Hybrid (Symbolic-Numerical) Optimization in Mechanism Design for the Elimination of Redundant Constraints

1991 ◽  
Vol 113 (2) ◽  
pp. 110-123 ◽  
Author(s):  
D. A. Hoeltzel ◽  
Wei-Hua Chieng
Keyword(s):  
Design Optimization ◽  
Numerical Optimization ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
Systematic Approach ◽  
Hybrid Design ◽  
New Approach ◽  
Symbolic Reasoning ◽  
Algorithmic Analysis ◽  
Programming Algorithms

Hybrid optimization, a new approach to design optimization employing both symbolic reasoning and algorithmic analysis, has been applied to the design of kinematic pairs in mechanisms. This hybrid design methodology provides a three-step systematic approach for (1) combining the degrees-of-freedom found in simple, lower kinematic pairs to obtain more complex but robust higher pairs, (2) judging inappropriately assigned joints for the elimination of redundant kinematic constraints and harmful mobilities, and (3) assisting nonexpert designers in applying nonlinear programming algorithms for detailed numerical design optimization of kinematic pairs. An example taken from the design of a spatial mechanism, specifically a universal joint, is presented and serves to demonstrate the utility of this procedure for detailed hybrid design optimization of kinematic pairs in mechanisms.

An Optimization Approach Toward a Robust Design of Six Degrees of Freedom Haptic Devices

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Aftab Ahmad ◽  
Kjell Andersson ◽  
Ulf Sellgren
Keyword(s):  
Design Optimization ◽  
Robust Design ◽  
Degrees Of Freedom ◽  
Design Parameters ◽  
Manufacturing Cost ◽  
Optimization Approach ◽  
Performance Indices ◽  
New Approach ◽  
Haptic Devices ◽  
Six Degrees Of Freedom

This work presents an optimization approach for the robust design of six degrees of freedom (DOF) haptic devices. Our objective is to find the optimal values for a set of design parameters that maximize the kinematic, dynamic, and kinetostatic performances of a 6-DOF haptic device while minimizing its sensitivity to variations in manufacturing tolerances. Because performance indices differ in magnitude, the formulation of an objective function for multicriteria performance requirements is complex. A new approach based on Monte Carlo simulation (MCS) was used to find the extreme values (minimum and maximum) of the performance indices to enable normalization of these indices. The optimization approach presented here is formulated as a methodology in which a hybrid design-optimization approach, combining genetic algorithm (GA) and MCS, is first used. This new approach can find the numerical values of the design parameters that are both optimal and robust (i.e., less sensitive to variation and thus to uncertainties in the design parameters). In the following step, with design optimization, a set of optimum tolerances is determined that minimizes manufacturing cost and also satisfies the allowed variations in the performance indices. The presented approach can thus enable the designer to evaluate trade-offs between allowed performance variations and tolerances cost.

Mono and bi-Level optimization architectures for powertrain design

2016 ◽  
Vol 35 (3) ◽  
Author(s):  
Pierre Caillard ◽  
Frederic Gillon ◽  
Sid-Ali Randi ◽  
Noelle Janiaud
Keyword(s):  
Optimal Design ◽  
Design Optimization ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
Computing Time ◽  
Computational Cost ◽  
New Guidelines ◽  
Electric Machine Control ◽  
Optimization Loop ◽  
Electric Powertrains

Purpose The purpose of this paper is to compare two design optimization architectures for the optimal design of a complex device that integrates simultaneously the sizing of system components and the control strategy for increasing the energetic performances. The considered benchmark is a battery electric passenger car. Design/methodology/approach The optimal design of an electric vehicle powertrain is addressed within this paper, with regards to performances and range. The objectives and constraints require simulating several vehicle operating points, each of them has one degree of freedom for the electric machine control. This control is usually determined separately for each point with a sampling or an optimization loop resulting in an architecture called bi-level. In some conditions, the control variables can be transferred to the design optimization loop by suppressing the inner loop to get a mono-level formulation. The paper describes in which conditions this transformation can be done and compares the results for both architectures. Findings Results show a calculation time divided by more than 30 for the mono-level architecture compared to the natural bi-level on the study case. Even with the same models and optimization algorithms, the structure of the problem should be studied to improve the results, especially if computational cost is high. Originality/value The compared architectures bring new guidelines in the field optimal design for electric powertrains. The way to formulate a design optimization with some inner degrees of freedom can have a significant impact on computing time and on the problem understanding

A Function Based Approach to TRIZ

2011 ◽  
Author(s):  
Anthony A. Nix ◽  
Ben Sherrett ◽  
Robert B. Stone
Keyword(s):  
Problem Solving ◽  
Design Methodology ◽  
Systematic Approach ◽  
Hybrid Design ◽  
Functional Design ◽  
Functional Modeling ◽  
Design Problems ◽  
Functional Basis ◽  
Creative Solutions

Function based design methods — those that are largely a derivative of Pahl and Beitz’s systematic approach — are a powerful tool employed in a variety of engineering design contexts. However, many other design methodologies exist and are useful in solving design problems. These methods include varying approaches from Suh’s Axiomatic Design to Altshuller’s Theory of Inventive Problem Solving (TIPS or TRIZ) to the business-motivated Ulwick’s Outcome Driven Method. In this paper an attempt to merge the philosophy of functional design with the problem solving approach of TRIZ is undertaken. A framework is proposed combining functional modeling formalized by the Functional Basis with TRIZ. The process of merging the two methodologies is presented along with the key contribution, a matrix that relates the vocabulary of the Functional Basis with the 40 inventive principles of TRIZ. The use of the Functional Basis-TRIZ (FB-TRIZ) hybrid design methodology is described and a case study is presented demonstrating its use as well as the creative solutions that the approach affords.

DEVELOPMENT OF PRINCIPLES FOR THE DESIGN OF COMPLEX TECHNICAL MEANS AND TECHNOLOGICAL PROCESSES OF CROP PRODUCTION

1970 ◽  
pp. 70-72
Author(s):  
D. N. Radnaev ◽  
Yu. А. Sergeev ◽  
А. А. Abiduev ◽  
S. V. Petunov
Keyword(s):  
Crop Production ◽  
Design Methodology ◽  
Systematic Approach ◽  
Optimal Solution ◽  
Agricultural Science ◽  
Complex Objects ◽  
Technological Processes ◽  
Methods Of Synthesis ◽  
Working Bodies ◽  
Projected Process

Currently, agricultural science and practice has a large amount of experimental data that need to be taken into account in the development of new technological processes and working bodies. Therefore, there is a need to design technical processes in order to identify their effectiveness. In this regard, the use of methods of synthesis of technological processes based on the characteristics of tillage, seeding and production system of the economy, in which it is necessary to implement the projected process. In the General statement of the problem, the design of technological processes is one of the complex problems with the following characteristic feature: lack of knowledge about the methods of designing technological processes, suitable for system - structural modeling and algorithmization of design processes. To overcome this incompleteness, a systematic approach is needed. The system approach proceeds from the fact that the specificity of complex objects and processes is not limited to the features of its constituent parts and elements, but lies in the nature of relationships and relationships between them. In this paper, the design methodology is based on the formulated fundamental assumptions and principles of the whole system of more specific statements, revealing the structure and content of design operations, the synthesis of the choice of solutions. The principles of technological compatibility and emergence suitable for system-structural analysis of complex technical means and technological processes, consisting of statements having a hierarchical structure, where the degree of detail of the goals from level to level increases, and the approval of the last level determines the direction of the search for the optimal solution to the problem.

scholarly journals Hybrid Seven-bar Press Mechanism

2018 ◽  
Vol 12 (3) ◽  
pp. 181-187
Author(s):  
M. Erkan Kütük ◽  
L. Canan Dülger
Keyword(s):  
Genetic Algorithm ◽  
Objective Function ◽  
Design Optimization ◽  
Hybrid System ◽  
Degrees Of Freedom ◽  
Dimensional Synthesis ◽  
Design Variables ◽  
Optimization Study ◽  
Metal Stamping

An optimization study with kinetostatic analysis is performed on hybrid seven-bar press mechanism. This study is based on previous studies performed on planar hybrid seven-bar linkage. Dimensional synthesis is performed, and optimum link lengths for the mechanism are found. Optimization study is performed by using genetic algorithm (GA). Genetic Algorithm Toolbox is used with Optimization Toolbox in MATLAB®. The design variables and the constraints are used during design optimization. The objective function is determined and eight precision points are used. A seven-bar linkage system with two degrees of freedom is chosen as an example. Metal stamping operation with a dwell is taken as the case study. Having completed optimization, the kinetostatic analysis is performed. All forces on the links and the crank torques are calculated on the hybrid system with the optimized link lengths

scholarly journals A New Approach of Soft Joint Based on a Cable-Driven Parallel Mechanism for Robotic Applications

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1468
Author(s):  
Luis Nagua ◽  
Carlos Relaño ◽  
Concepción A. Monje ◽  
Carlos Balaguer
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Experimental Tests ◽  
Humanoid Robots ◽  
Inverse Kinematic ◽  
Element Analysis ◽  
New Approach ◽  
Flexible Polymer ◽  
The Mathematical Model

A soft joint has been designed and modeled to perform as a robotic joint with 2 Degrees of Freedom (DOF) (inclination and orientation). The joint actuation is based on a Cable-Driven Parallel Mechanism (CDPM). To study its performance in more detail, a test platform has been developed using components that can be manufactured in a 3D printer using a flexible polymer. The mathematical model of the kinematics of the soft joint is developed, which includes a blocking mechanism and the morphology workspace. The model is validated using Finite Element Analysis (FEA) (CAD software). Experimental tests are performed to validate the inverse kinematic model and to show the potential use of the prototype in robotic platforms such as manipulators and humanoid robots.

scholarly journals The concept of neutrality: a new approach

2019 ◽  
Vol 76 (1) ◽  
pp. 333-353 ◽  
Author(s):  
Stephen Macdonald ◽  
Briony Birdi
Keyword(s):  
Literature Review ◽  
Design Methodology ◽  
Information Science ◽  
Social Institutions ◽  
Future Research ◽  
Library And Information Science ◽  
New Approach ◽  
Content Type ◽  
Normative Framework ◽  
Contextual Awareness

Purpose Neutrality is a much debated value in library and information science (LIS). The “neutrality debate” is characterised by opinionated discussions in contrasting contexts. The purpose of this paper is to fill a gap in the literature by bringing these conceptions together holistically, with potential to deepen understanding of LIS neutrality. Design/methodology/approach First, a literature review identified conceptions of neutrality reported in the LIS literature. Second, seven phenomenographic interviews with LIS professionals were conducted across three professional sectors. To maximise variation, each sector comprised at least one interview with a professional of five or fewer years’ experience and one with ten or more years’ experience. Third, conceptions from the literature and interviews were compared for similarities and disparities. Findings In four conceptions, each were found in the literature and interviews. In the literature, these were labelled: “favourable”, “tacit value”, “social institutions” and “value-laden profession”, whilst in interviews they were labelled: “core value”, “subservient”, “ambivalent”, and “hidden values”. The study’s main finding notes the “ambivalent” conception in interviews is not captured by a largely polarised literature, which oversimplifies neutrality’s complexity. To accommodate this complexity, it is suggested that future research should look to reconcile perceptions from either side of the “neutral non-neutral divide” through an inclusive normative framework. Originality/value This study’s value lies in its descriptive methodology, which brings LIS neutrality together in a holistic framework. This framework brings a contextual awareness to LIS neutrality lacking in previous research. This awareness has the potential to change the tone of the LIS neutrality debate.

Development of insect repellent finish by a simple coacervation microencapsulation technique

2018 ◽  
Vol 30 (2) ◽  
pp. 152-158 ◽  
Author(s):  
Rachna Sharma ◽  
Alka Goel
Keyword(s):  
Essential Oils ◽  
Design Methodology ◽  
Insect Repellent ◽  
New Approach ◽  
Content Type ◽  
Eucalyptus Oil ◽  
Gum Acacia ◽  
Major Benefit ◽  
Natural Insecticide ◽  
Practical Implications

Purpose The paper focused onto the development of microcapsules by using two essential oils. It proposes the uses of eucalyptus oil and cedarwood oil as a natural insecticide. The purpose of this paper is to demonstrate the application of developed microcapsules to impart insect repellency on textile substrate. Design/methodology/approach The paper opted for an experimental study using two essential oils and gum in formations of microcapsules through a simple coaseravtion encapsulation technique. The developed solution was analyzed, including confirmation of size and structure through. Application of developed finish on substrate was also undertaken to prove better ability as repellent fabric. Findings The paper highlights useful invention of microencapsulated fabric developed with the combination of gum acacia and eucalyptus oil as core and shell material. The developed fabric has better ability to repel silverfish as compared to microencapsulated fabric developed with gum acacia (shell) and cedarwood oil (core). Research limitations/implications Due to the lack of time and less availability of essential oils, only two oils were used to test the insect repellent behavior. Practical implications This paper fulfills an identified need, it includes implications for the development of a very useful natural insecticide to repel silverfish (Lepisma saccharina) insect. This insect is a very common problem found in cloth wardrobes and bookshelves; it mainly attacks the fabric with cellulosic content and starch. Social implications Society will get major benefit of using these microencapsulated finished fabrics, which repel silverfish from their home and keep their clothing and books safe for longer period. The natural fragrance and medicinal benefits of these essential oils can never be ignored. Originality/value This study sets a new approach to repel insects like silverfish from the bookshelves and clothing wardrobes. A layer of insect repellent microencapsulated finished fabric can be added in these shelves and wardrobes. It is an eco-friendly approach of using natural essential oils instead of chemical insecticides.

Analysis and Optimization of a New Differentially Driven Cable Parallel Robot

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Hamed Khakpour ◽  
Lionel Birglen ◽  
Souheil-Antoine Tahan
Keyword(s):  
Kinematic Analysis ◽  
Design Methodology ◽  
Degrees Of Freedom ◽  
Parallel Robot ◽  
Cable Robot ◽  
Proper Design ◽  
Two Indices ◽  
Three Degrees Of Freedom ◽  
Cable Robots

In this paper, a new three degrees of freedom (DOF) differentially actuated cable parallel robot is proposed. This mechanism is driven by a prismatic actuator and three cable differentials. Through this design, the idea of using differentials in the structure of a spatial cable robot is investigated. Considering their particular properties, the kinematic analysis of the robot is presented. Then, two indices are defined to evaluate the workspaces of the robot. Using these indices, the robot is subsequently optimized. Finally, the performance of the optimized differentially driven robot is compared with fully actuated mechanisms. The results show that through a proper design methodology, the robot can have a larger workspace and better performance using differentials than the fully driven cable robots using the same number of actuators.

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