Active steering systems - HICAS/Super HICAS

High Capacity Active Steering (HICAS)

HICAS development history

“HICAS” four-wheel steering system

In 1986, Nissan launched their HICAS system on the rear axle of the R31 Skyline Coupe.

Configuration of HICAS II system

Principle layout of the E-M SBW 4WS conversion mechatronic control system [NISSAN 1989 -- HICAS]

Configuration of SUPER HICAS system

General arrangement of Nissan Super HICAS 4WS system (Nissan Europe)

Super HICAS is controlled by a relatively simple open-loop control system. The desired vehicle path dictated by the driver is determined based on signals from the vehicle’s velocity sensors and the steering wheel angle sensor. The appropriate rear-wheel steer angle is then calculated by the system’s ECU. The ECU then actuates a servo valve, which applies pressure to a spring-centered hydraulic cylinder. The stroke of this hydraulic cylinder pivots the rear wheel to the required angle.

Nissan continued to develop the HICAS system into the “Super HICAS” four-wheel steering system, which was featured on the Nissan 300ZX and several Infiniti models between 1989 and 1996.