Research In Design Method Of Delta Mechaniam And 2-DOF PPM

This paper is based on the theory of the physical model of the solution space. Studying the research method of parallel mechanisms in the world deeply in the first step, Researching the design method of the improving Delta mechanism and 2-DOF parallel planar mechanism, and draw the performance atlases by computer aiding, So we can get some help on designing mechanism from these work. First of all, this paper set up the physical model of the two mechanisms, and draw the types of planar closed configurations by using change point mechanism line, discuss the characters and disciplines of the component size in every closed configurations and draw the figures of these types. Second, using the geometry method and vector transfer method solve the direct kinematics problems of the two mechanisms respectively. Using size restriction method solve reverse kinematics problems. Getting the expression fit for analysis and calculation. This paper analyze the workspace of the two mechanisms, and show the figure by plotting tools, discuss the workspace performance index, and draw the workspace atlas, discuss the relationship between size parameter and workspace index by analyzing the atlas. Using derivative method found the Jacobian of the two mechanisms. Then found the maths model according to the definition of kinematics transmission isotropic indices, denote the relationship of isotropic indices and size parameter by using the distributions of the kinematics transmission isotropic indices. Choose appropriate size parameter by the atlas. Defining the bottom velocity extremum based on the kinematics analysis, and combining with physical model, draw the bottom velocity extremum performance atlas, then analyze the influence of size parameter to the bottom velocity extremum performance indices. This paper offer an all-pervading method in designing mechanisms through analysis of the two mechanisms, and discuss the relationship of important performance indices and size parameter. This conclusion will be considered as the reference to designing.