Chunxiang Ma

Application of a novel 6-DOF parallel robot with redundant actuation for earthquake simulation

In this paper a novel orthogonal 6-DOF (Degree Of Freedom) parallel robot with redundant actuation is studied as an earthquake motion simulator. Taking the practical simulation of earthquake waves into consideration, we firstly analyze the general characteristics of natural earthquakes. Complexity and variety of seismic waves, 3-dimension and multi-DOF movement and strong devastating force are regarded as their three obvious features in this article. Based on the characteristics of this novel orthogonal 6-DOF parallel mechanism with redundant actuation and the features of earthquakes, the feasibility of using this parallel robot as an earthquake motion simulator is analyzed. In order to simulate earthquake motion by using the parallel robot, its unambiguous kinematics and dynamics models are derived in details. The control system of the proposed earthquake simulator is developed based on the PXIbus development platform. A typical three-direction earthquake motion, the El Centro earthquake, is simulated on the end-effector of the parallel robot using its mathematical models and control system. Three main motion parameters of simulated seismic waves, displacements, velocities and accelerations are measured respectively. The experimental results show that this equipment is appropriate for using as an earthquake simulator.

Design and research of a novel type of mechanical presses driven by three servo motors in parallel

A novel type of mechanical presses design driven by three servo motors in parallel is proposed to develop high stamping capacity based on the theory of generalized function sets, and then is improved to enhance its practicability in engineering practice. The inverse and forward kinematics analyses are conducted later. Based on the fuzzy probability theory, the computing method of fuzzy reliability of kinematic accuracy of slider is then obtained. Finally, with a set of optimized length parameters of the presses given, the fuzzy reliability is calculated, on the basis of which a typical deep-drawing process is simulated.

Study on the Offshore Wind Turbine Installation Equipment With 6 Sets of Intelligent Legs

In this paper, a new type of the offshore wind turbine installation equipment is proposed, which has 6 sets of intelligent legs. Each intelligent leg consists of two-UPS and one-UP. Based on the theory of the parallel mechanism, the mechanism of this offshore wind turbine installation equipment with 6 sets of intelligent legs is constructed. We take a set of the intelligent leg for analysis and conducted kinematic analysis and dynamic analysis on the offshore wind turbine installation equipment. Finally, by studying the fuzzy reliability of the kinematic accuracy of a branch, the reliability model of the whole mechanism of the installation equipment combined with the characteristics of installation process is established, and the calculation of the fuzzy reliability of the kinematic accuracy of the whole mechanism is carried out.Copyright

Study on a New Kind of 6-Degree of Freedom Parallel Earthquake Simulator

In this paper, a kind of 6-degree of freedom parallel earthquake simulator is proposed, which has 28 -input, two types of the branches and the redundant and fault-tolerant actuators. Based on the theory of the parallel mechanism, the mechanism of the 6-degree of freedom parallel earthquake simulator with 28 -input and the redundant and fault-tolerant actuators is constructed. The kinematic model of the earthquake simulator is established by D-H method. The kinematic simulation and the dynamic simulation of the earthquake simulator are carried out with ADAMS software. Finally, FEM model of the earthquake simulator is given and the modal analysis of the earthquake simulator is made with ANSYS software.Copyright

Study on the New Type of the Positioner

In this paper, a new type of the positioner is proposed, which has with dual-drive and dual-screw. Comparing with the positioner of the traditional gear transmission system, the positioner with the new mechanism has less power and less work space. Based on the designing requirements, we optimized the dimensions of the mechanism of the positioner, and carried out the kinematic and dynamic analysis of the positioner. The strength and the rigidity of the positioner are analyzed by the use of FEM. Finally, according to fuzzy mathematical theory, the reliability of the mechanism motion of the positioner is studied.Copyright