Grade-based anti-hunt timer

• Main Authors: TIPTON SCOTT A, STEINLAGE JUSTIN L, LANDES JAMES W
• Format: Patent
• Language: English
• Published: 10.03.2015
• Subjects: BLASTING; CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; ENGINEERING ELEMENTS AND UNITS; GEARING; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; LIGHTING; MECHANICAL ENGINEERING; PHYSICS; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; THERMAL INSULATION IN GENERAL; WEAPONS

A system and method are provided for grade-based anti-hunt shift control of an automatic transmission powering a machine. A shift controller determines a recommended gear in which to operate the transmission and sets an anti-hunt timer upon recommending a shift from a first gear to a second gear. The anti-hunt timer prevents a subsequent shift back to the first gear while the anti-hunt timer is running. A grade-based controller is configured to track machine operation and to determine when the machine operational factors change such that an estimated steady state gear differs from the second gear. When such a change is encountered, the grade-based controller clears the anti-hunt timer and sets a secondary timer. The clearing of the anti-hunt timer allows a downshift to accommodate the detected grade while the setting of the secondary timer prevents a subsequent clearing of the anti-hunt timer while the secondary timer is running.