A hybrid vehicle includes a powertrain having a retarded diesel engine, an electric machine and energy storage system. The engine and motor are operatively coupled through one or more planetary gearsets and selective coupling paths in accordance with application and release of various torque transfer devices to a drivetrain via an output. Regenerative and retarded engine braking are coordinated to provide priority to energy return to an energy storage system in accordance with predetermined power flow limits. Power flow in excess of the limits are handled by increased engine retard braking contributions via engine speed increases.
A detection unit directly detects an operating force acting on a wheel. A computation unit respectively computes a current value of a regenerative braking force and a current value of a friction braking force based on the result of a detection by the detection unit. A setting unit sets a target value of the regenerative braking force and a target value of the friction braking force based on a required braking force. A control unit controls a regenerative braking device based on the current value of the regenerative braking force so that the regenerative braking force approaches to the target value and also controls a friction braking device based on the current value of the friction braking force so that the friction braking force approaches to the target value.
A method is disclosed for managing power in a hybrid electric vehicle powertrain having multiple components, including an engine, a motor, a generator and a high voltage battery. Power losses in the individual components are computed. An engine speed corresponding to a minimum value for the power losses is selected to achieve optimal total powertrain efficiency.
