Patent ID: 8862351
Filing Date: 2014-10-14
Classification: B60W,F16H

Abstract:
1. A method of controlling a transmission for a machine to at least partially avoid drive train oscillation, the transmission having a variator and a plurality of contiguous selectable operating ranges, one or more pairs of adjacent operating ranges being separated by respective synchronous points, the method comprising: operating the transmission in a first operating range; detecting whether a current speed ratio defined as an output speed of the variator divided by an input speed of the variator is within a first predetermined range of a speed ratio associated with a first synchronous point lying between the first operating range and the second operating range; determining a desired speed ratio; determining if the desired speed ratio is within a second predetermined range of the speed ratio associated with the first synchronous point; determining if a rate of acceleration of the machine is below a threshold acceleration; and preventing a shift between the first and second operating ranges and controlling the variator to hold the current speed ratio at or near the first synchronous point if the desired speed ratio is within the second predetermined range or the rate of acceleration of the machine is below the threshold acceleration.