Multibody System Dynamics with Constraints: The 'Closed Loop' Problem

摘要

The governing equations for constrained multibody systems are formulated in a manner suitable for their automated, numerical development and solution. Specifically, the 'closed loop' problem of multibody chain systems is addressed. The governing equations are developed by modifiying dynamical equations obtained for Lagrange's form of d'Alembert's principle. This modification, which is based upon a solution of the constraint equations obtained through a 'zero eigenvalues theorem,' is, in effect, a contraction of the dynamical equations. It is observed that, for a system with n generalized coordinates and m constraint equations, the coefficients in the constraint equations may be viewed as 'constraint vectors' in n-dimensional space. Then, in this setting the system itself is free to move in the n-m directions which are 'orthogonal' to the constraint vectors. (Author)