Basic Gear Shifting Method for Automatic Gear Box inMild-Hybrid Vehicles Using Cost Functions

摘要

An automatic gear box for a conventional vehicle has to handle basically only the same number ofrnoperating points as its number of gears [1]. A power request by the driver is followed by a calculation ofrnnew and possible operating points for the combustion engine. The operating point with the lowest fuelrnconsumption is chosen. A Mild-Hybrid vehicle has more than one power source. The electric engine couldrnsupport the combustion engine but also could also act as an additional load. The interaction of the twornengines enables many combinations of electrical engine torque and internal combustion engine (ICE)rntorque. The best gear could only be chosen if the combination of torque with the lowest chemical andrnelectrical energy consumption is found. The calculation necessary to find this combination has to be donernfor every possible gear. The presented method combines an energy management system (EMS) based onrncost functions with a basic gear shift logic.