A vehicle includes an engine, an electric machine, a torque converter and a controller. The torque converter includes an impeller and receives power from the engine and electric machine. The controller, in response to an absence of driver demanded torque and a difference between desired and estimated impeller speeds, adjusts a torque of the electric machine based on a difference between an estimated engine torque and a desired impeller torque in order to drive the impeller toward the desired impeller speed.

An adaptive feedforward control method for an electrified powertrain including a torque converter includes determining a desired input speed for a torque converter based on the set of operating parameters of the electrified powertrain, determining minimum and maximum torques for an impeller of the torque converter based on the set of operating parameters of the electrified powertrain, determining a raw feedforward torque for the torque converter impeller based on the desired input speed for the torque converter and a speed of a turbine of the torque converter, determining a final feedforward torque for the torque converter impeller based on the raw feedforward torque for the torque converter impeller and the minimum and maximum torques for the torque converter impeller, and controlling an electric motor of the electrified powertrain based on the final feedforward torque for the torque converter impeller.

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.