Research Of Robotic Technology On Plasma ARC Surface Hardening

In order to ensure the stability of the mechanical system operation, extend the servicelife of mechanical products, and reduce the failure of parts surface, metal surfacehardening technology can not only improve the strength of the material surface, abrasionresistance and fatigue resistance, but also give full play to the performance of the material,reduce the consumption of high-quality material and cost of production. In recent years,Plasma Arc surface hardening technology as a rising star in Metal surface hardeningtechnology has been used widely. Plasma arc surface quenching is a surface heat treatmentmethod for the material using a heat source of high energy density. Due to the quenchingeffect is excellent, the method develops rapidly. In order to match the development of theplasma arc quenching technology and extend the quenching field, it is necessary tocombine plasma arc surface enhancing technology with robotics technology.Robotics technology is one of the developing rapidly technologies in recent years.Through the study of series-parallel robot, the author found parallel robot can not onlymeet some requirements for workspace in the process of strengthening parts, but also havegood dynamic performance. It is suitable as a plasma hard iron driven equipment.Meanwhile, serial robot can make up the shortcomings of parallel robot, forming acomplementary relationship. The study of series-parallel gets the attention of a largenumber of scholars.The main contents of this paper include:1) analysis of structural characteristics andquenching applications of plasma equipment and plasma arc, specific elaboration of thefeatures of plasma arc surface quenching. In addition, comparing to the other quenchingcharacteristics, the author summers up advantages of the plasma arc surface quenching.The detailed analysis of the plasma arc surface quenching process performancerequirements provides a prerequisite for the design of the robot. Meanwhile, the authorsummarizes the development needs and robotics applications, analyzes the advantages ofseries-parallel robots, to determine the matching robot model of plasma arc surface quenching.2) The author makes an in-depth study for a key part of robot which is3degrees offreedom parallel robot mechanism; analysis and comparison of the characteristics of thetraditional mechanism3-RPS,3-SPR,3-PSR and3-RRR; according to advantages of fewerdegrees of freedom asymmetric parallel mechanism, designs the new robot structure.3) The thesis includes kinematics analysis for the parallel mechanism (the key parts)of the robot, introduction of asymmetric3-RPS parallel robot structure, analysis for itsposition, analysis for the method of determining the position and orientation of theplatform, establishment of inverse position equation, the location of the inverse of thespecific expression, the consideration of the constraints of3-RPS parallel mechanism. Theauthor using the boundary search method depicts the asymmetric3-RPS robot workspace.Through the analysis of the working space, the robot can be determined to meet thequenching of the coordinate complex surface gears. At the same time, it provides atheoretical basis for plasma arc surface quenching.4）The article studied the velocity and the acceleration solving method of asymmetric3-RPS parallel robot, and applied this method to analysis displacement, velocity,acceleration of the robot, analyzed the movement character of the institution, also analyzedthe feasibility of the institution from another angle, providing technical support for controltheory.