A system and method for operating a vehicle equipped with an automatic stop and start system is disclosed. The vehicle includes an internal combustion engine, an automatic transmission and a fluid launch device with an impeller disconnect clutch. A controller may initiate an automatic stop or start of the engine under certain operating conditions. During an engine start/stop event, the engine is automatically shut down and the impeller clutch of the fluid launch device may be disengaged to decouple the engine and transmission from the driveline to provide for improved fuel economy and reduced emissions.

This vehicle transmission system includes a transmission (21) in which a gear is shifted by an operation of a driver of a vehicle (1), a clutch device (26) that is disposed in a motion transfer path between the transmission (21) and an engine (13) of the vehicle (1), and is disconnected and connected by an action of a clutch actuator (50), and a clutch control unit (61) that is configured to control disconnection and connection of the clutch device (26) by the clutch actuator (50). In a case where the vehicle (1) is started with a gear position of the transmission (21) located at or above a gear that is set in advance, and a vehicle speed (V) is less than or no higher than a set value (v2) that is set in advance, the clutch control unit (61) transitions to clutch capacity-limiting control in which a clutch capacity is reduced below that during normal clutch control.

A controller executes a method to manage an engine connect/disconnect decision in a powertrain having an engine, transmission, electric machine, and a battery pack and power inverter module (“TPIM”). In response to vehicle ground speed being less than a calibrated maximum electric vehicle accelerator pedal signal (“EV.sub.APS”) level, the controller calculates a delta APS (“ΔAPS”) value by subtracting a scaled APS value from the actual APS level. The scaled APS value is a scaled variant of a maximum EV.sub.APS value selected from a maximum EVS.sub.APS table, the latter populated based on inverter temperature, state of charge of the battery pack, and ground speed. When the ΔAPS value exceeds a threshold, the controller connects the engine to the transmission via an engine disconnect clutch. The engine is disconnected based on acceleration of the vehicle and the above-noted factors.

Operating a drive train of a vehicle having a clutch assembly, wherein the clutch assembly is actuatable via an actuating device for the switchable transmission of a torque, wherein a first state of the actuating device, and thus a second state of the clutch assembly, is settable via a position of a drive unit of the actuating device, comprises: a) determining that a first torque request to the clutch assembly is constant; and b) determining that a first position of the drive unit is constant within the interval; and then c) controlling the drive unit with a dither function, wherein a position of the drive unit is continuously varied about the first position; and d) ending the dither function when the conditions stated in steps a) and b) are no longer met.

This vehicle transmission system includes a transmission (21), a clutch device (26), a clutch control unit (61), and a shift operation detecting means (48), and, when a hydraulic pressure is supplied from a clutch actuator (50) to a slave cylinder (28), the clutch device (26) moves to a connection side, in an in-gear stop state in which the transmission (21) is in an in-gear state, and a vehicle (1) is in a stop state, the clutch actuator (50) supplies a standby hydraulic pressure (WP) to the slave cylinder (28), and the clutch control unit (61) sets the standby hydraulic pressure (WP) to a first setting value (P1) during non-detection in which a shift operation is not detected by the shift operation detecting means (48) and sets the standby hydraulic pressure (WP) to a second setting value (P2) lower than the first setting value (P1) when the shift operation is detected by the shift operation detecting means (48).

A start control device is a start control device that controls start of a vehicle including a clutch that is engaged by the hydraulic pressure supplied from a hydraulic pressure supply source and a start device that starts a vehicle driving source, and includes: a hydraulic pressure control unit that controls so that the hydraulic pressure supply source supplies the hydraulic pressure to the clutch if a start condition for the vehicle is satisfied; and a start device control unit that controls the start device so that the rotation speed of the vehicle driving source reaches the predetermined rotation speed after the clutch is engaged.

This vehicle transmission system includes a transmission (21), a clutch device (26), a clutch control unit (61), and a shift operation detecting means (48), and, when a hydraulic pressure is supplied from a clutch actuator (50) to a slave cylinder (28), the clutch device (26) moves to a connection side, in an in-gear stop state in which the transmission (21) is in an in-gear state, and a vehicle (1) is in a stop state, the clutch actuator (50) supplies a standby hydraulic pressure (WP) to the slave cylinder (28), and the clutch control unit (61) sets the standby hydraulic pressure (WP) to a first setting value (P1) during non-detection in which a shift operation is not detected by the shift operation detecting means (48) and sets the standby hydraulic pressure (WP) to a second setting value (P2) lower than the first setting value (P1) when the shift operation is detected by the shift operation detecting means (48).

A controller executes a method to manage an engine connect/disconnect decision in a powertrain having an engine, transmission, electric machine, and a battery pack and power inverter module (TPIM). In response to vehicle ground speed being less than a calibrated maximum electric vehicle accelerator pedal signal (EV.sub.APS) level, the controller calculates a delta APS (PS) value by subtracting a scaled APS value from the actual APS level. The scaled APS value is a scaled variant of a maximum EV.sub.APS value selected from a maximum EVS.sub.APS table, the latter populated based on inverter temperature, state of charge of the battery pack, and ground speed. When the APS value exceeds a threshold, the controller connects the engine to the transmission via an engine disconnect clutch. The engine is disconnected based on acceleration of the vehicle and the above-noted factors.

The present disclosure relates to an Extended Idle Stop and Go (E-ISG) control device and method for a vehicle. The E-ISG control device includes a Brake Pedal Sensor (BPS) that outputs an ON signal when a user depresses a brake pedal and outputs an OFF signal when the user does not depress the brake pedal and a controller that stops operation of an engine and opens an electronic clutch when the vehicle is not in N gear during travel and the ON signal is output from the BPS.

A clutch control method is provided for a four-wheel-drive vehicle in which the main drive wheels are connected to a drive source, and the auxiliary drive wheels are connected via a friction clutch to the drive source. When the vehicle starts off due to an accelerator depressing operation, the friction clutch is engaged to distribute, a drive torque from the drive source to the main drive wheels and the auxiliary drive wheels. In this clutch control method, when the vehicle switches from a traveling state to a stopped state while maintaining in a travel shift position, a control is preformed to apply initial torque as an engagement torque control of the friction clutch while the vehicle is stopped. A magnitude of the initial torque is set to a magnitude that maintains a drive-system torsion state by transmitting torque to an auxiliary-drive-wheel drive system before the vehicle is stopped.