Ji Man Luo

Modal Analysis of Mast Section of Hoist Based on the Vibration Theory

Vibration is one of problems of mechanical structures, because structural resonance or fatigue will be caused by the vibration, thus it will be cause the damage of structure. In order to avoid the damage of structure, it is necessary to analyze the stiffness characteristics of the structure，which is the natural frequency and vibration mode figure, therefore unnecessary loss because of the resonance causes can be effectively avoided. By using modal analysis method which is in the structural dynamics, vibration pattern of structure system can be visually obtained from theoretical calculation and ANSYS simulation. The first 6 order natural frequencies of different working conditions have been calculated in this paper, dynamic displacement formula in external excitation have been shown when the cage move to a different location. Vibration mode figure of structure system can be drawn corresponding to the first 6 order natural frequencies, based on the finite element analysis software ANSYS, vibration image of structure system have been simulated corresponding to the first 6 order natural frequencies. The dynamic characteristics of structure system are affected when the cage to a different location. Through the cage to a different location, external excitation force have a great influence on the top of the free end, in the actual construction, the top free ends connected tie-in device stiffness should be strengthened, the system stability will be improved.

A New Type of Parallel Robot Manipulator Kinematics Simulation and Analysis of Movement Characteristics

Kinematics simulation and characteristics of a new type of parallel robot manipulator (PRM) with two-dimension movement and one-dimension rotation are analyzed. The new PRM is proved to can realize expected movement, and have smooth movement curves of displacement and velocity. The moving platform center of the PRM can achieve a wide range of swing, and has a larger working space. According to the kinematics theory, the working space and singularity characteristic are analyzed. Simulation and analysis indicated that the working space of the new PRM in the form and position is not singular, and has good maneuverability, thus providing the foundation for practice application and product exploitation.

Research on a New Hybrid Robot Real-Time Testing System

To achieve real-time monitoring for new type of robot motion state, the testing software of robot motion characteristics is studied in this article, based on Linux system, using Qt software compiling. First of all, the new robot prototype and test hardware system are introduced; secondly, the real-time testing curve of displacement, velocity and acceleration are compiled by fitting of the measured data, on the Linux operating system platform, using Qt programming; finally, the testing software run, and its accuracy is verified by experiment.

Research on the Static Mechanics of the Hybrid Robot

The purpose of this research is to get the static mechanical distribution of the hybrid robot and provide the basis for its structural optimization. In this paper, the parallel manipulator which is suffered the maximum force of the robot is studied according to the statics analysis theory of space mechanism. The position distribution of extreme stress and extreme strain on the key components which is suffered the maximum driving force is obtained by the simulation of finite element analysis, then the strength of the existing structure is checked, laying the foundation for structural optimization.

Research on a New Robot Test System Design and Implementation

The design scheme of 3TPS / TP new robot test system design is described in this article, and Linux-based embedded system as the core is proposed, with displacement and tension sensor detecting robot motion and mechanical performance, the overall program is achieved by an interactive interface functions. The hardware design and software design framework is advanced, not only the high-precision performance of the hardware system is ensured, but also the multi-functional development of software is realized. Finally, experimental test is carried out, the detection of robot to its motion precision and the load characteristic is implemented, the experimental results verify the feasibility of the system solution.

Study on Error in Interpolation Algorithm of the-5-DOF-Hybrid Robot

In order to improve the accuracy of the-5-DOF-hybrid robot motion control, it is necessary to establish a mathematical model of the error in the interpolation process. On the basis of the structure characteristics of five degrees of freedom hybrid robot and the algorithm of linear interpolation and circular interpolation, the error calculation patterns about the concave surface machining and convex surface machining are set up respectively in the paper. Then, examples are analyzed. The results show that the nonlinear error caused by using the straight-line interpolation method is much smaller than the normal vector rotation error and linear approximation error; when conducting surface machining, the error caused by the application of circular interpolation algorithm is less than linear interpolation error. By the comparison of the error analysis of different interpolation method, the control methods for reducing errors are proposed.

Dynamics Simulation Study on 3-TPS/TP Parallel Robot

The purpose of this research work is to find the relationship between the movement and force (torque) of 3-TPS/TP parallel robot, the Lagrange method is adopted to establish the dynamics model, and the results of the simulation by ADAMS are given in this paper. The curve is about the change of force come from every joint of active chains with time. It provides a lot of data for further reference to choose the drive device.

Vibration Analysis and Simulation of Mast Section of Hoist

In order to avoid the damage of structure caused by the vibration, the natural frequency and vibration mode figure of the stiffness characteristics of the hoist’s structure should be analyzed. Modal analysis method is presented for solving above problem, and the first 6 order natural frequencies in different working conditions have been calculated in this paper. Vibration mode figure of structure system have been simulated corresponding to the first 6 order natural frequencies based on ANSYS. It is shows that the external excitation force have a great influence on the top of the free end when the cage moves to a different location. So, in the actual construction, the stiffness of top free ends connected tie-in device should be strengthened, therefore the system stability will be improved.

Simulation of Dynamic Characteristic for Parallel Machine Tool

The dynamic characteristics of parallel 3-TPT machine tool are researched by simulation and experiment in this paper. Firstly, modal analysis principle of machine tool was analyzed in theory, and the parameters of dynamic characteristic were identified by theoretical analysis. Then vibration model of parallel machine tool was built in ADAMS and formed vibration system of rigid and flexible coupling for simulation analysis, and from the simulation results got the value of parameters for vibration characteristic of parallel machine tool. The simulation results showed that the simulation method and result dates are validated, which provides reference for dynamic optimal design.

Dynamic Characteristics of Guideway Joints for CNC Machine Tool

In order to analyze accurately the dynamic characteristics of guideway joints of CNC, the finite element model(FEM) of guideway joints of CNC is built in ANASYS software, which that springs and damping units imitate guideway joints in this paper. The proposed method can predict the regular pattern which joint stiffness and joint span affect natural frequency and harmonic response. The research demonstrates that the method predicts well the dynamic characteristics of the guideway joints of CNC; therefore, it can be a reference for dynamic optimization design of guideway joints of CNC machine tool.