Cross-Axle Transmission Torque Vectoring: The Next Step in Automotive Safety?

Torque Vectoring Unit
(Photo: Ricardo PLC)

According to the company, Torque Vectoring technology is designed to provide an improvement in the "safe handling" limits of a vehicle. The technology enables moment-by-moment redistribution of drive-torque - either cross-axle on a two-wheel-drive vehicle or between the front and rear axles of a four-wheel-drive vehicle - in response to driver demand, vehicle speed and road conditions. In doing so, it enables the vehicle to follow the driver's intended path more faithfully, ultimately leading to a potentially safer, more enjoyable and rewarding driving experience.

Compact design The design of the Torque Vectoring unit is highly compact and can be contained with very limited intrusion into an existing differential packaging envelope, says Ricardo CEO Dave Shemmans. Its small size enables minimal reduction in drive shaft length and articulation. The novel arrangement allows the actuation system to be contained on one side of the pinion axis, providing improved packaging while allowing the unit's center of gravity to be located on the vehicle center line and ensuring side shafts of equal length.  System actuation is flexible depending on vehicle architecture - compatible with hydraulic, electro-hydraulic and electro-mechanical control strategies. The technology in the demonstration system is capable of delivering a cross-axle torque bias of 1400Nm, and a differential wheel speed delta of 20 percent, says Shemmans. Response time targets for the demonstrator vehicle have been set at a maximum of 50ms from request to start of torque activation and 100ms to achieve 90 percent of the full torque demand. "The [Torque Vectoring system] technology of this system is available for automakers and Tier 1 suppliers alike to license, offering them a means of accelerating time to market and significantly reducing development effort," says Shemmans. (Source: Ricardo PLC)