scholarly journals Fuzzy set based multi-objective optimization for eight-rod mechanism via sensitivity analysis

2017 ◽  
Vol 233 (2) ◽  
pp. 333-343 ◽  
Author(s):  
Yongjun Pan ◽  
Chao Zhang ◽  
Banghui Yin ◽  
Baohua Wang
Keyword(s):  
Sensitivity Analysis ◽  
Membership Function ◽  
Fuzzy Set ◽  
Optimization Problem ◽  
Optimization Procedure ◽  
Multi Objective Optimization ◽  
Wheel Loader ◽  
Multi Objective ◽  
Design Variables ◽  
Working Device

The wheel loader multi-rod mechanism working device, which can be considered as a rigid multibody system, is a crucial component for shoveling and loading material. The six-rod and eight-rod mechanisms are two popular working devices used in construction, mining and agriculture. However, the design of the eight-rod mechanism device has not received much more attention due to its emerging applications. In this paper, a fuzzy set based multi-objective optimization procedure for an eight-rod mechanism device is presented by taking advantage of design sensitivities. The sensitivity analysis is carried out to extract the several most relevant design variables so as to simplify the optimization problem. Furthermore, the fuzzy set theory is introduced to express each objective in terms of membership function, thus different objectives can be measured in the same dimension. As a result, the multi-objective optimization problem is converted into a single objective through the combined membership function. Finally, an eight-rod mechanism working device of a wheel loader is analyzed and optimized by using the proposed method. The results show that the optimal eight-rod mechanism can provide a better kinematic performance.

Multi-Objective Optimization of a Segmented Lunar Wheel Concept

2011 ◽  
Author(s):  
Michele Faragalli ◽  
Damiano Pasini ◽  
Peter Radzizsewski
Keyword(s):  
Optimization Problem ◽  
Element Model ◽  
Multi Objective Optimization ◽  
Stress Concentrations ◽  
Multi Objective ◽  
Optimization Framework ◽  
Multi Objective Genetic Algorithm ◽  
Design Variables ◽  
Rider Comfort ◽  
Original Concept

The goal of this work is to develop a systematic method for optimizing the structural design of a segmented wheel concept to improve its operating performance. In this study, a wheel concept is parameterized into a set of size and shape design variables, and a finite element model of the wheel component is created. A multi-objective optimization problem is formulated to optimize its directional compliance and reduce stress concentrations, which has a direct affect on the efficiency, traction, rider comfort, maneuverability, and reliability of the wheel. To solve the optimization problem, a Matlab-FE simulation loop is built and a multi-objective genetic algorithm is used to find the Pareto front of optimal solutions. A trade-off design is selected which demonstrates an improvement from the original concept. Finally, recommendations will be made to apply the structural optimization framework to alternative wheel conceptual designs.

Lifting and parallel lifting optimization by using sensitivity and fuzzy set for an earthmoving mechanism

2016 ◽  
Vol 231 (2) ◽  
pp. 192-203 ◽  
Author(s):  
Yongjun Pan ◽  
Liang Hou
Keyword(s):  
Sensitivity Analysis ◽  
Degrees Of Freedom ◽  
Mechanism Analysis ◽  
Multi Objective Optimization ◽  
Six Degrees Of Freedom ◽  
Multi Objective ◽  
Design Variables ◽  
Hybrid Mechanism ◽  
Analysis And Synthesis ◽  
Critical Components

Earthmoving equipment in motor graders, which can be considered to be complex multibody systems (MBSs), are critical components for earthwork, compaction and re-handling. They have not yet received much attention due to their unusual applications and complicated structures. In this paper, a comprehensive study of an earthmoving MBS, from the mechanism identification and sensitivity analysis to the multi-objective optimization, is presented. First, the earthmoving MBS is identified to be a six degrees-of-freedom spatial hybrid mechanism, where a three revolute-revolute-prismatic-spherical (RRPS) and one spherical subchain (so, RRPS-S) spatial parallel mechanism is the key subsystem, through the mechanism analysis and synthesis. An earthmoving virtual prototyping model is built according to the system topology and connectivity. The kinematic simulations are carried out by imposing corresponding driving functions. Afterwards, the sensitivity analysis is introduced to extract several most relevant design variables from the global ones. A multi-objective optimization process is carried out to improve working performance, where fuzzy sets are used to define different objectives. Results show that the optimal earthmoving mechanism provides better lifting and parallel lifting capabilities.

Comprehensive Optimum Design of Working Device of Loader Based on Sensitivity

2012 ◽  
Vol 490-495 ◽  
pp. 3027-3031
Author(s):  
Xiao Ming Wu ◽  
Gui Xiang Xiao ◽  
Rong Chen
Keyword(s):  
Sensitivity Analysis ◽  
Optimum Design ◽  
Design Process ◽  
Optimization Design ◽  
Virtual Prototype ◽  
Prototype Model ◽  
Wheel Loader ◽  
Iterative Optimization ◽  
Design Variables ◽  
Working Device

The optimization design process of working device of wheel loader is a multipurpose and multivariable. In this paper, the virtual prototype model of working device is established and detailed sensitivity analysis had taken for various purposes to the design variables. Then based on the sensitivity results, three schemes of design variables were presented and through iterative optimization with ADAMS, the lifting stability and other performances of wheel loader are improvement

scholarly journals Braille Block Detection via Multi-Objective Optimization from an Egocentric Viewpoint

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2775
Author(s):  
Tsubasa Takano ◽  
Takumi Nakane ◽  
Takuya Akashi ◽  
Chao Zhang
Keyword(s):  
Optimization Problem ◽  
Line Pair ◽  
Objective Functions ◽  
Multi Objective Optimization ◽  
Multi Objective ◽  
Optimization Framework ◽  
Visually Impaired People ◽  
Comprehensive Comparison ◽  
Basic Characteristics ◽  
Support Devices

In this paper, we propose a method to detect Braille blocks from an egocentric viewpoint, which is a key part of many walking support devices for visually impaired people. Our main contribution is to cast this task as a multi-objective optimization problem and exploits both the geometric and the appearance features for detection. Specifically, two objective functions were designed under an evolutionary optimization framework with a line pair modeled as an individual (i.e., solution). Both of the objectives follow the basic characteristics of the Braille blocks, which aim to clarify the boundaries and estimate the likelihood of the Braille block surface. Our proposed method was assessed by an originally collected and annotated dataset under real scenarios. Both quantitative and qualitative experimental results show that the proposed method can detect Braille blocks under various environments. We also provide a comprehensive comparison of the detection performance with respect to different multi-objective optimization algorithms.

Auto-sharing parameters for transfer learning based on multi-objective optimization

2021 ◽  
pp. 1-13
Author(s):  
Hailin Liu ◽  
Fangqing Gu ◽  
Zixian Lin
Keyword(s):  
Transfer Learning ◽  
Optimization Problem ◽  
Data Sets ◽  
Multi Objective Optimization ◽  
Particle Swarm Optimizer ◽  
Real World Data ◽  
Data Set ◽  
Target Task ◽  
Main Research ◽  
Multi Objective

Transfer learning methods exploit similarities between different datasets to improve the performance of the target task by transferring knowledge from source tasks to the target task. “What to transfer” is a main research issue in transfer learning. The existing transfer learning method generally needs to acquire the shared parameters by integrating human knowledge. However, in many real applications, an understanding of which parameters can be shared is unknown beforehand. Transfer learning model is essentially a special multi-objective optimization problem. Consequently, this paper proposes a novel auto-sharing parameter technique for transfer learning based on multi-objective optimization and solves the optimization problem by using a multi-swarm particle swarm optimizer. Each task objective is simultaneously optimized by a sub-swarm. The current best particle from the sub-swarm of the target task is used to guide the search of particles of the source tasks and vice versa. The target task and source task are jointly solved by sharing the information of the best particle, which works as an inductive bias. Experiments are carried out to evaluate the proposed algorithm on several synthetic data sets and two real-world data sets of a school data set and a landmine data set, which show that the proposed algorithm is effective.

A dynamic multi-objective optimization procedure for water cooling of a photovoltaic module

2021 ◽  
Vol 45 ◽  
pp. 101111
Author(s):  
Mohammad Hassan Shahverdian ◽  
Ali Sohani ◽  
Hoseyn Sayyaadi ◽  
Saman Samiezadeh ◽  
Mohammad Hossein Doranehgard ◽  
...  
Keyword(s):  
Optimization Procedure ◽  
Photovoltaic Module ◽  
Water Cooling ◽  
Multi Objective Optimization ◽  
Multi Objective

The Finite Element Analysis and the Multi-Objective Optimization Design of Spindle Systems of CNC Gantry Machine Tools

2016 ◽  
Vol 693 ◽  
pp. 243-250
Author(s):  
Zhi Zhong Guo ◽  
Yun Shun Zhang ◽  
Shi Hao Liu
Keyword(s):  
Machine Tools ◽  
Optimization Design ◽  
Multi Objective Optimization ◽  
Element Analysis ◽  
Multi Objective ◽  
Vibration Resistance ◽  
Design Variables ◽  
Force Coupling ◽  
The Finite Element Analysis ◽  
Spindle Structure

It is discovered that the vibration resistance of spindle systems needs to be improved based on the statics analysis, modal analysis and heating-force coupling analysis of spindle systems of CNC gantry machine tools. The design variables of optimization are set according to sensitivity analysis, multi-objective and dynamic optimization design is realized and its designing scheme is gained for spindle structure. The research results show that vibration resistance can be improved without change of the quality and static property of spindle systems of CNC gantry machine tools.

Sign in / Sign up

Export Citation Format

Share Document