Strutucral Optimization Of A High-Speed Light Load Robot Base On Equivalent Static Load Method (ESLM)

When robot is in high-speed movement,which will produce large inertia force, lead to the deformation of the elastic components,thus impact the accuracy of positioning of the end point. Therefore, optimizing the construction of robot, it can not only lose its weight, but also can reduce the inertial impact and improve the accuracy of end point positioning. However, due to the high speed light load robot is mainly caused by the inertia force, the traditional structural optimization method’s also unable to deal with each others coupling component of inertial force. Based on the equivalent static load method (ESLM) can combine nonlinear flexible multi-body dynamics analysis with linear static structure optimization,to achieve the optimization of structural components under dynamic loads and to deal with the component characteristics of inertial force coupling. This paper aims to make dynamics analysis and optimization design of parts by taking a six DOF high speed light load welding robot of the Noel Bei company as an example, Its main content:Firstly,it establishes the D-H coordinate and kinematics equation of the robot and it solves the positive and the inverse kinematic solution of robot. And in the virtual prototype(Adams) the rigid body dynamics model is established, making a point movement of "S" type curve points at the end of the driving robot, and the normalization method is used to make the trajectory planning and determine the movement boundary conditions of robot.Then,establishing the rigid-flexible coupling model of this robot by using the analysis software Hyper-works MotionView module. Through the analysis of the rigid body model and rigid-flexible coupling model to solve the point at the end of the displacement curve comparison.lt proved the robot have certain influence to the flexible deformation on the positioning accuracy of robot.Finally,establishing the flexible multi-body dynamic model of this robot.Then carring on the finite element analysis to get the distribution of the stress of the robot, so defining the optimization objective function and constraint conditions. As well as using the method of equivalent static load on the robot for dynamic structure optimization, to achieve the light-weight design of the robot at the same time, the end of the execution end point of robot positioning accuracy is higher.Using two different ways of structural topology optimization comparison:One is to optimize together, the other is a single optimization and then to assemble analysis.The results show that using this two different ways to dynamic optimization of robots,the robot performance has certain enhancement.But considering optimization at the same time in the process of optimization, the optimization of load change influence each other between parts, lead to the optimization effect is better.In this Paper,On the basis of the multidisciplinary integrated and it presents a dynamic response of structure optimization method, the equivalent static load method, and applied to optimal design of the robot.The results from these demonstrations show that applying dynamic response optimization on robot structure using equivalent static load method is feasible and can get a better improved structure. It also can reduce the dependency of engineers’ experience and cut off the time of applying optimization.