Fig. 10.

Bode amplitude and phase plots of the linearized coupled model, for different values of hand impedance. A: stiffness (K) = 100 N/m, and damping coefficient (B) = 10 N·s/m, typical for the low-frequency group. B: K = 200 N/m, and B = 15 N·s/m, typical for the high-frequency group. Note that the pendulum amplitude plots have different scales in A and B. Phase plots of the cart and pendulum are superimposed to highlight the synchronization of their movements. For comparison, the gray histogram represents the distribution of frequencies adopted by participants in the experiment (identical to Fig. 3). The part of the graph right (respective left) of the antiresonance frequency is grayed out because it is not relevant for system A (respective B) with values of K and B for which the frequency analysis was performed. deg, Degrees.