Research On Vibration Elimination Of Spot Welding Robot With High Load

This paper comes from the national high tech research and development plan(863 plan)advanced manufacturing technology field"new welding and other industrial robot project",the main goal is to have developed a 165 kg spot welding robot in the car spot welding process,through analysis,find out the cause of vibration,and study the method to reduce or eliminate the bad vibration,in order to improve the efficiency of domestic spot welding robot.Spot welding robot is one of the two main industrial robots used in the process of car production.No spot welding robot,there is no modern automotive industry.Firstly by the method of vibration experiment on the support point of the welding robot vibration characteristics were studied ten mode formation and natural frequency is obtained,and puts forward the suggestions on the robot arm,a machine base according to the mode.Large arm vibration type is more complex,need special research and improvement.Then the experimental study on the performance of the front three joints of the large key welding robot is carried out.The speed servo performance of the robot is not good enough.To this end,it is recommended to increase the active vibration suppression function.Experimental results show that the robot controller is still using the trapezoidal velocity curve.The advantages and disadvantages of the trapezoidal velocity curve are analyzed.The main advantage is that it is easy to calculate,but there is a prominent shortcoming,that is,there is a rigid impact at the start and stop of the first two points,it is easy to cause the vibration of the large key welding robot.In order to improve the paper,2 kinds of modified curves of polynomial and trigonometric function are derived,which have no rigid impact and will not cause the vibration of the robot.In order to improve the arm of the robot,the paper summarized the literature data about the vibration of the robot,and summed up the two methods to solve the problem of robot vibration,and put forward a structure optimization method based on TOSCA and ADAMS software.Under the condition that the company given the rigidity,the structure is optimized,and a new large arm structure is obtained,which effectively reduces the large arm quality,and can reduce the harm caused by the bad vibration of large key welding robot.At the end of the paper,the research work is summarized and the future work is prospected.