An electric vehicle includes a drive motor configured for generating power required for driving of the vehicle, a twin clutch which may include a first clutch and a second clutch and configured to adjust distribution of the power supplied from the drive motor to a first drive wheel and a second drive wheel of the vehicle through the first clutch corresponding to the first drive wheel and the second clutch corresponding to the second drive wheel, and a controller electrically connected to the twin clutch and configured to, when a control condition for a deceleration turning of the vehicle is satisfied, determine a control torque of the twin clutch as a larger value of an initial torque to prevent slip of the twin clutch and a base torque determined based on output torque of the drive motor, and distribute the control torque to the first clutch and the second clutch depending on a drive mode of the vehicle.

A powertrain for a vehicle is disclosed that includes an electromagnetic driving unit (10) and a transmission module (20) comprising a controllable clutch (21) the powertrain further includes a control system to control the electromagnetic driving unit and to control the clutch. The controller has a safety operational mode wherein it controls an engagement of the controllable clutch with a feedback loop in which a desired extent of engagement is positively correlated to a difference between an extent of slip as indicated by the slip indicator and a positive reference value for said extent of slip, wherein the slip indicator indicates the extent of slip with a sign that is the product of the sign of the difference between the rotational speed of the input shaft and a rotational speed of the output shaft and a desired driving torque sign.

A friction engagement element control system is provided, which includes a friction engagement element including friction plates, and an actuation system configured to engage an input-side friction plate with an output-side friction plate with a pushing force, the friction plates having a negative slope characteristic in which a friction coefficient thereof decreases as a rotational difference between the friction plates increases, a rotational difference sensor of the friction engagement element, a separator configured to divide a variation in the detected rotational difference into a high-frequency component that is a vibration component and other low-frequency components, and a controller configured to control a pushing force only for the vibration component of the rotational difference so that the negative slope characteristic becomes a positive slope characteristic in which a frictional force of the friction engagement element decreases as the rotational difference decreases, when engaging the friction engagement element.

In a hybrid vehicle, a hybrid type lubrication control valve which is a solenoid valve type turned on/off by electricity is used as a lubrication system component for circulating lubricating oil to a transmission and an engine clutch. A method includes measuring, by an engine clutch pressure sensor, first engine clutch engagement pressure in an off-state of the independent type lubrication control valve and second engine clutch engagement pressure in an on-state thereof; and determining, by the TCU, whether or not the independent type lubrication control valve is stuck, on the basis of a pressure difference between the first engine clutch engagement pressure and the second engine clutch engagement pressure. The method can diagnose a stuck state of the hybrid type lubrication control valve using hydraulic pressure for operating engine clutch engagement, before starting the vehicle.

A mean rate decision method for a clutch motor is disclosed. The method includes determining whether the clutch motor and a gear sensor are in an electrical failure state; when it is determined the clutch motor and the gear sensor are not in the electrical failure state, determining whether there is a driver's starting intention on the basis of state information on the clutch pedal; setting a target position of the clutch motor according to a pedal setting value set by the clutch pedal; and when it is determined that there is no driver's starting intention and that an actual position of the clutch motor exceeds the target position of the clutch motor, determining a failure of the clutch motor on the basis of an excess movement amount and an excess duration in the excess state.

A shift control method can be used for a vehicle with a dual-clutch transmission (DCT). A controller determines whether or not a power-on upshift is initiated in a state in which a high performance mode has been selected. The controller performs a torque phase in which a coupling-side clutch torque is gradually increased and a release-side clutch torque is gradually released. The coupling-side clutch torque is gradually increased to a target coupling-side clutch torque corresponding to a value obtained by adding a push feel torque to a base torque. The controller performs an inertia phase in which the coupling-side clutch torque is gradually increased while tracing an engine torque such that an engine speed is synchronized with a coupling-side clutch speed. The controller completes speed change through gradual decrease of the coupling-side clutch torque.

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).

Methods of controlling a tandem axle assembly in a vehicle, the tandem axle assembly including an inter-axle differential (IAD), one or more side gears, and a front tandem axle assembly having a pair of front tandem axle half shafts selectively connected to a pair of front tandem axle wheel hub assemblies. When a determined speed of the vehicle is greater or equal to a predetermined speed, the IAD may be locked, the tandem axle wheel hub assemblies may be disconnected from their respective tandem axle shafts, and/or the IAD may be moved out of engagement with the one or more side gears. When a determined speed of the vehicle is less than a predetermined speed, the IAD may be unlocked, the tandem axle wheel hub assemblies may be connected to their respective tandem axle shafts, and/or the IAD may be engaged with the one or more side gears.

Disclosed is a method for controlling engagement of an engine clutch in a hybrid electric vehicle in which an engagement control method of the engine clutch is accurately determined so as to minimize a determination error and a sense of discontinuity caused by conversion of the engagement control method resulting therefrom.

A control device is to be applied to a four-wheel drive vehicle including a first coupling device interposed between a rear-wheel final gear device and a rear left wheel axle and a second coupling device interposed between the rear-wheel final gear device and a rear right wheel axle. The control device includes a controller changes a coupling torque of the first coupling device and a coupling torque of the second coupling device independently of each other. The controller estimates, when the vehicle is accelerating, a vehicle body speed of the vehicle under a state in which the coupling torque of any one of the first coupling device and the second coupling device is set to a value larger than zero and the coupling torque of another one thereof is set to zero. Thereby, the control device can accurately estimate the vehicle body speed when the vehicle is traveling while accelerating.