Identification of Multimodal Pilot Models Using Ramp Target and Multisine Disturbance Signals

This paper investigates the extent to which target forcing functions consisting of multiple ramplike or steplike changes in target attitude can be used for identification of multimodal pilot models. The main question addressed is whether such signals provide enough excitation of the pilot-vehicle system to allow for reliable estimation of pilot model parameters from measured pilot control data. The compensatory control task from a previous human-in-the-loop experiment performed in a moving base flight simulator is used to define a typical multimodal pilot model identification problem. Using simulations of this control task, where different multisine and ramp target forcing function signals are used to excite the pilot-vehicle system (in addition to a multisine disturbance signal), the accuracy and consistency of pilot model estimation results are evaluated. It is found that both the bias and variance of the pilot model parameter estimates decrease with increasing ramp signal steepness. If the steepnesses of the ramps in the target signals are higher than 3 deg /s, estimation results are found to be more accurate than those obtained using a quasi-random target forcing function. This indicates that reliable pilot model identification results can be obtained using such ramp target forcing function signals.