MOTION ALGORITHM FOR LARGE-DISPLACEMENT DRIVING SIMULATOR

Renewed interest in developing driving simulators with large motion amplitudes has engendered simulator motion drive algorithms and computer software capable of predicting the performance of such devices for design purposes. One such computer package is described. The hardware is assumed to consist of an unrestricted turntable on top of a hexapod motion platform carried by a large-amplitude x-y carriage. Algorithms are included to represent the motion-drive washout algorithms and the physical motion of the simulator. Routines are developed to split the six linear and angular motions among the three principal hardware subsystems. The presence of an unrestricted turntable has resulted in the need to develop a new tilt-coordination algorithm to simulate sustained accelerations. By selecting a Euler angle set specifically suited to the present geometry, a considerable simplification of the washout algorithm has been achieved. Potential problems with algorithm stability and crosstalk are pointed out, and guidelines on how to avoid them are provided. Several typical car maneuvers are employed to demonstrate the features of the motion algorithm and the benefits and limitations of the hardware configuration. These maneuvers include an entry and steady turn, braking, and a single lane change. The effects of including and deleting the turntable and the x-y carriage are studied. The results are described in terms of the amounts of hardware travel used and the fidelity of the motion cues provided to the driver.