An instantaneous eigenstructure quasi-coordinate formulation for nonlinear multibody dynamics Academic Article uri icon


  • A novel method is presented to solve the equations of motion for a large class of constrained and unconstrained dynamical systems. Given an analytic expression for the system mass matrix, quasi-coordinate equations of motion are derived in a manner that generates equations analogous to the dynamics/kinematics partitioning in Eulerian rigid body dynamics. This separation is accomplished by introducing a new quasi velocity coordinate η which yields a dynamical system with an identity mass matrix. The problem of inverting a complex mass matrix is replaced by the problem of solving two first order differential equations for the mass matrix eigenfactors. Dynamic constraint equations are incorporated directly into the new η differential equation forgoing any need to solve the algebraic constraint equations simultaneously with the differential equations of motion.

author list (cited authors)

  • Junkins, J. L., & Schaub, H.

publication date

  • December 1997