| 摘要 |
Simulated or "mock" continuously variable transmission shift strategies are used in an electromechanically actuated automotive transmission having reduced ratios steps in its upper ratio ranges. In one described embodiment, a 12-speed truck transmission consists of a five-speed main section and an auxiliary section that includes splitter and range sub-sections to provide the 12 ratios. Separate shift strategies are directed to fuel economy and power optimization modes; driver throttle demand determines the mode. Both strategies are targeted to the upper gear ratios, which represent the ratios subject to approximately ninety percent (90%) of vehicular operation. In the described embodiment, the applicable affected ratios are gears 7-12. In the described embodiments, the shift strategies are carried out by embedded software subject to the command of an electronic power train control module. Both strategies are operated as direct functions of engine torque, transmission input shaft speed, and road speed. |
