Theoretical And Experimental Analysis Of The Rigidity Of Stereoscopic Stone Carving Robot System On Machining Error

In the stone industry,stone carving is the perfect application of carving art in stone products,recording the development of world civilization from ancient times to the present.It is the main carrier of human culture and artistic heritage,and has high artistic and cultural value.stereoscopic stone carving is characterized by its complex overall shape and contour structure,numerous curved surfaces,and large dimensions.It has become the stone carving product that best embodies aesthetic concepts,artistic thinking,and technical difficulty.Using an industrial six-axis robot to realize stereoscopic stone carving can greatly save manpower,improve processing efficiency,and reduce the harm to human health caused by dust in traditional stone carving.Compared with traditional stone carving CNC machine tools,robotic stone carving has incomparable advantages in processing scope and flexibility.Because of this,robotic stone carving has become an important development direction for the transformation and upgrading of the traditional stone carving industry.However,the machining errors caused by the weak rigidity of the tandem robot accumulate,the machining accuracy deteriorates,the end tool deforms,and in severe cases,the tool can be broken and damaged.Aiming at the rough machining process of robot stone carving,this paper analyzes the causes of machining errors caused by insufficient robot stiffness,and studies its compensation.The main research work and important conclusions are as follows:1.This article takes the KUKA KR240-2900 model robot as the research object,and uses the improved DH parameter method to construct the link coordinate system of this robot.The kinematics model of the robot is established through the pose conversion equation.The forward and inverse kinematics were solved,and the Jacobian matrix of the robot was calculated by differential transformation.2.The static stiffness model of the robot was established,and the joint stiffness identification experiment system was established with the help of the laser tracker.The joint stiffness of the KUKA KR240-2900 stereoscopic stone carving robotprocessing system was obtained through multiple experiments.Finally,the theoretical analysis and experimental results were compared to verify The accuracy of joint stiffness.3.A machining force model and a machining error model for the robot are established,and the end deformation of different machining positions is simulated and calculated based on the different Cartesian stiffness of the robot's spatial position.Finally,the accuracy of the machining error model is verified by machining experiments.4.Based on the mirror-symmetric compensation method,the processing error of the rough machining of the robot stone carving is solved,and the corresponding robot cutting depth compensation solver software is developed.The results of cutting test show that the use of this method of machining error compensation in the rough machining of stereoscopic robotic stone carving can effectively reduce the processing error,make the actual cutting depth meet the set cutting depth requirement,and improve the machining accuracy of stone carving workpieces.The research in this paper has important guiding significance for improving the machining accuracy in robotic stone carving and promoting the application of robots in stone carving.