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240 Computed-Torque Control

which has a pole at some desirable location |α|<1. The design parameter α
may be selected by simulation studies. Then the controller with antiwindup
protection (4.5.23), (4.5.24) is given by

(5)

(6)

The corresponding difference equations for implementation are

(7)

(8)

A few lines of FORTRAN code implementing this digital controller are given
in Figure 4.5.9. This subroutine may be used as the control update routine
DIG for the digital simulation driver program TRESP in Appendix B.

Figure 4.5–9: FORTRAN code implementing PI controller with antiwindup
compensation.
If α=1 we obtain the special case (2), which is called the position form
and has no antiwindup compensation. If α=0, we obtain the deadbeat
antiwindup compensation

Copyright © 2004 by Marcel Dekker, Inc.