Industrial Robot Kinematics And Reliability Research

In today's era of high labor costs and automated production,the application and promotion of robots and technological improvement have attracted much attention.With the increasing demand for production efficiency and product quality in manufacturing industry,the positioning accuracy and reliability of industrial robots have become the focus of attention of scholars at home and abroad.In engineering practice,due to the existence of machining error and assembly error,there are usually deviations between connecting rod size and design value of industrial robots,gap between joints,and backlash between gears of transmission devices.Influenced by these uncertainties,when an industrial robot wants to reach a certain location point in space or move along a certain trajectory,it usually shows some problems,such as the deviation between the actual location point and the ideal value,the fluctuation between the actual trajectory and the ideal trajectory,and so on.When the situation is serious,it will lead to the failure of the industrial robot positioning.In this paper,kinematics and reliability of industrial robots are studied.Firstly,in order to control the trajectory of industrial robots in the workspace and achieve the established tasks,it is necessary to know the position and attitude of the robots at any time.The determination of working position and attitude is the basic problem in the kinematics research of robots.Homogeneous coordinate transformation is introduced to derive the coordinate transformation equation.In this paper,the D-H parameter method is used to solve the parameters of translation and rotation coordinate transformation between two coordinate systems,and then the kinematics model of the robot is established,and the pose of the robot is analyzed.Secondly,the solution of the inverse motion of the robot is also a very important part of the kinematics of the robot.At present,there is no general solution to the inverse motion of the robot.In this paper,the screw theory and Paden-Kahan sub-problem are used to derive and solve the inverse solution of a special six-degree-of-freedom robot.Then,the inverse solution of a six-degree-of-freedom robot is derived by D-H method.An example shows that the inverse solution of a six-degree-of-freedom robot can be obtained correctly by this method.The accuracy of the inverse solution and the stability of the robot joint motion are compared between the inverse solution algorithm based on screw theory and the inverse solution algorithm based on D-H method.Finally,considering the uncertainty of joint clearance and link size deviation,the maximum entropy method in probability is used to study the failure probability of robots.In this paper,the fourth-order moment estimation method based on maximum entropy principle is used to calculate the reliability of robots.Compared with the traditional first-order second-moment estimation method and Monte Carlo simulation,the results show that the maximum entropy method can improve the accuracy of calculating the failure probability.In the process of analysis,the integral intervals of some functions in the maximum entropy principle need to be truncated.In the selection of the truncated intervals,this paper considers the deviation between the fourth moment estimation method of the maximum entropy principle and the Monte Carlo method as the objective to find the truncated intervals satisfying the accuracy requirements.