thesis.final.w6

IMAGE Imgs/thesis.final.w650.gif

n = 0, 1, 2, ...

Figure 3.11 - End-of-step sampling times for Q_i.

RVs must be chosen to be meaningful functions of the system state in order to improve the

chances of attaining a limit cycle. A number of general criteria should be met:

RVs should incorporate some key element(s) of the desired cycle and should reflect

movement or position relative to the world frame. An example that meets both criteria

is "uprightness" with respect to the world vertical axis for the case of walking.

The RVs should be easily controllable. It should be possible to reach a wide range of

RV values from various initial states by choosing an appropriate parametric control

perturbation.

RVs.

For example, the system must have DOFs which can affect the chosen

For example, in the

case of a walking biped, the range of interest might correspond to configurations with

a relatively upright torso.

We should be able to estimate a target value for each RV which will keep the motion

close to a desirable limit cycle.

For example, to attain a walking limit cycle, we must

be able to determine target RV values that will keep the biped balanced.