The Reserch Of Elastic Deformation And Stiffness Of Two Six-dof Parallel Manipulators With Planner Limbs

In the field of morden parallel mechanism, In terms of relative to its own less degree of parallel mechanism, six degrees of freedom parallel mechanism has some advantages, such as a big stiffness, low inertia, more compact structure, not easy to produce deformation, etc. So more and more experts and scholars focus on six degrees of freedom parallel mechanism, scope of application is becoming more and more big. because the closed loop structure is proposed, its structure becomes more simple and closely, at the same time, the rigidity and flexibility of mechanism is also improved.In this paper, two kinds of 6 dof parallel mechanism as the research object, planar branch institutions relative to the base of the different methods of movement caused the differences between two institutions in structure, therefore led to them working in space, the rigidity and the different application occasions. In order to further understand the performance of the agency, to the two agencies, the author of this paper has carried on the research of elastic deformation and stiffness, mainly includes the following content:First, build institutions of simulation wireframe and solid model, calculate the speed of two parallel mechanism and force jacobian matrix.Second, to solve the position inverse solution, the driving force of the institutions and the elastic deformation of driving rod, considering the plane branch under the premise of upper and lower beam deformation, to solve the agency branch stiffness matrix, Combined with the virtual work principle and the Jacobi matrix to solve the agency of the whole stiffness matrix, then calculate the center of moving platform deformation.Last, agency for the finite element simulation and analysis, it is concluded that the organization moving platform center deformation simulation values and compared it with the theoretical value. In addition, in order to avoid institutions work in resonance phenomenon and harmful vibration mode, the modal analysis was carried out on the two kinds of mechanism, its natural frequency are obtained.