On the Adjoint Formulation of Design Sensitivity Analysis of Multibody Dynamics

A modified Adjoint method is presented, in which computation can be distributed to 2d+2 processors, where d is the number of degrees of freedom of the multibody system, and the Adjoint backward initial value problem (IVP) is replaced by a boundary value problem (BVP), which is solved through a backward multiple shooting algorithm. In the equivalent BVP formulation, each time-step is solved in the backward direction, but time-steps advance in the forward direction. As a result, the memory load for storing generalized coordinates during integration of the DAE of motion, is minimized. The specific objectives are (...) to develop a new method, called the Piecewise Adjoint method, that (1) requires the integration of a number of DAE that does not depend on the number of design parameters; (2) has a parallel computational structure; (3) progresses forward in time; and (4) minimizes the memory load required by the backward integration of the Adjoint DAE.