48

iii

Constructing and Applying the Discrete System Model

3. 7. 2

Once an RV target has been chosen, the discrete system model is reconstructed and applied at each

step as shown in Figure 3.20.

In general, a single fixed model is not sufficient to represent all

possible steps.

While RVs provide a reduced, low dimensional representation of system state,

they are also an incomplete and ambiguous representation of the system state.

For example, the

chosen RVs use position information and no velocity information.

Such unobserved parts of the

system state cause variations in both Q^nomand J.

Figure 3.21 illustrates this idea.

This result is

evident in graphs of Figure 3.16 and Figure 3.17 where both the average slope and the offset of

the curves can vary from one step to the next.

lateral control dimension.

These variations are especially apparent in the

Figure 3.20 - Balancing process for each step.