A hybrid vehicle is provided with an one-way clutch configured to prevent the reverse rotation of an engine, a power split device, a display unit configured to notify a driver of a warning message, and an ECU configured to control the engine, the display unit and a motor generator. The ECU controls the display unit to notify the driver of a warning message that the vehicle is not allowed to make reverse moving when a malfunction occurs. In the case where a malfunction occurs, the output shaft cannot rotate reversely if the reverse rotation of the engine is prevented by the one-way clutch.

An engine stopping system for reducing electric consumption by interrupting power supply to a motor during disengagement of a clutch is provided. The engine stopping system is applied to a vehicle in which the clutch is interposed between an engine and a power distribution device. The engine stopping system is configured to interrupt power supply to the motor while bringing the clutch into disengagement, when an input speed N.sub.in falls below a threshold value , under conditions that the engine does not generate power during engagement of the clutch, and that the motor generates electricity utilizing an inertia torque of the engine while controlling an output torque of the motor to lower the engine speed.

A vehicle includes an engine, an MG (motor generator) an MG2, a planetary gear device mechanically coupled to the engine and MG1 and MG2, a battery, an inverter configured to perform a power conversion between the battery and MG1 and between the battery and MG2, and a controller. MG1 generates a counter-electromotive torque when rotated by the engine. During an inverter-less running control where the inverter is put into a gate shut-off state and the engine is driven to cause MG1 to generate the counter-electromotive torque, the controller decreases a engine target rotation speed Netag when an integrated value of battery charging current (deterioration evaluation value D) is greater than a predetermined value (threshold value D1) smaller than the engine target rotation speed Netag when the deterioration evaluation value D is equal to or smaller than the threshold value D1.

A method for monitoring/controlling starting of a heat engine of a hybrid vehicle including at least one electrical engine, including: launching a simulated sequence for starting the heat engine by using a start battery; measuring and recording progress over time of at least one parameter of the start battery, including a given current strength and voltage at terminals of the start battery; and detecting whether or not the progress over time of the at least one parameter reaches a predetermined value defining a state of the start battery, with or without a required capacity, for starting the heat engine during a predetermined time interval.

A method to control an electric motor including the steps of: determining a target torque; calculating a target current by dividing the target torque by a torque constant; determining an equivalent impedance by means of a predetermined map; calculating the voltage drop by multiplying the target current by the equivalent impedance; calculating a counter-electromotive force by multiplying an actual rotation speed by a speed constant; determining a control voltage to be applied to the power supply terminals of the electric motor by adding the voltage drop to the counter-electromotive force; determining an offset parameter; and correcting the equivalent impedance provided by the predetermined map by applying the offset parameter.

A control apparatus is applied to a hybrid vehicle including an internal combustion engine that is capable of changing over its combustion state between lean combustion and stoichiometric combustion. The control apparatus executes noise suppression control by limiting the operating point of the internal combustion engine to be upon a noise suppression line for lean combustion or to be upon a noise suppression line for stoichiometric combustion, so that the noise generated by a power transmission mechanism is suppressed. When changing over from lean combustion to stoichiometric combustion during execution of noise suppression control, the control apparatus of the present invention changes the air/fuel ratio after changing the operating point of the internal combustion engine from one point to a point that is more toward the lower torque side of the noise suppression line.

A vehicle control system is provided to reduce a change in drive force and to start an engine without delay when starting the engine by a motor during running. The control system is applied to a hybrid vehicle having an internal combustion engine and two motors supplied electric power from a battery. The control system comprises a determination means that determines a fact that a state of charge of the battery is lower than a first threshold, during propelling the vehicle by the two motors by supplying the electric power from the battery while stopping the engine (at step S2); and a drive force restriction means that restricts a total drive force of said two motors for propelling the vehicle to an allowable limit which is lower than a theoretical maximum drive force of said two motors, given that the state of charge of the battery is lower than a first threshold (at step S3).

An apparatus for activating a catalyst of a hybrid vehicle may include: an engine including a plurality of cylinders, at least one intake valve and at least one exhaust valve, a variable valve apparatus adjusting lift and opening timing of the intake valve and exhaust valve, an integrated starter-generator, a driving information detector detecting driving information including a vehicle speed, a displacement of an accelerator pedal, and a displacement of a brake pedal, an exhaust gas purification apparatus, and a controller cutting off fuel supplied into the cylinder, opening the exhaust valve by using the variable valve apparatus during a suction stroke, and generating electrical energy through the integrated starter-generator when a regenerative braking condition of a hybrid vehicle is satisfied from the driving information detected by the driving information detector.

A motor-assisted non-uniform displacement engine control system includes a non-uniform displacement engine comprising a plurality of cylinders, the cylinders comprising at least two kinds of cylinders having different displacements, a motor connected to a driving shaft of the engine, an energy storage device for supplying electrical energy to the motor, and a motor control unit for controlling the motor, wherein the motor control unit controls the motor to compensate for a difference in torque due to different displacements of the cylinders such that a sum of engine torque and motor torque during an explosion stroke of each cylinder is uniform.

According to the present invention, if a required power generation signal is supplied while a vehicle is decelerated in a fuel-efficiency-oriented control mode, an electrically-operated waste gate valve is operated so that opening of the electrically-operated waste gate valve is increased as the required power generation amount increases. Then, if it is determined that the vehicle is decelerated on the basis of accelerator opening and a vehicle speed, and fuel is cut off, an electronically controlled throttle valve is operated toward a fully opened side. In addition, if any one of following conditions is satisfied: the fuel-efficiency-oriented control mode is not selected; there is supply of a required output signal; and the vehicle is not decelerated, opening of the electrically-operated waste gate valve is adjusted so that output torque of an engine becomes a required output value.