Torque vectoring

The flagship 1996 fifth-generation Honda Prelude was equipped with an Active Torque Transfer System (ATTS) torque-vectoring differential driving the front wheels; it was known in different markets as the Type S (Japan), VTi-S (Europe), and Type SH (North America).

[3] In essence, ATTS is a small automatic transmission coupled to the differential, with an electronic control unit actuating clutches to vary the torque output between each driven wheel.

[4] At about the same time, the Lancer Evolution IV GSR was equipped with a similar Active Yaw Control (AYC) system in 1996.

[5] AYC was fitted to the rear wheels and similarly works to counteract understeer through a series of electronically-controlled clutches that control torque output.

A torque vectoring differential requires an electronic monitoring system in addition to standard mechanical components.

The function is independent of technology and could be achieved by driveline devices for a conventional powertrain, or with electrical torque sources.

The differential also increases torque to the opposite wheel, helping balance the power output and keep the vehicle stable.

If needed, the differential can transfer more torque between the front and rear wheels to improve vehicle performance.

In this case the torque vectoring between the front and rear axles is just a matter of electronically controlling the power distribution between the two motors, which can be done on a millisecond scale.

[11] A special transmission unit was used in the experimental 2014 car MUTE of the Technical University of Munich, where the bigger motor is providing the driving power and the smaller for the torque vectoring functionality.

[11] Research is taking place into using torque vectoring to actively steer railway wheelsets on the track.

Claimed benefits include a drastic reduction of wear on both track and wheel and the opportunity to simplify or even eliminate the mechanically complex, heavy and bulky bogie.

Stored Energy Technology Limited has built and successfully demonstrated their torque vectoring Actiwheel system which employs a wheel hub motor of their own design.

[17] German Aerospace Centre unveiled a full scale mockup of torque vectoring running gear intended for their Next Generation Train at Innotrans 2022.