Abstract: One embodiment of the present invention includes an internal combustion engine system designed to increase exhaust temperature when operating with a low mechanical load—such as idle operation. This increased exhaust temperature is provided to operate aftertreatment equipment. Exhaust temperature is raised by operating a portion of the engine pistons in a brake mode to increase loading on a remainder of the pistons operating in a combustion mode to drive the engine. Fuel provided to pistons operating in the combustion mode is regulated to maintain speed of the engine within a desired idle speed range.

Abstract: A method of controlling a cylinder deactivation system is disclosed. Information from one or more sensors is received by a control unit. The control unit compares the current values of a parameter with one or more prohibited ranges in order to determine if cylinder deactivation should be prohibited. The one or more prohibited ranges are discrete ranges, each with a lower limit and an upper limit.

Abstract: This control device for an internal combustion engine includes a variable intake valve device and a variable exhaust valve device; and it performs fuel cut-off for a plurality of cylinders of the internal combustion engine. And it further includes: an intake valve control means which, when the fuel cut-off execution condition has come into effect, controls the variable intake valve device, so as to keep in a closed state the intake valve of a cylinder, for which an exhaust valve is not kept in a closed state; and an exhaust valve control means which, when the fuel cut-off execution condition has come into effect, controls the variable exhaust valve device, so as to keep in an open state an exhaust valve of at least a pair of cylinders, between which gases in the pair of cylinders come and go via an exhaust passage as the pistons operate.

Abstract: An exhaust temperature control system for a displacement on demand (DOD) diesel engine includes a first and a second cylinder and an air intake that selectively enables air flow into the first cylinder. A fuel injector selectively enables fuel flow into the first cylinder. A controller increases an exhaust temperature of the diesel engine by closing the air intake and disabling fuel flow through the fuel injector to deactivate the first cylinder.

Abstract: A method for determining degraded valve operation. According to the method, valve degradation can be determined from the duration of a spark event. This method allows for the determination of both intake and exhaust valve degradation.

Abstract: An engine control system comprises a torque control module and a fueling control module. The torque control module selectively generates a deactivation signal for a first cylinder of a plurality of cylinders of an engine based on a torque request. The fueling control module halts fuel delivery to the first cylinder based on the deactivation signal. The torque control module increases a spark advance of the engine at a first time after the fueling control module halts fuel injection for the first cylinder. The first time corresponds to an initial time combustion fails to occur in the first cylinder because fuel delivery has been halted.

Abstract: A system includes a cylinder selection module and a valve deactivation module. The cylinder selection module selects cylinders of an engine for active fuel management. The valve deactivation module deactivates intake valves of selected cylinders of the engine before deactivating exhaust valves of the selected cylinders when an engine speed of the engine is less than or equal to a predetermined speed.

Abstract: A method of regulating a throttle opening of an engine in a hybrid electric vehicle system includes initiating a fuel-cut off operating mode of the engine, monitoring an engine speed during said fuel cut-off operating mode and regulating the throttle opening based on the engine speed during the fuel-cut off mode to maintain a manifold absolute pressure (MAP) of the engine above a threshold MAP.

Abstract: A method for controlling an internal combustion engine having a plurality of cylinders using electronic valve actuation, including operating a first portion of the cylinders in a homogeneous charge compression ignition (HCCI) mode, operating a second portion of the cylinders in a non-HCCI mode, and adjusting the valve timing of the second portion of cylinders to dynamically load level the engine in response to a transient torque demand. A system for controlling a multiple cylinder internal combustion engine, including a first group of cylinders to operate in an HCCI mode, a second group of cylinders to operate in a non-HCCI mode, and an engine controller operably coupled to the first and second groups of cylinders, said controller to adjust the valve timing of the second group of cylinders to dynamically load level the engine in response to a transient torque demand.

Abstract: A degradation estimating apparatus for an unburned fuel component adsorption catalyst, which is connected with an internal combustion engine and has an unburned fuel component adsorbent and an oxygen storage component is provided. The apparatus includes a degradation estimating unit for making estimation for a degradation of the unburned fuel component adsorption catalyst on the basis of a first term and a second term. The first term is from the cancellation of the fuel supply to detecting a variation of an upstream side air-fuel ratio occurring due to the increase of the reductant quantity in the exhaust gas. The second term is from the cancellation of the fuel supply to detecting of a variation of the downstream side air-fuel ratio due to an increase of the reductant quantity.

Abstract: In a diesel engine 10 equipped with a fuel injection device 50 having a fuel supply pump 53 for pressingly sending a fuel, a common rail 52 for accumulating the fuel pressingly sent from the fuel supply pump, injectors 51 for injecting the fuel into a cylinder by an electronic control, a coolant water temperature sensor 64 for detecting an engine coolant water temperature and a fuel injection quantity map for calculating a target common rail pressure, total amount of injections, the number of multistage injection, the respective injection quantity and the respective injection quantity timing, the diesel engine 10 comprises a total injection quantity increasing means for increasing the total amount of injections in the injection quantity control arithmetic means and an injection number reduction avoidance means for avoiding that the number of multistage injections are changed by the total injection quantity increasing means when the engine is transferred to a cold state to a warming state.

Abstract: A method and a device for operating an internal combustion engine, in particular of a motor vehicle, permitting optimal compensation of all losses of the internal combustion engine in half-engine operation. The internal combustion engine has several cylinder banks, at least a first cylinder bank being deactivatable, and, during deactivation of the first cylinder bank, the first cylinder bank losses and the losses of a second cylinder bank being taken into account during activation of the second cylinder bank, and the default value of the second cylinder bank quantity being formed in several steps. In at least one of these steps, the first cylinder bank losses and the second cylinder bank losses are taken into account for forming the default value.

Abstract: Cylinder deactivation is a proven solution to improve engine fuel efficiency. The present invention is related to Dynamic Cylinder Deactivation (DCD) solution to conventional internal combustion engine. DCD is an energy saving method based on engine thermodynamics and residual heat recovery. It deactivates all the cylinders within the engine alternatively and dynamically, totally different from traditional sealed-valves cylinder deactivation solutions. DCD has many advantages over traditional sealed-valves cylinder deactivation. Thermodynamic efficiency gain, residual heat recovery, high Lambda and “Air-Hybrid” are the most attractive features of DCD. DCD also makes engine displacement variable.

Abstract: An internal combustion engine has a separate exhaust passage for each one of banks. An exhaust purifying catalyst is provided in each exhaust passage. The mass flow rates G1, G2 of exhaust gas that flow through the exhaust passages are individually estimated. The flow rate of exhaust gas is individually adjusted per each bank by controlling the operation of each one of exhaust gas recirculation valves such that the difference between the estimated mass flow rates G1, G2 is decreased.

Abstract: An air-fuel ratio control apparatus for an internal combustion engine, including fuel cut state detection means for detecting the state of fuel cut in which the feed of fuel into the internal combustion engine is stopped, and catalyst deterioration decision means for deciding the deterioration of a catalyst on the basis of a period which is expended since the detection of the release of the state of the fuel cut by the fuel cut state detection means, until the output value of a second air-fuel ratio sensor agrees with a predetermined reset decision value near a target value, and the manipulation quantity of an average air-fuel ratio on the upstream side of the catalyst as is based on second air-fuel ratio feedback control means. Thus, the deterioration of the catalyst can be decided at a high precision.

Abstract: A system, method, and software for controlling regeneration and desulfurization of a NOx adsorber is disclosed. An electronic control unit is connected with an engine for selectively controlling operation of the engine between a rich operating mode and a lean operating mode. A NOx adsorber is in fluid communication with a flow of exhaust from the engine. A NOx adsorber manager module is executable by the electronic control unit to determine the need to operate in a de-NOx mode or a de-SOx mode. If the NOx adsorber manager module determines a need exists to operate in the de-NOx mode and the de-SOx mode at the same time, the NOx adsorber manager module executes the de-SOx mode.

Abstract: A variety of methods and arrangements for improving the fuel efficiency of internal combustion engines are described. Generally, an engine is controlled to operate in a skip fire variable displacement mode. Feedback control is used to dynamically determine the working cycles to be skipped to provide a desired engine output. In some embodiments a substantially optimized amount of air and fuel is delivered to the working chambers during active working cycles so that the fired working chambers can operate at efficiencies close to their optimal efficiency. In some embodiments, the appropriate firing pattern is determined at least in part using predictive adaptive control. By way of example, sigma delta controllers work well for this purpose. In some implementations, the feedback includes feedback indicative of at least one of actual and requested working cycle firings. In some embodiments, the appropriate firings are determined on a firing opportunity by firing opportunity basis.

Abstract: A variety of methods and arrangements for improving the fuel efficiency of internal combustion engines are described. Generally, selected combustion events are skipped during operation of the internal combustion engine so that other working cycles can operate at a better thermodynamic efficiency. In one aspect of the invention, an engine is controlled to operate in a variable displacement mode. In the variable displacement mode, fuel is not delivered to the working chambers (e.g. cylinders) during selected “skipped” working cycles. During active (“non-skipped”) working cycles, a maximum (e.g., unthrottled) amount of air and an optimized amount of fuel is delivered to the relevant working chambers so that the fired working chambers can operate at efficiencies closer to their optimal efficiency. A controller is used to dynamically determine the chamber firings required to provide the engine torque based on the engine's current operational state and conditions.

Abstract: A method of transitioning an engine to a cylinder deactivation mode may include determining a ratio of time that the engine is operating in the cylinder deactivation mode for an engine operating condition relative to a total time of engine operation in the operating condition, determining a number of transitions from a full cylinder mode to the cylinder deactivation mode during the operating condition, determining a transition modifier based on the ratio and number, and modifying a transition criterion based on the transition modifier.

Abstract: An active vibratory noise control apparatus reduces vibratory noise which is produced in the passenger compartment of a vehicle based on vibratory noise generated by a variable-cylinder internal combustion engine that can selectively be operated in a full-cylinder operation mode in which all of the cylinders are operated and a partial-cylinder operation mode in which some of the cylinders are out of operation. The active vibratory noise control apparatus has a partial-cylinder operation mode determining circuit for determining whether the variable-cylinder internal combustion engine is in the partial-cylinder operation mode or not. Depending on a determined result from the partial-cylinder operation mode determining circuit, a transistor is turned on or off to switch an amplifying circuit which drives a speaker into and out of operation.

Abstract: A gas sensor diagnostic method includes: a fuel supply detecting step of detecting an interruption of a fuel supply to the internal combustion engine, and a restart of the fuel supply after the interruption of the fuel supply; a response time period accumulating step of determining a response time period by accumulating a first time period that the sensor output value reaches from a first threshold value to a second threshold value after the detection of the interruption of the fuel supply, and a second time period that the sensor output value reaches from a third threshold value to a fourth threshold value after the detection of the restart of the fuel supply after the interruption of the fuel supply; and an abnormal state diagnosing section of determining an abnormal state of the gas sensor when the response time period is greater than a predetermined time period.

Abstract: An engine control apparatus is configured to prevent damage to a catalytic converter caused by the occurrence of temperature differences. The engine control apparatus is particularly useful in a catalytic converter having a thin-walled ceramic carrier. The engine control apparatus prohibits cutting of the fuel supply during vehicle deceleration for a prescribed amount of time after operation of either an engine speed limiter component, which cuts the fuel supply when the engine speed exceeds an allowable engine speed, or a vehicle speed limiter component, which cuts the fuel supply when the vehicle speed exceeds an allowable vehicle speed.

Abstract: A multicylinder internal combustion engine, which can simplify its control and is advantageous against thermal loads or vibrations includes a cylinder head with intake valves and exhaust valves arranged therein. Valve actuators are provided for openably operating the intake valves and exhaust valves, respectively. A cylinder head cover forms, in combination with the cylinder head, a valve actuator chamber with the valve actuators accommodated therein. At least some of the valve actuators are deactivatable to disable their corresponding cylinders. The multicylinder internal combustion engine is a V-shaped internal combustion engine provided with a front bank and rear bank. The cylinders on opposite ends in a direction of a crankshaft are set as full-time operating cylinders.

Abstract: A method for operating an engine having at least one cylinder that may be deactivated and a fuel system operating with an alcohol fuel blend, comprising of adjusting a range of operating parameters in which the at least one cylinder is deactivated, where said range is adjusted as the alcohol blend of the fuel varies.

Abstract: System in which the depollution apparatus is associated with an oxidation catalyst-forming device, and the engine is associated with a common rail for feeding it with fuel and adapted to implement the strategy of regeneration using at least one postinjection of fuel into the cylinders. In the system, a regeneration request can be detected, a state in which the vehicle accelerator pedal is being raised can be detected, the temperature downstream from the catalyst-forming means can be acquired, and it can be determined, on the basis of this temperature, the maximum duration for applying postinjections during a stage in which the engine is returning to idling as a result of the accelerator pedal being raised, for immediately cutting off postinjection as soon as the duration of postinjection use has reached the maximum duration.

Abstract: An internal combustion engine includes multiple cylinders. A partial set of the cylinders may be temporarily shut off. Fuel is introduced briefly into at least one of the shut off cylinders and combusted in an at least essentially torque-neutral way during the cylinder shut off period.

Abstract: A method of control fueling of a cylinder in an internal combustion engine, the cylinder having at least two intake valves, the method comprising of operating in a first mode with one active intake valve and one inactive intake valve during a cycle of the cylinder operating in a second mode with two active intake valves during a cycle of the cylinder and adjusting a fuel injection from an injector configured to deliver fuel through at least the two intake valves, where the fuel injection adjustment is responsive to a transition in modes and based on whether the transition is from the first mode to the second mode, or from the second mode to the first mode.

Abstract: A system and method to control engine valve operation during periods of cylinder deactivation of an internal combustion engine. Electromechanical valves are controlled in a manner to reduce fuel consumption and emissions during cylinder deactivation periods of an internal combustion engine.

Abstract: A method for operating an engine having at least one cylinder that may be deactivated and a fuel system operating with an alcohol fuel blend, comprising of adjusting a range of operating parameters in which the at least one cylinder is deactivated, where said range is adjusted as the alcohol blend of the fuel varies.

Abstract: An engine control system comprises a torque control module and a fueling control module. The torque control module selectively generates a deactivation signal for a first cylinder of a plurality of cylinders of an engine based on a torque request. The fueling control module halts fuel delivery to the first cylinder based on the deactivation signal. The torque control module increases a spark advance of the engine at a first time after the fueling control module halts fuel injection for the first cylinder. The first time corresponds to an initial time combustion fails to occur in the first cylinder because fuel delivery has been halted.

Abstract: An engine control system is provided. The system includes: an engine torque module that estimates torque output based on charge energy; and a cylinder mode module that controls fuel cut-off and adjusts spark timing to the engine based on the torque output.

Abstract: In a fuel pump control system for an internal combustion engine whose operation is switched between cut-off-cylinder operating mode during which some of the cylinders are non-operative and full-cylinder operating mode during which all of the cylinders are operative and having a fuel injector connected to the fuel supply line and supplied with fuel pressurized by the fuel pump, it is discriminated whether the operation of the engine is in the full-cylinder operating mode or in the cut-off-cylinder operating mode, the operation of the fuel pump is controlled based on the discriminated operating mode of the engine, i.e., is controlled such that the delivery flow rate of the fuel pump when the engine is discriminated to be in the cut-off-cylinder operating mode, is reduced relative to that when the engine is discriminated to be in the full-cylinder operating mode, thereby reducing the power consumption and operating noise of the fuel pump.

Abstract: A method for controlling an engine including at least a first cylinder having a first piston and a second cylinder having a second piston, at least one of said first and second cylinders having at least an adjustable valve, the method comprising before engine rotation: closing electrically actuated valves in at least the first and the second cylinder; fueling at least said first cylinder with a first fuel amount based on a position of the first piston and said second cylinder with a second fuel amount based on a position of the second piston; performing a first spark in at least one of said first cylinder and said second cylinder; and applying a starter motor to assist engine starting rotation; after engine rotation, firing each cylinder of the engine in a sequential firing order without changing a number of strokes in any cylinder of the engine.

Abstract: A method of controlling fuel injection in an engine of a vehicle comprises reactivating fuel injectors based on release or decrease of driver braking during deceleration fuel shut off operation. According to another aspect, a method of controlling fuel injection in an engine of a vehicle comprises reactivating fuel injectors based on release or decrease of driver braking during deceleration fuel shut off; and increasing air flow to a cylinder before reactivation of fuel injectors in response to said release or decrease of driver braking to enhance torque response. The methods allow an engine to exit DFSO earlier by making use the brake input and effort, which provides time to reactivate the fuel injection and stabilize torque control prior to tip-in.

Abstract: Various systems and methods are disclosed for carrying out combustion in a fuel-cut operation in some or all of the engine cylinders of a vehicle. Further, various subsystems are considered, such as fuel vapor purging, air-fuel ratio control, engine torque control, catalyst design, and exhaust system design.

Abstract: A method to operate a multi-cylinder direct-injection engine in one of a controlled auto-ignition and a spark-ignition combustion mode is described. Engine operation and an operator torque request are monitored. Fuel delivery to a portion of the cylinders is selectively deactivated and torque output from non-deactivated cylinders is selectively increased to achieve the operator torque request when the monitored engine operation is above a predetermined threshold. An engine operating point at which an engine load demand exceeds an operating capability of the engine in a stoichiometric HCCI mode is identified. The engine is selectively operated in an unthrottled spark-ignition mode with at least one cylinder unfueled and torque output from the remaining cylinders is selectively increased.

Abstract: An engine cranking system includes fuel injectors that are associated with multiple combustion chambers of an engine. The fuel injectors include a first fuel injector that is associated with a first combustion chamber. A second fuel injector is associated with a second combustion chamber. A control module is coupled to the fuel injectors and operates the first fuel injector in a deactivated state for a first chamber cycle during cranking of said engine. The first chamber cycle includes intake and exhaust strokes and is associated with a first combustion chamber.

Abstract: A method of operating an engine is provided. The engine includes at least one cylinder communicating with an intake manifold via an intake manifold valve and an exhaust manifold via an exhaust manifold valve, the cylinder including a piston arranged within the cylinder, wherein the piston is coupled to a crankshaft of the engine. The method comprises discontinuing combustion in the cylinder during a plurality of cycles of the engine; during the plurality of cycles, operating the exhaust manifold valve and the intake manifold valve to provide a net flow of gases from the exhaust manifold to the intake manifold via the cylinder and adjusting a torque signature provided to the crankshaft during each cycle by the piston responsive to an operating condition.

Abstract: The exhaust gas purifying catalysts sometimes generate H2S which emits exhaust odor under reducing atmosphere. However, in the ordinary air-fuel ratio control, it takes much time to establish sufficient oxygen atmosphere for suppressing H2S emission when the maximum oxygen storage amount which the exhaust gas purifying catalyst can store is large. Thus, the fuel cut control apparatus of an internal combustion engine executes fuel cut to bring oxygen in the exhaust gas into an excessive state when the maximum oxygen storage amount is a predetermined amount or more. As a result, sufficient oxygen can be stored in the exhaust gas purifying catalyst. Even when the maximum oxygen storage amount of the exhaust gas purifying catalyst is smaller than the predetermined amount, if the temperature of the exhaust gas purifying catalyst is lower than predetermined temperature, fuel cut is executed.

Abstract: A compression ignition engine (10) has a control system (40), one or more combustion chambers (12), and fuel injectors (42, 44) for injecting fuel into the combustion chambers. The control system controls fueling using a result of the processing of engine speed and engine load to select a particular domain for engine operation (HCCI, HCCI+CD, or CD, —FIG. 1). When the processing selects HCCI, the engine is fueled to cause alternative diesel combustion (such as HCCI) in all combustion chambers. When the processing selects CD, all combustion chambers are fueled for conventional diesel combustion. When the processing selects HCCI+CD, a first group of combustion chambers are fueled for HCCI combustion and a second group for CD combustion. Each group (G1, G2) has its own EGR valve (34, 38) and turbocharger (22, 24).

Abstract: A selective combustion starting system and method selectively provides a proper amount of fuel to one or more combustion chambers in an internal combustion engine. The particular combustion chambers selected depend upon the state of the piston of the combustion chamber and the volume of the combustion chamber, which is dependent upon the position of the piston. Once proper amounts of fuel have been provided to the one or more combustion chambers, the resulting fuel air mixture in the combustion chambers is ignited and combusts to rotate the crankshaft of the engine to commence normal operation of the engine.

Abstract: An air fuel ratio controller for an internal combustion engine includes an exhaust gas sensor, an identifier and a control unit. The exhaust gas sensor detects oxygen concentration of exhaust gas. The identifier calculates model parameters for a model of a controlled object based on the output of the exhaust gas sensor. The controlled object includes an exhaust system of the engine. The control unit is configured to use the model parameters to control the air-fuel ratio so that the output of the exhaust gas sensor converges to a desired value, and to stop the identifier from calculating the model parameters during and immediately after the engine operation with a lean air-fuel ratio. The calculation of the model parameters may be also stopped during and immediately after fuel-cut operation that stops fuel supply to the engine.

Abstract: An internal combustion engine is provided that includes a high pressure feed line, and a plurality of fuel injectors fluidly connected to the high pressure feed line, each being operable to inject a fuel into the engine. The engine further includes an electronically controlled flow disabler disposed between the high pressure feed line and each one of the fuel injectors. Each of the flow disablers includes an actuator operable to move a valve member toward a closed position at which the flow disabler blocks a fuel flow to the respective fuel injector.

Abstract: A method for controlling a first and second injector of an engine, the first injector located in a first cylinder of the engine and the second injector located upstream of, and configured to inject fuel into, the first and a second cylinder of the engine, the method comprising of decreasing total injection from the first and second injectors when decreasing injection from the second injector, and increasing total injection from the first and second injectors when increasing injection of the second injector.

Abstract: A multi-cylinder group engine system operable in at least a first mode and a second mode, where in the first mode a first and second cylinder group combust air and fuel, and where in the second mode at least one of the first and second cylinder group combusts air and fuel and the other one of the first and second cylinder group pumps air without injected fuel, the engine system comprising of a first linear exhaust gas sensor disposed in a first exhaust passage to measure air fuel exhausted from the first cylinder group; a first switching type exhaust gas sensor disposed in a second exhaust passage to measure air-fuel exhausted from the second cylinder group; a second linear exhaust gas sensor disposed downstream of a junction between the first exhaust passage and the second exhaust passage; and a controller configured to validate a reading of the first linear exhaust gas sensor during the first mode of engine operation based on a reading of the second linear exhaust gas sensor when a lean air-fuel ratio is co

Abstract: A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic engine controller. This provides the engine controller with a look up table of what compression ratio and exhaust gas rates should be at each speed and load. The engine controller also balances at least one of combustion phasing and energy release among a plurality of cylinders in order to enable higher load operation.

Abstract: A method controls the intake and/or the exhaust of at least one deactivated cylinder (10, 12, 14, 16) of an internal-combustion engine operating in four phases. The cylinder includes an intake with an intake valve (28), an exhaust with an exhaust valve (34), a fuel injector (42), an ignition (48) and a piston sliding within this cylinder between a position corresponding to its top dead center (PMHa, PMHd) and a position corresponding to its bottom dead center (PMBa, PMBd). When the engine runs at low or partial loads, one of the valves (28, 34) of the deactivated cylinder is opened in the vicinity of a top dead center (PMHa, PMHd). This valve is closed in the vicinity of the next top dead center (PMHd, PMHa).

Abstract: An internal combustion engine includes multiple combustion chambers. The supply of fuel into at least one subset of the combustion chambers can temporarily be interrupted. It is provided that the fuel be injected into the combustion chambers directly and during a switchover phase for interrupting or resuming fuel injection into the subset of combustion chambers, at least temporarily via multiple injections.

Abstract: A method and a system for regenerating an exhaust gas treatment device in an internal combustion engine having at least one cylinder are presented. The method comprises regenerating the device by inhibiting combustion in at least one of the engine cylinders and controlling the fuel injection system so that fuel is allowed into at least one of the cylinders in which combustion is inhibited.

Abstract: A method for controlling an internal combustion engine having a plurality of cylinders using electronic valve actuation, including operating a first portion of the cylinders in a homogeneous charge compression ignition (HCCI) mode, operating a second portion of the cylinders in a non-HCCI mode, and adjusting the valve timing of the second portion of cylinders to dynamically load level the engine in response to a transient torque demand. A system for controlling a multiple cylinder internal combustion engine, including a first group of cylinders to operate in an HCCI mode, a second group of cylinders to operate in a non-HCCI mode, and an engine controller operably coupled to the first and second groups of cylinders, said controller to adjust the valve timing of the second group of cylinders to dynamically load level the engine in response to a transient torque demand.