GENERATION AND SOLUTION OF MULTIBODY SYSTEM EQUATIONS

Multibody system equations can be generated in various forms. All of these may be interpreted as results of two basic approaches, the augmentation and the elimination methods. The former method yields the descriptor form of the system motion, a set of differential/algebraic equations, and the latter the state space representation, a minimal set of pure differential equations. Both of these methods are surveyed. For simulation purposes one would like to select that set of system equations which can be generated most efficiently and for which the most efficient and reliable solution techniques are available. Numerical solution techniques for pure differential equations have been studied in great detail and they are well developed. By contrast, differential/algebraic equations have not been so thoroughly investigated. The status of development in the latter field is surveyed and recent results on improving reliability and efficiency of the corresponding solution techniques are discussed. A new method, avoiding the inaccuracies of previous techniques for solving differential/algebraic equations, is presented. © 1990.