Optimum exact/approximate point synthesis of planar mechanisms

Diab, Nadim; Smaili, Ahmad

doi:10.1016/j.mechmachtheory.2007.12.006

Cited by 28 publications

(8 citation statements)

References 33 publications

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“…This algorithm allows AS to be applied to various optimization problems regardless whether a physical path exists or not and this main advantage rendered it feasible in rigid mechanisms design [14][15][16][17][18] where an extensive detailed review can be found.…”

Section: Ant Search Algorithmmentioning

confidence: 99%

“…The authors of this paper used Ant Search (AS) to optimize for planar rigid linkages with hybrid function, motion and path synthesis tasks [14], hybrid exact-approximate path synthesis [15],clearances and tolerances effects in four bars [16] and coupler curve shape optimization [17]. Lately, a Modified Ant Search [18] algorithm was proposed to improve the performance of the AS algorithm by using an Elitist ants approach with dynamic enter/exit strategies between the exploration and exploitation phases.…”

Section: Introductionmentioning

confidence: 99%

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An Ants-Search Based Method for Optimum Synthesis of Compliant Mechanisms

Diab

Smaili

2016

Volume 11: Systems, Design, and Complexity

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Compliant mechanisms are widely used in the industry and have gained more popularity in the past few decades with the advancements in smart materials and micro-electro mechanical systems (MEMS). Compliant mechanisms offer huge advantages over the classical rigid linkages due to their flexible behavior. Such flexible mechanisms reduce production time and cost especially that they eliminate the need of joints that can get pretty hectic especially at micro level manufacturing and assembly. By avoiding multi-joints in the design and their consequent clearances, a compliant mechanism can offer higher precision over its rigid counterpart. However, these advantages come with a price; compliant mechanisms are more challenging in terms of design and analysis. Many compliant mechanisms are designed to undergo relatively large deflections which in turn impose geometric nonlinearities. In the past, many compliant designs were based on intuition, experience, and trial and error. Later on, many theories developed to assist in designing and analyzing compliant mechanisms before proceeding with the manufacturing phase. This paper covers topology optimization of compliant structures using beam elements. The swarm intelligence technique known as Ant Search (AS) is used to find the optimum design that satisfies the required mechanism performance. A case study that involves the topology design of a miniature compliant displacement amplifier is presented and results are compared with the finite element solver ANSYS. The optimized topology mechanism produced a much larger amplification ratio as compared to that * Address all correspondence to this author presented in literature. Results produced show the high potential of swarm intelligence and AS in particular at solving multidisciplinary optimization problems that should not be limited to designs that involve physical paths. NOMENCLATUREAS Ant search PRBM Pseudo-rigid-body model SE Strain energy MSE Mutual strain energy l Beam element length b In-plane width t Out-of plane thickness A Beam element cross-sectional area ν Poisson ratio E Young's modulus δ out Output displacement

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Section: Ant Search Algorithmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

An Ants-Search Based Method for Optimum Synthesis of Compliant Mechanisms

Diab

Smaili

2016

Volume 11: Systems, Design, and Complexity

Self Cite

View full text Add to dashboard Cite

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“…An exact solution for this problem is not possible because of the limited number of dimensions available, but various techniques have been used for approximate solutions. The most common techniques used include conventional optimization methods (Tomas, 1968;Sancibrian et al, 2004;Diab and Smaili, 2008), using atlases of mechanisms (Zhang et al, 1984), simulated annealing (Ullah and Kota, 1996), and genetic algorithms or evolutionary algorithms (Cabrera et al, 2002;Laribi et al, 2004;Starosta, 2008;Lin, 2010).…”

Section: Introductionmentioning

confidence: 99%

Dimensional synthesis of mechanical linkages using artificial neural networks and Fourier descriptors

2015

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Abstract. Dimensional synthesis of mechanisms to trace given paths is an important problem with no exact solution. In this paper, the problem is divided into representation of curve shape and learning the relation between curve shape and mechanism dimensions. Curve shape is represented by Fourier descriptors of cumulative angular deviation of the curve, which do not depend on the position or scale of the curve. An artificial neural network (ANN) is trained to learn the (unknown) relation between the Fourier descriptors of a planar curve and the dimensions of the mechanism tracing that curve. Presented with any simple, closed, planar curve, the ANN suggests the dimensions of a four-bar whose coupler curve is similar in shape. A local optimization procedure further refines the results. Examples presented indicate the method is successful as long as the curve shape is such that the mechanism is able to trace it.

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“…Note that the two-phase synthesis method discussed in the literature cannot handle path synthesis problems with prescribed timing. Several optimization algorithms, including exact gradient [9], simulated annealing [13], genetic algorithm (GA) and modified GA [7,8,10,11,19,23,25], ant-gradient [6,17,26], genetic algorithmfuzzy logic [24], differential evolution (DE) and modified DE [14-16, 18, 19, 21, 22, 27], particle swarm optimization [19], GA-DE [20,28], and hybrid optimizer [29], are used to solve the optimization problems of path synthesis. In the one-phase synthesis method, the error function in [9][10][11][14][15][16][17][18][19][20][21][22] is based on the sum of the square of Euclidean distance error (termed the square deviation in this study) between the target points and the corresponding coupler points.…”

Section: Introductionmentioning

confidence: 99%

“…The error function in [23,24] is based on the orientation structural error of the fixed link. References [25,26] use other error functions as the objective function. Recently, Matekar and Gogate [27] proposed a modified distance error function for path synthesis problems with prescribed timing and obtained the lower transverse errors at the cost of the higher longitudinal errors because they thought the former is an indication of closeness between the generated and prescribed paths and the latter is an indication of the error in the timing.…”

Section: Introductionmentioning

confidence: 99%

Optimum Path Synthesis of a Geared Five-Bar Mechanism

Lin

2013

Advances in Mechanical Engineering

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Most studies on path synthesis problems are to trace simple or smooth trajectories. In this work, an optimum synthesis for several special trajectories generated by a geared five-bar mechanism is studied using the one-phase synthesis method. The synthesis problem for the special trajectories, which is originally studied using the two-phase synthesis method discussed in the literature, is a real challenge due to very few dimensionally proportioned mechanisms that can generate the special trajectories. The challenging special trajectories with up to 41 discrete points include a self-overlapping curve, nonsmooth curves with straight segments and vertices, and sophisticated shapes. The error function of the square deviation of positions is used as the objective function and the GA-DE evolutionary algorithm is used to solve the optimization problems. Findings show that the proposed method can obtain approximately matched trajectories at the cost of a tremendous number of evaluations of the objective function. Therefore, the challenging problems may serve as the benchmark problems to test the effectiveness and efficiency of synthesis methods and/or optimization algorithms. All the synthesized solutions have been validated using the animation of the SolidWorks assembly so that the obtained mechanisms are sound and usable.

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Optimum exact/approximate point synthesis of planar mechanisms

Cited by 28 publications

References 33 publications

An Ants-Search Based Method for Optimum Synthesis of Compliant Mechanisms

An Ants-Search Based Method for Optimum Synthesis of Compliant Mechanisms

Dimensional synthesis of mechanical linkages using artificial neural networks and Fourier descriptors

Optimum Path Synthesis of a Geared Five-Bar Mechanism

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