scholarly journals A Globally Optimal Robust Design Method for Complex Systems

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-25
Author(s):  
Yue Chen ◽  
Jian Shi ◽  
Xiao-jian Yi
Keyword(s):  
Complex Systems ◽  
Design Parameter ◽  
Design Method ◽  
Solution Space ◽  
Maximum Size ◽  
Design Criterion ◽  
Design Parameters ◽  
Engineering System ◽  
Output Performance ◽  
Maximum Solution

The uncertainty of the engineering system increases with the growing complexity of the engineering system; therefore, the tolerance to the uncertainty is essential. In the design phase, the output performance should reach the design criterion, even under large variations of design parameters. The tolerance to design parameter variations may be measured by the size of a solution space in which the output performance is guaranteed to deliver the required performance. In order to decouple dimensions, a maximum solution hyperbox, expressed by intervals with respect to each design parameter, is sought. The proposed approach combines the metaheuristic algorithm with the DIRECT algorithm where the former is used to seek the maximum size of hyperbox, and the latter is used as a checking technique that guarantees the obtained hyperbox is indeed a solution hyperbox. There are three advantages of the proposed approach. First, it is a global search and has a considerable high possibility to produce the globally maximum solution hyperbox. Second, it can be used for both analytically known and black-box performance functions. Third, it guarantees that any point selected within the obtained hyperbox satisfies the performance criterion as long as the performance function is continuous. Furthermore, the proposed approach is illustrated by numerical examples and real examples of complex systems. Results show that the proposed approach outperforms the GHZ and CES-IA methods in the literature.

scholarly journals Design Improvement for Complex Systems with Uncertainty

Mathematics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1173
Author(s):  
Yue Chen ◽  
Jian Shi ◽  
Xiao-Jian Yi
Keyword(s):  
Complex Systems ◽  
System Performance ◽  
Black Box ◽  
Design Parameters ◽  
Engineering System ◽  
Engineering Knowledge ◽  
Design Improvement ◽  
Design Goal ◽  
Maximum Solution ◽  
High Possibility

The uncertainty of the engineering system increases with its complexity, therefore, the tolerance to the uncertainty becomes important. Even under large variations of design parameters, the system performance should achieve the design goal in the design phase. Therefore, engineers are interested in how to turn a bad design into a good one with the least effort in the presence of uncertainty. To improve a bad design, we classify design parameters into key parameters and non-key parameters based on engineering knowledge, and then seek the maximum solution hyper-box which already includes non-key parameters of this bad design. The solution hyper-box on which all design points are good, that is, they achieve the design goal, provides target intervals for each parameter. The bad design can be turned into a good one by only moving its key parameters into their target intervals. In this paper, the PSO-Divide-Best method is proposed to seek the maximum solution hyper-box which is in compliance with the constraints. This proposed approach has a considerably high possibility to find the globally maximum solution hyper-box that satisfies the constraints and can be used in complex systems with black-box performance functions. Finally, case studies show that the proposed approach outperforms the EPCP and IA-CES methods in the literature.

Identifying Key Parameters for Design Improvement in High-Dimensional Systems With Uncertainty

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Johannes Fender ◽  
L. Graff ◽  
H. Harbrecht ◽  
Markus Zimmermann
Keyword(s):  
Numerical Optimization ◽  
Solution Space ◽  
Design Criterion ◽  
Design Parameters ◽  
High Dimensional ◽  
Design Work ◽  
Good Design ◽  
Design Improvement ◽  
Front Structure ◽  
Key Parameter

Key parameters may be used to turn a bad design into a good design with comparatively little effort. The proposed method identifies key parameters in high-dimensional nonlinear systems that are subject to uncertainty. A numerical optimization algorithm seeks a solution space on which all designs are good, that is, they satisfy a specified design criterion. The solution space is box-shaped and provides target intervals for each parameter. A bad design may be turned into a good design by moving its key parameters into their target intervals. The solution space is computed so as to minimize the effort for design work: its shape is controlled by particular constraints such that it can be reached by changing only a small number of key parameters. Wide target intervals provide tolerance against uncertainty, which is naturally present in a design process, when design parameters are unknown or cannot be controlled exactly. In a simple two-dimensional example problem, the accuracy of the algorithm is demonstrated. In a high-dimensional vehicle crash design problem, an underperforming vehicle front structure is improved by identifying and appropriately changing a relevant key parameter.

A New Structure Design Method for Improve Modular Joint Output Performance in Modular Robot

2014 ◽  
Vol 635-637 ◽  
pp. 1299-1302 ◽  
Author(s):  
Xiao Li ◽  
Han Xu Sun ◽  
Ying Wen Tang ◽  
Jing Zhou Song
Keyword(s):  
Design Method ◽  
Structure Design ◽  
Design Parameters ◽  
Modular Robot ◽  
Positioning Accuracy ◽  
Brushless Dc ◽  
Output Performance ◽  
Output Torque ◽  
Novel Structure ◽  
Dc Servomotor

A novel structure design method to improve the output performance in course of modular robot is presented in this paper. The new design parameter of modular joint is defined based on analysis of existing joint. Output torque and Max speed is increased by means of different Brushless DC-Servomotor and harmonic reducer in limited interspace. The repeated positioning accuracy is not reduced when output torque and Max speed are increased. And parts of the process parameters is improved. The new design parameters show that the design method is feasible.

scholarly journals A modular design method based on TRIZ and AD and its application to cutter changing robot

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110343
Author(s):  
Mei Yang ◽  
Yimin Xia ◽  
Lianhui Jia ◽  
Dujuan Wang ◽  
Zhiyong Ji
Keyword(s):  
Modular Design ◽  
Design Method ◽  
Idea Generation ◽  
Design Parameters ◽  
Problem Analysis ◽  
Concept Design ◽  
Functional Requirements ◽  
Shield Tunneling ◽  
Structural Hierarchy ◽  
And Performance

Modular design, Axiomatic design (AD) and Theory of inventive problem solving (TRIZ) have been increasingly popularized in concept design of modern mechanical product. Each method has their own advantages and drawbacks. The benefit of modular design is reducing the product design period, and AD has the capability of problem analysis, while TRIZ’s expertise is innovative idea generation. According to the complementarity of these three approaches, an innovative and systematic methodology is proposed to design big complex mechanical system. Firstly, the module partition is executed based on scenario decomposition. Then, the behavior attributes of modules are listed to find the design contradiction, including motion form, spatial constraints, and performance requirements. TRIZ tools are employed to deal with the contradictions between behavior attributes. The decomposition and mapping of functional requirements and design parameters are carried out to construct the structural hierarchy of each module. Then, modules are integrated considering the connections between each other. Finally, the operation steps in application scenario are designed in temporal and spatial dimensions. Design of cutter changing robot for shield tunneling machine is taken as an example to validate the feasibility and effectiveness of the proposed method.

scholarly journals A Two-Round Optimization Design Method for Aerostatic Spindles Considering the Fluid–Structure Interaction Effect

2021 ◽  
Vol 11 (7) ◽  
pp. 3017
Author(s):  
Qiang Gao ◽  
Siyu Gao ◽  
Lihua Lu ◽  
Min Zhu ◽  
Feihu Zhang
Keyword(s):  
Optimal Design ◽  
Optimization Design ◽  
Design Method ◽  
Fluid Structure Interaction ◽  
Design Procedure ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Aerostatic Spindle

The fluid–structure interaction (FSI) effect has a significant impact on the static and dynamic performance of aerostatic spindles, which should be fully considered when developing a new product. To enhance the overall performance of aerostatic spindles, a two-round optimization design method for aerostatic spindles considering the FSI effect is proposed in this article. An aerostatic spindle is optimized to elaborate the design procedure of the proposed method. In the first-round design, the geometrical parameters of the aerostatic bearing were optimized to improve its stiffness. Then, the key structural dimension of the aerostatic spindle is optimized in the second-round design to improve the natural frequency of the spindle. Finally, optimal design parameters are acquired and experimentally verified. This research guides the optimal design of aerostatic spindles considering the FSI effect.

Research on the Optimal Design Method of the Main Components for the Wheelchair Pickup

2013 ◽  
Vol 791-793 ◽  
pp. 799-802
Author(s):  
Ya Ping Wang ◽  
H.R. Shi ◽  
L. Gao ◽  
Z. Wang ◽  
X.Y. Jia ◽  
...  
Keyword(s):  
Parametric Design ◽  
Design Method ◽  
Basic Function ◽  
Design Parameters ◽  
Algorithm Optimization ◽  
Optimization Analysis ◽  
Research Designs ◽  
Optimal Design Method ◽  
Main Components

With the increasing of the aging of population all over the world, and With the inconvenience coming from diseases and damage, there will be more and more people using the wheelchair as a tool for transport. When it cant be short of the wheelchair in the daily life, the addition of the function will bring the elevation of the quality of life for the unfortunate. Staring with this purpose, the research designs a pickup with planetary bevel gear for the wheelchair. After determining the basic function of the wheelchair aids, the study determines the design parameters by using the knowledge of parametric design and completes the model for the system with Pro/E, on the other hand, it completes key components optimization analysis which is based on genetic algorithm optimization.

Development of High-Speed Response Electromagnetic Linear Actuator Using for Pneumatic Control Valve

2014 ◽  
Vol 532 ◽  
pp. 41-45 ◽  
Author(s):  
Myung Jin Chung
Keyword(s):  
Optimal Design ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Design Method ◽  
Control Valve ◽  
Design Parameters ◽  
Linear Actuator ◽  
Analytic Model ◽  
Electromagnetic Linear Actuator ◽  
Quadratic Programming Method

Analytic model of electromagnetic linear actuator in the function of electric and geometric parameters is proposed and the effects of the design parameters on the dynamic characteristics are analyzed. To improve the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design method aims to minimize the response time and maximize force efficiency. By this procedure, electromagnetic linear actuator having high-speed characteristics is developed.

The Biomimetic Shark Skin Optimization Design Method for Improving Lubrication Effect of Engineering Surface

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Yan Lu ◽  
Meng Hua ◽  
Zuomin Liu
Keyword(s):  
Coefficient Of Friction ◽  
Optimization Design ◽  
Design Method ◽  
Theory Model ◽  
Tribological Performance ◽  
Design Parameters ◽  
Width Ratio ◽  
Textured Surface ◽  
Shark Skin ◽  
Biomimetic Surface

Nature has long been an important source of inspiration for mankind to develop artificial ways to mimic the remarkable properties of biological systems. In this work, a new method was explored to fabricate a biomimetic engineering surface comprising both the shark-skin, the shark body denticle, and rib morphology. It can help reduce water resistance and the friction contact area as well as accommodate lubricant. The lubrication theory model was established to predict the effect of geometric parameters of a biomimetic surface on tribological performance. The model has been proved to be feasible to predict tribological performance by the experimental results. The model was then used to investigate the effect of the grid textured surface on frictional performance of different geometries. The investigation was aimed at providing a rule for deriving the design parameters of a biomimetic surface with good lubrication characteristics. Results suggest that: (i) the increase in depression width ratio Λ decreases its corresponding coefficient of friction, and (ii) the small coefficient of friction is achievable when Λ is beyond 0.45. Superposition of depth ratio Γ and angle's couple under the condition of Λ < 0.45 affects the value of friction coefficient. It shows the decrease in angle decreases with the increase in dimension depth Γ.

Buckling Design of Axially Compressed Cylindrical Shells Based on Energy Barrier Approach

2021 ◽  
pp. 2150165
Author(s):  
Haigui Fan ◽  
Wenguang Gu ◽  
Longhua Li ◽  
Peiqi Liu ◽  
Dapeng Hu
Keyword(s):  
Experimental Data ◽  
Energy Barrier ◽  
Thin Shell ◽  
Design Method ◽  
Lightweight Design ◽  
Cylindrical Shells ◽  
Design Criterion ◽  
The Other ◽  
Shell Structures ◽  
Buckling Loads

Buckling design of axially compressed cylindrical shells is still a challenging subject considering the high imperfection-sensitive characteristic in this kind of structure. With the development of various design methods, the energy barrier concept dealing with buckling of imperfection-sensitive cylindrical shells exhibits a promising prospect in recent years. In this study, buckling design of imperfection-sensitive cylindrical shells under axial compression based on the energy barrier approach is systematically investigated. The methodology about buckling design based on the energy barrier approach is described in detail first taking advantage of the cylindrical shells whose buckling loads have been extensively tested. Then, validation and discussion about this buckling design method have been carried out by the numerical and experimental analyses on the cylindrical shells with different geometrical and boundary imperfections. Results in this study together with the available experimental data have verified the reliability and advantage of the buckling design method based on energy barrier approach. A design criterion based on the energy barrier approach is therefore established and compared with the other criteria. Results indicate that buckling design based on energy barrier approach can be used as an efficient way in the lightweight design of thin-shell structures.

Nonrelative sliding of spiral bevel gear mechanism based on active design of meshing line

2018 ◽  
Vol 233 (3) ◽  
pp. 1055-1067 ◽  
Author(s):  
Zhen Chen ◽  
Ming Zeng
Keyword(s):  
Design Method ◽  
Bevel Gear ◽  
Transmission Mechanism ◽  
Tooth Surface ◽  
Design Parameters ◽  
Spiral Bevel Gear ◽  
Bevel Gears ◽  
Gear Mechanism ◽  
Active Design ◽  
Spiral Bevel

In this paper, an active design method of meshing line for a spiral bevel gear mechanism with nonrelative sliding is presented. First, the general meshing line equations for a nonrelative sliding transmission mechanism between two orthogonal axes are proposed based on the active design parameters. Then, parametric equations for contact curves on the drive and driven spiral bevel gears are deduced by coordinate transformation of the meshing line equations. Further to this, parametric equations for the tooth surface of each bevel gear are derived according to the conical spiral motion of a generatrix circle along the calculated contact curves. Finally, a set of numerical examples is presented based on two types of motion equation of the meshing points. Material prototypes are fabricated and experimentally tested to validate the kinematic performance of the functionally designed spiral bevel gear set.

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