METHOD OF LINE PRESSURE LEARNING FOR CONTINUOUSLY VARIABLE TRANSMISSION AND SYSTEM THEREOF

摘要

Disclose are a line pressure learning method and apparatus for a continuously variable transmission, which can accurately learn an actual line pressure when a line pressure sensor is not applied to minimize the difference between the actual line pressure and pulley pressure, thereby improving durability and fuel efficiency. According to the present invention, the line pressure learning method for a continuously variable transmission which comprises a driving pulley and a driven pulley and delivers power by connecting the pulleys using a belt comprises the steps of: entering line pressure learning mode when a shift lever selects a P or N gear stage; actuating a solenoid valve for line pressure control to the maximum to supply the maximum line pressure to the driven pulley, and measuring the pressure of the driven pulley corresponding to line pressure by using a driven pulley pressure sensor; detecting the deviation between the pressure of the driven pulley and target line pressure to compensate for line pressure control current; and storing the line pressure control current as a learning value when the pressure of the driven pulley converge on the target line pressure and the convergence is maintained for a predetermined time.