Method and system for controlling running mode change for hybrid vehicle

摘要

A method and system for controlling a running mode change that prevent shock generated when releasing an engine clutch in changing from a running mode to another running mode. The method includes detecting, by a controller, a running mode change occurring in the hybrid vehicle and determining whether to change a state of the engine clutch from a lock-up state to an open state while the running mode change is being processed. The controller is further configured to slip-control the engine clutch to prevent torque occurring at a point in time when the engine clutch is changed to the open state from being transmitted to a driving shaft connected to the transmission, when the state of the engine clutch is determined to be changed from the lock-up state to the open state.

主权项

1. A method of controlling a running mode change for a vehicle which includes an engine clutch that controls power transmission between an engine and a motor, and a transmission clutch that connects the motor and an input shaft of a transmission, the method comprising:
detecting, by a controller, a running mode change of the vehicle; determining, by the controller, whether to change a state of the engine clutch from a lock-up state to an open state during the running mode change; slip-controlling, by the controller, the transmission clutch to prevent torque occurring when the engine clutch changes to the open state from being transmitted to a driving shaft connected to the transmission, when the state of the engine clutch changes from the lock-up state to the open state; operating, by the controller, the motor at a target speed to correspond to the running mode change; synchronizing, by the controller, a speed of the motor with an input speed of the transmission clutch by operating the motor; and controlling, by the controller, pressure supplied to the transmission clutch to equalize transmission torque of the transmission clutch and demand torque, wherein the running mode change when the state of the engine clutch changes from the lock-up state to the open state is a change from a hybrid electric vehicle (HEV) mode to a regenerative braking (RB) mode, wherein the transmission torque of the transmission clutch is calculated using equation:
transmission torque=(a friction coefficient of the transmission clutch)×(an effective radius of the transmission clutch)×(a delta RPM sign), and wherein the delta RPM sign is a plus sigh (+) or a minus sign (−).