Steer-by-Wire (SBW) system offers a number of benefits over conventional steering systems especially economics of fuel. This system uses the electrical connection between the steering wheel and the vehicle’s wheels instead of mechanical ones. However, steering force feedback to the driver must be carefully generated to create useful road feeling. Therefore, to test a SBW system, a test rig with both Hardware-In-the-Loop and Human-In-the-Loop is desirable. This can decrease error from complicated mathematical models and can test interaction between the driver and the proposed SBW system. This thesis presents a development of Human-Hardware-In-the-Loop (HHIL) system which combines a driving simulator and a Hardware-In-the-Loop simulator that consists of tire, suspension, and steering system. Vehicle model and torque’s model are used for generating road feeling via torque feedback at steering wheel. A linear approximated Dahl model and a linear model at different torque’s gains are applied to evaluate torque feedback scheme of SBW system. NI CompactRIO and PC running real-time program (xPC) are chosen as the low level hardware controller and as the car’s dynamic simulator respectively. A dedicate PC is also used for rendering visual environment, which was developed with C language and OpenGL library, and also for keeping and supplying data of the environment. HIL system and driving simulator system can run at 500 and 100 Hz, respectively. Because of the limitation of communication equipments, these two systems can operate together at 20 Hz. HHIL simulator is used for evaluate SBW system in which Fitts’ law was applied to analyse the difficulty and fatigue of lane keeping task. The results show the relation between deviation from experiment’s track and number of driving laps which can explain apparently the difficulty of driving. It is found that driving task is easier in general with more torque feedback. However, further study is needed for fatigue analysis.
