A driving force control method is provided for engine clutch slipping of a TMED HEV that includes an engine 10 and a second motor 50, a first motor 30 disposed at a transmission side, an engine clutch 20 interposed between the engine 10 and the first motor 30, and a multi-clutch transmission 35 connected with an output terminal of the first motor 30. The method includes verifying whether a control for maintaining a target speed of the engine is achieved by an engine feedback control or by a second motor torque feedback control and applying clutch pressure for the clutch slipping with hydraulic pressure. When the clutch pressure is applied clutch slipping transmission torque is estimated. Torque of the engine clutch is equivalent to the pressure as a load. Second motor dischargeable limit torque, second motor assist torque, and engine torque are calculated to then execute a slip control.

A DCT shifting control method of a vehicle includes: a temporary engaging step that engages an N-3 stage gear having a gear ratio larger than an N stage gear that is a currently engaged gear; a first torque switching step that starts to slip a first clutch engaged with the N-3 stage gear and disengages a second clutch engaged with the N stage gear that is the currently engaged gear; a synchronization speed adjusting step that synchronizes a speed of a power source of a vehicle with a desired input shaft speed by controlling the power source of the vehicle, disengages the N stage gear, and engages the N-2 stage gear that is the desired gear, with the slip of the first clutch maintained; and a second torque switching step that finishes shifting by disengaging the first clutch and engaging the second clutch.

A method for learning engine clutch delivery torque of a hybrid vehicle includes: determining, by a controller, whether power transference of a transmission transmitting output from an engine of the vehicle and a motor of the vehicle is interrupted; controlling, by the controller, a speed of the motor to be maintained at a first speed when the power transference of the transmission is interrupted; calculating, by the controller, a first delivery torque of an engine clutch that connects the engine with the motor or disconnects the engine from the motor, based on the first speed and a second speed of the motor which is generated after the engine clutch is engaged; controlling, by the controller, the speed of the motor to be maintained at the second speed by releasing the engine clutch after the first delivery torque is calculated; and calculating, by the controller, a second delivery torque of the engine clutch based on the second speed and a third speed of the motor which is generated after the engine clutch is engaged.

A method for controlling torque transfer of a force-fitting shift element includes controlling a closing pressure at least temporarily upon presence of a closing request for the force-fitting shift element and when a prevailing system pressure of the hydraulic circuit is above a threshold value for the system pressure. The closing pressure is controlled in a manner that is different than upon the presence of the closing request for the force-fitting shift element and when the prevailing system pressure is below the threshold value for the system pressure.

A DCT shifting control method of a vehicle includes: a temporary engaging step that engages an N-3 stage gear having a gear ratio larger than an N stage gear that is a currently engaged gear; a first torque switching step that starts to slip a first clutch engaged with the N-3 stage gear and disengages a second clutch engaged with the N stage gear that is the currently engaged gear; a synchronization speed adjusting step that synchronizes a speed of a power source of a vehicle with a desired input shaft speed by controlling the power source of the vehicle, disengages the N stage gear, and engages the N-2 stage gear that is the desired gear, with the slip of the first clutch maintained; and a second torque switching step that finishes shifting by disengaging the first clutch and engaging the second clutch.

A method for learning engine clutch delivery torque of a hybrid vehicle includes: determining, by a controller, whether power transference of a transmission transmitting output from an engine of the vehicle and a motor of the vehicle is interrupted; controlling, by the controller, a speed of the motor to be maintained at a first speed when the power transference of the transmission is interrupted; calculating, by the controller, a first delivery torque of an engine clutch that connects the engine with the motor or disconnects the engine from the motor, based on the first speed and a second speed of the motor which is generated after the engine clutch is engaged; controlling, by the controller, the speed of the motor to be maintained at the second speed by releasing the engine clutch after the first delivery torque is calculated; and calculating, by the controller, a second delivery torque of the engine clutch based on the second speed and a third speed of the motor which is generated after the engine clutch is engaged.

A method for calibrating the feedback gains of an LQI controller implemented in an electronic control unit operatively connected for controlling operation of a physical electric or electro-mechanical device of a dynamic physical system, in particular a vehicle powertrain, wherein the method of calibrating the LQI controller includes: obtaining values of various physical parameters of the dynamic physical system; inserting the obtained values of the physical parameters into predetermined equations for calculating numerical values of the individual terms of a P matrix, wherein the P matrix is the solution to the Algebraic Riccati equation, and wherein said equations include the physical parameters of the system; and calculating new feedback gains for the LQI controller based on the matrix equation

[00001]$K=r^{-1}{B}_{\mathrm{aug}}^{T}P,$

based on an arbitrarily chosen positive value of r, wherein the terms of the K matrix corresponds to the feedback gains.

When a first traveling mode in which a driving wheel is driven by power generated by an electric motor is changed to a second traveling mode in which the driving wheel is driven by at least power generated by an engine, processing circuitry of a control device of a hybrid vehicle according to one aspect executes rotational frequency synchronization control of controlling the engine such that a rotational frequency of a transmission shaft which corresponds to rotation of the engine synchronizes with a rotational frequency of the transmission shaft which corresponds to rotation of the electric motor. During execution of the rotational frequency synchronization control, the processing circuitry controls a clutch such that a degree of engagement of the clutch which corresponds to a degree of power transmission between the engine and the transmission shaft increases.