Nissan Motor Company Limited

Nobutaka Takahashi

Keisuke Suzuki

Yoshitaka Deguchi

Takeaki Obata

Hiroyuki Ueda

Toshimi Abo

Hiromasa Sakai

Ikuhiro Taniguchi

Kouichi Akabori

Musashi Yamaguchi

Kotaro Akashi

Tatsuo Morita

Yuki Nakajima

Yuji Kato

Hideo Nakamura

Hiroyuki Ashizawa

Hiroshi Satoh

Hideyuki Tamura

Makoto Yamashita

Itsuro Muramoto

Tetsuya Kamihara

Toshio Matsumura

Masashi Yamaguchi

Kazuma Okura

Tsuyoshi Sodeno

Kiyomi Kawamizu

Shozo Nakayama

A fuel cell system of the present invention includes: a fuel cell supplied with fuel gas and oxidizing gas to generate electricity; a fuel gas supply unit supplying the fuel gas to the fuel cell; an oxidizing gas supply unit supplying the oxidizing gas to the fuel cell; an aftercooler cooling the oxidizing gas supplied to the fuel cell by heat exchange with a coolant; an oxidizing gas temperature detector detecting temperature of the oxidizing gas; and a coolant circulation controller starting circulation of the coolant when the detected temperature of the oxidizing gas exceeds a predetermined value. The predetermined value is set to a value of not higher than a minimum electricity generation temperature of the fuel cell, and a circulation timing and flow rate of the coolant for the aftercooler are controlled such that the supplied oxidizing gas does not become cold. This enables the fuel cell to generate electricity at cold start-up.

Fuel cell system

A fuel cell system of the present invention includes: a fuel cell () supplied with fuel gas and oxidizing gas to generate electricity; a fuel gas supply unit supplying the fuel gas to the fuel cell (); an oxidizing gas supply unit supplying the oxidizing gas to the fuel cell (); an aftercooler () cooling the oxidizing gas supplied to the fuel cell () by heat exchange with a coolant; an oxidizing gas temperature detector () detecting temperature of the oxidizing gas; and a coolant circulation controller () starting circulation of the coolant when the detected temperature of the oxidizing gas exceeds a predetermined value. The predetermined value is set to a value of not higher than a minimum electricity generation temperature of the fuel cell (), and a circulation timing and flow rate of the coolant for the aftercooler () are controlled such that the supplied oxidizing gas does not become cold. This enables the fuel cell () to generate electricity at cold start-up.

A fuel cell system (FS) is provided with a fuel cell () having a fuel electrode () and an oxidizer electrode (), disposed in opposition thereto, between which an electrolyte membrane () is sandwiched, a fuel gas supply source () supplying fuel gas to the fuel cell through a fuel gas supply passage (), a fuel gas discharge section () discharging the fuel gas, discharged from the fuel cell, to an outside of a fuel cell system, and a control section () executing fuel gas substituting treatment such that, during startup of the fuel cell system, the fuel gas is discharged outside the fuel cell system through the fuel gas discharge section while supplying the fuel gas so as to cause a state quantity of the fuel gas, to be supplied to the fuel cell from the fuel gas supply source, to be constant for thereby allowing the fuel gas passage and the fuel electrode to be substituted with the fuel gas.

Fuel cell system and related startup method

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. If, on the other hand, the vehicle is determined to be in a turn-expanding state, target steering angles for the front wheels and the rear wheels are calculated by correcting the reference steering angle so as to achieve a larger steering center elevation angle. The steering angles at the front wheels and the rear wheels are adjusted independently of one another so as to match the steering angles with the target steering angles thus calculated.

Vehicle front/rear wheel steering angle control apparatus and vehicle front/rear wheel steering angle control method

A control system for a hybrid vehicle has a consumed electric power calculator ( ), which calculates electric power consumption, and a battery state calculator ( ), which calculates battery state SOC of a battery ( ). Based on this battery state, a physical quantity per effective electric power calculator ( ) calculates a physical quantity per effective power when electric power equal to or greater than consumed electric power is generated for various electric power consumption and electric power generation, and a threshold value calculator ( ) obtains a threshold value having the same unit as that of the physical quantity per effective power using predetermined calculation for selecting operating modes of a generator and the battery. An operating mode selector ( ) selects operating modes for an engine ( ) and the battery ( ) based on comparison between the above threshold value and the physical quantity per effective power corresponding to the consumed electric power, and a target generated electric power calculator ( ) calculates target electric power generation. An electric power distribution controller ( ) controls the engine ( ) and the motor ( ).

Control system for hybrid vehicle

A control system for an engine-CVT drive train controls engine torque change against inertia torque that would take place during ratio change due to inertia attached to the CVT input shaft. A target speed is computed from operator power demand and vehicle speed. A target ratio is computed from the target speed and vehicle speed. A ratio command is computed from the target ratio. The control system computes the inertia torque from the ratio command or the target ratio.

Engine-CVT drive train control system

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.

Intake air control system of internal combustion engine

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. A throttle opening is controlled depending on both the compensated internal pressure and the desired intake-air quantity. Also, the intake valve open timing and the intake valve closure timing are controlled depending on both the compensated internal pressure and the desired intake-air quantity.

Intake-air quantity control apparatus for internal combustion engine with variable valve timing system

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. In the meantime, after completion of the torque correction by the above mentioned control, the torque correction at the time of the homogeneous combustion mode is carried out by ignition timing correction. Further, when the combustion mode is switched to stratified combustion during execution of torque correction by ignition timing correction at the time of the homogeneous combustion mode, the torque correction is switched to one that is carried out by the use of the equivalence ratio correction factor simultaneously with switching of the combustion mode.

Control system for internal combustion engine

The invention prevents engine speed from being decreased (or engine stall) by a disturbance (such as turning on the air conditioner) during idling. During idle control, a target idle speed is used as an engine speed parameter in place of the actual engine speed to calculate intake air, so that the engine speed is not decreased by a disturbance for very long. Also, target generation torque can be set so as to maintain target idle speed.

Engine idle speed controller

In a combustion changeover of an internal combustion engine between a stratified combustion mode and a homogeneous combustion mode, an engine control system modifies an ignition timing to eliminate unwanted torque increase due to fuel increase. The controller determines an excess quantity, such as an excess factor of an actual intake air quantity with respect to a target intake air quantity, indicative of torque variation due to fuel increase, and determines an ignition timing modification quantity to eliminate the torque variation, in accordance with the excess quantity. With this modification quantity, the control system retards the ignition timing transiently and ensure smooth combustion changeover.

Ignition and combustion control in internal combustion engine

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. In the meantime, after completion of the torque correction by the above mentioned control, the torque correction at the time of the homogeneous combustion mode is carried out by ignition timing correction. Further, when the combustion mode is switched to stratified combustion during execution of torque correction by ignition timing correction at the time of the homogeneous combustion mode, the torque correction is switched to one that is carried out by the use of the equivalence ratio correction factor simultaneously with switching of the combustion mode.

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. When the demand for switching from homogeneous to stratified combustion mode occurs during the high-response torque correction, switching to the stratified combustion mode is inhibited for a brief time duration until a required torque correction value reaches a predetermined criterion to continue the high-response torque correction based on the spark-timing correction quantity.

Apparatus for controlling internal combustion engine

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.

Engine combustion controller

Engine rotation speed during idle running is feedback-controlled. A second target rotation speed which progressively decreases towards a first target rotation speed from a predetermined engine rotation speed, is set. The engine rotation speed is feedback-controlled based on a difference between a present rotation speed and this second target rotation speed. In this way, compared to the case where feedback control is performed using the first target rotation speed as a target value, the time period during which the engine rotation speed falls below the first target rotation speed is shortened and the engine rotation speed is made to stably converge to the first target rotation speed.

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Yokohama, Japan

Nobutaka Takahashi