bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effective Octree Generation of Parts for Virtual Prototyping
Authors: Chou T. C. , Liou F. W. , Reeves L. , McMillin B. , Suess Patricia 
Published: February 2021

Abstract
Virtual environment has become a future trend in design and development of new products, due to the current advances in simulation, computer graphics, robotics, and other related technologies. In order for the simulation engine to be efficient in performing tasks such as collision detection, the representation of the parts and components is very important. This paper presents an efficient algorithm to convert boundary representation (B-rep) to octree representation for efficient collision and interference detection. Traditionally, octree generation can be achieved through its original definition: build from the top level. This paper presents an innovative approach to build octree from the bottom level. This algorithm first transforms the boundary representation model into a triangle facet model and then a ray tracing technique is applied to scan all facets to create and record octants to a bit representation at the bottom level resolution. To save memory space, only the octants on the surface level are stored as black (solid) nodes. Finally a pointer representation of octree is built via the bit representation. The generation of a nine-level octree takes less then 60 seconds on a SunSparc 10. With this process, an octree can be quickly built for applications of collision and interference detection, such as robotic path planning, assembly planning, flight simulation, etc.
Building Block Design for Layered Shape Manufacturing
Authors: Binnard Mike , Cutkosky Mark R. 
Published: February 2021

Abstract
We are interested in designing complex mechatronic systems which closely integrate electronics, actuators, and sensors with mechanical structures. Rapid prototyping techniques open new design possibilities for these systems, such as the ability to fabricate pre-assembled mechanisms. This paper presents a design approach that should encourage exploration of these new possibilities and thereby facilitate robot design.
In the described approach, engineers build designs using a library of three dimensional primitives and aggregations of primitives. Associated with each primitive is enough manufacturing process information to enable immediate manufacturability analysis. An algorithm is presented which automatically combines the process information from multiple primitives. A prototype system using this algorithm has been implemented with AutoCAD and the ObjectARX programming interface.
An Incremental Part Manufacturing Cost Estimation Algorithm Using Petri Nets
Authors: Kiritsis Dimitris , Xirouchakis Paul 
Published: February 2021

Abstract
The problem under consideration is the cost estimation of part manufacturing while taking into account processing alternatives. In order to determine overall costs for feasible process plans we take into account, in our Petri net model, costs caused by machine, setup and tool changing in addition to the single operation cost. We introduce a new Petri net model that allows the application of incremental cost analysis algorithms. This is a CPP-net (Compact Process Planning net) which represents manufacturing knowledge in the form of precedence constraints and incorporates machining cost, machine, setup and tool information in each transition. We show that the CPP-net allows the calculation of the optimum process plan without the need to first develop all possible solutions. We apply the developed methods and calculate the optimum process plan to an industrial case study of a mechanical workpiece of moderate complexity.
Multi-Axis Roughing and Finishing of Ruled Surface Pockets for CAD/CAM Systems
Authors: Koc Bahattin , Lee Yuan-Shin 
Published: February 2021

Abstract
This paper presents a new methodology for 5-axis rough cutting of free-form ruled surface pockets. An Inclined Zig-zag method is proposed to rough cut the core region and an Ellipse-offset method is developed for semi-roughing and finishing the ruled surface pockets. The Ellipse-offset method is developed to calculate the non-constant offset curves for 5-axis tool path planning of rough cutting. Different from the traditional 2 1/2D machining method, the developed Ellipse-offset method allows the cutter to change its tool orientation and to get as close to the part surface as possible in roughing. The proposed method allows the manufacturing engineers to use 5-axis machining to rough cut the parts to near-finish shape for finishing. Computer implementation and illustrative examples are also presented in this paper.
A Geometric Theory for Formulation of Form, Profile and Orientation Tolerances: Problem Formulation
Authors: Gou J. B. , Chu Y. X. , Wu H. , Li Z. X. 
Published: February 2021

Abstract
This paper develops a geometric theory which unifies the formulation and evaluation of form (straightness, flatness, cylindricity and circularity), profile and orientation tolerances stipulated in ANSI Y14.5M standard. In the paper, based on an an important observation that a toleranced feature exhibits a symmetry subgroup G0 under the action of the Euclidean group, SE(3), we identify the configuration space of a toleranced (or a symmetric) feature with the homogeneous space SE(3)/G0 of the Euclidean group. Geometric properties of SE(3)/G0, especially its exponential coordinates carried over from that of SE(3), are analyzed. We show that all cases of form, profile and orientation tolerances can be formulated as a minimization or constrained minimization problem on the space SE(3)/G0, with G0 being the symmetry subgroup of the underlying feature. We transform the non-differentiable minimization problem into a differentiable minimization problem over an extended configuration space. Using geometric properties of SE(3)/G0, we derive a sequence of linear programming problems whose solutions can be used to approximate the minimum zone solutions.
A Single Function Agent Framework for Task Decomposition and Conflict Negotiation
Authors: Sreeram R. T. , Chawdhry P. K. 
Published: February 2021

Abstract
Researchers in agent-based concurrent engineering have identified a variety of techniques for product development with the use of multi-agents. Significant but less common are the techniques based on more task-specific single function agents. This paper proposes a single function agent framework for task-solving in a product development environment. This framework is based on Habermas’s theory of communicative action which is particularly suited for collaborative work. The inter-agent communication is based on Knowledge Query Manipulation Language (KQML). The task decomposition of the design process is based on the cluster identification algorithm. The conflicts which arise during the design process are resolved by using very specialized single function agents that detect conflicts based on violation of the design constraints. The case study on the design of a mechanical shaft demonstrates the appropriateness of the proposed framework.
Developing ‘Text Learning Capture’ to Examine How Students Learn From Texts and How Texts Learn From Students
Authors: Sheppard Sheri , Jones Kim , Jeremijenko Natalie 
Published: February 2021

Abstract
This paper describes an innovative assessment method that provides formative feedback on the effectiveness of an engineering textbook. We describe the development of the Text Learning Capture Method and the prior art that it is drawn from. We then go on to interpret and analyze the protocols captured with the method and describe the preliminary results generated with its application. Concrete examples of how the feedback enables us to identify the text’s readability, comprehensibility, and usability are given. From the analysis a list of questions was generated about how students learn from engineering textbooks.
The textbook assessment work presented here was motivated by a desire on the part of the author of the textbook (hereafter the text-author in contrast to the authors of this paper) to understand more fully the role of this textbook in supporting student learning. We began with questions such as: “Do students relate to the real-world examples given?”; “How do students work through the equations?”; “How are figures utilized?”; “Are students excited by a textbook that uses a familiar multi-faceted artifact to demonstrate engineering principles?”. In our attempts to carefully answer these questions we generated questions such as: “Can learning from a text book be thought of as passive?”; “What constitutes effective learning from texts?”; “What are best reading practices?”; and “How much control does an author have over this?”.
Identification of Limiting Factors for Improving Design Modularity
Authors: Coulter Stewart L. , McIntosh Mark W. , Bras Bert , Rosen David W. 
Published: February 2021

Abstract
In previous work, the idea of designing for the life cycle (DFLC) was investigated through the improvement of product architectures with an emphasis on increasing modularity. In this paper, that work is extended by developing a method for suggesting changes to the product to improve the correspondence between modules from different life-cycle viewpoints. Based on an analogy to the determination of critical paths in network analysis, the identification of limiting factors in a candidate design is intended to assist the designer in recognizing design changes that have the greatest impact on improving recyclability. The purpose of this paper is to illustrate how the identification of limiting factors can be used to improve product recyclability during configuration design. A general method for identifying and prioritizing the limiting factors is presented and applied in the context of improving recyclability. This method is shown to be capable of efficiently determining effective design changes to improve product modularity and recyclability. It is argued that the concept of limiting factors and the developed method are applicable to many different configuration design issues and not limited to recycling or even other DFLC issues. A validation of the limiting factor identification method is presented using a Genetic Algorithm and an exhaustive search.
A Design Process Modeling Approach Incorporating Nonlinear Elements
Authors: Andersson Johan , Pohl Jochen , Eppinger Steven D. 
Published: February 2021

Abstract
This paper extends the literature of engineering design process modeling. We focus on the modeling of design iterations using a task-based description of a development project. We present a method to compute process performance and to relate this outcome to critical activities within the process.
Design tasks are modeled as discrete-event activities with design information flowing between them. With every design task, we associate process characteristics such as the completion time and cost per time unit for the task. These characteristics can change with the advance of the design process. The method is especially suited for comparison of different design processes on the basis of overall process costs and lead time.
In order to illustrate the method a simple design process was modeled as an example. Based on this model the process lead time distribution and the process costs were simulated.
Design Information Retrieval: Improving Access to the Informal Side of Design
Authors: Wood William H. , Yang Maria C. , Cutkosky Mark R. , Agogino Alice M. 
Published: February 2021

Abstract
Capturing and reusing design experience holds great potential for improving designer effectiveness The first step toward leveraging lessons from the past for design decision making is gaining access to them Because decisions early in the design process largely determine its ultimate success, it is important to embrace the informal, unstructured information that is prevalent during conceptual design Information retrieval is proposed as the basis for access to this informal design information By creating hierarchical thesauri of life cycle design issues, design process terms, and component and system functional decompositions, we hope to establish an intermediate language in which design context can be captured Experiments in design information retrieval exploiting design context for determining document similarity within design case studies and design notebooks demonstrate the value of this approach.
A Workcell Based Robot Design Program
Authors: Derby Stephen 
Published: February 2021

Abstract
This paper discusses a computer graphics program that helps to design a robot based on an existing workcell that would be difficult or costly to modify. Standard robot bases, as well as tracked robots, are located to minimize the error of the desired taught robot gripper positions. Error levels are established based on the angle of the misalignment and the length of the required loading or unloading motion. Program implementation is detailed.
Incorporation of Vibration Control in Determination of Structural Parameters of Gear Systems
Authors: Wang Y. , Zhang W. J. , Kalker-Kalkman C. M. , Li Q. 
Published: February 2021

Abstract
A new design strategy of gear system is proposed in this paper. Traditionally, development of gear systems undergoes as such. First gear structural parameters are determined. Then control of dynamic behaviours such as control of vibration is dealt with, where gear structural parameters cannot be changed any more. The new strategy suggests that during the design process of determining gear structure parameters, vibration control is taken into account. In order to see the effects of such a design strategy, an optimal design model is developed which contains two conflicting objectives, system vibration and system volume. The design variables include both discrete ones and continuous ones. Genetic algorithm, together with Pareto sets, is employed to solve this complex optimal problem. Through the simulation studies on selected cases, improvement on the system vibration control is shown with this new design strategy.
Automated Motion Program Formulation for Cam Mechanism Design
Authors: Shooter Steven B. 
Published: February 2021

Abstract
The required motion for a cam mechanism is often an under-defined problem. Usually only part of the motion cycle is specified, giving the designer freedom to generate the remaining motion to best suit the dynamic constraints. Often, it is the motion program that has the greatest effect on the dynamic performance of the cam mechanism. Formulating the motion program often involves iteratively specifying motion types, selecting follower types and selecting cam characteristics. Many software programs have been developed to synthesize the cam profile when the desired motion program and the cam mechanism characteristics have been supplied, and the cam profile synthesis techniques have been well established. However, such programs do not assist the designer in formulating the motion program. This paper presents a software system which assists the designer through the process of formulating the motion program. The program provides information to aid decision making in this under-defined problem. It also includes an analytical technique for automating the curve-matching required to formulate the motion program. The automation of these procedures allows the designer to readily explore alternatives and produce a superior design.
Computation of Pressure Loads in the Three-Lobe Supercharger
Authors: Mimmi Giovanni C. , Pennacchi Paolo E. 
Published: February 2021

Abstract
The compression mechanism in this type of blower is produced by the action of two three-lobe rotors. In this paper the functioning of this kind of blower is analyzed in detail for both the helical and spur rotor types. The analysis allows us to point out specific problems regarding trapped volumes and to design special devices to avoid these problems.
The complete dynamics of the loads is determined on this basis, and the performances achieved by helical and spur rotors are compared.
The Torque Responses in Spur Gearing
Authors: Lin Ah-Der , Kuang Jao-Hwa 
Published: February 2021

Abstract
In this study, the frequency spectra of a meshing spur gear pair are derived. A two-step mesh stiffness model is assumed to account for the time varying stiffness during the teeth engagement. The analytic load of this simplified gear pair system is used to derive the corresponding Fourier expansion series of the transmitted torque in close form solutions. Numerical results have shown that the frequency spectra of the transmitted torque are dominated by the mesh stiffness alternation and the contact ratio of a gear pair. Furthermore, the amplitude modulation introduced by a harmonic input torque has also been investigated.
A New Inertia-Based Linear Stepper Motor for Micro-Surgical Procedures
Authors: Rizq Raed N. , Peichel David J. , Wulfman David R. , Erdman Arthur G. , Polla Dennis L. 
Published: February 2021

Abstract
A new hand held surgical device intended to aid physicians in microsurgery is reported. This device provides a means for delivering small implants through the use of a precision motion linear stepper motor fabricated from silicon and piezoelectric components. The stepper motor described here utilizes the inertial properties of a moving mass as part of the actuation process. Micro Electromechanical Systems-based (MEMS) technology is used in building the device. Test instruments have delivered over fifty implants with consistent performance. Typically the test instruments have attained 1.2 mm/s advancement speeds against 3 Newton resistance loads, a maximum output force of 4.6 Newtons, and maximum total displacement of 38 mm.
Optimal Design Using Chaotic Descent Method
Authors: Jovanovic Vojin , Kazerounian Kazem 
Published: February 2021

Abstract
This paper presents a novel method for locating global minima in design optimization problems. The method is applicable to any general nonlinear function. It is based on utilizing sensitive fractal areas to locate all of the solutions along one direction in variable space. The search begins from an arbitrary chosen point in the space and descends towards a better design along a randomly chosen direction. Descent depends on finding points that belong to Julia set from which all of the solutions along that direction can be located. The process is repeated until optimal design is obtained. To examine the behavior of the algorithm appropriate examples were selected and results discussed.
Numerical Solution for Manipulator Forward Dynamics BVPs
Authors: Pasic Hajrudin , Williams Robert L. , Hui Chunwu 
Published: February 2021

Abstract
A new algorithm is presented for iterative solution of systems of nonlinear ordinary differential equations (ODEs) with any order for multibody dynamics and control problems. The collocation technique (based on the explicit fixed-point iteration scheme) may be used for solving both initial value problems (IVPs) and boundary value problems (BVPs). The BVP is solved by first transforming it into the IVP. If the Lipschitz constant is large and the algorithm diverges in a single (‘long’) domain, the domain is partitioned into a number of subdomains and the local solutions of the corresponding BVPs are matched either locally (in parallel) or globally. The technique is general and may be applied to general systems of ODEs in any field. As an illustration, the forward dynamics problem of a manipulator is solved as an IVP and then as a BVP.
Geometric Criteria for Gouge-Free Three-Axis Milling of Sculptured Surfaces
Authors: Pottmann Helmut , Wallner Johannes , Glaeser Georg , Ravani Bahram 
Published: February 2021

Abstract
The paper presents a geometric investigation of collision-free 3-axis milling of surfaces. We consider surfaces with a global shape condition: they shall be interpretable as graphs of bivariate functions or shall be star-shaped with respect to a point. If those surfaces satisfy a local millability criterion involving curvature information, it is proved that this implies globally gouge-free milling. The proofs are based on general offset surfaces. The results can be applied to tool-motion planning and the computation of optimal cutter shapes.
An Assessment of Geometric Methods in Trajectory Synthesis for Shape Creating Operations
Authors: Sarma Radha 
Published: February 2021

Abstract
This paper presents an assessment of the steps involved in trajectory synthesis (e.g., trajectory layout, trajectory generation, trajectory spacing, trajectory postprocessing, and trajectory physics) for shape creating manufacturing operations, e.g., rapid prototyping, milling, electrical discharge machining. The rationale for this paper is that the trajectory plays an important role in determining the productivity as explained below.
Shape creating manufacturing operations are those that make use of a “tool” which operates on a “workpiece” to create the desired shape. The tool operates on the workpiece as dictated by the trajectory of the tool, resulting in the manufactured shape. Often, the geometric and functional properties of the end product are dependent on the trajectory of the tool. Moreover, the trajectory dictates the accuracy of the end product and the time taken to manufacture the product. Recognizing the important contribution of the trajectory in shape creating operations, this paper focuses on trajectory synthesis.
Classification and Interpretation of the Singularities of Redundant Mechanisms
Authors: Zlatanov Dimiter S. , Fenton Robert G. , Benhabib Beno 
Published: February 2021

Abstract
This paper introduces a unified approach to the singularity analysis of mechanisms with arbitrary kinematic chains and any number of inputs or outputs. The presented framework for the interpretation and classification of singularities is obtained by generalizing previous results (Zlatanov et al, 1995) valid only for non-redundant mechanisms. A velocity-space model is used to describe the instantaneous kinematics and interpret mechanism singularity. The definition of six singularity types and the study of their interdependence in the case of redundant mechanisms yield a comprehensive singularity classification.
Polynomial Solutions to the Displacement Analysis of 10-Link 1-DOF Mechanisms
Authors: Dhingra A. K. , Almadi A. N. , Kohli D. 
Published: February 2021

Abstract
This paper presents closed-form polynomial solutions to the displacement analysis problem of planar 10-link mechanisms with 1 degree-of-freedom (DOF). Using the successive elimination procedure presented herein, the input-output (I/O) polynomials as well as the number of assembly configurations for five mechanisms resulting from two 10-link kinematic chains are presented. It is shown that the displacement analysis problems for all five mechanisms can be reduced to a univariate polynomial devoid of any extraneous roots. This univariate polynomial corresponds to the I/O polynomial of the mechanism. In addition, one of the examples also illustrates how trigonometric manipulations in conjunction with tangent half-angle substitutions can lead to non-trivial extraneous roots in the solution process. Theoretical conditions for identifying and eliminating these extraneous roots are also presented.
A New Efficient Algorithm of Finding Optimum Code Based on Incident Degree
Authors: Deng Zhao-Hui , Luo Yu-Feng , Xu Zheng 
Published: February 2021

Abstract
A new efficient and robust algorithm based on incident degree, called recurrently dividing of matrix (RDM), has been developed for finding optimum code in detecting isomorphism among planar or spatial kinematic chains which can be represented by weighted graphs, adjacent matrices or matrix codes. The developed algorithm uses the recurring methods to order and divide adjacent matrix into various areas with different connection property so that the optimum code is found. Salient feature of this algorithm is removing computational inefficiency and remaining unique value of code approach in generating the codes, and able to detect symmetry in kinematic chains in the light of it.