Sensitivity coefficients, trajectories and graphs of a human head-movement model.

With time as the criterion to be optimized, the divergences from optimal head movements show systematic differences in their control signal variables with respect to single behaviours. To clarify these relationships, this study applies manipulation and mathematical analysis of the 6th-order nonlinear head movement model, using the three-fold approach of sensitivity analysis. The sensitivity analysis of the improved and refined head movement model explains the different tasks of the control parameters and their relation to the plant. It shows that width more than height of the agonistic and antagonistic pulses dominate the important behaviours of the movement: acceleration, magnitude and duration.