A system and method for dynamically deactivating engine cylinders of an engine equipped with a cylinder deactivation system, where the system and method control torsional vibration in the engine while deactivating cylinders using a computer programed with a desired firing density and a controlled range of engine vibration frequencies. The computer dynamically determines a cylinder firing pattern that provides the desired firing density while optimizing a cost function norm in the controlled range of engine vibration frequencies. The cylinder deactivation system in the engine is then controlled using the determined cylinder firing pattern.

A control method for an internal combustion engine configured to implement fuel cut in response to becoming zero of an accelerator opening degree during travel of a vehicle, and generate an antiphase torque after the fuel cut by supplying fuel to a cylinder, in order to cancel out vibration of the vehicle caused due to the fuel cut includes setting a timing of generating the antiphase torque to be later than that for normal operation, in response to implementation of the fuel cut under high torque idle operation in which a torque of the internal combustion engine immediately before the fuel cut where the accelerator opening degree is zero is higher than that in the normal operation.

A piston engine is provided; the piston engine has a cylinder, a main piston and an auxiliary piston; a combustion chamber is formed between the main piston and the auxiliary piston within the cylinder; the main piston has an crankpin offset L0, the auxiliary piston and the main piston move in different frequencies, an extended constant V≈Vc of the combustion chamber is formed from θ to >10° CA; when at a=θ=arc sin[L0/(L+R)] the main piston is at its top dead center; at a=arc sin(L0/R) the side force on the main piston is 0; when peak pressure of combustion is located at PPmax by choosing ignition timing, the most effective torque can be obtained; the torque is controlled by the amount of fuel injected; engine knocking can be prevented by retarded ignition at a>θ.

The engine controller includes storage which stores a fuel efficiency operation line for optimizing engine fuel consumption and a booming noise avoidance operation line for keeping the booming noise below a certain limit. The operation point region where the booming noise exceeding the certain limit is generated is a booming noise region. The fuel efficiency operation line passes through the booming noise region. In contrast, the booming noise avoidance operation line does not pass through the booming noise region. The controller controls the engine according to the booming noise avoidance operation line. The controller controls the engine according to the fuel efficiency operation line for a predetermined period after determining that the driver intends to change the speed of the vehicle.

Methods, devices, estimators, controllers and algorithms are described for estimating the torque profile of an engine and/or for controlling torque applied to a powertrain by one or more devices other than the engine itself to manage the net torque applied by the engine and other device(s) in manners that reduce undesirable NVH. The described approaches are particularly well suitable for use in hybrid vehicles in which the engine is operated in a skip fire or other dynamic firing level modulation manner—however they may be used in a variety of other circumstances as well. In some embodiments, the hybrid vehicle includes a motor/generator that applies the smoothing torque.

A vehicle control system for a powertrain including an internal combustion engine having an intake valve and an exhaust valve in a vehicle includes an electronic control unit (ECU) operable to control a continuously variable valve duration (CVVD) of the intake and exhaust valves in the engine, a communicator operable to receive an input data from at least one input system, and a storage device having predetermined calibration value. The ECU of the vehicle control system is configured to reference the predetermined calibration values based on a received input data, determines to adjust the CVVD of the intake and exhaust valves, and send a signal to the engine for changing an overlap area of the CVVD. The vehicle control system operates a process for controlling the CVVD of the engine as a method.

A method for controlling an engine includes, with a fuel injector, injecting a quantity of fuel into a cylinder of the engine for combustion. The method further includes calculating a torsional power level for the cylinder in response to the combustion of the injected quantity of fuel, mapping the torsional power level to an injected fuel mass, and comparing the injected fuel mass to a reference fuel mass to determine a fuel mass offset. The engine may be controlled based on the determined fuel mass offset.

A control device for a hybrid vehicle is, in the process of stopping an internal combustion engine of the vehicle, capable of making twist angle fluctuation reduction control and crank angle position control mutually compatible. When a request for stopping the internal combustion engine has been issued, twist angle fluctuation reduction control is implemented without implementing crank angle position control, until, in the process of bringing the engine to a stopped state, the rotational speed of the internal combustion engine drops below the resonant rotational speed region of the torsional damper; and, after the rotational speed of the internal combustion engine has dropped below the resonant rotational speed region of the torsional damper in the process of bringing the engine to a stopped state, crank angle position control is implemented without implementing twist angle fluctuation reduction control, until stopping of the internal combustion engine has been completed.

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 second engine speed limit can be used to select a CDA mode that causes the machine to operate above the primary powertrain resonant frequency.

A balance assembly for an engine is provided. The balance assembly includes a first electric motor coupled to the engine and configured to rotate a first eccentric mass relative to the engine, the first eccentric mass being coupled to a first shaft of the first electric motor, and a second electric motor coupled to the engine and configured to rotate a second eccentric mass relative to the engine, the second eccentric mass being coupled to a second shaft of the second electric motor. The first and second electric motors are configured to rotate the first and second eccentric masses in order to balance a vibration characteristic of the engine.