Abstract: An engine provided with a variable timing mechanism (B) able to control a closing timing of an intake valve (7) and a variable compression ratio mechanism (A) able to change a mechanical compression ratio and controlling the closing timing of the intake valve (7) to control the amount of intake air fed into a combustion chamber (5). To obtain an output torque in accordance with the required torque even when the atmospheric pressure changes, when the atmospheric pressure falls, the closing timing of the intake valve (7) is made to approach intake bottom dead center and the mechanical compression ratio is reduced.

Abstract: A control apparatus and method, and an engine control unit for an internal combustion engine are provided for restraining a torque step and sudden fluctuations in rotation when an air/fuel mixture combustion mode is switched among a plurality of combustion modes, and for improving the fuel economy. A control apparatus of an internal combustion engine operated with a combustion mode switched between a stratified combustion mode and a uniform combustion mode comprises an ECU. The ECU calculates an ignition manipulated variable to cancel out a change in the engine rotational speed associated with the switching of the combustion mode when a first-time injection ratio changes during idle rotational speed control, and calculates an intake manipulated variable to cancel a change in the engine rotational speed caused by the ignition manipulated variable when the first-time injection ratio changes.

Abstract: A control system which is capable of compensating for and suppressing the influence of a periodic disturbance on a controlled object more quickly, even when the controlled object is subjected to the periodic disturbance the amplitude of which periodically changes, thereby enhancing the stability and the accuracy of control. The control system includes an ECU. The ECU calculates disturbance compensation values for compensating for a periodic disturbance by searching maps and tables, in timing of generation of each pulse of a CRK signal. The ECU calculates control inputs at a predetermined control period, with predetermined control algorithms, according to the disturbance compensation values read in at the control period, respectively.

Abstract: Systems and methods for controlling automotive powertrains using a distributed control architecture are disclosed. A distributed control system may include a supervisory control unit for controlling one or more powertrain subsystems, and one or more subsystem control units in communication with the supervisory control unit. The supervisory control unit can be configured to execute a central optimization algorithm that computes variables from across multiple powertrain subsystems, and then outputs a number of globally approximated command values to each associated subsystem control unit. In some embodiments, the central optimization algorithm can be configured to solve a global cost function or optimization routine. One or more of the subsystem control units can be configured to execute a lower-level algorithm or routine, which can comprise a higher-fidelity model than that used by the central optimization algorithm.

Abstract: An intake air amount control system for an internal combustion engine, which is capable of ensuring high robustness and improving controllability in intake air amount control, to thereby improve drivability and reduce exhaust emissions. A control system of an internal combustion engine, which variably controls the amount of intake air drawn into cylinders as desired via a variable intake valve actuation assembly includes an ECU 2. The ECU 2 calculates a cylinder intake air amount Gcyl and a target intake air amount Gcyl_cmd based on a controlled object model, a vector ?s of all model parameters of the controlled object model with an identification algorithm, calculates a target auxiliary intake cam phase ?msi_cmd based on the vector ?s with a sliding mode control algorithm, and controls the variable intake valve actuation assembly according to the target auxiliary intake cam phase ?msi_cmd.

Abstract: A requested injection time InjT necessary for a fuel injector to inject a fuel per one combustion cycle is computed in response to a position of an accelerator manipulated by a driver, an injectable time InjMax per one combustion cycle is computed on the basis of an engine speed, and whether or not the requested injection time InjT is larger than the injectable time InjMax is determined. Then, when it is positively determined that the requested injection time InjT is larger than the injectable time InjMax, it is estimated that an alternate fuel (for example an alcohol fuel) other than a regular fuel (for example gasoline) is blended with a fuel in a fuel tank.

Abstract: A system for controlling a multiple cylinder internal combustion engine having a plurality of cylinders with electronically actuated valves (EVA) is presented. The system is designed to improve the torque delivery of an EVA engine that operates a portion of cylinders in an HCCI combustion mode.

Abstract: In a V-type engine provided with a variable valve timing mechanism and variable valve lift mechanism for an intake valve, a torque difference between respective banks is obtained. In a region in which an opening area of the intake valve is larger than a threshold, valve timing of the intake valve by the variable valve timing mechanism is corrected so as to reduce the torque difference, whereas in a region in which the opening area of the intake valve is smaller than the threshold, lift characteristics of the intake valve by the variable valve lift mechanism is corrected so as to reduce the torque difference.

Abstract: An injection pulse output portion outputs an injection pulse to the fuel injector based on a target fuel injection timing and a target fuel injection quantity. A fuel injection monitor portion computes an actual fuel injection timing and an actual fuel injection quantity and determines that there is an malfunction in fuel injection when a difference between the actual fuel injection timing and a target fuel injection timing is larger than a specified value and when a difference between the actual fuel injection quantity and a target fuel injection quantity is larger than a specified value. According to a combustion mode, a torque monitor portion defines one of an air-quantity-base actual torque and a fuel-quantity-base actual torque as a malfunction determination actual torque to determine whether a torque malfunction exists. When the fuel injection malfunction exists, the air quantity base torque is defined as the malfunction determination actual torque.

Abstract: To improve power performance while avoiding or suppressing surging, an engine control device comprises a VVT mechanism for varying the open/close timing of an intake valve, and the occurrence of surging is determined by comparing an engine rotation variation width with a surge determination threshold. When it is determined that surging has occurred, an ignition timing surge correction amount is set at a value that has been corrected in an advancement direction, and the ignition timing is corrected in the advancement direction by the ignition timing surge correction amount. Further, a VVT surge correction amount by which the open/close timing of the intake valve is corrected using the intake VVT mechanism is set at a value that has been corrected in a retardation direction, and a control current value for operating the intake VVT mechanism is corrected in the retardation direction by the VVT surge correction amount.

Abstract: A fuel system and powertrain for a flexible fuel system vehicle utilizes a controller system to control variables in an engine and the final drive optimize operating efficiency of the vehicle while using an alcohol-gasoline blend. The controller system regulates engine operating variables such as fuel pressure, fuel flow, air-fuel flow, air-fuel temperature, and valve timing. The controller system regulates engine operating variables such as transmission gear selection and gear changing as well as differential ratio changes.

Abstract: Injectors each having a piezo actuator are assigned to cylinders of an internal combustion engine. A regulator device is configured for furnishing a cylinder-specific controlled variable and a command variable to a controller whose primary manipulated variable is a variable representing an electrical power supplied to the piezo actuator during a control cycle. A manipulated variable splitting unit is provided whose input variable is a regulator-determined regulator value of the primary manipulated variable and is configured for determining a total value of the primary manipulated variable according to the regulator value. It is also configured for splitting the total value into a primary value of the primary manipulated variable and into a secondary value of a secondary manipulated variable according to a lower and/or upper threshold value of the total value.

Abstract: A valve timing controller includes a driving circuit, a control circuit, and a signal line. The driving circuit controls electricity applied to the electric motor according to a control signal, and generates a rotation-direction signal which indicates a rotation direction of the electric motor by a voltage level. The control circuit outputs the control signal which is generated according to the rotation-direction signal. The rotation-direction signal is transmitted from the driving circuit to the control circuit through the signal line. The driving circuit outputs the rotation-direction signal of high-level during a predetermined period after the control signal is outputted.

Abstract: A control scheme is provided for stopping an internal combustion engine of a hybrid powertrain during ongoing vehicle operation. The method, executed as program code in an article of manufacture comprises the following steps in the sequence set forth. First, engine operation is controlled to stop firing the engine. A damper clutch is controlled to lock rotation of the engine and the electro-mechanical transmission. Torque outputs from the first and second electrical machines are then selectively controlled to reduce engine speed. Torque outputs from the first and second electrical machines are then selectively controlled to stop rotation of the engine substantially near a predetermined crank position.

Abstract: There is provided a control scheme for restarting an internal combustion engine of a hybrid powertrain during ongoing vehicle operation. The method comprises generating a torque output from an electrical machine to rotate the engine, and determining an engine crank torque. The torque output from the electrical machine is selectively controlled based upon the engine crank torque. The engine is fired when rotational speed of the engine exceeds a threshold. An engine torque simulation model accurately determines engine compression pressures in real-time to accommodate changes in engine operating conditions, based upon present engine operating conditions.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel into a combustion chamber of the engine, and an exhaust gas recirculation mechanism for recirculating a portion of exhaust gases from the engine to the combustion chamber. The exhaust gas recirculating mechanism includes an exhaust cooler for cooling the recirculated exhaust gases. A target ignition timing of the fuel injected by the fuel injection valve is calculated. An actual compression ignition timing of the fuel injected by the fuel injection valve is detected. Operation of the exhaust cooler is controlled based on the target ignition timing and the actual compression ignition timing.

Abstract: A valve characteristic control apparatus is provided in an internal combustion engine including a variable valve mechanism that can change at the least, among valve characteristics of an exhaust valve, a closing timing of the exhaust valve, and in which a number of injections of fuel is changed during one engine cycle. The valve characteristic control apparatus sets the closing timing of the exhaust valve to a retard side during an engine warming up operation. When setting to the retard side is performed, if two injections are performed, an exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a dual injection use map. On the other hand, if one injection is performed, the exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a single injection use map.

Abstract: A pulse width signal modifier comprises a fuel injector monitor in communication with an engine fuel injector. A signal modifier is configured to modify a 25% greater pulse width signal output to the fuel injector, wherein the modified pulse width signal is optimized for an E85 fuel blend.

Abstract: The invention relates to an internal combustion engine comprising an inlet tract, leading to the inlet to a cylinder where a gas inlet valve is arranged. A valve drive for the gas inlet valve is provided, by means of which the valve stroke of the gas inlet may be adjusted using an actuator element, which permits differing cams to operate the gas inlet valve. An inductive actuator drive is arranged on the actuator element in which a voltage is induced during a switching process. A first unit is embodied for recognition of whether a switching of the valve stroke has occurred by means of the voltage induced in the inductive actuator drive which is characteristic of the switching process. A second unit is embodied for the control of at least one further actuator body depending on whether a switching of the valve is recognized in the first switching unit.

Abstract: A circuit and method for correcting signal timing. The circuit and method generate a first signal with a first phase that is out of phase with a periodic object, generate a voltage signal that corresponds to the frequency of the first signal and generate a second signal based on the first signal and the voltage signal, the second signal having a second phase that is substantially in phase with the periodic object.

Abstract: A method of controlling ignition timing of an engine. In the control method, final ignition timing for performing ignition is calculated by adding a variation component to a set ignition timing. According to the final ignition timing, an indicated average effective pressure of an in-cylinder pressure detected when ignition is performed is calculated. An ignition timing characteristic curve indicating the correlation between the indicated average effective pressure and the variation component is estimated and optimal ignition timing is calculated from the characteristic curve. Feedback control for converging the set ignition timing to the optimal ignition timing is then performed. Consequently, the ignition timing is controlled to an optimal ignition timing corresponding to a current operational state of the engine.

Abstract: A valve characteristic control apparatus is provided in an internal combustion engine including a variable valve mechanism that can change at the least, among valve characteristics of an exhaust valve, a closing timing of the exhaust valve, and in which a number of injections of fuel is changed during one engine cycle. The valve characteristic control apparatus sets the closing timing of the exhaust valve to a retard side during an engine warming up operation. When setting to the retard side is performed, if two injections are performed, an exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a dual injection use map. On the other hand, if one injection is performed, the exhaust side target displacement angle VTTex of the exhaust valve is calculated based on a single injection use map.

Abstract: A method of analyzing variations in an indicator of the behavior of a mechanism, in which noise is extracted, and any discontinuities from an indicator in order to obtain a trend, variations in the trend are compared with one or more reference values; and a fault of the mechanism is indicated as a function of the result of the comparison. Any outlier data in the indicated data are search for and subtracted, and any edge data are extracted from the data obtained from the search operation.

Abstract: A method to control injection timing for an internal combustion engine having a plurality of injectors in at least a cylinder, the method comprising of boosting intake air delivered to the engine, directly injecting a fuel to at least a cylinder of an internal combustion engine, adjusting each of a timing and number of direct injections for a cylinder cycle as an alcohol amount in the fuel varies, where said adjusting includes advancing direct injection timing relative to intake valve timing as said alcohol amount increases.

Abstract: A fuel injection device (fuel supply system) of a common rail type fuel injection system for an engine includes a pressure sensor disposed in a fuel inlet of an injector for measuring a fuel pressure at a position where the sensor is disposed and an ECU for sensing various kinds of pressure fluctuations associated with the injection including a pressure leak due to an injection operation of the injector and waving characteristics due to actual injection thereof based on sensor outputs from the pressure sensor. The ECU serially obtains the sensor outputs from the pressure sensor at intervals of 20 ?sec.

Abstract: A control device is provided that controls the injection quantity and injection timing of fuel injected into the cylinder of a diesel engine, in which are provided two control modes of: a normal injection mode in which the injection quantity and injection timing are controlled so that the injected fuel ignites near compression top dead center during an injection period; and a premixed injection mode in which the injection quantity and injection timing are controlled so that fuel injection is completed before compression top dead center and the injected fuel ignites near compression top dead center after a premixing period, and target values of control parameters (pilot injection timing, and the like) are set in advance separately for each control mode, the control device comprising change means for gradually changing target values V1 of one control mode into the target values V2 of the other control mode when switching from one control mode to the other control mode.

Abstract: A control method for an actuator (1-4) of an injector of a fuel injection system in an internal combustion engine has the following steps: specification of a target value (SOISOLL) for the start of the injection; electric control of the actuator (1-4) at a specific trigger time (tTRIGGER) with a specific actuator energy (E); detection of an actual value (SOI1IST, SOI2 IST, SOI3 IST, SOI4 IST ) at the start of the injection; determination of the deviation between the target and actual values (DeltaSOI1, DeltaSOI2 , DeltaSOI3 , DeltaSOI4) at the start of the injection; and adjustment of the actuator energy (E) in accordance with the deviation between the target and actual values (DeltaSOI1 , DeltaSOI2 , DeltaSOI3 , DeltaSOI4) at the start of the injection to control the start of the injection.

Abstract: A method for operating an internal combustion engine, particularly of a motor vehicle. The internal combustion engine has a combustion chamber and an injection valve by which fuel is able to be supplied to the combustion chamber, directly or via an intake manifold. In the method, a maximum combustion chamber pressure and a signal for a start of the injection of fuel is determined, and the signal for the start of injection is influenced as a function of the maximum combustion chamber pressure. A signal for an injection duration of fuel is determined and influenced as a function of the maximum combustion chamber pressure.

Abstract: A glow plug is provided in a combustion chamber of a diesel engine. An ECU diagnoses existence or nonexistence of a disconnection abnormality of the glow plug through a controller. When there is an abnormality in the glow plug, processing for cutting fuel supply of an abnormal cylinder, processing for increasing fuel injection quantity of a normal cylinder, processing for delaying injection timing of the abnormal cylinder, or processing for delaying valve timing of an intake valve of the abnormal cylinder is performed. Thus, suitable startability of the engine can be ensured even when the abnormality occurs in the glow plug.

Abstract: An object of the present invention is to provide a fuel injection control technique which maximizes engine power according to fuel evaporation characteristics. The fuel injection timing in the intake stroke is delayed according as a physical quantity affecting the fuel evaporation time changes such that the fuel evaporation time decreases. Further, the fuel injection timing when a physical quantity affecting the fuel evaporation time is such that the fuel evaporation time decreases is set closer to the end of the intake stroke than the fuel injection timing when the physical quantity is such that the fuel evaporation time increases. The fuel injection timing is controlled so as to maximize engine power according to fuel evaporation times.

Abstract: A method is provided for a virtual sensor system. The method may include obtaining data records associated with a plurality of input parameters and at least one output parameter and adjusting values of the input parameters based on autocorrelation of respective input parameters. The method may also include reconfiguring the input parameters based on cross-correlation of respective input parameters relative to the output parameter and establishing a first virtual sensor process model indicative of interrelationships between the adjusted and reconfigured input parameters and the output parameter.

Abstract: A fuel injection system for a direct fuel injection engine includes an injection mode module. The injection mode module selects a fuel injection mode to be one of a single injection mode and a dual injection mode. A fuel injection command module transitions between the single and dual injection modes by varying the timing of fuel injection events relative to a crankshaft position.

Abstract: An article of manufacture and method are provided to determine pressure in an unfired cylinder of an internal combustion engine. The cylinder comprises a variable volume combustion chamber defined by a piston reciprocating within a cylinder between top-dead center and bottom-dead center points and an intake valve and an exhaust valve controlled during repetitive, sequential exhaust, intake, compression and expansion strokes of said piston. The code is executed to determine volume of the combustion chamber, and determine positions of the intake and exhaust valves. A parametric value for cylinder pressure is determined at each valve transition. Cylinder pressure is estimated based upon the combustion chamber volume, positions of the intake and exhaust valves, and the cylinder pressure at the most recently occurring valve transition.

Abstract: The invention relates to an internal combustion engine which is provided with a manifold from which an intake tube extends to an intake of a cylinder of the internal combustion engine, with a gas inlet valve, disposed at the intake of the cylinder, an intermittent charge valve, disposed upstream of the gas inlet valve in the intake tube and releasing or closing the intake tube subject to a switching position of the intake tube, and in injection valve for metering fuel. The temporal position of the duration of injection of the fuel is adjusted subject to a point in time at which the switching position of the intermittent charge valve is changed. In this manner, it can be ensured that the air has a high velocity of flow during injection, thereby obtaining a good mixture preparation in a simple manner.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel into a combustion chamber of the engine and burning the injected fuel by compression ignition. A fuel injection control parameter for controlling at least one fuel injection valve is changed. A combustion state of the engine is then detected. A cetane number of the fuel is then estimated based on the changed fuel injection control parameter and the detected combustion state.

Abstract: An engine control device and method that prevents fuel injection quantity from becoming unstable due to a rapid change of a correction quantity even in a predetermined operation state such as acceleration time and thus stabilizes an air-fuel ratio. Under a predetermined operating state, even when feedback control of oxygen in exhaust gas is stopped, a correction quantity immediately before the predetermined operating state is held by a correction quantity storage part and the correction of the fuel injection time is performed based on the correction quantity.

Abstract: A control system for an internal combustion engine having at least one fuel injection valve for injecting fuel to an intake pipe or a combustion chamber of the engine. Intake gas state parameters indicative of a state of the intake gases supplied to the engine are detected. Demand values of the intake gas state parameters are calculated according to operating condition parameters indicative of an operating condition of the engine. The intake gas state is controlled so that the intake gas state parameters coincide with the demand values. A control value is then calculated according to the operating condition parameters and deviations of the intake gas state parameters from the demand values. Accordingly, an amount of fuel injected by the at least one fuel injection valve is controlled according to the control value.

Abstract: A system for communicating information between a valve controller and an engine controller is presented. The system is designed to improve the timing of data transferred between two controllers.

Abstract: In a variable valve unit provided with a variable valve mechanism that varies opening characteristics of an engine valve by rotary motion of a control shaft, an actuator that generates a rotary motion of the control shaft, a stopper restricting the rotary motion of the control shaft, and an angle sensor capable of outputting signals corresponding to angle positions of the control shaft, when the signal of the angle sensor at an angle position where the rotation of the control shaft is restricted by the stopper are learned, the actuator is controlled such that the control shaft is pressed against the stopper, after which drive torque of the actuator is reduced and with the drive torque reduced, signals of the then-angle sensor are stored.

Abstract: A fuel injection control apparatus and method for an internal combustion engine are provided for appropriately calculating fuel injection times for an in-cylinder fuel injection valve and a port fuel injection valve, thereby accurately controlling the amounts of fuel supplied to the internal combustion engine from the in-cylinder fuel injection valve and the port fuel injection valve, respectively. The fuel injection control apparatus calculates an in-cylinder fuel injection amount which should be injected by the in-cylinder fuel injection valve, and calculates an in-cylinder fuel injection time which is a valve opening time of the in-cylinder fuel injection valve in accordance with the calculated in-cylinder fuel injection amount and an acquired cylinder internal pressure.

Abstract: This disclosure teaches a method of controlling a direct injection internal combustion engine and predicting the behaviour of a direct injection internal combustion engine. An estimation of initial cylinder pressure, air flow and EGR flow (if applicable) is used to establish a system that provides engine behaviour by integrating an injection module, combustion module and engine control module to provide data indicative of engine behaviour such as brake torque and power, air flow, EGR flow, cylinder pressure, brake specific fuel consumption, start of combustion, heat release rate, turbo-charger speed and other variables. These values can then be used to adjust commanded variables such as start of injection, commanded pulse width, rail pressure to meet operator demand. Also the output data can be used as a tool to determine how a conceptualised engine design will behave.

Abstract: A system for controlling variable valve includes a crank angle sensor detecting an angle of a crankshaft, an engine control unit (ECU) (ECU) outputting a control signal to the intake and exhaust valves by receiving a sensing signal from the crank angle sensor, a control portion transmitting the signal input from the engine control unit (ECU), a first valve comprising a first actuator controlling the intake valve and a second valve comprising a second actuator controlling the exhaust valve wherein each actuator receives the signal from the control portion, a pressure supply unit supplying pressure to the first and second valves, and first and second sensors detecting positions of the actuators, wherein the control portion compensates the operation error of actuators by receiving the feedback signal from the first and second sensors. By controlling variable valve, the intake and exhaust valves may be precisely controlled and fuel consumption can be improved.

Abstract: A system for operating an internal combustion engine with electromechanical valves, the system comprising of a cylinder with at least an electromechanical intake valve and at least an mechanically actuated exhaust valve that can be controlled to adjust valve opening and closing events relative to a crankshaft location; and a controller to adjust said electromechanical valve timing and said mechanically actuated valve timing.

Abstract: According to the invention, noise of an internal combustion engine is reduced by dynamically correcting the moment of injection when the engine is in the transient mode.

Abstract: A fuel injection control apparatus of an internal combustion engine is disclosed. This apparatus is provided with a crank angle detector that includes a signal rotor having a number of tooth portions and a toothless portion. The crank angle detector outputs a first signal corresponding to each tooth portion and a second signal corresponding to the toothless portion. A control computer selectively carries out a first calculation process for calculating the timing of fuel injection using the first signal and a second calculation process for calculating the timing of fuel injection using the second signal. When carrying out the second calculation process, the control computer calculates the timing of fuel injection using the length of time gained by dividing the length of time gained through detection of the toothless portion by the number of tooth portions which can be aligned in the toothless portion.

Abstract: A rotary shaft is formed with an external screw thread; a movable nut is engaged with the rotary shaft, and arranged to move axially in accordance with rotation of the rotary shaft; and a link member is swingably connected with the movable nut to transmit motion from the movable nut. The link member includes first and second side portions and a connecting portion connecting the first and second side portions and forming a depressed portion in which the rotary shaft is received when the link member is in a predetermined leaning posture.

Abstract: An engine idle speed control system for regulating an idle speed of an internal combustion engine includes a first module that determines an indicated torque of the engine based on a current spark timing and a second module that determines a desired indicated torque based on the indicated torque. A third module determines a new spark timing based on the desired indicated torque and a fourth module that regulates operation of the engine based on the new spark timing.

Abstract: In a system for controlling an engine having an input u, there are provided with applying means (vibration signal) for applying a component p that changes at a predetermined cycle to the plant, a Washout Filter for calculating a parameter h based on an output y of the plant, a finite interval integrator for integrating a value j obtained by multiplying the calculated parameter h by the applied component p in an interval of integral multiple of a cycle of the component p, and an infinite interval integrator, etc. for calculating the input u based on the integrated value g obtained by the integration. Owing to this configuration, it becomes possible to provide a system that can optimize the output y, while preventing the resonance of the control system.

Abstract: A method of operating an internal combustion engine in a motor vehicle has the steps of determining angular positions of a crankshaft and a camshaft from signals of two detecting devices, monitoring a relative angular position of one of the shafts relative to the other of the shafts, and, depending on whether a change of the determined actual relative position is located outside the tolerance region, releasing an action, and also a computer program, a storage medium, a control and/or regulating unit, and an internal combustion engine with the use of inventive method are proposed.

Abstract: An engine control system and an engine control method are disclosed wherein a combustible component quantity of intake air, reflecting combustible components in a crankcase of an engine, is calculated on the basis of a deviation between basic injection quantity for a target rotational speed to be attained and an actual injection quantity during operation to perform idling stabilizing control. A ratio of the combustible components mixed to engine oil is calculated on the basis of the combustible component quantity of intake air and a temperature of engine oil. During a status of the engine with a given temperature of engine oil and the mixing ratio of the combustible components in engine oil, a fuel injection affect eliminating operation is executed.