Automated manual transmission
It is essentially a conventional manual transmission[1][2][3][4][5] equipped with automatic actuation to operate the clutch and/or shift gears.
Many early versions of these transmissions that are semi-automatic in operation, such as Autostick, which automatically control only the clutch – often using various forms of clutch actuation, such as electro-mechanical, hydraulic, pneumatic, or vacuum actuation[6][7] – but still require the driver's manual input and full control to initiate gear changes by hand.
[8] Modern versions of these systems that are fully automatic in operation, such as Selespeed and Easytronic, can control both the clutch operation and the gear shifts automatically, by means of an ECU, therefore requiring no manual intervention or driver input for gear changes.
[9][10] The usage of modern computer-controlled AMTs in passenger cars increased during the mid-1990s, as a more sporting alternative to the traditional hydraulic automatic transmission.
During the 2010s, AMTs were largely replaced by the increasingly widespread dual-clutch transmission, but remained popular for smaller cars in Europe and some developing markets, particularly India, where it is notably favored over conventional automatic and CVT transmissions due to its lower cost.
Several different systems to automate the clutch and/or shifting have been used over the years, but they will generally use one of the following methods of actuation for the clutch and/or shifting: hydraulic or electro-hydraulic actuation,[12] electro-mechanical,[13] pneumatic,[6][14][15] electromagnetic,[16][17][18] or even purely electrical using an electric motor.
[13][19] When shifting gears, the driver selects the desired gear with the transmission shift lever, while electronic sensors and actuators connected to a TCU (transmission computer) or microprocessor will automatically operate the clutch and throttle to match revs and to re-engage the clutch in milliseconds.
Most modern implementations of this transmission function are in a sequential mode, where the driver can upshift or downshift by only one gear at a time.
[27][28] Other clutchless manual transmissions included the 1967 NSU Ro 80 (3-speed Fichtel & Sachs) and 1967 Porsche 911 (4-speed Sportomatic), both of which used vacuum-actuated clutches and hydraulic torque converters.
BMW's involvement with automated manual transmissions began in 1993, when the "Shift-tronic" 6-speed semi-automatic was offered on the Alpina B12 coupe (based on the E31 850CSi).
[43][44] Using an automated clutch paired to a standard H-pattern shifter (as per the Ferrari Mondial T), the transmission was supplied by LuK and fitted to less than 40 cars.
The SMG-III could achieve a shift time of 65 milliseconds in its most aggressive mode[48] From 2002 to 2007, the third-generation Toyota MR2 was available with an "SMT" 6-speed automated manual transmission.
[50][51] The E-gear was used on the successors to the Murciélago and Gallardo, and it was also available on the 2007-2012 Audi R8 (Type 42), marketed as the "R-tronic" transmission.
