A method of controlling stability of a motorized vehicle having an electric motor as a drive source includes determining a slope of a road ahead, when sensing a sudden slope change point as a result of determination, determining a correction section based on the sudden slope change point, and correcting stability control torque in the correction section to compensate for motion of the vehicle body due to a change in the slope of the road using a pitching motion of the vehicle body caused by the torque of the electric motor.

A hybrid vehicle includes two drive sources and two clutches, and is switchable between a neutral mode and a parallel mode during vehicle traveling. The two drive sources are both disconnected from drive wheels in the neutral mode, and are both connected to the drive wheels in the parallel mode. A control method for the hybrid vehicle includes implementing at least one of a first switching control and a second switching control. The first switching control includes, upon switching from the neutral mode to the parallel mode, implementing two synchronization controls on rotational speeds before and after the two clutches, concurrently during at least a partial period. The second switching control includes, upon switching from the parallel mode to the neutral mode, implementing two controls to cause transmitted torques of the two clutches to respectively approach zero, concurrently during at least a partial period.

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.

When an alternator load torque Talt is larger than a threshold , a lockup clutch is released. Thus, a deceleration G can be restrained from becoming too large due to the alternator load torque Talt. Besides, the threshold is changed in accordance with a speed ratio of a continuously variable transmission. Thus, the deceleration G can be favorably controlled within a predetermined range. For example, in a vehicle state where a deceleration is unlikely to be achieved due to the smallness of the speed ratio , the threshold is large. Therefore, the lockup clutch is unlikely to be released, and the deceleration G is likely to be secured.

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.

A running control device of a vehicle includes an engine, a clutch separating the engine and wheels, and a torque converter with a lockup clutch transmitting power of the engine toward the wheels, the running control device of a vehicle is configured to execute a neutral inertia running mode that is an inertia running mode performed while the engine and the wheels are separated and a cylinder resting inertia running mode performed by stopping operation in at least some of cylinders of the engine while the engine and the wheels are coupled, the lockup clutch has a weak engagement force while the neutral inertia running mode is performed as compared to while the cylinder resting inertia running mode is performed.

A first control unit executes a valve stop inertial running including stopping an intake valve and an exhaust valve in a closed state during rotation of an output shaft, stopping supply of fuel to an engine, and setting a clutch in an engaged state to drive pistons of the engine by a rotational force from driving wheels. A second control unit executes a valve operation running including operating the intake valve and the exhaust valve during the rotation of the output shaft, and supplying the fuel to the engine based upon an intake conduit pressure. When a cancellation request is made during execution of the valve stop inertial running, a transient control unit operates the intake valve and the exhaust valve, and controls a throttle valve to an idling opening or less, thereby supplying a negative pressure to an intake passage.