A controller controls an electric motor such that a pulsation compensation torque corresponding to a pulsation component of a torque of an internal combustion engine, which appears in a drive shaft, is supplied to the drive shaft as a damping torque for suppressing vibrations of a hybrid vehicle. A determination is made as to whether a torque of the electric motor, excluding the pulsation compensation torque, is smaller than a predetermined value. When it is determined that the torque excluding the pulsation compensation torque is smaller than the predetermined value, the controller selects one mode having a highest energy efficiency of the hybrid vehicle from among a plurality of modes, and controls the internal combustion engine and the electric motor based on the selected mode.

The invention relates to a method for vibration dampening of a drive train, including an internal combustion engine which has an engine torque (Mvm) from a crankshaft, an electric machine, a transmission which has a transmission input shaft and a torque transmission device arranged between the crankshaft and the transmission input shaft, which torque transmission device has at least one flywheel mass capable of oscillating with a moment of inertia (J 1, J2, J3) and a state controller for controlling the electric machine by a compensation torque (Mregler) compensating for torsional vibrations on the transmission input shaft. In order to achieve high-quality vibration damping, input variables of the state controller are determined by at least one observer for reconstructed rotational characteristic values of the at least one flywheel mass from detected rotational speeds or angles of rotation of the drive train, and the reconstructed rotational characteristic values are determined according to the disturbance variables in the form of a load torque (Mlast) from an output of the torque transmission device and of an induced torque (Mind) transmitted via the torque transmission device from the motor torque of the internal combustion engine.

Provided are a driving force control method and device for a hybrid vehicle, each capable of effectively absorbing torque fluctuation of an engine while suppressing deterioration in energy efficiency. The driving force control device for a hybrid vehicle comprises a PCM configured to: identify a vehicle acceleration; estimate an average torque output by an engine; estimate a torque fluctuation component of the torque output by the engine; set a countertorque for suppressing the estimated torque fluctuation component; and control an electric motor to output the set countertorque, wherein the PCM is operable, under a condition that an engine speed and the average torque output by the engine are constant, to set the countertorque such that, as the absolute value of the vehicle acceleration becomes smaller, the absolute value of the countertorque becomes larger.

A method to control a road vehicle during a slip of the drive wheels, which are caused to rotate by an internal combustion engine provided with a plurality of cylinders arranged in two banks, and with a plurality of fuel injectors each injecting fuel into a corresponding cylinder. The control method comprises the steps of: detecting a slip of at least one drive wheel; and controlling the internal combustion engine, only during a slip of at least one drive wheel, with a signalling law, which causes the internal combustion engine to work in an abnormal manner so as to generate an abnormal vibration and/or an abnormal noise, which can be perceived by the driver. The internal combustion engine has two twin control units, each of which is associated with a corresponding bank, controls all and the sole injectors of its own bank and actuates the signalling law completely independently of and autonomously from the other control unit.

A system and a method for reducing a rotational imbalance of a drive train of a hybrid vehicle are provided. The drive train includes an internal-combustion engine, an electric machine, and a crankshaft. A reduction or nullification of the rotational imbalance takes place by actuating the electric machine. The actuation is implemented as an adaptive feed forward control, which provides an actuation signal for the electric machine. The actuation signal represents a desired torque to be generated by the electric machine, so that the electric machine outputs a torque that is at least approximately inverse with respect to the rotational imbalance to the crankshaft for the superimposition of the torque generated by the internal-combustion engine.

A motor control device according to an embodiment includes a hardware processor configured to: calculate a first torsion torque generated by a motor shaft according to fluctuation of an engine torque based on a difference between a motor angle as a rotation angle of the motor shaft and a shaft angle as a rotation angle of a transmission shaft of a transmission on the downstream side of a damper; calculate a first vibration damping torque to be output by a motor generator to damp vibration of the motor shaft based on the first torsion torque and a drive state value indicating a drive state of an engine; and output a motor torque command value to be provided to the motor generator based on the first vibration damping torque.

Methods and systems are provided for controlling engine operation in a hybrid vehicle, where the vehicle engine comprises one or more cylinders dedicated to recirculating exhaust to the intake manifold. In one example, if an engine load decreases below a level where dedicated exhaust gas recirculation may lead to combustion stability issues, engine load may be increased above the demanded load and the excess power used to charge a system battery, or if the battery state of charge is above a threshold, the engine may be shut down and the vehicle propelled via battery power. In this way, fuel economy and combustion stability issues may be improved, NOx emissions reduced, and costs for implementation of dedicated exhaust gas recirculation decreased.

Methods and systems are provided for controlling hybrid vehicle engine operation, where the vehicle engine comprises one or more cylinders dedicated to recirculating exhaust to an intake manifold. In one example, during an engine cold-start event or other event where temperature of one or more exhaust catalysts are below a temperature needed for catalytic activity, fuel injection to the dedicated exhaust gas recirculation cylinder(s) is maintained shut off, while its intake and exhaust valves are maintained activated, thus enabling the dedicated exhaust gas recirculation cylinder(s) to route air to the intake manifold of the engine, resulting in exhaust gas lean of stoichiometry that may serve to heat the catalyst. In this way, during cold start events and other events where temperature of one or more exhaust catalysts are below a temperature for catalytic activity, combustion stability issues may be avoided, and exhaust catalyst(s) rapidly heated, thereby reducing undesired tailpipe emissions.

A transmission system for a hybrid electric vehicle includes a planetary gear mechanism, a gear, a parking lock mechanism, and a resistance imposing device. A parking meshing member of the parking lock mechanism acts so as to switch between a first state where a claw is in mesh with a parking gear and a second state where the claw is out of mesh with the parking gear. The resistance imposing device includes a resistance imposing member configured to impose a rotational resistance on the parking gear or a third rotating element of the planetary gear by coming in contact with the parking gear or the third rotating element. The resistance imposing device is configured to operate the resistance imposing member such that a larger rotational resistance is imposed on the third rotating element in the first state than in the second state.

The invention relates to a device and to a method for controlling a test stand arrangement having a specimen and having a loading machine, which is connected to the specimen by a connecting shaft. An estimated value (T.sub.E,est) for for the internal torque (T.sub.E) of the specimen is determined and, from the estimated value (T.sub.E,est), while taking into account a natural frequency (f.sub.0) and a delay, a damping signal (T.sub.Damp) is determined and fed back into the control loop.