Research On Parallel Manipulator And Parallel Micro-Motion Stage

With the development of a Planar 3-RRR parallel manipulator, kniematic, static and dynamic performance of this manipulator is studied in this thesis. Kinematic model is firstly derived based on the constraint conditions of parallel manipulator, inverse and direct position analysis is done as well, and workspace is computed through a geometry methodology. Relationship between input and output velocities is established employing the concept of Jacobian matrix. A uniqueness definition is made to achieve exclusive inverse position solution, and a region searching algorithm is invented to obtain comprehensive direct position solutions efficiently.A singularity threshold concept is then brought forward to estimate the singularity of parallel manipulator, and visualize the distribution of singularity spots in workspace. Accuracy of parallel manipulator is estimated by condition number criterion, and a 2-norm criterion is brought in to evaluate the motion accuracy under the influence of input error. A structure error model is created to reveal the relationship between structure parameter error and output error, and a new algorithm of structure parameter calibration is introduced to eliminate the influence of structure error.A rational control strategy is adopted to drive the parallel manipulator, namely motion data working out by PC and control signal generated by MCU, and this strategy posses advantages such as computation takes less time, trajectory is visible, and reprogramming of MCU is easier, which make this system more flexible. GUIs are created to facilitate kinematics simulation and motion data generation, and the interface is therefore friendly.Finally, based on studies of planar 3-RRR parallel manipulator and development, a structure optimization study of parallel micro manipulator is done under the criterion of condition number, in order to make it isotropic and achieve high resolution as possible, theoretical precision is then given by computation. Furthermore, advice about control strategy of micro manipulator is given based on computation. All above work paves the way for the successful research of parallel micro-motion stage.