Symbolic calculation of zero dynamics for nonlinear control systems

Abstract

The calculation of the zero dynamics of a nonlinear system is of advantage in the design of controllers for this system. Because the calculation is difficult to do by hand, symbolic algebra programs are used. To access the usefulness of these programs and to solve some design problems, a MAPLE procedure, ZERODYN, is written to calculate the zero dynamics symbolically. The procedure can, however, not solve all problems, mainly because general symbolic algebra programs have insufficient capabilities to solve sets of nonlinear equations and partial differential equations. A realistic analysis problem shows this