A work vehicle includes an engine, a drive wheel, a power transmission mechanism configured to transmit a driving power of the engine to the drive wheel, and a control unit configured to control the power transmission mechanism. The power transmission mechanism has a torque converter including a first clutch, and a second clutch coupled to the torque converter. The control unit controls an oil pressure supplied to the first clutch to a predetermined oil pressure when the second clutch is partially engaged.

Disclosed is a method for operating a multi-gear vehicle transmission having a plurality of shifting elements (A, B, C, D, E) for engaging the gears of the vehicle transmission, where, in a neutral gear an input (AN) and an output (AB) of the vehicle transmission are decoupled from one another, and where, in a driving gear the input (AN) and the output (AB) of the vehicle transmission are coupled to one another in order to propel the vehicle, by closing at least one shifting element (B). When the neutral gear is engaged, at least an actuation condition of a vehicle brake (11) and a transmission condition with elevated drag losses are detected, where, when the neutral gear is engaged, the shifting element (B) for the driving gear is vented if it is recognized that the vehicle brake (11) has been released and the transmission condition with elevated drag losses pertains.

A temperature estimation device for friction engaging elements including an execution device and a storage device is provided. The storage device stores mapping data that defines mapping. The mapping includes, as an input variable, a heat amount variable that is a variable indicating an amount of heat generated by the friction engaging elements during the shifting of the transmission and a shifting variable indicating the friction engaging elements to be engaged at the time of the shifting of the transmission, and, as an output variable, the temperature. The execution device executes an acquisition process of acquiring a value of the input variable and a calculation process of inputting the value of the input variable acquired by the acquisition process into the mapping to calculate a value of the output variable.

According to one embodiment, a vehicle includes a transmission, a brake pedal, and a controller. The controller is programmed to, in response to an upshift of the transmission, a driver-demanded torque being zero, and the brake pedal being released, command a first pressure, that is greater than zero, to an oncoming shift element associated with the upshift such that the oncoming shift element has a torque capacity of zero, in response to the brake pedal being applied during the upshift of the transmission, command a second, larger pressure to the oncoming shift element to increase the torque capacity to a non-zero value, and, in response to expiration of a threshold time from the brake pedal being applied, command a series of sequentially ramping pressures to the oncoming shift element to further increase the torque capacity and lock the oncoming shift element.

A vehicle control apparatus for controlling a control-subject component provided in a vehicle, by using a learning value of a control parameter which is obtained by a learning operation. The control apparatus includes an obtaining portion for obtaining information related to converged values of learning values of control parameters in a plurality of vehicles provided with respective control-subject components which are the same in type as the control-subject component provided in the vehicle, and a variation determination portion for determining whether a degree of variation among the converged values in the respective vehicles is smaller than a threshold value. The vehicle control apparatus causes the learning value to be converged by a smaller number of times of execution of the learning operation when the degree of the variation is smaller than the threshold value, than when the degree of the variation is not smaller than the threshold value.

A temperature estimation device for friction engaging elements including an execution device and a storage device is provided. The storage device stores mapping data that defines mapping. The mapping includes, as an input variable, a heat amount variable that is a variable indicating an amount of heat generated by the friction engaging elements during the shifting of the transmission and a shifting variable indicating the friction engaging elements to be engaged at the time of the shifting of the transmission, and, as an output variable, the temperature. The execution device executes an acquisition process of acquiring a value of the input variable and a calculation process of inputting the value of the input variable acquired by the acquisition process into the mapping to calculate a value of the output variable.

A work vehicle includes an engine, a drive wheel, a power transmission mechanism configured to transmit a driving power of the engine to the drive wheel, and a control unit configured to control the power transmission mechanism. The power transmission mechanism has a torque converter including a first clutch, and a second clutch coupled to the torque converter. The control unit controls an oil pressure supplied to the first clutch to a predetermined oil pressure when the second clutch is partially engaged.

A transmission control device is used in an automatic transmission device including a transmission gear having friction coupling portions that are changed between a coupled state and an uncoupled state, and configuring transmission stages corresponding to a combination of the coupled state and the uncoupled state, and a hydraulic control device. The device includes: a determination unit determining a change in the transmission stage; and an output unit setting a target value of the hydraulic pressure, and outputting the target value to the hydraulic control device. In a case where one transmission stage is changed to another, the output unit increases the target value to a first value for a first friction coupling portion in the uncoupled state in the one transmission stage, thereafter, to a second value smaller than the first value and maintaining the uncoupled state, and thereafter, to a third value greater than the second value.

A vehicle control apparatus for controlling a control-subject component provided in a vehicle, by using a learning value of a control parameter which is obtained by a learning operation. The control apparatus includes an obtaining portion for obtaining information related to converged values of learning values of control parameters in a plurality of vehicles provided with respective control-subject components which are the same in type as the control-subject component provided in the vehicle, and a variation determination portion for determining whether a degree of variation among the converged values in the respective vehicles is smaller than a threshold value. The vehicle control apparatus causes the learning value to be converged by a smaller number of times of execution of the learning operation when the degree of the variation is smaller than the threshold value, than when the degree of the variation is not smaller than the threshold value.

A vehicle control apparatus includes a learning control portion configured to execute a learning control operation, and to limit a learning value obtained through the learning control operation, by a guard value, and an update control portion configured to obtain a new guard value from an external device, and to update the guard value to the new guard value. The update control portion limits the learning value by the new guard value, prior to execution of the learning control operation, such that the learning value is rewritten, by the update control portion, to a value within a new guard-value range defined by the new guard value in a case in which the learning value is deviated from the new guard-value range, and such that the learning value is kept unchanged by the update control portion in a case in which the learning value is within the new guard-value range.