Fig.2.5 Feed-forward control principle

Conventional signs:

1. Program block;
2. Control device;
3. Controlled process;
4. Measuring device.

Such an expression is cumbersome, so we may insert some dimensionless variables:

(2.5)

where:

- basic characteristics.

Relative characteristic steepness is called constant-error behavior (constant-error response).

(2.6)

If this characteristic is rectilinear then it’s convenient to choose nominal values of variables:

(2.7)

So static regulator results in the stabilization regime with static error.

Static indicator – max static error at the change in the load from idle to nominal regime.

If static error isn’t admissible then we must go to astatic regulation.

But it’s necessary to mention the difference in terminology used in the Soviet and Russian scientific literature - static and astatic regulation.

These terms aren’t used in American and English scientific literature.