A Method for the Inverse Dynamics Analysis of Variable Geometry Trusses.

This paper presents a novel numerical approach to solving the inverse dynamics of variable geometry trusses (VGTs) with elastic elements, allowing designers to accurately and efficiently determine motor action requirements, and the time-dependent behavior of the structure. The dynamic equations have been simplified by assuming that movements of the structure are relatively slow, since VGTs are generally used in situations requiring high accuracy. Unlike existing techniques, the formulation is based on simple finite element models. The analysis is based on modal coordinates, and takes place in two stages: first, motor actions are calculated in a model with no actuator stiffness; then small-amplitude, undamped vibrations are obtained in a model that includes actuator stiffness. The method is validated by simulating a three-dimensional VGT. [ABSTRACT FROM AUTHOR]