Welding Robot Fault Tree Analysis

The Welding robot is an electro-mechanical system,whose motion mode is previously determined by programs.More than 50%industrial welding robots are applied in various welding fields.Industrial welding robot technologies are widely used in such fields as automobiles,aerospace,and ships.Various unknown factors in the welding process have effects on welding process,so it is essential to improve the reliability of robot.Therefore,the fault analysis of welding robot is quite meaningful.The main wok of this paper is listed as follows:(1)This paper strictly adopts the fault tree analysis method to present the reasons and forms of industrial welding robot faults,and analyzes factors causing system faults.Failure types and correlation of different parts in the system are found out by using deductive analysis method.In addition,this paper analyzes failure modes of welding robot and build detailed overall fault tree.(2)Combining with the fault tree built in the paper,qualitative analysis of overall system,subsystems such as body system,control system,welding system and driving system of welding robot is conducted in detail,whose method is FTA,thus getting minimum faulty unit,namely minimal cut set,which has caused feed system faults.(3)Based on the fault tree built before and qualitative analysis,this paper carries out the quantitative analysis of the system,mainly event importance analysis.In addition,this paper calculates the importance of various minimal cut sets,and acquires key basic events and weak links causing system faults.On this basis,this paper comes up with some modification suggestions,and some feasible methods to improve the reliability of the whole system.Above all,through the construction,qualitative analysis and quantitative analysis of the welding robot fault tree,this paper points out the weak link of each subsystem,and makes contributions to improving the reliability of welding robots.