Abstract: The present invention reduces the load on a user when performing remote machine diagnosis. An acquisition unit (11) acquires time-series data obtained from equipment of the machine, a prediction unit (12) predicts the state of the machine on the basis of the time-series data, a search unit (13) uses the time-series data as a query to search a knowledge database, storing records of past diagnoses, for knowledge information related to the state of the machine, and a provision unit (14) provides the prediction result and the knowledge information.

Abstract: A inject gas control device that performs, for example, control reflecting variation in vessel velocity over time without adversely affecting the main engine is realized. That is, it is prevented that gas is drawn too much and thereby a gas supply or charged air rate becomes insufficient, efficiency of the main engine is decreased and exhaust gas is deteriorated, and analogous events occur because the gas supply or charged air rate is too much instead. There are provided a main engine 4010 acquiring propelling power for a vessel 1, and a turbocharger 4011 that is driven by exhaust gas from the main engine 4010 and blows pressurized gas to the main engine 4010. A part of the pressurized gas and/or exhaust gas is drawn from between the turbocharger 4011 and the main engine 4010 (5023, 5024 and 5025).

Abstract: A inject gas control device that performs, for example, control reflecting variation in vessel velocity over time without adversely affecting the main engine is realized. That is, it is prevented that gas is drawn too much and thereby a gas supply or charged air rate becomes insufficient, efficiency of the main engine is decreased and exhaust gas is deteriorated, and analogous events occur because the gas supply or charged air rate is too much instead. There are provided a main engine 4010 acquiring propelling power for a vessel 1, and a turbocharger 4011 that is driven by exhaust gas from the main engine 4010 and blows pressurized gas to the main engine 4010. A part of the pressurized gas and/or exhaust gas is drawn from between the turbocharger 4011 and the main engine 4010 (5023, 5024 and 5025).

Abstract: An apparatus for controlling an internal combustion engine having an exhaust purifying catalytic device which absorbs nitrogen oxides contained in exhaust when the engine is in a lean-combustion mode and which deoxidizes the absorbed nitrogen oxides when the engine is in a rich-combustion mode. The engine control apparatus includes an electronic control unit for estimating the amount of purifying capability reducing substances other than nitrogen oxides, which decreases the nitrogen oxide adsorbing ability of the catalytic device, absorbed by the catalytic device, on the basis of the accumulated value of vehicle travel distance, fuel consumption of engine, or intake air amount. The control unit changes the operating condition of engine so that the exhaust gas temperature is increased when it is judged that the estimated adsorption amount has reached a predetermined adsorption amount.

Abstract: An air-fuel ratio control system compares an air-fuel ratio indicated by air-fuel ratio information from an air-fuel ratio sensor and a target air-fuel ratio determined depending on operating conditions of a motor vehicle which incorporates the air-fuel ratio control system, for reliably determining at least a failure of the air-fuel ratio sensor. When a failure of the air-fuel ratio sensor is detected, an air-fuel ratio feedback control process is stopped or the air-fuel ratio sensor is disabled, preventing the air-fuel ratio from being corrected in error based on an output signal from the air-fuel ratio sensor which has failed. Therefore, the air-fuel ratio control system prevents problems such as poor exhaust gas purification, reduced drivability, and unstable engine idling from taking place.

Abstract: A method of and an apparatus for controlling the air fuel ratio of an internal combustion engine by which the air fuel ratio can be controlled so that the exhaust gas purifying efficiency of a catalytic converter for purifying exhaust gas of the engine may be maximum. In the apparatus, exhaust gas of the engine is first passed through a catalytic converter and then is introduced into an oxygen concentration sensor of the .lambda. type. When the air fuel ratio is compulsorily varied, the compulsorily varied condition of the air fuel ratio such as an average of variations of the air fuel ratio (average air fuel ratio) is corrected in accordance with an output of the oxygen concentration sensor thereby to control the air fuel ratio so that the purifying efficiency of the exhaust gas purifying catalytic converter may be maximum.

Abstract: A feedback control system for an air-fuel ratio according to the present invention comprises a first oxygen sensor for detecting the oxygen concentration of exhaust gas flowing through a first exhaust pipe of an internal combustion engine, a second oxygen sensor for detecting the oxygen concentration of the exhaust gas passed through an exhaust gas disposer in a common exhaust passage which is connected with both first and second exhaust pipes of the engine, and an electronic control unit for calculating the amount of fuel supply to each cylinder of the engine in accordance with the oxygen concentration of the exhaust gas detected by means of the first oxygen sensor. The electronic control unit contains therein a correction circuit for correcting the amount of fuel supply to that cylinder of the engine which is associated with the second exhaust pipe, in accordance with the oxygen concentration of the exhaust gas detected by means of the second oxygen sensor.

Abstract: An apparatus is provided for controlling the air/fuel ratio of an internal combustion engine. The apparatus includes a sensor disposed in an exhaust system for detecting components of exhaust gas, a device for compulsorily changing the air/fuel ratio, another device for setting a first target value which gives a target air/fuel ratio to be compared with each output from the sensor, and a further device for controlling the air/fuel ratio, which has been compulsorily changed by the air/fuel ratio changing device, on the basis of the result of a comparison between the output and the first target value, whereby the average air/fuel ratio may be controlled to the first target air/fuel ratio. The first target value setting device includes an element for modifying the first target value to a second target value, which gives a leaner air/fuel ratio, in a specific operation state of the engine.

Abstract: An air/fuel ratio control system is provided for an internal combustion engine. The system includes first and second oxygen density sensors, an air/fuel ratio control device and a standard-value changing device. The first oxygen density sensor is arranged on an upstream side of a catalytic converter, while the second oxygen density sensor is provided either inside or on a downstream side of the catalytic converter. The air/fuel control device controls the air/fuel ratio of the internal combustion engine on the basis of results of comparison between a detection value from one of the first and second oxygen density sensors and a predetermined standard value. The standard-value changing device changes the standard value on the basis of outputs from the first and second oxygen density sensors.