More gears, more challenges

Many strategies, as well as key software and hardware aspects related to controllers, networks, sensors, and actuators, must be considered to keep automatic transmissions shifting smoothly as more gears are added to improve fuel economy.

Transmission developers who added gears to meet tighter fuel economy/consumption requirements are adopting a range of strategies to make sure that efficiency and driveability are also improved. Reducing loss, communicating with engines, and maximizing module usability are among the challenges facing design teams.

Automatic transmissions have evolved rapidly since the days when six gears were derided as a marketing ploy. Six gears are now common, while seven-, eight-, and nine-speed units are emerging. In all these systems, one of the big challenges is to avoid wasting any energy.