The present disclosure provides a method in a vehicle, comprising detecting an engine stop opportunity and recording, in a memory, data corresponding to a first engine stop that occurred in response to detection of the engine stop opportunity. The method further includes detecting an engine stop inhibit, and recording, in a memory, data corresponding to a first missed engine stop wherein the first missed engine stop indicates detection of the engine stop opportunity without an engine stop in response to the detection of the engine stop opportunity.

Methods and systems are provided for a starter motor system for cranking an engine. In one example, a starter motor system includes, a battery, two electric motors arranged in series, two main contactors, two auxiliary contactors, and two solenoid contactors. Each of the two electric starter motors may be simultaneously energized to crank the engine in tandem after the pinion gears of both the electric motors are coupled to the ring gear of the engine.

Methods and systems are provided for a starter motor system for cranking an engine. In one example, a starter motor system includes, a battery, two electric motors arranged in series, two main contactors, two auxiliary contactors, and two solenoid contactors. Each of the two electric starter motors may be simultaneously energized to crank the engine in tandem after the pinion gears of both the electric motors are coupled to the ring gear of the engine.

A control device is configured to read a required operation point of the internal combustion engine at the moment of restart following after intermittent stoppage, and to execute, when it is determined that the required operation point belongs to a reduced-cylinder operation allowed region and also to a reduced-cylinder operation restricted region which lies on a high load side of the reduced-cylinder operation allowed region, an all-cylinder operation and then move into a reduced-cylinder operation. When it is determined that the required operation point belongs to the reduced-cylinder operation allowed region but not to the reduced-cylinder operation restricted region, the control device is configured to switch the engine to the reduced-cylinder operation without execution of the all-cylinder operation.

Provided is an electric power system mounted on a vehicle having an engine, a battery, and a starter that starts the engine. The electric power system includes an SOC estimation part, estimating the SOC of the battery based on a first algorithm; an idling stop control part, permitting implementation of an idling stop control when an estimation result of the SOC estimation part satisfies a predetermined automatic stop condition; a full charge determination part, determining whether the battery is in a full charge state based on a second algorithm different from the first algorithm; and a malfunction determination part, determining that malfunction occurs in the SOC estimation part when the battery is estimated in the full charge state by the full charge determination part and the estimation result of the SOC estimation part does not satisfy the automatic stop condition.

Provided is an electric power system mounted on a vehicle having an engine, a battery, and a starter that starts the engine. The electric power system includes an SOC estimation part, estimating the SOC of the battery based on a first algorithm; an idling stop control part, permitting implementation of an idling stop control when an estimation result of the SOC estimation part satisfies a predetermined automatic stop condition; a full charge determination part, determining whether the battery is in a full charge state based on a second algorithm different from the first algorithm; and a malfunction determination part, determining that malfunction occurs in the SOC estimation part when the battery is estimated in the full charge state by the full charge determination part and the estimation result of the SOC estimation part does not satisfy the automatic stop condition.

The present disclosure provides a method in a vehicle, comprising detecting an engine stop opportunity and recording, in a memory, data corresponding to a first engine stop that occurred in response to detection of the engine stop opportunity. The method further includes detecting an engine stop inhibit, and recording, in a memory, data corresponding to a first missed engine stop wherein the first missed engine stop indicates detection of the engine stop opportunity without an engine stop in response to the detection of the engine stop opportunity.

The invention relates to a method for rotational positioning of a heat engine rotor (3) that is in a stopped position (.sub.A) to a target position (.sub.0), comprising the following steps: a device for detecting the angular position of the rotor (3) determines an angular difference () from the target position (.sub.0), a speed set-point (.sub.c()) as a function of the angular position () of the rotor (3) is established from the angular difference (), with a rising slope less than a predetermined value (a) followed until a high speed value is reached less than a predetermined value (.sub.0), and a falling slope less than a predetermined value (b), the rotor (3) is set in motion following the speed set-point (.sub.c()).

According to some aspects, methods and systems are presented to reduce noise, vibration, and harshness during start or restart of an engine. In some embodiments, a torque source such as an electric machine provides a torque to an internal combustion engine during restart to counteract vibrations of the system caused by the output torque of the internal combustion engine. The torque provided by the torque source can be expressed as a sum of a non-linear component and an input shaped component. A perturbation technique can be utilized for separating the scales and isolating the non-linear response of the system. Command shaping can be applied to the remaining, linear response of the system. Parameters used in the modeling of the internal combustion engine and the system may be pre-determined based on vehicle design and operating conditions, or may be iteratively estimated based on previous restarts during vehicle operation.

A method for fault-tolerant coasting control of a powertrain system having an engine and a first energy storage system (ESS) includes receiving a real impedance value of the first ESS from a frequency analyzer device at a calibrated frequency while the engine is running, and comparing the real impedance value to a calibrated impedance. A coasting maneuver is enabled allowing the engine to turn off above a threshold speed when the real impedance value is less than the calibrated impedance. The method may include starting the engine using a second ESS in parallel with the first ESS to exit the coasting maneuver when the real impedance value exceeds the calibrated impedance. Subsequent execution of the coasting maneuver may be prevented as long as the real impedance value exceeds the calibrated impedance. A powertrain system includes the engine, starter motor, rechargeable ESS, frequency analyzer, and controller.