The Effects of Language and Pruning on Function Structure Interpretability

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Benjamin W. Caldwell ◽  
Jonathan E. Thomas ◽  
Chiradeep Sen ◽  
Gregory M. Mocko ◽  
Joshua D. Summers
Keyword(s):  
User Study ◽  
Function Structure ◽  
Design Recommendations ◽  
Functional Basis ◽  
Level Of Abstraction ◽  
Functional Models ◽  
Design Activities ◽  
Free Language ◽  
Function Structures

In this research, the interpretability of function structures is evaluated through a user study in which participants are given function structures and asked to identify the product that is modeled. Two abstraction factors are controlled in the experiment: the type of functions and the specificity of the terms, thus resulting in functional models are four level of abstraction. The user study shows that free language significantly improves the accuracy and speed of human interpretability over the functional basis vocabulary. Further, pruned function structures significantly improve the speed of interpretability over reverse-engineered function structures without a loss of accuracy. It is concluded that the levels of each factor are useful for different activities and stages of design. Recommendations are made for the appropriate combinations of factor levels for various design activities.

scholarly journals Conceptual Design of Electromechanical Actuation Systems for Large-Sized Directional Control Valves

Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 133
Author(s):  
Tobias Vonderbank ◽  
Katharina Schmitz
Keyword(s):  
Conceptual Design ◽  
Design Process ◽  
Operating Conditions ◽  
Function Structure ◽  
Advantages And Disadvantages ◽  
Conceptual Designs ◽  
Actuation Systems ◽  
Electromechanical Actuation ◽  
Function Structures ◽  
Valve Actuation

Increasing performance in modern hydraulics is achieved by a close investigation of possible enhancements of its components. Prior research has pointed out that electromechanical actuators can form suitable alternatives to hydraulically piloted control systems. Since the requirements at these actuation systems depend on the operating conditions of the system, each actuator can be optimized to the respective hydraulic system. Considering that many different conceptual designs are suitable, the phase of conceptual design plays a decisive role during the design process. Therefore, this paper focuses on the process of developing new conceptual designs for electromechanical valve actuation systems using the method of function structures. Aiming to identify special design features, which need to be considered during the design process of electromechanical actuation systems, an exemplary actuator was designed based on the derived function structure. To highlight the potential of function structures for the development of new electromechanical valve actuation systems, two principal concepts, which allow the reduction of the necessary forces, have been developed by extending the function structure. These concepts have been experimentally investigated to identify their advantages and disadvantages.

A Statistical Approach to Ranking Similarities of Three Function Structure Groups Using Directed Graphs

2018 ◽  
Author(s):  
Briana M. Lucero ◽  
Matthew J. Adams
Keyword(s):  
Statistical Approach ◽  
Directed Graphs ◽  
Proof Of Concept ◽  
Function Structure ◽  
Fundamental Properties ◽  
Design Engineers ◽  
Functional Representation ◽  
Structure Databases ◽  
Further Development ◽  
Function Structures

Prior efforts in the study of engineering design employed various approaches to decompose product design. Design engineers use functional representation, and more precisely function structures, to define a product’s functionality. However, significant barriers remain to objectively quantifying the similarity between two function structures, even for the same product when developed by multiple designers. For function-structure databases this means that function-structures are implicitly categorized leaving the possibility of incorrect categorization and reducing efficacy of returned analogous correlations. Improvements to efficacy in database organization and queries are possible by objectively quantifying the similarity between function structures. The proposed method exploits fundamental properties of function-structures and design taxonomies. We convert function-structures into directed graphs (digraphs) and equivalent adjacency matrices. The conversion maintains the directed (function → flow → function) progression inherent to function-structures and enables the transformation of the function-structure into a standardized graph. For design taxonomies (e.g. D-APPS), graph nodes represent flows in a consistent (but arbitrary) ordering. By exploiting the directional properties of function-structures and defining the flows as the graphical nodes, the objective and standardized comparison of two function-structures becomes feasible. We statistically quantify the association between digraphs using the Pearson Product Moment Correlation (PPMC) for both within-group and between-group comparisons. The method was tested on three product types (ball thrower, food processor, and an ice cream maker) with function-structures defined by various designers. The method suggested herein is provided as a proof-of-concept with suggested verification and validation approaches for further development.

Identifying Product Portfolio Architecture Modularity Using Function and Variety Heuristics

1999 ◽  
Author(s):  
Erik J. Zamirowski ◽  
Kevin N. Otto
Keyword(s):  
Product Variety ◽  
Product Portfolio ◽  
Functional Constraints ◽  
Function Structure ◽  
Customer Needs ◽  
Product Use ◽  
Individual Product ◽  
Product Function ◽  
Target Values ◽  
Function Structures

Abstract This paper proposes a method for identifying product portfolio architecture alternatives based upon customer needs and product function. Customer needs and uses are interpreted according to the variation in performance target values across the market and within the set of individual customer uses. Product uses are represented by function structures consisting of the functions necessary for achieving the use. These individual product use function structures are combined into a monolithic function structure to represent the entire product portfolio. This monolith is then partitioned according to function and product variety heuristics into function clusters that anticipate product modules. This candidate modularity can then be used to deliver product variety across the product portfolio given functional constraints. A portfolio of xerographic products is used as the working example.

Applying Functional Modeling as a Unifying Basis for Design for Six Sigma Execution

2004 ◽  
Author(s):  
Ryan S. Hutcheson ◽  
Joseph A. Donndelinger ◽  
Daniel A. McAdams ◽  
Robert B. Stone
Keyword(s):  
Six Sigma ◽  
General Motors ◽  
Functional Modeling ◽  
University Of Missouri ◽  
Functional Basis ◽  
Design For Six Sigma ◽  
Parking Brake ◽  
Functional Models ◽  
The University ◽  
Current Engineering

This paper explores the applicability of the most recently developed methods in functional modeling to Design for Six Sigma transfer function development and requirements flowdown. An example created during a collaborative research project between the General Motors R&D Center and the University of Missouri – Rolla is used to demonstrate the benefits of using standardized functional modeling during conceptual design. The proposed standard for creating the functional models is the Functional Basis. The Functional Basis is a list of function and flow terms that can be used to describe electro-mechanical systems. The example presented in this paper is based on the parking brake system of a passenger car. Module heuristics, function-based rules for partitioning systems, were used to define the sub-systems during the requirements flowdown example. The functional modeling techniques used in this example provide a standard method of capturing current engineering design knowledge while allowing additional knowledge to be discovered.

Development of a Functional Basis for Design

1999 ◽  
Author(s):  
Robert B. Stone ◽  
Kristin L. Wood
Keyword(s):  
Classification Scheme ◽  
Mechanical Design ◽  
Functional Model ◽  
Coding System ◽  
Structure Generation ◽  
Functional Basis ◽  
Product Function ◽  
Functional Models ◽  
Functional Representations ◽  
Architecture Development

Abstract Functional models represent a form independent blueprint of a product. As with any blueprint or schematic, a consistent language or coding system is required to ensure others can read it. This paper introduces such a design language, called a functional basis, where product function is characterized in a verb-object (function-flow) format. The set of functions and flows is intended to comprehensively describe the mechanical design space. Clear definitions are provided for each function and flow. The functional basis is compared to previous functional representations and is shown to subsume these attempts as well as offer a more consistent classification scheme. An example is provided for using the functional basis to form a functional model. Applications to the areas of product architecture development, function structure generation, and design information archival and transmittal are discussed.

scholarly journals Introduction to quantitative engineering design methods via controls engineering

2017 ◽  
Vol 31 (4) ◽  
pp. 458-475 ◽  
Author(s):  
Briana M. Lucero ◽  
Matthew J. Adams ◽  
Cameron J. Turner
Keyword(s):  
Engineering Design ◽  
Design Process ◽  
Performance Metrics ◽  
Mathematical Function ◽  
Functional Modeling ◽  
Bond Graphs ◽  
Functional Basis ◽  
Controls Engineering ◽  
Controls Systems ◽  
Function Structures

AbstractFunctional modeling is an effective method of depicting products in the design process. Using this approach, product architecture, concept generation, and physical modeling all contribute to the design process to generate a result full of quality and functionality. The functional basis approach provides taxonomy of uniform vocabulary to produce function structures with consistent functions (verbs) and flows (nouns). Material and energy flows dominate function structures in the mechanical engineering domain with only a small percentage including signal flows. Research suggests that the signal flow gap is due to the requirement of “carrier” flows of either material or energy to transport the signals between functions. This research suggests that incorporating controls engineering methodologies may increase the number of signal flows in function structures. We show correlations between the functional modeling and controls engineering in four facets: schematic similarities, performance matching through flows, mathematical function creation using bond graphs, and isomorphic matching of the aforementioned characteristics allows for analogical solutions. Controls systems use block diagrams to represent the sequential steps of the system. These block diagrams parallel the function structures of engineering design. Performance metrics between the two domains can be complimentary when decomposed down to nondimensional engineering units. Mathematical functions of the actions in controls systems can resemble the functional basis functions with bond graphs by identifying characteristic behavior of the functions on the flows. Isomorphic matching, using the schematic diagrams, produces analogies based upon similar functionality and target performance metrics. These four similarities bridge the mechanical and electrical domains via the controls domain. We provide concepts and contextualization for the methodology using domain-agnostic examples. We conclude with suggestion of pathways forward for this preliminary research.

User Study: Influence of Number of Design Errors on Ability to Predict Performance With and Without Controls

2013 ◽  
Author(s):  
Somaiah Thimmaiah ◽  
Keith Phelan ◽  
Joshua D. Summers
Keyword(s):  
Engineering Students ◽  
User Study ◽  
Failure Modes ◽  
P Value ◽  
First Year ◽  
Psychology Class ◽  
Design Activities ◽  
Undergraduate Psychology ◽  
Domain Familiarity ◽  
The Impact

Design reviews are typically used for three types of design activities: 1) identifying errors, 2) assessing the impact of the errors, and 3) suggesting solutions for the errors. This experimental study focuses on understanding the second issue as it relates to the number of errors considered, the existence of controls, and the level of domain familiarity of the assessor. A set of design failures and associated controls developed for a completed industry sponsored project is used as the experimental design problem. Non-domain individuals (students from an undergraduate psychology class), domain generalists (first year engineering students), and domain-specialists (graduate mechanical engineering students) are provided a set of failure modes and asked to estimate the likelihood that the system would still successfully achieve the stated objectives. Primary results from the study include the following: the confidence level for all domain population decreased significantly as the number of design errors increased (largest p-value = 0.0793) and this decrease in confidence is more significant as the design errors increase. The impact on confidence is less when solutions (controls) are provided to prevent the errors (largest p-value = 0.0334), the confidence decreased faster for domain general engineers as compared to domain specialists (p = <0.0001). The domain specialists showed higher confidence in making decisions than domain generals and non-domain generalists as the design errors increase.

An Ontology of Classification Criteria for Functional Taxonomies

2011 ◽  
Author(s):  
Yoshinobu Kitamura ◽  
Sho Segawa ◽  
Munehiko Sasajima ◽  
Riichiro Mizoguchi
Keyword(s):  
Classification Criteria ◽  
Search System ◽  
Functional Basis ◽  
Functional Models ◽  
Document Search ◽  
Classification Structure

In order to facilitate sharing of functional models, some functional taxonomies each of which provides a set of verbs for representing generic functions (called functional terms here) have been developed. Their examples include some sets of generally valid functions in the book written by Pahl and Beitz, Functional Basis (FB) developed by Hirtz et al. and FOCUS/Tx developed by the authors of this paper. The issue addressed in this paper is the implicitness of the criteria of classification of functional terms in those taxonomies and thus unclearness of their definitions. This paper proposes an ontology of logical criteria for classification of functional terms (called FOCUS/View). Using the classes defined in FOCUS/View, the classification criteria of a functional taxonomy can be explicitly represented. These classes have been conceptualized based on deep investigation on FB and FOCUS/Tx. The benefits of the proposed FOCUS/View ontology include: (1) users of a taxonomy can easily understand differences of similar terms and select an appropriate term out of them, (2) a developer of a taxonomy can check its logical classification structure and then improve its logical clearness, and (3) we can compare different taxonomies and establish more reliable mappings between their terms for interoperability of functional models. In this paper, as a demonstration of the benefit (1), the classification criteria of FB, FOCUS/Tx, Krumhauer’s and Roth’s generally valid functions are explicitly presented using FOCUS/View. As a demonstration of the benefit (2), some logically problematic classification structures of FB and the Krumhauer’s functions are discussed and modified for the logical clearness. For the benefit (3), this paper demonstrates the mappings between FB and FOCUS/Tx and a semantic interoperable document search system based on these mappings.

Impact of Level of Detail and Information Content on Accuracy of Function Structure-Based Market Price Prediction Models

2016 ◽  
Author(s):  
Amaninder Singh Gill ◽  
Joshua D. Summers ◽  
Cameron J. Turner
Keyword(s):  
Prediction Models ◽  
Market Price ◽  
Level Of Detail ◽  
Research Approach ◽  
Function Structure ◽  
Amount Of Information ◽  
Market Values ◽  
Grammar Rules ◽  
Model Set ◽  
Function Structures

This paper explores the amount of information stored in the representational components of a function structure: vocabulary, grammar, and topology. This is done by classifying the previously developed functional composition rules into vocabulary, grammatical, and topological classes and applying them to function structures available in an external design repository. The pruned function structures of electromechanical devices are then evaluated for how accurately market values can be predicted using graph complexity connectivity method. The accuracy is inversely with amount of information and level of detail. Applying the topological rule does not significantly impact the predictive power of the models, while applying the vocabulary rules and the grammar rules reduce the accuracy of the predictions. Finally, the least predictive model set is that which had all rules applied. In this manner, the value of a representation to predict or answer questions is quantified through this research approach.

Development of a Functional Basis for Design

1999 ◽  
Vol 122 (4) ◽  
pp. 359-370 ◽  
Author(s):  
Robert B. Stone ◽  
Kristin L. Wood
Keyword(s):  
Design Space ◽  
Classification Scheme ◽  
Mechanical Design ◽  
Coding System ◽  
Structure Generation ◽  
Functional Basis ◽  
Product Function ◽  
Functional Models ◽  
Functional Representations ◽  
Architecture Development

Functional models represent a form independent blueprint of a product. As with any blueprint or schematic, a consistent language or coding system is required to ensure others can read it. This paper introduces such a design language, called a functional basis, where product function is characterized in a verb-object (function-flow) format. The set of functions and flows is intended to comprehensively describe the mechanical design space. Clear definitions are provided for each function and flow. The functional basis is compared to previous functional representations and is shown to subsume these attempts as well as offer a more consistent classification scheme. Applications to the areas of product architecture development, function structure generation, and design information archival and transmittal are discussed. [S1050-0472(00)00704-2]

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