A friction engagement element control system is provided, which includes a friction engagement element including friction plates, and an actuation system configured to engage an input-side friction plate with an output-side friction plate with a pushing force, the friction plates having a negative slope characteristic in which a friction coefficient thereof decreases as a rotational difference between the friction plates increases, a rotational difference sensor of the friction engagement element, a separator configured to divide a variation in the detected rotational difference into a high-frequency component that is a vibration component and other low-frequency components, and a controller configured to control a pushing force only for the vibration component of the rotational difference so that the negative slope characteristic becomes a positive slope characteristic in which a frictional force of the friction engagement element decreases as the rotational difference decreases, when engaging the friction engagement element.

The disclosure is concerned with control system and control method, for a vehicle including a driving power source, drive wheels, a first clutch, and a second clutch. An electronic control unit, which is included in the control system, places the first clutch in a half-engaged state with a predetermined clutch torque capacity, when the vehicle is started, performs start control in a first mode using the second clutch, by gradually increasing a clutch torque capacity of the second clutch from a released state, and switches the start control from the first mode using the second clutch to a second mode using the first clutch, when the increased clutch torque capacity of the second clutch reaches the clutch torque capacity of the first clutch.

Torque reduction control is executed for temporarily reducing a torque capacity of a reaction engagement device during a transition of a shift. The reaction engagement device is maintained in an engaged state from before the shift to after the shift such that a predetermined rotating element in an automatic transmission bears a reaction caused by progress of the shift resulting from a change of an engaging-side engagement device into an engaged state. Therefore, without delaying a change of the engaging-side engagement device into the engaged state, transmission of torque that is generated as a result of rattling during a transition of a shift is reduced. Thus, in shift control over the automatic transmission, shock at the time of rattling is reduced while a stop of a shift due to a delay in change of the engaging-side engagement device into the engaged state is prevented.

An automatic transmission device for a vehicle driven by transmitting a torque of an engine to driving wheels includes a clutch provided in a torque transmission system extending from the engine to the driving wheels, a transmission located between the clutch and the driving wheels in the torque transmission system, and a transmission controller. The transmission controller is configured or programmed to perform a torque feedback-control to bring the clutch into a sliding state in response to issue of a shift command and feedback-control a transmission torque to a target torque, disengage the clutch after the torque feedback-control, change a shift stage of the transmission according to the shift command after disengaging the clutch, and engage the clutch after changing the shift stage.

An apparatus for fixing a sticking damper clutch may include: a transmission controller configured to determine whether a damper clutch sticks, using engine controller information received from an engine controller and damper clutch status information of the damper clutch; and a hydraulic pressure controller configured to fix the sticking damper clutch according to the determination result of the transmission controller.

Torque reduction control is executed for temporarily reducing a torque capacity of a reaction engagement device during a transition of a shift. The reaction engagement device is maintained in an engaged state from before the shift to after the shift such that a predetermined rotating element in an automatic transmission bears a reaction caused by progress of the shift resulting from a change of an engaging-side engagement device into an engaged state. Therefore, without delaying a change of the engaging-side engagement device into the engaged state, transmission of torque that is generated as a result of rattling during a transition of a shift is reduced. Thus, in shift control over the automatic transmission, shock at the time of rattling is reduced while a stop of a shift due to a delay in change of the engaging-side engagement device into the engaged state is prevented.

A control device of an automatic transmission controls an automatic transmission 1 comprising a transmission mechanism 3 including a plurality of engagement elements, and a hydraulic oil supply device 4 supplying hydraulic oil to the transmission mechanism The control device of the automatic transmission comprises an engagement element control part 41 configured to use the hydraulic oil supply device to make the plurality of engagement elements change between an engaged state and a disengaged state; and a deceleration degree calculating part 42 configured to calculate a target deceleration degree of a vehicle in which the automatic transmission is provided. The engagement element control part is configured to make the engagement element in the disengaged state engage so that the vehicle decelerates if the target deceleration degree is equal to or more than a predetermined value when an increase in temperature of hydraulic oil in the automatic transmission is demanded.

In a speed change apparatus for a vehicle, a controller stores as a clutch-disengaging shift spindle angle 1 a position at which a clutch is disengaged when a shift spindle is rotated in a first direction. The controller controls the shift spindle by a first step W1 of rotating the shift spindle in the first direction until a disengaging-side target angle Ta1 is reached; a second step W2 of returning the shift spindle in a second direction opposite to the first direction; and a third step W3 of rotating the shift spindle in the first direction up to the clutch-disengaging shift spindle angle 1 and thereafter rotating the shift spindle in the second direction to return the shift spindle, upon detection of an output from a drum angle sensor, the output corresponding to shallow engagement of dog teeth.

A vehicle includes a transmission and a controller. The transmission has clutches that are configured to establish multiple speed ratios, including a first clutch. The first clutch has a measured drag torque distribution. The measured drag torque distribution has a median and a standard deviation. The controller is programmed to increase a pressure at a rate to engage the first clutch and to increase the rate in response to a measured first clutch torque exceeding the median by a predetermined multiple of the standard deviation.

A method for manufacturing a pole tube having two magnetic pole tube components and having one nonmagnetic ring, which is situated axially between the pole tube components, for an electromagnet, in particular for a solenoid valve of an automatic transmission in a motor vehicle, including the following: concentric configuration and/or centering of the pole tube components and of the ring, in particular on a centering pin; form-fitting connection, in particular by extrusion coating and/or casting an exterior lateral surface of the pole tube components and of the ring.