摘要:
A system for purifying exhaust gas generated by an internal combustion engine having an adsorbent, installed in an exhaust system of the engine, which adsorbs unburned components of the exhaust gas such as hydrocarbons generated by the engine. The system has a first temperature sensor for detecting a temperature of the adsorbent and timer for measuring a time until the detected temperature becomes greater or equal to a predetermined value, when the measured time is less than a threshold value, it is discriminated that the adsorbent deteriorates. With this, the deterioration of the adsorbent can be discriminated accurately.
摘要:
A first exhaust gas sensor 5 (air-fuel ratio sensor) and a second exhaust gas sensor 6 (O2 sensor) are disposed respectively upstream and downstream of a catalytic converter. An exhaust system E which ranges from the exhaust gas sensor 5 to the exhaust gas sensor 6 and includes the catalytic converter 3 is regarded as an object exhaust system E, and a behavior of the object exhaust system E is modeled. When an internal combustion engine 1 is in operation, parameters to be set of the model of the object exhaust system E are sequentially identified based on the data of outputs of the exhaust gas sensors 5, 6. A deteriorated state of the catalytic converter 3 is determined based on the data of the identified values. Concurrent with the determination of the deteriorated state, a target air-fuel ratio for the internal combustion engine 1 is sequentially determined in order to converge the output of the exhaust gas sensor 5 to a given target value, and the air-fuel ratio of the internal combustion engine 1 is controlled to converge the output (the detected value of the air-fuel ratio) of the first exhaust gas sensor 5 to the target air-fuel ratio, for thereby allowing the catalytic converter 3 to achieve an optimum purifying capability. In this manner, the deteriorated state of the catalytic converter 3 can be determined in various operation states of the internal combustion engine 1 while keeping the purifying capability of the catalytic converter 3.
摘要:
A control system for controlling an internal combustion engine which discharge exhaust gases through an emission purifier includes a controller which increases the quantity of intake air drawn into the internal combustion engine while the internal combustion engine is idling after the internal combustion engine has started to operate, to a level which is greater by a predetermined increase than the quantity of intake air drawn into the internal combustion engine while the internal combustion engine is idling normally. The controller also generates a command value for ignition timing of the internal combustion engine according to a feedback control process to converge the rotational speed of the internal combustion engine toward a predetermined target rotational speed, and controlling the ignition timing of the internal combustion engine based on the generated command value thereby to retard the ignition timing. The controller establishes the target rotational speed by changing the target rotational speed from a preset rotational speed toward a predetermined idling speed after the rotational speed of the internal combustion engine has reached the preset rotational speed which is higher than the idling speed after the quantity of intake air drawn into the internal combustion engine has started being increased.
摘要:
A catalyst state detector for detecting a state of an exhaust gas purifying catalyst which is capable of accurately detecting the state, including deterioration, of an HC adsorbent contained in the exhaust gas purifying catalyst for adsorbing hydrocarbons in exhaust gases of an internal combustion engine, and can be manufactured at a low cost. The exhaust gas purifying catalyst is arranged at an intermediate portion of an exhaust pipe, and the HC adsorbent is capable of adsorbing hydrocarbons and moisture in exhaust gases. The catalyst state detector comprises a downstream humidity sensor arranged at a location downstream of the HC adsorbent in the exhaust pipe for detecting a humidity of the exhaust gases, and an adsorbent state detecting unit (ECU) for detecting the state of the HC adsorbent in accordance with the result of detection made by the downstream humidity sensor.
摘要:
There are provided an adsorption amount sensor which is capable of accurately detecting an amount of hydrocarbons or water adsorbed by a zeolite of a hydrocarbon adsorber, even during operation of an engine, as well as a coking sensor which is capable of accurately detecting an amount of coke deposition on inner surfaces of a pipe of an internal combustion engine, even during operation of an engine. The adsorption amount sensor has a plurality of electrodes arranged in the vicinity of the hydrocarbon adsorber in a manner opposed to each other and each carrying a zeolite thereon. The amount of hydrocarbons adsorbed is detected by using a parameter indicative of changes in at least one of a resistance value between the electrodes and an electrical capacitance between the electrodes. The coking sensor has a plurality of electrodes arranged within the pipe of the engine in a manner opposed to each other and each having a surface thereof coated with an insulating material. The amount of coke deposition is detected by using a parameter indicative of changes in at least one of a resistance value between the electrodes and an electrical capacitance between the electrodes.
摘要:
An adsorbent state determining apparatus is provided for accurately determining the state of an adsorbent including a deterioration as well as for allowing for recovery of the adsorbent if its adsorbent performance can be restored. The adsorbent state determining apparatus determines the state of an adsorbent for adsorbing hydrocarbons contained in exhaust gases. An upstream and a downstream temperature sensor are provided at upstream and downstream locations of the adsorbent in an exhaust system for detecting temperatures of exhaust gases upstream and downstream of the adsorbent. An engine water temperature sensor detects an operating state of the engine. An ECU estimates the temperature of the exhaust gas which should be detected downstream of the adsorbent during adsorption of the adsorbent based on the upstream temperature detected by the upstream temperature sensor and an engine water temperature of the engine detected by the engine water temperature sensor. The ECU then compares the estimated downstream temperature with the detected downstream temperature detected by the downstream temperature sensor during adsorption of the adsorbent to determine the adsorption state of the adsorbent.
摘要:
An allowable range (adaptive allowable range) for limiting a manipulated variable generated in order to converge the difference between an output from an O2 sensor disposed downstream of a catalytic converter and a target value thereof to “0” is sequentially updated depending on how the manipulated variable deviates from the allowable range.
摘要:
A plant control system has a reference value setting unit for variably setting a reference value for an air-fuel ratio to be given to an exhaust system including a catalytic converter, depending on a component based on an adaptive control law of a manipulated variable of the air-fuel ratio generated by a controller according to an adaptive sliding mode control process in order to converge an output of an O2 sensor disposed downstream of the catalytic converter to a target value. The manipulated variable generated by the controller represents the difference between the air-fuel ratio and the reference value, required to converge the output of the O2 sensor to the target value.
摘要:
An object system for generating an output signal of an O2 sensor from a target air-fuel ratio is expressed as a model including a response delay element and a dead time element. Data of identified values of parameters of the model are sequentially generated by an identifier. Data of an estimated value of the output signal of the O2 sensor after a dead time of the object system is sequentially generated by an estimator. The target air-fuel ratio is generated according to an adaptive sliding mode control process performed by a sliding mode controller using the data of the identified and estimated values. The air-fuel ratio of an internal combustion engine is manipulated on the basis of the target air-fuel ratio according to a feed-forward control process.
摘要:
A control system for an internal combustion engine having an exhaust system, an intake system, and an exhaust gas recirculation mechanism for recirculating exhaust gases from the exhaust system to the intake system is disclosed. The exhaust system is provided with an adsorbent for adsorbing hydrocarbon. When the adsorbent has adsorbed the hydrocarbon and the engine is operating in an idling condition, an intake air amount of the engine is increased and an ignition timing of said engine is retarded, and at the same time, the exhaust gas recirculation is performed to recirculate the hydrocarbon desorbed from the adsorbent to the intake system.