A continuously variable transmission (CVT) including a hydraulically-controllable variator is described. A method for controlling the CVT includes detecting a transient event causing a commanded change in a speed ratio of the variator and disabling feedback control of hydraulic pressure to the variator during the transient event. A target pressure that achieves the commanded change in the speed ratio of the variator is determined, and a pressure trajectory is determined based upon the target pressure. A feed-forward control of the hydraulic pressure to the variator is executed in response to the pressure trajectory during the transient event.

A powertrain system including a continuously variable transmission (CVT) is described. A method for controlling the CVT includes determining a target clamping pressure and an actual clamping pressure, and determining a proportional correction term and an integral correction term based upon the target clamping pressure and the actual clamping pressure. An adapt correction term is determined based upon the target clamping pressure and a temperature of the CVT. A commanded clamping pressure for controlling the CVT is determined based upon the proportional correction term, the integral correction term and the adapt correction term. A pressure command is employed to drive an actuator of a moveable sheave of a pulley of a variator of the CVT based upon the commanded clamping pressure.

A method controls synchronization of a pinion rotating on a primary shaft driven by a traction machine of a vehicle and rotatably connected to a secondary shaft of a parallel shaft gearbox without synchronization mechanisms. The method includes sending to the traction machine, before coupling of the pinion on the primary shaft, a torque command which depends on a torque signal calculated to minimize a difference between a primary speed and a secondary speed multiplied by a reduction ratio between the primary shaft and the secondary shaft. The calculated torque signal is limited in amplitude when the speed difference is greater in absolute value than a desired accuracy on the targeted primary speed upon completion of the synchronization. The calculated torque signal is saturated on a maximum or minimum torque of the traction machine if the calculated torque signal is not between the maximum or minimum torque.

A control device for controlling a hydraulic pressure of a fluid transmission includes a pressure sensor for detecting actual pressure values of the hydraulic pressure, an electronic control unit for generating a control signal as a function of the actual pressure values detected by the pressure sensor and a reference pressure signal delivered to the control unit, a power switch controlled by the control signal and a solenoid valve actuated by the power switch for generating the hydraulic pressure. The control device is configured as a compact electromagnetic unit. The electronic control unit is respectively connected to the pressure sensor and to the power switch by a direct electrical connection. A method for controlling a hydraulic pressure of a fluid transmission is also provided.