Multiobjective Optimization of 6‐DOF Parallel Manipulator for Desired Total Orientation Workspace

Abstract

A desired total orientation workspace for a parallel manipulator is usually an essential requirement in a practical application. At present, for the multiobjective optimization method of 6-DOF parallel manipulator for desired total orientation workspace, it is needed to predefine maximal and minimal lengths of the legs to serve as the constraint, and then the numerical method is used to solve the length of the legs and judge whether the solved maximal and minimal leg lengths meet the constraint. Predefining maximal and minimal length of the legs limits of the optimal range, the numerical method has heavy calculation burden and low calculating accuracy. In this paper, a hybrid method for solving the maximal and minimal lengths of the legs of 6-DOF parallel manipulator with desired total orientation workspace is proposed, and the actuator stroke length is calculated according to the maximal and minimal leg lengths. By judging whether the actuator stroke length can be solved to serve as the constraint, without the predefined maximal and minimal leg lengths to serve as the constraint, the optimal range is enlarged. Aiming at the physical size of the parallel manipulator and the proposed desired workspace condition index (DWCI), the optimization of the geometric parameters of the parallel manipulator is conducted based on the multiobjective optimization algorithm (NSGA-II), which is subject to the actuator stroke length. Stewart platform is set as the example; the geometric parameters of the platform whose workspace contains the desired total orientation workspace are optimized and the hybrid method is proved to be more accurate and efficient compared to the traditional numerical method. This method provides the optimization guidance for engineering designers to design the parallel manipulator for desired total orientation workspace.

Optimal design of tricept parallel manipulator with particle swarm optimization using performance parameters

“…Industrial Advances in Machining Parameters particle swarm Optimization for materials were done using Response Surface Methodology (Lmalghan et al, 2018). Further, multiobjective optimization is used for 6-DOF Parallel Manipulator for setting total Workspace (Qiang et al, 2019). Recently, parametric performances of parallel structures with 3 or higher degrees of freedom are being controlled to get maximum dexterity (Xie et al, 2019).…”

Two Design Proposals and Working Space Comparison for 3-CCC Type Robot with 6 Degrees of Freedom

“…Kim ve arkadaşları 6 serbestlik derecesine sahip mekanizmada herhangi bir dönme ekseninde, sınırsız 360 derece sürekli dönüş ve sonlu X, Y ve Z ekseni öteleme hareketini sağlama üzerinde çalışma yapmışlardır [5]. Qiang ve arkadaşları toplam oryantasyon çalışma alanı için 6-SD paralel manipülatörün çok amaçlı optimizasyonunu gerçekleştirmişlerdir [6]. İnner ve Küçük, genel stewart platform mekanizmalarının tasarım, analiz ve benzetiminin yapılabileceği STEWSIM isimli simülasyon aracını geliştirmişlerdir [7].…”

Multi-objective Optimization of Compliant Parallel Platform for Desired Stiffness and Workspace

“…In [12,13], typical non-dimensional performance indices were used to optimize the geometric parameters of a 3-DOF parallel kinematic structure. Considering the performance criteria of the 6-DOF parallel manipulators, a multi-objective optimization is formulated in [7,14,15].…”

“…Stiffness, precision, and workspace [6,7] are typical performance indexes of a mechanism. Though many studies have shown that the precision of CPP is able to meet the needs, in most application scenarios, the limited stiffness and workspace of CPPs still confine the scope of their application.…”