Method of estimating gear stage of transmission and estimating system of gear stage of transmission

摘要

PROBLEM TO BE SOLVED: To provide an estimation method of a transmission gear stage which can determine a gear stage of a transmission at traveling without installing a sensor for detecting the gear stage in the transmission, and an estimation system of the transmission gear stage.SOLUTION: In each gear stage (i), an input-side rotation number calculation value Neic(i) being a calculation value of an input-side rotation number Nei with respect to an actual output-side rotation number Neom is calculated from a gear ratio of the gear stage and a final gear ratio, an input-side rotation number difference &Dgr;Nei(i) is calculated by subtracting the value Neic(i) from the actual input-side rotation number Neim, the input-side rotation number difference &Dgr;Nei(i) is divided by the actual input-side rotation number Neim, an absolute value thereof is set as an input-side rotation number difference rate Rei(i), and the gear stage (i) whose input-side rotation number difference rate Rei(i) at the calculated gear stage (i) becomes minimum is selected, and set as the gear stage at a time point at which the estimation is performed.