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 shift control apparatus for a vehicle automatic transmission to be provided in a vehicle that includes a hydraulic transmission device having a lockup clutch, an engine, an input shaft connected to the engine through the hydraulic transmission device, and drive wheels. The shift control apparatus includes a shift-down control portion configured, when a shift-down operation is executed to establish a first gear position by releasing a second engagement device, during running of the vehicle in a driven state with a second gear position being established with engagement of the second engagement device, to increase a torque of the engine so as to increase an input rotational speed as a rotational speed of the input shaft through the lockup clutch that is placed in an engaged state, and to release the lockup clutch before the input rotational speed reaches a synchronous speed of the first gear position.

A method for preventing an incorrect learning of a clutch torque of a transmission of a vehicle may include a controller estimating an engine-based clutch torque estimated based on an engine torque; the controller estimating a wheel-based clutch torque estimated based on a driveshaft torsional torque; the controller determining a torque error, which is a difference between the engine-based clutch torque and the wheel-based clutch torque: the controller allowing a learning of the clutch torque when the torque error is equal to or less than a predetermined reference torque; and the controller prohibiting the learning of the clutch torque when the torque error is greater than the predetermined reference torque.

A shift control apparatus for a vehicle automatic transmission to be provided in a vehicle that includes a hydraulic transmission device having a lockup clutch, an engine, an input shaft connected to the engine through the hydraulic transmission device, and drive wheels. The shift control apparatus includes a shift-down control portion configured, when a shift-down operation is executed to establish a first gear position by releasing a second engagement device, during running of the vehicle in a driven state with a second gear position being established with engagement of the second engagement device, to increase a torque of the engine so as to increase an input rotational speed as a rotational speed of the input shaft through the lockup clutch that is placed in an engaged state, and to release the lockup clutch before the input rotational speed reaches a synchronous speed of the first gear position.

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.

A method and a system of learning a pressure applied to a brake of a countershaft may include determining, when a shift condition is satisfied, whether a shifting to be performed is a power off upshift; releasing a clutch mounted between a power source and the transmission when the shifting to be performed is the power off upshift; detecting a contact duration until a speed of an input shaft of the transmission is lowered by a predetermined speed by applying a target pressure stored in a memory to the brake of the countershaft when the release of the clutch is completed; comparing the contact duration with a predetermined duration; correcting, when the contact duration is greater than the predetermined duration, the target pressure according to a difference between the contact duration and the predetermined duration; and storing and updating the corrected target pressure in the memory to apply a subsequent power on upshift.

A method of controlling a dual clutch transmission, may include releasing a pressure of a non-driveshaft clutch and engaging a gear of a non-driveshaft; applying a first pressure to the non-driveshaft clutch and disengaging the gear of the non-driveshaft; determining a drag torque on the basis of a first rotation speed change rate of the non-driveshaft; releasing the first pressure and engaging the gear of the non-driveshaft; applying a second pressure to the non-driveshaft clutch and disengaging the gear of the non-driveshaft; determining a touch point torque on the basis of a second rotation speed change rate of the non-driveshaft; and adjusting a touch point of the non-driveshaft clutch on the basis of a net torque which is a difference between the touch point torque and the drag torque.

The present disclosure relates to a method for determining at least one shift parameter of a vehicle transmission (3), the vehicle transmission (3) comprising a first clutching device (8a) and a first speed ratio (9a); a second clutching device (8b) and a second speed ratio (9b); an input; and an output, wherein the input and the output of the transmission are connectable by the engaging first clutching device (8a) or the second clutching device (8b). The method comprises the steps: performing a shift by disengaging the first clutching device (8a) and/or engaging the second clutching device (8b), wherein the first clutching device (8a) stops transferring torque through the transmission at a first time point, wherein the second clutching device (8b) starts transferring torque through the transmission at a second time point, and determining the shift parameter at the first time point and/or at the second time point.

A method of controlling a dual clutch transmission, may include releasing a pressure of a non-driveshaft clutch and engaging a gear of a non-driveshaft; applying a first pressure to the non-driveshaft clutch and disengaging the gear of the non-driveshaft; determining a drag torque on the basis of a first rotation speed change rate of the non-driveshaft; releasing the first pressure and engaging the gear of the non-driveshaft; applying a second pressure to the non-driveshaft clutch and disengaging the gear of the non-driveshaft; determining a touch point torque on the basis of a second rotation speed change rate of the non-driveshaft; and adjusting a touch point of the non-driveshaft clutch on the basis of a net torque which is a difference between the touch point torque and the drag torque.