Abstract: A vehicle exhaust treatment system includes an emission control device featuring at least one upstream NOx-storing “brick,” and a downstream NOx-storing “brick” that is substantially smaller in nominal capacity than the upstream brick. An oxygen sensor positioned between the upstream and downstream bricks generates an output signal representing the concentration of oxygen in the device. A controller selects a rich operating condition to purge the device of stored NOx, and deselects the rich, NOx-purging engine operating condition in response to the sensor output signal, preferably after an additional time delay calculated to provide sufficient excess hydrocarbons to release substantially all stored NOx from the downstream brick.

Abstract: The invention provides a deterioration detector for an exhaust gas sensor capable of detecting an amount of change with age of an internal resistance and conducting deterioration judgment taking into consideration fluctuation between products and temperature dependency of the internal resistance of the exhaust gas sensor.

Abstract: An oxygen storage amount of a catalyst is estimated by a controller in accordance with a sensed air-fuel ratio of an inflowing exhaust gas mixture flowing into the catalyst, and a sensed intake air amount of the engine, to control the air-fuel ratio of the engine. The estimated oxygen storage amount is corrected to reduce an error in computing the estimated oxygen storage amount when a downstream exhaust condition sensed by an exhaust sensor disposed on the downstream of the catalyst becomes equal to a predetermined threshold, which is modified in accordance with the intake air amount for better emission control performance.

Abstract: A method of initializing the catalyst converter for monitoring the conversion efficiencies of a catalytic converter by measuring the oxygen storage capacity (OSC) of the converter. The measurement of the OSC indicates the degree of health of the converter. Under the same engine running conditions, the greater the OSC measurement, the healthier the converter. The catalyst needs to be set to either a rich state or a lean state prior to the measurement of its OSC time. This process is called catalyst state initialization. The catalyst has to be fully saturated from test to test in order to make consistent OSC measurements. This is through open loop fuel control by commanding a lean air to fuel ratio and then monitoring thepost-O2 sensor voltage until it falls below a calibrated value (e.g. 80 mV) indicating a lean state. The system continues to command a lean air to fuel ratio (e.g. 6%) for a calibrated duration of time (e.g.

Abstract: The temperature of an exhaust gas flowing through an exhaust passage 3 is estimated or detected, and the temperature of an active element of an exhaust gas sensor 8 (O2 sensor) is controlled at a predetermined target temperature by a heater using the estimated or detected temperature of the exhaust gas. For estimating the temperature of the exhaust gas in the vicinity of the exhaust gas sensor 8, the exhaust passage 3 extending up to the exhaust gas sensor 8 is divided into a plurality of partial exhaust passageways 3a through 3d, the temperatures of the exhaust gas in the partial exhaust passageways 3a through 3d are estimated successively from an exhaust port 2 of an engine 1. The temperature of the exhaust gas is estimated according to an algorithm which takes into account a heat transfer between the exhaust gas and passage-defining members 6a, 6b, 7 which define the exhaust passage 3 and a heat radiation from the passage-defining members into the atmosphere.

Abstract: A powertrain controller of a vehicle provides fuel injection pulses based on gasoline operation. The pulse widths of the fuel injection pulses are modified with reference to air temperature, engine speed, and exhaust gas oxygen (EGO) content to control fuel injectors for an alternative fuel such as natural gas. The EGO content, based on alternative fuel operation, is detected and compared to a desired air-fuel ratio or desired fuel trims to provide error information that is used to adjust the modification of the pulse widths. In response to the error information, a neural network (as an example) dynamically adjust the pulse widths of the alternative fuel injection based on the weights of measured, detected engine speed, EGO, universal exhaust gas oxygen, or air temperatures. The engine operating on alternative fuel is provided with the proper mixture of alternative fuel and air to respond to various engine loads and meet emission standards.

Abstract: A catalyst which has an oxygen storage function is provided in the exhaust gas pipe 2 of an engine 1. The oxygen storage amount is estimated based on the output of the air/fuel ratio sensor 4 upstream of the catalyst 3. The air/fuel ratio is controlled so that the oxygen storage amount coincides with the target value. When the output of the downstream air/fuel ratio sensor 5 continuously displays a rich or a lean value for more than a determination time which is varied continuously with respect to operating conditions, deterioration in the upstream air/fuel ratio sensor 4 is detected. Thus the output of the upstream air/fuel ratio sensor 4 is corrected based on the output of the downstream air/fuel ratio sensor 5. In this manner, output fluctuations are corrected based on the deterioration of the air/fuel ratio sensor 4 upstream of the catalyst.

Abstract: A state quantity &sgr;(n) of a switching function is calculated based on a predetermined target air-fuel ratio TGABF, a detected air-fuel ratio AFSAF detected by a sensor (16), and a state equation derived from a transfer function Geng(q) of a secondary discrete system, representing the correlation between an air-fuel ratio of an air fuel mixture in a combustion chamber (1A) and the detected air-fuel ratio (S14). The air-fuel ratio is feedback corrected by applying a sliding mode control process based on the difference between the target air-fuel ratio TGABF and the detected air-fuel ratio AFSAF, and the state quantity &sgr;(n) (S14-S21). The response and robustness of the air-fuel ratio control are enhanced by using a physical model of the secondary discrete system.

Abstract: An engine control system includes an adaptive bias sub-system (100) that generates bias values for controlling the air-fuel ratio. The sub-system (100) includes an integral controller (118) that reads an error signal from a post-catalyst switching EGO sensor (112). A plurality of noise isolation integrators (122) filter any noise resulting from a particular engine operating condition (e.g. acceleration, deceleration, idling) from the integrated error signal and stores the signal in a corresponding keep-alive memory (124) as a bias value for that engine operating condition. In a preferred embodiment, the post-catalyst feedback loop includes a gated proportional controller 116 that turns on for a limited period of time after the post-catalyst switching EGO sensor (112) switches states.

Abstract: An air/fuel ratio control apparatus and method for an internal combustion engine, and an engine control unit are provided for conducting a perturbation control to maintain a satisfactory exhaust gas purification percentage irrespective of whether or not a catalyst is deteriorated, thereby improving the post-catalyst exhaust gas characteristics. The air/fuel ratio control apparatus for an internal combustion engine comprises an ECU, and a LAF sensor and an O2 sensor disposed at locations upstream and downstream of a first catalyst, respectively, in an exhaust pipe. The ECU sets a target air/fuel ratio for converging the output of the O2 sensor to a predetermined target value such that it fluctuates over a predetermined amplitude at a predetermined frequency higher when the output of the O2 sensor remains near a predetermined target value than when it is not near the predetermined target value.

Abstract: A controller for controlling an air-fuel ratio of an engine is provided. An exhaust gas sensor is provided between an upstream catalyst disposed upstream of an exhaust pipe and a downstream catalyst disposed downstream of the exhaust pipe. A virtual exhaust gas sensor is configured downstream of the downstream catalyst. After an operating state in which the air-fuel is lean is cancelled, or after a fuel cut is cancelled, an estimated output of the virtual exhaust gas sensor is estimated based on a gas amount that contributes to reduction of the upstream and downstream catalysts and a detected output of the exhaust gas sensor provided between the upstream and downstream catalysts. The air-fuel ratio of the engine is controlled in accordance with the estimated output of the virtual exhaust gas sensor. Thus, the catalyst converter is appropriately reduced in accordance with a load of the engine and a state of the catalyst.

Abstract: A method for determining the efficiency of a three-way catalyst is presented. It is shown that more accurate results are achieved if the efficiency estimates are performed when the engine is at idle or during low load operating conditions. The efficiency is inferred from the amount of fuel required to purge the device after it has been fully saturated with oxidants due to lean operation. Due to improved accuracy and reduced reductant waste, this method allows for improved emission control and fuel efficiency.

Abstract: An intermediate target value calculating unit calculates an intermediate target value &phgr;midtg(i) on the basis of an output &phgr;(i−1) of an A/F ratio sensor in computation of last time and a final target value &phgr;tg(i). By the computation, the intermediate target value &phgr;midtg(i) is set between the output &phgr;(i−1) of the A/F ratio sensor in computation of last time and the final target value &phgr;tg(i). A correction amount calculating unit calculates a correction amount AFcomp(i) of the target A/F ratio on the basis of a deviation &Dgr;&phgr;(i) between the intermediate target value &phgr;midtg(i) and the output &phgr;(i) of the A/F ratio sensor. Consequently, the control is hard to be influenced by variations in waste time of the subject to be controlled and an error in modeling. While maintaining the stability of the A/F ratio feedback control, higher gain can be achieved and robustness can be also increased.

Abstract: A control apparatus is provided for eliminating a slippage in control timing between the input/output of a controlled object, even when the control object exhibits a relatively large dynamic characteristic such as a phase delay, a dead time, or the like, to improve the stability and the controllability of the control. The control apparatus comprises a state predictor for calculating a predicted value of a value indicative of an output of a controlled object based on a prediction algorithm, and a DSM controller for calculating a control input to the controlled object based on one modulation algorithm selected from a &Dgr; modulation algorithm, a &Dgr;&Sgr; modulation algorithm, and a &Sgr;&Dgr; modulation algorithm for controlling the output of the controlled object in accordance with the calculated predicted value.

Abstract: The present invention is constituted so that an actual air-fuel ratio is detected by an air-fuel ratio sensor, a plant model representing a plant between a fuel injection valve and the air-fuel ratio sensor is sequentially identified to calculate parameters of the plant model, a control gain for calculating a feedback control amount is calculated using the calculated parameters, and the feedback control amount is calculated using the calculated control gain, wherein an absolute value of an input side parameter set on an input side of the plant model is limited to be a predetermined limit value or above, among the calculated parameters.

Abstract: The present invention is constituted so that an actual air-fuel ratio is detected by an exhaust state by an air-fuel ratio sensor, parameters of transfer functions are calculated while sequentially identifying a plant model representing a plant between a fuel injection valve and the air-fuel ratio sensor by the transfer functions, a feedback control amount of said air-fuel ratio control signal is set using the parameters of the identified pant model, an offset correction amount of the air-fuel ratio control signal is set, and the plant model is identified using a valve obtained by adding the offset correction amount to the feedback control amount, and the actual air-fuel ratio.

Abstract: For a three-way catalytic converter system with a preliminary catalytic converter, a main catalytic converter and an oxygen sensor with a constant characteristic curve disposed between the two catalytic converters, a method for resetting the oxygen concentration in the preliminary catalytic converter and the main catalytic converter in the event of a transition from lean-burn operation to stoichiometric operation includes exposing both catalytic converters to a rich mix until the desired oxygen concentrations have been reached. In the process, the constant measurement signal from the oxygen sensor and the measurement signal from an air mass flow meter are used to calculate the quantity of oxygen that is released to the exhaust gas from the main catalytic converter, in order to end rich-burn operation when a predetermined desired value is reached.

Abstract: A method for controlling air-fuel ratio of an engine coupled to an emission control device uses an upstream linear exhaust gas sensor and a switching downstream exhaust gas sensor. During stoichiometric operation, both sensors are used for feedback control. During operation away from stoichiometry, the downstream sensor feedback is disabled.

Abstract: A fuel supply control system for an internal combustion engine wherein a basic fuel amount supplied to said engine can be calculated according to the intake air flow rate detected by said intake air flow rate sensor. An air-fuel ratio correction coefficient can be calculated for correcting an amount of fuel to be supplied to the engine so that the detected air-fuel ratio coincides with a target air-fuel ratio. At least one correlation parameter vector which defines a correlation between the air-fuel ratio correction coefficient and the intake air flow rate detected by the intake air flow sensor, can be calculated using a sequential statistical processing algorithm. A learning correction coefficient relating to a change in characteristics of the intake air flow rate sensor can be calculated using the correlation parameter. An amount fuel to be supplied to the engine can be controlled using the basic fuel amount, the air-fuel ratio correction coefficient, and the learning correction coefficient.

Abstract: A method for controlling the phasing of first and second air/fuel ratio oscillations in first and second cylinder groups, respectively, of an internal combustion engine is provided. The method includes determining a phase difference between the first air/fuel ratio oscillations and the second air/fuel ratio oscillations. The method further includes adjusting a phase of the first air/fuel ratio oscillations so that both first and second air/fuel ratio oscillations are at a predetermined phase offset with respect to one another, while maintaining an average air/fuel bias in the first cylinder group.

Abstract: In a direct injection spark ignition engine which is operable in three operation modes including a stoichiometric air/fuel ratio operation mode, a pre-mixture combustion mode and a stratified combustion operation mode which are different in the desired air/fuel ratio and a single air/fuel ratio sensor installed downstream of the exhaust manifold, the sensor output is successively sampled and one from among the sampled data is selected based on the engine speed and engine load and selected one of the operation modes such that the air/fuel ratio at each cylinder can be accurately estimated for the selected operation mode under the engine operating conditions.

Abstract: A fuel injector (5) injects fuel to generate an air-fuel mixture that is burnt in the engine (1), and a sensor (16) detects an air-fuel ratio of the air-fuel mixture from an exhaust gas composition of the engine (1). A controller (11) calculates a dead time representing a lag between the air-fuel ratio variation of the air-fuel mixture and the air-fuel ratio variation detected by the sensor (16), and calculates an estimated state quantity by applying a dead time compensation according to Smith method and a disturbance compensation to the air-fuel ratio detected by the sensor (16). By determining an air-fuel ratio feedback correction amount based on the estimated state quantity applying a sliding mode control process, the response and stability of air-fuel ratio control is improved.

Abstract: An exhaust gas treatment system for an internal combustion engine includes a three-way catalyst and a NOx device located downstream of the three-way catalyst. The device is preconditioned for emissions reduction at engine operating conditions about stoichiometry by substantially filling the device with oxygen and NOx; and purging stored oxygen and stored NOx from only an upstream portion of the device, whereupon the upstream portion of the device operates to store oxygen and NOx during subsequent lean transients while the downstream portion of the device operates to reduce excess HC and CO during subsequent rich transients.

Abstract: An air-fuel ratio control device for an internal combustion engine is provided with: an air-fuel ratio sensor; an O2 sensor; a device for setting a reference air-fuel ratio target value; a device for setting a target value of an output value of the O2 sensor; a device for obtaining an air-fuel ratio target value correction value; a device for obtaining a forcible air-fuel ratio oscillation width target value; a device for computing an air-fuel ration target value; a device for computing a correction value; a device for obtaining a forcible air-fuel ratio oscillating width injector driving time correction value; and a device for setting injector driving time.

Abstract: A method for controlling mode transitions, such as from stratified to homogeneous mode, in a direct injection engine adjusts an intake manifold outlet control device, such as a cam timing, to rapidly control cylinder fresh charge despite manifold dynamics. In addition, a coordinated change between an intake manifold inlet control device, for example a throttle, and the outlet control device is used to achieve the rapid cylinder fresh charge control. In this way, engine torque disturbances during the mode transition are eliminated, even when cylinder air/fuel ratio is changed from one cylinder event to the next.

Abstract: A control system for a plant, having an identifier and a controller. The identifier identifies model parameters of a controlled object model which is obtained by modeling the plant. The controller calculates a control input to the plant so that an output from the plant coincides with a control target value, using the identified model parameters. The controller calculates a self-tuning control input, using the model parameters identified by the identifier. The controller further calculates a damping control input according to the rate of change in the output from the plant or the rate of change in a deviation between the output from the plant and the control target value. The controller calculates the control input to the plant as a sum of the self-tuning control input and the damping control input.

Abstract: A device for controlling the air-fuel ratio of an internal combustion engine, which is capable of highly precisely finding learning correction values in an open-loop operation region by using an ordinary air-fuel ratio sensor. The device comprises means 22 for correcting the amount of fuel depending upon a target air-fuel ratio AFo, means 23 for determining the conditions CF for controlling the air-fuel ratio feedback of the internal combustion engine depending upon the operation conditions, means 24 for controlling the air-fuel ratio feedback in the feedback operation region, and means 25 for finding learning correction values Zs for every operation region based on the control quantity AFc of the feedback control means, wherein the feedback control operation is executed in the open-loop operation region, and the learning correction values in the open-loop operation region are found during the feedback control operation that lasts only temporarily.

Abstract: An air-fuel ratio control system for an internal combustion engine estimates an oxygen storage amount of a catalyst based on a record of an oxygen storage amount, and controls an air-fuel ratio based on the estimated oxygen storage amount. The catalyst is divided into multiple sections in a flow direction of an exhaust gas, the oxygen storage amount in a specified section is estimated according to a behavior of an exhaust gas on upstream and downstream sides of the respective specified sections, and the air-fuel ratio is controlled based on the estimated oxygen storage amount in the specified section.

Abstract: An internal combustion engine (10) has a plurality of cylinders which are arranged in two cylinder banks. A sensor (131, 132) is assigned to each of the two cylinder banks for determining the composition of the exhaust gas. A control apparatus is provided with which a control factor (fr1, fr2) can be determined for each of the two cylinder banks in dependence upon the output signals generated by the two sensors (131, 132). The fuel mass (ti1, ti2), which is to be injected into the two cylinder banks, can be influenced by the control factors. The two control factors (fr1, fr2) of the two cylinder banks can be compared to each other via the control apparatus. The control apparatus can distinguish between a cylinder-bank independent fault and a cylinder-bank dependent fault in dependence upon the two control factors (fr1, fr2).

Abstract: A vehicle exhaust treatment system includes an emission control device featuring at least one upstream NOx-storing “brick,” and a downstream NOx-storing “brick” that is substantially smaller in nominal capacity than the upstream brick. An oxygen sensor positioned between the upstream and downstream bricks generates an output signal representing the concentration of oxygen in the device. A controller selects a rich operating condition to purge the device of stored NOx, and deselects the rich, NOx-purging engine operating condition in response to the sensor output signal, preferably after an additional time delay calculated to provide sufficient excess hydrocarbons to release substantially all stored NOx from the downstream brick.

Abstract: When an output signal from an oxygen sensor is within a predetermined range including a value equivalent to a stoichiometric air-fuel ratio, the output signal is converted into air-fuel ratio data, to compute an air-fuel ratio control signal based on a deviation between the air-fuel ratio data and a target air-fuel ratio. When the output signal from the oxygen sensor is outside the predetermined range, it is judged based on the output signal whether an actual air-fuel ratio is richer or leaner than the target air-fuel ratio, to compute the air-fuel ratio control signal based on the judgment result.

Abstract: A canister includes an adsorbent, an air layer and an air hole. An ECU obtains a physical status quantity Mgair representing the vapor stored state of the air layer, a physical status quantity Mgcan representing the fuel vapor stored state of the adsorbent, and a physical status quantity Fvptnk representing the vapor generating state in the fuel tank. The ECU then estimates a total vapor flow rate Fvpall purged to an intake system of the engine by using a physical model related to the vapor behaviors. The physical model is based on the obtained physical status quantities. The ECU corrects the fuel supply amount to the engine according to the estimated flow rate Fvpall. As a result, the air-fuel ratio feedback control is readily prevented from being influenced by the fuel vapor purging.

Abstract: A plurality of control object models set with different waste times, respectively, are provided, and each of the control object models is identified to compute a predicted output using the identified control object models. The predicted output and an actual output detected are compared with each other, to select the control object model in which a difference therebetween becomes minimum as a final control object model. Then, an input to the control object is feedback controlled, while estimating an output after the lapse of waste time using the selected control object model to compare the predicted output with the output detection value.

Abstract: A method for applying and controlling current applied to an air reference oxygen sensor included in a vehicle exhaust system is disclosed. In an exemplary embodiment of the invention, the method includes measuring an output voltage across the oxygen sensor when the exhaust system is initially activated and applying a current through the oxygen sensor when the output voltage reaches a value determinative of light off of a catalyst within the exhaust system. The magnitude of the applied current corresponds to a predefined purge value.

Abstract: An air-fuel ratio control apparatus of an internal combustion engine according to the present invention is provided with oxygen storage amount estimating means, downstream exhaust air-fuel ratio detecting means, maximum oxygen storage amount estimating means, and air-fuel ratio target setting means. The oxygen storage amount estimating means estimates an oxygen storage amount of an exhaust purifying catalyst, based on a history of an oxygen adsorption/desorption amount of the exhaust purifying catalyst located on an exhaust path. The downstream exhaust air-fuel ratio detecting means is located downstream of the exhaust purifying catalyst and detects an exhaust air-fuel ratio downstream of the exhaust purifying catalyst. The maximum oxygen storage amount estimating means estimates a maximum oxygen storage amount, based on an oxygen storage amount estimate when the exhaust air-fuel ratio detected is a predetermined air-fuel ratio.

Abstract: The characteristics of the output of an exhaust gas sensor with respect to the air-fuel ratio of an engine are expressed by a nonlinear function such as a quadratic function or the like, and the parameters of the nonlinear function are sequentially identified according to a sequential identifying algorithm using the data of the output of the exhaust gas sensor and the data of the output of an air-fuel ratio sensor which detects the air-fuel ratio of the engine. An air-fuel ratio at which the function value of the nonlinear function whose parameters have been identified is used as a target air-fuel ratio, and the air-fuel ratio of the engine is controlled at the target air-fuel ratio.

Abstract: There is disclosed an apparatus in which changes of linear A/F sensor or engine response characteristics can be detected with high precision in a broad range during operation of an engine. The apparatus includes a controller 50 for controlling an air/fuel ratio of each cylinder of a multiple cylinder engine, and a linear A/F sensor 28 for emitting an output which is proportional to the air/fuel ratio of an exhaust tube assembly. The air/fuel ratio of a specific cylinder is changed by a predetermined amount, a vibration component amplitude or a frequency component based on an engine rotation number is extracted from a signal obtained from the linear A/F sensor 28, and the response characteristics of an air/fuel ratio detector or the engine are detected from the amplitude or a power of the frequency component.

Abstract: A non-linear term UNL is computed as UNL=gain GNL×(air-fuel ratio detection value−target air-fuel ratio)/(|air-fuel ratio detection value−target air-fuel ratio|)+previous value UNL (OLD), and a linear term UL is computed as UL=gain GL×(air-fuel ratio detection value−target air-fuel ratio)/air-fuel ratio detection value. An addition of UNL and UL is set as an air-fuel ratio feedback correction coefficient to correct a fuel injection quantity. The gain GL is set a greater value as |air-fuel ratio detection value−target air-fuel ratio| becomes greater.

Abstract: Before starting an air-fuel ratio feedback control utilizing an air-fuel ratio sensor, activation of a wide-range air-fuel ratio sensor in an internal combustion engine is diagnosed by calculating heat transferred to and from the air-fuel ratio sensor, the output value of the wide-range air-fuel ratio sensor varies in response to oxygen concentration in exhaust which varies according to the air-fuel ratio of an intake air-fuel mixture of the internal combustion engine. The activation time from the starting of the engine until the air-fuel ratio sensor is activated is estimate based on the calculated result of the heat transfer. Alternatively, activation of the sensor is diagnosed under the condition that an output voltage of the oxygen concentration detecting unit of the sensor is fixed to a value either equal to or above a rich-side set voltage or equal to or under a lean-side set voltage, before starting the air-fuel ratio feedback control.

Abstract: In a sliding mode control for restraining an air-fuel ratio state on a switching line set on a phase plane shown by a deviation between an actual air-fuel ratio and a target air fuel ratio, and a differential value of the deviation, an inclination of the switching line is made small, when the smaller an intake air quantity is, the longer a detection delay time of the air-fuel ratio is.

Abstract: In an air-fuel ratio feedback control of an internal combustion engine aimed to approximate an air-fuel ratio to a target air-fuel ratio set according to operating conditions of the engine, the feedback control is carried out using the feedback control amount which is computed according to a sliding mode control, having a deviation between the target air-fuel ratio and the detected air-fuel ratio detected by the air-fuel ratio sensor set as a switching function. According to the present invention, a simple air-fuel ratio feedback control is carried out according to an accurate sliding mode control with no dispersion for each engine, that is easy to design, and that can be applied generally to any kind of vehicle or engine.

Abstract: In an engine capable of continuously controlling an intake air quantity by varying an intake valve operating characteristic, an intake valve lift is sensed as well as an engine speed. Then, an intake air quantity is calculated in accordance with the engine speed and intake valve lift when an engine operating point is in a very low lift state.

Abstract: This invention is a method and system for a hybrid electric vehicle adaptive fuel strategy to quickly mature an adaptive fuel table. The strategy adaptively alters the amount of fuel delivered to an internal combustion engine to optimize engine efficiency and emissions using engine sensors. Before the adaptive fuel strategy is permitted, an engine “on” idle arbitration logic requires the HEV to be in idle conditions, with normal battery state of charge, normal vacuum in the climate control and brake system reservoir; and, the vapor canister not needing purging. The strategy orders the engine throttle to sweep different airflow regions of the engine to adapt cells within the adaptive fuel table. In the preferred configuration, a generator attached to the vehicle drive train, adds and subtracts torque to maintain constant engine speed during the throttle sweeps.

Abstract: A method for estimating pressure surround an engine uses a gauge pressure sensor upstream of an orifice and an absolute pressure sensor downstream of the orifice. In particular, atmospheric pressure can be determined when flow through the orifice is below a predetermined threshold.

Abstract: In a control apparatus for use in an internal combustion engine which has an exhaust gas sensor adapted to detect exhaust gas components and provide an output deliver to an air-fuel ratio of mixture and which performs stratified charge combustion, signals for controlling the air-fuel ratio of mixture and the fuel injection timing are generated on the basis of the output of the exhaust gas sensor. When an optimal air-fuel ratio responsible for combustion stability is changed as a result of execution of EGR and evaporative fuel purging, a change of the air-fuel ratio is determined by using the output of the exhaust gas sensor. When the influence of the EGR or the evaporative fuel purging upon the air-fuel ratio is great, the air-fuel ratio is corrected and the fuel injection timing or the ignition timing is corrected.

Abstract: A method and a device for controlling operational sequences, particularly in a vehicle, at least one sensor having a connection unit being connected via a bus system to at least one control unit for controlling the operational sequences, the control unit likewise having a connection unit, and sensor information being transmitted to the control unit. The control unit reads in and/or processes the sensor information at specifiable synchronization points. A trigger signal is transmitted by the control unit via the bus system to the sensor in such a way with an allowance that the sensor information is available in a manner that it is able to be read in and/or processed exactly at the synchronization point for the control unit.

Abstract: The invention concerns a method for automatic adaptation of an injection engine by a computer connected to sensors. The sensors supply an engine filling parameter. An oxygen probe in the exhaust gases, defines, at each adapting cycle, a new line of control magnitude based on the filling parameter and using new coefficients computed from coordinates of two points. Corresponding corrected values of the control magnitude from a working line are filtered and stored during a preceding cycle. One of the two points is acquired previously, and then in adopting a new working line, an intermediate line between the new line and the previous working line is used. The invention is applicable to injection engine control.

Abstract: There is provided a fuel supply control system for an internal combustion engine, which is capable of controlling fuel cutoff according to an amount of oxygen stored in a catalytic converter to thereby enhance the purification rate of the catalytic converter while maintaining excellent fuel economy, thereby making it possible to improve exhaust emission characteristics. An amount of oxygen stored in the catalytic converter 13 arranged in an exhaust pipe 12 of an engine 3 is estimated (steps S1 to S29). A deceleration condition of the engine is detected (steps S35, S36). When the deceleration condition is detected, supply of fuel to the engine is cut off (step S41). The cutoff of fuel supply is controlled based on the oxygen storage amount OSC (steps S31, S32, S40, S41).

Abstract: A data estimation capability using a FNN to estimate engine state data for an engine control system is described. The data estimation capability provides for making data relating to the engine state available as control parameters in a simple, inexpensive manner. The data estimation includes using data from one or more sensors as inputs to a FNN to estimate unmeasured engine operating states. The data estimates are provided as control parameters to an engine control system. The FNN can be used to provide data estimates for engine state values (e.g. the exhaust air fuel ratio, the exhaust NOx. value, the combustion chamber temperature, etc.) that are too difficult or too expensive to measure directly. Each FNN can be configured using a genetic optimizer to select the input data used by the FNN and the coupling weights in the FNN.

Abstract: An internal combustion engine is simulated as a control model that covers from a fuel injection point to an air-fuel ratio detection point. A response time constant of the control model is calculated as a continuous function of the amount of intake air, and a control gain of the control model is calculated as a continuous function of the response time constant. Control parameters of the control model are calculated using a calculation interval, the response time constant, an attenuation coefficient and the control gain. Thus, the control parameters are varied continuously in response to changes in the intake air amount. The air-fuel correction coefficient is calculated using the control parameters a0, a1, a2, b1 and b2 as well as a deviation of an actual air-fuel ratio from a target air-fuel ratio. The amount of fuel supplied to the engine is calculated using the air-fuel ratio correction coefficient.