Patent ID: 8977454
Filing Date: 2015-03-10
Classification: F16H,Y10T

Abstract:
1. A system for grade-based anti-hunt shift control for controlling a transmission powering a machine, the transmission being an automatic transmission having a plurality of discrete gears, each gear corresponding to a distinct transmission ratio, the system comprising: a shift controller configured to determine a recommended gear in which to operate the transmission; an anti-hunt timer having a primary duration, wherein the shift controller is further configured to set the anti-hunt timer upon recommending a shift from a first gear to a second gear adjacent the first gear, wherein the anti-hunt timer prevents a subsequent shift from the second gear back to the first gear while the anti-hunt timer is running; a grade-based controller configured to calculate an estimated steady state gear based on at least one of current grade and machine load and to clear the anti-hunt timer when the estimated steady state gear differs from the second gear; a secondary timer having a secondary duration, wherein the grade-based controller is further configured to set the secondary timer upon clearing the anti-hunt timer and is disabled from again clearing the anti-hunt timer until the secondary timer expires.