Reliability Analysis Of Industrial Robot Drives Considering Failure Dependence Factors

Industrial robots have complex structures and integrate knowledge from multiple disciplines,which can represent the level of intelligent manufacturing in a country.As the world's largest consumer market for industrial robot applications,in the field of high-end industrial robots,China's self-developed robots are far behind the western powers in many aspects,so that self-developed products only occupy a small market share.The development of industrial robot technology requires the comprehensive development of its components.Drive is one of the most important components of industrial robots,whose reliability freatly affects the performance and reliability of whole machine.This paper takes the electrical drive of industrial robot as the research object,and analyzes its static and time-dependent reliability.The main research contents are as follows:(1)The classification and structure of industrial robots and their electrical drives are described in detail.According to the structure and function of the electrical driver,it is divided into seven modules,the components of each module are analyzed,and the reliability block diagram of the driver is drawn.The failure modes and dailure causes of electrical drives are collected through literatures,and the failure mode,effects and criticality analysis method is uesd to determine the main failure modes of the drive.On the basic of failure analysis,the failure process,failure criterion and related environment factors of the main failure are further studied,and the performance functions of the drive under different main failure modes are established in combination with the physics of failure technology.(2)The relevant theory of Copula function is introduced,and the appropriate Copula function is selected to carry out the research on the static reliability analysis method under the multi-failure mode correlation of the drive.The deterministic parameters and random variable distribution information in the function function are comprehensively determined through literature and actual engineering research;the function function sample is obtained by sampling method;different types of Copula functions are used to describe the correlation between failure modes,and the static reliability of the drive is calculated.Compared with the computed results of numerical simulation method,the feasibility of the Copula-based method is verified.(3)Based on the established static reliability analysis method,the time-dependent characteristics of some parameters in the functional function of the driver are considered,and a time-dependent reliability analysis method based on time-dependent Copula function with variable parameters is proposed.Using the proposed approach,timedependent reliability of the driver is analyzed,and the result is compared with the computed result of umerical simulation method to validate the feasibility of the proposed method.