Reduced Order vs. Discretized Lumped System Models with Absolute and Relative States for Continuum Manipulators

—A reliable, accurate, and yet simple dynamic model is important to analyze, design and control continuum manipulators. Such models should be fast, as simple as possible and user-friendly to be widely accepted by the ever-growing robotics research community. In this study, we introduce two new mod- eling methods for continuum manipulators: a general reduced-order model (ROM) and a discretized model with absolute states and Euler-Bernoulli beam segments (EBA). Additionally, a new formulation is presented for a recently introduced discretized model based on Euler-Bernoulli beam segments and relative states (EBR). The models are validated in comparison to ex- perimental results for dynamics of a STIFF-FLOP continuum appendage. Our comparison shows higher simulation accuracy (8-14% normalized error) and numerical robustness of the ROM model for a system with small number of states, and computational efficiency of the EBA model with near real-time performances that makes it suitable for large systems. The challenges with designing control and observation scenarios are briefly discussed in the end.