Abstract: A control system for adjusting levels of emissions exiting an engine includes a NOx sensor that generates a NOx signal in response to oxides of nitrogen (NOx) in an exhaust gas and a control module that communicates with the cam phaser. The rotational position of the cam phaser controls an actuation time when the camshaft opens the exhaust valve during rotation of the camshaft. The control module further receives the NOx signal, and calculates a NOx level of the exhaust gas based on the NOx signal. The control module compares the NOx level to a predetermined threshold range and adjusts the cam phaser to achieve a rotational position that releases a desired level of NOx from the engine when the NOx level exceeds the predetermined threshold range. The control module further stores the rotational position in a storage device when the NOx level is within the predetermined threshold range.

Abstract: To quickly suppress a detected decrease in engine speed in a direct injection internal combustion engine (10), a fuel injection quantity is increased by performing a supplementary fuel injection in addition to a normal fuel injection.

Abstract: A diagnostic apparatus for an internal combustion engine, comprising an adjusting device for adjusting a burning condition, a correction device for estimating or detecting an input or an output to and from the internal combustion engine so as to correct at least one of a throttle opening degree, a fuel injection pulse width, a fuel injection timing, an ignition timing and an exhaust gas recirculation quantity, a recording device for recoding a controlled correction value from the correction device at every predetermined time, and a fuel consumption evaluation means for evaluating a fuel consumption of the engine, being based upon the recorded data or log data as to the recorded data, wherein a deterioration of fuel consumption caused by an abnormality of the engine can been soon detected with no affection by an operating condition of the engine and unevenness of component parts.

Abstract: A method of controlling a valve of a cam phaser of an internal combustion engine includes determining a delta duty cycle from a position error and a rate of change of error (error dot). A fuzzy gain value is calculated from the delta duty cycle and a correction term. A duty cycle is calculated from an integral gain value and the fuzzy gain value. The duty cycle is then used to control the valve of the cam phaser.

Abstract: An abnormality diagnosis system 100 includes a VVT controller 110, an adjustable valve mechanism 120, a cam angle sensor 130, a model computation module 140, an abnormality detection module 150, and an alarm lamp 160. The adjusable valve mechanism 120 advances or delays a phase angle of an intake cam shaft relative to a crankshaft, thereby varying an open-close timing of a valve. The model computation module 140 computes a physical behavior of the adjustable valve mechanism 120 according to a physical model, in response to a control signal input from the VVT controller 110. The abnormality detection module 150 determines whether the adjustable valve mechanism 120 is abnormal or normal, based on a difference between a theoretical value of phase angle calculated according to the physical model and an observed value of phase angle measured with the cam angle sensor 130. The arrangement of the invention ensures highly accurate abnormality diagnosis of the adjustable valve mechanism 120.

Abstract: A method and an apparatus for predicting intake manifold pressure are presented, to compensate for a large lag or a large time delay without producing an overshot or discontinuous behaviors of a predicted value. The method comprises the step of obtaining a difference of values of a variable to be predicted and a difference of values of another variable ahead of the variable to be predicted. The method further comprises the step of filtering the differences with adaptive filters. The method further comprises the step of obtaining a predicted difference of values of the variable to be predicted, through algorithm of estimation with fuzzy reasoning. The method further comprises the step of adding the predicted difference of values of the variable to be predicted, to a current value of the variable to be predicted, to obtain a predicted value of the variable to be predicted.

Abstract: A humidity based control system for an internal combustion engine includes a calculation module and a calibration module. The calculation module determines a humidity of air used in a combustion process of the internal combustion engine. The control module selectively controls spark timing and exhaust dilution in the internal combustion engine based on the humidity.

Abstract: A valve timing controller has the drive circuit which performs a feedback control of the energization to the electric motor based on the target rotation speed and the actual rotation speed of the electric motor, and rotates the electric motor to the target rotation direction. An invalid switch part of the drive circuit suspends the feedback control at the time of change of the target rotation direction.

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 1 of an internal combustion engine 3, which variably controls the amount of intake air drawn into cylinders #1 to #4 as desired via a variable intake valve actuation assembly 40 includes an ECU 2. The ECU 2 calculates a cylinder intake air amount Gcyl and a target intake air amount Gcyl_cmd (step 16), identifies, based on a controlled object model [equation (2)], a vector ?s of all model parameters of the controlled object model with an identification algorithm [equations (8) to (13)], calculates a target auxiliary intake cam phase ?msi_cmd based on the vector ?s with a sliding mode control algorithm [equations (15) to (21)] (step 80), and controls the variable intake valve actuation assembly 40 according to the target auxiliary intake cam phase ?msi_cmd.

Abstract: A method is shown for operating an internal combustion engine having a combustion chamber with a piston, the internal combustion engine capable of injecting fuel into the combustion chamber multiple times during a cycle, the method comprising: performing a first fuel injection after approximately ?25 crank angle degrees after top dead center and before approximately 15 crank angle degrees after top dead center; and performing a second fuel injection at least 5 degrees after the start of the first fuel injection and less than approximately 25 crank angle degrees after the start of the first fuel injection.

Abstract: The invention relates to a method for controlling the operation of a cylinder group for an internal combustion engine comprising an intake valve, an exhaust valve, handling members for controlling the opening of valves according to the predetermined conditions of the engine operation for selectively opening or closing said intake and exhaust valves, wherein the closing of the intake and exhaust valves is carried out at two distinct adapted times: for the intake valves, in the middle of a time extending between the theoretical intake valve closing timing of one cylinder and the intake valve opening timing of the other cylinder; for the exhaust valve of the cylinders, in the middle of a time extending between the exhaust valve theoretical closing timing of one cylinder and the exhaust valve opening timing of the other cylinder.

Abstract: An engine control system that having an exhaust gas recirculation (EGR) valve includes a first module that determines an EGR error and a second module that calculates a fuel injection timing based on the EGR error. Operation of an engine is regulated based on the fuel injection timing to reduce emissions during transient operation of the engine.

Abstract: A fuel control system for a cylinder direct injection internal combustion engine. A predetermined portion of the fuel spray is appropriately ignited regardless of the correction of the ignition timing, thereby always securing stable, satisfactory combustion. In the case where the ignition timing is corrected, the fuel injection timing is corrected in accordance with the ignition timing correction amount. The fuel injection timing is corrected also with the change in the internal cylinder pressure and the fuel injection velocity taking the intake pipe pressure and the fuel pressure into account, thereby maintaining the required ignition point of the fuel spray.

Abstract: In a method of controlling an internal combustion engine having a common rail fuel injection system including individual fuel storage chambers, wherein the pressure pattern of the fuel supplied to each injector can be determined and actual and virtual fuel injection ends and fuel injection begins are determined, the deviations from the desired fuel injection ends and from the fuel injection begins are calculated and the injectors are evaluated on the basis of the deviations and further control of the internal combustion engine is based on an evaluation of the fuel injectors.

Abstract: A controller for controlling the operation of a fuel injector having a piezoelectric actuator which is operable by the application of a voltage drive profile across the actuator, the controller comprising inputs for receiving data relating to one or more engine parameters and a processor for determining a voltage drive profile for controlling the actuator in dependence upon the one or more engine parameters. The voltage drive profile is arranged to comprise an activating voltage component to initiate an injection event and a deactivating voltage component to terminate the injection event, the activating and deactivating voltage components being separated by a time interval TON. The controller further receives outputs for outputting the voltage drive profile as determined by the processor to the actuator, wherein the processor is arranged to set the time interval TON greater than or equal to a predetermined pressure wave time period (TP) of a pressure wave cycle within the injector.

Abstract: A control system for an internal combustion engine having a fuel injector located in a combustion chamber of the engine for injecting fuel into the combustion chamber. The fuel injection timing stored in a fuel injection timing map is retrieved according to the detected engine operating condition to determine the fuel injection timing. An actual ignition timing of the fuel injected into the combustion chamber is detected. An ignition delay of the actual ignition timing with respect to the target ignition timing, which is set according to the engine operating condition and a fuel injection timing correction amount, is calculated according to the calculated ignition delay. The fuel injection timing is corrected with the fuel injection timing correction amount, and the fuel injection is executed according to the corrected fuel injection timing.

Abstract: Tooth portions are formed at unit angles on a rotor connected with a crankshaft of an internal combustion engine. A toothless portion is formed on the rotor by irregularly changing the regular arrangement of the tooth portions. A controller of the engine estimates times necessary for rotation of unit angles of an arbitrary angular range of 50° CA including the toothless portion and a pair of tooth portions adjacent to the toothless portion by using times necessary for rotation of unit angles of a different angular range of 50° CA distant from the arbitrary angular range by 180° CA. Thus, the controller can maintain high controllability of the engine even when there occurs a range where the time necessary for the rotation of the crankshaft is not sensed appropriately.

Abstract: Apparatuses and methods for determining a desired charge density for an engine. A first characteristic indicative of an engine speed of the engine is determined. A second characteristic indicative of a load on the engine is determined. A value indicative of a desired charge density of a combustion mixture for the engine is determined as a function of the first and second characteristics.

Abstract: This invention detects the crank angle location where combustion switches from premixed to diffusion, referred to as the transition index, and uses that location to define integration limits that measure the portions of heat released during the combustion process that occur during the premixed and diffusion phases. Those integrated premixed and diffusion values are used to develop a metric referred to as the combustion index. The combustion index is defined as the integrated diffusion contribution divided by the integrated premixed contribution. As the EGR rate is increased enough to enter the low temperature combustion regime, PM emissions decrease because more of the combustion process is occurring over the premixed portion of the heat release rate profile and the diffusion portion has been significantly reduced. This information is used to detect when the engine is or is not operating in a low temperature combustion mode and provides that feedback to an engine control algorithm.

Abstract: In a method of controlling an internal combustion engine with a common rail fuel injection system including individual fuel storage chambers for the supply of fuel to the various cylinders of the internal combustion engine, a fuel pressure (pE(i)) is determined during a measuring interval (MESS) and is stored, the existence of a significant change in the fuel pressure is determined as an injection begin (SB=f(pE(i), Phi)) or an injection end (SE=f(pE(i)), Phi), a virtual injection begin is calculated by way of a mathematical function (FKT) depending on the injection end (SE), and the virtual injection begin (SBv) is used as the actual injection begin (SB) for the subsequent control of the internal combustion engine.

Abstract: In a distributed control system, a first electronic control unit sends trigger information to a second electronic control unit. The trigger information includes a timing that triggers the second electronic unit to obtain second sensor information from a second sensor. The second electronic control unit is designed to receive the trigger information, and obtain, at the timing of the trigger information, the second sensor information from the second sensor. The second electronic unit is configured to send, to the first electronic control unit, the obtained second sensor information.

Abstract: A method and a device for controlling an internal combustion engine are provided, in which method and device a deviation value is determined based on the comparison of a variable characterizing the combustion process in at least one cylinder with a corresponding setpoint value for this variable. Based on the determined deviation value, a first manipulated variable of a first actuator for influencing the start of activation is adjusted. Furthermore, based on the first manipulated variable, a second manipulated variable of a second actuator for influencing the air mass is adjusted.

Abstract: A method for controlling an injection system of an internal combustion engine having at least one injector, the fuel metering being divided into a first partial injection and at least one second partial injection, and a control signal which determines the fuel quantity to be injected with the aid of the at least one injector being corrected as a function of a pressure wave influencing the at least two partial injections, the pressure wave correction being performed on the basis of a periodic model which models the quantity wave as a sum of periodic functions.

Abstract: An engine control apparatus for a multi-cylinder compression ignition internal combustion engine includes a combustion status sensor and a controller. The combustion status sensor is installed in a selected one of cylinders of the engine. The controller works to sample an output from the combustion status sensor to determine a combustion status parameter and determine injection timings so as to bring the combustion status parameter into agreement with a target value. The controller also corrects the injection timing for at least one of the cylinders in which the combustion status sensor is not installed so that a combustion status parameter of the at least one of the cylinders lies on an advanced side of that of the one of the cylinders in which the combustion status sensor is installed, thereby avoiding the deterioration of quality of combustion of the fuel arising from a shift of the time of the ignition in the retarded direction from a desired time point.

Abstract: A valve controller includes a detector detecting a shutdown command signal to shutdown an engine, a driving circuit for driving a motor, and a power source controller. The power source controller turns on the driving circuit until the predetermined period has passed since the shutdown command signal is detected. Thus, the valve controller adjusts the valve opening/closing character in such a manner as to be suitable to an engine condition.

Abstract: A method for diagnosing malfunctions of switching valve lifters includes sensing variations in pressure of trapped oil in a drive chamber of a hydraulic camshaft drive, such as a cam phaser, comparing peak oil pressure readings in the drive chamber resulting from the increased torque of opening the valves of various cylinders of an engine and identifying cylinders having lower than normal valve opening pressure readings, indicating failure of an associated valve lifter to properly actuate a valve of the cylinder. Apparatus for indicating such malfunctions could include a cam phaser with pressure chamber, a pressure sensor connected to indicate pressure variations in the chamber; and a pressure indicator connected to the sensor and adapted to indicate actual pressure variations for comparison with normal variations to identify low pressure peaks indicating malfunction of a switching lifter. A computer could be used to receive and act upon the malfunction indications.

Abstract: A control device executes an overlap injection operation, in which one of the plurality of injectors is energized first to inject fuel, and a next one of the plurality of injectors is energized to inject fuel after starting of the energization of the one of the plurality of injectors while the one of the plurality of injectors is still kept energized. The control device corrects an energization period of the next one of the injectors by lengthening the energization period of the next one of the injectors in comparison to a normal energization period of the next one of the injectors, which is set for a non-overlap injection operation of the next one of the plurality of injectors.

Abstract: A device and a method for controlling an internal combustion engine are provided, in which a first actuating variable of at least one first actuating element is adapted on the basis of a comparison between a first cylinder-specific variable characterizing the combustion process in at least one cylinder and a setpoint value for this variable. On the basis of at least one second variable, at least one deviation value for at least one additional cylinder is determined. Based on this deviation value, a second actuating variable of a second actuating element is adapted.

Abstract: An engine control apparatus is disclosed for determining crankshaft position and engine phase of an internal combustion engine through monitoring intake air pressure fluctuations. The opening of the intake valve is mechanically linked to the crankshaft position of an engine. When the intake valve opens it creates air pressure fluctuations in the air induction system of the engine. The control apparatus is configured to determine intake air pressure fluctuations indicative of an intake air event and thus a particular crankshaft position, and their corresponding period of the engine cycle. The controller then uses this information to determine crankshaft speed and position for the purpose of fuel injection and ignition timing of the internal combustion engine. Engine phase is also determined on four-stroke engines. The engine may also include a crankshaft position sensor in combination with monitoring intake air pressure fluctuations to increase resolution in determination of crankshaft position.

Abstract: To operate a steplessly adjustable camshaft control device, particularly reliably and safely, an adaptation of the camshaft and the crankshaft is performed so that a phase angle (actual value) of the camshaft to the crankshaft is determined, the phase angle is monitored while operating the internal combustion engine and the camshaft control device is controlled as a function of a variable setpoint value so that the phase angle is equivalent to the setpoint value.

Abstract: A system and method for controlling electromechanical valves operating in an engine is presented. According to the method, armature levitation is strategically used during a cycle of a cylinder. The method can reduce fuel consumption and power supply requirements, at least under some conditions.

Abstract: A device and a method for controlling an internal combustion engine, in which, based on a signal that characterizes the vibrations of an internal combustion engine, at least one feature is determined and used to regulate and/or control operating parameters of the internal combustion engine. In order to generate the feature the signal of a sensor is filtered. Filtering selects low-frequency components of the signal.

Abstract: A control unit calculates a quantity of air that is taken into an engine from an output current from an air flow meter that is located downstream from a throttle valve. The control unit then determines the quantity of fuel to be injected for this quantity of air. The control unit determines a rise in the air intake as being when the quantity of air is on an increasing trend and has exceeded a predetermined threshold value. In contrast, the control unit determines a fall in the air intake as being when the quantity of air is on a decreasing trend and has exceeded a predetermined threshold value. An injection of fuel starts from a rise in the air intake and is ended at an earlier timing than the end of the air intake.

Abstract: A diesel engine (10) operates by alternative diesel combustion. Formation of fuel and charge air mixtures is controlled by processing a particular set of values for certain input data according to a predictor algorithm model (50) to develop data values for predicted time of auto-ignition and resulting torque, and also develop data values for control of fuel and air that will produce the predicted time of auto-ignition and resulting torque. The data values developed by the predictor algorithm and data values for at least some of the input data are processed according to a control algorithm (52) that compensates for any disturbance introduced into any of the data values for at least some of the input data being processed by the control algorithm. This causes the systems to be controlled by compensated data values that produce predicted time of auto-ignition and resulting torque in the presence of any such disturbance.

Abstract: A method and system to avoid collision of piston and engine valves is provided. This facilitates use of a fully flexible variable valve actuation system over its operating range, without arbitrary constraints. Included is actuation control of the engine valve, determination of a crank angle at which to initiate engine valve opening, and determination of a desired valve lift, and, duration of valve open time. Opening profile for the engine valve is estimated. A first and a second crank angle are calculated, based upon the estimated opening profile. The crank angle to initiate engine valve opening is determined by adding a safety margin to the second crank angle. The method determines a maximum valve lift, given the duration of valve open time and an engine valve opening crank angle, and a minimum duration of valve open time, given a valve lift and an engine valve opening crank angle.

Abstract: Disclosed herein are methods of cranking and/or operating an engine that eliminates the need for use of a cam sensor. The methods implemented with internal combustion engine comprising a plurality of cylinders whose firing sequence occurs over two revolutions of a crankshaft with a first set of cylinders comprising a power stroke during the first crankshaft revolution and a second set of cylinders comprising the power stroke of a second crankshaft revolution. The methods involve manipulating fuel injection command signals to occur out of their proper sequence, monitoring and engine indicator responsive to firing and non-firing of cylinders, and identifying correct engine phase based on fluctuations in the engine indicator. Also disclosed herein are software product embodiments comprising program code modules that cause a engine control unit to manipulate the generation of fuel injection command signals to take place outside their correct sequence.

Abstract: A variable valve mechanism is installed to change the operating angle and lift amount of an intake valve in accordance with the rotation position of a control shaft. A worm wheel is secured to the control shaft. The worm wheel is coupled to a motor actuator via a worm gear. The motor actuator is controlled during a normal operation so that the rotation position of the control shaft changes within a normal rotation range. A low-end stopper and high-end stopper are installed outside the normal rotation range to mechanically restrict the rotation of the control shaft.

Abstract: A control apparatus for an internal combustion engine includes a crankshaft, a camshaft for actuating an intake valve of the engine, a crank position sensor that outputs a crank signal every time the crankshaft rotates 10° of crank angle, an electric motor that is coupled to the camshaft, and an engine control computer that, based on the crank signal, controls the engine every time the crankshaft rotates 30° of crank angle. The motor includes a rotor and three rotation sensors. Each sensor outputs a signal corresponding to induced voltage generated by rotation of the rotor. The computer controls the rotating motor based on the signals from the rotation sensors. When the crank position sensor malfunctions, the computer controls the engine every time the crankshaft rotates 30° of crank angle based not on the crank signal but on a rotation pulse train generated based on the signals from the rotation sensors.

Abstract: A system comprising of an engine having a first group of cylinders and a second group of cylinders, a first variable valve system in said first group, a second variable valve system in said second group, and a controller for determining degradation of operation of at least one of said first and second variable valve systems, said controller determining said degradation in response to controller errors of said valves and differences between operation of said first and second valve systems.

Abstract: A system and method for controlling electromechanical valves operating in an engine is presented. According to the method, armature levitation position may be changed to accommodate varying rates of valve stem growth. The method may reduce valve noise during a wide range of engine operating conditions.

Abstract: A signal modifying device, user interface, and method of modifying a signal. The signal modifying device includes a processor, a first input coupled to the processor and an output coupled to the processor. Instructions are stored within the processor that, when executed by the processor, cause the processor to provide a signal incident at the output that corresponds to a signal incident at the input.

Abstract: A control apparatus for an internal combustion engine provided with a fuel supply mechanism capable of adjusting a fuel supply amount includes a flow rate sensor that detects an intake air flow rate that represents a flow rate of air admitted into a combustion chamber of the internal combustion engine, a pressure sensor that detects a pressure of the air admitted into the combustion chamber of the internal combustion engine, a characteristic change estimation unit that estimates a characteristic change of the internal combustion engine in accordance with the intake air flow rate detected by the flow rate sensor and the intake air pressure detected by the pressure sensor, and a fuel supply mechanism control unit that controls the fuel supply mechanism. The fuel supply mechanism control unit controls the fuel supply mechanism such that the characteristic change in the internal combustion engine is compensated in accordance with an estimation performed by the characteristic change estimation unit.

Abstract: A method for correcting the injection duration of injections is based on pressure fluctuations of preceding injections. The injection duration is determined on the basis of a mapping value and of a correction value. The mapping value is read out from a mapping according to the fuel pressure and according to the amount of fuel to be injected. The correction value is calculated according to the time interval between the subsequent injection and at least one latter injection. This enables a precise determination of the injection duration and thus a precise metering of the desired amount of fuel.

Abstract: A method for controlling start of a compression ignition engine having a plurality of cylinders is provided without a cam sensor is provided. Each cylinder includes a respective piston reciprocally movable between respective top and bottom positions along a cylinder longitudinal axis. The method comprises providing a respective fuel delivery assembly for each cylinder. In one embodiment the method further comprises retrieving from memory a set of fuel delivery assembly firing rules and then processing the firing rules so that a firing signal is delivered to each fuel delivery assembly on every crank revolution during a cranking mode of operation. The fuel delivery assembly is arranged to be responsive to any firing signal received during an injection window leading to the top position along the longitudinal axis so as to supply fuel to each cylinder during that injection window.

Abstract: An arrangement for adjusting the angle of rotation of a camshaft (5) relative to a crankshaft is provided. The arrangement requires many components, which partially also require different operational conditions. The new arrangement is structured in a modular fashion, so that the components of the arrangement are no longer arranged inside a common housing, but rather are separately constructed according to their function and/or operational conditions, for example, they are used jointly by other control or adjustment devices. It is particularly advantageous that such arrangements can be produced in a reduced size and in a more cost effective manner and can be used for adjusting the valve play of internal combustion engines.

Abstract: A piston engine and a method for controlling a diesel-type piston engine including at least one combustion chamber formed by a cylinder. A movably arranged piston is provided in each cylinder is connected to a crankshaft. An injection device is provided that is configured to inject fuel directly into the combustion chamber. Thermal efficiency of the internal combustion engine can be increased while at the same time requirements relating to nitrogen oxide and soot particle emissions can also be maintained.

Abstract: A method for processing an accelerometer data set generated from an operating internal combustion engine is disclosed. The processed accelerometer data is cepstrally filtered and a heat release trace is pulled from the accelerometer data set. That heat release trace is then used to estimate combustion quality and combustion phasing within the engine and control future combustion events using this information. Misfire and knock sensing is also incorporated into the engine controls. The method provides controls for an engine to allow it to adjust combustion from cycle window to cycle window generally without the need for expensive and less durable direct pressure measurement devices as compared to accelerometers. The resulting fuel injection speed results in the fuel passing through shock waves within the combustion chamber, which, in turn, promotes combustion of the fuel by promoting mixing of the fuel and intake charge within the combustion chamber.

Abstract: A diesel engine (10) wherein both the operating speed of the engine (RPM) and the timing of the fuel injection into the engine (AA) are cooperatively controlled to be responsive to both the temperature and the pressure of the air (30) used for combustion. A controller (44) receives a temperature signal (28), an air pressure signal (36), and a power demand signal (24) and executes control logic to produce a fuel injection control signal (46) and an engine speed control signal (48) for controlling a fuel injection system (16). A control strategy based on engine inlet air temperature and pressure or manifold air density may be useful for variable speed and power applications. For applications with discreet speed and power points, such as a locomotive, a speed and timing control strategy based on ambient temperature and pressure is useful for maximizing power during high altitude and/or high ambient/inlet air temperature operation.

Abstract: A system and method for controlling an internal combustion engine during starting use position sensor information in addition to cylinder combustion information to transition from simultaneous fueling to sequential fueling by selecting a cylinder to receive a first sequential fuel injection. Embodiments include a system and method for controlling a sequentially fueled port injected internal combustion engine that contingently select a cylinder to receive a first sequential fuel injection based on position information indicating that the cylinder received a simultaneous fuel injection during its intake stroke. Engine rotational speed is monitored to detect combustion and determine which cylinder fired first. A first sequential fueling pulse is provided to the contingently selected cylinder unless a preceding cylinder in the firing order fires first.

Abstract: The valve controller is driven by a motor. The valve controller has a control circuit and a driving circuit. The driving circuit drives a motor based on a control signal generated by the control circuit and a rotational position signal generated by a rotational position sensor. The driving circuit generates a rotation number signal representing an actual rotation number of the motor according to the rotational position signal, and transfers the rotation number signal to the control circuit.