320  may calculate an amount of damage to piston ring  292  based on the wear of piston ring  292  (determined in block  440 ) and the initial thickness (e.g., included in the piston ring wear information). In some implementations, ECM  320  may determine the amount of damage to piston ring  292  as a mathematical combination of the wear of piston ring  292  (determined in block  440 ) and the initial thickness. For example, ECM  320  may calculate the amount of damage to piston ring  292  using the following equation: 
         D=X ( i )/ X (0)  EQ. 4
         wherein:
           D is the amount of damage to piston ring  292 ,   i is the current iteration (of the calculation of the current wear of piston ring  292 ),   X(i) is the wear of piston ring  292  (or the current wear of piston ring  292 ), and   X(0) is the initial thickness.   
               

     In some implementations, the amount of wear of piston ring  292  may be based on the amount of reduction of the initial dimension of coating  294  (e.g., the amount of reduction of the initial thickness of coating  294 ). In some implementations, the amount of damage to piston ring  292  may be expressed as a percentage (e.g., a percentage of the initial thickness). For example, assume the initial thickness of coating  294  is 20 μm. Further assume that the amount of wear of piston ring  292  (i.e., the amount of reduction of the initial thickness or amount of wear of coating  294 ) is 15 μm. Accordingly, the amount of damage to piston ring  292  would be 15 μm/20 μm or 75%. In this regard, ECM  320  may determine a level (or a percentage) of damage to piston ring  292  based on the calculated damage and may take remedial action if the level of damage meets and/or exceeds a threshold (as will be described in more detail below). Additionally, or alternatively, ECM  320  may determine that piston ring  292  is completely worn and damaged when the current thickness of coating  294  reaches zero. For example, ECM  320  may determine a failure of piston ring  292  when the thickness of coating  294  reaches zero. 
     In some implementations, the various equations and associated elements, described herein, to determine the amount of damage to piston ring  292  may form a piston damage model. In this regard, the various equations are provided as example equations. In some implementations, the associated elements (and/or additional elements) may be used in different mathematical combinations and/or different equations to determine the amount of damage to a piston ring. In some implementations, the piston damage model may be included in the piston ring wear information. 
     As further show in  FIG. 4 , process  400  may include determining whether the damage exceeds a threshold (block  450 ). For example, ECM  320  may determine whether the amount of damage to piston ring  292  (determined in block  440 ) exceeds a piston ring damage threshold. In some implementations, the piston ring damage threshold may correspond to an amount of wear of coating  294  that causes (or starts to cause) excessive blowby of exhaust gases into a crankcase of engine  100  (which house crankshaft  140 ), thereby compromising oil quality. In some implementations, the piston ring damage threshold may be included in the piston ring wear information. In some implementations, the piston ring damage threshold may be vary based on physical parameters of each piston ring. 
     As further shown in  FIG. 4 , if the damage exceeds the piston ring damage threshold (block  460 —YES), then process  400  may include taking a remedial action (block  470 ). For example, if ECM  320  determines that the amount of damage to piston ring  292  (determined in block  450 ) exceeds the piston ring damage threshold, ECM  320  may take a remedial action. In some implementations, the remedial action may include causing information to be displayed via display  330 . For example, the information may indicate that the amount of damage to piston ring  292  has exceeded the piston ring damage threshold and that piston  200  may be damaged and/or may fail if piston  200  continues to be used (or, in other words, if piston  200  is not replaced or serviced). Additionally, or alternatively, the information may indicate that engine  100  is to be shut down or derated to prevent additional wear and/or damage to piston ring  292 , that engine  100  is to be serviced, that piston  200  is to be replaced or serviced, and/or the like. Additionally, or alternatively, the information may include instructions for servicing engine  100 , instructions for servicing piston  200  (e.g., replacing and/or repairing piston  200 ), information identifying piston ring  292  and a location of piston ring  292  within engine  100  (for example, if engine  100  includes multiple pistons), and/or the like. In some implementations, the information may be transmitted to a remote location (e.g., a back office system) and/or another device. For example, ECM  320  may cause the information to be transmitted to the remote location and/or the other machine. In some implementations, the information may enable characteristics/attributes of a similar piston (e.g, properties, geometry, shape, etc.) to be modified during manufacture so as to reduce a wear rate of a piston ring during similar operating conditions. 
     Additionally, or alternatively, the remedial action may include causing service instructions to be provided. Additionally, or alternatively, the remedial action may include causing service of engine  100  and/or piston  200  to be automatically scheduled. Additionally, or alternatively, the remedial action may include may modify an operation of engine  100 . For example, ECM  320  may cause engine  100  to slow down, decelerate, and/or be shut down to prevent additional damage to piston  200 . 
     In some implementations, each remedial action described above may be associated with a respective amount of wear of piston ring  292  (with each amount of wear corresponding to a respective level of severity of damage to piston ring  292 , piston  200 , and/or engine  100 ). Accordingly, ECM  320  may select a remedial action based on the amount of wear of piston ring  292 . 
     As further shown in  FIG. 4 , if the damage count does not exceed the piston ring damage threshold (block  460 —NO), then process  400  may return to block  410 . In some implementations, if the damage count does not exceed the piston ring damage threshold (block  460 —NO), then process  400  may return to any one of block  410 , block  420 , block  430 , block  440 , or block  450 . In some implementations, with respect to block  420 , the piston ring wear rate may vary over a period of time based on the wear of piston ring  292 . Accordingly, as explained above, ECM  320  may re-determine the piston ring wear rate each time ECM  320  determines the wear of piston ring  292 . 
     INDUSTRIAL APPLICABILITY 
     The disclosed system may be used in any application where an increase in reliability of an engine and components of an engine is desire. The disclosed system may increase engine reliability by monitoring and determining an amount of wear of a piston ring, determining an amount of damage to the piston ring based on the amount of wear, and taking a remedial action when the amount of damage exceeds a threshold. In some implementations, ECM  320  may determine the piston ring wear rate, the effective piston ring wear rate, the amount of wear of piston ring  292 , and/or the amount of damage to piston ring  292  in real-time or near real-time. In some implementations, ECM  320  may predict a time (e.g., date and/or time) when engine  100  and/or piston  200  may begin experiencing damage and/or when engine  100  and/or piston  200  may begin experience a failure based on one or more factors (e.g., the piston ring wear rate, the effective piston ring wear rate, the amount of wear of piston ring  292 , the amount of damage to piston ring  292 , the time interval for ECM  320  to determine the amount of wear, the previous amount of wear, other information include in the piston ring wear information, a pattern of operation of engine  100 , and/or the like). In this regard, as part of taking the remedial action, ECM  320  may cause information regarding the prediction to be displayed via display  330 , may cause information indicating that engine  100  and/or piston  200  are to be serviced and/or replaced at or before the predicted time to be displayed via display  330 , may cause engine  100  and/or piston  200  to replaced, cause a service of engine  100  and/or piston  200  to be scheduled, and/or the like. 
     The disclosed system may have broad applicability. In particular, the system may be applicable to any type and design of piston  200 , and may be useful during design and/or selection of piston  200  prior to use of piston  200  within engine  100 . For example, information associated with and performance parameters measured from an existing engine may be used by ECM  320  to simulate wear of an engine and components of the engine. The results of the simulation may then be used to design and/or select application-specific pistons. In addition, the system may provide information regarding the amount of damage to piston ring  292 , and the information may remain accurate as engine  100  wears (as the piston ring wear information is updated based on wear conditions). In addition, the system may be useful across multiple configurations or platforms of engines. The disclosed concepts can be used during development of the engine components based on historic engine data, as desired. In particular, the disclosed concepts can be used to determine the status of the engine components given particular operating conditions. For example, based on a calculated amount of damage calculated for the engine components when exposed to the particular operating conditions, properties and/or geometry of the engine components can be changed so as to reduce the amount damage for the same components exposed to the same operating conditions. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed system. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed system. For example, it may be possible for engine  100  to not have cylinder liner  130 , if desired, and for piston  200  to reciprocate directly within cylinder bores  120 . Additionally, one or more of the parameters used to determine the amount of wear of piston ring  292  may vary based on one or more factors relating to piston  200  and/or engine  100 , such as operating conditions, properties, shapes, sizes, contours, geometry, and/or the like. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents. 
     No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. While the present disclosure has been referring to monitoring or determining wear of a piston ring of a piston of an engine, one skilled in the art would appreciate that the present disclosure may similarly apply to monitoring or determining wear of one or more other engine components (including one or more of the engine components of engine  100  described above). In this regard, any reference to engine  100  may refer to engine  100  as a whole and/or one or more components of engine  100 . Similarly, any reference to piston  200  may refer to piston  200  as a whole and/or one or more components of piston  200 . Also, as used herein, the articles “a” and “an” are intended to include one or more items, and may be used interchangeably with “one or more.” Furthermore, as used herein, the term “set” is intended to include one or more items, and may be used interchangeably with “one or more.” Moreover, as used herein, the “reduction of the initial dimension of coating” and the “reduction in the thickness of coating” may be used interchangeably to refer to coating wear, face wear, coating thickness wear, and/or the like. Where only one item is intended, the term “one” or similar language is used. Also, as used herein, the terms “has,” “have,” “having,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise.