Strategies for Topologic and Parametric Rule Application in Automated Design Synthesis Using Graph Grammars

2014 ◽  
Author(s):  
Corinna Königseder ◽  
Kristina Shea
Keyword(s):  
Early Stage ◽  
A Priori ◽  
Computational Design ◽  
Automated Design ◽  
Graph Grammar ◽  
Synthesis Process ◽  
Task Graph ◽  
Graph Grammars ◽  
Design Synthesis ◽  
Objective Function Values

Computational Design Synthesis (CDS) is used to enable the computer to generate valid and even creative solutions for an engineering task. Graph grammars are a CDS approach in which engineering knowledge is formalized using graphs to represent designs and rules that describe possible graph transformations, i.e. changes of designs. For most engineering tasks two different kinds of rules are required: rules that change the topology and rules that change parameters of a design. One of the main challenges in CDS using both topologic and parametric rules is to decide a priori which type of rule to apply in which stage of the synthesis process. The research presented in this paper describes different strategies for the combination of topologic and parametric rules during automated design synthesis. A graph grammar for the design of gearboxes is investigated in which topologic rules change the structure, i.e. the number and connections of gears and shafts, whereas parametric rules change the layout and sizing, i.e. the dimensions and positions of gears and shafts, in the gearbox. For the generation of new designs, two simple multi-objective stochastic search algorithms are used and compared. Four different strategies are presented that determine in different ways which type of rule (topologic or parametric) to apply in which stage of the synthesis process. The presented strategies are compared considering the quantity of the generated designs, i.e. the number of topologically different designs, and their quality, i.e. their objective function values. Results show a significant influence of the chosen strategy only in an early stage of the synthesis process. The discussion examines the adaptability of the proposed strategies to other engineering tasks.

Automated Synthesis of Passive Dynamic Brachiating Robots Using a Simulation-Driven Graph Grammar Method

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Fritz Stöckli ◽  
Kristina Shea
Keyword(s):  
Dynamic Simulation ◽  
Dynamic Systems ◽  
Computational Design ◽  
Automated Design ◽  
Graph Grammar ◽  
Robotic Systems ◽  
Design Synthesis ◽  
Continuous Contact ◽  
Cyclic Motion ◽  
Grammar Rules

Passive dynamic systems have the advantage over conventional robotic systems that they do not require actuators and control. Brachiating, in particular, involves the swinging motion of an animal from one branch to the next. Such systems are usually designed manually by human designers and often are bio-inspired. However, a computational design approach has the capability to search vast design spaces and find solutions that go beyond those possible by manual design. This paper addresses the automated design of passive dynamic systems by introducing a graph grammar-based method that integrates dynamic simulation to evaluate and evolve configurations. In particular, the method is shown to find different, new solutions to the problem of the design of two-dimensional passive, dynamic, continuous contact, brachiating robots. The presented graph grammar rules preserve symmetry among robot topologies. A separation of parametric multi-objective optimization and topologic synthesis is proposed, considering four objectives: number of successful swings, deviation from cyclic motion, required space, and number of bodies. The results show that multiple solutions with varying complexity are found that trade-off cyclic motion and the space required. Compared to research on automated design synthesis of actuated and controlled robotic systems, this paper contributes a new method for passive dynamic systems that integrates dynamic simulation.

Automated Graph Grammar Generation for Engineering Design With Frequent Pattern Mining

2017 ◽  
Author(s):  
Shraddha Sangelkar ◽  
Daniel A. McAdams
Keyword(s):  
Data Mining ◽  
Pattern Mining ◽  
Computational Design ◽  
Graph Grammar ◽  
Frequent Pattern ◽  
Graph Grammars ◽  
Design Synthesis ◽  
Graph Data ◽  
Grammar Rules ◽  
Computational Design Synthesis

Graph grammars, a technique for formulating new graphs based on a set of rules, is a very powerful tool for computational design synthesis. It is particularly suitable for discrete categorical data where principal component analysis is generally not applicable. Furthermore, this technique utilizes three different programs in conjunction with a design repository, which is opposed to traditional methods that require experts to empirically derive graph grammars. This technique can be separated into three steps. These steps are the creation of the input, graph data mining, and interpretation of the output with the intention of these steps being to automate or assist an expert with the process of extracting engineering graph grammars. Graph grammars that can then serve as guidelines during concept generation. The results of this paper show that this technique is very applicable to computational design synthesis by testing only a small number of products and still producing tangible results that coincide with empirically derived graphs. Fifty electromechanical products from the design repository are used in this study. When comparing, the machine generated grammar rules with expert derived grammar rules, it can be seen that only 14% cannot be developed, 58% cannot be mined with the current setup and 28% were mined with the current set up. However, it is important to keep in mind a few considerations. Specifically, the technique does not replace the expert. Instead, the technique acts as more of an aid than a replacement. Also, while this technique has great potential in regards to computational design synthesis, it is limited to the products in the design repository and the current implementation of the aforementioned programs. Despite these minor considerations, this work proposes application of graph data mining to derive engineering grammars.

Automated Assignment of Physical Effects to Functions Using Ports Based on Bond Graphs

2011 ◽  
Author(s):  
Bergen Helms ◽  
Hansjo¨rg Schultheiß ◽  
Kristina Shea
Keyword(s):  
New Technologies ◽  
Selection Process ◽  
Innovation Process ◽  
Oriented Graph ◽  
Computational Design ◽  
Graph Grammar ◽  
Automated Assignment ◽  
Bond Graphs ◽  
Design Synthesis ◽  
Physical Effects

Innovation processes are highly susceptible to cyclic influences, such as evolving knowledge due to new technologies. In order to cope with these challenge, computational support is required. Paper-based design methods have vast amounts of knowledge at their disposal in the form of design catalogues. However, lacking a computational implementation, these knowledge sources provide no support for considering dynamic influences in the innovation process. The presented method is targeted at making the physical effects contained in design catalogues available for computational design synthesis approaches. For this purpose, this paper introduces the notion of abstraction ports that is used to represent the valid mapping between functional operators and physical effects. For the automated assignment of abstraction ports, a method has been developed that analyzes the equation structure of physical effects. This approach is derived from the modeling technique of bond graphs and is independent of any selection process proposed by design catalogues. Moreover, it allows for the formalization of evolving knowledge in new physical effects that are not yet contained in design catalogues. The assignment of abstraction ports has been successfully validated through the formalization of the physical effects of two design catalogues. Future work comprises the integration of quantitative characteristics of physical effects and the realization within the object-oriented graph grammar system booggie.

scholarly journals Systematic rule analysis of generative design grammars

2014 ◽  
Vol 28 (3) ◽  
pp. 227-238 ◽  
Author(s):  
Corinna Königseder ◽  
Kristina Shea
Keyword(s):  
Computational Design ◽  
Research Area ◽  
Synthesis Process ◽  
Analysis Method ◽  
Grammar Rule ◽  
Generative Design ◽  
Design Synthesis ◽  
Grammar Rules ◽  
Rule Analysis

AbstractThe use of generative design grammars for computational design synthesis has been shown to be successful in many application areas. The development of advanced search and optimization strategies to guide the computational synthesis process is an active research area with great improvements in the last decades. The development of the grammar rules, however, often resembles an art rather than a science. Poor grammars drive the need for problem specific and sophisticated search and optimization algorithms that guide the synthesis process toward valid and optimized designs in a reasonable amount of time. Instead of tuning search algorithms for inferior grammars, this research focuses on designing better grammars to not unnecessarily burden the search process. It presents a grammar rule analysis method to provide a more systematic development process for grammar rules. The goal of the grammar rule analysis method is to improve the quality of the rules and in turn have a major impact on the quality of the designs generated. Four different grammars for automated gearbox synthesis are used as a case study to validate the developed method and show its potential.

A Framework for Computational Design Synthesis Based on Graph-Grammars and Function-Behavior-Structure

2009 ◽  
Author(s):  
Bergen Helms ◽  
Kristina Shea ◽  
Frank Hoisl
Keyword(s):  
Graph Transformation ◽  
Computational Design ◽  
Synthesis Methods ◽  
Graph Grammars ◽  
Levels Of Abstraction ◽  
Product Model ◽  
Product Representation ◽  
Design Synthesis ◽  
Simulation Performance ◽  
Computational Design Synthesis

Computational design synthesis supports the knowledge-intensive process of developing new products. However, most approaches to date are often limited to a narrow domain and viewpoint of a synthesis task. The framework introduced in this paper aims to respond to the need for a method that integrates a richer product representation for computational synthesis within a framework that includes simulation, performance evaluation, and search. A computational and parameterized product model is presented that combines the Function-Behavior-Structure levels of abstraction. Graph-grammars are then used to create a formal definition of vocabulary and valid graph transformation rules. This approach offers the possibility to harness the large knowledge source of design catalogues in order to formulate vocabulary in a viewpoint-independent and thus, flexible way. In addition to manually entered and problem-specific rules, a class of generic rules is introduced that is instantiated computationally based on the defined vocabulary and has the advantage of being problem independent and re-usable. Finally, validation of the method is given through the synthesis of electric power-trains. This research goes beyond prior work in the field as it allows for synthesis and reasoning on different layers of abstraction, including function, behavior and structure, and introduces methods to alleviate the encapsulation of engineering knowledge for synthesis methods.

Computational Synthesis of Product Architectures Based on Object-Oriented Graph Grammars

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Bergen Helms ◽  
Kristina Shea
Keyword(s):  
Innovation Process ◽  
Object Oriented ◽  
Oriented Graph ◽  
Computational Design ◽  
Building Blocks ◽  
Graph Representation ◽  
Synthesis Process ◽  
Graph Grammars ◽  
Computational Synthesis ◽  
The Impact

Computational design synthesis aims to iteratively and automatically generate solution spaces of standard and novel design alternatives to support the innovation process. New approaches are required to generate alternative solutions at the function and behavior level as well as to ease the computational modeling of design knowledge. This paper introduces the approach of object-oriented graph grammars for the computational synthesis of product models based on a Function–Behavior–Structure (FBS) representation. The approach combines the advantages of a generic and systematic design method with a highly computable graph representation and object-oriented concepts. Through this combination, advances in terms of extendibility, efficiency, and flexible formalization of declarative and procedural engineering knowledge are achieved. Validation of the method is given through the synthesis of hybrid powertrains. The generation of hybrid powertrain solution spaces is shown, especially focusing on the impact of an evolving vocabulary, or building blocks, for synthesis. Future work includes integrating search methods in the synthesis process along with quantitative evaluation using simulation methods.

A Method for Visualizing the Relations Between Grammar Rules, Performance Objectives and Search Space Exploration in Grammar-Based Computational Design Synthesis

2015 ◽  
Author(s):  
Corinna Königseder ◽  
Kristina Shea
Keyword(s):  
Design Space Exploration ◽  
Design Space ◽  
Space Exploration ◽  
Computational Design ◽  
Search Space ◽  
Synthesis Process ◽  
Design Synthesis ◽  
Novel Approach ◽  
Grammar Rules ◽  
Computational Design Synthesis

Design grammars have been successfully applied in numerous engineering disciplines, e.g. in electrical engineering, architecture and mechanical engineering. A successful application of design grammars in Computational Design Synthesis (CDS) requires a) a meaningful representation of designs and the design task at hand, b) a careful formulation of grammar rules to synthesize new designs, c) problem specific design evaluations, and d) the selection of an appropriate algorithm to guide the synthesis process. Managing these different aspects of CDS requires not only a detailed understanding of each individual part, but also of the interdependencies between them. In this paper, a new method is presented to analyze the exploration of design spaces in CDS. The method analyzes the designs generated during the synthesis process and visualizes how the design space is explored with respect to a) design characteristics, and b) objectives. The selected algorithm as well as the grammar rules can be analyzed with this approach to support the human designer in successfully understanding and applying a CDS method. The case study demonstrates how the method is used to analyze the synthesis of bicycle frames. Two algorithms are compared for this task. Results demonstrate how the method increases the understanding of the different components in CDS. The presented research can be useful for both novices to CDS to help them gain a deeper understanding of the interplay between grammar rules and guidance of the synthesis process, as well as for experts aiming to further improve their CDS application by improving parameter settings of their search algorithms, or by further refining their design grammar. Additionally, the presented method constitutes a novel approach to interactively visualize design space exploration considering not only designs objectives, but also the characteristics and interdependencies of different designs.

scholarly journals A Computational Design Synthesis Method for the Generation of Rigid Origami Crease Patterns

2021 ◽  
pp. 1-57
Author(s):  
Luca Zimmermann ◽  
Kristina Shea ◽  
Tino Stankovic
Keyword(s):  
Rigid Body ◽  
Synthesis Method ◽  
Computational Design ◽  
Graph Grammar ◽  
Generative Design ◽  
Engineering Applications ◽  
Design Synthesis ◽  
Design Alternatives ◽  
Rigid Body Modes ◽  
Computational Design Synthesis

Abstract Today most origami crease patterns employed in technical applications are selected from a handful of well-known origami principles. Computational algorithms capable of generating novel crease patterns either target artistic origami, focus on quadrilateral creased paper, or do not incorporate direct knowledge for the purposeful design of crease patterns tailored to engineering applications. The lack of computational methods for the generative design of crease patterns for engineering applications arises from a multitude of geometric complexities intrinsic to origami, such as rigid foldability and rigid body modes, many of which have been addressed by recent work of the authors. Based on these findings, in this paper we introduce a Computational Design Synthesis method for the generative design of novel crease patterns to develop origami concepts for engineering applications. The proposed method first generates crease pattern graphs through a graph grammar that automatically builds the kinematic model of the underlying origami and introduces constraints for rigid foldability. Then, the method enumerates all design alternatives that arise from the assignment of different rigid body modes to the internal vertices. These design alternatives are then automatically optimized and checked for intersection to satisfy the given design task. The proposed method is generic and applied here to two design tasks that are a rigidly foldable gripper and a rigidly foldable robotic arm.

Layout synthesis of fluid channels using generative graph grammars

2014 ◽  
Vol 28 (3) ◽  
pp. 239-257 ◽  
Author(s):  
Amir Hooshmand ◽  
Matthew I. Campbell
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Large Scale ◽  
Three Dimensional ◽  
Graph Grammar ◽  
Future Research ◽  
Test Problems ◽  
Synthesis Methods ◽  
Graph Grammars ◽  
Design Synthesis

AbstractThis paper presents a new technique for shape and topology optimization of fluid channels using generative design synthesis methods. The proposed method uses the generative abilities of graph grammars with simulation and analysis power of conventional computational fluid dynamics methods. The graph grammar interpreter GraphSynth is used to carry out graph transformations, which define different topologies for a given multiple-inlet multiple-outlet problem. After evaluating and optimizing the generated graphs, they are first transformed into meaningful three-dimensional shapes. These solutions are then analyzed by a computational fluid dynamics solver for final evaluation of the possible solutions. The effectiveness of the proposed method is checked by solving a variety of available test problems and comparing them with those found in the literature. Furthermore, by solving very complex large-scale problems, the robustness and effectiveness of the method is tested. To extend the work, future research directions are presented.

A Framework for Computational Design Synthesis: Model and Applications

2005 ◽  
Vol 5 (3) ◽  
pp. 171-181 ◽  
Author(s):  
Jonathan Cagan ◽  
Matthew I. Campbell ◽  
Susan Finger ◽  
Tetsuo Tomiyama
Keyword(s):  
Computational Design ◽  
Active Area ◽  
Synthesis Process ◽  
Automated Synthesis ◽  
Design Problems ◽  
Design Synthesis ◽  
Industrial Practice ◽  
Research Challenges ◽  
Computational Design Synthesis ◽  
Open Issues

The field of computational design synthesis has been an active area of research for almost half a century. Research advances in this field have increased the sophistication and complexity of the designs that can be synthesized, and advances in the speed and power of computers have increased the efficiency with which those designs can be generated. Some of the results of this research have begun to be used in industrial practice, yet many open issues and research challenges remain. This paper provides a model of the automated synthesis process as a context to discuss research in the area. The varied works of the authors are discussed as representative of the breadth of methods and results that exist under the field of computational design synthesis. Furthermore, some guidelines are presented to help researchers and designers find approaches to solving their particular design problems using computational design synthesis.

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