Control for engaging start ratios in controller-assisted, manually shifted, splitter-type compound transmission

A compound vehicular transmission system (10) comprising:

• a compound splitter-type mechanical transmission (16) having an input shaft and an output shaft, said input shaft connected to an engine (12) by a master friction clutch (14), said transmission having a main transmission section (16A) connected in series with a splitter-type auxiliary section (16B), said main transmission section defining a plurality of selectable ratios engageable by jaw clutches, said auxiliary transmission section (16E) interposed between said main transmission section (16A) and said output shaft (20);
• a splitter actuator (46) for selectively causing said splitter section to be shifted into a selected one of a first splitter ratio, a second splitter ratio, or a splitter-neutral position, and
• a controller (48, 36) for receiving input signals (68) and processing same according to logic rules to issue command output signals (70) to system actuators including said splitter actuator (46), said logic rules including rules for determining vehicle speed, engaged or disengaged condition of the master clutch, and a shift into a main transmission section ratio and into main transmission section neutral and effective, upon sensing vehicle speed being less than a reference value, said master clutch being disengaged and a shift into main transmission section neutral, to cause said splitter section to be shifted into the splitter-neutral position, and said logic rules also including rules for determining engine speed and causing said splitter section to be shifted into splitter-neutral requiring sensing that engine speed is greater than zero.