Research On Kinematics Of A 3-dof Parallel Robot And Development Of Its Prototype

As an important measure of the level of a country’s scientific and technological innovation and high-tech manufacturing, robotics intelligence attentions more and more countries. Parallel robot, with the advantages of stiffness, strong bearing capacity, small error accumulation, has been widely applied to various areas of society. In this paper, a kind of 3-dof parallel robot is studied.The prototype of the parallel robot is designed based on the study of its kinematics, laying the foundation for industrial applications.Firstly, the mechanical structure and working principle of the parallel robot are analyzed and the degree of freedom for the parallel robot is calculated. Then this paper studies the kinematic of parallel robot according to the geometric constraints and analyzes the relationship of position, velocity and acceleration between the moving platform and driving sliders. The kinematic equations are solved, laying the foundation for the motion control of the robot. Then the workspace of the 3-dof parallel robot’s moving platform is solved with the method of boundary-searching in cartesian coordinate space. The views in different directions of the workspace are showed by matlab.Secondly, the organizational structure of parallel robot’s system is determined according to its performance. The parallel robot’s system consists of PC, motion controller, motor, motor driver, limit switches and the mechanical structure. Then designs each part of the robot’s system specifically. Assemble all the components to form the hardware platform of the parallel robot.Thirdly, based on the parallel robot’s hardware platform, this paper designs the controlling software. According to the features of UCOS operating system, determines the architecture of the system-control software. Then designs the detailed programs of serial communication module, motor control module and platform-positioning module.Finally, this paper studies the trajectory planning methods of the parallel robot. Two interpolation methods commonly used in joint space are comparatively studied. Then do trajectory planning experiments with the prototype to test and verify the feasibility of the selected trajectory planning method.