# Simulation-Based Reliability Design Optimization Method for Industrial Robot Structural Design
###### Abstract
[13; 14] optimized the performance of a six-axis industrial robot on the basis of stress, modal, and vibration analyses by using FEM of the ANSYS workbench. [PERSON] et al. [15] modified the design of the robotic arm based on the analysis of von Mises stress and strain by using ANSYS simulation. [PERSON] et al. [16] proposed an optimization framework to carry out a structural optimization design of a five-DOF welding robot considering the strength, stiffness, and robot weight by using ANSYS. The above-mentioned research on the structural optimization and simulation design of robots was completed with a deterministic analysis. However, there inevitably exist various uncertainties in actual engineering [17], for example, the variation of the coefficient related to a material's properties derived from the discreteness of engineering material properties [18], the variation of the dimensions related to manufacturing errors [19], etc. The deterministic design ignores the influence of uncertainties, which generally yields unreliable design results, especially in the optimization design. In the design of an industrial robot, uncertainties are also an important factor to be considered. [PERSON] et al. [20] proposed a dynamic and static structural topology optimization method with uncertain parameters for the lift arm of a parking robot. [PERSON] et al. [21] performed a trajectory optimization under non-probabilistic time-dependent reliability constraints to improve the soaring operating performance of robotic manipulators. [PERSON] et al. [22] realized the design optimization of clearance joints based on reliability sensitivity analysis. [PERSON] et al. [23] constructed the dynamic modeling of a one-link flexible manipulator using the stochastic finite element method in terms of the displacement of the manipulator's tip and the frequency response function subjected to uncertainties. [PERSON] et al. [24] also proposed a novel robust optimal design for parallel manipulators to optimize the performance indices subject to the unavoidable effect of the uncertainties. Currently, the design optimization of a robot considering the uncertainties is mainly focused on the joints design and the trajectory optimization. As for the structural design of a robot, it is mainly performed by the deterministic design optimization. Through the above analysis, the reliability design optimization for a robot is very important for improving the reliability of an industrial robot structural design. Moreover, improving the calculation efficiency of the method can effectively promote the application of the method in engineering. Therefore, in this paper, a simulation-based reliability design optimization method (SBRDOM) is prosed for an industrial robot structural design. In the proposed method, the simulation design is integrated with the reliability design optimization to obtain a robot structural design model, and therefore, the best balance between economy and safety could be achieved during the robot structural design. Furthermore, the SORA algorithm was employed to solve the problem of low computational efficiency of reliability design optimization in engineering applications. The remainder of this paper is organized as follows. Section 2 provides the proposed SBRDOM, including the SBRDOM procedure, the formulation of the reliability design optimization model and the SORA algorithm and its associated mathematical formulation. In Section 3, the design of the big arm and small arm is used to demonstrate the validity of the proposed method. Finally, Section 4 concludes this work and suggests future work.