Hitachi, Ltd.

Matsuo Amano

Takao Sasayama

Shinichi Sakamoto

Takeshi Hirayama

Toshimichi Minowa

Naoyuki Ozaki

Yasunori Mouri

Hiroshi Ohnishi

Nobuo Kurihara

Junichi Ishii

Masayuki Miki

Mineo Kashiwaya

Toru Sugawara

Seiji Suda

Masami Shida

Masahide Sakamoto

Takeshi Atago

Osamu Abe

Masumi Imai

Shirou Baba

Sigeyuki Kobori

Hiroshi Kuroiwa

Toshio Ishii

Yutaka Nishimura

Kiyoshi Miura

Sadayasu Ueno

Nobuo Sato

Katsuji Marumoto

Seiko Suzuki

Kiyoshi Horibe

Toshio Furuhashi

Mitsuhiro Masuda

Shigeru Horikoshi

Takao Teranishi

Junichi Makino

Kazuto Kinoshita

Yoshikazu Aochi

Ichiro Kimura

Nobuo Satou

Seikoo Suzuki

Masami Shiida

An engine power train control method and control apparatus for a vehicle having an engine and an automatic transmission is capable of quickly changing an air-fuel ratio to meet the requirements for exhaust gas without producing shocks and without reducing engine torque. An air-fuel ratio command value is varied stepwise for transition between an air-fuel ratio for lean-burn operation and a stoichiometric air-fuel ratio, and at the same time, the period following the completion of the stepwise variation of the air-fuel ratio command value, a basic fuel amount fed to the engine is varied stepwise from a value determined according to the air amount and an engine speed to a value determined according to a position of an accelerator pedal of the vehicle and the engine speed. In this way, shocks do not occur and the operability is improved, because the engine torque remains substantially constant through the air-fuel ratio transition.

Engine power train control method and control apparatus for a vehicle

The invention provides an output torque control method and apparatus for a lean burn internal combustion engine which accounts for aging of component parts, and in which no stepwise change of torque or shock occur when an air fuel ratio is changed. The method and apparatus according to the invention control an intake air amount while maintaining an emission purification function by controlling the air fuel ratio to that of a theoretical mixture (air fuel ratio of 14.7) in a case where a limit NOx emission is determined by using a detected air fuel ratio and lean burn operation becomes difficult due to the amount of NOx emissions. Abrupt change of an output torque when the air fuel ratio is changed is curtailed by controlling a fuel amount or an air amount after calculating the fuel amount or the air amount from an engine speed and an accelerator depression angle.

Output torque control apparatus and method for an internal combustion

In a valve control apparatus for an automobile, an H-bridge type chopper main circuit 4 is operated by a control signal PWM from a microcomputer 1 to thereby drive a motor 9 for controlling a throttle valve 10. The power element current from the chopper main circuit 4 is detected by a shunt resistor 5 in the form of a voltage, and the detected voltage is amplified by an amplifier 6 and then taken into the microcomputer 1 through a sample hold circuit 12 and an A/D converter. The sample hold circuit 12 is operated in synchronism with the control signal PWM from the microcomputer 1. Further, the A/D converter is also operated in synchronism with the control signal PWM from the microcomputer 1. The motor 9 is controlled by a throttle valve opening angle command and a throttle valve opening angle signal, and further the motor 9 is controlled by a detected motor current.

Valve control apparatus for an automobile

A torque detection mechanism can be provided for a power train and its control unit without newly adding a sensor and its signal processing module. As a gear pair for the torque detection mechanism of a phase difference type, existing gears in a transmission are used, or a gear pair for this mechanism are provided adjacent to these existing gears. From phase signals sent from pickups, a phase difference signal is obtained by use of one part of existing devices in the control unit. The torque detection mechanism can be realized with the minimum number of component parts by utilizing the existing members and spaces instead of newly adding a sensor and its module. The invention can be applied to either of FF and FR cars, and has a practical structure in respect of the performance, costs and reliability.

Torque detection apparatus of power train

A car control apparatus in which correction characteristics indicating whether or not various control constants are proper or not are calculated through loop control of one of the car's operation parameters, such as the air-fuel ratio, on the basis of the air-fuel ratio correction factors subjected to learning to thereby rationalize the control constants such as the fundamental injection time so as to realize proper fuel injection and proper ignition timing control.

Apparatus and method for controlling a car

An engine control system is disclosed in which the air-fuel ratio is controlled by feedback in accordance with the oxygen concentration detected of the exhaust gas, and a feedback control system thereof separate learning compensation values for compensating for the changes of the input/output characteristics of an air flow meter and a fuel injector respectively. The engine control system comprises a device for detecting the engine intake air flow, a device for detecting the engine speed, a device for detecting the oxygen concentration of the exhaust gas, a device for calculating the error between actual and target air-fuel ratios from the oxygen concentration of the exhaust gas, a device for learning the changes in the input/output characteristics of the intake air flow, a detection device to determine a first compensation factor corresponding to the changes in the input/output characteristics thereof, a device for learning the changes in the input/output characteristics of the fuel injection device to determine a second compensation factor corresponding to the changes in the input/output characteristics thereof, a device for calculating a basic fuel injection amount from the first compensation factor, the engine speed and the intake air amount, a device for calculating a required fuel flow rate reducing the air-fuel ratio error from the basic fuel injection amount, the second compensation factor and the air-fuel ratio error, a device for generating a drive signal indicating the required fuel flow rate, and the device for injecting fuel into the intake air path in the engine in response to the drive signal indicating the required fuel flow rate.

Engine control system using learning control

In a control apparatus for an internal combustion engine for receiving outputs of a crank angle sensor, air flow sensor, etc., calculating control values from these outputs using a microcomputer to actuate actuators; calculated timings at which the respective actuators are deactuated are compared in advance with each other, the control value for the actuator which should be deactuated earliest is stored in an output compare register, and a deactuation signal for the actuator is generated with count matching of two inputs to a comparator of the output compare register. Thus the respective actuators are sequentially controlled.

Control apparatus and method for an internal combustion engine

A method for feedback controlling air-fuel ratio of the mixture supplied to an internal combustion engine having a plurality of cylinders comprises the steps of, detecting respective air-fuel ratios of the exhaust gas from the respective cylinders with an air-fuel ratio sensor having a substantially linear output characteristic; calculating an average air-fuel ratio by using the latest detected air-fuel ratios of the respective cylinders; determining a fundamental feedback correction coefficient .beta..sub.0 for a cylinder of which air fuel ratio is feedback controlled next; retrieving a learning correction coefficient .beta..sub.1 for the cylinder of which air-fuel ratio is feedback controlled next from a learning map prepared by learning for the corresponding cylinder; and determining new learning correction coefficients .beta..sub.1 for the respective cylinders using respective deviations of the respective detected current air-fuel ratios from the latest average air-fuel ratio calculated in the previous step, whereby air-fuel ratio control at any desired air-fuel ratio is carried out with a high accuracy and with a uniform air-fuel ratio throughout the whole cylinders.

Method for feedback controlling air and fuel ratio of the mixture

A learning map on which the rewriting of data is performed in accordance with the results of an internal combustion engine controlling operation is provided. When the number of pieces of data written in this learning map has become greater than one, the corresponding weighting is done for each unlearned region in the basis of the learning data on the learning already-learned regions, and the data in the already learned regions is written in unlearned region. The controlling of the engine is performed on the basis of the data written in the learning map.

Learning control method for internal combustion engines

A novel method of controlling air-fuel ratio for an internal combustion engine is disclosed, which comprises a memory area for holding regional compensation factors used for air-fuel ratio control, a memory area for holding new regional compensation factors obtained by learning, and a memory area for holding regional compensation factors based on the result of the learning immediately before the latest learning, thus rationalizing the new setting and updating proceses of regional compensation factors according to the result of learning.

Method of controlling air-fuel ratio

A combustion pressure detecting apparatus for generating an electrical signal in response to a combustion pressure of an internal combustion engine, wherein an electrical signal based on said combustion pressure is detected at a predetermined angle of rotation of said engine, the detected value being compared with a predetermined reference value to derive a difference therebetween, including correcting means for executing correcting operations in dependence on said difference.

Method and apparatus for detecting combustion pressure in engine

A novel method of controlling air-fuel ratio for an internal combustion engine is disclosed, which comprises a memory area for holding regional compensation factors used for air-fuel ratio control, a memory area for holding new regional compensation factors obtained by learning, and a memory area for holding regional compensation factors based on the result of the learning immediately before the latest learning, thus rationalizing the new setting and updating processes of regional compensation factors according to the result of learning.

Method controlling air-fuel ratio

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Hitachi, Japan

Matsuo Amano