3T1R Of Parallel Mechanism System Design

Since the six DOF of the parallel mechanism in Stewart is launched in 1978, the research of parallel mechanism has become a important event for the many scientific researcher and teachers, and the most of students of study in the universities. Compared with serial robots, and this mechanism with its high stiffness, strong carrying capacity, high speed, precision accurate,and many other advantages has been the larger development in recent decades. And it applied in many fields which including industry, the main science and so on successfully.Parallel mechanism is a new branch of study in advanced spatial closed loop mechanism,considering the six DOF of the parallel mechanism with the influence of factors such as hinge constraint, the singular configuration, the branch chain, leads to the difficulty of the all-round implementation of space posture movement, and it also can increase the complexity of this mechanism structure and the control state for the institution itself. And less DOF of the parallel mechanism arises at the historic moment, and it may be the one of the disadvantages. Because it has the advantages that structure configuration is easy, driving method is very simple, working space is larger, low cost and so on. So it owns high value in research and practical development,and it become the subject of mechanism research point quickly.Regarding 4-UPU parallel mechanism as the research object, firstly this thesis adopts a spiral motion and force spiral in the theory of parallel mechanism to represent freedom and constraint respectively, and by using the reciprocal theorem, consisting of the DOF of analysis of 4-UPU parallel mechanism with less degrees of freedom, and calculate the DOF of organization.Secondly, it put forward configuration design of parallel mechanism system of a 3T1 R type system method based on the screw theory(i.e. the type synthesis), the synthesis of parallel mechanism is the most important link of the feasibility of the design of this mechanism, its judgments based on a spiral theory moving between spiral and spiral binding reciprocal product is zero relationship to construct a leg mechanism may exist, and then through the legs of permutations and combinations of institutions, and a number of institutions have different structures, deputy sports. And the feasibility and practicability of some configuration verification analysis is proofed.Then through the virtual mechanism method to derive one or two order influence coefficient matrix, based on the analysis of the mechanism and influence of speed and acceleration coefficient matrix. The precision of the method for solving the kinematics is proved by the analysis of examples of numerical.At last, it builds a model for system design of the structure itself through the thinking methods of mathematical, and through the P-roe 3D software to carry out the kinematics simulation.Then it was solved for the forward and inverse position solution algorithm, and finally it verifies the correctness of the algorithm, rationality through the numerical examples.