An oil pressure control device applied to an oil pressure device includes a calculation unit that estimates a delay of an actual oil pressure actually supplied from an oil pressure circuit to an friction engagement element of the oil pressure device with respect to an instruction pressure that instructs an oil pressure to be supplied from the oil pressure circuit to the friction engagement element, and calculates an estimated actual oil pressure obtained by taking the estimated delay of the actual oil pressure into consideration, a determination unit that determines whether a slip amount that occurs in the friction engagement element in an intermediate state between an engagement state and a disengagement state reaches a predetermined reference slip amount, and a setting unit that sets the estimated actual oil pressure as the instruction pressure when the determination unit determines that the slip amount reaches the reference slip amount.

Provided is a hydraulic oil control device having a shifting control unit configured to, in a case where, when upshifting is performed, a number of revolutions of an input shaft connected to a to-be-engaged clutch is higher than a number of revolutions of the engine, or a case where, when downshifting is performed, the number of revolutions of the input shaft is lower than the number of revolutions of the engine, supply the to-be-engaged clutch with a hydraulic oil having a pressure equal to or higher than a predetermined standby pressure, and then to supply the to-be-engaged clutch with the hydraulic oil having the standby pressure, and then configured to cause the to-be-engaged clutch to be engaged by supplying the to-be-engaged clutch with the hydraulic oil having a pressure higher than the standby pressure.

A control apparatus for a vehicle provided with a step-variable transmission including a one-way clutch to be placed in an engaged state to establish a predetermined one of gear positions of the step-variable transmission, and a coupling device disposed parallel with the one-way clutch, includes a control portion configured to control a shift-up action of the step-variable transmission from the above-indicated predetermined one gear position in which the coupling device is placed in its engaged state, the control portion controlling the shift-up action so as to delay a releasing action of the coupling device where a required torque of the vehicle prior to a moment of initiation of an inertia phase of the shift-up action is larger than a predetermined value, with respect to the releasing action where the required torque is not larger than the predetermined value.

A method for controlling a hydraulically actuated shift element of a vehicle transmission (G) includes determining a fill level of a pressure compensating cavity (2) associated with a pressure chamber (1) and controlling pressurizing of the pressure chamber (1) with hydraulic fluid based at least in part on the determined fill level of the pressure compensating cavity (2). The pressure chamber (1) is fillable with the hydraulic fluid by an electronically controlled hydraulic system in order to actuate the shift element.

The disclosure provides a control device for a vehicle, as an acceleration priority shift control that selects the shift stage set by the automatic transmission (TM) by preferentially using the information of acceleration of the vehicle (1), the traveling control part (120) calculates a maximum acceleration (Gmax) and a minimum acceleration (Gmin) of the vehicle (1) by using external information of the vehicle (1); calculates a target acceleration (Gt) by comparing the calculated maximum acceleration (Gmax) and minimum acceleration (Gmin) with a preset optimum acceleration (Gi); calculates a target shift stage (SHt) of the automatic transmission (TM) based on a current state of an engine (EG) in accordance with the calculated target acceleration (Gt); and calculates a standby pressure (Pm) for a clutch of the calculated target shift stage (SHt), and performs standby pressure control of the clutch with the calculated standby pressure (Pm).

An oil pressure control device applied to an oil pressure device includes a calculation unit that estimates a delay of an actual oil pressure actually supplied from an oil pressure circuit to an friction engagement element of the oil pressure device with respect to an instruction pressure that instructs an oil pressure to be supplied from the oil pressure circuit to the friction engagement element, and calculates an estimated actual oil pressure obtained by taking the estimated delay of the actual oil pressure into consideration, a determination unit that determines whether a slip amount that occurs in the friction engagement element in an intermediate state between an engagement state and a disengagement state reaches a predetermined reference slip amount, and a setting unit that sets the estimated actual oil pressure as the instruction pressure when the determination unit determines that the slip amount reaches the reference slip amount.

The present invention provides improved gear-changing quality of a motor vehicle having an automatic transmission, in which filling pressure adaptation processes are carried out by an electronic control device by predefined activation of an oil pump and selected hydraulic switching elements. A minimum time margin between the individual adaptation processes is predefined by the control device such that parallel adaptation processes are prevented.

A method of operating an automatic transmission of a motor vehicle, in which a hydraulic pump associated with a hydraulic system for the supply of pressure is driven by a drive motor. When the motor vehicle starts, a hydrodynamic starting element forms a driving connection between the drive motor and the automatic transmission. Hydraulic shifting elements (B1, B2, B3, C1, C2) are actuated for engaging gear steps. When the drive motor is started, a shifting element (B1, B2, B3, C1, C2) of the automatic transmission is engaged, and, during the engagement process of the shifting element (B1, B2, B3, C1, C2), a time of a rotational speed variation (n.sub.Ab, n.sub.Tu) of the automatic transmission is determined. With the help of the determined rotational speed variation (n.sub.Ab, n.sub.Tu), a time point is determined at which a pressure present in the hydraulic system reaches or exceeds a target pressure level.

A method for CVT low oil pressure input clutch fill compensation includesperforming a garage shift when a modeled fill pressure is equal to a commanded modeled fill pressure. Then the line pressure is checked to determine if it is less than the commanded fill pressure when performing the garage shift. If so, then the modeled fill pressure is set to the line pressure and the primary and secondary actual pulley pressures are read by sensing devices. Next, the primary and secondary commanded pulley pressures are checked to determine if they are greater than the modeled fill pressure. If so, then a first dPressure value for the flow rate model based on the lowest of the modeled fill pressure, the primary actual pulley pressure, or the secondary actual pulley pressure is determined and it is used to compensate the flow rate model.

In order to pre-stage a clutch piston in preparation for clutch engagement, a controller commands a high current to a Casting Integrated Direct Acting Solenoid (CIDAS) valve. This staging is performed in two distinct phases wherein the current is higher in the first phase than in the second phase. Staging the piston in this manner reduces the staging time and reduces the variability of the staging time. The duration of the first phase may be adjusted based on a number of parameters including, the length of a preceding engine off period, the number of clutch applications since the engine off period, a fluid temperature, and a length of time since a preceding engagement of the clutch.