Kinematic Analysis and Optimal Design of a Novel Schönflies-Motion Parallel Manipulator with Rotational Pitch Motion for Assembly Operations

2021 ◽  
pp. 1-17
Author(s):  
Xiansheng Yang ◽  
Zhilong Zhao ◽  
Hao Xiong ◽  
Qinchuan Li ◽  
Yunjiang Lou
Keyword(s):  
Optimal Design ◽  
Design Optimization ◽  
Cross Sections ◽  
Parallel Manipulator ◽  
Pitch Motion ◽  
Optimization Formulation ◽  
Kinematic Performance ◽  
Schönflies Motion ◽  
Assembly Operations ◽  
Orientation Workspace

Abstract This paper presents a novel Schönflies-motion Parallel Manipulator with Rotational Pitch motion (SPM-RP) based on a single-platform fully-parallel mechanism. The analysis of position, workspace, velocity, and singularity of the SPM-RP is carried out in detail, and a dimensionless Jacobian is proposed to evaluate the manipulability of the SPM-RP. It is shown that the SPM-RP is kinematically position-decoupled, which possesses a large singularity-free workspace and excellent manipulability. The SPM-RP is actuated by four parallel prismatic actuators, enabling the manipulator to provide identical kinematic performance at all generic cross-sections perpendicular to the prismatic joint axes within its workspace. This paper thus proposes a reduced design optimization formulation, where the traditional optimization over the entire workspace is reduced to one on a representative workspace cross-section of the SPM-RP. The design optimization of the SPM-RP has been carried out by maximizing its manipulability over the total orientation workspace, which is crucial for precision assembly. A SPM-RP prototype has been developed based on the achieved optimal design. The mobility, orientation capability, total orientation workspace, and repeatability are tested and verified for the developed SPM-RP prototype. Experiments show that the SPM-RP achieves a large total orientation workspace with excellent precision performance.

Optimal design of steel pipe rack structures using PSO, GWO, and IGWO algorithms

2021 ◽  
pp. 136943322110041
Author(s):  
Pooya Zakian ◽  
Behnam Ordoubadi ◽  
Erfan Alavi
Keyword(s):  
Optimal Design ◽  
Design Optimization ◽  
Cross Sections ◽  
Optimization Problem ◽  
Heuristic Algorithms ◽  
Cost Effective ◽  
Steel Pipe ◽  
Grey Wolf Optimizer ◽  
Grey Wolf ◽  
Industrial Structures

Design optimization of industrial structures is of great importance for engineers in order to provide a cost-effective structural design. Meanwhile, pipe rack is a skeletal industrial structure subjected to various types of loading such as gravity, seismic, piping, and thermal forces. While there are many studies on design optimization of the most common structures, only a limited number of studies exist on optimal design of industrial structures. In this article, a design optimization problem is proposed for weight minimization of steel pipe rack structures, and then the problem is solved through three meta-heuristic algorithms consisting of a modified particle swarm optimization (PSO), grey wolf optimizer (GWO), and the recently developed improved grey wolf optimizer (IGWO). The optimization problem is in discrete form in order to consider practically available cross-sections for the structural members. Stress ratio, drift, and dimensional constraints are imposed during the optimization. In order to demonstrate the capability and effectiveness of the present design optimization problem, a pipe rack structure is optimized by the proposed algorithms, and the optimized designs are compared to an ordinary design in terms of the structural weight and the status of constraints.

Optimal design of CaPaMan (Cassino Parallel Manipulator) with a specified orientation workspace

Robotica ◽  
2002 ◽  
Vol 20 (2) ◽  
pp. 159-166 ◽  
Author(s):  
Erika Ottaviano ◽  
Marco Ceccarelli
Keyword(s):  
Optimal Design ◽  
Optimum Design ◽  
Parallel Manipulator ◽  
Degree Of Freedom ◽  
Orientation Workspace

CaPaMan (Cassino Parallel Manipulator) is a 3-Degree Of Freedom spatial parallel manipulator that has been designed at the Laboratory of Robotics and Mechatronics, in Cassino. In this paper we present a formulation for an optimum design for CaPaMan architecture when the orientation workspace is suitably specified.

Optimal design of a redundant spherical parallel manipulator

Robotica ◽  
1997 ◽  
Vol 15 (4) ◽  
pp. 399-405 ◽  
Author(s):  
Sylvie Leguay-Durand ◽  
Claude Reboulet
Keyword(s):  
Optimal Design ◽  
Kinematic Analysis ◽  
Parallel Manipulator ◽  
Structure Optimization ◽  
Kinematic Design ◽  
Spherical Wrist ◽  
Redundant Structure ◽  
Spherical Parallel Manipulator

A new kinematic design of a parallel spherical wrist with actuator redundancy is presented. A special feature of this parallel manipulator is the arrangement of co-axial actuators which allows unlimited rotation about any axis inside a cone-shaped workspace. A detailed kinematic analysis has shown that actuator redundancy not only removes singularities but also increases workspace while improving dexterity. The structure optimization has been performed with a global dexterity criterion. Using a conditioning measure, a comparison with a non-redundant structure of the same type was performed and shows that a significant improvement in dexterity has been obtained.

Shape-design optimization of hull structures considering thermal deformation

2013 ◽  
Vol 228 (13) ◽  
pp. 2266-2277
Author(s):  
Myung-Jin Choi ◽  
Min-Geun Kim ◽  
Seonho Cho
Keyword(s):  
Optimal Design ◽  
Design Optimization ◽  
Thermal Deformation ◽  
Parametric Design ◽  
Optimization Method ◽  
Optimization Process ◽  
Design Parameters ◽  
Shape Design ◽  
Shape Design Optimization ◽  
Modified Method

We developed a shape-design optimization method for the thermo-elastoplasticity problems that are applicable to the welding or thermal deformation of hull structures. The point is to determine the shape-design parameters such that the deformed shape after welding fits very well to a desired design. The geometric parameters of curved surfaces are selected as the design parameters. The shell finite elements, forward finite difference sensitivity, modified method of feasible direction algorithm and a programming language ANSYS Parametric Design Language in the established code ANSYS are employed in the shape optimization. The objective function is the weighted summation of differences between the deformed and the target geometries. The proposed method is effective even though new design variables are added to the design space during the optimization process since the multiple steps of design optimization are used during the whole optimization process. To obtain the better optimal design, the weights are determined for the next design optimization, based on the previous optimal results. Numerical examples demonstrate that the localized severe deviations from the target design are effectively prevented in the optimal design.

Integrated optimal design of a high-speed planar parallel manipulator

2018 ◽  
Vol 233 (9) ◽  
pp. 2976-2990 ◽  
Author(s):  
Zhengsheng Chen ◽  
Minxiu Kong
Keyword(s):  
Optimal Design ◽  
Parallel Manipulator ◽  
High Speed ◽  
Design Method ◽  
Tracking Error ◽  
Dimensional Synthesis ◽  
Tracking Accuracy ◽  
Nsga Ii ◽  
Parameters Tuning ◽  
Planar Parallel Manipulator

To obtain excellent comprehensive performances of the planar parallel manipulator for the high-speed application, an integrated optimal design method, which integrated dimensional synthesis, motors/reducers selection, and control parameters tuning, is proposed, and the 3RRR parallel manipulator was taken as the example. The kinematic and dynamic performances of condition number, velocity index, acceleration capability, and low-order frequency are taken into accounts for the dimensional synthesis. Then, to match motors/reducers parameters and keep an economical cost, the constraint equations and the parameters library are built, and the cost is chosen as one of the optimization objectives. Also, to get high tracking accuracy, the dynamic forward plus proportional–derivative control scheme is introduced, and the tracking error is chosen as one of the optimization objectives. Hence, the optimization model including dimensional synthesis, motors/reducers selection and controller parameters tuning is established, which is solved by the genetic algorithm II (NSGA-II). The result shows that comprehensive performances can be effectively promoted through the proposed integrated optimal design, and the prototype was constructed according to the Pareto-optimal front.

Optimal Design of a 2-UPR-RPU Parallel Manipulator

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Feibo Wang ◽  
Qiaohong Chen ◽  
Qinchuan Li
Keyword(s):  
Optimal Design ◽  
Parallel Manipulator ◽  
Design Space ◽  
Parameter Design ◽  
Optimal Parameters ◽  
Force Transmission ◽  
Universal Joint ◽  
Practical Applications ◽  
Optimum Region ◽  
Dimensional Optimization

This paper investigates dimensional optimization of a 2-UPR-RPU parallel manipulator (where U is a universal joint, P a prismatic pair, and R a revolute pair). First, the kinematics and screws of the mechanism are analyzed. Then, three indices developed from motion/force transmission are proposed to evaluate the performance of the 2-UPR-RPU parallel manipulator. Based on the performance atlases obtained, a set of optimal parameters are selected from the optimum region within the parameter design space. Finally, the optimized parameters are determined for practical applications.

Sign in / Sign up

Export Citation Format

Share Document