Abstract: An ignition timing control apparatus and method for an internal combustion engine, and an engine control unit are provided for more rapidly and effectively restraining knocking as the entire internal combustion engine, and extending the lifetime of the internal combustion engine. The ignition timing control apparatus comprising an ECU. The ECU determines a basic ignition timing on a cylinder-by-cylinder basis, calculates a knock intensity on a cylinder-by-cylinder bases based on a detected signal of a cylinder inner pressure sensor, and updates a correction coefficient learning value for a corresponding cylinder when the knock intensity is larger than a predetermined first determination value and is smaller than a predetermined second determination value larger than the predetermined first determination value, and updates the knock intensities for all the cylinders when the one knock intensity parameter is equal to or larger than the predetermined second determination value.

Abstract: An in-cylinder pressure detection device for an internal combustion engine, which is capable of calculating a hysteresis amount properly to thereby detect in-cylinder pressure with high accuracy. The in-cylinder pressure detection device comprises an in-cylinder pressure sensor that detects in-cylinder pressure as a detected in-cylinder pressure. The in-cylinder pressure detection device estimates an in-cylinder pressure generated when combustion is not performed in the cylinder, as a motoring pressure, calculates a hysteresis amount indicative of a difference between the detected in-cylinder pressure and an actual in-cylinder pressure, based on the detected in-cylinder pressure and the motoring pressure obtained during the exhaust stroke of the engine, and corrects the detected in-cylinder pressure based on the calculated hysteresis amount.

Abstract: An air-fuel ratio control system for an internal combustion engine, which is capable of accurately estimating an exhaust gas state parameter according to the properties of fuel, thereby making it possible to properly control the air-fuel ratio of a mixture.

Abstract: An engine control unit includes pressure detector provided in a combustion chamber of the engine. A motoring pressure of the engine is estimated. A combustion starting time is detected when the difference between an internal pressure detected by the pressure detector and the pressure estimated by the ECU exceeds a predetermined value. When the internal pressure detected by the pressure detector reaches its peak after the combustion starting time has been detected, the crank angle at this time point is determined to correspond to the maximum internal cylinder pressure that is generated by combustion.

Abstract: The present invention provides a control apparatus for a plant, which can suppress excessive correction for a spiky disturbance being applied and maintain a good controllability, when controlling the plant, which is a controlled object, with the self-tuning regulator. A detected equivalent ratio KACT is input to a high-pass filter 33, and a high-pass filter output KACTHP is input to a parameter adjusting mechanism 42. The parameter adjusting mechanism 42 calculates a corrected updating vector (KID·d?(k)) by multiplying an updating component d? of a model parameter vector by a correction coefficient KID, and adds the corrected updating vector to a preceding value ?(k?1) of the model parameter vector, to thereby calculate a present value ?(k). The correction coefficient KID is changed from “1.0” to a value near “0” upon detection of the spiky response where an absolute value of the high-pass filter output KACTHP increases.

Abstract: An air-fuel ratio control system for an internal combustion engine, which is capable of quickly and properly eliminating variation in air-fuel ratio between a plurality of cylinders. The air-fuel ratio control system 1 controls the amount of fuel to be supplied to first to fourth cylinders #1 to #4, on a cylinder-by-cylinder basis, thereby controlling the air-fuel ratio of a mixture supplied to each of the cylinders. A LAF sensor 14 delivers to an ECU 2 an output KACT indicative of the air-fuel ratio of exhaust gases emitted from the cylinders and merged. A cycle filter 23a and a rotation filter 23b filters the output KACT from the LAF sensor 14 such that components in respective bands of a first frequency fr1 and a second frequency fr2 are allowed to pass therethrough.

Abstract: There is provided a control system capable of realizing a highly robust control having a large margin of stability. The ECU of the control system controls the air-fuel ratio of exhaust gases emitted from the first to fourth cylinders. The ECU 2 estimates an estimation value of a detected air-fuel ratio, from a model defining a relation between the estimation value and a plurality of simulation values, and identifies an intake air amount variation coefficient such the estimation value becomes equal to a detected air-fuel ratio.

Abstract: A control apparatus for an exhaust gas recirculation valve is disclosed. The exhaust gas recirculation valve is provided in an exhaust gas recirculation pipe for recirculating exhaust gases from an internal combustion engine to an intake system of the engine. The exhaust gas recirculation valve controls an exhaust gas recirculation amount. An opening of the exhaust gas recirculation valve is controlled to a target opening, based on a controlled object model which is obtained by modeling the exhaust gas recirculation valve.

Abstract: An air-fuel ratio control system for an internal combustion engine, which is capable of quickly and properly eliminating variation in air-fuel ratio between a plurality of cylinders. The air-fuel ratio control system 1 controls the amount of fuel to be supplied to first to fourth cylinders #1 to #4, on a cylinder-by-cylinder basis, thereby controlling the air-fuel ratio of a mixture supplied to each of the cylinders. A LAF sensor 14 delivers to an ECU 2 an output KACT indicative of the air-fuel ratio of exhaust gases emitted from the cylinders and merged. A cycle filter 23a and a rotation filter 23b filters the output KACT from the LAF sensor 14 such that components in respective bands of a first frequency fr1 and a second frequency fr2 are allowed to pass therethrough.

Abstract: A method and an apparatus for estimating an amount of drawn air of a cylinder and a method and an apparatus for controlling the amount of drawn air, are presented. An estimated value of an amount of drawn air of the cylinder, based on intake manifold pressure, is multiplied by a value of an identification parameter obtained by an adaptive observer, to obtain a final estimated value of an amount of drawn air of the cylinder. An accurate estimated value in a transient state as well as an estimated value not oscillating in a steady state can be obtained. Accordingly, accuracy of air-fuel ratio control can be remarkably increased.

Abstract: The present invention provides a control apparatus for a plant, which can suppress excessive correction for a spiky disturbance being applied and maintain a good controllability, when controlling the plant, which is a controlled object, with the self-tuning regulator. A detected equivalent ratio KACT is input to a high-pass filter 33, and a high-pass filter output KACTHP is input to a parameter adjusting mechanism 42. The parameter adjusting mechanism 42 calculates a corrected updating vector (KID·d&thgr;(k)) by multiplying an updating component d&thgr; of a model parameter vector by a correction coefficient KID, and adds the corrected updating vector to a preceding value &thgr;(k−1) of the model parameter vector, to thereby calculate a present value &thgr;(k). The correction coefficient KID is changed from “1.0” to a value near “0” upon detection of the spiky response where an absolute value of the high-pass filter output KACTHP increases.

Abstract: An air-fuel ratio control system for an internal combustion engine is provided which is capable of appropriately and promptly correcting variation in the air-fuel ratio of a mixture between cylinders and realizing a very robust air-fuel ratio control, even with a complicated exhaust system layout. The ECU of the system for control of the air-fuel ratio of a mixture supplied to first to fourth cylinders determines a feedback correction coefficient, calculates a cylinder-by-cylinder variation coefficient indicative of variation in air-fuel ratio between the cylinders, based on a model parameter of a model having the input of the feedback correction coefficient thereto and the output of the detected air-fuel ratio, identifies the model parameter, corrects a basic fuel injection amount such that the cylinder-by-cylinder variation parameter converges to a moving average value thereof, thereby calculating a cylinder-by-cylinder final fuel injection amount.

Abstract: A control apparatus for an exhaust gas recirculation valve is disclosed. The exhaust gas recirculation valve is provided in an exhaust gas recirculation pipe for recirculating exhaust gases from an internal combustion engine to an intake system of the engine. The exhaust gas recirculation valve controls an exhaust gas recirculation amount. An opening of the exhaust gas recirculation valve is controlled to a target opening, based on a controlled object model which is obtained by modeling the exhaust gas recirculation valve.

Abstract: A method and an apparatus for estimating an amount of drawn air of a cylinder and a method and an apparatus for controlling the amount of drawn air, are presented. An estimated value of an amount of drawn air of the cylinder, based on intake manifold pressure, is multiplied by a value of an identification parameter obtained by an adaptive observer, to obtain a final estimated value of an amount of drawn air of the cylinder. An accurate estimated value in a transient state as well as an estimated value not oscillating in a steady state can be obtained. Accordingly, accuracy of air-fuel ratio control can be remarkably increased.

Abstract: There is provided a control system capable of realizing a highly robust control having a large margin of stability. The ECU of the control system controls the air-fuel ratio of exhaust gases emitted from the first to fourth cylinders. The ECU 2 estimates an estimation value of a detected air-fuel ratio, from a model defining a relation between the estimation value and a plurality of simulation values, and identifies an intake air amount variation coefficient such the estimation value becomes equal to a detected air-fuel ratio.

Abstract: An air-fuel ratio control system for an internal combustion engine is provided which is capable of appropriately and promptly correcting variation in the air-fuel ratio of a mixture between cylinders and realizing a very robust air-fuel ratio control, even with a complicated exhaust system layout. The ECU of the system for control of the air-fuel ratio of a mixture supplied to first to fourth cylinders determines a feedback correction coefficient, calculates a cylinder-by-cylinder variation coefficient indicative of variation in air-fuel ratio between the cylinders, based on a model parameter of a model having the input of the feedback correction coefficient thereto and the output of the detected air-fuel ratio, identifies the model parameter, corrects a basic fuel injection amount such that the cylinder-by-cylinder variation parameter converges to a moving average value thereof, thereby calculating a cylinder-by-cylinder final fuel injection amount.

Abstract: A drive system having a belt with a length and a plurality of teeth spaced regularly along the length of the belt and a first pulley having a plurality of grooves for receiving the belt teeth with the belt and first pulley in operative relationship. The single pitch difference between the belt teeth and the grooves in the first pulley is between -0.04 mm and 0 mm.

Abstract: A conveying belt having a belt body with oppositely facing inner and outer surfaces and a width between laterally spaced sides. The belt body has a first layer, with the first layer being an elastomer with a first plurality of discrete fibers therein having lengths substantially less than the width of the body. The lengths of the fibers in a second plurality of fibers in the first plurality of fibers are randomly oriented and reside substantially in a single plane. The invention is also directed to a method of making the conveying belt.

Abstract: A power transmission belt having a body with an inside and an outside, a length, and a plurality of teeth on one of the inside and outside of the belt body and spaced in a likewise direction. A load carrying cord is embedded in the belt body and extends lengthwise thereof. The load carrying cord is made up of a first plurality of monofilament aramid fibers, each having a denier of 0.5 to 2.0 and bundled to define a combined diameter of 0.10 to 0.20 mm.

Abstract: A toothed belt having a body with a length, laterally spaced sides, an inside and an outside, and defining a plurality of teeth spaced in a lengthwise direction on one of the inside and the outside of the body. The body is defined at least in part by a rubber composition made up of at least an ethylene propylene diene monomer (EPDM) and a diene rubber. A cloth layer is provided on the teeth on the one of the inside and the outside of the body. The cloth layer is treated with a resorcin-formalin-latex solution.