A method for setting a shift point for shifting a transmission for a powered vehicle between a first gear ratio and a second gear ratio. The method includes determining input power data points based on real-time input torque data. The input torque data includes a maximum input torque. The method also includes calculating a gear step value based on the first gear ratio and second gear ratio. The method further includes determining a first power value and computing a second power value based on the gear step value. The first power value and second power value are compared to one another and adjustments are incrementally made in the first power value speed until the difference between first and second power values meets a threshold. The shift point is therefore based on the result of comparing the first power value and the second power value and the corresponding speed associated with the first power value.

A transmission calibration tool automatically generates a detailed gearbox model based on a user input transmission topology description. During transmission calibration, the tool accepts inputs from transmission speed and torque sensors and estimates component torques for each gear element and each shift element. Following a shift or other transmission event, the calibration tool plots the component torques as a function of time, permitting the calibration engineer to better understand what is occurring during the event, and thus reducing the time required for calibration. The calibration tool also adapts several transmission component models and outputs the adapted models to provide insight into actual transmission component behavior.

A vehicle control device including an electronically controlled throttle device and configured to control a vehicle for supplying a hydraulic pressure to a friction engaging element of a transmission on the basis of a throttle valve opening controls a start timing of a supply of the hydraulic pressure to the friction engaging element on the basis of an accelerator pedal opening and the throttle valve opening if a shift lever is changed from an advance position to a reverse position or from the reverse position to the advance position.

A control apparatus of an automatic transmission including a plurality of gear mechanisms, frictional elements, an oil pressure supply device which supplies an oil pressure for operating the frictional elements between an engaged state and a disengaged state and an oil pressure controller which controls an oil pressure for operating the plurality of frictional elements. The oil pressure controller determines a heat quantity absorbed by the plurality of frictional elements when the frictional elements are switched between the engaged state and the disengaged state, and changes an operation state before the frictional elements proceed to the engaged state or the disengaged state, in accordance with whether the frictional elements have absorbed a predetermined heat quantity.

The present invention provides a control unit. When the control unit performs shifting from a state in which a first shift speed is established by supplying engagement pressures to both hydraulic oil chambers and engaging a predetermined engagement element to a second shift speed by switching engagement and disengagement states of engagement elements other than the predetermined engagement element (Step S1), the control unit reduces the supply of the engagement pressure to one of the two hydraulic oil chambers to a level lower than that in the state in which the first shift speed is established (Step S3).

An automatic transmission for a vehicle includes: an automatic transmission mechanism including friction engaging elements which change a power transmission path between an input shaft and an output shaft, an engaging oil pressure control unit which controls an engaging oil pressure that engages a first friction engaging element, and a releasing oil pressure control unit which controls a releasing oil pressure that releases a second friction engaging element, so as to achieve upshifting to a predetermined gear shift stage; and a control device including an engaging oil pressure computing unit which calculates and outputs the engaging oil pressure, a releasing oil pressure computing unit which calculates and outputs the releasing oil pressure, a pulled state determination unit which determines whether or not the vehicle is in a pulled state, and a travel load increase calculation unit which calculates an increase in travel load of the vehicle.

A control system and method for controlling a multiple gear ratio automatic transmission in a powertrain for an automatic transmission having pressure activated fiction torque elements to effect gear ratio upshifts. The friction torque elements are synchronously engaged and released during a torque phase of an upshift event as torque from a torque source is increased while allowing the off-going friction elements to slip, followed by an inertia phase during which torque from a torque source is modulated. A perceptible transmission output torque reduction during an upshift is avoided. Measured torque values are used during a torque phase of the upshift to correct an estimated oncoming friction element target torque so that transient torque disturbances at an oncoming clutch are avoided and torque transients at the output shaft are reduced.

A method for rocking a vehicle free. The vehicle comprises a drive aggregate (2), a transmission (4), shifting elements (10), and a starting element (5). The rocking free process is carried out as a function of actuation of an accelerator pedal (11) by the driver or a torque delivered by the drive aggregate (2) as a function of the actuation of the accelerator pedal. The shifting element (10) is controlled such that reduced actuation of the accelerator pedal or reduced torque delivered by the drive aggregate (2), reduces a control pressure of the shifting element (10) of the transmission (4) down to a filling pressure or a pressure that corresponds to the filling pressure, and increased actuation of the accelerator pedal or increased torque delivered by the drive aggregate (2), increases the control pressure of the shifting element (10) and the shifting element is operated in a slipping mode.

A select control device for an automatic transmission includes a select lever and a controller. The select lever is configured to select a range position in response to a select operation by a driver. The controller is configured to, when a first select operation from a first travel range position to a non-travel range position is performed, perform pressure release control that decreases at a prescribed descending gradient an engagement capacity of a starting clutch that is engaged in the first travel range position. The controller has a select hydraulic pressure control unit configured to continue the pressure release control during a second select operation from a second travel range position that is different from the first travel range position to the non-travel range position after the first select operation.

A shift control device for an automatic transmission includes: an engagement control unit that controls an engagement hydraulic pressure supplied to an engagement hydraulic chamber of an engagement side friction element; a hydraulic pressure detecting unit that detects the engagement hydraulic pressure; a reference setting unit that calculates a predicted value of the engagement hydraulic pressure during shifting, based on a rising characteristic of the engagement hydraulic pressure from when supply of the engagement hydraulic pressure is started to when engagement of the engagement side friction element is started, and sets the predicted value as a reference hydraulic pressure; and an engagement start detecting unit that detects an engagement start time point of the engagement side friction element, based on a difference between the hydraulic pressure detected by the hydraulic pressure detecting unit during the shifting and the reference hydraulic pressure.