Abstract: A method and a system for improving operation of a hybrid vehicle are presented. In one example, operation of a hybrid driveline is adjusted in response to driving conditions that may cause wheel slip or a stuck vehicle. The approach may reduce driveline wear and improve vehicle drivability.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, negative torque of an electric machine is adjusted to mimic negative torque of an engine during engine braking so that the vehicle may transition from regenerative braking to engine braking in a seamless manner.

Abstract: Systems and methods for improving operation of a power take off are presented. In one example, the power take off may be rotated in two different directions. The approaches may improve operation of a power take off device.

Abstract: A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided. Measured torque values are used during a torque phase of the upshift to correct an estimated oncoming friction element target torque so that transient torque disturbances at an oncoming clutch are avoided and torque transients at the output shaft are reduced.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, torque demand of a driveline after a shift is forecast to determine if it is desirable to start the engine early so that engine torque is available after the shift. The approach may improve vehicle torque response.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, application of a driveline disconnect clutch to start an engine is described. The approach applies the driveline disconnect clutch to rotate an engine and at least partially disengages the driveline disconnect clutch to reduce the possibility of a reduction in torque applied to vehicle wheels.

Abstract: Methods and systems are provided for pressurizing a transmission hydraulic circuit including a transmission mechanical pump coupled to an engine though a gearbox. One example method comprises, during an engine start, adjusting a speed ratio between the transmission pump and the engine between a first speed ratio and a second speed ratio, the pump rotating faster relative to the engine at the first speed ratio as compared with the second speed ratio. In this way, the pump may be driven at different speed ratios relative to the engine to provide better pressurization in the transmission.

Abstract: Designs to package a magneto-elastic torque sensor in an automotive transmission for volume production applications are provided. One transmission includes an output shaft and a magnetic torque sensor. The output shaft has a magnetized region. The sensor, for detecting torque of the output shaft, is mounted on friction reduction members such as bushings supporting the output shaft. In another transmission, the sensor is alternatively mounted to a transmission case.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, driveline operation may be adjusted in response to operating the hybrid vehicle in a four wheel drivel low gear range. The approaches may improve vehicle drivability and reduce driveline degradation.

Abstract: A calibration method includes obtaining in-vehicle measured clutch torques at a set of shift conditions; performing a series of bench tests at various clutch pack clearances and lubrication oil flow rates at the set of shift conditions; adjusting clutch pack clearances and lubrication oil flow rates during the series of bench tests in response to a difference between a bench test measured clutch torques and the corresponding in-vehicle measured clutch torques exceeding a threshold; and recording relationships between first bench test measured torques and force profiles of a clutch actuator relative to the adjusted clutch pack clearances and lubrication oil flow rates for each of the set of shift conditions as a first transfer function in response to the difference between the first bench test measured clutch torques and the in-vehicle clutch torques not exceeding the threshold for each of the set of shift conditions.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, a driveline disconnect clutch transfer function may be adapted in response to engine operating conditions during closing of the driveline disconnect clutch.

Abstract: A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated friction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided. Measured torque values are used during a torque phase of the upshift to correct an estimated oncoming friction element target torque so that transient torque disturbances at an oncoming clutch are avoided and torque transients at the output shaft are reduced.

Abstract: A multiple ratio transmission having an input shaft, an output shaft and oncoming clutch and off-going clutch for effecting ratio upshifts is provided. The transmission also includes a transmission controller configured for controlling shifts. During the torque phase of a ratio upshift, the controller increases input torque. Next, the controller estimates an oncoming clutch target torque. The controller controls a torque input to ensure the off-going clutch remains locked. The controller measures an actual transmission value for a torque transmitting element of the transmission and corrects the oncoming clutch target torque using the actual transmission value whereby an increasing torque for the oncoming friction element is achieved with minimal torque transients along the output shaft during the upshift.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, application of a driveline disconnect clutch to start an engine is described. The approach applies the driveline disconnect clutch to rotate an engine and at least partially disengages the driveline disconnect clutch to reduce the possibility of a reduction in torque applied to vehicle wheels.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, driveline braking may transition from regenerative braking to engine braking to reduce the possibility of battery degradation.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, operation of a driveline disconnect clutch is adjusted to compensate for clutch wear and manufacturing tolerances.

Abstract: A multiple ratio transmission having an input shaft, an output shaft and oncoming clutch and off-going clutch for effecting ratio upshifts is provided. The transmission also includes a transmission controller configured for controlling shifts. During the torque phase of a ratio upshift, the controller increases input torque. Next, the controller estimates an oncoming clutch target torque. The controller controls a torque input to ensure the off-going clutch remains locked. The controller measures an actual transmission value for a torque transmitting element of the transmission and corrects the oncoming clutch target torque using the actual transmission value whereby an increasing torque for the oncoming friction element is achieved with minimal torque transients along the output shaft during the upshift.

Abstract: A hydraulically actuated clutch is controlled based on a mathematical model that predicts the position of the clutch piston based on the profile of the commanded pressure over time. During a clutch engagement, a set of delays associated with the preparatory phase of engagement are measured and compared to predicted values. Model parameters are then adaptively adjusted based on the differences between the measured and predicted delays and on an estimate of the sensitivities between model parameters and the delays. Subsequent engagements are controlled based on the updated mathematical model to reduce the delays. Changes in the measured delays following adaptation of the model parameters are utilized to update the estimate of the sensitivities.

Abstract: Methods and systems are provided for controlling a vehicle engine coupled to a stepped-gear-ratio transmission. One example method comprises, in response to a first vehicle moving condition, shutting down the engine and at least partially disengaging the transmission while the vehicle is moving; and during a subsequent restart, while the vehicle is moving, starting the engine using starter motor assistance and adjusting a degree of engagement of a transmission clutch to adjust a torque transmitted to a wheel of the vehicle.

Abstract: Systems and methods for improving operation of a hybrid vehicle are presented. In one example, driveline braking may transition from regenerative braking to engine braking to reduce the possibility of battery degradation.