Task Space Approach of Robust Nonlinear Control for a 6 DOF Parallel Manipulator

摘要: The dynamics and kinematics of a parallel manipulator has been widely researched by virtue its high force-to-weight ratio widespread applications ranging from vehicle or flight simulator to machine tool despite smaller workspace than serial robot system (Merlet, 2000). Such paid special attention as typical multi-input multi-output nonlinear retain control performance. A scheme for 6 DOF can be classified into two groups: joint space based (Honegger et al., 2000; Kang 1996; Kim Nguyen 1993; Sirouspour & Salcudean, 2001) task strategy (Kang Park, 1999; Ting 1999). It is easy realize the if decoupled single-input single-output (SISO) systems activate mechanism. simplicity let many research activities pursue more specific approaches. As result, novel approaches have studied improve performance rejecting effects in equations motion 2001). Particularly, driven hydraulic-servo system, robust (Kim 2000) proposed. However, dealt with excessively conservative uncertainties including gravity known dynamic characteristics even though friction effect neglected hydrostatic bearing. On other hand, potential meet excellent performances under uncertainties: inertia, modeling error, friction, etc. may realized obtained state through costly sensor estimation methodology. H∞ (Park, 1999) adaptive (Ting examples control. there still some weak points previous researches; linearized model approach simulation study only, respectively. Another proposed Stewart platform 1996). it also shown computational results only on assumption that seems excessive. Furthermore, treatment stick-slip minimal, which give rise serious deterioration real where frictional property not negligible.