| 摘要 |
PURPOSE: To perform line pressure control in a wide condition without generating unstable operation state, by independently utilizing each of a closed loop pressure control strategy and at least one open loop pressure control strategy. CONSTITUTION: During starting, a logic switch 41 connects a line 42 with an output line 43, provides a signal generated in an open loop schedule 35 for a PWM generator, and controls line pressure of a hydraulic device. An open loop 100% control strategy 36 can be utilized. Once a lock up of a clutch has been achieved, the logic switch 41 is connected to an output line 64 of a closed loop pressure control strategy, a PI actuation control signal from a gain control box 55 and an integrator 61 is sent to the PWM generator based on deviation between a pressure setting point and a line pressure signal PCLU to control a PWM solenoid valve with duty. Thus, a line pressure control system can be actuated in a wide condition without generating unstable operation state. |
