A system and method for operating a hybrid vehicle having an engine and an eMachine coupled by a clutch using a hybrid controller is presented. The method determines an idle fuel rate of the engine, determines a hybrid efficiency index for the hybrid vehicle, determines an expected energy storage rate increase for an operating condition where the engine is decoupled from a vehicle transmission using said clutch, multiplies the expected energy storage rate increase by the hybrid efficiency index to determine an expected fuel rate reduction of the engine in the operating condition; and decouples the engine from the vehicle transmission using the clutch if the expected fuel rate reduction is greater than the idle fuel rate.

A vehicle including a continuously variable transmission including a gear selectively locked to an output shaft via a clutch actuated by an electric coil. The vehicle also includes a controller configured to, in response to wheel hop being detected, energize the coil to disengage the clutch allowing the gear and the output shaft to rotate independently of each other.

A vehicle includes an engine, an automatic transmission, a second clutch for engine disconnection, a rotating electric machine, a first clutch for rotating electric machine separation, and an electronic control unit. The electronic control unit switches the first clutch from a release state to an engagement state in a case where a collision of the vehicle occurs, the first clutch is in the release state, and a rotation speed of the rotating electric machine is higher than an input shaft rotation speed of the automatic transmission. In a case where the collision of the vehicle occurs, the first clutch is in the release state, and the rotation speed of the rotating electric machine is lower than the input shaft rotation speed of the automatic transmission, the first clutch is maintained in the release state.

A method of controlling a hybrid vehicle is provided, which includes shifting a friction engagement element from a released state to a slipping or engaged state, and performing motor control where an engine is started using a motor in response to a startup demand of the stopped engine during vehicle traveling, applying as the motor control a first control in which a target speed to be set for the motor is instructed and feedback control of the motor is executed based on a speed detected by a motor speed sensor to be the target speed, determining whether a condition for switching the motor control from the first control to a second control in which a target torque to be outputted from the motor is instructed to cause the motor to output the target torque, is satisfied, and when determined to be satisfied, switching the motor control to the second control.

A control strategy is provided for a hybrid vehicle that will increase drivability during low or decreasing driver demands. Coordination between shifting the transmission and stopping or (non-demand) starting of the engine can increase drivability. The vehicle includes a motor/generator with one side selectively coupled to the engine and another side selectively coupled to the transmission. The control strategy acts when an engine start or stop is requested while driver demand is decreasing and a shift of the transmission is demanded. To inhibit these events from proceeding simultaneously, the control strategy delays the engine from starting or stopping until the transmission has finished shifting, or vice versa.

An oxygen sensor diagnosis control system of a hybrid electric vehicle is provided. The system of a hybrid electric vehicle eliminates an uncertainty of the number of diagnoses of an oxygen sensor and restrains diagnoses of the oxygen sensor in a hybrid electric vehicle. The system of a hybrid electric vehicle includes a hybrid controller operates a vehicle, and determines conversion of an oxygen sensor diagnosis mode based on a result obtained by calculating an oxygen sensor diagnosis index. Additionally, the controller determines whether a condition for diagnosing an oxygen sensor is satisfied when the oxygen sensor diagnosis index decreases to initiate a diagnosis inducing mode or a compulsory diagnosis mode.

A vehicle control apparatus includes a planetary gear mechanism, first and second wheels, an engine, a motor generator, a wheel drive clutch, and a control system. The planetary gear mechanism includes first, second, and third rotation elements. The first wheel is coupled to the first rotation element via a first path. The second wheel is coupled to the second rotation element via a second path. The engine is coupled to the third rotation element via a third path. The motor generator is provided on the first path. The wheel drive clutch is provided on the first path and between the motor generator and the first wheel. The control system controls the motor generator and the wheel drive clutch. The control system executes a motor stop mode in which the wheel drive clutch is brought into a released state and the motor generator is brought into a rotation stop state.

Systems and methods for operating a hybrid powertrain that includes an engine and a motor/generator are described. The systems and methods align in time an estimated motor torque and an actual motor torque to provide an estimated driveline torque. The alignment compensates for communications delays between different controllers over a controller area network.

A vehicle includes a transmission, an engine, a clutch, and a controller. The transmission has an input. The engine is configured to generate and deliver torque to the input. The clutch is configured to connect and disconnect the engine from the input, and to crank the engine during an engine start. The controller is programmed to, in response to a command to adjust a torque of the clutch during an engine start and a presence of first condition of the clutch, drive a clutch actuator pressure to a first desired value based on a first transfer function. The controller is further programmed to, in response to a command to adjust the torque of the clutch during the engine start and a presence of a second condition of the clutch, drive the clutch actuator pressure to a second desired value based on a second transfer function.

A hybrid vehicle includes an electric machine, an engine selectively coupled to the electric machine by a disconnect clutch, and a controller. The controller is programmed to, in response to a change in the driver-demanded torque necessitating starting of the engine: determine a state of driving (SOD) based on the change in driver-demanded torque, wherein the SOD is indicative of a desired responsiveness of the vehicle, and the desired responsiveness increases as SOD increases; command a speed target to the engine equal to a predicted motor speed associated with the driver-demanded torque plus an offset that is based on the SOD; and command a capacity to the disconnect clutch at a rate and a magnitude based on the SOD.