Nissan has revealed what it calls "Independent Control Steering Technology" that allows independent control of a vehicle’s tire angle and steering inputs and says it will be offered on select Infiniti models on sale within a year – although it doesn't say in what markets.
In effect it's a "drive-by-wire" steering system. The new Nissan technology replaces the mechanical connection between the steering wheel and the front wheels with electronic connections.
You turn the wheel, it sends an electronic signal to a control unit, which manipulates the signal and sends it on to an electric motor (or motors) that turn(s) the wheels. The same way the steering controls in the cockpit of an airliner moves the directional surfaces on an airliner.
Nissan says this next-generation steering technology transmits the driver’s intentions to the wheels even faster than a mechanical system and increases the driving feel by quickly and intelligently communicating road surface feedback to the driver – something other manufacturers' prototype drive-by-wire systems in Autofile's experience have failed to do.
It is also said to insulate the vehicle from unnecessary road-generated disturbances – for example, on a road surface with minor ridges or furrows, the driver no longer has to grip the steering wheel tightly and make detailed adjustments, so traveling on the intended path becomes easier.
Nissan has also developed a camera-based straight-line stability system to further enhance the system's on-centre driving capability. This technology, which Nissan claims as a world-first, improves vehicle stability by making small input angle adjustments so the vehicle will accurately trace and continue as planned in the lane it is traveling.
If the vehicle direction changes due to road surface or crosswinds, the system acts to minimize the effect of these conditions resulting in reduced steering input from the driver.
Using a camera mounted above the vehicle’s rearview mirror, the system analyzes the road ahead, recognizes the lane direction, detects changes in the vehicle’s direction, and transmits this information to multiple electronic control units as electronic signals.
If a discrepancy occurs, the system acts to reduce the discrepancy by controlling the opposing force to the tire angle. Reducing the frequency of detailed steering input adjustments promises to reduce driver fatigue, particularly on long drives.
Nissan says reliability – always a concern with drive-by-wire systems – is achieved by multiple ECUs. In the event a single ECU malfunctions, another ECU will instantly take control, and in extreme circumstances such as the power supply being disrupted, a backup clutch will mechanically connect the steering wheel and wheels via a conventional steering shaft.