Design and Implementation of aModified Classical Washout Filter Algorithm for ASARun Driving Simulator

Driving simulators should replicate the exact motion cues of real vehicles. To avoid an excessively large workspace, washout filters are used to generate the best motion commands within the kinematic and kinetic constraints of simulators. The most common motion cuing algorithm is the Classical Washout Algorithm (CWA), which was initially developed for flight simulators with 6-DOF Stewart platforms. ASARun is a 3-DOF driving simulator designed and built at K.N. Toosi University of Technology. It can move in heave, pitch, and roll directions. Direct use of CWA for the ASARun simulator is impossible because of two reasons. First, CWA is designed for six degrees of freedom, while ASARun has only three degrees of freedom. Second, car simulators need a wider range of lateral and longitudinal accelerations in terms of magnitude and frequency unlike flight simulators. A 3- DOF simulator cannot reproduce high frequency linear accelerations with the described CWA. In this paper, a modified version of CWA (MCWA) has been designed and implemented for ASARun. MCWA produces high-frequency accelerations differently from CWA. MCWA solves a set of equations related to high-frequency accelerations of driver’s head to find the related motion of each degreeof freedom, whereas CWA calculates linear displacements of the Stewart platform independently from its orientation. MCWA has been implemented on ASARun in real time in C#.NET environment. Experimental results for two sets of maneuvers, i.e. turning and bump, are presented using skilled drivers in order to optimize MCWA parameters to its best performance.

کلیدواژه ها:

driving simulator ، washout filter ، human perception of motion ، virtual reality