New Type Parallel Machine Tool Motion Control And Related Technology Research

Based on the infrastructure of C-Type parallel CNC milling machine, the3-(2SPS) parallel mechanism with redundant actuation, the problem of avoiding singularity and the singular transport, drive dynamic, the definite solution of kinematics inverse in real time, real-time evaluation and optimization, interpolation strategy are studied to support drive and real-time control system.Firstly, introduce the characteristics of the parallel mechanism, analyze the geometry structure and constraints, and establish the kinematics equation. Based on the equation, the distribution of singular configuration and the influence of redundant actuation on singularity are analyzed; then built the transfer function of branched chain drive system, analyze the stability and error problem, and confirm the impact factor of dynamic performance. The performance indexes of the flexibility, bearing ability and angular rigidity are defined. Analyze the performances of the parallel manipulator with additional redundant sliding and the manipulator with slipper block fixed. According the comparison of performance atlas, the norms used for optimization are established to keep the relatively optimal performances.At last, according to the character of parallel mechanism and the needs of real-time control, interpolation algorithm used in the path control of the movable platform and joint motion are studied. A two-step interpolation strategy is proposed, including the rough interpolation and the precise interpolation. In Cartesian space, the algorithm of line interpolation、circle interpolation and NURBS interpolation are studied to meet various requirements of machining precision. In actuator, PVT interpolation mode is introduced. At the same time, the principle errors in different mode are analyzed. As a matter of fact, trajectory optimization and the optimization of kinematics inverse are same in essence. Combine with the suitable norms, the simulations of trajectory planning are done. The result shows that under the situation of a regulated path of movable platform, the performances can be kept well by adjusting the movement of slipper block.