Papers by Author: Chang Li

Abstract: The open arc welding robots have been used widely nowadays; however, the elastic deformations of every inner link inevitably affect the welding quality. In this paper, it proposes an effective method of service reliability assessment for the rigidity-flexibility coupling open arc welding robot. Firstly, a parametric virtual model of the robot is built in ADAMS/View-AutoFlex module. Secondly, the stochastic errors generated in the working process are simulated by a program created from pseudo-random numbers which have been written by multiplicative congruence method. Lastly, Monte Carlo sampling calculation is implemented for the virtual model, and large sample data of the dynamic characteristics in welding process are obtained and used to calculate the service reliability of the welding robot. This method includes simplicity (no need to solve complex mathematic model) and high accuracy which make it highly promising for application in mechanism design.

Abstract: In this paper, we report an effective method for motion reliability analysis of the PUMA560 series mechanism. It firstly builds a Monte Carlo parameterized 3-D virtual model of this mechanism in ADAMS, and uses VC++ to program a pseudo-random number subroutine function that conforms to normal distribution and user defining function to simulate the stochastic error distribution of the mechanism, and a universal reliability analysis program of the PUMA560 series mechanism is then developed. After multiple virtual tests on this parameterized mechanism model, a large mount of test data are obtained and statistically analyzed to calculate the motion reliability; this can evaluate the influence of different stochastic errors on the mechanism dynamic characteristics. The advantages of this new method include simplicity (no need to solve complex mathematic model) and high accuracy which make it highly promising for application in mechanism design.

Abstract: In this paper, it proposes an effective method for 6-6 Stewart parallel mechanism dynamics analysis in ADAMS. Firstly, it builds a virtual model in ADAMS/View, using spline function and self-defining function to define loads and constraints, through the follow-up dynamic simulation, the positive solutions and inverse solutions are solved conveniently, and this can provide a foundation for analyzing the parallel mechanism’s operability and space path line. Secondly, it uses secondary developing technology (APDL) to program a parameterized virtual model, which can give a credibility way to analyze the influence of random errors on the mechanism mobile. In short, it needn’t to calculate complex mathematic model as that in the past, yet this new method proposed provides a definite theory foundation and contains well application values for further study.