Abstract: A method includes controlling an aircraft during descent, and controlling the engine pressure ratio of a jet engine so that the engine has a substantially equal pressure at the exhaust, and at the front of the engine during the descent.

Abstract: The subject application involves a method of controlling operation of a gas turbine. The method includes determining a first temperature associated with a portion of the gas turbine during operation of said gas turbine, and sensing an operational parameter of the gas turbine during operation of the gas turbine. An ambient pressure in an ambient environment of the gas turbine is also sensed, and the operational parameter corrected using the ambient pressure sensed in the ambient environment of the gas turbine to establish a corrected operational parameter. A threshold temperature is determined based at least in part on the corrected operational parameter, and a backup routine is initiated to limit operation of the gas turbine when the temperature associated with the gas turbine is greater than or equal to the threshold temperature.

Abstract: An embodiment of the present invention has the technical effect of utilizing a model-based system and real time data to adjust a parameter of at least one valve. An embodiment of the present invention may reduce the need of multiple sensors within a fuel system by integrating a model-based controller with real-time or approximately real-time data to adjust a parameter of at least one valve. An embodiment of the present invention may utilize a model-based controller to calculate the fuel flow through the at least one valve, in or near real-time.

Abstract: Embodiments of the invention can provide systems, methods, and an apparatus for modifying the power output and efficiency of a combined cycle power plant. According to one embodiment where a combined cycle power plant includes a compressor, a gas turbine, a combustor, and a heat recovery steam generator, excess air from the compressor can be extracted and expanded to generate power. The expanded air can then be mixed with at least one combustible fuel to generate a heated combustion product. The heated combustion product can be mixed with exhaust gas from the gas turbine to increase the temperature of the exhaust gas prior to introduction to the heat recovery steam generator. This increase in temperature of the exhaust gas from the gas turbine provides additional energy for generating steam and power and improves performance of the heat recovery steam generator.

Abstract: A method and systems for engine control of a vehicle propulsion system are provided. The system includes a plurality of engine model modules executing independently and programmed to receive engine operating condition values from a plurality of sensors positioned on an engine wherein each of the plurality of engine model modules is programmed to determine an estimate of a process parameter of a location in the engine where a sensor is not available, not present at the location, has failed, or is determined to be inaccurate. The system also includes an estimate source selector configured to determine model blending factors and a model blending module configured to determine an estimated virtual sensor value using the determined estimates from at least two of the plurality of engine model modules and the model blending factors.

Abstract: A method of operating a drive system for a load is disclosed. The drive system may have an electric motor/generator and a gas turbine engine. The engine may have a combustor, and main and pilot flow paths via which fuel is supplied to the combustor. The engine may be operable in low and standard emissions modes. A proportion of the fuel that is supplied to the combustor via the pilot flow path may be greater in the standard emissions mode than in the low emissions mode. The method may include determining an engine power requirement of the load, and whether the engine power requirement of the load is sufficiently large to operate the engine in the low emissions mode. Additionally, the method may include operating the electric motor/generator if the engine power requirement of the load is not sufficiently large to operate the engine in the low emissions mode.

Abstract: Systems, devices, and methods for controlling a fuel supply for a turbine or other engine using direct and/or indirect indications of power output and optionally one or more secondary control parameters.

Abstract: According to this invention, artificial force gradient means (9a) of a throttle control lever (4) for a turbo-engine comprise means (17) for adjusting the intensity of the artificial force gradient.

Abstract: A system and method for estimating the impact of compressor fouling in a combined cycle power block. The current performance of the combined cycle power block is determined and normalized to one or more reference conditions. A baseline performance of a gas turbine of the combined cycle power block is also determined. A predicted performance of the combined cycle power block is then determined by substituting the baseline performance of the gas turbine for the current performance of the gas turbine. A recoverable impact to the combined cycle power block due to compressor fouling is then determined by subtracting the normalized current performance from the predicted performance and a recoverable impact to the fuel consumption of the combined cycle power block is determined from the recoverable impact.

Abstract: A gas turbine performance analysis system includes a performance computation module for receiving an actual measured value of an inlet air temperature introduced to a compressor, a compressor pressure ratio, and a flow rate of fuel supplied to the gas turbine, and for calculating and outputting values of the gas turbine's power output and exhaust temperature based on these actual measured values. A performance estimation module evaluates the performance of the gas turbine based on the deviation between the values of power output and exhaust temperature outputted from the performance computation module and the actual measured values of power output and exhaust temperature. An adjustment module calculates a corrected value of the fuel flow rate based on the actual measured values of inlet air temperature, compressor pressure ratio and fuel flow rate, and inputs the corrected fuel flow rate value into the performance computation module.

Abstract: A gas turbine engine control component includes at least one electronic device, electronics such as an integrated circuit associated with the device, and a thermoelectric cooler for cooling the electronics mounted in a compartment. The thermoelectric cooler may be disposed in or on a wall of the compartment with a heat sink connected to a hot side of the thermoelectric cooler and a cold side of the thermoelectric cooler exposed to an interior of the compartment. Data about and/or operating instructions for the device may be stored in memory on the integrated circuit. The data may be calibration information for the device. A bus connector is connected to the integrated circuit for transferring operating instructions and/or data from the integrated circuit out and/or out of the component. A controller or control system incorporating these devices and components have the devices electronically connected to the integrated circuit.

Abstract: A system and method for narrowing an assessment of root cause to a single stage within a gas turbine engine module using coupling factors and known instrumentation non-repeatability. Embodiments examine certain root cause (RC) effects that manifest themselves as coupling levels, or ratios (CR), between an engine module's efficiency change ?? and its flow parameter change ?FP.

Abstract: A technique provides a remote adjustment to a portion of an airplane engine. The technique involves attaching a remote adjuster to the portion of the engine at a proximate location to the engine while the engine is not running. The portion is configured to receive a direct manual adjustment from a user while the engine is running and while the user is in direct physical contact with the portion. The technique further involves, after attaching the remote adjuster to the portion of the engine, supplying user input to the remote adjuster at a distal location to the engine to provide a remote adjustment to the portion of the engine through the remote adjuster in place of the direct manual adjustment from the user. The technique further involves, after supplying the user input to the remote adjuster, removing the remote adjuster from the portion of the engine.

Abstract: Systems and methods for controlling compressor extraction air flows from a compressor of a turbine system during engine turn down are provided. In one embodiment, a method for controlling compressor extraction air flows from a compressor of a turbine system during turn down includes a control unit monitoring one or more operating parameters of a turbine system associated with an exit temperature of a combustor of the turbine system. The method further includes the control unit detecting one or more operating parameters meeting or exceeding a threshold associated with a decrease in the exit temperature of the combustor. In response to detecting one or more operating parameter meeting or exceeding the threshold, a control signal is transmitted to at least one variable orifice located in the turbine system causing at least one variable orifice to alter at least one extraction air flow from the compressor.

Abstract: A system and method are provided for controlling the temperature of engine bleed air from a turbofan gas turbine engine. The system includes a fan air valve and a fan air valve controller. The fan air valve is adapted to receive a flow of fan air from a turbofan gas turbine engine intake fan. The fan air valve is coupled to receive valve position commands and is configured, in response to the valve position commands, to move to a valve position to thereby control the engine bleed air temperature. The fan air valve controller is configured to implement a linear quadratic regulator (LQR) control. The fan air valve controller is adapted to receive a plurality of sensor signals, each sensor signal representative of one or more system parameters, and is configured, in response to the sensor signals, to supply the valve position commands to the fan air valve.

Abstract: When controlling an engine having a Variable Turbine Geometry (VTG) the VTG is closed some predicted time period before an up-gear shift is performed. This is advantageous because when the gear shift begins the engine breaking is already maximized and full engine brake can be obtained during the entire gear shift operation.

Abstract: The invention relates to a method for detecting a rotating stall fault in a compressor (12) which is driven by means of a three-phase current motor (8) fed by an inverter. According to the invention, an instantaneous estimated value (?m) which is calculated from measured power converter output currents (iS1, iS2, iS3) and a measured rotational-speed-proportional signal (?) is compared with an instantaneous setpoint value (m*) determined from a measured rotational-speed-proportional signal (?) and a predetermined rotational-speed-proportional signal (?*), in such a way that in the case of inequality a signal (SRS) is generated which indicates that the rotating stall fault has occurred. In this way, it is possible for the rotating stall fault to be detected without pressure sensors and/or oscillation pickups in a compressor (12) which is driven with a three-phase current motor (8) fed by inverter.

Abstract: The present invention relates to a method and to a device (D) enabling a health check to be performed on at least a first turbine engine (M1) of a rotorcraft, the rotorcraft being provided with first and second turbine engines (M1 and M2) controlled respectively by first and second control means (MC1 and MC2). The device is remarkable in that it comprises check means (C) provided with main means (C1), the main means (C1) controlling the first and second control means (MC1 and MC2) so that the surveillance parameters of the first and second turbine engines (M1 and M2) respectively reach the real first and second final values (V1f and V2f) as determined in accordance with the method of the invention.

Abstract: A system and method are provided for controlling the start-up of a gas turbine engine having an exhaust gas temperature (EGT) sensor. A determination is made as to whether the EGT sensor is available or unavailable. The gas turbine engine is commanded to accelerate at a nominal acceleration rate during the start-up operation if the EGT sensor is available, and to accelerate at an off-nominal acceleration rate during the start-up operation if the EGT sensor is unavailable. The off-nominal acceleration rate is lower than the nominal acceleration rate.

Abstract: Apparatus and methods are disclosed for determining internal engine characteristics using acoustic-vibration data. Exemplary such data are passive acoustic pyrometer data. Acoustic-vibrational frequencies emanating from a running engine are detected and compared to frequencies having known relationships to particular operating characteristics of the engine. In an example, the dominant frequency or other prominent frequency emanating from an internal-combustion chamber of a turbine engine is detected and used to determine the fuel-to-air ratio in the chamber. The determined data are used for performing adjustments or optimizations of engine performance, such as adjusting the fuel-to-air ratio as required or desired. In a similar manner, operating characteristics of other engines or engine-like environments, including furnaces and boilers, can be determined.

Abstract: A gas turbine output learning circuit is configured to compute a current combustion gas temperature TIT at an inlet of a gas turbine by linear interpolation by use of two characteristic curves A and B respectively representing relations between a pressure ratio and an exhaust gas temperature in the cases of the combustion gas temperature at the inlet of the gas turbine at 1400° C. and 1500° C., then to compute ideal MW corresponding to this combustion gas temperature TIT at the inlet of the gas turbine by linear interpolation according to 1400° C.MW and 1500° C.MW (temperature controlled MW), and then to correct the 1400° C.MW and the 1500° C.MW so as to match the ideal MW with a measured gas turbine output (a power generator output).

Abstract: A gas turbine engine is provided and includes a combustor having a first interior in which a first fuel is combustible, a turbine into which products of at least the combustion of the first fuel are receivable, a transition zone, including a second interior in which a second fuel and the products of the combustion of the first fuel are combustible, a plurality of fuel injectors which are configured to supply the second fuel to the second interior in any one of a single axial stage, multiple axial stages, a single axial circumferential stage and multiple axial circumferential stages, a compressor, by which air is supplied to the first and second interiors for the combustion therein, and a control system configured to control relative amounts of the air to the first and second interiors and relative amounts of the first and second fuels supplied to the first and second interiors.

Abstract: A gas turbine engine is provided and includes a combustor having a first interior in which a first fuel is combustible, the first fuel including natural gas and/or a blend of natural gas and alternate gas receivable by a fuel circuit from an external source, a turbine, a transition zone, including a second interior in which a second fuel, the second fuel including an unblended supply of the alternate gas receivable by the fuel circuit from the external source, and the products of the combustion of the first fuel are combustible, and a plurality of fuel injectors, which are structurally supported by the transition zone and coupled to the fuel circuit, and which are configured to supply the second fuel to the second interior in any one of a single axial stage, multiple axial stages, a single axial circumferential stage and multiple axial circumferential stages.

Abstract: In a process for protection of a gas turbine (1) from damage caused by pressure pulsations (P), pressure pulsations (P) occurring during the operation of the gas turbine (1) are measured, from the measured pressure pulsations (P), a pulsation-time signal (PZS) is generated, the pulsation-time signal (PZS) is transformed into a pulsation-frequency signal (PFS), from the pulsation-frequency signal (PFS), a pulsation level (PL) is determined for at least one specified monitoring frequency band (12), the pulsation level (PL) is monitored for the occurrence of at least one specified trigger condition, and, when the at least one trigger condition occurs, a specified protective action (16) is carried out.

Abstract: One embodiment according to the present invention is a unique system for gas turbine engine control. Other embodiments include unique apparatuses, systems, devices, and methods relating to gas turbine engines. Further embodiments, forms, objects, features, advantages, aspects, and benefits of the present invention shall become apparent from the following description and drawings.

Abstract: The invention relates to a method for controlling at least one actuator for actuating the cowlings of a thrust inverter in a turbojet engine, the actuator being driven by an electric motor including a relative position sensor providing information on the evolution of the movement thereof, wherein the motor is controlled based on the instantaneous position of the cowling in at least one portion of the movement thereof between an open position and a closed position, the instantaneous position of the cowling being determined from at least one reference position absolute data and relative position data relative to said reference position provided by the relative position sensor of the motor, wherein in case the actuation is resumed after an interruption, a new determination of the reference position is initiated.

Abstract: A method and algorithm are provided to operate a gas turbine at baseload in an emission compliant capable mode to avoid combustion dynamics while operating with cold fuel and hot fuel combustion hardware. The method includes performing a gas turbine operational sequence such as a startup to an emission compliant capable mode. A gas fuel temperature is measured. The gas turbine is operated in the emissions compliant capable mode according to a designated fuel split for avoiding combustion dynamics when a temperature for a gas fuel is below a designated value. A determination is made whether a modified wobbe index for the gas fuel is below an emissions compliant value. An alarm is activated if the modified wobbe index is below the emissions compliant value to notify the operator of a potential emissions shift.

Abstract: An apparatus and a method for ascertaining a gap between a stationary member and a rotating member are disclosed. At least a reference beam and a signal beam, which have different focal lengths or which diverge/converge at different rates, are fixed to the stationary member and proximate to each other. The beams are projected across a gap between the stationary member and the rotating member toward the rotating member. The reference and signal beams are reflected by the translating member when it intersects the reference and signal beam, and the reflected reference and signal pulses are obtained. One or more features of the reflected reference pulse and the reflected signal pulse, such as a rise time of the pulses, a fall time of the pulses, a width of the pulses and a delay between the reflected reference pulse and the reflected signal pulse, among other factors, are obtained. The width of the gap is obtained using at least one of these factors.

Abstract: A pulse detonation combustor (PDC)-based hybrid engine control system includes a programmable controller directed by algorithmic software to control a rotational shaft speed of the PDC-based hybrid engine, an air inlet valve rotational speed for the PDC, and a fuel fill time period for the PDC in response to a corresponding low pressure turbine (LPT) shaft speed signal or a power difference signal based on a difference between desired power and actual power produced by the PDC-based hybrid engine and further in response to a fuel fill time signal for the PDC, such that a desired fuel fill fraction and stoichiometric ratio are maintained and further such that a mass air flowrate from an air compressor matches a mass air flowrate ingested via the PDC while the PDC-based hybrid engine is operating in an acceleration mode or a deceleration mode.

Abstract: A lean blowout protection system and method is provided that facilitates improved lean blowout protection while providing effective control of turbine engine speed. The lean blowout protection system and method selectively and gradually biases the lean blowout (LBO) schedule based on current engine data. This facilitates improved lean blowout protection while providing effective control of turbine engine speed and temperature.

Abstract: A system and method that provides improved fault detection in turbine engines is disclosed. The fault detection system provides the ability to detect symptoms of engine faults based on a relatively limited number of engine parameters that are sampled relatively infrequently. The fault detection system includes a sensor data processor that receives engine sensor data during operation and augments the sensor data. The augmented data set is passed to a fuzzy logic inference system that determines the likelihood that a fault has occurred. The inference system output can then be passed to a diagnostic system where evaluation of the output may yield a detailed diagnostic result and a prediction horizon.

Abstract: A method of monitoring the health of a gas turbine engine of at least a pair of engines of an aircraft for example. The method comprising the steps of: a) obtaining steady state readings from predetermined sensors on the engines; b) calculate a percentage difference of the steady state readings from a unique engine linear synthesis model for each engine; c) compare the difference between the percentage differences for each engine and d) where this difference exceeds a predetermined value issue a warning as to an engine health problem. Maintenance of the engine can therefore be advantageously scheduled.

Abstract: An embodiment of the present invention has the technical effect of controlling an air preheating system integrated with a gas turbine. The present invention may offer the benefit of extending a turndown range by beating the air (hereinafter “inlet-air”) entering the compressor of the gas turbine. The present invention may also offer the benefit of increasing an efficiency of the powerplant.

Abstract: A system and method for controlling the rotational speed of a gas turbine engine in an aircraft includes appropriate devices and processes for determining a pressure of lubricant supplied to the turbine engine, and for determining a maneuver state of the aircraft. The rotational speed of the gas turbine engine is controlled based at least partially on the determined pressure and the determined maneuver state. Thus, if the aircraft is in a maneuver state that may cause a reduction or loss of lubricant to the gas turbine engine, the rotational speed of the gas turbine engine can be reduced to a magnitude sufficient to increase turbomachine tolerance to the reduced or no lubricant flow.

Abstract: A fuel controller for a combustion system in a gas turbine having a combustion system, a fuel supply, a pressure control valve proximate the combustion system and a first pressure sensor proximate the pressure control valve, the fuel controller including: a proportional-integrated (PI) logic unit generating a control command for the pressure control valve and receiving input signals representing a desired fuel pressure at the pressure control valve and an input signal from the first pressure sensor representing an actual fuel pressure at the pressure control valve, and a plurality of control gains stored in electronic memory of the controller, wherein each control gain is applicable to a predefined operating condition of the gas turbine, and wherein the controller determines which set of control gains is to be applied by the PI logic unit based on an actual operating condition of the gas turbine.

Abstract: An engine windmill relight method is described for use with a fuel control system (FCS) having a metering valve (MV), the method comprising the steps of determining a desired fuel delivery rate, and moving the MV to a nominal fuel delivery setting higher than that corresponding to the desired fuel delivery rate.

Abstract: A thermal management system for a gas turbine powerplant with an engine oil line and an engine fuel line incorporates a heat transfer control module that includes a reversible heat pump with a heat pump compressor for circulating working fluid in forward and reverse directions through a working fluid line of the heat pump. The heat control module also includes a first heat exchanger having a heat exchange path for the working fluid between the compressor and a heat pump expansion valve and another heat exchange path for the engine oil. A second heat exchanger has a heat exchange path for the working fluid between the compressor and the expansion valve and another heat exchange path for the engine fuel. The heat pump can be operated in forward or reverse directions depending on whether heat is to be transferred from the engine oil or the fuel to the heat pump working fluid.

Abstract: An isolation method and system is described for distinguishing between turbine case cooling (TCC) and high pressure turbine (HPT) performance faults. A trend is observed in gas path parameter data during cruise and a resulting percent ? signature across the shift in the gas path parameters is assignable to either an HPT or TCC performance fault. During either fault, exhaust gas temperature (EGT) will shift upward. Since take-off EGT margin is calculated from take-off data, the shift, or lack of shift in EGT margin may be used to differentiate between TCC and HPT faults.

Abstract: Methods and apparatus are provided for verifying proper operation of a gas turbine engine output torque sensor using a speed sensor, and using the speed sensor as a backup torque sensor. Gas turbine engine output torque is sensed using a reference torque sensor, and gas turbine engine output shaft rotational speed is sensed. Gas turbine engine output torque is calculated from the sensed gas turbine engine output shaft rotational speed. The sensed gas turbine engine output torque is compared to the calculated gas turbine engine output torque to determine if the reference torque sensor is operating properly. The gas turbine engine is controlled at least partially based on the sensed gas turbine engine output torque if the reference torque sensor is determined to be operating properly, and is controlled at least partially based on the calculated output torque if the reference torque sensor is determined to be not operating properly.

Abstract: A system and method is provided that facilitates improved fault detection. The fault detection system provides the ability to detect symptoms of fault in the fuel system of a turbine engine. The fault detection system captures selected data from the turbine engines that is used to characterize the performance of the fuel system. The fault detection system includes a feature extractor that extracts salient features from the selected sensor data. The extracted salient features are passed to a classifier that analyzes the extracted salient features to determine if a fault is occurring or has occurred in the turbine engine fuel system. Detected faults can then be passed to a diagnostic system where they can be passed as appropriate to maintenance personnel.

Abstract: A method for providing cooling and power is provided. The method includes providing a cooling unit that includes a first turbine rotatably coupled to a generator by a first shaft and providing a power unit that includes a second turbine rotatably coupled to a compressor by a second shaft. The method further includes coupling the power unit in flow communication with the cooling unit to form a turbine assembly, wherein the first shaft and the second shaft are independently rotatable relative to one another.

Abstract: Methods and apparatus are provided for determining refrigerant charge in a vapor compressor system (VCS) of an aircraft. The methods and apparatus comprise the following steps of, and/or means for, generating a data set from historical data representative of a plurality of VCS operating conditions over time, identifying one or more steady-state data points in the generated data set, forming a revised data set that includes at least the steady-state data points, using principal components analysis (PCA) to derive values for a plurality of minimally correlated input variables, supplying the derived values for the plurality of minimally correlated input variables and the corresponding values for the VCS refrigerant charge in the revised data set to a nonlinear neural network model, and deriving a simulator model characterizing a relationship between the plurality of minimally correlated input variables and the VCS refrigerant charge.

Abstract: An exemplary sensor for an aircraft includes a sensor mountable within an aircraft and operative to communicate wirelessly communications to a distributed aperture antenna. The sensor is operative to harvest energy from the aircraft to power the sensor.

Abstract: Modern ECU's control fuel flow and efficiency of high performance vehicles. Converting a standard fossil fuel vehicle or boat to oxy-hydrogen requires monitoring of additional factors such as oxy-hydrogen burn rates, oxy-hydrogen flow, oxy-hydrogen temperature, oxy-hydrogen production rates and overall factors such as barometric pressure, altitude, humidity, ambient temperatures etc. When a vehicle operating as a hybrid, experiences difficulties with oxy-hydrogen production, burn rate, fuel flow, or operating temperature, the ECU must compensate and revert back to fossil fuel operating status, or suffer engine failure and potentially costly mechanical damages.

Abstract: A method of operating a gas turbine engine is provided. The method includes introducing a fuel into a combustor, detecting a failure of ignition of the fuel, and preventing ignition until the introduced fuel is substantially removed from the gas turbine engine.

Abstract: A gas thruster is configured to supply thrust over a relatively wide range, from a relatively low value to a relatively high thrust value, and exhibits relatively fine minimum impulse bit (MIB) performance. The gas thruster includes a thrust nozzle, a main stage, a main valve element, and a pilot valve. The gas thruster responds to thruster control signals supplied to the pilot valve and is configured such that for commands of relatively short duration, only the pilot valve responds and relatively low thrust is produced. Conversely, for command or relatively longer duration, the pilot valve and main valve element both respond and relatively higher thrust is produced.

Abstract: A system for controlling the clearance between a turbine blade and the turbine casing that includes an impingement cooling manifold attached to a turbine casing, a temperature sensing device for determining the temperature of the turbine casing, a blower, a control system logic for determining the setting temperature of the casing, and a controller for controlling the blower, wherein the blower forces air onto the impingement cooling manifold to cool the casing towards the setting temperature and control the clearance.

Abstract: A method is disclosed of determining the power demand on a power subsystem (2) of a system (1) by optimising a respective demand-dependent operating characteristic based on one or more operating conditions affecting the power subsystem, the method comprising: using a system-authority (3, 14) to determine system-level power demand limits on the basis of a system-level objective associated with an operating period; inputting the power demand limits to a separate power control processor (4, 16) configured for regulating the power demand on the power subsystem (2); determining each of said operating conditions; and using the power control processor (4, 16) autonomously to determine the overall power demand on the power subsystem (2) within said system-level limits, based on each of said operating conditions, thereby to optimise said operating characteristic. A method of regulating the power demand during the operating period is also disclosed.

Abstract: Methods and systems for controlling a dynamic response in a gas turbine fuel control system are provided. The control system includes a component model adapted to regulate a fuel supply pressure for a gas turbine, a pressure sensor adapted to sense a pressure of fuel supplied to the gas turbine, and a feedback module including integral plus state feedback, the feedback module adapted to provide a positive feedback reference signal to the component model such that a response time of the gas turbine fuel control system to changes in fuel pressure is facilitated being reduced.

Abstract: A method and systems for controlling an engine are provided. The system includes an engine model programmed to receive engine operating condition values from a plurality of sensors on an engine. The engine model is programmed to determine a plurality of engine operating parameter values. The system also includes a processor configured to compare the operating parameter values to a predetermined allowable range for the operating parameter and control the operation of the engine to facilitate returning the determined operating parameter to the allowable range or maintaining the determined operating parameter within the allowable range, output the determined operating parameter values to a user, and/or generate maintenance requests based on the comparison.