Nissan Direct Adaptive Steering

Autonomous cars have many hurdles to clear before reaching consumers, but they're coming. Nissan, Volvo and Mercedes Benz have pledged to bring self-driving cars to showrooms by 2020. This year, Nissan's Infiniti Q50 luxury sedan debuted one of the biggest steps yet towards that goal: the first consumer steer-by-wire system. 

Another major function of the Direct Adaptive Steering is the newly developed straight-line stability system. If the vehicle’s line of travel deviates from a straight path, the Direct Adaptive Steering enhances the car’s handling characteristics by producing fractional sensations of resistance as feedback from the steering, helping the driver keep a straight line of travel and reducing the need for course corrections in a smooth and natural way. The feedback is so subtle that a driver may not notice it.

Direct adaptive steering bypasses the mechanical connection between the steering wheel and the wheels that meet the road. Sensors measure how a driver turns the wheel and send that data through an electronic controller to actuators, which, in turn, pivot the steering rack. (For safety, two backup controllers provide redundancy.) Because there’s no physical link between the road and the steering wheel, drivers don’t feel jarring bumps or vibrations, but the system does electrically simulate natural steering resistance. Computers vary steering ratio and power assist for easier low-speed maneuvers and high-speed stability.