Patent ID: 6364810
Filing Date: 2002-04-02
Classification: B60W,F16H,Y10S,Y10T

Abstract:
A method for controlling splitter shifting in a controller-assisted, manually shifted vehicular transmission system (10) comprising an internal combustion engine (12) driving an input shaft (24) of a compound transmission (16) having a multiple-ratio main section (16A) shifted by a shift lever (26) manually movable in a shift pattern and a splitter auxiliary section (16B) connected in series with said main section, said splitter auxiliary section shiftable to a selected one of (i) splitter-high ratio, (ii) splitter-neutral and (iii) splitter-low ratio, a splitter shift mechanism (28) for automatically implementing splitter shifts and a controller (54) for receiving input signals (52) indicative of system operating conditions and for processing same according to predetermined logic rules to issue command output signals (56) to system actuators, including said splitter shift mechanism, said method comprising the steps:sensing one of (i) a currently engaged condition of the main section and (ii) an intended engaged condition of the main section; determining if the splitter section is in the splitter-high, splitter-neutral or splitter-low position; determining a target engine speed (EST) under existing vehicle operating conditions; if (i) said main section is one of (1) engaged and (2) engaging in a known ratio and (ii) said auxiliary section is in splitter-neutral; (a) determining expected engine speed if said auxiliary section is engaged in splitter-high ratio (ESSPLITTER-HIGH) and expected engine speed if said auxiliary section is engaged in splitter-low ratio (ESSPLITTER-LOW), and (b) commanding the splitter auxiliary section to be engaged in a splitter ratio determined as a function of said target engine speed and said expected engine speeds.