Method for determining a kisspoint of a clutch. A method is provided of determining a kisspoint of a clutch in a driveline of a vehicle comprising a. increasing a target clutch pressure of a clutch piston up to a first predetermined test target pressure, b. increasing the target clutch pressure up to an upper target pressure and subsequently keeping the target clutch pressure stable for a predetermined time interval, c. monitoring a parameter indicative for the filling of the clutch piston, e.g. the rotational speed of a pump, during the predetermined time interval, d. repeating steps a., b., and c. for at least one further predetermined test target pressure, and e. determining the kisspoint based on the monitored parameter indicative for the filling of the clutch piston.

A method for operating a hydraulic actuator for a prime mover or a drive device of a vehicle includes determining that the hydraulic actuator is to be actuated via an actuating system and detecting an operating variable influenced by a filling state of the hydraulic actuator indicative of pressure conditions in the hydraulic actuator, with the operating variable being separate from actuator operating variables of the hydraulic actuator and the actuating system. The method further includes pressurizing the actuator during a fast fill phase to one or more pressures over a fast fill time period in response to determining that the hydraulic actuator is to be actuated. The fast fill time period and the one or more pressures are adjusted as a function of the operating variable under certain operating conditions. Additionally, the method includes pressurizing the actuator during a pressure build-up phase after the fast fill phase.

A hydraulic control device for a vehicle is provided wherein a determination of “base neutral” is made when a difference between a command hydraulic pressure and an actual hydraulic pressure of a hydraulic clutch is within a predetermined minute value range, and when the difference is out of the minute value range, a determination of “base raising” is made if the command hydraulic pressure is larger than the actual hydraulic pressure, and a determination of “base lowering” is made if the command hydraulic pressure is smaller than the actual hydraulic pressure. The determination of “sub raising” is made when an inclination of command torque subjected to low-pass filter processing is positive for a predetermined time or more, and the determination of “sub lowering” is made when the inclination is negative for the predetermined time or more, whereby a rising or dropping tendency of the command torque is determined.

A work vehicle includes a rotary member, a support member, a sealing ring, a pressure controller, and a vehicle speed determination component. The rotary member has a first hydraulic fluid supply channel to supply the hydraulic fluid to the steering clutch, and is rotated by power from the transmission when the steering clutch is engaged. The sealing ring is disposed between the rotary member and the support member and is mounted adjacent to the connected part between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel. The pressure controller controls the engagement pressure to be a specific first pressure when the vehicle speed is determined not to be equal to or greater than a specific speed, and controls the engagement pressure to decrease from the first pressure when the vehicle speed is determined to be equal to or greater than a specific speed.

A control unit for controlling a motor of an oil pump. The control unit includes a receiving unit configured to receive a target pressure, a first determination unit configured to determine a torque from the target pressure and a speed of the motor via a first characteristic map, a second determination unit configured to determine a motor phase current from the determined torque via a second characteristic map, and an output unit configured to output the determined motor phase current.

A line pressure control method for a double clutch transmission (DCT) includes estimating a line pressure, which decreases with stoppage of an electric oil pump, based on a linear regression model using state variables of the DCT that are related to a line pressure change, and driving the electric oil pump when the line pressure estimated based on the linear regression model reaches a predetermined lower limit.

Systems and methods of controlling a clutch in a vehicle are provided. With the goal of enabling autonomous/assisted control of the clutch by an electronic control unit while preserving the familiar mechanical feeling at the clutch pedal that driving enthusiasts prefer, embodiments of the disclosed technology use a shuttle valve to blend control of clutch engagement between a driver and an ECU. In these embodiments, a clutch pedal in the vehicle may be mechanically connected to a piston in a first hydraulic cylinder (just like in a traditional mechanical/hydraulic clutch actuation system), and an ECU may actuate a second hydraulic cylinder. Accordingly, a shuttle valve may be used to route the fluid coming from the cylinder with the greater pressure (i.e. the driver actuated cylinder or the ECU actuated cylinder), to a third hydraulic cylinder which adjusts engagement of a clutch by a mechanical linkage.

A method for automatically warming up a clutch actuator for a clutch of a transmission in a vehicle, wherein the clutch actuator is operable by use of pressurized fluid and configured to actuate the clutch from an engaged to a disengaged state, and/or vice versa, the method including: identifying if a temperature is below a predetermined temperature value and if the clutch actuator is leaking, and if it is identified that the temperature is below the predetermined temperature value and that the clutch actuator is leaking; then repeatedly pressurizing the clutch actuator by use of the pressurized fluid until a state is reached indicative of the clutch actuator being functional, or until a maximum run out state is reached indicative of a faulty clutch actuator.

An apparatus of controlling a twin clutch includes: a twin clutch that selectively blocks power supplied from a drive motor to a pair of drive wheels of a vehicle; and a clutch controller that is configured to control the twin clutch by determining target torques applied to respective clutches included in the twin clutch, based on the straight-line driving state detected by the driving information detection unit, determining a correction error based on a difference between actual torques applied to the respective clutches included in the twin clutch when a preliminary activation signal, which is determined based on the target torques, is turned on and a main activation signal, which is determined based on the actual torques applied to the respective clutches, is turned on, determining a balancing control compensation amount based on the correction error, and determining a final control amounts applied to the respective clutches based on the balancing control compensation amount.

Methods and systems for a transmission are provided. The method includes estimating a stroke position of the hydraulic control piston based on a pressure of a fluid in a hydraulic line and a valve and a coefficient of the hydraulic line, where the hydraulic line is coupled to a chamber of the hydraulic control piston. The method further includes controlling a pressure of fluid delivered from the valve to the hydraulic control piston based on the estimated stroke position to achieve a piston stroke set-point during a filling phase.