Based On The 3 - Type Of Rpr Mechanism Of Mixed Multi Degree Of Freedom Wind Tunnel Test Platform Kinematics Modeling Research

The post stall capacity has become one of the important technical characteristics of advanced fighters such as the fourth-generation fighters and it also has been the basic connotation belongs to super maneuverability of modern fighters. The post stall capacity of fighters can be assessed by Wind Tunnel Based Virtual Flight Testing. And multi-degree of freedom model support technology is the key point of Wind Tunnel Based Virtual Flight Testing.A wind tunnel testing bed which is based on3-RPR planar parallel manipulator was given in this paper, and the structure, direct and inverse kinematics, singularity and workspace of the testing bed was investigated, which would lay the theoretical foundation for the use of the testing bed in the wind tunnel test.Firstly, an overview to the post-stall maneuver and Wind Tunnel Based Virtual Flight Testing was presented, the recent research and the research achievements about the wind tunnel testing beds was analyzed. The structure of the wind tunnel testing bed which is based on3-RPR planar parallel manipulator was discussed and the corresponding test data of the test model that was acquired in wind tunnel test was introduced.Secondly, the paper investigated direct and inverse kinematic problems of the wind tunnel testing bed which is based on3-RPR planar parallel manipulator and established the closed-form solution for inverse kinematic problem and the numerical solution for direct kinematic problem of the testing bed. According to the structure of the3-RPR planar parallel manipulator, the rod length approximation method is used to solve the direct kinematic problem of the test bed. Besides, the parametric descriptions and mathematic formulations of super-maneuver stunts which aircrafts perform were studied; the mathematic model that reflects the relation of parametric descriptions of the aircraft and joints variables of the model support system was established and verified the model with examples of calculation.Then to deal with the singularity which probably occurs in the structure of the wind tunnel testing, singularity analysis of it was put forward with the Jacobian method and the line geometry method, and verify the conclusions each other which are given by the two methods.Finally, according to structural constrains related to the wind tunnel testing bed, based on the solution of inverse kinematics, using MATLAB mathematic software, the paper has completed the workspace of different parameters with the extreme boundary search method. Furthermore, the analysis of the influencing factors impacting on the working space of visual analysis has been done, and got what factors affecting the workspace are major factors.