By calculating a throttle opening learning value based on an actual effective opening area calculated based on the actual flow rate of intake air and an actual throttle opening with respect to variations caused by type differences of throttle valves and by calculating a throttle opening learning completion range indicating the region for which throttle opening learning completion has been determined based on the state of deviation between an effective opening area corrected by throttle opening learning and the actual effective opening area, control that applies the throttle opening learning value or fail-safe of an air flow sensor is performed in a contiguous throttle opening learning completion range.

In a control device for an internal combustion engine, a learning map includes at least one partitioned operating region. The at least one partitioned operating region corresponds to at least one of operating conditions of the internal combustion engine. The learning map includes a value of at least one control parameter stored in the at least one partitioned operating region. A control unit controls the internal combustion engine in accordance with the at least one control parameter. An updating unit learns a value of the at least one control parameter for the at least one of the operating conditions, thus performing an updating of the value of the at least one control parameter stored in the at least one partitioned operating region to the learned value. A partition changing unit changes a partition pattern of the learning map.

The subject matter of this specification can be embodied in, among other things, a method for characterizing a fluid injector that includes receiving a collection of waveform data, identifying a pull locus, determining a detection threshold level value, identifying a first subset of the collection of data representative of a selected first electrical waveform of the collection of electrical waveforms, identifying an opening value, identifying a representative closing value, identifying an anchor value, identifying a second subset of the collection of data based on the collection of data, the pull locus, the first subset, and the opening value, identifying a maximum electrical value, identifying an opening locus based the collection of data, the anchor value, and the maximum electrical value, identifying a hold value, and providing characteristics associated with the fluid injector comprising the pull locus, the opening locus, the hold value, the anchor value, and the representative closing value.

An ECU calculates a cylinder flowing air amount based on an intake tube pressure, using an air intake valve model simulating a behavior of air flowing into a combustion chamber via an air intake valve. The ECU calculates an air intake amount based on a detection result of an air amount detection sensor, and determines whether the air intake amount matches an actual amount of air flowing into the combustion chamber. When the air intake amount is determined to match the actual amount, the ECU calculates a learnt value based on comparison of the cylinder flowing air amount with the air intake amount.

When executing a Local-learning, an air-fuel ratio detecting time is corrected so that a dispersion of detection values of an air-fuel ratio sensor becomes a maximum value in one cycle of an engine. While executing a cylinder-by-cylinder air-fuel ratio control, a Global-learning is executed. In the Global-learning, the air-fuel ratio detecting time is corrected based on a relationship between a variation in estimated air fuel ratio of each cylinder and a variation in fuel quantity correction value of each cylinder. In the Global-learning, a computer computes a correlation coefficient between the variation in estimated air-fuel ratio and the variation in fuel quantity correction value of the cylinder for each case where the cylinder assumed to correspond to the estimated air fuel ratio is hypothetically varied in multiple ways. Then, the air-fuel ratio detecting time is corrected so that this correlation coefficient becomes a maximum value.

A method and a system for detection of torque deviations of an engine (101) in a vehicle (100). A measurement (201) is made of actual measured values D.sub.act related to a behavior of at least one parameter which is related to an actual torque M.sub.eng.sub._.sub.act delivered by the engine (101). This actual torque M.sub.eng.sub._.sub.act is delivered here by the engine (101) in consequence of a torque M.sub.eng.sub._.sub.req demanded from the engine (101). A comparison (202) is then made of the actual measured values D.sub.act which are related to the behavior of the at least one parameter with previously determined measured values D.sub.ref of correspondingly at least one respective parameter related to the actual torque M.sub.eng.sub._.sub.act. The previously determined measured values D.sub.ref will here have been determined during normal operation of the vehicle (100). Detection is then made of whether the actual measured actual torque M.sub.eng.sub._.sub.act deviates from the demanded torque M.sub.engj-eq. The detection is based here on the comparison of the actual measured values D.sub.act with the previously determined measured values D.sub.ref.

A controller for an internal combustion engine includes a detector and a processor. The detector detects a combustion condition of a gas in a cylinder of the internal combustion engine. The processor is configured to calculate a fuel ratio in the gas in the cylinder. The processor is configured to calculate a target combustion condition according to the fuel ratio. The processor is configured to calculate an ignition timing such that the combustion condition detected by the detector becomes equal to the target combustion condition.

Methods and systems are provided for cleaning a fuel vapor storage canister positioned in an evaporative emissions control system of a vehicle. In one example, a method comprises sealing a fuel system of the vehicle for descending an altitude change that is predicted in advance, and subsequent to the vehicle descending the altitude change, unsealing the fuel system to passively purge fuel vapors stored in the fuel vapor storage canister to a fuel tank of the vehicle. In this way, bleed through emissions from the fuel vapor storage canister may be reduced, and engine operation may be improved.

A fuel injection control device learns a port injection learning value and a direct injection learning value separately for each of learning regions that are divided according to the engine operating state. It is assumed that a port injection learning condition and a direct injection learning condition are both satisfied in a learning region in which neither the learning of the port injection learning value nor the learning of the direct injection learning value has been completed. In such a situation, the fuel injection control device executes the port injection learning process if the ratio of the port injection amount is less than the ratio of the direct injection amount, and executes the direct injection learning process if the ratio of the direct injection amount is less than the ratio of the port injection amount.

A control apparatus for an internal combustion engine is configured, during a slightly stratified-charge lean-burn operation, to: calculate a basic total fuel injection amount based on a required torque; calculate a compression stroke injection amount based on an ignition delay index value; calculate, as a basic main injection amount, a value obtained by subtracting a compression stroke injection amount from the basic total fuel injection amount; calculate, based on an output value of an in-cylinder pressure sensor, an actual specified combustion index value that represents a main combustion speed or a combustion fluctuation rate; calculate a main injection correction term based on a result of a comparison between a target specified combustion index value or a tolerable specified combustion index value, and the actual specified combustion index value; and calculate a main injection amount by adding the main injection correction term to the basic main injection amount.