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.

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.

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 sets a predefined position of a clutch actuator comprising a friction spring element. An activation path of the clutch actuator that actuates the clutch is predefined by a coupling torque via a coupling characteristic curve, wherein the predefined position (zo, zu) to be assumed by the clutch actuator is set by a closed-loop controller. To enable the predefined position of the clutch actuator to be set precisely without using additional energy, the predefined position (zo, zu) is corrected by a turning back value (ro, ru) of the friction spring element and the corrected position (zo+ro; zu−ru) of the clutch actuator is approached by the closed-loop controller. After reaching the corrected position (zo+ro; zu−ru) the closed-loop controller is switched off by dissipating the potential energy stored in the friction spring element.

A method for determining a kiss point is disclosed. A drive unit having one or more motors with a motor output shaft is provided. One or more actuation profiles are ran and an amount of motor current and motor shaft position data is measured. The data measured is filtered and one or more motor current vs. motor shaft position plots having one or more curves with a high force and high current region are generated. A derivative is calculated over the curves and a slope of the high force and high current region is determined. A relative slope threshold is determined by multiplying the slopes by a predetermined percentage. One or more lines having a slope substantially equal to the relative slope threshold are plotted. The kiss point is determined based on the position of the motor shaft where the derivative of the curves equals the slope of the lines plotted.

A method sets a predefined position of a clutch actuator comprising a friction spring element. An activation path of the clutch actuator that actuates the clutch is predefined by a coupling torque via a coupling characteristic curve, wherein the predefined position (zo, zu) to be assumed by the clutch actuator is set by a closed-loop controller. To enable the predefined position of the clutch actuator to be set precisely without using additional energy, the predefined position (zo, zu) is corrected by a turning back value (ro, ru) of the friction spring element and the corrected position (zo+ro; zu−ru) of the clutch actuator is approached by the closed-loop controller. After reaching the corrected position (zo+ro; zu−ru) the closed-loop controller is switched off by dissipating the potential energy stored in the friction spring element.

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 determining a kiss point is disclosed. A drive unit having one or more motors with a motor output shaft is provided. One or more actuation profiles are ran and an amount of motor current and motor shaft position data is measured. The data measured is filtered and one or more motor current vs. motor shaft position plots having one or more curves with a high force and high current region are generated. A derivative is calculated over the curves and a slope of the high force and high current region is determined. A relative slope threshold is determined by multiplying the slopes by a predetermined percentage. One or more lines having a slope substantially equal to the relative slope threshold are plotted. The kiss point is determined based on the position of the motor shaft where the derivative of the curves equals the slope of the lines plotted.

A method for determining a kiss point. A drive unit having one or more motors with a motor output shaft is provided. One or more actuation profiles are ran and an amount of motor current and motor shaft position data is measured. The data measured is filtered and one or more motor current vs. motor shaft position plots having one or more curves with a high force and high current region are generated. A derivative is calculated over the curves and a slope of the high force and high current region is determined. A relative slope threshold is determined by multiplying the slopes by a predetermined percentage. One or more lines having a slope substantially equal to the relative slope threshold are plotted. The kiss point is determined based on the position of the motor shaft where the derivative of the curves equals the slope of the lines plotted.

A method for determining a kiss point. A drive unit having one or more motors with a motor output shaft is provided. One or more actuation profiles are ran and an amount of motor current and motor shaft position data is measured. The data measured is filtered and one or more motor current vs. motor shaft position plots having one or more curves with a high force and high current region are generated. A derivative is calculated over the curves and a slope of the high force and high current region is determined. A relative slope threshold is determined by multiplying the slopes by a predetermined percentage. One or more lines having a slope substantially equal to the relative slope threshold are plotted. The kiss point is determined based on the position of the motor shaft where the derivative of the curves equals the slope of the lines plotted.