VIRTUAL DECOMPOSITION BASED CONTROL FOR GENERALIZED HIGH-DIMENSIONAL ROBOTIC SYSTEMS WITH COMPLICATED STRUCTURE

This paper presents a systematic adaptive control strategy which can a ccomplish a variety of control objectives (position control, internal force control, constraints, and optimizations) for the generalized hig h dimensional robotic systems (GHDRS) without restriction on target sy stems. Based on the concept of virtual decomposition by which a GHDRS is virtually decomposed into several objects and base-floating open ch ains, the motion control problem of the original system is converted i nto that of each object and that of each open chain, individually, whi le the internal force control as well as the constraint force control may be performed with respect to each object only. This feature makes it possible to implement the control algorithm of each subsystem in mo dularly structured hardware which can be integrated to form any specif ic robot controller dedicated to a specific application. In the sense of Lyapunov, it is the first time to declare that the dynamic coupling between every two physically connected subsystems can be completely r epresented by the so-called virtual power flows (VPF's) at the cutting points between them. Asymptotic stability of the complete system can be ensured by choosing the system Lyapunov function as the sum of all nonnegative accompanying functions assigned for the subsystems. Some p ossible applications based on the proposed approach are discussed. Fin ally, computer simulations of two PUMA 560 arms transporting a common object along a prespecified trajectory are carried out to verify the s tability and robustness issues of the system.