| 摘要 |
PURPOSE: A fail safe control device for hybrid vehicles is provided to diagnose shifting errors in shifting from EVT2 mode to EVT1 mode, to sense whether the shifting error of the EVT1 is due to a foreign substance that flowed into a fluid operating a friction element, or due to a functional disorder of a solenoid valve, and to prevent damage to the friction element comprised of a transmission by operating a fail safe control. CONSTITUTION: A fail safe control device for hybrid vehicles comprises: an engine and first and second motors which are a power source; a planetary gear comprising a first carrier connected to a second brake by the engine and a first clutch, a first sun gear connected to a first motor and the first brake, a second sun gear connected to an output shaft, a first ring gear connected to the second sun gear, a second sun gear connected to the engine by a second motor and a second clutch, and a second ring gear connected to a second brake; a hybrid controller for controlling the operation of the first and second motors; and a transmission controller for determining occurrence of a shifting error of the EVT1 mode by analyzing the velocity gradient and engine speed of the second ring gear while shifting the EVT2 mode to the EVT1 mode. A fail safe control method for hybrid vehicles comprises the following steps: determining occurrence of mode shifting from the EVT2 mode to the EVT1 mode while driving; determining whether a shifting error occurs by analyzing the engine speed and velocity gradient of the second ring gear, the velocity of the second ring gear and torque of the second motor during the process of shifting when the mode shifting occurs; and controlling the first and second motors within the speed limit by requesting a torque limit from the hybrid controller, and canceling the fluid pressure being supplied to the second brake when the shifting error occurs. [Reference numerals] (AA) Start; (BB,DD,FF,HH,JJ) Yes; (CC,EE,GG,II) No; (KK) End; (S101) Detect the state of a first motor and a second motor; (S102) Normal?; (S104) Detect the a second motor torque; (S105) Second motor torque < 0 ?; (S106) Determine the satisfaction of diagnosis conditions; (S107) R2 velocity, R2 velocity gradient, engine velocity detection; (S108) EVT1 mode conversion error?; (S109) Time counter; (S110) Is a preset time elapsed?; (S111) Determine the introduction of foreign materials or the abnormality of solenoid operation; (S112) Release hydraulic pressure and enable a warning lamp to blink; (S113) Request torque limitation; (S114) Control the first motor and the second motor within a limit speed; (S115) Enable the warning lamp to blink |
