A method of controlling a dual clutch transmission, may include releasing a pressure of a non-driveshaft clutch and engaging a gear of a non-driveshaft; applying a first pressure to the non-driveshaft clutch and disengaging the gear of the non-driveshaft; determining a drag torque on the basis of a first rotation speed change rate of the non-driveshaft; releasing the first pressure and engaging the gear of the non-driveshaft; applying a second pressure to the non-driveshaft clutch and disengaging the gear of the non-driveshaft; determining a touch point torque on the basis of a second rotation speed change rate of the non-driveshaft; and adjusting a touch point of the non-driveshaft clutch on the basis of a net torque which is a difference between the touch point torque and the drag torque.

Provided is a method of learning a touch point of a dual clutch transmission (DCT), and more particularly, to a DCT touch point learning method in which a touch point is learned based on a difference between a virtual input shaft speed and a clutch non-drive shaft input speed using a virtual input shaft reference speed calculated based on the speed of a traveling vehicle. In a traveling situation in which the touch point cannot be learned using the non-drive shaft according to the related art because the input shaft behavior of the non-drive shaft is rotationally synchronized with the input shaft behavior of the drive shaft by drag characteristics of the DCT, a virtual input shaft speed may be calculated, and the touch point of the clutch may be learned using the virtual input shaft speed.

A method for determining reference values of a sensor corresponding to a disengaged operating condition or to an engaged operating condition of a hydraulically actuatable, form-locking shift element (A, F), where at least one operating parameter of the form-locking shift element (A, F) is detected with the sensor during a disengagement and during an engagement of the form-locking shift element (A, F). The method may include subdividing an operating range of the shift form-locking element (A, F) into temperature and pressure classes. The method may further include determining a deviation between a current reference value for a temperature and pressure class of the temperature and pressure classes and an adapted reference value previously determined for the temperature and pressure class. Additionally, the method may include increasing or decreasing the adapted reference value by a predefined increment based on the deviation.

A clutch control method of the vehicle provided with the double clutch transmission may include determining, by the controller, whether a vehicle is travelling at the lowest shifting stage or the highest shifting stage and the pre-engagement of a proximate shifting stage is completed or not; storing a learned driveshaft clutch torque and a current clutch temperature and initiating a timer when it is determined that the learned driveshaft clutch torque is considered reliable by the controller learning the driveshaft clutch torque; determining, by the controller, a plurality of conditions including the passage of time to determine whether a touch point learning of the non-driveshaft clutch is necessary or not; and disengaging, by the controller, the proximate shifting stage of the non-driveshaft to neutral when it is determined that the touch point learning is necessary and performing the touch point learning of non-driveshaft.

A clutch control method of the vehicle provided with the double clutch transmission may include determining, by the controller, whether a vehicle is travelling at the lowest shifting stage or the highest shifting stage and the pre-engagement of a proximate shifting stage is completed or not; storing a learned driveshaft clutch torque and a current clutch temperature and initiating a timer when it is determined that the learned driveshaft clutch torque is considered reliable by the controller learning the driveshaft clutch torque; determining, by the controller, a plurality of conditions including the passage of time to determine whether a touch point learning of the non-driveshaft clutch is necessary or not; and disengaging, by the controller, the proximate shifting stage of the non-driveshaft to neutral when it is determined that the touch point learning is necessary and performing the touch point learning of non-driveshaft.

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.

Provided is a method of learning a touch point of a dual clutch transmission (DCT), and more particularly, to a DCT touch point learning method in which a touch point is learned based on a difference between a virtual input shaft speed and a clutch non-drive shaft input speed using a virtual input shaft reference speed calculated based on the speed of a traveling vehicle. In a traveling situation in which the touch point cannot be learned using the non-drive shaft according to the related art because the input shaft behavior of the non-drive shaft is rotationally synchronized with the input shaft behavior of the drive shaft by drag characteristics of the DCT, a virtual input shaft speed may be calculated, and the touch point of the clutch may be learned using the virtual input shaft speed.

A transmission combination includes a hydrostatic transmission and a mechanical transmission having a clutch and a control device for calibrating a grinding point of the clutch. A traction drive includes the transmission combination. A method includes calibrating the clutch.

The present disclosure provides a control method and a control system of a dual clutch transmission for a vehicle. The method includes: a pre-engagement-determining step of determining whether any one of gears has been pre-engaged, by means of a controller; a clutch-moving step of generating an oscillation signal to the release input shaft and increasing a clutch position value of the release input shaft; and a signal-determining step of determining whether the oscillation signal generated to the release input shaft is sensed at the engagement input shaft.

While a vehicle is traveling in a state where any one of gear positions of a mechanical stepped transmission unit is established, until an estimated input torque that is obtained from the equation of motion for an electrical differential unit changes, a hydraulic pressure of a non-engaged intended hydraulic friction engagement device is increased, and a pack end pressure is learned on the basis of the hydraulic pressure at that time. Therefore, irrespective of feedback control, or the like, over motor generators of the electrical differential unit, it is possible to appropriately learn the pack end pressure, so it is possible to appropriately execute hydraulic control over the hydraulic friction engagement devices, that is, engaging and releasing control, or the like, at the time of shifting, irrespective of individual differences of the portions, aging of friction materials, or the like.