Optimization Method of Location for Cooperative Lifting of Two Mobile Cranes

2012 ◽  
Author(s):  
Xin Wang ◽  
Yuanyuan Liu ◽  
Fang Liu
Keyword(s):  
Collision Detection ◽  
Optimization Method ◽  
Step Length ◽  
Optimal Location ◽  
Bisection Method ◽  
Important Work ◽  
Optimization Function ◽  
Search Field ◽  
Weighted Optimization ◽  
Work Envelope

Dual-crane lifting has been generally used with the need of erection and installation of large equipment. Choosing proper locations for two mobile cranes is an important work as well as a difficulty in design of heavy lifting plan. So, this paper proposes an optimization method of location for cooperative lifting of dual-crane. This approach starts with determining search field and maximum step length, and then finds out load’s possible initial locations by bisection method; secondly calculates work envelope of dual-crane which will be dispersed to find all dual-crane’s possible locations; after this, it puts cranes in their respective possible locations corresponding to each load’s location and simulates the whole lifting course while carries out collision detection to exclude crash happened locations; finally, creates weighted optimization function, uses enumeration method to traverse all collision-free locations, and gains optimal location of dual-crane and load. At last, this approach has been used in an actual engineering case and optimal location is got, from which we can see its feasibility and validity.

Simplified Modeling Research of Reinforced Concrete Based on the Dynamic Stiffness Equivalence

2012 ◽  
Vol 446-449 ◽  
pp. 458-462
Author(s):  
Jie Hu ◽  
Jia Quan Feng ◽  
Xi Nong Zhang
Keyword(s):  
Reinforced Concrete ◽  
Reference Model ◽  
Dynamic Stiffness ◽  
Optimization Method ◽  
Simplified Model ◽  
Response Analysis ◽  
Reinforced Concrete Structure ◽  
Optimization Function ◽  
Nature Frequency ◽  
Simplified Modeling

This paper proposed a simplified modeling method of reinforced concrete based on the equivalence of dynamic stiffness, the parameters of simplified model were modified to make the error of nature frequency between reference model and simplified model as small as possible, and an appropriate optimization function was designed. The essentiality of the proposed method is parameter optimization, with the advantages such as fewer elements and calculation assumption. The numerical simulation result indicated that this optimization method is suitable for the dynamic response analysis of complicated reinforced concrete structure.

scholarly journals Effects of upper body parameters on biped walking efficiency studied by dynamic optimization

2016 ◽  
Vol 14 (1) ◽  
pp. 172988141668270 ◽  
Author(s):  
Kang An ◽  
Chuanjiang Li ◽  
Zuhua Fang ◽  
Chengju Liu
Keyword(s):  
Body Length ◽  
Dynamic Optimization ◽  
Optimal Solution ◽  
Optimization Method ◽  
Step Length ◽  
Joint Torque ◽  
Upper Body ◽  
Walking Gait ◽  
Body Parameters ◽  
Walking Efficiency

Walking efficiency is one of the considerations for designing biped robots. This article uses the dynamic optimization method to study the effects of upper body parameters, including upper body length and mass, on walking efficiency. Two minimal actuations, hip joint torque and push-off impulse, are used in the walking model, and minimal constraints are set in a free search using the dynamic optimization. Results show that there is an optimal solution of upper body length for the efficient walking within a range of walking speed and step length. For short step length, walking with a lighter upper body mass is found to be more efficient and vice versa. It is also found that for higher speed locomotion, the increase of the upper body length and mass can make the walking gait optimal rather than other kind of gaits. In addition, the typical strategy of an optimal walking gait is that just actuating the swing leg at the beginning of the step.

scholarly journals The Method of MMC Redundancy Optimization Allocation Based on Multi-objective Optimization

2018 ◽  
Vol 173 ◽  
pp. 03075
Author(s):  
Enshu Jin ◽  
Yagu Zhang
Keyword(s):  
Optimization Method ◽  
Normal Operation ◽  
Multi Objective Optimization ◽  
Configuration Optimization ◽  
Multi Objective ◽  
Optimal Value ◽  
Optimization Function ◽  
Multi Level ◽  
Optimization Allocation ◽  
Level Converter

When the modular multi-level converter of the sub-module faults, which will cause the unbalanced system, affect the normal operation of the system, so to the MMC arm configuration redundant sub-module is necessary, if the sub-module faults, redundant sub-modules will replace the fault sub-module maintaining the normal operation of system. In this paper, we propose a reasonable and effective method for the configuration optimization of redundant sub-module based on the three indexes, namely, efficient utilization of redundant sub-module, the number of redundant sub-module and the reliability of the system MMC, considering the three factors, establishing a multi-objective optimization function of redundant configuration, By calculating the optimal value to accurately calculate the number of redundant sub-module of MMC, based on the proposed redundancy configuration optimization method, building a simulation model of MMC 5 level in PSCAD, the results verify the rationality and feasibility of the proposed optimization method.

Research on Machining Virtual Reality System

2013 ◽  
Vol 546 ◽  
pp. 70-75
Author(s):  
Q.N. Hu ◽  
D.J. Feng ◽  
H. Shu ◽  
H.Z. Dai ◽  
J.L. Wu
Keyword(s):  
Virtual Reality ◽  
Operating Procedure ◽  
Collision Detection ◽  
Optimization Method ◽  
Machining Process ◽  
Virtual Reality System ◽  
Virtual Machining ◽  
Modular Programming ◽  
Experimental Instruction ◽  
Virtual Worker

A machining virtual reality system is established by studying the operating procedure of machining. The modeling and optimization method of scene model is put forward. Two different roaming ways, that is the automatic roaming path and the free roaming path, are designed. The process of machine and the operation of virtual worker are simulated based on the technique of modular programming and collision detection in Virtools, enhancing the sense of immersion and reality of the virtual machining process. The system provides a new method for machining experimental instruction.

Research on Evolutionary Topology Optimization in ANSYS

2013 ◽  
Vol 572 ◽  
pp. 547-550 ◽  
Author(s):  
Dong Yan Shi ◽  
Jia Shan Han ◽  
Ling Cheng Kong ◽  
Lin Lin
Keyword(s):  
Topology Optimization ◽  
Optimization Method ◽  
Secondary Development ◽  
Filter Method ◽  
Ansys Software ◽  
Evolutionary Structural Optimization ◽  
Elemental Sensitivity ◽  
Beso Method ◽  
Optimization Function ◽  
2D And 3D

Topology optimization function in ANSYS software is inefficient with the limitation of element types. By using the secondary developing language APDL and UIDL, the secondary development of bi-directional evolutionary structural optimization (BESO) method with volume constraint and stiffness maximization is completed in ANSYS. To suppress the checkerboard patterns, the elemental sensitivity numbers are recalculated by a filter method. To ensure the convergence of the optimization method in ANSYS, the elemental sensitivity numbers are updated by adding in their historical information. Two classic numerical examples are calculated to obtain the best topology structure. The numerical results indicate that the secondary method can solve the 2D and 3D problems effectively, which makes up for the deficiency of topology optimization part in ANSYS and broadens the application scope of the evolutionary optimization method.

scholarly journals Segmentation of Meristem Cells by an Automated Optimization Algorithm

2020 ◽  
Vol 10 (23) ◽  
pp. 8523
Author(s):  
Oswaldo Rojas ◽  
Manuel G. Forero ◽  
José M. Menéndez ◽  
Angharad Jones ◽  
Walter Dewitte ◽  
...  
Keyword(s):  
Level Set ◽  
Automatic Segmentation ◽  
Optimization Method ◽  
Intensity Level ◽  
Low Contrast ◽  
Segmentation Methods ◽  
Segmented Images ◽  
Optimization Function ◽  
Confocal Images ◽  
Automated Optimization

Meristem cells are irregularly shaped and appear in confocal images as dark areas surrounded by bright ones. Images are characterized by regions of very low contrast and absolute loss of edges deeper into the meristem. Edges are blurred, discontinuous, sometimes indistinguishable, and the intensity level inside the cells is similar to the background of the image. Recently, a technique called Parametric Segmentation Tuning was introduced for the optimization of segmentation parameters in diatom images. This paper presents a PST-tuned automatic segmentation method of meristem cells in microscopy images based on mathematical morphology. The optimal parameters of the algorithm are found by means of an iterative process that compares the segmented images obtained by successive variations of the parameters. Then, an optimization function is used to determine which pair of successive images allows for the best segmentation. The technique was validated by comparing its results with those obtained by a level set algorithm and a balloon segmentation technique. The outcomes show that our methodology offers better results than two free available state-of-the-art alternatives, being superior in all cases studied, losing 9.09% of the cells in the worst situation, against 75.81 and 25.45 obtained in the level set and the balloon segmentation techniques, respectively. The optimization method can be employed to tune the parameters of other meristem segmentation methods.

An Optimization Method Selecting the Location Points for Drilling and Riveting of Aircraft’s Wing Panel

2011 ◽  
Vol 80-81 ◽  
pp. 1103-1108
Author(s):  
Kai Fu Zhang ◽  
Feng Gang Liu ◽  
Zhen Xing Liu ◽  
Yuan Li
Keyword(s):  
Search Algorithm ◽  
Scatter Search ◽  
Optimization Method ◽  
Optimal Location ◽  
Linear Programming Method ◽  
Matching Method ◽  
Riveting Process ◽  
Minimal Deviation ◽  
Scatter Search Algorithm ◽  
Wing Panel

In order to select the optimal location points for automated drilling and riveting process, an optimization method selecting the location points of Aircraft’s Wing Panel in Automatic Drilling and Riveting System is presented. This method includes three steps: 1) building the matching model based on the multiplicity; 2) presenting the matching method based on scatter search algorithm; 3) selecting the optimal location points according to the minimal deviation based on linear programming method. This method was applied in a panel to match the mathematical surface and the fitting one of this panel perfectly and select the optimal location points. The efficacy and quality during the process of drilling and riveting of this panel was improved greatly.

scholarly journals Updated Bayes identification of displacement constants of curve indeterminate box girder with variable scale theory

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881763
Author(s):  
Cheng Xi ◽  
Zhang Jian ◽  
Jia Chao ◽  
Tian Jiawei
Keyword(s):  
Objective Function ◽  
Optimization Theory ◽  
Optimization Method ◽  
Step Length ◽  
Mechanical Analysis ◽  
Box Girder ◽  
Scale Theory ◽  
Automatic Search ◽  
Scale Optimization ◽  
Identification Model

For curve indeterminate box girder, updated Bayes identification model of displacement constants was derived and studied with the variable-scale optimization theory. First, the updated Bayes objective function of displacement constants of the structure was founded. The gradient matrix of the objective function to displacement constants and the calculative covariance matrix were both deduced. Then, with finite curve strip element method, mechanical analysis of curve indeterminate box girder was completed. With automatic search scheme of quadratic parabola interpolation for optimal step length, the variable scale theory was utilized to optimize the updated Bayes objective function. Then, the identification steps were expounded, and the identification procedure was developed. Through typical examples, it is achieved that the updated Bayes identification model of displacement constants has numerical stability and perfect convergence. The stochastic performances of systematic parameters and systematic responses are simultaneously deliberated in updated Bayes objective function, which can synchronously take the actual measured information at different times into account. The variable-scale optimization method continually changes the spatial matrix scale to generate renewed search directions during the iterations, which certainly accelerates the identification of the displacement constants.

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