Continuous Rotation Axes Study Of Some Parallel Mechanisms Based On Linegeometry And Screw Theory

Parallel mechanisms with continuous rotation axes have the advantage of easier calibration,simpler trajectory plan than usual parallel mechanism.It can also fulfill the trajectory that usual low-mobility parallel mechanism can't fulfill.The study of parallel mechanism can promote the application of parallel mechanism and improve the equipment manufacture level of our country.The present determine method of continuous rotation axes of parallel mechanism can't applied broadly and need complex calculation,so the dissertation try to find a method which is easy and is suitable to most parallel mechanism.And study a parallel mechanism that has continuous rotation axes in order to provide reference to type synthesis of parallel mechanism with continuous rotation axes.The main content of the dissertation include the constraint and continuous rotation axes of parallel mechanism,the new determine method of continuous rotation axes,the continuous movement characteristic of a 3-RSR parallel mechanism,the kinematic of the 3-RSR parallel mechanism,etc.In chapter 1,the research status of parallel mechanism and the research status of continuous rotation axes were introduced.In chapter 2,some new prove methods on some theorems in screw theory and introduced some basis in line geometry were introduced.In chapter 3,a new,easy and intuitionistic method on the determination of continuous of parallel mechanism was introduced.Using the method,some existing parallel mechanisms with 3,4 and 5 DOF were studied.In chapter 4,the certification of continuous movement of the 3-RSR parallel mechanism based on the conclusion in chapter 2 and spatial analytic geometry was introduced.And the possible continuous rotation axes of other kinds of constraints were studied.In chapter 5,the kinematic of the 3-RSR parallel mechanism were studied,including the inverse kinematics,working space and the first order kinematic influence coefficient.In chapter 6,the certification of the continuous rotation of a new 3-UPU parallel mechanism was introduced,and the motion simulation of the continuous rotation of 3-RSR parallel mechanism was done.The innovation of the dissertation are that the relationship of constraints and rotation axes were studied in the aspect of line geometry,a new,easy and intuitionistic determination method of continuous rotation axes of parallel mechanism were proposed,the continuous rotation axes of 3-RSR parallel mechanism were proved using the conclusion in chapter 2 and spatial analytic geometry and the realistic working space of 3-RSR parallel mechanism were gotten.Studying the continuous rotation axes of parallel mechanism in a new attitude enriched the basic theory of parallel mechanism.A new,easy and intuitionistic continuous rotation axes determination method can promote the research of continuous rotation axes of parallel mechanism.Introducing spatial analytic geometry in the certification of continuous rotation can provide reference to the study of continuous rotation axes and the study of other aspects.