| Active four-wheel steering systems greatly enhance the dynamic characteristics of automotive vehicles. The performance of a selected 4WS control algorithm dictates the magnitude of improvement. Typically, the evaluation of a 4WS controller involves computer simulation providing reasonable approximations of a vehicle's dynamics. However, hardware effects are not incorporated into results. Hardware-in-the-loop simulation includes the influence of hardware components, realizing inefficiencies and phase delays of the physical system. Therefore, estimations of actual controller behaviour are improved.; The performance of two 4WS controllers is evaluated through hardware-in-the-loop simulation. Development of a 4WS interactive testbed is outlined, including a detailed description of hardware elements. Simulation and control software operation is described, indicating the method of real-time execution. An overview of system testing is provided, including frequency response trials, following the selection of PI controller gains. Finally, hardware-in-the-loop simulations are performed for several steering maneuvers, and results are compared to those of multibody simulations incorporating a complicated vehicle model. |
