Provided is a marine engine, including: a piston; and a compression ratio controller configured to execute lowering processing of moving a top dead center position of the piston toward a bottom dead center side when an engine rotation speed falls within a resonance occurrence range set in advance. A geometrical compression ratio is reduced, and a resonance stress caused by a torsional vibration in a rotary system can thus be suppressed while suppressing a decrease in thermal efficiency compared with a case in which retarding control is applied to a fuel injection timing or a closing timing of an exhaust valve.

In some embodiments of the present disclosure, an electric motor is used to generate correction torques to counteract unwanted torque pulses generated by an internal combustion engine during startup and/or shutdown. In some embodiments, the electric motor may be mounted to an accessory drive such as a power take-off mechanism or a front end accessory drive (FEAD). In some embodiments, the correction torques may be used to enforce an engine speed target profile for startup or shutdown, and may be determined using a feedback control loop based on the engine speed. The correction torques help to reduce or eliminate noise, vibration, and/or harshness (NVH) during startup and/or shutdown.

A vehicle controller includes a controlling section configured to control a torque applying mechanism. The controlling section is configured to execute a negative torque control by using the torque applying mechanism when execution conditions are satisfied. The execution conditions include a condition that an increase amount per predetermined time of the boost pressure has become greater than a preset boost pressure determination value. The negative torque control is a control to set the rotational torque applied to the crankshaft by the torque applying mechanism to a negative value that is on the negative side of a value immediately before the start of the negative torque control.

A variable gauge train control device comprises an inverter, a location detector, and a torque calculator. The inverter collectively controls torques of main electric motors. The location detector detects an entry into a gauge changeover section. The torque calculator, upon detection by the location detector of the entry into the gauge changeover section, suspends idling control that otherwise restricts the torques of the main electric motors and calculates a first torque pattern for making the inverter operate in accordance with the torques of the main electric motors.

A method for jumping cylinder deactivation (CDA) modes to avoid a primary powertrain resonant frequency in a six-cylinder diesel engine-powered machine comprises operating an engine between an idled condition and a first engine speed limit in one of a two-cylinder CDA mode or a four-cylinder CDA mode. The method operates the engine between the first engine speed limit and a second engine speed limit in a three-cylinder CDA mode. The first engine speed limit is an engine speed below which the two-cylinder or four-cylinder CDA mode causes the machine to operate below a primary powertrain resonant frequency and also above which the three-cylinder CDA mode causes the machine to operate above the primary powertrain resonant frequency, thus avoiding the primary powertrain resonant frequency during operation. A CDA mode can be selected above the second engine speed limit to operate the machine above the primary powertrain resonant frequency.

Disclosed are a method of and an apparatus for controlling a vibration of a hybrid electric vehicle. An apparatus for controlling a vibration of a hybrid electric vehicle may include: an engine position detector detecting a position of an engine; an air amount detector detecting an air amount flowing into the engine; an accelerator pedal position detector detecting a position of an accelerator pedal; a vehicle speed detector detecting a speed of the hybrid electric vehicle; and a controller. The controller controls operation of a motor based on the position of the engine, the air amount, the position of the accelerator pedal, and the speed of the hybrid electric vehicle.

A method of controlling an internal combustion engine having a plurality of cylinders, in particular a stationary internal combustion engine, wherein actuators of the internal combustion engine are actuable in crank angle-dependent relationship and/or sensor signals of the internal combustion engine can be ascertained in crank angle-dependent relationship, for compensation of a torsion of a crankshaft, by which torsion deviations in the crank angle occur between a twisted and an untwisted condition of the crankshaft, wherein for at least two of the cylinders a cylinder-individual value of the angle deviation is ascertained and the crank angle-dependent actuator or sensor signals are corrected in dependence on the detected angle deviation.

A vehicle controller includes a controlling section configured to control a torque applying mechanism. The controlling section is configured to execute a negative torque control by using the torque applying mechanism when execution conditions are satisfied. The execution conditions include a condition that an increase amount per predetermined time of the boost pressure has become greater than a preset boost pressure determination value. The negative torque control is a control to set the rotational torque applied to the crankshaft by the torque applying mechanism to a negative value that is on the negative side of a value immediately before the start of the negative torque control.

A method for protecting a dual mass flywheel DMF, by detecting, when the engine in running, that the DMF is entering into resonance, the DMF being arranged between an internal combustion engine and a gearbox of a vehicle, comprising the following steps: Determining the average rotational speed (Vvil.sub.moy) of the crankshaft, over time, over a predetermined given period, as a first parameter constituting a risk of the DMF entering into resonance, Measuring the maximum instantaneous rotational speed and the minimum instantaneous rotational speed of the crankshaft, the difference defining the maximum amplitude (Amp.sub.Vvil) of the rotational oscillations of the crankshaft, over the period, as a second parameter constituting a risk of the DMF entering into resonance, Detecting when the DMF is entering into resonance from a determined combination of values of the first and second parameters, over the period, limiting or cutting off the fuel injection in the cylinders after said detection.

A method for entering and exiting cylinder deactivation modes in a diesel engine, comprises monitoring an engine speed from an idle engine speed to a governed engine speed and monitoring an engine load. If the monitored engine speed is the idle engine speed up to the governed engine speed, and if the engine load is less than the predetermined low load condition, then implementation of a cylinder deactivation mode is restricted to one of a 2 cylinder deactivation mode, a 3 cylinder deactivation mode, or a 4 cylinder deactivation mode. A cylinder deactivation mode is selected for engine operation among the 2 cylinder deactivation mode, the 3 cylinder deactivation mode, and the 4 cylinder deactivation mode to operate the engine at an effective frequency that avoids two resonant frequencies of the vehicle and to operate the engine below a torsional vibration limit.