Nissan to deliver steer-by-wire technology within a year
18 October 2012
Nissan has unveiled steering technology that allows independent control of a vehicle's tyre angle and steering inputs without relying on a mechanical linkage between the steering and road wheels.
Nissan's steer-by-wire technology (photo courtesy of Nissan Motor Co)
Nissan's steering technology reads the driver's intentions from steering inputs and controls the vehicle's tyre movements via electronic signals. This transmits the driver's intentions to the road wheels faster than a mechanical system while still communicating road surface feedback to the driver.
Nissan says its system controls and insulates the vehicle from unnecessary road-generated disturbances to deliver only the necessary performance feel to the driver. For example, even on a road surface with minor ridges or furrows, the driver no longer has to grip the steering wheel tightly and make detailed adjustments.
The company has also developed a camera-based straight-line stability system to enhance on-centre driving capability. This improves vehicle stability by making small input angle adjustments so the vehicle will accurately trace and continue as planned in the lane it is travelling. If the vehicle direction changes due to road surface or crosswinds, the system acts to minimise the effect of these conditions resulting in reduced steering input from the driver.
Using a camera mounted above the vehicle's rear view mirror, the system analyses the road ahead, recognises the lane direction, detects changes in the vehicle's direction, and transmits this information to multiple electronic control units. If a discrepancy occurs, the system acts to reduce it by controlling the opposing force to the tyre angle. By reducing the frequency of detailed steering input adjustments, which are a cause of fatigue on long drives, the driver's workload is reduced significantly.
Redundancy is built into the system so that in the event of a single controller malfunction, another will instantly take control. In extreme circumstances, such as the power supply being disrupted, a back-up clutch will act to connect the steering wheel and wheels mechanically, ensuring continued safe travel.