Abstract: A hybrid vehicle includes an engine, an electric machine, a disconnect clutch configured to selectively couple the engine to the electric machine, a transmission having an input shaft operably coupled to the electric machine and an output shaft operably coupled to a driveline, and a controller programmed to, in response to (i) the disconnect clutch being disengaged and (ii) a speed difference between the input and output shafts being less than a threshold, limit torque commanded to the electric machine to a value that is less than a rated torque of the electric machine regardless of driver-demand torque, and further programmed to, in response to (i) the disconnect clutch being disengaged, (ii) a request to start the engine, and (iii) the speed difference exceeding the threshold, permit a torque command to the electric machine that exceeds the value to reduce the speed difference between the input and output shafts.

Abstract: Systems and methods for managing starting of an internal combustion engine during shifting of a transmission of a hybrid vehicle are presented. In one example, torque converter impeller speed or a torque multiplication ratio may be indicative of an unintended transmission downshift during engine starting so that an engine starting device may be switched to improve vehicle operation.

Abstract: Systems and methods for operating a driveline of a hybrid vehicle are presented. In one example, the systems and methods adjust a driveline disconnect clutch boost time duration or magnitude responsive to a pressure error and a time delay error. A driveline disconnect clutch may be operated via supplying a pressure to the driveline disconnect clutch that includes the adjusted boost time duration or magnitude.

Abstract: A vehicle includes an engine, an electric machine, a disconnect clutch, a starter motor, and a controller. The engine and electric machine are each configured to generate power to propel the vehicle. 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, operate either the disconnect clutch or the starter motor to start the engine based on a level of adaptive learning of previous disconnect clutch engagements.

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 vehicle includes an engine, an electric machine, a disconnect clutch, a starter motor, and a controller. The engine and electric machine are each configured to generate power to propel the vehicle. 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, operate either the disconnect clutch or the starter motor to start the engine based on a level of adaptive learning of previous disconnect clutch engagements.

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: 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, an electric machine, a clutch, and a controller. The clutch is disposed between the engine and the electric machine. The controller is programmed to, in response to an engine start, close the clutch to transfer power from the electric machine to the engine to start the engine. The controller is further programmed to, in response to the engine start, control a torque capacity of the clutch during the engine start according to a model of a pressure applied to the clutch. The controller is further programmed to, in response to the engine start, control the torque of the electric machine based on an adjusted torque capacity of the clutch.

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 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 selecting and scheduling which of a plurality of engine starting devices starts an internal combustion engine of a hybrid vehicle are presented. In one example, a scheduled start of the internal combustion engine via a driveline disconnect clutch is withdrawn during conditions when both a transmission gear shift is requested or in process and when a driver urgency level is greater than a threshold level.

Abstract: Systems and methods for managing starting of an internal combustion engine during shifting of a transmission of a hybrid vehicle are presented. In one example, torque converter impeller speed or a torque multiplication ratio may be indicative of an unintended transmission downshift during engine starting so that an engine starting device may be switched to improve vehicle operation.

Abstract: Systems and methods for selecting and scheduling which of a plurality of engine starting devices starts an internal combustion engine of a hybrid vehicle are presented. In one example, a scheduled start of the internal combustion engine via a driveline disconnect clutch is withdrawn during conditions when both a transmission gear shift is requested or in process and when a driver urgency level is greater than a threshold level.

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, the systems and methods may adjust a relationship (e.g., transfer function) between an amount of electric current that is supplied to a driveline disconnect clutch control valve and a commanded driveline disconnect clutch pressure.