Several Kinds Of SPR And RPS Brance 3 Degree-Of-Freedom Parallel Manipulators Characteristic Research

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 SPR and RPS brance by using analytic approach and computer aided geometry approach.(1)Based on the CAD geometry restraint, the size restraint, the size equation and the size actuation technology constructs sevaral three degree-of-freedom parallel manipulators of SPR and RPS brance.(2)With analytic approach to 2SPR+RPSⅠ, 2SPR+ RPSⅡ, 2SPR+ RPSⅢ,Three kind of parallel manipulators carry on the position analysis, the velocity analysis and the acceleration analysis and the static force of parallel manipulator 2SPR+RPSⅠis analyzed by using virtual work theory.(3)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 the analytic approach results.(4) Contrast three kind of organization's working space, the speed, the acceleration, summarize their organization characteristic aspect good and bad points, and analyzes to the movement vice-arrangement's change to the organization characteristic influence.The research work of this dissertation establishes theoretical basis for the further research of the 3-DOF parallel manipulator with one passive leg practically.