A topology optimization method of robot lightweight design based on the finite element model of assembly and its applications

Abstract

<jats:p> Topology optimization is a widely used lightweight design method for structural design of the collaborative robot. In this article, a topology optimization method for the robot lightweight design is proposed based on finite element analysis of the assembly so as to get the minimized weight and to avoid the stress analysis distortion phenomenon that compared the conventional topology optimization method by adding equivalent confining forces at the analyzed part’s boundary. For this method, the stress and deformation of the robot’s parts are calculated based on the finite element analysis of the assembly model. Then, the structure of the parts is redesigned with the goal of minimized mass and the constraint of maximum displacement of the robot’s end by topology optimization. The proposed method has the advantages of a better lightweight effect compared with the conventional one, which is demonstrated by a simple two-linkage robot lightweight design. Finally, the method is applied on a 5 degree of freedom upper-limb exoskeleton robot for lightweight design. Results show that there is a 10.4% reduction of the mass compared with the conventional method. </jats:p>

A topology optimization method for collaborative robot lightweight design based on orthogonal experiment and its applications

“…Because the connected parts of some joints may be not parallel to each other when the robot is kept in the specific postures, the model of the 7 DOF ULPE robot was simplified as the cantilever model with two links, as shown in Figure 6. Meanwhile, by referring to the maximum end displacement of a robot in relevant literature, 6,26,27 the end displacement constraints could be calculated based on the mechanics of materials(formula( 4)), 28 and the results are listed in Table 6. In addition, the design region of the parts should be set, which is usually the region of the parts except for some connection features (hole, key, groove, etc.).…”

“…Safety can be increased by reducing the mass and inertia of robots because the harm of the collision between machine and human body 5 could be weakened when the mass and inertia of robots become smaller. Therefore, the lightweight design plays a significant role in improving the safety of robots, 6,7 which can be achieved using new lightweight materials or optimizing the structures of parts. [8][9][10] To reduce the mass of robots, many researchers employed new lightweight materials in their designs.…”

“…However, before the material removal, the stress distribution of the parts to be optimized needs to be achieved by finite element analysis (FEA) based on these conditions in topology optimization. 6 And these extreme working conditions in EWC-TO may be different from the actual ones as the motion of collaborative robots achieved by the angle variation of its multiple joints is complex. It will cause that the load boundary conditions of the parts deviate from the real maximum one, which would eventually affect the performance of the parts.…”

Selection of Loads in the Design and Optimization of Manipulators of Portable Mobile Robots for Special Applications

“…W obliczeniach uwzględniono obciążenia wynikające ze zmiennej konfiguracji ramion, z rozdzielczością 10°, oraz obciążeń wynikających z maksymalnych przyspieszeń i opóźnień napędów manipulatora. W [7] wykonana jest optymalizacja topologiczna komponentów egzoszkieletu kończyny górnej przy użyciu dwóch metod. Autorzy wykonali optymali- zację dla pojedynczej konfiguracji, dla której naprężenia konstrukcji są największe.…”

Structural Optimization Design of a Six-Degrees-of-Freedom Serial Robot with Integrated Topology and Dimensional Parameters

“…Serial robots [ 5 , 6 , 7 ] are essential components of robots. The complex parameter coupling and multi-objective design of serial robots have attracted the attention and research of scholars [ 8 , 9 , 10 , 11 ]. To address the structural requirements for serial robots in different environments, researchers evaluate and improve the performance of robots through simulations, providing accurate design and optimization solutions [ 12 , 13 ].…”