A vehicle includes a transmission that performs a method of operating a clutch of a vehicle. The vehicle includes the clutch, an actuator device and a processor. The actuator device includes a piston movable to operate the clutch. The processor is configured to receive a pressure signal indicative of a selected fluid pressure for operating the clutch, determine a position for the piston in the actuator device from the pressure signal, and move the piston to the position to operate the clutch at the selected fluid pressure.

A hybrid vehicle includes an engine, an electric machine selectively coupled to the engine, a transmission having a torque converter impeller coupled to the electric machine and a torque converter clutch configured to selectively couple the impeller to a turbine, and a controller configured to control pressure of the torque converter clutch responsive to estimated clutch capacity, which is adjusted by the controller to equal impeller torque responsive to impeller speed exceeding turbine speed during clutch disengagement. A model of estimated torque converter clutch capacity may be stored in memory and adapted to actual clutch capacity by applying a gain or offset determined during opening of the clutch.

Accurate control is to be performed while taking an advantage of the hydraulic pressure sealing-type control. A control device of a vehicle includes a hydraulic chamber (15) into which a hydraulic pressure operating a power transmission element (10) is introduced, a first pressure regulating mechanism (35, 37) and a second pressure regulating mechanism (43) that switch hydraulic pressure in the hydraulic chamber (15), and a control device (50). The control device (50) can switch a first state in which the pressure regulating mechanism (35, 37) is in a pressure rising state and the second pressure regulating mechanism (43) is in a holding state so as to increase pressure of the hydraulic chamber, and a second state in which the second pressure regulating mechanism (43) is in a non-holding state so as to decompress the hydraulic chamber.

A method of adjusting and using operating parameters of a transmission of a vehicle may include accessing a stored list of clutch parameters, performing a dynamic condition procedure while the vehicle is driven to revise minimum on-coming apply pressure for each friction element based on a sensed performance of an element within the vehicle powertrain, storing the modified minimum on-coming apply pressures, and operating the vehicle. A related transmission control device operates a transmission using parameters obtained during a dynamic condition procedure.

A method of adjusting operating parameters of a transmission of a vehicle may include accessing a stored list of clutch parameters; performing a static condition procedure to revise the clutch parameters; and performing a dynamic condition procedure to further revise the clutch parameters. The method may be performed by a transmission control device for the vehicle, the vehicle having a powertrain including an engine, the transmission with a plurality of solenoid actuated friction elements, and sensors. The static condition procedure and dynamic procedures may be performed incrementally, and the static condition procedure may be performed more than once to fine tune the results.

Disclosed is a method of controlling a damper clutch through learning. A controller determines whether a driving condition of a vehicle is a condition where a predetermined selected fluid pressure value is desired. When necessary learning conditions are satisfied, the controller applies a control current for realizing a relevant fluid pressure to the solenoid valve. The controller updates the control current of the solenoid valve to an appropriate value based on response of the damper clutch. Thereafter, the controller controls the solenoid valve based on the updated control current.

A vehicle includes a transmission that performs a method of operating a clutch of a vehicle. The vehicle includes the clutch, an actuator device and a processor. The actuator device includes a piston movable to operate the clutch. The processor is configured to receive a pressure signal indicative of a selected fluid pressure for operating the clutch, determine a position for the piston in the actuator device from the pressure signal, and move the piston to the position to operate the clutch at the selected fluid pressure.

A method of adjusting operating parameters of a transmission of a vehicle may include accessing a stored list of clutch parameters; performing a static condition procedure to revise the clutch parameters; and performing a dynamic condition procedure to further revise the clutch parameters. The method may be performed by a transmission control device for the vehicle, the vehicle having a powertrain including an engine, the transmission with a plurality of solenoid actuated friction elements, and sensors. The static condition procedure and dynamic procedures may be performed incrementally, and the static condition procedure may be performed more than once to fine tune the results.

A system and method for determining a remaining useful life of a portion of a wet clutch system is provided. The system comprises a first clutch assembly, a proportional valve, a sensor, and a controller. The proportional valve regulates a pressure applied to the first clutch assembly. The sensor measures a response of the first clutch assembly during one of engaging and disengaging a first portion of the first clutch assembly with a second portion of the first clutch assembly. The controller controls the proportional valve, calculates a mean coefficient of friction of the first clutch assembly based on the sensed response of the first clutch assembly, and determines a remaining useful life of a portion of the wet clutch system based on the mean coefficient of friction of the first clutch assembly.

A hydraulic system for a vehicle clutch assembly can include a pump and a purge valve for regulating hydraulic pressure supplied to the clutch. The hydraulic pressure at the pump can be set to a value higher than the operating pressure for the clutch. The purge valve can be configured to purge hydraulic pressure from the hydraulic system so that an optimum, controllable, and/or pre-determined operating pressure can be supplied to the clutch. The system can be configured to provide accurate control of the clutch(es), continuous cooling capacity to the hydraulic system components, lateral torque control when two separate hydraulic circuits are used, weight and cost reduction of the vehicle clutch, as well as other vehicle functions and characteristics.