Apparatus and method for detecting end-of-fill at clutch in automatic transmission

• Main Authors: NEELAKANTAN VIJAY A, BAI SHUSHAN
• Format: Patent
• Language: Chinese; English
• Published: 26.05.2010
• Subjects: BLASTING; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; MECHANICAL ENGINEERING; METERING BY VOLUME; PHYSICS; TESTING; THERMAL INSULATION IN GENERAL; WEAPONS

An improved method and apparatus for detecting end-of-fill at a hydraulic clutch in an automatic transmission with a variable force solenoid are provided. The method includes: initiating clutch fill mode by commanding a high current to the solenoid whereby a high fluid pressure is delivered to the clutch apply volume; monitoring clutch fill time; determining if the fill time is greater than a threshold fill time; monitoring the current (e.g., actual and filtered) being actively drawn by the solenoid during clutch fill mode in response to the fill time being greater than the threshold fill time; detecting if an aberration occurs in the current; and stopping distribution of fluid to the hydraulic clutch in response to the current aberration. Detecting if an aberration occurs preferably includes determining a change in instantaneous armature velocity, and determining if the change in instantaneous velocity is greater than a threshold change in armature velocity.