Optimal Structure Designing Of 6-Dof STEWART Parallel Manipulator

Stewart parallel manipulator is another hot spot in the field of robotics research because it made up the drawback of serial robot such as low stiffness, poor loading capacity, high joint accumulated error, and consummate the field of robotics. Parallel manipulator had rapid development incent 20 years and was widely applied in the field of motion simulation, parallel machine tool, industrial production lines, high-precision medical equipment, etc.Although Stewart parallel manipulator has many advantages, the forward kinematics solution is very difficult because the motion platform is driven by the movement of six actuator legs at the same time, which cause obvious coupling between six actuator legs and some defects, such as singular configuration, poor flexibility and so on. So avoid these defects to achieve the best performance in the design of parallel manipulator is a very difficult task.The paper analyzes the theoretical of Stewart parallel manipulator based on inverse solution. Firstly, derived the kinematics equations; then, established single rigid body and multi-body dynamics model by Newton-Euler and Kane method, especially analyzes the influence of six actuator legs to the mass matrix by a example; finally, proposed the optimization performance index of optimize Stewart parallel manipulator, so had prepared for optimizing. In order to verify the correctness of the theoretical derivation, using ADAMS to establish the parametric model and simulate in the single degree of freedom, then compare the simulation curves with theoretical calculation results to study the correctness of theoretical modeling.Before optimization, analyzed the relationship between design parameters and performance of Stewart parallel manipulator and obtained the characteristics when Stewart parallel manipulator motion along different directions; then, selected the optimization parameters, determined the objective function and constraints, selected optimization algorithms; finally, calculated and analyzed the optimization result.Finally, in order to improve design efficiency, programming the calculation program of Stewart parallel manipulator which synthesized the calculation of kinematics, dynamics, workspace, frequency, actuators and etc.