A spark ignited internal combustion engine is controlled in response to a self-learned TOB reference. The self-learned TOB reference is based on a difference between a learned TOB offset and a desired or target TOB, and a sensed TOB. The learned TOB offset at a given operating condition, such as charge pressure, can be found by interpolating between the learned charge pressure breakpoints in a TOB learning algorithm. The TOB learning algorithm can include using a filtered charge pressure value to indicate the engine load at which the TOB is learned. An index determination is made with a look up table with charge pressure as an input and an array index of learned charge pressure and learned TOB offset as outputs.

A fuel combustion apparatus 2 according to the present invention includes: a combustion cylinder 4; a fuel feed unit 6 that introduces a swirling flow of an air-fuel mixture into the combustion cylinder; an ignition unit 10 including an igniter 32 located in the combustion cylinder 4; an ion detection unit 12 including a detector 40 located in the combustion cylinder 4; and a control unit 14 that adjusts a mixing ratio of the fuel based on a detection result obtained by the ion detection unit 12. Preferably, the fuel is ammonia. Preferably, the detector 40 is located in the vicinity of the igniter 32.

System for controlling an engine provided with an exhaust gas post-treatment system of the selective catalysis type, including a closed-loop control of NO.sub.x before the gas post-treatment system, according to the following steps: ⋅ a unit for determining a NO.sub.x setpoint in dependence on the rotational speed and the torque setpoint of the engine, ⋅ a unit for determining a NO value, and ⋅ a cascade control unit which is able to determine a setpoint for admitted oxygen and a correction of the supercharging pressure destined for unit for controlling the air loop of the engine as well as a correction of the injection pressure and a correction of the advance of the main injection in dependence on a NO.sub.x difference, between a NOx emission setpoint or corrected emission setpoint and a determined value of the quantity of NO.sub.x.

A system for controlling emissions of a motor-vehicle spark-ignition internal combustion engine includes first and second exhaust gas treatment devices and a secondary air feeding system for feeding secondary air into an exhaust gas conduit, between the first and second exhaust gas treatment devices. The secondary air feeding system is activated only when engine load is greater than a predetermined load value and/or when engine rotational speed is greater than a predetermined speed value. In this condition, an air/fuel ratio of the engine is kept at a value lower than the stoichiometric value, so as to feed the engine with a rich mixture. In one example, an electronic controller is configured for controlling activation of the secondary air feeding system on the basis of a map, as a function of values of the engine load and rotational speed. The map is predetermined depending upon specific characteristics of the engine.

The invention relates to a control method that allows the mean quantity of nitrogen oxides per kilometer covered emitted by a vehicle fitted with an internal combustion engine associated with a post-treatment system to be kept below a predefined fixed threshold, for any journey made by the vehicle. The mean quantity emitted over a fixed elementary distance that has just been covered by the vehicle is calculated iteratively, together with a long-term conformity factor which is equal to the mean quantity emitted over the entire distance covered since the start of the journey. When it is found that the long-term conformity factor is above the threshold, the engine and/or the post-treatment system is regulated in such a way as to obtain, over the next fixed elementary distance, a mean quantity of nitrogen oxides per kilometer that is lower than the threshold value FC, for example equal to 90% of the threshold, whatever the engine operating point. Thus, the long-term conformity factor converges towards the threshold.

Methods and systems are provided for emissions reduction in a vehicle. In one example, a method includes pre-emptively adjusting engine operating parameters in response to an anticipated emissions causal event. The emissions causal event lasting for less than a threshold period of time or less than a threshold distance.

Various embodiments include a method for operating an internal combustion engine with a three-way catalytic converter with lambda control, comprising: monitoring a NO.sub.x sensor for a lambda value downstream of the converter; setting a threshold value determining a lambda setpoint value upstream of the converter using the difference between the setpoint value of the electrical signal and the measured electrical signal if the signal is below the threshold; if above the threshold value, determining the lambda setpoint value upstream of the converter using the difference between a NH.sub.3 setpoint value of the NO.sub.x sensor and the measured NH.sub.3 signal of the NO.sub.x sensor; and if the measured NH.sub.3 concentration is higher than the NH.sub.3 setpoint value, increasing the lambda setpoint value upstream of the converter and, if the measured NH.sub.3 concentration is lower than the NH.sub.3 setpoint value, reducing the lambda setpoint value upstream of the converter.

The invention relates to a method for operating an internal combustion engine installed in a vehicle, in particular a diesel engine, in which the instantaneous concentration of a pollutant contained in the exhaust gas, in particular the NO.sub.x concentration in the exhaust gas, is measured or calculated in the flow direction after an exhaust gas aftertreatment. Using the determined pollutant concentration, the predefined distance- and/or power-based compliance with pollutant limiting values in mg/km or mg/kWh are monitored by means of specifically influencing the operating parameters of the internal combustion engine and/or an exhaust gas after treatment system in regulated form.

An illustrative fuel delivery system for an engine can include a fuel type indicator device and a flow management device. The flow management device can be configured to receive fuel from an auxiliary fuel tank and to direct it based on the type of fuel in the auxiliary fuel tank. If the type of fuel in the auxiliary fuel tank is a primary fuel type (such as diesel or gasoline), the flow management device can deliver the primary fuel to a piston cylinder of the engine. If the type of fuel in the auxiliary fuel tank is an auxiliary fuel (such as a mixture of ethanol and water the flow management device can deliver the auxiliary fuel to an air intake system of the engine.

A spark ignited internal combustion engine is controlled in response to a self-learned TOB reference. The self-learned TOB reference is based on a difference between a learned TOB offset and a desired or target TOB, and a sensed TOB. The learned TOB offset at a given operating condition, such as charge pressure, can be found by interpolating between the learned charge pressure breakpoints in a TOB learning algorithm. The TOB learning algorithm can include using a filtered charge pressure value to indicate the engine load at which the TOB is learned. An index determination is made with a look up table with charge pressure as an input and an array index of learned charge pressure and learned TOB offset as outputs.