Multi-objective optimal design of flexible-joint parallel robot

2018 ◽  
Vol 35 (8) ◽  
pp. 2775-2801 ◽  
Author(s):  
Fabian Andres Lara-Molina ◽  
Didier Dumur ◽  
Karina Assolari Takano
Keyword(s):  
Optimal Design ◽  
Position Control ◽  
Structural Parameters ◽  
Design Procedure ◽  
Parallel Robot ◽  
Performance Criteria ◽  
Design Criteria ◽  
Flexible Joints ◽  
Content Type ◽  
Multi Objective

Purpose This paper aims to present the optimal design procedure of a symmetrical 2-DOF parallel planar robot with flexible joints by considering several performance criteria based on the workspace size, dynamic dexterity and energy of the control. Design/methodology/approach Consequently, the optimal design consists in determining the dimensional parameters to maximize the size of the workspace, maximize the dynamic dexterity and minimize the energy of the control action. The design criteria are derived from the kinematics, dynamics, elastodynamics and the position control law of the robot. The analysis of the design criteria is performed by means of the design space and atlases. Findings Finally, the multi-objective design optimization derived from the optimal design procedure is solved by using multi-objective genetic algorithms, and the results are analyzed to assess the validity of the proposed approach. Originality/value An alternative approach to the design of a planar parallel robot with flexible joints that permits determining the structural parameters by considering kinematic, dynamic and control operational performance.

Multi-objective optimization of parametric combination of injected slub yarn for producing knitted and woven fabrics with least abrasive damage

2017 ◽  
Vol 21 (2) ◽  
pp. 111-133 ◽  
Author(s):  
Arunangshu Mukhopadhyay ◽  
Vinay Kumar Midha ◽  
Nemai Chandra Ray
Keyword(s):  
Structural Parameters ◽  
Research Work ◽  
Optimal Solution ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Content Type ◽  
Multi Objective ◽  
Score Analysis ◽  
The Impact ◽  
Slub Yarn

Purpose This study aims to optimize the parametric combination of injected slub yarn to achieve least abrasive damage on fabrics produced from it. Design/methodology/approach Single base injected slub yarn structural parameters, vis-à-vis slub length, slub thickness and slub frequency, were varied during preparation of yarn samples under this research work. A total of 17 yarn samples were produced according to the Box and Bhenken design of the experiment. Subsequently knitted and woven (using injected slub yarns in the weft only) fabric samples were prepared from these yarns. Yarn and fabric samples were abraded with standard instruments to see the impact of yarn structural parameters on abrasive damage of fabric in terms of fabric mass loss and appearance deterioration. From the test results, empirical models relating to slub parameters and fabric abrasion behavior were developed through a backward elimination regression approach. Subsequently, a set of optimal parametric combinations was derived with multi-objective evolutionary algorithms by using MATLAB software. This was followed by ranking all optimal solutions through technique for order preference by similarity to idle solution (TOPSIS) score analysis. Findings The injected slub yarn’s structural parameters have a strong influence on the abrasive damage of knitted and woven fabric. It is seen that the best suitable parametric combination of slub parameters for achieving the least abrasive damage is not the same for knitted and woven fabric. Practical implications The spinner can explore this concept to find out the best suitable parametric combination during pattern making of injected slub yarn through MATLAB solution followed by TOPSIS score analysis based on their priority of criteria level to ensure better abrasion behavior of fabric produced. Originality/value Optimization of parametric combination of injected slub yarns will help to ensure production of fabric with most resistance to abrasion for specific applications. The studies showed that the optimal solution for woven and knitted fabrics is different. The result indicates that in the case of knitted fabric, comparatively lesser slub thickness is found to be suitable for getting better fabric abrasion resistance, whereas in the case of woven fabric, comparatively higher slub thickness is found suitable for the same.

Optimal Design of a Micro Series Elastic Actuator

2010 ◽  
Author(s):  
Ozan Tokatli ◽  
Volkan Patoglu
Keyword(s):  
Optimal Design ◽  
Force Control ◽  
Pareto Front ◽  
Position Control ◽  
Compliant Mechanism ◽  
Tracking Error ◽  
Movement Direction ◽  
Design Criteria ◽  
Coupling Element ◽  
Series Elastic

We propose using series elastic actuation (SEA) in micro mechanical devices to achieve precise control of the interaction forces. Using μSEA for force control removes the need for high-precision force sensors/actuators and allows for accurate force control through simple position control of the deflection of a compliant coupling element. Since the performance of a μSEA is highly dependent on the design of this compliant coupling element, we employ a design optimization framework to design this element. In particular, we propose a compliant, under-actuated half-pantograph mechanism as a feasible kinematic structure for this coupling element. Then, we consider multiple design objectives to optimize the performance of this compliant mechanism through dimensional synthesis, formulating an optimization problem to study the trade-offs between these design criteria. We optimize the directional manipulability of the mechanism, simultaneously with its task space stiffness, using a Pareto-front based framework. We select an optimal design by studying solutions on the Pareto-front curve and considering the linearity of the stiffness along the actuation direction as a secondary design criteria. The optimized mechanism possesses high manipulability and low stiffness along the movement direction of the actuator; hence, achieves a large stroke with high force resolution. At the same time, the mechanism has low manipulability and high stiffness along the direction perpendicular to the actuator motion, ensuring good disturbance rejection characteristics. We model the behavior of this compliant mechanism and utilize this model to synthesize a controller for μSEA to study its dynamic response. Simulated closed loop performance of the μSEA with optimized coupling element indicates that force references can be tracked without significant overshoot and with low tracking error (about 1.1%) even for periodic reference signals.

scholarly journals Finding the optimal design of a passive microfluidic mixer

Lab on a Chip ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 3618-3627 ◽  
Author(s):  
Junchao Wang ◽  
Naiyin Zhang ◽  
Jin Chen ◽  
Victor G. J. Rodgers ◽  
Philip Brisk ◽  
...  
Keyword(s):  
Genetic Algorithm ◽  
Optimal Design ◽  
Design Criteria ◽  
Microfluidic Mixer ◽  
Multi Objective ◽  
Multi Objective Genetic Algorithm

Find an optimal design and establish the design criteria of a passive microfluidic mixer using a multi-objective genetic algorithm.

Damage identification using combined acceleration and voltage matching with one-dimensional PZT patch model

2018 ◽  
Vol 14 (1) ◽  
pp. 40-64
Author(s):  
K. Shankar ◽  
N. Jinesh
Keyword(s):  
Structural Parameters ◽  
Optimization Technique ◽  
Crack Identification ◽  
Structural Parameter ◽  
Multiple Cracks ◽  
Content Type ◽  
Patch Model ◽  
One Dimensional ◽  
Multi Objective ◽  
Fixed Beam

Purpose The purpose of this paper is to provide an effective and simple technique for structural parameter identification, particularly to identify multiple cracks in a structure using simultaneous measurement of acceleration responses and voltage signals from PZT patches which is a multidisciplinary approach. A hybrid element constituted of one-dimensional beam element and a PZT sensor is used with reduced material properties which is very convenient for beams and is a novel application for inverse problems. Design/methodology/approach Multi-objective formulation is used whereby structural parameters are identified by minimizing the deviation between the predicted and measured values from the PZT patch and acceleration responses, when subjected to excitation. In the proposed method, a patch is attached to either end of the fixed beam. Using particle swarm optimization algorithm, normalized fitness functions are defined for both voltage and acceleration components with weighted aggregation multi-objective optimization technique. The signals are polluted with 5 percent Gaussian noise to simulate experimental noise. The effects of various weighting factors for the combined objective function are studied. The scheme is also experimentally validated by identification of cracks in a fixed-fixed beam. Findings The numerical and experimental results shows that significant improvement in accuracy of damage detection is achieved by the combined multidisciplinary method, when compared with only voltage or only acceleration-matching method as well as with other methods. Originality/value The proposed multidisciplinary crack identification approach, which is based on one-dimensional PZT patch model as well as conventional acceleration method, is not reported in the literature.

Structure Optimal Design of Pneumatic 6-DOF Parallel Robot Based on Natural Frequency

2010 ◽  
Vol 450 ◽  
pp. 349-352 ◽  
Author(s):  
Bo Wu ◽  
Li Xu ◽  
Xiao Dong Yu ◽  
Zhi Wei Wang ◽  
He Xu
Keyword(s):  
Mathematical Model ◽  
Optimal Design ◽  
Natural Frequency ◽  
Dynamic Equation ◽  
Structural Design ◽  
Optimization Design ◽  
Structural Parameters ◽  
Parallel Robot ◽  
Optimization Rule ◽  
Design Aspect

. In order to improve the dynamic response rapidity and positioning precision for pneumatic 6-DOF parallel robot from the structural design aspect, a mathematical model of natural frequency for the parallel robot is developed based on dynamic equation by using vibration theory. The influences of structural parameters on minimal natural frequency are analyzed by simulation and an optimization rule of structural parameters based on minimal natural frequency is proposed. The optimization rule has advantages of simplification and efficiency, which provides a new theoretical gist for optimization of structural parameters as well as for checking the results of the actual natural frequency for pneumatic 6-DOF parallel robot. And this new rule is also valuable for structural optimization design of other similar parallel robot.

Patch size setup and performance/cost trade-offs in multi-objective EM-driven antenna optimization using sequential domain patching

2017 ◽  
Vol 34 (4) ◽  
pp. 1070-1081
Author(s):  
Slawomir Koziel ◽  
Adrian Bekasiewicz
Keyword(s):  
Control Parameter ◽  
Computational Cost ◽  
Design Procedure ◽  
Simulation Models ◽  
Multi Objective Optimization ◽  
Computationally Efficient ◽  
Content Type ◽  
Multi Objective ◽  
Trade Offs ◽  
And Performance

Purpose This paper aims to assess control parameter setup and its effect on computational cost and performance of deterministic procedures for multi-objective design optimization of expensive simulation models of antenna structures. Design/methodology/approach A deterministic algorithm for cost-efficient multi-objective optimization of antenna structures has been assessed. The algorithm constructs a patch connecting extreme Pareto-optimal designs (obtained by means of separate single-objective optimization runs). Its performance (both cost- and quality-wise) depends on the dimensions of the so-called patch, an elementary region being relocated in the course of the optimization process. The cost/performance trade-offs are studied using two examples of ultra-wideband antenna structures and the optimization results are compared to draw conclusions concerning the algorithm robustness and determine the most advantageous control parameter setups. Findings The obtained results indicate that the investigated algorithm is very robust, i.e. its performance is weakly dependent on the control parameters setup. At the same time, it is found that the most suitable setups are those that ensure low computational cost, specifically non-uniform ones generated on the basis of sensitivity analysis. Research limitations/implications The study provides recommendations for control parameter setup of deterministic multi-objective optimization procedure for computationally efficient design of antenna structures. This is the first study of this kind for this particular design procedure, which confirms its robustness and determines the most suitable arrangement of the control parameters. Consequently, the presented results permit full automation of the surrogate-assisted multi-objective antenna optimization process while ensuring its lowest possible computational cost. Originality/value The work is the first comprehensive validation of the sequential domain patching algorithm under various scenarios of its control parameter setup. The considered design procedure along with the recommended parameter arrangement is a robust and computationally efficient tool for fully automated multi-objective optimization of expensive simulation models of contemporary antenna structures.

An optimization tool for coaxial magnetic gears

2017 ◽  
Vol 36 (5) ◽  
pp. 1526-1539 ◽  
Author(s):  
Mattia Filippini ◽  
Piergiorgio Alotto
Keyword(s):  
Design Procedure ◽  
Design Tool ◽  
Computational Method ◽  
Content Type ◽  
Geometrical Properties ◽  
Multi Objective ◽  
Constrained Problems ◽  
De Algorithm ◽  
Starting Point ◽  
Magnetic Gear

Purpose This paper aims to show a complete optimization tool that can be used for the design of coaxial magnetic gears. In the first part, the paper deals with the semi-analytic modelling of these machines and also discusses how to reduce the computational efforts. In the second part, an optimization algorithm is adopted for finding the Pareto optimal geometries. Design/methodology/approach The machine is subdivided into a set of domains according to their physical and geometrical properties, and the potential distribution is found semi-analytically in them under some simplifying hypothesis. A loss estimation is performed for both ferromagnetic and permanent magnet regions. A stochastic differential evolution (DE) algorithm for multi-objective constrained problems is then applied. Findings It is shown that the presented design tool gives results in accordance to finite element method (FEM)-based analysis keeping the advantages of robustness and simplicity of the analytical methods. The DE-based strategy performs well on the magnetic gear optimization problem. Practical implications The proposed tool appears to be a good starting point when designing coaxial magnetic gears. The optimal Pareto points can be used as initial seeds of FEM-based optimizations, resulting in a cheaper computational method with respect to a full FEM optimization. Originality/value This paper takes inspiration from recent works on magnetic gear modelling and completes the design procedure with a suitable efficiency estimation. The paper also shows how to use mature optimization strategies to solve the constrained multi-objective magnetic gear design problem.

Efficiency optimization of a two-port microwave oven: a robust automated procedure

2015 ◽  
Vol 34 (4) ◽  
pp. 1213-1228 ◽  
Author(s):  
Fernando Bressan ◽  
Fabrizio Dughiero ◽  
Marco Bullo ◽  
Paolo Di Barba
Keyword(s):  
Optimal Design ◽  
High Frequency ◽  
High Efficiency ◽  
Design Procedure ◽  
Field Analysis ◽  
Evolutionary Strategy ◽  
High Frequency Field ◽  
3D Fem ◽  
Content Type ◽  
Frequency Field

Purpose – In the paper, a single-objective optimization problem characterized by high-frequency field analysis is investigated: the optimal design of a two-port microwave (MW) oven, taking into account the possibility of two independently controlled sources, with the aim of improving the efficiency is considered as the case study. The paper aims to discuss these issues. Design/methodology/approach – A high-frequency field analysis has been coupled to a robust evolutionary-computing algorithm in order to create an appropriate procedure for the optimal design of a MW oven based on a cascade optimization: in the first step the optimized geometry has been identified, while in the second step the optimized electrical supply values have been synthesized. In particular, the direct problem has been faced by means of a 3D-FEM approach in order to obtain realistic results; the inverse problem has been faced by means of a derivative-free robust algorithm based on evolutionary strategy in order to get a fast convergence of the solution. Findings – A new design procedure for high efficiency MW ovens for household application by means of the proposed numerical approach. Practical implications – These results allow industrial designers to improve this kind of devices. Originality/value – The original contribution of the paper is the systematic approach to the optimal design of a MW oven with multiple feeding, based on the link between an algorithm of evolutionary strategy optimization algorithm and a finite-element solver.

Cuckoo search as a tool for optimal design of PM brushless DC motor

2018 ◽  
Vol 37 (5) ◽  
pp. 1732-1743 ◽  
Author(s):  
Goga Vladimir Cvetkovski ◽  
Lidija Petkovska ◽  
Paul Lefley
Keyword(s):  
Comparative Analysis ◽  
Optimal Design ◽  
Research Work ◽  
Design Procedure ◽  
Cuckoo Search ◽  
Electrical Machines ◽  
Brushless Dc Motor ◽  
Content Type ◽  
Brushless Dc

Purpose The purpose of this paper is to perform an optimal design of a single-phase permanent magnet brushless DC motor (SPBLDCM) by using efficiency of the motor as an objective function. In the design procedure of the motor, a cuckoo search (CS) algorithm is used as an optimization tool. Design/methodology/approach For the purpose of this research work, a computer program for optimal design of electrical machines based on the CS optimization has been developed. Based on the design characteristics of SPBLDCM, some of the motor parameters are chosen to be constant and others variable. A comparative analysis of the initial motor model and the CS model based on the value of the objective function, as well as the values of the optimization parameters, is performed and presented. Findings Based on the comparative data analysis of both motor models, it can be concluded that the main objective of the optimization is realized, and it is achieved by an improvement of the efficiency of the motor. Practical implications The optimal design approach of SPBLDCM presented in this research work can be also implemented on other electrical machines and devices using the same or even other objective functions. Originality/value An optimization technique using CS as an optimization tool has been developed and applied in the design procedure of SPBLDCM. According to the results, it can be concluded that the CS algorithm is a suitable tool for design optimization of SPBLDCM and electromagnetic devices in general. The quality of the CS model has been proved through the data analysis of the initial and optimized solution. The quality of the CS solution has been also proved by comparative analysis of the two motor models using FEM as a performance analysis tool.

Multi-Objective optimal design of a cable driven parallel robot for rehabilitation tasks

2021 ◽  
Vol 156 ◽  
pp. 104141
Author(s):  
Ines Ben Hamida ◽  
Med Amine Laribi ◽  
Abdelfattah Mlika ◽  
Lotfi Romdhane ◽  
Saïd Zeghloul ◽  
...  
Keyword(s):  
Optimal Design ◽  
Parallel Robot ◽  
Multi Objective ◽  
Rehabilitation Tasks
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