Disclosed is a method of controlling a damper clutch through learning. A controller determines whether a driving condition of a vehicle is a condition where a predetermined selected fluid pressure value is desired. When necessary learning conditions are satisfied, the controller applies a control current for realizing a relevant fluid pressure to the solenoid valve. The controller updates the control current of the solenoid valve to an appropriate value based on response of the damper clutch. Thereafter, the controller controls the solenoid valve based on the updated control current.

A controller and a control strategy for a hybrid electric vehicle having a traction motor between an engine and an automatic transmission include maintaining a bypass clutch of a torque converter in an engaged position and applying a motor torque from a traction motor to the torque converter such that slip of the torque converter does not otherwise reach zero while the bypass clutch is maintained in the engaged position.

A method of evaluating a thermal effect of torque converter clutch slip speed calibration settings on a torque converter includes estimating values of a plurality of vehicle operating parameters with a drive simulation model on a computer. The drive simulation model uses drive cycle inputs of a test drive cycle, and a slip speed calibration table to estimate values of the plurality of vehicle operating parameters over a pre-defined period of time for the test drive cycle. The temperature of each of a plurality of discrete regions of the torque converter are estimated with a temperature model on the computer. The temperature model uses the estimated values of the vehicle operating parameters to estimate the temperature of each discrete region of the torque converter at different times during the pre-defined period of time of the test drive cycle.

In a transmission with a lockup clutch, in a case where zero-slip control of the lockup clutch is not established (converged) within a predetermined time, a sweep increase of a lockup clutch hydraulic pressure starts at an increase rate smaller than a normal increase rate in a case where the zero-slip control is established within the predetermined time, the increase rate until the end of the sweep increase is set to be equal to or less than the normal increase rate, and in addition, a hydraulic pressure at the time of the end of the sweep increase is set to be equal to or greater than a hydraulic pressure in a case where the zero-slip control is established within the predetermined time. With such control, in a case where the zero-slip state is not brought, suppressing the occurrence of shock when complete engagement is carried out.

A method for operating a vehicle is disclosed. The vehicle has at least one torque transmission device which when rotating splashes in a fluid, at least two axles each having at least two wheels and at least one controllable coupling device adapted for selectively coupling or decoupling the torque transmission device with at least one of the wheels. The method includes the steps of: in an operating state in which no torque is requested by a driver of the vehicle, decoupling with the control device the torque transmission device and the at least one wheel when a driving speed of the vehicle is greater than or equal to a predetermined speed threshold value and coupling with the control device the torque transmission device and the at least one wheel for torque transmission when the driving speed is smaller than the predetermined speed threshold value.

Methods and systems are provided for inducing vehicle side slip. In one example, a method includes 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 control device controls a lockup clutch interposed between an engine and an automatic transmission mechanism of a vehicle. The control device includes a control part supplying hydraulic pressure to the lockup clutch and controlling differential pressure of the lockup clutch. The control part supplies the hydraulic pressure to the lockup clutch so that the differential pressure is lower than a reference differential pressure in a disengaged state of the lockup clutch. In a case of shifting the lockup clutch from the disengaged state to an engaged state, the control part supplies the hydraulic pressure to the lockup clutch so that the differential pressure increases as a filling ratio of an oil passage of the lockup clutch decreases. The reference differential pressure is a lower limit of the differential pressure that increases a slip ratio of the lockup clutch or reduces a slip amount of the lockup clutch.

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 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 torque convertor and direct drive unit arrangement and operating methods are provided herein. In one example, a prime mover may be configured to be coupled to a transmission via one of a torque convertor and a direct drive unit, the direct drive unit including a higher range clutch and a lower range clutch.