A control apparatus for an automatic transmission including a torque converter with a lock-up clutch capable of connecting the output shaft of an engine and the input shaft of the automatic transmission includes a state determination unit configured to determine, based on an operation signal from an ABS device, whether the ABS device of a vehicle is in a normally operating state or in a fail state, a rotation speed determination unit configured to determine whether the rotation speed of the input shaft is not less than a reference rotation speed, and an operation control unit configured to control engagement of the lock-up clutch based on the operation state of the ABS device and the result of comparison between the rotation speed of the input shaft and the reference rotation speed.

A method and a system for controlling a backlash of a powertrain included in a vehicle in connection with a gear shifting operation is presented. The method comprises: controlling, in connection with a first gear shifting operation, a clutch included in the powertrain to a slipping position, in which slipping position the clutch transfers a slipping torque that is less than a torque being transferred in a closed position for the clutch; analyzing a change of a rotational speed for an input shaft of a gearbox included in the powertrain; determining a position for the clutch, for which position the change of the rotational speed has a value corresponding to a backlash torque, the backlash torque having a predetermined value for eliminating the backlash; and utilizing the determined clutch position for controlling the clutch in connection with a second subsequent gear shifting operation.

A clutch actuator for a manual-shift motor vehicle transmission, includes a driver-operated clutch pedal or lever, a clutch linkage between a clutch of the motor vehicle and the pedal or lever, and a damper adapted to delay clutch engagement on a fast release of the clutch pedal or lever. The damper is effective to delay clutch engagement only within a limited range of a whole clutch engagement movement and is substantially ineffective outside the limited range and within the whole range of a clutch disengagement movement.

A method for controlling PTO clutch engagement includes determining a first change in clutch speed based on an inertial load of a PTO implement. The method also includes determining a second change in clutch speed based on a threshold amount of energy of a PTO clutch. The method further includes determining a third change in clutch speed between the first change in clutch speed and the second change in clutch speed. The method also includes adjusting a clutch current based on the third change in clutch speed.

A vehicle launch control method may include judging, by a controller, whether or not a vehicle starts to be launched, determining, by the controller, target clutch torque through a designated first determination method and controlling a clutch based on the determined target clutch torque, upon judging that the vehicle starts to be launched, and determining, by the controller, target clutch torque through a designated second determination method differing from the first determination method and controlling the clutch based on the determined target clutch torque, when an engine speed variation and engine speed jerk respectively satisfy designated variation conditions and jerk conditions during determination of the target clutch torque through the first determination method and control of the clutch based on the determined target clutch torque.

When a vehicle is switched from a two-wheel-drive mode to a four-wheel-drive mode during turning, rotation of a Rr dog clutch is synchronized by a synchro mechanism. Rotation of a Fr dog clutch is synchronized, by controlling coupling torque of a control coupling that transmits power to a rear wheel that provides an outer wheel during turning. Thus, rotation of the Fr dog clutch is also synchronized, so that shock at the time of engagement of the Fr dog clutch can be suppressed.

An agricultural vehicle includes an engine, a transmission driven by the engine, and a controller. The controller, in operation, adjusts a gear ratio of the transmission using an algorithm. The algorithm, in operation, performs the following steps: reduce a torque capacity of a first offgoing clutch of the transmission to a first torque target, reduce the torque capacity of the first offgoing clutch to a second torque target while adjusting the torque capacity of a first oncoming clutch of the transmission to a third torque target, such that the gear ratio of the transmission is modified in a first direction, and increase the torque capacity of the first oncoming clutch to a desired torque capacity.

A system includes an engine, a transmission driven by the engine, and a controller. The controller is configured to receive a speed input, receive feedback indicative of a load of the engine at a current engine speed, compare the load to a predetermined load threshold at the current engine speed, determine an expected engine speed based at least on the current engine speed, a current gear ratio, and an expected gear ratio, determine an estimated engine power at the expected engine speed and a current engine power at the current engine speed, and command a gear downshift when the load is greater than or equal to the predetermined load threshold and when the estimated engine power is greater than the current engine power.

A method of controlling launch of a vehicle, may include setting step in which a controller sets a basic target engine speed; a transient control step in which the controller controls a clutch torque based on the basic target engine speed; a transient state determining step in which the controller determines, whether a transition period of change of the engine speed elapsed; a first correction amount determination step in which the controller determines a correction amount; a correction applying step in which the controller adds the correction amount to the predetermined target engine speed and then determines a final target engine speed; an error determination step in which the controller determines the engine speed control error; and a feedback determination step in which the controller uses the engine speed control error and determines a feedback control amount for feedback-controlling a clutch actuator.

A method for maintaining an engine speed of an engine of a work vehicle includes sending a requested parameter indicative of the engine speed to an engine controller of the work vehicle. The method also includes receiving a measured parameter indicative of the engine speed. The method further includes determining whether the requested parameter is different from the measured parameter. The method also includes setting a controller-requested parameter indicative of the engine speed based at least in part on the requested parameter and the measured parameter. The method further includes sending the controller-requested parameter to the engine controller. The method accounts for speed and torque saturation in order to avoid windup in the controller.