BELT-BASED, CONTINUOUSLY-VARIABLE TRANSMISSION CONTROL DEVICE AND CONTROL METHOD

摘要

Provided are a belt-based, continuously-variable transmission control device and a control method with which control stability of secondary hydraulic pressure can be improved while assuring estimation accuracy of the belt slippage state during belt slippage control. The device has a primary pulley (42), a secondary pulley (43), and a belt (44), and is also provided with a secondary hydraulic pressure control unit (92) that determines the instructed secondary hydraulic pressure using feedback based on the deviation (?) between the set point secondary hydraulic pressure and the actual hydraulic pressure, and that controls the secondary hydraulic pressure to the secondary pulley (43). A belt-based, continuously-variable transmission mechanism (4) is provided with a belt, slippage control means (Figure 8) that estimates belt slippage by monitoring the phase difference (?) between a vibration component included in the actual secondary hydraulic pressure and a vibration component included in the actual transmission gear ratio and that executes control to reduce the actual secondary hydraulic pressure to maintain a prescribed belt slippage state based on said estimation. The secondary hydraulic pressure control unit (92) suspends feedback control of the secondary hydraulic pressure and controls the secondary hydraulic pressure using open-loop control during belt slippage control.