A method for operating a drive-train of a motor vehicle. The drive-train having a transmission connected between a drive aggregate and a drive output. A hydrodynamic starting element is connected between the drive aggregate and transmission. The starting element includes a converter and converter lock-up clutch. A Power Take-Off (PTO) can be coupled to the drive aggregate on the drive aggregate side to take up drive torque delivered by the drive aggregate. In order to determine the torque taken up by the PTO, the lock-up clutch is operated in a rotational-speed-regulated manner at least when the PTO is coupled to the drive aggregate in order to set a defined target slip at the lock-up clutch. As a function of the actuation pressure of the lock-up clutch required for setting the target slip when the PTO is coupled, the torque taken up by the PTO is determined.

A continuously variable transmission (2) has a torque convertor (3) having a lock-up clutch (30) and a continuously variable transmission mechanism (5). A control unit (10) has a shift control unit (10C) configured to be able to perform a pseudo stepwise up-shift control that varies a transmission ratio of the continuously variable transmission mechanism (5) stepwise, a lock-up control unit (10A) configured to control an engagement state of the lock-up clutch (30), and a torque control command unit (10D) configured to perform a torque-down control of a driving source (1). When the engagement control of the lock-up clutch (30) and the pseudo stepwise up-shift control are performed at the same time, the torque control command unit (10D) configured to perform the torque-down control with a greater torque reduction mount.

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.

Methods and systems are provided for inducing vehicle side slip. In one example, a method comprises opening a sole driveline disconnect clutch positioned between an engine and an electric machine upstream of a transmission, and closing the sole driveline disconnect clutch within a predetermined amount of time after opening the sole driveline disconnect without shifting gears of the transmission. In this way, vehicle drift may be reliable initiated in a hybrid electric vehicle with an automatic transmission, without shifting gears of the transmission.

A method for operating a vehicle drive train (1) includes, during a downshift, disengaging at least one shift element (A through F) from a power flow of the transmission (5), guiding a power transmission capacity of a torque converter lockup clutch (4) to a level at which the torque converter lockup clutch (4) is in a non-slip operating condition during a positive engine override when a rotational speed of a prime mover (2) is guided towards a synchronous speed of a demanded desired ratio, and guiding the power transmission capacity of the torque converter lockup clutch (4)no later than a point in time of the downshift at which the rotational speed of the prime mover (2) is equal to the synchronous speed of the desired ratioto a level at which the torque converter lockup clutch (4) is transferred into a continuous slip operation due to torque.

A system for monitoring the components of a skid module comprising a load driven by a motor associated with an automatic transmission using lockup technology includes a smart box associated with the skid module. Exemplary loads include mud pumps and generators. A plurality of sensors are associated with skid components and electrically associated with the smart box. The smart box uses at least some of said plurality of sensors to determine if the lockup technology is working properly and generates a warning when a lockup failure is detected. The skid module status is reported to at least one of a local display device or a remote display device in communication with the smart device over a network.

A control system to control slip of a torque converter clutch includes a clutch plant model configured to predict a value of a parameter that relates to torque converter clutch slip as a function of clutch plant model inputs comprising commanded clutch pressure and of torque from the torque generative device. The control system also includes a model predictive controller configured to receive signals that allow determination of a desired value of the parameter that relates to torque converter clutch slip and a predicted value of the parameter that relates to torque converter clutch slip, receive a signal representing reported torque of the torque generative device, identify an optimal commanded clutch pressure value that will result in an optimal value of an objective function based on the clutch plant model, and provide a command signal to an actuator effective to control commanded clutch pressure to the torque converter clutch.

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.

A lockup disengagement control device for an automatic transmission including a torque converter including a lockup clutch, and a lockup control section, the lockup disengagement control device includes: when a brake is operated from a brake OFF to a brake ON during a coast traveling in an engagement state of the lockup clutch, the lockup control section being configured to sense an initial deceleration by the brake ON operation, and to set a lockup release vehicle speed to be higher as an absolute value of the initial deceleration is greater, and when a vehicle speed is sensed to be equal to or smaller than the set lockup release vehicle speed in a middle of a brake deceleration scene by the brake ON operation, the lockup control section being configured to disengage the lockup clutch.

A vehicle lock-up clutch control method is performed in which an output of an engine is transmitted to an automatic transmission via a torque converter having a lock-up clutch. The method includes controlling a transmission torque capacity of the lock-up clutch such that a slip rotation speed of the lock-up clutch becomes zero after the lockup clutch is brought into a non-engaged state immediately after starting an accelerator operation, and when the accelerator operation is carried out during a fuel cut of the engine or in a state in which a road load and a driving force of the vehicle are balanced, and after completion of a downshift when the automatic transmission is downshifted while executing a slip control of the lock-up clutch from the non-engaged state to an engaged state during the accelerator operation.