The Design Of Operation Arms For The Space Complex Surface Repair Robot And Applied Research

In the process of operation,the hydraulic turbine is often affected by the impurities in the water flow,resulting in different degrees of cavitation corrosion and wear of the turbine blades,which seriously reduces the power generation efficiency.After a certain work cycle,the hydraulic turbine will be down for maintenance that maintenance cycle of large-scale units need about 4~5 years,and each overhaul life took about 4 months that actually impact the generation time of hydraulic turbine.The turbine blades repair process in China is still using manual operation.Not only the efficiency is low,but also the operation in the narrow space of the poor working environment pose a threat to the health of workers.In addition,the shape of the blades of the turbine polished artificially is difficult to match with the original design shape,which changes the original flow state of the turbine and reduces the power of the turbine.Therefore,the high efficiency and quality repair operation of the damaged turbine blades has become a practical problem to be solved.In this topic,based on a thorough understanding of the turbine runner,blade structure and comparative analysis of the existing hydraulic turbine repair robots at home and abroad,we designed a space complex surface repair robot virtual prototype based on the mobile platform.The device can repair the damaged hydraulic turbine blades directly on the machine pit without the turbine hanged out from the machine pit and transferred to the maintenance shop,so the maintenance work has the advantages of safe,efficient,convenient,low energy consumption and so on.Firstly,according to characteristics of the relatively narrow space inside the machine pit,as the main part of the repair robot,operating arm was overall layout planned and the joints driven was under study.By the integration of modeling and simulation analysis software Solidworks to build a virtual robot model,we complete the main components general assembly in the virtual modeling.What's more,modal vibration research can be done by the Simulation finite-element analysis system.Secondly,through the D-H kinematics theory establishing kinematics model,the repair robot forward kinematics calculation was made that we could know the position and posture relationship between the terminal coordinate system and the base coordinate system clearly.Then the forward kinematics calculation was investigated and verified by MATALB Robotics Toolbox.The inverse kinematics calculation of the repair robot proved that it could complete the repair work,even though in the condition a joint failure to run.For another,the applied research of the repair robot is done mainly by kinematical simulation according to the welding and grinding path trajectory planned in advance.Based on the difference ofhydraulic turbine blades welded and grinded processes,the applied research of robot virtual prototype about welding and grinding processes was done respectively by ADAMS simulation software.Finally,the welding and the grinding operation system frameworks were constructed respectively.According to the different repair process,the application and selection of sensors in practical work was analyzed.What's more,the best welding source and parameters was experimental studied in order to prepare for the application and development of the robot physical prototype.