Abstract: Unless the steering operation quantity detected by a steering quantity detection unit indicates that the vehicle is advancing almost rectilinearly, an approach disallowed area present toward the outer side of the turning vehicle relative to the front of the vehicle along the advancing direction, such as a road boundary, a blocking wall or a white line, is detected by an approach disallowed area detection unit. A mode judging unit judges that a steering angle limit mode is set if an approach disallowed area has been detected. An &agr; calculating unit calculates an angle &agr; formed by the orientation of the approach disallowed area boundary and the orientation of the vehicle.

Abstract: A reference steering angle achieved when the steering operation quantity is sustained at a constant value is calculated in correspondence to the steering operation quantity. A decision is made as to whether the vehicle is in a turn-contracting state, in which the direction of a steering operation matches the direction of a change made in the steering operation or a turn-expanding state in which the direction of the steering operation is opposite from the direction of the change made in the steering operation. If the vehicle is determined to be in a turn-contracting state, the target steering angles for the front wheels and the rear wheels are calculated by correcting the reference steering angle so as to achieve a smaller steering center elevation angle.

Abstract: An intake air control system for an engine having an air intake passage, a throttle valve in the intake passage and an intake valve for selectively opening and closing communication between the intake passage and a cylinder. The control system determines target intake passage pressure and target intake air amount in accordance with engine operating conditions. A target throttle opening is set in accordance with both the target pressure and the target intake air amount. The throttle valve is then driven to the target opening. Intake passage pressure is detected and a target intake valve open/close timing is determined in accordance with both the detected intake passage pressure and the target intake air amount. The intake valve is then driven in accordance with the target open/close timing.

Abstract: An intake-air quantity control apparatus for an internal combustion engine with a variable valve timing system associated with at least an intake valve, comprises a control unit controlling an intake-air quantity of air entering the internal combustion engine based on at least one of an intake valve open timing and an intake valve closure timing of the intake valve. The control unit determines a desired internal pressure in an intake-air passage based on a predetermined operating parameter, and detecting an operation delay-time fluctuation rate for at least the intake valve. A desired intake-air quantity is arithmetically calculated on the basis of engine operating conditions. The control unit includes a compensation section which compensates for the desired internal pressure based on at least one of the operation delay-time fluctuation rate and the desired intake-air quantity to produce a compensated internal pressure.

Abstract: When an air conditioner is turned on during homogeneous operation, an equivalence ratio correction factor &Dgr;&phgr; is increased sharply and suddenly in such a manner as to show a jump for thereby increasing an engine output torque, and thereafter is decreased gradually with increase of a cylinder intake air quantity, whereby to maintain the engine output torque constant. However, when switching to a homogeneous mode occurs in the middle of the above control, switching to proper torque correction is not carried out at the time of a homogeneous combustion mode, i.e., torque correction by the use of ignition timing but the torque correction by the equivalence ratio correction factor &Dgr;&phgr; continuously. By this, in contrast to the case in which the torque correction is switched to one that is carried out by the use of ignition timing correction quantity, a sharp and sudden variation of engine output torque can be prevented.

Abstract: When an air conditioner is turned on during homogeneous operation, an equivalence ratio correction factor .DELTA. .phi. is increased sharply and suddenly in such a manner as to show a jump for thereby increasing an engine output torque, and thereafter is decreased gradually with increase of a cylinder intake air quantity, whereby to maintain the engine output torque constant. However, when switching to a homogeneous mode occurs in the middle of the above control, switching to proper torque correction is not carried out at the time of a homogeneous combustion mode, i.e., torque correction by the use of ignition timing but the torque correction by the equivalence ratio correction factor .DELTA. .phi. continuously. By this, in contrast to the case in which the torque correction is switched to one that is carried out by the use of ignition timing correction quantity, a sharp and sudden variation of engine output torque can be prevented.

Abstract: A cylinder direct-injection spark-ignition engine using at least a homogeneous combustion mode where early fuel-injection on intake stroke produces a homogeneous air-fuel mixture and a stratified combustion mode where late fuel-injection on compression stroke produces a stratified air-fuel mixture, is equipped with an electronic engine control unit connected to an electronic fuel injection system, an electronic spark-timing control system, and an electronically-controlled throttle valve. The control unit permits switching to a homogeneous combustion mode and changes the manipulated variable for engine torque correction to a spark-timing correction quantity, immediately when the demand for switching from stratified to homogeneous combustion mode occurs during a high-response torque correction.

Abstract: In an engine comprising a fuel vapor purge mechanism which mixes fuel vapor from a fuel tank with the intake air of the engine after fuel vapor has been adsorbed by a canister, a uniform fuel-air mixture and a stratified fuel-air mixture are selectively produced. When the engine is running with a stratified fuel-air mixture, purge of fuel vapor is prohibited. On the other hand, when the fuel vapor adsorption amount in the canister has reached a predetermined value, the engine is forcibly run with a uniform fuel-air mixture and purge of fuel vapor is performed, In this way, the fuel vapor adsorption amount in the canister is prevented from becoming excessive.

Abstract: A control system for an internal combustion engine having an intake air amount regulating device and a fuel supply device. The control system comprises a device for detecting an engine operating condition of the engine, and a control unit.