System and Method for Decreasing Ratio Changing Time Electronically Enhanced Powertrain Systems

摘要

A system and method for decreasing the time required to complete a ratio change in an electronically enhanced powertrain system (10) is provided. The powertrain system (10) includes a number of devices for providing a retarding torque to engine rotation to increase the decay rate of the engine speed during an upshift. These devices include an engine brake (32) and an input shaft brake (38). A retarding torque is also provided by increasing engine accessory load by controlling various engine accessories such as a cooling fan (30), an air compressor, a hydraulic pump, an air conditioning compressor (34), and an alternator.