An automated transmission is also known as a sequential gearbox. A sequence means roughly, 'order' or 'cycle' and indicates here, the exact succession of the gear-speeds, primarily when up-shifting, in contrast to the complete freedom of choice with the manual gearbox. An advantage is, among other things, the elimination of the torque-converter with its unfavourable efficiency.The sequential gearbox actually, has already been around for a long time. E.g., most motorcycle and moped gearboxes fit this description. Their gears are selected by a gear shift pedal, and except for the first gear, one after the other, changed up and also, one after the other, down again, this is not always the case with an automatically changing gearbox.
The operation can be the same as with the fully-automatic gearbox. Here a operating error is practically impossible. However, the sequential gearbox originates from the manual gearbox with clutch. Its activity is taken over by an electric motor or by central hydraulics (see figure above). The control module processes the driving speed, position of the accelerator pedal and selector lever and possibly also additional parameters concerning the gear selection. When operating the clutch the RPM has an additional meaning. The signals available in the engine control module can also be received through a CAN-Bus. It would thus be possible to also analyse the engine temperature, e.g., to lower the gear changing points when the engine is cold.
The changing operations of present sequential gearboxes are a little too slow, as a rule, for sporty driving. This can be remedied by the twin-clutch gearbox. Moreover, a skilled driver can control the reversing of a vehicle with a customary, foot-operated clutch a little better. Not only do learner drivers seem to have difficulties with letting in the clutch, but also the electronics do as well.Nevertheless, the controlling device operates, e.g., in the determination of the gear-changing points, more rationally than most drivers. Thus, the guaranteed lowest consumption is available with certain vehicles from the manufacturer's selection, only in the ECO mode of the sequential gearbox. 10/08