Steering Chain HIL Simulator for Steer-by-Wire Systems

Advanced control for automotive is one of the most promising research topic in the forthcoming decade. Actually, the long-term target is the substitution of most hydraulic car systems with their electronic counterparts. A bright example is set by the steering function, which has passed from pure mechanical to power assisted and recently to pure electrically power assisted function. The next step, the full electronic steering (Steer-By-Wire, SBW), is in progress. Definitively, it is going to substitute the mechanical connection with the steering wheel by wire-transmitted digital signals to one or more remote electric motors. Obviously, any innovative control strategy needs thorough hardware verification. At the early stages, or whether a real car prototype was not available, it is common practice to use hardware-in-the-loop (HIL) simulators, for fast control prototyping. In this frame, as proposed here, a high dynamic electric drive can virtually reproduce the real nonlinear load, represented by the steering chain and other external torque contributes. The paper presents the model details, the system architecture as well as the experimental validation of the complete HIL simulator.