A calibration method for a slip control arrangement of a driveline including a continuously variable transmission is described herein. The driveline includes a clutch that is so controlled as to slip when a torque higher than the usable torque attempts to pass through. Accordingly, the clutch prevents the prime mover from stalling. A calibration method to link a valve command value and a torque allowed to pass through the clutch includes preventing the vehicle from moving and increasing the pressure applied in the clutch while noting the torque % value developed by the prime mover.

The invention relates to a method for determining an engagement point of a hybrid clutch in a hybrid vehicle; which hybrid clutch is actuated by a hydrostatic clutch actuator and disconnects or connects an internal combustion engine and an electric traction drive; the engagement point is determined by slowly actuating the clutch starting from a position in which the hybrid clutch is in the non-actuated state, and monitoring a moment of the electric traction drive when a defined increase in the momentum is detected. In a method in which engagement point adaptation is optimized, a current engagement point (tp) is adapted during operation of the hybrid vehicle using a start-up routine, by which a first engagement point is determined when the hybrid vehicle is started; the hybrid clutch is moved close to a previously determined engagement point, and starting from said last determined engagement point, the hybrid clutch is displaced further until the defined increase in the moment is detected.

An initial variation learning control is executed when a learning condition is satisfied each time the learning condition is satisfied, with the aim of absorbing initial variations of manufacturing errors or variations of components of a second clutch (CL2). When the number of times of learning control is counted and this becomes a predetermined number (e.g. five times), after that, a deterioration variation learning control, which is equivalent to the initial variation learning control, is executed only once a trip from ON of a key switch to OFF of the key switch. With this, a frequency of execution of the learning control can be reduced, and the number of times of the learning can be reduced. It is therefore possible to suppress energy consumption and improve energy efficiency in stand-by pressure learning control of the second clutch that serves as a starter clutch.

A method for learning an engine clutch kiss point of a hybrid vehicle includes: controlling, by a controller, an engine clutch which connects an engine with a motor or disconnects the engine from the motor so that the engine clutch is engaged after the controller checks stop of the engine and of the motor and stabilization operation for a hydraulic pressure line of the engine clutch is performed; controlling the motor to have a certain speed after the stabilization operation; controlling the engine clutch to be engaged after speed of the motor is stabilized; determining whether torque variation of the motor when the engine clutch is engaged is equal to or greater than a threshold value; and determining a hydraulic pressure at which the torque variation is the threshold value as the kiss point of the engine clutch.

A method for learning an engine clutch kiss point of a hybrid vehicle includes: controlling, by a controller, an engine clutch which connects an engine with a motor or disconnects the engine from the motor so that the engine clutch is engaged after the controller checks stop of the engine and of the motor and stabilization operation for a hydraulic pressure line of the engine clutch is performed; controlling the motor to have a certain speed after the stabilization operation; controlling the engine clutch to be engaged after speed of the motor is stabilized; determining whether torque variation of the motor when the engine clutch is engaged is equal to or greater than a threshold value; and determining a hydraulic pressure at which the torque variation is the threshold value as the kiss point of the engine clutch.

A method for learning an engine clutch kiss point of a hybrid vehicle includes: determining whether a kiss point learning condition of an engine clutch which connects an engine with a motor or disconnects the engine from the motor is satisfied; controlling a speed of the motor to a first speed; learning a first kiss point of the engine clutch by engaging the engine clutch so that the motor having the first speed is connected to the engine; controlling the speed of the motor to a second speed; learning a second kiss point of the engine clutch by engaging the engine clutch so that the motor having the second speed is connected to the engine; and selecting an average value of the first kiss point and the second kiss point as the engine clutch kiss point when a standard deviation thereof does not exceed a threshold value.

The invention relates to a method for determining an engagement point of a hybrid clutch in a hybrid vehicle; which hybrid clutch is actuated by a hydrostatic clutch actuator and disconnects or connects an internal combustion engine and an electric traction drive; the engagement point is determined by slowly actuating the clutch starting from a position in which the hybrid clutch is in the non-actuated state, and monitoring a moment of the electric traction drive when a defined increase in the momentum is detected. In a method in which engagement point adaptation is optimized, a current engagement point (tp) is adapted during operation of the hybrid vehicle using a start-up routine, by which a first engagement point is determined when the hybrid vehicle is started; the hybrid clutch is moved close to a previously determined engagement point, and starting from said last determined engagement point, the hybrid clutch is displaced further until the defined increase in the moment is detected.

A method for learning a touch point of an engine clutch for a hybrid electric vehicle includes controlling a speed of an engine to have an idle speed. A fluid pipe of a clutch actuator is refilled with a working fluid by driving a driving motor in an idle control state of the engine, a speed of the driving motor is synchronized with the speed of the engine, and then the engine clutch is engaged. The engine clutch is released after the refill is performed, and the speed of the driving motor is decreased. A working fluid is applied so that the engine clutch is operated in an engagement direction by operating the clutch actuator, and a state change of the driving motor is detected. The touch point of the engine clutch is determined based on the state change of the driving motor.

Methods are provided for checking the actuating accuracy of a clutch arranged in a force flow between a fixable shaft and an electric machine of an electric or hybrid motor vehicle when at a standstill. One method includes: fixing the shaft, setting a defined setpoint torque on the clutch to be checked, continuously ramping up the electric machine up until the first slipping of the clutch, comparing the achieved torque of the electric machine with the setpoint torque preset on the clutch. Another method includes: fixing the shaft, ramping up the electric machine to a defined rotational speed, setting a defined setpoint torque on the clutch to be checked, comparing the torque of the electric machine needed to maintain a constant rotational speed with the setpoint torque set on the clutch.