Dynamic Modeling and Control of a 6-DOF Parallel-kinematic-mechanism-based Reconfigurable Meso-milling Machine Tool

In this thesis, a methodology for rigid body dynamic modeling and control design is presented for a 6 degree-of-freedom (DOF) parallel-kinematic-mechanism-based reconfigurable meso-milling machine tool (RmMT) with submicron tracking accuracy requirement. The dynamic modeling of the parallel kinematic mechanism (PKM) is formulated using the Lagrangian method with the application of principle of energy equivalence and coordinate transformations to separate the mechanism into serial sub-systems. The rigid body gyroscopic force is also modeled using this approach and its effect as a disturbance is analyzed and compensated. The contour errors for both position and orientation are formulated to increase machining accuracy. The dynamic model of the system is linearized through feedback linearization and the contour error based feedback control law is formulated using the convex combination design approach to satisfy a set of design specifications simultaneously. The dynamic model and its control methodology are simulated and verified within the MATLAB Simulink environment.MAS