A drivability target engine speed is set based on a shift stage based on an accelerator opening level and a vehicle speed and the vehicle speed, and a base driving force is set based on an accelerator required driving force and the drivability target engine speed. When an elapsed time after an accelerator depression amount increases is less than a threshold value, a correction driving force is set based on an increase in accelerator depression amount and an engine, a first motor, and a second motor are controlled such that an effective driving force obtained by adding the correction driving force to the base driving force is output to a drive shaft for a hybrid vehicle to travel.

A shift control system that reduces drop in driving force and shocks during execution of clutch-to-clutch upshifting is provided. The control system is configured to reduce a torque transmitting capacity of a first clutch at a predetermined rate while increasing a torque transmitting capacity of a second clutch with a reduction in the torque transmitting capacity of the first clutch during execution of the upshifting, to set a target speed of the engine to a level determined by adding a predetermined speed to a synchronous engine speed corresponding to a low speed stage, during a torque phase in which the torque transmitting capacity of the first clutch is being reduced and the torque transmitting capacity of the second clutch is being increased, and to execute a feedback control of an engine torque in such a manner as to maintain the engine speed to the target speed based on a difference between the target speed and an actual engine speed.

In a method for controlling a vehicle with a drive system comprising an output shaft in a combustion engine, a planetary gear and a first and second electrical machine connected to the planetary gear, the turning off of the combustion engine is achieved when the vehicle is driven with the combustion engine running, and a transition to operation of the vehicle with the electrical machines is achieved by ensuring that the second electrical machine's rotor is connected with the combustion engine's output shaft, that injection of fuel into the combustion engine is interrupted and that the second electrical machines rotational speed is controlled towards and until a standstill, whereupon the combustion engine's output shaft is disconnected from the second electrical machine and the planetary gear.

The present disclosure provides a shift control method for a hybrid electric vehicle including: controlling a speed of a vehicle driving source; simultaneously controlling a release element and a connection element in a transmission based on a rotation acceleration of a transmission output shaft when shifting by a power-on down shift.

In a method for controlling a vehicle with a drive system comprising a power unit configuration adapted to provide power for the vehicle's operation, and further comprising a planetary gear and a first and second electrical machine, connected to components in the planetary gear via their rotors, a locking means is moved from a release position, in which the planetary gear's components are free to rotate independently of each other, to a locked position, in which two of the planetary gear's components are locked together, so that the three components in the planetary gear rotate with the same speed. The power unit configuration is controlled in order to achieve a synchronous, or substantially synchronous, rotational speed between the input and output shaft of the planetary gear, and the locking means are then moved to the locked position.

A propulsion system, control system, and method are provided for optimizing fuel economy, which use model predictive control systems to generate first and second predicted actual axle torques and first and second predicted actual fuel consumption rates based on first and second sets of possible command values, respectively. The sets of possible command values include commanded engine output torques and commanded transmission ratios. First and second costs are determined for the first and second sets of possible command values, respectively, based on a first predetermined weighting value, a second predetermined weighting value, the first and second predicted actual axle torques, respectively, the first and second predicted actual fuel consumption rates, respectively, an axle torque requested, an engine output torque requested, a transmission ratio requested, and a fuel consumption rate requested. One of the first and second sets of possible command values is selected and set based on the lower cost.

A computer for, e.g., a mass market passenger vehicle operable by a virtual driver in autonomous and/or semi-autonomous mode, is programmed to determine that a current vehicle braking capacity exceeds each of a first braking target and a mitigation threshold at a current vehicle speed. The computer is further programmed to compare the current vehicle speed to an engine breaking threshold and generate a transmission control message providing data to operate a vehicle transmission. Where the current vehicle speed is above the engine braking threshold, the transmission control message provides data to operate the vehicle transmission to inhibit transfer of an input torque through the vehicle transmission. Additionally, where the current vehicle speed is below a wheel lock threshold, the transmission control message further provides data to operate the vehicle transmission to inhibit rotation of an output shaft of the vehicle transmission.

A device is disclosed that performs highly accurate control in a low-torque region and improves the response of the hydraulic system, taking advantage of hydraulic sealed-type hydraulic control devices. The hydraulic sealed-type hydraulic control device includes: a first characteristic (sealed pressurization) obtained by closing an on-off valve and driving an oil pump; a second characteristic (sealed depressurization) obtained by disabling drive of the oil pump and opening the on-off valve; and a third characteristic (flow-rate control) obtained by opening the on-off valve and driving the oil pump. In a low-torque region, the device performs control according to the third characteristic. In a high-torque region, the device performs control according to the second characteristic. In the process of depressurization, the device performs control according to the second characteristic. Moreover, the device performs control to increase commanded hydraulic pressure in immediate response to an accelerator's change amount larger than a predetermined value.

A gearbox includes an input shaft and an output shaft; a first epicyclic gear connected to the input shaft; a second epicyclic gear connected to the first epicyclic gear; a first electrical machine connected to the first epicyclic gear; a second electrical machine connected to the second epicyclic gear; a first gear pair arranged between the first epicyclic gear and the output shaft; and a second gear pair arranged between the second epicyclic gear and the output shaft; a first planet gear carrier in the first epicyclic gear connected to a second sun gear in the second epicyclic gear; a first sun gear in the first epicyclic gear connected to a first main shaft; and a second planet gear carrier in the second epicyclic gear is connected to a second main shaft.

A drivetrain system includes a controller that is programmed to, in a presence of a request for increased drivetrain torque that results in reversal of drivetrain torque direction, command an increase in drivetrain torque at a reduced rate while a value that is based on drivetrain speed difference remains within a predetermined range absent a braking torque request exceeding a threshold. The controller is further programmed to command the increase at an accelerated rate upon the braking torque request exceeding the threshold.