Synthesis And Characteristic Research On The 3-DOF Parallel Manipulator With One Passive LEG

With the development of parallel robot research, lower-mobility parallel robots have attracted much attention due to their simple in structure, easy control, and low cost. The lower-mobility parallel robots are the new and the focus in this field and have very vast application vistas in industry. Based on the analyses of the current situation of the lower-mobility parallel robots home and abroad, this dissertation focuses on the characteristics of 3-DOF parallel manipulators with one passive leg by using analytic approach and computer aided geometry approach. The research is financed by National PHD Foundation.At first, by using the geometric constraint, the dimension constraint, the dimension equation and the dimension driving techniques of CAD, fifteen 3-DOF parallel manipulators with one passive leg are created. Secondly, the position,velocity and acceleration of 3-DOF parallel manipulators with one passive leg 3-SPS/UP,3-SPS/PU,3-SPS/RPR are studied by analytic approach and the static force of parallel manipulator 3-SPS/UP is analyzed by using virtual work theory. Finally, based on the construction of the position simulation mechanism, the position of spatial parallel mechanism is analyzed; create the velocity–acceleration simulation mechanism with three position simulation mechanisms at different time in the same sketch, and add dimension constraint equations to make three positions coincided, and then the velocity and acceleration of spatial parallel mechanisms are solved; the spatial curves are constructed when the active legs are given by extremum, and the curves create boundary surfaces by using the surface loft command, and then the workspace of mechanism is constructed .The computer aided geometry approach solves the inverse solution of the position,velocity and acceleration of the spatial parallel manipulators and proves the results comparison with theanalytic approach results.The research work of this dissertation establishes theoretical basis for the further research of the 3-DOF parallel manipulator with one passive leg practically.