Methods for optimizing the efficiency of a series hybrid vehicle with multi-gear transmission

摘要

In a series hybrid vehicle, a system for determining a shift schedule for shifting a multi-gear transmission connected to a drive means is disclosed. A vehicle operator selects among a plurality of shift styles respectively representing a plurality of shift schedules variously optimized for performance or fuel economy. A performance-based shift schedule favors providing maximum power to the road by starting at the first (lowest) gear when accelerating from a stop and utilizing all available gears of the transmission. An economy based shift schedule favors energy efficiency by skipping the first gear and optionally one or more higher-numbered gears in order to bias operation of the drive means toward lower speeds and higher torque output while reducing shift frequency. The invention provides for maintaining the number of gear ratio choices provided by a transmission having relatively many distinct gear ratios, while providing for reduced frequency of shifting and driver choice of a shift schedule favoring either performance or economy.