CONTROL UNIT OF AUTOMATIC TRANSMISSION

摘要

An electronic control unit that is used in an automatic transmission to regulate oil circulation. The electronic control unit includes a switcher that supplies an electric current to a linear solenoid, a current detector that detects an actual electric current value of the solenoid, a target current calculator that calculates a target electric current value, a feedback controller that sets a duty ratio to match the actual electric current value to the target electric current value and to generate a Pulse Width Modulation (PWM) signal having the set duty ratio, and a corrector that determines whether a coupled oscillation has occurred by obtaining oil pressure information of the hydraulic circuit and to correct the PWM signal when determining that the vibration has occurred.

主权项

1. A control unit of an automatic transmission that has a hydraulic circuit in which at least one of a plurality of hydraulic valves disposed in an oil circulation part of the hydraulic circuit is operated by a solenoid, the control unit comprising:
a switcher provided on a power supply path and switching ON and OFF of a supply of a solenoid electric current flowing in the solenoid; a detector detecting an actual value of the solenoid electric current flowing in the solenoid; a microprocessor, the microprocessor configured to include
a feedback controller setting a duty ratio so that the actual value of the solenoid electric current follows a target value of the solenoid electric current, based on the detected actual value of the solenoid electric current, and by obtaining the target value of the solenoid electric current, and generating in a preset cycle a (Pulse Width Modulation) PWM signal with the set duty ratio to supply the PWM signal to the switcher; and a corrector determining whether a coupled oscillation of the plurality of hydraulic valves coupled via oil in the hydraulic circuit has occurred by obtaining oil pressure information from the hydraulic circuit and correcting the PWM signal upon determining that the coupled oscillation has occurred, wherein the corrector corrects the PWM signal to have a corrected state of the solenoid electric current, in which at least one of an amplitude and a cycle of the solenoid electric current in the corrected state is different from a non-corrected state of the solenoid electric current.