Multi-objective optimal design based kineto-elastostatic performance for thedeltaparallel mechanism

Robotica ◽  
2014 ◽  
Vol 34 (2) ◽  
pp. 258-273 ◽  
Author(s):  
Belkacem Bounab
Keyword(s):  
Performance Optimization ◽  
Design Problem ◽  
Design Method ◽  
Design Procedure ◽  
Parallel Robot ◽  
Simultaneous Optimization ◽  
Dimensional Synthesis ◽  
Multi Objective ◽  
Trade Offs ◽  
And Control

SUMMARYThis paper addresses the dimensional-synthesis-based kineto-elastostatic performance optimization of thedeltaparallel mechanism. For the manipulator studied here, the main consideration for the optimization criteria is to find the maximum regular workspace where the robotdeltamust posses high stiffness and dexterity. The dexterity is a kinetostatic quality measure that is related to joint's stiffness and control accuracy. In this study, we use the Castigliano's energetic theorem for modeling the elastostatic behavior of thedeltaparallel robot, which can be evaluated by the mechanism's response to external applied wrench under static equilibrium. In the proposed formulation of the design problem, global structure's stiffness and global dexterity are considered together for the simultaneous optimization. Therefore, we formulate the design problem as a multi-objective optimization one and, we use evolutionary genetic algorithms to find all possible trade-offs among multiple cost functions that conflict with each other. The proposed design procedure is developed through the implementation of thedeltarobot and, numerical results show the effectiveness of the proposed design method to enhancing kineto-elastostatic performance of the studied manipulator's structure.

An optimum synthesis for gripping mechanisms by using natural coordinates

2002 ◽  
Vol 216 (6) ◽  
pp. 643-653 ◽  
Author(s):  
M Ceccarelli ◽  
J Cuadrado ◽  
D Dopico
Keyword(s):  
Design Problem ◽  
Optimization Design ◽  
Design Method ◽  
Design Procedure ◽  
Natural Coordinates ◽  
Dimensional Synthesis ◽  
Efficient Procedure ◽  
Optimum Synthesis ◽  
Practical Design ◽  
Design Requirements

In this paper a simple and efficient procedure for optimum dimensional synthesis of gripping mechanisms is presented. The proposed design method is based on a suitable formulation of grasping performance of gripping mechanisms and makes use of a description of mechanisms by means of natural (fully Cartesian) coordinates. The optimization design problem is formulated by an objective function describing the main grasping performance and constraints prescribing practical design requirements and mechanism peculiarities. A numerical example is reported and discussed to illustrate the engineering feasibility of the proposed design procedure.

Multi Mode Vibration Control and Broder Band Motion Control of Three Dimensional Shaking Table

2005 ◽  
Author(s):  
Tsunehiro Wakasugi ◽  
Toru Watanabe ◽  
Kazuto Seto
Keyword(s):  
Vibration Control ◽  
Controller Design ◽  
Design Method ◽  
Three Dimensional ◽  
Design Procedure ◽  
Equation System ◽  
State Equation ◽  
Shaking Table ◽  
Mode Vibration ◽  
And Control

This paper deals with a new system design method for motion and vibration control of a three-dimensional flexible shaking table. An integrated modeling and controller design procedure for flexible shaking table system is presented. An experimental three-dimensional shaking table is built. “Reduced-Order Physical Model” procedure is adopted. A state equation system model is composed and a feedback controller is designed by applying LQI control law to achieve simultaneous motion and vibration control. Adding a feedforward, two-degree-of-freedom control system is designed. Computer simulations and control experiments are carried out and the effectiveness of the presented procedure is investigated. The robustness of the system is also investigated.

GA-BASED DESIGN OF 2D STATE-SPACE DIGITAL FILTERS WITH LINEAR PHASE CHARACTERISTICS

2007 ◽  
Vol 16 (02) ◽  
pp. 287-303 ◽  
Author(s):  
SANG-CHURL NAM ◽  
MASAHIDE ABE ◽  
MASAYUKI KAWAMATA
Keyword(s):  
State Space ◽  
Design Problem ◽  
Digital Filters ◽  
Design Method ◽  
Design Procedure ◽  
Gray Code ◽  
Superior Performance ◽  
Magnitude Response ◽  
The Stability ◽  
Group Delays

This paper proposes a GA-based design method for two-dimensional (2D) state-space digital filters which satisfy simultaneously the magnitude response and constant group delays. The design problem of 2D state-space digital filters is formulated subject to the constraint that the resultant filters are stable. To apply the genetic algorithm to the design problem, all coefficients of 2D state-space digital filters are encoded into the Gray code representation demonstrating the superior performance to the standard binary one. In addition, a stability test routine is embedded in the design procedure in order to ensure the stability for the resultant filters. A numerical example is given to demonstrate the effectiveness of the proposed method.

Research on Design Method of Combined Steel Lead Energy Dissipation Structure

2011 ◽  
Vol 71-78 ◽  
pp. 526-530
Author(s):  
Xue Yuan Yan ◽  
Ai Qi ◽  
Wei Lin ◽  
Su Guo Wang
Keyword(s):  
Energy Dissipation ◽  
Design Method ◽  
Design Procedure ◽  
Hysteresis Loops ◽  
Shaking Table ◽  
Static Tests ◽  
Dissipation Structure ◽  
Hydraulic Servo ◽  
Control Principle ◽  
And Control

Construction and control principle of the new combined steel lead damper (NCSLD) were introduced, pseudo-static tests of NCSLD which would be used in the subsequent shaking table tests were carried out for the study of its mechanical properties using electro-hydraulic servo press-shear machine. Structural seismic design procedure using NCSLD is presented. An engineering example of seismic strengthening using NCSLD is provided. Results of tests and analyses indicate that NCSLD has full hysteresis loops which take on bilinearity; NCSLD is of strong energy dissipation ability and has obvious control effects for structural inter-story displacement and acceleration reactions.

A Combined Plant/Controller Optimization Framework for Hybrid Vehicles With MPG, Emissions and Drivability Considerations

2016 ◽  
Author(s):  
Huckleberry Febbo ◽  
Tulga Ersal ◽  
Jeffrey L. Stein
Keyword(s):  
Hybrid Electric Vehicle ◽  
Optimization Problem ◽  
Design Procedure ◽  
Design Tool ◽  
Optimized Design ◽  
Optimization Strategy ◽  
Meta Model ◽  
Design Methodologies ◽  
Trade Offs ◽  
And Control

The design and control of hybrid-electric vehicle (HEV) powertrains presents an optimization problem to balance the trade-off between multiple objectives, such as fuel economy, driv-ability, and emissions. However, current design methodologies do not simultaneously incorporate all of these three considerations into both the sizing and control layers of the optimization problem. This paper first demonstrates that the trade-offs between these objectives can be non-trivial in the HEV control problem. This motivates the need for a systematic design procedure that can take all three objectives into account. To address this need, the paper describes the development of a new and efficient design framework called the Hybrid-Vehicle Design Tool (HVDT), which adopts a bi-level optimization strategy. Efficiency is achieved by introducing a neural-network-based meta-model to predict the performance of the optimal control strategy obtained using Dynamic Programming (DP). To demonstrate the HVDT, a small HEV is designed for the UDDS and HWFET driving cycles separately. Results show that the optimized design can reduce fuel consumption, improve emissions and improve driv-ability when compared to the nominal design obtained using first principle design methodologies. Additionally, compared to using DP directly in the bi-level optimization, using the meta-model reduces the simulation from 238 to 16 days (93%) and from 132 to 16 days (88%) for the UDDS and HWFET cycles, respectively, with an acceptable compromise in the accuracy of predicting the performance of DP.

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.

scholarly journals Robust Aerodynamic Design of Nacelles for Future Civil Aero-Engines

2020 ◽  
Author(s):  
B. Deneys J. Schreiner ◽  
Fernando Tejero ◽  
David G. MacManus ◽  
Christopher Sheaf
Keyword(s):  
Design Method ◽  
Operating Conditions ◽  
Propulsive Efficiency ◽  
Multi Objective ◽  
Fuel Burn ◽  
Trade Offs ◽  
Specific Thrust ◽  
Aero Engines ◽  
The Impact ◽  
Bypass Ratio

Abstract As the growth of aviation continues it is necessary to minimise the impact on the environment, through reducing NOx emissions, fuel-burn and noise. In order to achieve these goals, the next generation of Ultra-High Bypass Ratio engines are expected to increase propulsive efficiency through operating at reduced specific thrust. Consequently, there is an expected increase in fan diameter and the associated potential penalties of nacelle drag and weight. In order to ensure that these penalties do not negate the benefits obtained from the new engine cycles, it is envisaged that future civil aero-engines will be mounted in compact nacelles. While nacelle design has traditionally been tackled by multi-objective optimisation at different flight conditions within the cruise segment, it is anticipated that compact configurations will present larger sensitivity to off-design conditions. Therefore, a design method that considers the different operating conditions that are met within the full flight envelope is required for the new nacelle design challenge. The method is employed to carry out multi-point multi-objective optimisation of axisymmetric aero-lines at different transonic and subsonic operating conditions. It considers mid-cruise conditions, end-of-cruise conditions, the sensitivity to changes in flight Mach number, windmilling conditions with a cruise engine-out case and an engine-out diversion scenario. Optimisation routines were conducted for a conventional nacelle and a future aero-engine architecture, upon which the aerodynamic trade-offs between the different flight conditions are discussed. Subsequently, the tool has been employed to identify the viable nacelle design space for future compact civil aero-engines for a range of nacelle lengths.

scholarly journals Applications of Multi-Objective Optimization to Industrial Processes: A Literature Review

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 133
Author(s):  
Sandra C. Cerda-Flores ◽  
Arturo A. Rojas-Punzo ◽  
Fabricio Nápoles-Rivera
Keyword(s):  
Literature Review ◽  
System Performance ◽  
Industrial Processes ◽  
Multi Objective Optimization ◽  
Future Perspectives ◽  
Multi Objective ◽  
Synthesis Design ◽  
Open Questions ◽  
Trade Offs ◽  
And Control

Industrial processes provide several of the products and services required for society. However, each industry faces different challenges from different perspectives, all of which must be reconciled to obtain profitable, productive, controllable, safe and sustainable processes. In this context, multi-objective optimization has become a powerful tool to aid the decision-making mechanism in the synthesis, design, operation and control of such processes. The solution to the mathematical models provides the necessary tools to asses the system performance in terms of different metrics and evaluate the trade-offs between the objectives in conflict. The number of applications of multi- objective optimization in industrial processes is ample and each application has its own challenges. In the present literature review, a broad panorama of the applications in multi-objective optimization is presented, including future perspectives and open questions that still need to be addressed.

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.

Simultaneous Optimization of Impeller Blade Loading Distribution and Meridional Geometry for Aerodynamic Design of Centrifugal Compressor

2019 ◽  
Author(s):  
Kaito Manabe ◽  
Sasuga Ito ◽  
Masato Furukawa ◽  
Kazutoyo Yamada ◽  
Nobuhito Oka ◽  
...  
Keyword(s):  
Viscous Flow ◽  
Design Method ◽  
Flow Analysis ◽  
Design Procedure ◽  
Simultaneous Optimization ◽  
Low Flow ◽  
Aerodynamic Design ◽  
Impeller Blade ◽  
Rate Condition ◽  
Blade Loading

Abstract The present optimum design method has been advanced for simultaneous optimization of impeller blade loading distribution and meridional geometry. This is based on an aerodynamic design method and a genetic algorithm. The aerodynamic design method consists of two parts: a meridional viscous flow analysis and a two-dimensional inverse blade design procedure. In the meridional viscous flow analysis, an axisymmetric viscous flow is numerically analyzed on a two-dimensional grid to determine the flow distribution around the impeller and diffuser. Effects of blades onto the axisymmetric flow field are considered by a blade force modeling. In the inverse blade design procedure, 3-D impeller geometry can be obtained from the result of meridional viscous flow analysis and the predetermined blade loading distribution. In the optimization procedure, the total pressure ratio and adiabatic efficiency obtained from the meridional viscous flow analysis are employed as objective functions. As a constraint of the optimization, mass flux distribution at the impeller trailing edge is introduced in the evaluation procedure, in order to suppress the boundary layer development near the shroud, especially under low flow rate condition. Total performances and three-dimensional flow fields of centrifugal compressors have been analyzed by 3D-RANS simulations to certify effectiveness of the present design method. The 3D-RANS simulations and the flow visualization have been applied to a conventional centrifugal compressor and optimized design cases. From the analysis results, the performance enhancement of optimized designs is confirmed under low flow rate condition including design point. In addition to that, it is revealed that the constraint works effectively on the performance improvement. As a result, construction of the simultaneous optimization using the aerodynamic design method and the genetic algorithm is successfully achieved.

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