AUTOMATIC MODEL GENERATION FOR MODULAR RECONFIGURABLE ROBOT DYNAMICS

In control and simulation of a modular robot system, which consists of standardized and interconnected joint and link units, manual derivati on of its dynamic model needs tremendous effort because these models c hange all the time as the robot geometry is altered after module recon figuration. This paper presents a method to automate the generation of the closed-form equation of notion of a modular, robot with arbitrary degrees-of-freedom and geometry. The robot geometry we consider here is branching type without loops. A graph technique, termed kinematic g raphs and realized through assembly incidence matrices (AIM) is introd uced to represent the module assembly sequence and robot geometry. The formulation of the dynamic model is started with recursive Newton-Eul er algorithm. The generalized velocity, acceleration, and forces are e xpressed in terms of linear operations on se(3), the Lie algebra of th e Euclidean group SE(3). Based on the equivalence relationship between the recursive formulation and the closed-form Lagrangian formulation, the accessibility matrix of the kinematic graph of the robot is used to assist the construction of the closed-form equation of motion of a modular robot. This automatic model generation technique can be applie d to the control of rapidly reconfigurable robotic workcells and other automation equipment built around modular components that require acc urate dynamic models.