In a control system and a control method, an electronic control unit is configured to crank an engine by setting a clutch to a half engaged state in a state where operation of the engine is stopped during traveling. The half engaged state is a state where the clutch is engaged with a slip. The electronic control unit is configured to, after a rotation speed of the engine has reached an ignition permission rotation speed or higher, increase a transmitted torque capacity of the clutch to a transmitted torque capacity that satisfies the following conditions i) and ii): i) the transmitted torque capacity is larger than a transmitted torque capacity before the rotation speed of the engine has reached the ignition permission rotation speed; and ii) the transmitted torque capacity allows the clutch to be kept in the half engaged state.

A starting clutch control device for an automatic transmission has a starting clutch controller. The starting control device controls a transmission torque capacity of a starting clutch interposed in a transmission path in which rotation of the power source is transmitted to wheels while shifting is underway by the automatic transmission. The starting clutch controller controls the transmission torque capacity of the starting clutch such that a rotation trajectory of the power source develops as desired in a low rotation speed range in which the transmission torque capacity control of the starting clutch is necessary. The starting clutch controller causes the transmission torque capacity of the starting clutch to change, when a shift of the automatic transmission occurs during the transmission torque capacity control by the starting clutch controller, in a direction in which the change in the rotation trajectory will occur corresponding to the shift.

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.

The disclosure relates to a procedure for controlling torque transmission rate of a clutch. The clutch is in connection with a transmission and an electric machine, configured to receive torque from the electric machine by a couple half of the clutch, and configured to produce a torque guiding connection between a combustion engine and the transmission. According to the procedure, when the clutch is in a slipping condition, a shifting demand to the transmission to shift from a neutral position to a gear is detected. After detecting such a shifting demand, either a counter is started so that when the counter reaches a first count, the torque transmission rate of the clutch is being increased, or an event detection is actuated to detect an event that directly precedes the shifting process, so that when this event is detected, the torque transmission rate of the clutch is increased.

A hydraulic control system for a vehicle having a continuously variable transmission in which a torque transmitting capacity thereof is changed hydraulically, and an engagement device which is connected to the continuously variable transmission in series and in which a torque transmitting capacity thereof is changed hydraulically. The hydraulic control system comprises a selecting means that selects a command pattern for setting an engagement pressure of the engagement device out of a plurality of patterns when an initial pressure is lower than a steady pressure for a normal running of the vehicle. The selecting means is configured to select the command pattern in such a manner that the torque transmitting capacity of the engagement device does not exceeds the torque transmitting capacity of the continuously variable transmission, based on at least any of conditions of the initial pressure that is lowered to be lower than the steady pressure, and a rotational speed of the continuously variable transmission.

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.

A synchronizer system and method allow synchronization of a plurality of rotating parts by determining a measured or calculated starting relative speed of the plurality of rotating parts, and based on the starting relative speed selecting a predetermined synchronizer force profile from among a plurality of candidate profiles for synchronizing the plurality of parts prior to engagement. The selected profile is retrieved and applied to a synchronizer between the plurality of parts to be engaged, and when the relative speed between the plurality of parts to be engaged becomes substantially zero, the plurality of parts can then be engaged to one another.

A method of adjusting clutch characteristics of a Double Clutch Transmission (DCT) vehicle may include determining whether gear shifting has been initiated, updating a T-S curve of a release-side clutch by a transmission torque that is determined using an equation of motion of an engine and a clutch, when a condition in which a difference between an engine speed and a speed of a release-side input shaft is satisfied to be above a first predetermined reference value during a first reference period of time when the gear shifting is determined to have been initiated, and when a torque handover has not been initiated, updating the T-S curve of a connection-side clutch by the transmission torque that has been determined using the equation of motion during a period of time from completion of torque handover to completion of the shifting of gears.