Piston apparatus for use with vehicle clutches are disclosed. A disclosed drive unit assembly for a vehicle includes a housing defining a first cavity and a second cavity fluidly coupled together. The drive unit assembly also includes a clutch positioned in the first cavity. Rotation of the clutch conveys a fluid from the first cavity to the second cavity. The drive unit assembly also includes a port extending from the second cavity to the first cavity to receive the fluid. The drive unit assembly also includes a piston positioned in the first cavity proximate to the port and configured to operate the clutch. Movement of the piston relative to the port controls a flow of the fluid through the port from the second cavity to the first cavity.

A controller for a vehicle driven by transmitting a torque generated by a torque generator to driving wheels corrects the torque generated by the torque generator according to a torsion rate of an elastic torsion element present in a torque transmission system extending from the torque generator to the driving wheels to reduce the torsional vibration of the elastic torsion element. The torque generator may include an engine and a clutch to transmit a rotation of the engine to the torque transmission system. The controller may include a clutch controller to correct the torque generated by the torque generator by controlling the transmission torque of the clutch according to the torsion rate of the elastic torsion element.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, the engine is started and coupled to the driveline via closing a clutch of a dual clutch transmission. Speed of the engine and clutch pressure are controlled to reduce driveline torque disturbances and provide a desired wheel torque.

Piston apparatus for use with vehicle clutches are disclosed. A disclosed drive unit assembly for a vehicle includes a housing defining a first cavity and a second cavity fluidly coupled together. The drive unit assembly also includes a clutch positioned in the first cavity. Rotation of the clutch conveys a fluid from the first cavity to the second cavity. The drive unit assembly also includes a port extending from the second cavity to the first cavity to receive the fluid. The drive unit assembly also includes a piston positioned in the first cavity proximate to the port and configured to operate the clutch. Movement of the piston relative to the port controls a flow of the fluid through the port from the second cavity to the first cavity.

Hydraulic-oil control devices are provided herein that perform hydraulic-oil supply control in a dual clutch device having a first clutch and a second clutch. A hydraulic-oil control device according to embodiments herein includes a first linear solenoid valve that adjusts hydraulic oil having a line pressure for a first hydraulic chamber and supplies the hydraulic oil thereto, a second linear solenoid valve that adjusts hydraulic oil having a line pressure for a second hydraulic chamber and supplies the hydraulic oil thereto, a shuttle valve that outputs the hydraulic oil having a higher pressure between the pressure of the hydraulic oil in the first hydraulic chamber and the pressure of the hydraulic oil in the second hydraulic chamber, and a switch valve that adjusts the amount of hydraulic oil supplied to a first space and a second space, according to the pressure of the hydraulic oil output from the shuttle valve.

A clutch hydraulic control method and the double clutch transmission system may include performing a clutch pack flow rate control, which pre-fills a flow rate for clutch engage in a clutch pack of a clutch before shifting, when a shifting attempt is detected in a clutch controller.

A clutch torque estimating method for a transmission of a vehicle may include inputting model engine torque to a powertrain model by a controller; inputting target clutch torque of a first clutch and target clutch torque of a second clutch to the powertrain model by the controller; inputting shifting information related to the vehicle to the powertrain model by the controller; correcting the powertrain model in real time by feeding back an engine angular velocity error, a clutch angular velocity error of the first clutch, a clutch angular velocity error of the second clutch, a wheel angular velocity error to the powertrain model by the controller; and estimating clutch torque of the first clutch and clutch torque of the second clutch by determining the powertrain model by the controller.

A method (200) for the open-loop control of a gearbox (100) that includes a first and a second proportionally controllable shift element (A-F) is provided. The method includes disengaging (215) the first shift element (A-F) according to a first control profile and engaging (220) the second shift element (A-F) of the gearbox (100) according to a second control profile. The first control profile includes a first variable portion which is determined as a function of a temperature of the gearbox (100).

A transmission includes a selectable one-way clutch with active and passive states. Successful transition from the active state to the passive state is only possible when there is no torque tending to cause overrunning. After commanding a transition from the active state to the passive state, a controller partially engages a first friction clutch to induce a torque tending away from overrunning until a lash crossing is detected. Then, the controller releases the first clutch and partially applies a second clutch to induce a torque toward overrunning. When slip is detected, indicating successful achievement of the passive state, the second clutch is released.

A method of controlling an input clutch and an output clutch, wherein the input clutch couples to a power source, the output clutch couples to a load, and the input clutch couples to the output clutch via gears, includes controlling torque of the input clutch based on a torque of the output clutch or a lookup table that controls the torque of the output clutch. The method also includes adjusting the torque of the input clutch based on a slip speed of the input clutch and a slip speed of the output clutch.