No abstract

To reduce the downtime and optimize the use of energy and manpower, a serial - parallel manipulator is designed for transferring heavy billets for a specific hot extrusion forging process. To increase the structural rigidity and restrict the end-effector of the robot moving in direction parallel with the ground surface, parallel links are added in between serial links of the manipulator design. This modification of the structure must be considered in the modeling and analyzing. This paper addresses the kinematic modeling, the kinematic performance analysis and the strength analysis for the robot. With respect to the parallel links, the constraint equation is written and put together with the kinematic model. Based on the model formulated, the inverse kinematic, the transferring time, the reachable workspace, the dexterity, and the manipulability index of the robot are analyzed and discussed to demonstrate its kinematical performance. These results are important to assess the working capability and improve the parametric design for the robot. In addition, for verifying the end-effector design in terms of the strength and displacement, the stress distribution and the static deflection of the end-effector module are computed and analyzed by using the computer-aided finite element method (FEM).

The trend of scientific development in the future cannot fail to mention the great influence of the space field, but in the immediate future, the observational satellite systems are related to communication technology. In fact, in some countries with strong development of communication technology and space technology, the mechanical system of geostationary satellite monitoring antennas has certainly been thoroughly resolved. However, because of a specific technology, the sharing and transferring of design and manufacturing technology to developing countries is a great challenge. It is almost difficult to find published works related to mechanical design calculation and manufacture of geostationary satellite monitoring antenna systems. The problem of proactive grasping of technology, step by step autonomy in manufacturing technology of telecommunications equipment related to space technology has always been the goal of developing countries like Vietnam to limit technology dependence, minimizing technology transfer costs, ensuring national security. The first step in these problems is the autonomous construction of terrestrial transceivers such as geostationary satellite monitoring antennas. This paper presents the kinematics modeling analysis of the mechanical system of the geostationary satellite monitoring antenna. Each component of the antenna system is assumed a rigid body. The mathematical model is built based on multi-bodies kinematics and dynamics theory. The DENAVIT-HARTENBERG (D-H) homogeneous matrix method was used to construct the kinematics equations. The forward kinematics problem is analyzed to determine the position, velocity, acceleration, and workspace of the antenna system with given system motion limits. The inverse kinematics problem is mentioned to determine the kinematics behaviors of the antenna system with a given motion path in the workspace. The numerical simulation results kinematics were successfully applied in practice, especially for dynamics and control system analysis of geostationary satellite antenna systems.