In our work, a Lie-theory-based accurate dynamic modeling scheme is given for multi-DOF serial robots with/without external loads, where we propose the improved Stribeck friction model involving the nonlinear dependence of friction on the velocity–load and introduce a novel linearizable nonlinear dynamic model. On the basis of the interaction between different optimization criteria, we modify the optimization technique for the design of optimal excitation trajectories used in dynamic identification. Finally, several experiments are carried out on the seven DoFs Franka Emika robot, and the experimental results reveal twofold:(1) the proposed dynamics scheme has better fitting accuracy and higher versatility and (2) the optimal excitation trajectory generated via the proposed criterion requires shorter optimization time while ensuring the quality of identification results compared to others, which can provide advantages for fast, robust, and accurate identification.In the next work direction, the time-varying temperature-dependent friction phenomena will be researched for fine modeling and compensation. Simultaneously, the developed friction will be seamlessly extended to the dynamic friction model and applied to robot dynamics in a unified way. Concurrently, there is a need for further exploration at the robot planning level in conjunction with advanced intelligent control theories.
