Multi-objective optimization design of a compliant microgripper based on hybrid teaching learning-based optimization algorithm

Measurement and Control

et al. 2019

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The surface quality and accuracy of the geometry of the cylindrical rollers are important factors for bearing life. This paper presents effects of machining parameters on the surface roughness, topography and roundness of cylindrical rollers through the lapping and polishing experiments. And then the surface roughness of the cylindrical rollers is optimized. The results found that the surface roughness of rollers is significantly changed in lapping process with different abrasive particle sizes, while the surface roughness has slightly reduced in polishing process. It also indicated that the smoother surfaces with better roughness can be obtained after lapping and polishing process. In addition, the surface roughness of cylindrical rollers is rapidly reduced from Ra of 0.5 µm to Ra of 0.063 µm after the 3-h lapping process and Ra of 0.013 µm after the 1-h polishing process. The surface topography of rollers can be achieved by the smoother surface when loads are from 25 to 35 N in lapping process, and the loads are from 35 to 40 N in polishing process. Finally, the Taguchi method is applied to optimize the surface roughness in polishing process. The result found that the optimal surface roughness achieves 0.015 µm with respect to the time of 35 min and type of 4000# Al2O3.

Section: Optimization For Surface Roughness In Polishing Processmentioning

confidence: 99%

Experimental study on polishing process of cylindrical roller bearings

Nguyen

Measurement and Control

et al. 2019

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“…Unlike previous studies, the present study is based on the sensitivity of responses, an effect of design variables on the responses, and statisticalbased equation sets were established to produce weighting formulas. This study follows a statistical method based on signal-to-noise (S/N) ratio [42]. One of the most important tasks is that each objective function should be normalized in the range [0, 1].…”

Section: Proposed Hybrid Methodologymentioning

confidence: 99%

“…To optimize the multiple responses, most previous studies assigned the weight factor (WF) for each objective function according to the expert's experience or customer's requirements but a wrong experience may result in an unprecise optimal solution. Therefore, we follow a calculation of WF in [42].…”

Section: Introductionmentioning

confidence: 99%

Efficient Hybrid Method of FEA-Based RSM and PSO Algorithm for Multi-Objective Optimization Design for a Compliant Rotary Joint for Upper Limb Assistive Device

Mathematical Problems in Engineering

et al. 2019

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This paper proposes an efficient hybrid methodology for multi-objective optimization design of a compliant rotary joint (CRJ). A combination of the Taguchi method (TM), finite element analysis (FEA), the response surface method (RSM), and particle swarm optimization (PSO) algorithm is developed to solving the optimization problem. Firstly, the TM is applied to determine the number of numerical experiments. And then, 3D models of the CRJ is built for FEA simulation, and mathematical models are formed using the RSM. Subsequently, the suitability of the regression equation is assessed. At the same time, the calculation of weight factors is identified based on the series of statistical equations. Based on the well-established equations, a minimum mass and a maximum rotational angle are simultaneously optimized through the PSO algorithm. Analysis of variance is used to analyze the contribution of design variables. The behavior of the proposed method is compared to the adaptive elitist differential evolution and cuckoo search algorithm through the Wilcoxon signed rank test and Friedman test. The results determined the weight factors of the mass and rotational angle are about 0.4983 and 0.5017, respectively. The results found that the optimum the mass and rotational angle are 0.0368 grams and 59.1928 degrees, respectively. It revealed that the maximum stress of 335 MPa can guarantee a long working time. The results showed that the proposed hybrid method outperforms compared to other evolutionary algorithms. The predicted results are close to the validation results. The proposed method is useful for related engineering fields.

“…Laminar emergent mechanism (LEM) is a subbranch of compliant mechanisms (CMs). LEM's functions are similar those of CMs which transfer force, motion, and energy [1][2][3][4][5][6]. CMs can be manufactured by the 3D printing technique, wire discharged machining process, or CNC machine from a solid [7,8].…”

Section: Introductionmentioning

confidence: 99%

Design and Performance Analysis of a TLET-Type Flexure Hinge

Tran

Advances in Materials Science and Engineering

2020

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In order to permit a large deflection, three lamina emergent torsional flexure hinges are reconfigured to create a new triple LET-type flexure hinge (TLET) in this paper. The TLET consists of flexure hinges in a series coupled with others in parallel configuration. This arrangement is aimed to enhance the displacement of the joint. The proposed joint is capable of generating a large displacement and a large capacity of load within safety working conditions. The closed-form models are derived to calculate the equivalent spring constant, rotation angle, and displacement of the proposed joint. Failure analysis of the TLET joint with different materials is conducted by finite element analysis. The closed-form models are validated by simulations and experimentations. The validated results are well coincided each other. The result found that the joint achieves a maximum large displacement of 16.97 mm in the x-axis with respect to a maximum load of 20 N. When the joint slides a maximum displacement of 16.97 mm along the x-axis, the output displacement emerges out the z-axis up to 23.12 mm, respectively. The joint can achieve an angle displacement of 38.92°. The displacement of the TLET joint is 2.4 times greater than that of the traditional LET joint. The proposed joint is considered for engineering applications where a large working stroke and a large capacity of load are expected.