Reliability Prediction Method And Its Applications

Modern science and technology are widely developed recently,robotics technology has been unrivalled robust development,robots are widely used in various fields of industries.Due to the gradual decline of the comprehensive performance of the robot in the use process,its reliability and stability cannot be guaranteed,resulting in some uncertainties in the use process,so its wide application is facing a severe test.The first objective set at the beginning of my thesis is to understand the context theory of reliability prediction as well as the methods used to prove the effectiveness of the methodology adopted.We present in detail the characteristics of the weak links having a direct effect on the evaluation for reliability or robot system.After that,review the main methods of evaluating reliability prediction.Three types of reliability assessment methods are presented,the failure mode and effect analysis,fault tree analysis and the probability density function.After a literature review,the definition and use of the reliability theory and the design of the experiment take its part which leads us to choose the reliability methods adapted with the robot system.Next,we present essential methods for estimating reliability prediction by testing in the development cycle the robot system.Then,applied the failure mode and effect analysis to study the risk priority number of a different part of the robot system.Come after,fault tree analysis which is a logical tree representing the combinations of elementary events that conduct to the realization of an event considered undesirable and get the weak links between different components and combinations of the robot system.The last part of this work was the experiment carried out and the data result used to study the reliability of manipulator by getting probability density function and its parameters.During the working process of the robot system,the graspforce and rail have a major effect on the reliability of the robot system.This two-parameter has been analysed based on probability density function and the useful three common distributions in reliability fields: Normal,Gamma and Weibull distributions,the exponential distribution has been applied to get the reliability function of the pneumatic system of the robot.