bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Parametric Approach to the Optimization-Based Design of Compliant Mechanisms
Authors: Parkinson Matthew B. , Howell Larry L. , Cox Jordan J. 
Published: February 2021

Abstract
Several optimization-based strategies have been proposed for compliant mechanism design that do not rely on the experience or intuition of the designer. This paper demonstrates an optimization-based method wherein compliant mechanisms are modeled parametrically within an optimization and a finite element analysis package. Topological optimization is performed to minimize an objective function representing the fitness of the design. This methodology exploits the nonlinear nature of compliant mechanisms and augments optimization-based methods previously proposed.
Using this method, constant-force mechanisms optimized for a displacement from 4% to 25% of the mechanism’s total length were predicted to remain within 3.58% of constant force. Results from the testing of fabricated mechanisms are: for 4–25% displacement, within 7.5% constant force; for 18–65% displacement, within 2.3%. Path generation mechanisms were designed with similarly encouraging results.
Applying Virtual Reality Techniques to Sensitivity-Based Structural Shape Design
Authors: Yeh Tsung-Pin , Vance Judy M. 
Published: February 2021

Abstract
Virtual reality (VR) provides a design space consisting of three-dimensional computer images where participants can interact with these images using natural human motions in real time. In the field of engineering design, prototyping and design verification have provided the initial application areas for VR. The research presented in this paper takes the scenario one step further by incorporating free-form deformation techniques and sensitivity analysis into the virtual world such that the designer can easily implement analysis-based shape design of a structural system where stress considerations are important. NURBS-based free-form deformation (NFFD) methods and direct manipulation techniques are used as the interface between the VR interaction and the finite element model. Sensitivity analysis is used to allow the designer to change the design model and immediately view the effects without performing a re-analysis. An engine connecting rod is analyzed to demonstrate how virtual reality techniques can be applied to structural shape design.
Vibration of Nearly Perfect Spring Equilibrators
Authors: Soper R. Randall , Mook Dean T. , Reinholtz Charles F. 
Published: February 2021

Abstract
Perfect spring equilibrators balance an eccentric rotating weight over a wide range of motion. The mechanism relies on a spring of zero free length. One practical implementation uses a spring and cable of finite free length wrapped over a pulley located at the grounded spring attachment point of the ideal mechanism. The pulley of finite radius introduces some error in the balancing moment.
In this paper the kinematics of a practically implemented perfect spring equilibrator are developed. Two kinematic cases are shown to exist. In one case, the kinematics are periodic in the weight arm rotation. In the other case, the geometry causes the spring cable to wrap or unwrap resulting in non-periodic kinematics. Phase portraits are used to illustrate the nonlinear dynamics of the system. The effect of various parameters are examined.
Trust Region Augmented Lagrangian Methods for Sequential Response Surface Approximation and Optimization
Authors: Rodríguez José F. , Renaud John E. , Watson Layne T. 
Published: February 2021

Abstract
A common engineering practice is the use of approximation models in place of expensive computer simulations to drive a multidisciplinary design process based on nonlinear programming techniques. The use of approximation strategies is designed to reduce the number of detailed, costly computer simulations required during optimization while maintaining the pertinent features of the design problem. To date the primary focus of most approximate optimization strategies is that application of the method should lead to improved designs. This is a laudable attribute and certainly relevant for practicing designers. However to date few researchers have focused on the development of approximate optimization strategies that are assured of converging to a solution of the original problem. Recent works based on trust region model management strategies have shown promise in managing convergence in unconstrained approximate minimization. In this research we extend these well established notions from the literature on trust-region methods to manage the convergence of the more general approximate optimization problem where equality, inequality and variable bound constraints are present. The primary concern addressed in this study is how to manage the interaction between the optimization and the fidelity of the approximation models to ensure that the process converges to a solution of the original constrained design problem. Using a trust-region model management strategy, coupled with an augmented Lagrangian approach for constrained approximate optimization, one can show that the optimization process converges to a solution of the original problem. In this research an approximate optimization strategy is developed in which a cumulative response surface approximation of the augmented Lagrangian is sequentially optimized subject to a trust region constraint. Results for several test problems are presented in which convergence to a Karush-Kuhn-Tucker (KKT) point is observed.
Robot Manipulator Trajectory Synthesis for Minimal Vibrational Excitation
Authors: Kim W. , Rastegar J. 
Published: February 2021

Abstract
As a robot manipulator is forced to track a given trajectory, the required actuating torques (forces) may excite the natural modes of vibration of the system. Due to their nonlinear dynamics, internally and externally induced high harmonic excitation torques are generally generated even though such harmonics have been eliminated from the synthesized trajectories and filtered from the drive inputs. It is therefore desirable to synthesize trajectories such that the actuating torques required to realize them do not contain higher harmonic components with significant amplitudes. In this paper, a systematic method is presented for synthesizing such trajectories. With such trajectories, a robot manipulator can operate at higher speeds and achieve higher tracking accuracy with suppressed residual vibration. It is shown that in general and for a given starting point, such trajectories can only be synthesized to a portion of the operating space of the manipulator. The method is developed based on the Trajectory Pattern Method (TPM). The application of the method to optimal trajectory synthesis for a plane 2R manipulator is presented.
Trajectory Synthesis and Redundancy Resolution for High Speed Point to Point Motions of Redundant Robot Manipulators
Authors: Kim W. , Rastegar J. 
Published: February 2021

Abstract
Trajectory synthesis for robot manipulators with redundant kinematic degrees-of-freedom has been studied by numerous investigators. Redundant manipulators are of interest since the redundant degrees-of-freedom can be used to improve the local and global kinematic and dynamic performance of a system. As a robot manipulator is forced to track a given trajectory, the required actuating torques (forces) may excite the natural modes of vibration of the system. Noting that manipulators with revolute joints have nonlinear dynamics, high harmonic excitation torques are generally generated even though such harmonics have been eliminated from the synthesized trajectories and filtered from the drive inputs. In this paper, a redundancy resolution method is developed based on the Trajectory Pattern Method (TPM) to synthesize trajectories such that the actuating torques required to realize them do not contain higher harmonic components with significant amplitudes. With such trajectories, a robot manipulator can operate at higher speeds and achieve higher tracking accuracy with suppressed residual vibration. As an example, optimal trajectories are synthesized for point to point motions of a plane 3R manipulator.
Designing Dynamically Compensated and Robust Cam Profiles With Bernstein-Bézier Harmonic Curves
Authors: Srinivasan Lakshmi N. , Ge Q. Jeffrey 
Published: February 2021

Abstract
This paper deals with the problem of designing dynamically compensated cam profiles to minimize residual vibrations in high-speed cam-follower systems. The traditional Polydyne method is modified and extended to achieve significant improvement in residual vibration characteristics. First, cam displacement curves are represented by Bernstein-Bézier harmonic curves as opposed to polynomial curves. These recently developed harmonic curves are low in harmonic content and therefore the resulting cam profiles are less prone to induce resonant vibrations in the follower system. Second, the design procedure is expanded such that the residual vibrations of the resulting cam-follower system is not only extinguished at the design speed but also made insensitive to speed variations. Numerical examples are given in the end.
Collaborative Optimization of Systems Involving Discrete Design at the Discipline Level
Authors: Balling Richard J. , Gale Dallas L. 
Published: February 2021

Abstract
The multidisciplinary design optimization technique known as collaborative optimization is extended to multidisciplinary systems in which disciplines employ discrete search strategies. A particular test case is examined in which discrete disciplinary design is accomplished via exhaustive search. Even though non-gradient-based search strategies are used for disciplinary design, a procedure is developed in which gradient-based nonlinear programming algorithms can be used at the system level to coordinate the work of the disciplines.
Dynamic Force Analysis of the Carpal Wrist
Authors: Canfield Stephen L. , Soper R. Randall , Reinholtz Charles F. 
Published: February 2021

Abstract
The Carpal Wrist is a novel, parallel-architecture device that exhibits many features desirable in a robotic wrist. Previous static analysis has verified the large, singularity-free workspace and the excellent force-bearing ability of the Carpal Wrist. Here, the parallel structure is shown to be particularly advantageous when considered dynamically due to its lightweight structure and multiple load bearing members. The dynamic equations of motion are derived in closed form by direct application of Lagrange’s equations to the kinematic model. The model assumes a relatively massive tool and includes all gravitational, inertial, and gyroscopic effects. The equations of motion provide closed-form evaluation of the actuation moments based on general tool trajectories.
Optimal Fuel Cell System Design Considering Functional Performance and Production Costs
Authors: Xue Deyi , Dong Zuomin 
Published: February 2021

Abstract
In this work the optimization-based, integrated concurrent design method is extended to a general mechanical system — the transportation fuel cell system. A general optimal design model considering both functional performance and production costs is first introduced. Mathematical models of the functional performance and production costs of the Ballard fuel cell system are then discussed. A joint performance and cost optimization is carried out using the Ballard fuel cell system to demonstrate the approach. The optimization concurrently takes into account of two functional performance aspects and production costs to identify the optimal values of two key design variables. The work is a continuation of the authors’ earlier research on integrated concurrent engineering design.
The Problem of Size in Robust Design
Authors: Koch Patrick N. , Allen Janet K. , Mistree Farrokh , Mavris Dimitri 
Published: February 2021

Abstract
To facilitate the effective solution of multidisciplinary, multiobjective complex design problems, a departure from the traditional parametric design analysis and single objective optimization approaches is necessary in the preliminary stages of design. A necessary tradeoff becomes one of efficiency vs. accuracy as approximate models are sought to allow fast analysis and effective exploration of a preliminary design space. In this paper we apply a general robust design approach for efficient and comprehensive preliminary design to a large complex system: a high speed civil transport (HSCT) aircraft. Specifically, we investigate the HSCT wing configuration design, incorporating life cycle economic uncertainties to identify economically robust solutions. The approach is built on the foundation of statistical experimentation and modeling techniques and robust design principles, and is specialized through incorporation of the compromise Decision Support Problem for multiobjective design. For large problems however, as in the HSCT example, this robust design approach developed for efficient and comprehensive design breaks down with the problem of size — combinatorial explosion in experimentation and model building with number of variables — and both efficiency and accuracy are sacrificed. Our focus in this paper is on identifying and discussing the implications and open issues associated with the problem of size for the preliminary design of large complex systems.
Analysis of the Transmission Error of Face-Gear Drives
Authors: Chung S. D. , Chang S. H. , Lu S. S. 
Published: February 2021

Abstract
Based on the face-gear generation process, the analytical geometry of face-gear drive with its mathematical model for tooth contact analysis of face-gear and spur pinion meshing was derived. In this paper, contact path and transmission error due to assembly misalignment were analyzed by using the proposed mathematical model and the tooth contact analysis. The effect of assembly error along the axis of face-gear, misalignment of crossed and angular displacement between axes of spur pinion and face-gear were all investigated. The results are illustrated by several examples.
The Creation of Assembly Geometry From Functional Definitions
Authors: Brady Doug , Juster Neal P. 
Published: February 2021

Abstract
Modern CAD systems are able to represent the geometry of engineering components proficiently. This aids the later stages of the design process but does not help during conceptual design. This paper outlines a suite of programs known as the Conceptual Assembly Design Tool which allows designers to create outline assembly geometry from function structures, thus providing a potential bridge between conceptual and embodiment design. The paper includes a case study showing how the system may be used during the resign of a moderately complex product.
A Constraint-Based Algorithm for Reasoning About the Shape Producing Capabilities of Cutting Tools in Machined Parts
Authors: Gaines Daniel M. , Hayes Caroline C. 
Published: February 2021

Abstract
The tools and processes available in a given shop greatly influence the way in which manufacturers view a part and the way in which they decompose it into manufacturable volumes (features). It would be very useful to manufacturers to have an automated process planning assistant that would allow them 1) to specify their own, possibly special purpose, and 2) show them the impact that adding those tools will have on the way in which the part can be decomposed into features and on the manufacturing methods that can be used in the process plan. In this paper, we present 1) Tool-Editor, which allows users to enter their own tool shapes in a specification derived from the National Institute of Standards and Technologies’ specification for manufacturing resources; and 2) Tool-Mapper, a method for identifying the regions of the part that each tool can produce and generating a method which describes how the tools can make the identified shapes. If the first stage of traditional process planning can be viewed as translating features into processes, then Tool-Mapper can be viewed as the reverse process in which tools are translated into shapes. The benefit offered by tool-mapping is that it provides a mechanism for allowing users to input tools specific to their shop, without requiring them to reprogram the system, or to perform more knowledge acquisition to determine the impact of changing the tools.
Admissible Tool Orientation Control of 5-Axis Complex Surface Machining for CAD/CAM Systems
Authors: Lee Yuan-Shin 
Published: February 2021

Abstract
This paper presents a methodology and algorithms of admissible tool orientation control for gouging avoidance in 5-axis machining. A method is proposed to find the admissible tool orientation by considering both local and global surface shapes. A filleted endmill is used in this study for 5-axis machining. Based on the evaluation of local surface shape, a geometry analysis method is developed to first find a feasible tool orientation for gouging avoidance along two orthogonal cutting planes. Adjacent geometry is then taken into consideration for detecting possible rear gouging. A localization algorithm is developed for filleted endmills to identify potential rear gouging area. Both the circular approximation and the detailed gouging checking methods are proposed for rear gouging correction. The techniques presented in this paper can be used to eliminate errors of tool paths as they are generated. Unlike the traditional graphical verification and user-interactive correction of tool path generation, the proposed methodology can be used to automate the planning and programming of cutter path generation for 5-axis machining.
Concurrent Decomposition for Sheet-Metal Products
Authors: Wang Cheng-Hua , Bourne David A. 
Published: February 2021

Abstract
During the product development stage, designers often face the task of partitioning a product into functioning parts. Unfortunately, most decomposition decisions are made based on product functionality while the product manufacturability is usually ignored. As a result, the resulting parts can be too expensive to manufacture or sometimes impossible to make.
In this paper, we present a systematic approach to help designers decompose sheet-metal products. This approach is primarily driven by product manufacturability. It takes into account the manufacturability of sheet metal cutting, bending and assembly processes, while trying to minimize the number of parts. To overcome the combinatorial nature of the decomposition problem, a develop-first-decompose-later strategy is used. The decomposition goes back and forth between the design and decomposition modules to achieve sub-optimal results. The decomposition results are sent to the corresponding process planners and a complete production plan is produced.
A prototype system has been developed to demonstrate the proposed approach. Several decomposition examples are also presented.
Process Planner’s Assistant: An Interactive and Iterative Approach to Automating Process Planning
Authors: Li Xiaomin , Kambhampati Subbarao , Hirode Kartheek , Shah Jami 
Published: February 2021

Abstract
Most existing approaches to computer aided process planning aim for full automation by searching for a plan that is optimal with respect to a pre-specified objective function. Such full automation is often infeasible in practice for three reasons: (i) the search space of potential plans is huge, (ii) optimality metrics are often context sensitive and can only be elicited through user interaction, (iii) because of the importance of process planning, organizations are more interested in process planning assistants that support human expert process planners rather than standalone process planners.
In this paper, we present a “process planner’s assistant”, which helps the human process planning experts in coming up with process plans. In order to achieve this, the process planner’s assistant must have access to the full search space of process plans, and the ability to modify plans in response to human criticism. The former is provided by basing our system on ASU Features Testbed, a comprehensive and systematic framework for recognizing and reasoning with features in machinable parts. To support the latter, the system is equipped with an incremental and interactive search mechanism. We will discuss the operational details of the resultant system, called ASUPPA.
The Process Capability Matrix: A Tool for Manufacturing Variation Analysis at the Systems Level
Authors: Frey Daniel D. , Otto Kevin N. 
Published: February 2021

Abstract
This paper introduces the concept of a process capability matrix — an ordered set of dimensionless parameters that capture information on a manufacturing system’s response to noises. The matrix captures information on the magnitude of noise, sensitivity to noise, and tolerance to variation. Algorithms and equations are presented that use the matrix to compute the yield of a manufacturing system. The method proves to be accurate on real engineering problems for which existing techniques are inadequate due to statistical correlation among product acceptance criteria. The process capability matrix also proves useful in a new type of block diagram of production systems. The block diagrams are shown to be useful in evaluating the effectiveness of feedforward control strategies for variation reduction. An electronics assembly process serves as an example of the algorithms and their use in design decision making.
A Case Study in Multi-Disciplinary Distributed Collaborative Design
Authors: Riesenfeld Richard , Fish Russell , Drake Samuel 
Published: February 2021

Abstract
Researchers at the University of North Carolina at Chapel Hill and the University of Utah participated in a collaborative, remote, rapid design and manufacturing experiment. Several domain experts at widely distributed geographical locations worked on a challenging multi-disciplinary design problem producing a rugged, compact and light-weight housing for a Video See-Through Head-Mounted Display to be used in image-guided surgical procedures. This was used as a case study to validate and motivate ongoing research in a distributed engineering design and manufacturing system.
The hypothesis was that Net-based use of a highly supportive integrated, collaborative design and manufacturing environment would dramatically expedite the design and manufacturing process. Using the already existing Alpha_1 design and manufacturing environment as a platform, we embarked on a project to collapse the normal six-month cycle of design and prototype iterations into a single three-week period of collaborative design. The lessons learned demonstrate the potential success of the hypothesis, and also provide a basis for further research into tools and environments needed to support integrated collaborative design, engineering, and manufacture.
We discuss the results of the experiment, application of the existing distributed design system, the supporting system architecture, and possible future research issues brought to light by the experiment.