71

2.The above holds for final perturbation scalings, K^*, far from the sample point scalings

used to construct the linear discrete system model.

That is, the model applies over a

large change in state. Table 4.1 shows this for a number of desired values of Q^d
.

At

Taken together, these suggest the possibility of controlling non-trivial aperiodic motions in a

similar way to the periodic motions of this thesis.

Such motions would typically require a much

larger controllable range of Qthan cyclic motions since they typically involve a larger change from

initial state to final state.

sitting in a chair.

An example of such an aperiodic motion would be standing up from

Table 4.1 - Results of first controlled step using stance-COM RVs.

K^*
fwd^{and K}lat^{*are final stance hip perturbation scalings in}

degrees. Sample scalings for construction of linear models
are [K_fwd,K_lat] = [±5,±1] (compare to K^*
fwd^{and K}lat^*in

table).

Finally, because the particular choice of perturbation is the primary cause of the poor stability

results with the stance-COM, it is quite possible that a better choice of perturbations might give

better results. Using a stance ankle pitch perturbation to vary the force with which the stance foot

pushes off the ground is one possible example.