Abstract: A vehicle includes an engine, an electric machine, a disconnect clutch, and a controller. The engine and the electric machine are each configured to generate power. The disconnect clutch is disposed between the engine and the electric machine. The controller is programmed to, in response to a command to start the engine, close the disconnect clutch to transfer power from the electric machine to the engine. The controller is further programmed to control the torque of the disconnect clutch via increasing a pressure applied to the disconnect clutch based on a first-order model of the pressure applied to the disconnect clutch. The controller is further programmed to adjust the model based on a difference between an expected pressure to the disconnect clutch and a measured pressure of the disconnect clutch during a time period prior to transferring torque through the disconnect clutch.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch is positioned according to whether or not there may be slip across the driveline disconnect clutch. In one example, slip may be inferred from vehicle speed and a torque converter impeller speed.

Abstract: A vehicle includes an engine, an electric machine, a disconnect clutch, and a controller. The engine and the electric machine are each configured to generate power. The disconnect clutch is disposed between the engine and the electric machine. The controller is programmed to, in response to a command to start the engine, close the disconnect clutch to transfer power from the electric machine to the engine. The controller is further programmed to control the torque of the disconnect clutch via increasing a pressure applied to the disconnect clutch based on a first-order model of the pressure applied to the disconnect clutch. The controller is further programmed to adjust the model based on a difference between an expected pressure to the disconnect clutch and a measured pressure of the disconnect clutch during a time period prior to transferring torque through the disconnect clutch.

Abstract: A method of producing a disconnect clutch includes producing a disconnect clutch, configured to selectively connect an engine and an electric machine, such that the disconnect clutch exhibits a clutch transfer function that causes a transmission output shaft torque variability that is less than a predetermined threshold during a simulated starting of the engine using the electric machine.

Abstract: A method is proposed to complete a power-on upshift while a vehicle encounters wheel slip conditions such as driving in loose sand. The wheels slip conditions may be detected based on a maximum rate of change of an output shaft exceeding a threshold. In response to the wheel slip conditions, one or more shift parameters may be adjusted to bias the shift toward a tie-up and decrease the chance of a flare. These modified shift parameters may include an increased stroke pressure, a delayed off-going clutch release timing, and an increased ratio change capacity.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch liftoff pressure is estimated according to a derivative of a driveline disconnect clutch pressure when a driveline disconnect clutch is being de-stroked. The driveline disconnect clutch may be prepositioned in anticipation of driveline disconnect closing based on the estimated driveline disconnect clutch liftoff pressure.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch is positioned according to whether or not there may be slip across the driveline disconnect clutch. In one example, slip may be inferred from vehicle speed and a torque converter impeller speed.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch is de-stroked in a particular way so that the driveline disconnect clutch may be de-stroked more consistently. The de-stroking process may be followed by boosting and stroking the driveline disconnect clutch so as to preposition the driveline disconnect clutch or holding the clutch at an offset below stroke pressure to minimize drag.

Abstract: A vehicle includes an engine, a transmission, and a controller. The engine is configured to generate power. The transmission is configured to transfer power from the engine to at least one drive wheel to propel the vehicle. The controller is programmed to, in response to a command to shift the transmission and a corresponding command to decrease a torque of the engine to less than a threshold corresponding to a spark retard limit during the shift, (i) increase the pressure of an oncoming clutch to engage the oncoming clutch, (ii) retard an engine spark at the spark retard limit to reduce the torque of the engine to the threshold during the engagement of the oncoming clutch, and (iii) shutdown at least one cylinder of the engine to further reduce the torque of the engine to less than the threshold during the engagement of the oncoming clutch.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch is de-stroked in a particular way so that the driveline disconnect clutch may be de-stroked more consistently. The de-stroking process may be followed by boosting and stroking the driveline disconnect clutch so as to preposition the driveline disconnect clutch or holding the clutch at an offset below stroke pressure to minimize drag.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch liftoff pressure is estimated according to a derivative of a driveline disconnect clutch pressure when a driveline disconnect clutch is being de-stroked. The driveline disconnect clutch may be prepositioned in anticipation of driveline disconnect closing based on the estimated driveline disconnect clutch liftoff pressure.

Abstract: A vehicle includes an engine, a transmission, and a controller. The transmission is configured to transfer power from the engine to at least one drive wheel to propel the vehicle. The controller programmed to, in response to a command to shift the transmission, reduce a torque of the engine from a desired engine torque to a reduced value based on a flare at an input to the transmission during the shift. The controller is further programmed to, in response to the reduced value exceeding a threshold, retard an engine spark and maintain operation of all cylinders of the engine to reduce the torque of the engine during the shift. The controller is further programmed to, in response to the reduced value being less than the threshold, retard the engine spark and shutdown at least one cylinder of the engine to reduce the torque of the engine during the shift.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, torque capacity of a driveline disconnect is adjusted in response to a change in commanded line pressure. The torque capacity of the driveline disconnect clutch may be adjusted in according to a maximum transmission line pressure.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a time duration of a boost phase of a driveline disconnect clutch closing sequence is adjusted in response to one or more error values. The error values may include pressure error, integrated pressure error, and electric machine speed error.

Abstract: Systems and methods for operating a driveline disconnect clutch of a hybrid vehicle are presented. In one example, a driveline disconnect clutch pressure is measured just prior to a request to close the driveline disconnect clutch and a time duration for driveline disconnect clutch boost pressure is adjusted in response to the measured driveline disconnect clutch pressure.

Abstract: 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.

Abstract: A vehicle includes a transmission, a powerplant, an inertial measurement unit, and a controller. The transmission has an input shaft and an output shaft. The powerplant is configured to generate and deliver torque to the input shaft. The inertial measurement unit is configured to measure inertial forces exerted onto the vehicle. The controller is programmed to, in response to a demanded torque at the output shaft and a non-transient condition of the vehicle, control the torque at the output shaft based on a torque at the input shaft and a gear ratio of the step-ratio transmission. The controller is further programmed to, in response to the demanded torque at the output shaft and a transient condition of the vehicle, control the torque at the output shaft based on the inertial forces and a vehicle velocity.

Abstract: A method of producing a disconnect clutch includes producing a disconnect clutch, configured to selectively connect an engine and an electric machine, such that the disconnect clutch exhibits a clutch transfer function that causes a transmission output shaft torque variability that is less than a predetermined threshold during a simulated starting of the engine using the electric machine.

Abstract: A vehicle includes an engine having a crankshaft, an electric machine having a rotor, a disconnect clutch having an input secured to the crankshaft and an output secured to the rotor, a hydraulic pump mechanically powered via rotation of the rotor and configured to supply hydraulic fluid to the actuate the disconnect clutch, a torque converter having an impeller secured to the rotor, and controller. The controller is programmed to, responsive to a speed of the impeller decreasing to less than a first threshold, which is indicative of a subsequent shutdown of the hydraulic pump, and responsive to the disconnect clutch being open while the engine is shut down, advance the disconnect clutch to a touch point where opposing sides of disconnect clutch make contact but substantially zero power is transferred between the engine and the electric machine.

Abstract: A method for operating a vehicle that includes a driveline disconnect clutch is described. In one example, the method includes adjusting a pressure of the driveline disconnect clutch as a function of an engine pull-up torque minus a driver demand torque when the pressure of the driveline disconnect clutch is between a torque stroke pressure and a hydraulic stroke pressure.