Research On The Kinematics Analysis Of Industrial Robots And The Modeling Methods Of High-dimensional Surrogate Models

Under the background of China's economic transformation and industrial upgrading,industrial robots have become more and more widely used in industry and manufacturing.The positioning accuracy of the robot is an important indicator reflecting the performance of the industrial robot.The positioning accuracy includes two kinds of absolute positioning accuracy and repeated positioning accuracy.Although industrial robots usually have a high repeat positioning accuracy,its absolute positioning accuracy is still far from meeting the high precision requirements of precision machining,aerospace assembly and other industries.In engineering practice,due to the existence of processing errors and assembly errors,the difference between the actual kinematics parameter value and the nominal value of the robot will inevitably produce positioning errors,so the research on the absolute positioning accuracy of industrial robots Certain theoretical guiding significance and practical engineering application value.This article takes KR150-2 industrial robot as the research object,and mainly completes the following work:(1)Explain the theoretical basis of industrial robot kinematics,introduce the classic robot kinematics analysis model: D-H model,establish each link coordinate system of the robot,and express the displacement and sum between two adjacent link coordinate systems through a homogeneous coordinate transformation matrix The amount of rotation changes,and then derive the expressions of the robot kinematics forward and inverse solutions.(2)Establish a three-dimensional solid model and a motion simulation model of the KR150-2 industrial robot,set a drive motor to drive each joint to rotate at a uniform angle with time,and study the mechanical properties of the robot's connecting rod joints during a period of planned trajectory movement.(3)The technical method of the agency model is described.In view of the problem that the number of sample points required for modeling in the traditional agency model will increase exponentially with the increase of the problem dimension,an i Kriging-HDMR method is proposed.This method is based on the Kriging model and the high-dimensional proxy model(HDMR),and uses the DIRECT sampling method.By improving the initial sample point selection and model optimization iteration convergence conditions,the proposed proxy model has higher global accuracy when solving high-dimensional problems.And computational efficiency.Finally,the model evaluation results of 4 numerical examples verify the effectiveness of this method.(4)Using the i Kriging-HDMR modeling method and the method of pre-given kinematics parameter errors,the kinematics agent model of the KR150-2 industrial robot is established and 16 D-H parameters are introduced as error factors.The sensitivity of factors such as the length of the connecting rod to the accuracy of the end,the specific error value caused by each factor to the accuracy of the end is solved.