A method for operating an electrohydraulic transmission clutch of a motor vehicle, wherein, for a clutch operation, a hydraulic pressure is set by way of a regulating device of a controller as a function of a clutch signal, and, through the pressure, a disengagement element of the transmission clutch is moved through a soft region into a rigid region via a rigid point, or vice versa. The soft region is to be compensated for. Further, as a function of the clutch signal, the regulating device generates a preliminary target value signal for the pressure and a time derivative of the preliminary target value signal is generated as a movement signal, and a pilot control generates a pilot control signal as a function of the movement signal, and the preliminary target value signal and the pilot control signal are combined to give a final actuating value signal for the pressure.

A method for controlling an actuator includes providing the actuator with a control unit, a drive unit including an electric motor with a stator and a rotor, a rotor position sensor, connected to the control unit, for detecting a rotation of the rotor, and a displacer unit, drivable by the rotation of the rotor, for displacing a fluid. The displacer unit includes a geometric displacement volume per revolution of the rotor. The method also includes generating a predetermined pressure at the displacer unit by applying an electrical driving power to the electric motor, maintaining the predetermined pressure over a predetermined time interval, determining the rotation of the rotor with the rotor position sensor during the predetermined time interval, and determining a leakage volume flow.

Various methods and systems are provided for a multispeed transmission. In one example, a method to increasing a shift performance of a transmission with actuated clutches comprises controlling an engagement depth of a clutch based on a gear that is being selected by the clutch. A target engagement depth of the clutch may be retrieved from a gear selection matrix in a lookup table stored in the memory of a controller of the transmission. The target engagement depth may depend on an amount of torque expected to be transferred to the gear.

A method for adjusting a clutch characteristic curve, including obtaining a torque-stroke learning value for adjusting the clutch characteristic curve, calculating a convergence value for each control point of the clutch characteristic curve, calculating a difference value between the convergence value and a characteristic curve value for each control point, and determining a new characteristic curve value of each control point according to whether a maximum value of the calculated difference values exceeds a preset reference value.

A method for operating a dual-clutch transmission with two clutches. During realization of a ratio, a first clutch is closed and a second clutch is open. During a ratio change, the first clutch is opened and the second clutch is closed. During a ratio change within short operating times, a target actuating pressure of the clutch for engagement is set to a fast-charging pressure level and subsequently adjusted to a closing pressure level, while a target actuating pressure of the clutch for disengagement is adjusted to an opening pressure level before setting the closing pressure level of the clutch for engagement. At least during a ratio change, an actual actuating pressure of the clutch for engagement is monitored and the target actuating pressure of the clutch for disengagement is adjusted to the opening pressure level if the actual actuating pressure of the clutch for engagement exceeds a pressure threshold.

Provided herein is a method for calibrating a clutch by searching for the minimum of a multi-dimensional surface including determining the error between a spline function and recorded data relating to clutch characteristics, creating a multi-dimensional surface corresponding to the error values, determining the minimum of the multi-dimensional surface using the steps of performing a Steepest Gradient & Direction determination step and conducting a Golden Section Search and Switch Direction Step to find a minimum that meets a predetermined closing condition. Additionally, provided herein is a computer-implemented system for calibrating the clutch.

Various methods and systems are provided for a multispeed transmission. In one example, a method to increasing a shift performance of a transmission with actuated clutches comprises controlling an engagement depth of a clutch based on a gear that is being selected by the clutch. A target engagement depth of the clutch may be retrieved from a gear selection matrix in a lookup table stored in the memory of a controller of the transmission. The target engagement depth may depend on an amount of torque expected to be transferred to the gear.

A T-S curve correction method for a clutch system may include: detecting differences between actual positions of a clutch in first and second torque regions and a position on a T-S curve; determining whether the difference between the actual position in the first torque region and the position on the T-S curve is equal to or more than a first reference value; determining whether the difference between the actual position in the second torque region and the position on the T-S curve is equal to or less than a third reference value, when the difference of the actual position in the first torque region is equal to or more than the first reference value; and correcting the slope of the T-S curve in the increasing direction, when the difference of the actual position in the second torque region is equal to or less than the third reference value.

A method for operating a dual-clutch transmission with two clutches. During realization of a ratio, a first clutch is closed and a second clutch is open. During a ratio change, the first clutch is opened and the second clutch is closed. During a ratio change within short operating times, a target actuating pressure of the clutch for engagement is set to a fast-charging pressure level and subsequently adjusted to a closing pressure level, while a target actuating pressure of the clutch for disengagement is adjusted to an opening pressure level before setting the closing pressure level of the clutch for engagement. At least during a ratio change, an actual actuating pressure of the clutch for engagement is monitored and the target actuating pressure of the clutch for disengagement is adjusted to the opening pressure level if the actual actuating pressure of the clutch for engagement exceeds a pressure threshold.

The present disclosure provides a clutch control method of a hybrid vehicle of the including an entering condition determining step in which a controller determines whether shifting is being performed during regenerative braking; an error calculating step in which the controller calculates a torque error by subtracting observer torque, which is clutch transfer torque calculated by a clutch torque estimator receiving transmission input torque and motor speed, from map torque, which is clutch transfer torque calculated based on a clutch transfer torque map for clutch actuator strokes learned in advance, when shifting is being performed during regenerative braking; a correcting step in which the controller corrects the clutch transfer torque map for the clutch actuator strokes using the torque error calculated in the error calculating step; and a clutch control step in which the controller controls a clutch using the map corrected in the correcting step.