Abstract: An engine control apparatus and related control method for an engine are disclosed wherein cylinder discrimination is executed based on a crank signal and a cam signal under a normal signal mode. If a failure occurs in either the crank signal or the cam signal, the cylinder discrimination is executed based on a normal one of the crank signal and the cam signal. A starter device is driven to crank up the engine until judgment is made that the engine enters a running state. A duration time for the starter device to be driven is measured and if the duration time reaches a limit time, the driving state of the starter device is interrupted. When either the crank signal or the cam signal encounters the failure, the limit time is set to a longer time than a preset time for the normal signal mode.

Abstract: A power management device comprises a start management control unit having a starter hold control function for actuating a starter motor and holding the actuation based on an operating signal from a button switch, a first terminating unit for terminating cranking hold when receiving a starter stop instruction signal sent from an engine control device when it is determined that an engine reached a complete explosion, a second terminating unit for terminating cranking hold when it is determined that the engine reached a complete explosion based on an engine revolution signal sent from the engine control device, and a forced terminating unit for forcefully terminating cranking hold when cranking hold cannot be terminated by those terminating units.

Abstract: In a system, a setting unit sets historical information in response to a manual transient operation. The manual transient operation triggers automatic start of the engine. The historical information represents that the manual transient operation has existed. A validation unit has a first identifier uniquely identifying the vehicle. The validation unit carries out validation communications, in at least one of direct and indirect procedures, with a communication device storing therein a second identifier of the vehicle. The communication device is used by a user of the vehicle. The validation communications use the first and second identifiers. The validation unit validates whether the user is certificated based on the validation communication result. An engine starting unit automatically starts the engine when the historical information has been set by the setting unit and when it is determined that the user of the vehicle is certificated.

Abstract: An electric variable valve timing mechanism and a starter are actuated by electricity supplied from a common battery. During an engine starting process, the starter is actuated, and an electronic control unit controls the electric variable valve timing mechanism. The electronic control unit limits the actuation of the electric variable valve timing mechanism on the condition that, during the engine starting process, the voltage value of the battery falls below a predetermined threshold value that degrades the operation of the starter. As a result, the engine is started in a stable manner.

Abstract: A method of performing a first start of an internal combustion engine of a hybrid electro-mechanical vehicle includes activating an auxiliary power module prior to the engine starting to direct power stored in a high voltage battery (used for powering the motor/generator(s) on the hybrid vehicle) through the auxiliary power module at a voltage level of a low voltage battery to assist the low voltage battery in powering a starter motor for starting the internal combustion engine.

Abstract: A hybrid electric vehicle having a brake operated by compressed air, and a system and method for controlling the idling stop of a hybrid electric vehicle in which, when the vehicle idling-stops on a slope having a predetermined angle, the idling stop is allowed only when the pressure of compressed air within an air tank is higher than a predetermined pressure in the state in which the tilt angle of the current slope is less than a predetermined angle, thereby preventing accidents due to the vehicle being pushed forwards or backwards.

Abstract: An electronic control apparatus includes a control circuit and has a power supply holding function whereby when a power switch-off command is received by the apparatus, the supplying of power to the control circuit is continued until it has completed specific processing, during a power supply holding interval. The duration of each such interval is measured and stored in non-volatile memory, and subsequently used for detecting any power supply holding function abnormality, and for ensuring that the specific processing is actually performed, and distinguishing between an abnormality causing premature switch-off and an abnormality causing failure to terminate the supplying of power.

Abstract: An engine starting method includes maintaining a rotation speed of a crankshaft of an engine rotated by a motor at a first rotation speed, supplying fuel to the engine and igniting the fuel while the crankshaft is rotated by the motor at the first rotation speed, determining whether the fuel has been ignited in the engine, and maintaining the rotation speed of the crankshaft rotated at least by the motor at a second rotation speed that is greater than the first rotation speed upon determining that the fuel has been ignited.

Abstract: An engine starting assist system includes an auxiliary ECU having a voltage booster, an engine ECU, a starter relay, and a starter that allows the engine to be started when a current flows through the starter relay. The auxiliary ECU and the engine ECU are powered by a battery and supply currents to the starter relay. When the engine ECU resets the supply of the current to the starter relay because of a voltage drop of the battery during starting of the engine, the auxiliary ECU increases the voltage supplied from the battery using the booster, thereby supplying the current to the starter relay.

Abstract: An engine-starting device for an engine. The device includes a counter that provides a counting value based on an initiation of engine cranking; and a cranking control system that prohibits engine cranking if the counting value of the counter passes a cranking prohibition threshold value.

Abstract: An engine control system includes an ignition switch, a starter switch which operates a starter of an engine after the ignition switch has been turned on, and a voltage increasing circuit which increases a battery voltage to a higher voltage. The engine control system controls the voltage increasing circuit to start to increase a voltage from a battery to the higher voltage upon a timing of turning on the starter switch. Thus, radio noises caused by an operation of the voltage increasing circuit may be avoided from time at which the ignition switch is turned on to time at which the starter switch is turned on (during a quiet time period).

Abstract: A method for engine speed control for an internal combustion engine generating unit (1) is disclosed, whereby a first time point is set when the actual speed (nM(IST)) exceeds a threshold value and a second time point set when the actual speed (nM(IST)) exceeds a start speed. A time span is then calculated from both time points. Depending on said time span, a run-up ramp and the regulation parameters for a speed regulator are selected.

Abstract: An engine cranking system includes an engine, a cranking motor coupled to the engine, a battery, a capacitor and an ignition switch. A first relay is connected between the cranking motor and system ground. A second relay is moveable between at least an open-circuit condition and a closed-circuit position to complete an electrical path connecting the capacitor with the cranking motor. The first relay is connected between the capacitor and the second relay. In one embodiment, a running engine sensory component is coupled between the first relay and system ground. In another embodiment, the engine cranking system includes a running engine sensory component connected to a relay and a control module connected to the relay and the capacitor. In one embodiment, a momentary switch is coupled between the capacitor and the relay.

Abstract: An engine start control apparatus includes a crank angle sensor, and a stroke discrimination device that discriminates which of engine cylinders is in intake or compression strokes in an engine stopped state. A crankshaft is temporarily reverse-rotated in a reverse-rotational direction by way of crankshaft reverse-rotation control until an intake valve becomes shifted from a valve closed state to a valve open state, when cranking the engine for startup under a specific condition where a crankangle of an engine cylinder whose piston stroke is in the intake stroke or in the compression stroke, is within a specified crankangle range from 40 degrees of crankangle before a piston B.D.C. position to 40 degrees of crankangle after the piston B.D.C. position. The crankshaft is rotated in a normal-rotational direction by way of crankshaft normal-rotation control after the intake valve has been shifted to the valve open state.

Abstract: An operation unit is provided with an engine operation box storing a control operation portion controlling an opening degree of a throttle valve and a start switch terminal connected to a start motor; a throttle operating lever for controlling the opening degree from an idle position to a full-open position; and a start switch connecting and disconnecting the start switch terminal, wherein the throttle operating lever has a switch shielding portion which enables to operate the start switch without an interference between the throttle operating lever and an operating portion of the start switch when the throttle operating lever is at an idle position, and disables to operate the start switch by shielding at least a part of the operating portion of the start switch by means of a part of the throttle operating lever when the throttle operating lever is operated to be apart from the idle position.

Abstract: System, especially for a motor vehicle, able, on the one hand, to start up an internal-combustion engine and, on the other hand, to charge an electrical circuit, including a main electrical machine able to operate, on the one hand, as a generator and, on the other hand, as an electric motor, the said electrical machine driving the internal-combustion engine by means of a belt when it is operating in motor mode, the system further including management means which drive the main electrical machine, characterised in that it includes a supplementary starter, as well as means for detecting at least one condition for triggering the activation of the said supplementary starter, and the management means drive the main electrical machine and the starter, according to a particular sequence, when the said condition is detected by the said detection means.

Abstract: A starting device for an internal combustion engine includes a switching control device for controlling a starter motor. At least one power switching module connects the starter motor to a voltage source and is activated via an assigned control line. A control electronics is provided for controlling the at least one power switching module. A release device which records the power flow of the internal combustion engine makes available, as a function of the running of the internal combustion engine, a release signal for the release of the activating switching procedure by the at least one control line. The release device includes a first release switching channel that works independently of the control electronics and a second release switching channel that cooperates with control electronics. These are set up in such a way that an initiation of the activating switching procedure takes place only during the simultaneous release switching setting of the two release switching channels.

Abstract: A trigger circuit for an engine starter relay includes: (a) a switching device for switching an output of the engine starter relay to a reference potential and for activating the engine starter relay as a function of a trigger signal, which is applied to a trigger input of the switching device; (b) a first logic circuit for the logical linking of a first digital signal of a computer device and a second digital signal of an operating device; (c) a second logic circuit for logically linking the output signal of the first logic circuit with the first digital signal; and a storage device for temporarily storing the state at the outputs of the first and second logic circuit, an output of the storage device being connected with the trigger input of the switching device, the activation of an engine starter relay being ensured in the event that the supply voltage at a computer device falls below a specified value with the result of activating a reset signal.

Abstract: An engine start control apparatus has a power generating circuit that generates power by a starting operation of a starter apparatus that starts an engine, an engine starting circuit that is connected to the power generating circuit and to which various devices required to start the engine are connected, and an accessory circuit that is connected to the engine starting circuit and is provided with various devices that are not required to start the engine. In a state in which a supply of power to the accessory circuit is stopped, power is supplied from the power generating circuit side to the engine starting circuit side.

Abstract: The invention provides an operation unit of an engine provided with a throttle operating lever operating a throttle valve of the engine from an idle position to a full-open position, two terminals connected to an inner side of a drive circuit of a start motor, a contact element interposed between the terminals and setting a region between both the terminals to a conduction state or a non-conduction state, and a start switch making the region between the terminals conductive or non-conductive, the operation unit further comprising interlocking means for relatively moving a contact position between at least one terminal of the two terminals and the contact element in correspondence to an operation amount of the throttle operating lever, and the terminals and the contact element being brought into contact with each other only at a time when the throttle operating lever is at an idle position.

Abstract: An engine start control system which includes: a switch for turning on/off power supply to a starter of an engine; a sensor for sensing a crank angle of the engine; an engine status judgment unit which determines whether or not the engine is in a cranking state based on the crank angle sensed by the sensor; and a switch controller by which the switch is controlled to turn off the power supply to the starter, if a predetermined time elapses without the engine status judgment unit judging that the engine is in the cranking state, after the switch has been controlled to turn on the power supply to the starter.

Abstract: A power module is connected to the starter, alternator, and battery for an internal combustion engine. The power module includes one or more capacitors and delay timer. When the ignition switch closes, the battery of the starting system provides current to the starter motor, causing the starter solenoid to close the starter contacts, and bring a starter pinion gear into engagement with a flywheel ring gear. The delay timer does not allow the capacitor to immediately deliver current to the starter motor, but implements a short delay before the capacitor's current is released to the starter motor. This short delay increases the chance for full engagement between the starter pinion and the flywheel ring gear, thereby reducing the likelihood of milling when the starter motor provides torque to the starter pinion.

Abstract: The device for preventing sudden starting of an automobile includes a starting motor, a power source, a starting switch, a solenoid switch, first and second connecting terminals and an actuator. The starting switch is electrically coupled to the power source. The solenoid switch is mechanically coupled to the starting motor and electrically coupled to the starting switch. The first and second connecting terminals are spaced apart from one another. The first connecting terminal is electrically coupled to the starting motor and the second electrical terminal is electrically coupled to the starting switch. The actuator is disposed between the connecting terminals for effecting an electrical connection between the connecting terminals to apply operating power to the starting motor when both the starting switch is in an ON position and the actuator is supplied with an operating pressure generated by depression of a brake pedal.

Abstract: A kick start switch modification kit and method for modifying an electric starter system on a motorcycle to a foot-operated electric starter simulating the classic foot operated kick start mechanism. Novel components which are contained in the modification kit include a foot pedal assembly, a rotating shaft, a switch engaging cam, a limit switch and a cover body having screw holes through which fasteners can pass which fasteners are in turn screwed into the cycle body where the classic kick start mechanism would be located.

Abstract: An engine cranking system includes an engine, a cranking motor coupled to the engine, a battery coupled to the cranking motor and to a system ground and a capacitor. First and second electrical paths interconnect the capacitor with the cranking motor and the system ground. The system further includes first and second switches and a first relay included in one of the first or second electrical paths. The first relay is moveable between at least a closed-circuit position, wherein the first relay completes one of the first and second electrical paths, and an open-circuit position, wherein the first relay interrupts one of the first and second electrical paths. The first switch is coupled between the first relay and the capacitor.

Abstract: A method and a device for starting an engine system, especially of a vehicle, which make possible a start of the engine system that is as quick and comfortable as possible. In this context, it is tested for a start request whether a starter-free starting method leads to a successful start of the engine system. For the case in which the test result is negative, the engine system is started automatically using a starter.

Abstract: A start control apparatus of an internal combustion engine comprises an ignition device for igniting an air-fuel mixture in a combustion chamber of the internal combustion engine, a start demanding device for demanding a start of the internal combustion engine, a starting device for starting the internal combustion engine, a determining device for determining a possibility of a self-ignition of the internal combustion engine at a time when a start demand is issued from the start demanding device, and a start procedure control device for igniting the air-fuel mixture in the combustion chamber by the ignition device after the start demand from the start demanding device in the case where the determining device determines that the possibility of the self-ignition of the internal combustion engine is higher than a predetermined level, thereafter starting the internal combustion engine by the starting device.

Abstract: A method for starting an internal combustion engine of a hybrid drive of a motor vehicle, the internal combustion engine and at least one electric motor being mechanically linkable to an output shaft of the hybrid drive via a gear system. The output shaft of the hybrid drive is placed in rotary motion, and at least one of the electric motors is switched to a generator mode by the gear system and by a control system.

Abstract: A control apparatus for protected switching of a load encompasses at least two switch units in series with a load, to permit delivery of energy to a load when each switch unit is switched on and to block it when at least one of the switch units is shut off; an electronic control system for triggering each switch unit via a first switching path and second switching paths, and for monitoring its state; a delay element on the first switching path, such that each switch unit can be shut off both by way of a shutoff signal conveyed via the first switching path and by way of a shutoff signal conveyed via the second switching path; and in a state in which one of the switch units is shut off and the other is switched on, the electronic control system ascertains a malfunction of the first switching path if, after output of a shutoff signal on the first switching path, the other switch unit does not shut off within a predefined time window.

Abstract: A vehicle and method are provided that control engine start in the vehicle. The vehicle includes an electric machine operable to provide a starting torque to the engine. The vehicle also includes a battery capable of providing energy to operate the electric machine. A number of battery parameters are determined, including a discharge power limit, an output power, and an engine starting power level. The engine starting power level is related to the discharge power limit and an amount of output power for the battery necessary to operate the electric machine to provide the starting torque to the engine. When the output power of the battery is at or above the engine starting power level, the engine is automatically started.

Abstract: In a method of starting an internal combustion engine, a combustion energy is generated by combusting a fuel that has been injected into a cylinder in an expansion stroke when the internal combustion engine is stopped. In the aforementioned method, the combustion energy generated by combusting the fuel is obtained based on a state of an air/fuel mixture within the cylinder to which the fuel has been injected. Based on the obtained combustion energy, a kinetic energy to be supplied to the internal combustion engine from a primary energy supply source is estimated. A difference between a predetermined target kinetic energy required for starting the internal combustion engine subsequent to the start of combustion and the estimated kinetic energy to be supplied from the primary energy supply source is obtained. The kinetic energy corresponding to the obtained difference is supplied from a secondary energy supply source in the form of a starter motor.

Abstract: A load operating means controls electricity supplied from a power source to a starter in an auxiliary system for starting an engine. An engine control means and an auxiliary electricity supply means turn the load operating means ON for supplying electricity from the power source to the starter in accordance with electricity supply from a power supply device when the engine is started. When voltage of the power supply device becomes less than a reset level, the engine control means resets electricity supply to the load operating means. When the engine control means starts the engine, the auxiliary electricity supply means supplies electricity to the load operating means at a timing simultaneously with or in advance of supplying electricity by the engine control means. When the engine control means resets the electricity supply, the auxiliary electricity supply means supplies electricity instead of the engine control means.

Abstract: An engine starter includes a starter motor which has an armature, a series-wound field coil and a parallel-wound field coil and a short-circuiting unit for short-circuiting the series-wound field coil under a predetermined engine starting condition. The series-wound field coil has a suitable current limiting resistance. The short-circuiting unit short-circuits the series-wound field coil after a crankshaft of an engine passes a first top dead center of an engine.

Abstract: A method for controlling starting of an internal combustion engine in a hybrid electric vehicle powertrain having multiple power flow paths to vehicle traction wheels from the engine and from an electric motor. A smoothness factor is calculated to determine how smooth an engine start should be. Engine operating variables regulate engine smoothness during engine start events as determined by the calculated smoothness factor appropriate for selected vehicle operating conditions.

Abstract: A stop position control apparatus of an internal combustion engine is applied to a vehicle having of a motor or a generator connected to a crankshaft of the engine, such as an economic-running vehicle and a hybrid vehicle. A rotation position of a motor generator is detected by a motor angle sensor, and a crank angle of the engine is detected by a crank angle sensor. A stop position of the internal combustion engine, at the time of stoppage is estimated based on the rotation position of the motor generator and the crank angle. By utilizing the results, the stop position of the internal combustion engine can be accurately estimated. By detecting a rotation direction of the crankshaft, the stop position of the engine can be accurately estimated even when the engine is rotated in the reverse direction at the time of the engine stopping.

Abstract: A starter for cranking an internal combustion engine is composed of an electric motor, an output shaft driven by the motor, a pinion gear coupled to the output shaft, and a magnetic switch. Electric power is supplied to the motor from an on-board battery through a switch, a movable contact of which is driven by the magnetic switch. The movable contact is connected to a brush lead wire via a connection formed by soft-soldering. The connection formed by the soft-soldering is positioned close to the commutator and covered with an end cover, so that the temperature of the connection becomes higher than other places in the starter. The connection easily melts away to thereby shut off power supply to the motor when its temperature becomes unusually high, and thereby the starter is protected from overheating.

Abstract: A powertrain includes a diesel compression engine and an electric machine operatively coupled thereto and effective to rotate the engine during engine cranking. Cold engine cranking is accomplished in a staged manner including a first stage wherein the engine is cranked to a first speed below the resonant speed of the coupled engine and electric machine combination for a first duration and thereafter cranked to a second speed above the resonant speed for a second duration. Transition out of cranking at the first and second speeds is accomplished when relative combustion stability is demonstrated. Cranking at the first or second speed is aborted when excessive crank times or if low battery voltages are observed. A third stage is included wherein the engine is cranked to a third speed below the engine idle speed. Transition out of cranking at the third speed is accomplished when relative combustion stability is demonstrated, whereafter normal engine control takes over.

Abstract: An engine startup fuel control system for use with a four-cycle internal combustion engine of the type having a plurality of combustion chambers, an air intake passageway, a source of fuel, a crankshaft and a camshaft which operates the engine cylinder valves. A multipoint fuel injector is associated with each combustion chamber and each multipoint fuel injector has an inlet connected to the fuel source and an outlet connected to the air intake passageway adjacent its associated combustion chamber. A crankshaft position sensor generates an output signal representative of the angular position of the crankshaft while, similarly, a camshaft position sensor generates an output signal representative of the angular position of the camshaft. An engine control unit is programmed to determine the synchronization of the engine in response to the output signals from the crankshaft position sensor and camshaft position sensor.

Abstract: A series type hybrid electric vehicle that controls an internal combustion engine, generator, and electric motor for reducing the load applied to the internal combustion engine when the internal combustion engine is restarted, lowers the thermal stresses to the internal combustion engine when the engine is turned off and is able to remove excess fuel when turning off the internal combustion engine.

Abstract: A method for controlling starting of an internal combustion engine in a hybrid electric vehicle powertrain having multiple power flow paths to vehicle traction wheels from the engine and from an electric motor. A smoothness factor is calculated to determine how smooth an engine start should be. Engine operating variables regulate engine smoothness during engine start events as determined by the calculated smoothness factor appropriate for selected vehicle operating conditions.

Abstract: The speed of rotation and the angular position of the rotating part (2, 3) of the engine (1) are measured continuously, and the fuel injection is cut off at predetermined speed and angular position values of the rotating part (2, 3) in order to stop the engine in a predetermined position that facilitates restarting the engine. In order to restart the engine, using a starter (4), fuel is injected into at least one cylinder of the engine when the piston moving in the cylinder is in a determined position. The spark ignition and/or fuel injection is interrupted at predetermined speed and angular position values of the rotating part (2, 3) of the engine (1), and fuel is injected into at least one cylinder of the engine (1) during the last revolution of the engine before stopping. In order to restart the engine, ignition is carried out in at least one cylinder, the piston of which is in the compression position at the moment when the engine (1) stops.

Abstract: An apparatus, method, and recording medium for controlling starting of an internal combustion engine. The apparatus for controlling starting of an internal combustion engine is provided with a clutch for connecting and disconnecting a motor and the internal combustion engine, which is installed in a vehicle. When starting the internal combustion engine, the clutch is released and the motor is maintained in an actuated state, and the clutch is engaged after the motor enters a predetermined rotation state.

Abstract: An engine cranking system includes an engine, a cranking motor coupled to the engine, a battery, a capacitor and an ignition switch. A first relay is connected between the cranking motor and system ground. A second relay is moveable between at least an open-circuit condition and a closed-circuit position to complete an electrical path connecting the capacitor with the cranking motor. The first relay is connected between the capacitor and the second relay. In one embodiment, a running engine sensory component is coupled between the first relay and system ground. In another embodiment, the engine cranking system includes a running engine sensory component connected to a relay and a control module connected to the relay and the capacitor. In one embodiment, a momentary switch is coupled between the capacitor and the relay.

Abstract: A method for controlling an engine and a belt-driven integrated starter (B-ISG) connected to the engine. The method includes determining engine running indicators and engine stopped indicators. Based on the indicators, the method controls the engine and the B-ISG for coordinating engine stops and starts with a capability of the B-ISG to start the engine.

Abstract: A starting system for a pump includes a driving motor, an electric source, a selector switch, a starter sensor, a temperature sensor and a control unit. The selector switch is located between the driving motor and the electric source for reversing polarity of the electric power supplied from the electric source to the driving motor. The starter sensor senses whether or not the driving motor has been started. The temperature sensor senses a temperature. The control unit operates the selector switch so as to repeatedly give the driving motor indications of reverse rotation and normal rotation in a case where the starter sensor does not sense that the driving motor has been started even if the control unit operates the selector switch so as to give the driving motor the indication of normal rotation in a state where the temperature sensed by the temperature sensor is below a preset temperature.

Abstract: A stating device for an internal combustion engine predicts whether a starter is required to assist a crank of the engine before igniting fuel in a cylinder in an expansion stroke, and starts the starter before igniting the fuel in a cylinder in an expansion stroke if it is decided that the starter is required.

Abstract: A device for and method of decarboning a combustion chamber and compression rings in an internal combustion engine. The device is a squid shaped container with a cylindrical body, a screw cap, and conduits depending from the body for transmitting cleaner to the combustion chambers on the engine. Once cleaner is transmitted to the combustion chambers, the engine is bumped to work the fluid into the compression rings using an automated system with a timer. When the engine is bumped, the device allows the cleaner to be vented to the device to avoid hydrolocking the engine. The device also contains the cleaner so that it is not splashed outside the engine.

Abstract: An engine is automatically stopped when a predetermined amount of time has passed with a predetermined stopping condition being fulfilled, even if learning is not yet complete, when an automatic stopping condition of the engine and a learning execution condition of a control amount of the engine during idling have been fulfilled. However, the engine is prohibited from automatically stopping until the learning is complete when the learning history of the control amount has been cleared by battery disconnection or the like and is not stored. Accordingly, it is possible to both simultaneously control an idling stop when the engine is idling and learn the control amount, as well as minimize a strange sensation felt by the driver that arises from an idling stop not being performed.

Abstract: In one aspect of the invention, a system for preventing stall of a vehicle engine is provided. The system includes an integrated starter alternator operably connected with the engine. The integrated starter alternator is capable of selectively operating as a starter motor for transmitting torque to the engine and as an alternator for producing electric energy. The system also includes at least one electric energy storage device in electrical communication with the integrated starter alternator. The system further includes at least one controller in electrical communication with the integrated starter alternator. The system includes at least one sensor operably connected with the engine sending a signal indicative of engine performance to the controller. The controller compares the signal to a predetermined condition indicative of engine stall and controls the electric energy storage device and the integrated starter alternator to transmit a torque to the engine sufficient to prevent engine stall.

Abstract: A starter/battery charger, which is coupled to an internal-combustion engine, operates as a starting motor for starting the engine and also operates as a charging generator for charging a battery after the engine has been started. Control unit controls the rotation speed of the engine by performing a driving control and a braking control on the starter/battery charger. The control unit carries out a judgement that a self-ignition state has been established in the engine depends on one of the rotation speed of the engine and a variation rate of the rotation speed has exceeded a prescribed value. The control unit switchs from the driving control to the braking control upon the judgement, thereby preventing the overshoot in the rotation speed of the engine.