The variable compression ratio internal combustion engine 1 comprises: a variable compression ratio mechanism 6 able to change a mechanical compression ratio; an exhaust promotion mechanism 50, 55 able to reduce cylinder residual gas after an exhaust stroke of cylinders; and a control device 80 configured to control the mechanical compression ratio by the variable compression ratio mechanism and control an operation of the exhaust promotion mechanism. The control device is configured to operate the exhaust promotion mechanism in at least a partial time period of a time period from when it is demanded that the mechanical compression ratio be raised to when the mechanical compression ratio finishes being changed.

To provide a controller and a control method for internal combustion engine which can reduce arithmetic load, while suppressing deterioration in the estimation accuracy of the parameter relevant to the combustion state, even if the error component of high frequency is included in the crank angle acceleration. A controller for internal combustion engine, by referring an unburning condition data, calculates a shaft torque in unburning in the vicinity of the top dead center in the burning condition; calculates an external load torque based on calculated shaft torque in unburning and the actual shaft torque in burning in the vicinity of the top dead center; calculates a shaft torque in unburning by referring the unburning condition data; calculates an increment of gas pressure torque by burning based on the shaft torque in unburning, the actual shaft torque in burning, and the external load torque.

Methods and systems are described for combustion engine mode optimization. The system includes a combustion engine, a fuel delivery system, and a controller communicatively coupled to the combustion engine and the fuel delivery system. The controller selects a low temperature combustion mode based on the combustion engine being warmer than a predetermined temperature and low load conditions on the combustion engine. The low temperature combustion mode includes instructions that reduces an intake valve opening duration and an exhaust valve opening duration. The controller reduces the intake valve opening duration and the exhaust valve opening duration to create a delay between an intake valve opening duration and an exhaust valve opening duration in response to selecting the low temperature combustion mode. The delay increases a residual gas temperature in the combustion chamber and induces auto-ignition of fuel in the combustion chamber.

Systems and methods for operating an engine and controlling engine parameters over a range of ambient temperature conditions are provided. A method for an engine includes selecting one or more of an engine speed, an engine load, a base timing, and a fuel common rail pressure from a pre-calibrated engine map corresponding to a selected throttle level and modifying the one or more of the engine speed, the engine load, the base timing, and the fuel common rail pressure based on sensed environmental conditions.

Methods and systems are provided for fuel post injection for diesel particulate filter (DPF) regeneration. In one example, a method may include, responsive to a request for generating exotherms in an exhaust system of an engine while combustion is discontinued in at least one cylinder of the engine, injecting fuel into a cylinder within a threshold crank angle range around top dead center (TDC) of a compression stroke of the cylinder and also within the threshold crank angle range around top dead center of an exhaust stroke of the cylinder, the threshold crank angle range extending from no more than 40 crank angle degrees before TDC to no more than 40 crank angle degrees after TDC. In this way, fuel post injections may be injected +/−40 crank angle degrees after TDC of the compression and exhaust strokes to increase exhaust temperature while avoiding wall wetting and oil-in-fuel dilution.

An engine control system includes: a normalization module configured to normalize, to within a predetermined range of values, a spark timing of an engine and at least one other parameter of the engine, thereby producing a normalized spark timing and at least one normalized other parameter, respectively; a processing module configured to generate a sigmoidal spark timing by applying, to the normalized spark timing, one of (a) a sigmoidal function and a sinusoidal function; and an estimation module configured to estimate a torque output of the engine based on the normalized spark timing and the at least one normalized other parameter using a mathematical model.

An engine control system and method includes sensing the quality of fuel in the engine relative to emissions, by for example sensing the level of an emission related constituent, such as sulfur. A fuel quality sensor detects a fuel quality of a fuel, such as the sulfur level the fuel, and provides a signal in response to the fuel quality. The engine control system also includes a navigation device to determine whether an engine is located in a regulated or non-regulated region. The engine control system receives the signal and controls engine operation by, for example, enabling or disabling one or more engine algorithms to improve performance of the engine based on the fuel quality signal or, in other embodiments, the combination of the fuel quality and the location of the engine.

Method and apparatus for maintaining a speed of a vehicle within a target speed range. A plurality of coasting profiles are generated for the vehicle, each having an initial speed and a starting point on a predicted vehicle path. Each coasting profile represents a predicted vehicle speed over a time and/or distance from the starting point and is generated based on a geometry of at least a portion of the predicted vehicle path. At least one of the coasting profiles that maintains the speed of the vehicle within the target speed range is identified. A prime mover of the vehicle is controlled to place the vehicle into a coasting mode in accordance with the at least one identified coasting profile. Alternatively, feedback is provided to a user to place the vehicle into a coasting mode, such that the vehicle will coast in accordance with the at least one identified coasting profile.

Provided is an engine control device which controls at least an intake valve, an exhaust valve, and a fuel injection valve injecting a fuel into an intake pipe such that internal EGR is realized, in which timing of opening and closing of the intake valve is set to be later in comparison with a reference operation state which is a first operation state and timing of closing of the exhaust valve is set to be earlier in comparison with the reference operation state, and the fuel injection valve is caused to inject the fuel in a period which is: after a piston starts to rise which had been passed through a bottom dead center for the first time after an exhaust stroke is finished, which is followed by closing of the intake valve; and before the intake valve is opened.

An engine control system includes: a normalization module configured to normalize, to within a predetermined range of values, a spark timing of an engine and at least one other parameter of the engine, thereby producing a normalized spark timing and at least one normalized other parameter, respectively; a processing module configured to generate a sigmoidal spark timing by applying, to the normalized spark timing, one of (a) a sigmoidal function and a sinusoidal function; and an estimation module configured to estimate a torque output of the engine based on the normalized spark timing and the at least one normalized other parameter using a mathematical model.