A variety of methods and arrangements for mitigating powertrain and accessory torsional oscillation through electric motor/generator control are described. In one aspect, working chamber air charge and crank position are determined prior to starting an engine. During the engine startup period, an electric motor/generator supplies a smoothing torque to at least partially cancel engine torque variations.

A starter assembly includes a housing defining an interior, a rotatable pinion gear wherein the rotatable pinion gear extends exteriorly of the housing and operably coupling to a combustion engine, a torque sensor providing a torque output indicative of a torque experienced by the pinion gear, and a controller module configured operate a starting sequence for the starter assembly.

An internal-combustion engine includes a belt-driven starter generator and makes an idling stop while a vehicle is at a stop. In the process of the engine revolution speed decreasing with cutting of fuel to stop the vehicle, to suppress the reduction in restart responsiveness caused by slack in a belt, preliminary powering of the starter generator is performed. The belt tension during deceleration microscopically changes periodically between a relatively high-tension period and a relatively low-tension period due to pulsation of the engine revolution speed. Slack in the belt does not occur in the high tension period, and thus preliminary powering torque is applied only in the low-tension period.

A method and a system for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft are disclosed. An absolute angular position of the crankshaft related to a top dead center position of a piston in a combustion chamber of the ICE is determined. Electric power is delivered to the ETM at a first level to rotate the crankshaft. Electric power is then delivered to the ETM at a second level greater than the first level when the piston reaches a predetermined position before the TDC position. Fuel is injected in the combustion chamber after the piston has passed beyond the TDC position. The fuel is then ignited. In an implementation, the ICE is started in less than 110 degrees of rotation of the crankshaft.

An air turbine starter (ATS) assembly includes a rotatable pinion gear (72) wherein the rotatable pinion gear is coupled to a combustion engine (10), a speed sensor (78) measuring the rotational speed (302) of the rotatable pinion gear (72), a torque sensor (79) providing a torque output (304) indicative of a torque experienced by the pinion gear (72), and a controller module configured to operate a starting sequence for the ATS assembly such that the rotational speed (302) is controllably increased while the torque output (304) is kept below the start sequence torque threshold (310).

Disclosed is a method for managing the starting of a combustion engine of a hybrid drive system including a combustion engine and an electric machine, as well as a drive shaft, the electric machine producing torque to start the combustion engine and drive the drive shaft at least during an initial phase of the start. In a transient starting phase, the combustion engine drives the drive shaft and the electric machine is stopped. The electric machine is regulated, during the initial phase and transient phases, with a first engine speed setpoint. The transient phase begins when the drive shaft reaches the first engine speed setpoint and remains steady. Torque control produced by the electric machine during the transient starting phase being configured so that the electric machine is stopped as soon as the control determines that the torque produced by the electric machine is tending toward zero torque.

A method for starting an internal combustion engine (ICE) having a crankshaft and an electric turning machine (ETM) operatively connected to the crankshaft comprises energizing an absolute position sensor adapted for providing an indication of an angular position of a rotor of the ETM and applying a current to the ETM to generate a sufficient torque to rotate the crankshaft.

When an engine during rotation stop is started, a target cranking speed is set to a value at which a first rotating machine MG1 is maintained in an electric power generation state when a request engine power is an output that needs a turbocharging pressure and which is higher than when the request output is not the output that needs the turbocharging pressure, and even after the engine is brought into the operating state, an MG1 cranking torque is controlled to apply a torque for increasing an engine speed of the engine to the target cranking speed to the engine. In this way, it is possible to increase the engine speed after an autonomous operation more quickly while suppressing power consumption of the first rotating machine MG1.

A first controller includes a start control section and a passage determination section. After activating a second starter to start cranking, the start control section stops the operation of the second starter and starts the motor operation of the first starter at a predetermined timing. The passage determination section determines whether a predetermined passage conditional expression holds after cranking is started by the second starter. The start control section stops the operation of the second starter and starts the motor operation of the first starter if the passage conditional expression holds before the engine passes the first compression top dead center, regardless of whether the engine has passed the first compression top dead center.

A vehicle includes an engine and an electric machine coupled to a transmission element. The electric machine is also selectively coupled with the engine by a clutch. The vehicle includes a belt integrated starter-generator (BISG) operatively coupled to the engine. An electronic controller includes one or more inputs adapted to receive a temperature measurement and a request to start the engine. The electronic controller is programmed to energize the BISG and the electric machine in response to receiving an engine start request and a temperature measurement being less than a threshold temperature measurement. The electronic controller is further programmed to close the disconnect clutch to apply torque from the electric machine to the engine in response to the electric machine achieving a threshold electric machine speed.