bluuebunny/crossref_metadata_2025 huggingface dataset:
First Order Analysis for Automotive Body Structure Design
Authors: Nishigaki Hidekazu , Nishiwaki Shinji , Amago Tatsuyuki , Kikuchi Noboru
Published: December 2020

The concept of Computer Aided Engineering (CAE) was first proposed by J. Lemon at SDRC, and has been widely accepted in automotive industries. CAE numerically estimates the performance of automobiles and proposes alternative ideas that lead to the higher performance without building prototypes. However, most automotive designers cannot directly utilize CAE since specific well-trained engineers are required to achieve sophisticated operations. Moreover, CAE requires a huge amount of time and many modelers to construct an analysis model. In this paper, we propose a new concept of CAE, First Order Analysis (FOA), in order to overcome these problems and to quickly obtain optimal designs. The basic ideas include (1) graphic interfaces for automotive designers using Microsoft/Excel (2) use of sophisticated formulations based on the theory of mechanics of material, (3) the topology optimization method. Further, some prototypes of software are presented to confirm the method for FOA presented here.
A Study on Optimum Topology Using Conformal Mapping
Authors: Kitayama Satoshi , Yamakawa Hiroshi
Published: December 2020

This paper presents a method to determine optimum topologies of two dimensional elastic planar structures by using conformal mappings. We use the conformal mappings which is known to be effective in two dimensional fluid mechanics, electromagnetics and elasticity by complex coordinate transformation. We show that two invariants of stress can satisfy the Laplace equation, and then we clarify that corresponding relationships between fluid mechanics and electromagnetics can also be valid in the theory of elasticity. Then, presented a method to obtain optimum topologies is easier than by the conventional methods. We treated several numerical examples by the presented method. Through numerical examples, we can examine the effectiveness of the proposed method.
Design for Production: A Tool for Reducing Manufacturing Cycle Time
Authors: Herrmann Jeffrey W. , Chincholkar Mandar M.
Published: December 2020

This paper describes a decision support tool that can help a product development team reduce manufacturing cycle time during product design. This design for production (DFP) tool determines how manufacturing a new product design affects the performance of the manufacturing system by analyzing the capacity requirements and estimating the manufacturing cycle times. Performing these tasks early in the product development process can reduce product development time. The paper presents a comprehensive DFP approach and describes the components of the DFP tool, which gives feedback that can be used to eliminate manufacturing cycle time problems. We present an example that illustrates the tool’s functionality.
A Tool-Centric Approach to Generating Redesign Suggestions for Improved Machinability
Authors: Zhou Xuhui , Gaines Daniel M.
Published: December 2020

Providing early feedback on the manufacturability of a part design can greatly improve the quality of the product while reducing the time and cost of production. However, the necessary manufacturing knowledge is not always available. Computer tools that can provide this manufacturing knowledge by analyzing a design suggesting changes to improve its manufacturability would be a valuable asset to a designer. To this end, we present an approach to automatically generate redesign suggestions to improve the manufacturability of machined parts. Novel aspects of this approach include the ability to identify un-machinable shapes in a part and transform them into machinable features and to automatically identify the possible shape transformations based on properties of the machining equipment. This increases the scope of redesign generation tools by allowing them to be applied to parts that are not already machinable.
A Survey on Design Rationale: Representation, Capture and Retrieval
Authors: Hu Xiaochun , Pang Jun , Pang Yan , Atwood Michael , Sun Wei , Regli William C.
Published: December 2020

This paper provides a brief survey on recent research in the area of design rationale. The study of Design Rationale spans a number of diverse disciplines, touching on concepts from research communities in Mechanical Design, Software Engineering, Artificial Intelligence, Civil Engineering and Human-Factors and Human-Computer Interaction research. We focus this survey on prototype design rationale systems for these application domains and put forward several major axes along which to describe and classify design rationale systems, including argumentation-based, descriptive, and process-based approaches. Further, we attempt to abstract the place of systems and tools for design rationale capture and retrieval in the context of contemporary knowledge-based engineering and CAD tools.

This survey is structured around the fundamental different approaches, their representation schema, their capture methods, and retrieval techniques. A number of recent design rationale systems and representation schemes are presented, including JANUS, COMET, ADD, REMAP, HOS, PHIDIAS, DRIVE, IBIS. We conclude with an assessment of the current state-of-the-art and a discussion of critical open research issues.
Information Modeling of Conceptual Process Planning Integrated With Conceptual Design
Authors: Feng Shaw C. , Song Eugene Y.
Published: December 2020

Conceptual process planning is a key activity for designers to evaluate manufacturability and manufacturing cost and time in the early product development stage. Since major manufacturing cost is determined in early design, it is critical to be able to assess manufacturability and cost as early as possible in the design process. The integration between process planning and design is critical to enable these analyses. A literature review of the current status of Computer-Aided Design (CAD) and Computer-Aided Process Planning (CAPP) software technologies reveals the lack of interface standards to enable the integration of these systems. In order to develop interface standards, information models have to be first developed to define the interfaces. An initial information model for conceptual process planning has been developed. This model includes an activity model and an object model for manufacturing process selection, resource selection, and cost and time estimation. The activity model sets the context in which the objects are used for information sharing and exchange. The object model defines classes used in conceptual process planning. The main purpose of developing this model is to initiate the development of standard interface specifications that are necessary for design and process planning integration.
Recognition of Contact States: Validation of Planning With Principal Contacts (PCS)
Authors: Marehalli Jayavardhan N. , Sturges Robert H.
Published: December 2020

In high precision assembly tasks, contact motion is common and often desirable. These events entail a careful study of contact states of the parts being assembled. Recognition of contact states is crucial in planning and executing contact motion plans due to inevitable uncertainties. Xiao [3] introduced the concept of principal contacts (PC) and contact formation (CF) for contact state recognition. The concept of using CFs (as sets of PCs) has the inherent advantage that a change of CF is often coincident with a discontinuity of the general contact force (force and torque). Previous work [1,2] in contact motion planning has shown that contact information at the level of PCs along with the sensed location and force information is often sufficient for planning high precision assembly operations. In this paper, we present results from experiments involving planned contact motions to validate the notion of PCs and CFs, specifically that an abrupt change in general contact force often accompanies a change between CFs. We present results for the general 2D peg-in-corner problem.
Robustness Evaluation for Compliant Assembly Systems
Authors: Lee Jinkoo , Long Yufeng , Hu S. Jack
Published: December 2020

A new method for evaluating the robustness of compliant assembly systems is developed based on previously developed variation simulation models. This method can be used for selecting a robust assembly system at product/process development stage. Examples are presented to illustrate the proposed method.
Optimising Automatic Tool Selection for 2½D Components
Authors: Lim T. , Corney J. , Ritchie J. M. , Clark D. E. R.
Published: December 2020

An important step in planning the manufacture of a component by CNC machining is the selection of cutting tools. Although it has long been known that the choice of cutter sizes can have a dramatic effect on the overall machining time, few algorithms for optimisation have been available to the production engineer. This paper describes a method for determining a theoretical optimal combination of cutting tools for machining a given set of 3D volumes or 2D profiles. The algorithm considers residual material left behind by oversized cutters and the relative clearance rates of cutters that can access the selected machining features. The current implementation of the procedure described does not give exact results because several machining parameters are not included in the selection process such as tool path length, plunge rates, etc. However, the experimental results suggest that while these factors may make changes to the absolute values calculated, they typically make only a small difference to the relative ranking of the tools. The results presented here suggest that the correct combination of tools could reduce machining times by significant amounts. Consequently the paper concludes with a discussion of how the tool path generation routines used in commercial CAM systems could be modified to achieve this.
A Web-Based Tolerance Analysis Service for Solid Freeform Fabrication
Authors: Arni R. K. , Gupta S. K. , Kumar Malay
Published: December 2020

This paper describes a prototype web-based service for performing manufacturability analysis of design tolerances for parts produced using solid freeform fabrication processes. Our prototype service primarily serves two different types of users — process providers and designers. Process providers register the process capabilities and constraints of their processes with the service. Designers upload the geometry and tolerance information of the part to our server and select a process from the list of registered processes and perform an analysis of the feasibility of manufacturing the part using the selected process. Manufacturing feasibility is identified by analyzing the effect of build direction on the achievable tolerances on various faces of the part. If there is at least one build direction that can satisfy all tolerance requirements, then the part is considered manufacturable. Otherwise, the part is considered non-manufacturable. In this paper, we describe the architecture of our prototype service and explain in detail the process of registering process capabilities and performing manufacturability analysis using our prototype service. We also describe an algorithm to formulate redesign suggestions that can propose suitable modifications to the part design so that a non-manufacturable part can become manufacturable.
Decomposition Based Feature Recognition Using Constrained and Aggregated Half-Space Partitioning
Authors: Lu Yong , Gadh Rajit , Tautges Timothy J.
Published: December 2020

Decomposition based feature recognition (DBFR) has drawn attention over the years. It has two stages: decomposition and aggregation. At the decomposition stage, the CAD model is partitioned into minimal cells. At the aggregation stage, the decomposed individual cells are composed in different combinations and these combinations are matched with predefined feature patterns to retrieve features in the model. The DBFR technique shows promises to deal with interactive features. However, DBFR algorithms suffer from the combinatorial problem in both the partitioning and the composing stages. This paper proposes a novel decomposition based feature recognition technique using the constrained and aggregated half-space partitioning. The constrained and aggregated half-space is defined in the occupation of a volume in the Euclidean space, bounded by multiple surfaces. The decomposition approach based on this concept can largely avoid over-cuttings. It tends to produce partitions that can be directly matched with feature patterns. Different from other DBFR algorithms, pattern matching is also introduced in the decomposition stage. Thus it further shrinks the space of combination and feature determination. Some algorithms are also proposed to do efficient volume combinations at the aggregation stage.
Graph Grammar Based Product Variety Modeling
Authors: Du Xuehong , Tseng Mitchell M. , Jiao Jianxin
Published: December 2020

This paper discusses the issue of product variety modeling, i.e. the means to organize the data of a family of products according to the underpinning logic among them. The targeted product families are characterized by providing user-selectable product features and feature values and achieving variety by combining parameterized functional or physical modules. A graph grammar based (GGB) model is proposed for the purpose of enhancing the comprehensiveness and manipulability of the data of product families for different functional departments in a company in order to facilitate effective order processing as well as direct customer-manufacturer interaction. To deal with variety effectively, both structural and non-structural family data are represented as family graphs whereas order-specific products are represented as variant graphs derived by applying predefined graph rewrite rules to the family graphs. The most important characteristics of the GGB model are three folds. While emphasizing the distinctiveness of the information that different users are concerned about, it provides cross view data transferring mechanisms. It also supports data manipulation for variety generation. Finally, taking advantage of the graph grammar based language of PROGRES, GGB is a model to be easily implemented as a visualized computer system. The specification of an office chair product family illustrates the principles and construction process of GGB models.
Performance Distribution Analysis and Robust Design
Authors: Zhu Jianmin , Ting Kwun-Lon
Published: December 2020

The paper presents the theory of performance sensitivity distribution and a novel robust parameter design technique. In the theory, a Jacobian matrix describes the effect of the component tolerance to the system performance, and the performance distribution is characterized in the variation space by a set of eigenvalues and eigenvectors. Thus, the feasible performance space is depicted as an ellipsoid. The size, shape, and orientation of the ellipsoid describe the quantity as well as quality of the feasible space and, therefore, the performance sensitivity distribution against the tolerance variation. The robustness of a design is evaluated by comparing the fitness between the ellipsoid feasible space and the tolerance space, which is a block, through a set of quantitative and qualitative indexes. The robust design can then be determined. The design approach is demonstrated in a mechanism design problem. Because of the generality of the analysis theory, the method can be used in any design situation as long as the relationship between the performance and design variables can be expressed analytically.
Direct Machining: A New Paradigm for Machining Data Transfer
Authors: Bassett C. P. , Jensen C. G. , Bosley J. E. , Red W. E. , Evans M. S.
Published: December 2020

Although modern machine tools and controllers have evolved with the computer over the years, many machining practices derive from those developed for the original punched-tape controllers. A new method called Direct Machining And Control (DMAC) is being developed at Brigham Young University that allows the machine controller to directly interpret the CAD/CAM models without the need for any intermediary text files such as M&G code. In this paper, Direct Machining with its requirements and implications is explored. CAD extraction methods and progress are shown. Our software architecture and data transfer methods are explained. With what we have developed, we can build a proof-of-concept system that will hopefully attract the attention and partnership of both CAD and machine controller vendors for further integration.
An Analysis of the Content of Technical Information Used by Engineering Designers
Authors: Lowe Alistair , McMahon Chris , Shah Tulan , Culley Steve
Published: December 2020

This paper reports on an investigation that aims to characterise the technical content of documentary information used by engineers within two aerospace companies. The work has been carried out in order to gain an understanding of the technical requirements for future information systems to support designers. A rigorous analysis of the textual content of exemplar information objects provided by engineers is initially described. From this analysis, Object Content Profiles for three distinct types of text-based objects are identified: (i) correspondence, (ii) technical (report) objects and (iii) manuals, catalogues and standards. This work is complemented by a survey of designers which identifies the attributes that engineers consider the most helpful as search criteria when trying to locate information objects. These results suggest that whilst drawings and CAD models can be represented by a small number of core attributes, for text-based objects a wider range of descriptive attributes is important. Finally, an outline framework to allow the development of hierarchical taxonomies is presented. This is based on ontology development guidelines but is modified to promote the reuse of existing hierarchically structured sources of indexing terms.
Managing Dependencies for Collaborative Design
Authors: Wang Kai-Lu , Jin Yan
Published: December 2020

In collaborative engineering, the dependencies of engineering problems determine with whom and how designers should coordinate. Based on the directed dependency framework introduced in this research, we argue that the reciprocal and cyclic dependencies cause design iterations and inefficiencies, and should be avoided if possible. By studying the patterns of engineering dependencies and design decomposition, this paper provides an approach to manage the dependencies in order to avoid reciprocal and cyclic dependencies both in the early conceptual design stage and in design task arrangement stage, to make collaborative design more efficient. The long-term goal of this research is to develop a dependency-based coordination framework that consists of a formal model of engineering dependencies, and coordination methods, and guidelines for dependency-based engineering design and management. This paper describes our current dependency modeling framework and dependency management methods for collaborative design.
Designing Modular and Integrative Systems
Authors: Sosa Manuel E. , Eppinger Steven D. , Rowles Craig M.
Published: December 2020

This paper describes a method that allows us to enhance our understanding of the difference between designing modular systems and integrative systems. Modular systems are those whose interfaces are well defined and shared with only a few other systems. Integrative systems are those whose interfaces may be more complex and shared across the product. Our approach is illustrated by analyzing the development of a large commercial aircraft engine. We document both the product’s design interfaces and the technical interactions between design teams. We found statistically significant differences in the ways modular and integrative design teams handle design interfaces. We focus our analysis on studying the effects due to organizational and system boundaries, and to the existence of various types of design interfaces. By identifying modular and integrative systems and by understanding the differences in designing those systems, development organizations can improve the integration process for complex designs.
Information Handling and Social Interaction of Multi-Disciplinary Design Teams in Conceptual Design: A Classification Scheme Developed From Observed Activity Patterns
Authors: Milne Andrew J. , Leifer Larry J.
Published: December 2020

Economical “intelligent” technologies emerging from the fields of electrical engineering, materials science, and computer science are making product design an increasingly multi-disciplinary activity. Collaboration among disciplinary specialists is particularly important in the early phases of the design process, when alternative technology strategies are considered and initial solution approaches are planned. In an effort to design new forms of technology-supported global learning spaces, Stanford University sponsored a design charrette, bringing together participants from a variety of disciplines to develop design requirements for both the technological and physical architecture of such spaces. The design activity was videotaped and later analyzed in an attempt to understand how design teams were using information and how much emphasis each team placed on information handling activity vs. social interaction. One outcome of this work was the development of a coding scheme that can be applied to analyze activity of design teams during the early phases of conceptual design. Another outcome was a quantitative analysis of the design activity. The analysis of two design teams with apparently very different process approaches revealed similar activity patterns. It also showed a rather even distribution within each team between “information introduction” activities and “process navigation” activities. The results demonstrate the importance of detailed, structured analysis of design team activity and suggest opportunities for future research in this area.
Multi-Objectives Layout Planning Approach
Authors: Sallam Mohamed M. , Ashour Said A. , El-Sharief Mahmoud A.
Published: December 2020

Plant layout deals with selection of the most effective arrangement of facilities or departments to achieve the best utilization of the available resources to produce a product. The plant layout problem is of great interest to both scholars and practitioners. Historically, two basic criteria have been most commonly used to generate an optimum layout. These two criterions are quantitative and qualitative.

In this study an approach is introduced as a heuristic technique for combining the quantitative and qualitative aspects of the facility layout. The two objectives which may be contradicting, are minimizing material handling costs and maximizing a closeness rating measure. Assuming that the decision-maker is capable of responding to a paired comparison of alternatives, this algorithm is developed to, iteratively, reduce the feasible space of the weighting factor, which combines the two objectives. The algorithm terminates when the predetermined bounds on the weighing factor are reached. A graphical method is presented to help analyze the sensitivity of the optimum layout into small variations in the estimated value of the decision-maker’s preferred weight.

The proposed approach has been applied in a case study, which is an exhaust system factory (Engineering Company for Manufacturing Exhaust Systems) located in the 6th. October City. This factory was founded as a small workshop for producing hand-made mufflers to meet the needs of the local automotive repair shops. In order to satisfy the needs of assembly plants of exhaust systems, a new location in the 6th. October City has been chosen, modern machinery supplied and scientific techniques followed to accomplish optimum layout. By applying this approach the best layout can be generated. In this layout warehouses were rearranged and a reduction the total material handling costs of 32% has been achieved.
Overconstrained Analysis of Five-Link Spatial Single Loops With Revolute and Prismatic Joints
Authors: Jin Qiong , Hang Lu-Bin , Zhang Ming
Published: December 2020

A new method on determining the existence conditions of overconstrained mechanisms is presented in this paper, which is used for studying the spatial single loop generally possessing one configure. This method is very effective to distinguish finite and infinite solutions of displacement analysis, and can analytically deduce the input-output equations. It is elucidated that the existence conditions of overconstrained mechanism consist of the overconstrained conditions and the closure conditions, and that the independence of the closure conditions should be further discussed. On the other hand, the existence conditions of two known 5-link overconstrainded mechanisms are verified and corrected. This method also provides a theoretical basis for finding new oveconstrained mechanisms.
Assembly Configurations of Spatial RRRCC, RRCRC, RRRRCR, and RRRRRRR Mechanisms
Authors: Foster David E. , Cipra Raymond J.
Published: December 2020

This paper examines the problem of finding the assembly configurations, also called circuits, of spatial single-loop single-DOF mechanisms with five or more links. The RRRCC, RRCRC, RRRRCR, and RRRRRRR mechanisms are covered, along with all variations in which a revolute (R) joint is replaced by a prismatic (P) joint. A numerical method is given to find the ACs, and is illustrated with several examples.
Computational and Geometric Investigation on the Reciprocal Screw Axis of Bricard Six-Revolute Mechanisms
Authors: Lee Chung-Ching
Published: December 2020

Based on the optimization theory and the direct elimination technique, we present a systematic approach to explore the single reciprocal screw axis of Bricard six-revolute mechanisms numerically and to confirm its geometric properties graphically. To overcome the difficulty of deriving the analytical closed-form solutions and the shortcomings of needing an accurate initial estimate and having a highly computational sensitivity in the popular Newton-type procedure, the nonlinear programming algorithm establishes a general computational solution to the matrix displacement equation. Using the transformation of line and screw coordinates and the fundamentals of reciprocity of screws, we develop a simple numerical computational approach to obtain the reciprocal screw axis of mechanisms through the linear dependence or independence of linear algebra. Geometric explanations with 3-D computer graphics are also offered to comprehensively understand their algebraic surface of the reciprocal screw axes and to confirm the correctness and validity of the derived algorithm.
Finding Diversity in Mechanisms Using a Hybrid Genetic Algorithm
Authors: O’Neil Robert A. , Everett Louis J.
Published: December 2020

The path synthesis problem for mechanical linkages still presents problems for engineers, although it has been examined for more than two centuries. This research approached the design problem as one of creating a characteristic test function to compare a synthesized output path with a desired output path, and finding a set of linkages that reduce the corresponding error. Since the solution space of this approach is very large with typically a generous number of local minima, it may be possible to find several linkages that each produce a small error. This research investigated the ability to use a modified genetic algorithm to search for a global minima and simultaneously identify several linkage designs that are “almost” as good as the global optimum. Having alternative solutions will allow designers to choose a mechanism that best fits criteria other than path error. The results from using the method on a subclass of linkage problems demonstrate that solutions can be found that “fit” better than those found in the literature. The results also show that a diverse family of acceptable designs can be obtained and that this family includes both “well known” designs and heretofore unknown solutions.
Workspace Generation As a Diffusion Process
Authors: Wang Yunfeng , Chirikjian Gregory S.
Published: December 2020

In this paper we show that the workspace of a highly articulated manipulator can be found by solving a partial differential equation. This diffusion-type equation describes the evolution of the workspace density function depending on manipulator length and kinematic properties. The support of the workspace density function is the workspace of the manipulator. The PDE governing workspace density evolution is solvable in closed form using the Fourier transform on the group of rigid-body motions. We present numerical results that use this technique.
Numerical Study of the Motion of a Runaway Escapement
Authors: Els D. N. J.
Published: December 2020

The dynamic and kinematic characteristics of a runaway escapement, one of the classic mechanisms, were investigated. The two components of the mechanism are treated as separate entities and their equations of motion are integrated twice to obtain angular displacement. The motion is constrained by the space occupied by the opposing component at a specific time. The contacts between the components are treated as elastic collisions with dissipation and friction.

From the simulation results it can be concluded that for the normal operating range of a runaway escapement, a resisting moment proportional to the square of its angular velocity is exerted.
SDAMP: Software for the Design and Analysis of Mechanical Presses
Authors: Stumph Herbert E. , Murray Andrew P.
Published: December 2020

In this paper we introduce the MATLAB-based SDAMP (pronounced stamp) software for the analysis and synthesis of several mechanical press linkages. These linkages include the slider-crank and the four six-bar mechanisms formed by attaching a drag-link, crank-rocker, crank-shaper or Whitworth mechanism to a slider-crank. SDAMP performs four basic tasks: guided layout, kinematic analysis, mechanism refine and kinematic synthesis. Guided layout leads the user through joint selection to ensure a functioning mechanism. Kinematic analysis displays the position, velocity, acceleration and jerk of the sliding output versus the rotation of the input link. Mechanism refine allows the user to vary the geometry of an existing mechanism towards the goal of achieving a desired kinematic analysis. Lastly, kinematic synthesis determines the set of defect-free slider-cranks capable of achieving four precision points. All of these capabilities are integrated through a host of GUI driven MATLAB files in SDAMP.
Design and Fabrication of a Gravity Balanced Planar Mechanism Using Auxiliary Parallelograms
Authors: Agrawal Sunil K. , Gardner Glenn , Pledgie Stephen
Published: December 2020

Exercise machines are becoming increasingly popular in rehbilitation and physical therapy. Gravity balancing is an important feature that is sought after in rehabilitative machines in order to make these accessible to patients with low muscular ability. Often, gravity loads in a mechanism are compensated by feed-forward actuator efforts that quasi-statically balance the mechanism in a configuration and are applied in addition to the actuator efforts required to perform a task. Such a scheme works but places large demands on the actuators. Also, actuator efforts are required at every joint in order to keep the mechanism balanced.

This paper describes the design and fabrication of a gravity balanced planar mechanism, where auxiliary parallelograms are used to identify the center of mass of the augmented mechanism. A sliding carriage positions a counterweight directly above the center of mass in order to make the system gravity balanced. The sliding carriage uses joint encoder data to compute the location of the center of mass. Experiment results are presented which demonstrate the effectiveness of the approach.
Active Vibration Control for the Closed Loop Flexible Mechanisms Combined the Feedback and Feed-Forward Strategy: Part 1 — Modelling
Authors: Xianmin Zhang , Changjian Chao
Published: December 2020

A methodology for suppressing the elastodynamic response of high speed closed loop flexible mechanisms with piezoelectric actuators and sensors are developed. In this part, a mixed variational approach with Hamilton’s principle is developed to derive the equations of motion for the closed loop flexible mechanism systems which describes the motion of the mechanisms and the behavior of the piezoelectric apparatus. This model includes both the rigid-body and the elastic motion coupling terms and the elasto-dynamics and piezoelectricity coupling terms as well as the effects of the actuators and sensors upon the mass and stiffness of the system.
Theory and Method of Dynamic Modeling for Multilayer Vibration Isolation System
Authors: Dao-Xun Liao , Yong-Zhong Lu , Xiao-Cheng Huang
Published: December 2020

The multilayer vibration isolation system has been widely applied to isolate vibration in dynamic devices of ships, high-speed vehicles forging hammer and precise instruments.

The paper is based on the coordinate transformation of space general motion for mass blocks (rigid bodies) and Lagrangian equation of multilayer vibration isolation system. It gives a strict mathematical derivation on the differential equation of the motion for the system with six degrees of freedom of relative motion between mass blocks (including base). The equations are different from the same kind of equations in the reference literatures. It can be used in the floating raft of ships in order to isolates vibration and decrease noise, also used in design calculation of the multilayer vibration isolation for dynamic machines and precise instruments on the dry land.
A Parametric Study of the Dynamics of the Shudderless Tripode Joint
Authors: Santonocito Paolo , Pennestri Ettore
Published: December 2020

Front-wheel drive cars rely upon tripode joints, well known and widely used spatial mechanisms. This research has been prompted by the appearance on the market of a shudderless tripode joint. By means of a parametric model, based on the application of a multibody dynamics technique, it has been investigated the influence of geometric variables and angular speed on the amount of constraint forces and torque fluctuations. The numerical examples presented provide practical guidelines for a rational choice of such parameters.
A New Design Method for Spatial Vibration Absorbers
Authors: Blanchet Pat , Lipkin Harvey
Published: December 2020

A new methodology is presented for the design of spatial vibration absorbers. In general, the design of vibration absorbers has been limited to systems excited by a pure force. These designs cannot handle excitations composed of both a force and a torque. Furthermore, that design requires the absorber to be along the line of action of the force. The proposed design method is more versatile since the location of the absorber is left as a design freedom and it places no restriction on the type of excitation.
The Design Considerations of Manipulators
Authors: Tsai K. Y. , Huang K. D.
Published: December 2020

This paper presents algorithms to evaluate various kinematic properties of manipulators and then studies how to utilize the obtained result in the design of manipulators. The manipulability, workspace volume, and force transmissivity of various serial chains are first evaluated. The obtained data are compared and listed on tables that can be used for designing serial and in-parallel manipulators. A modular approach is used for designing in-parallel manipulators. The optimum design of the platform and serial chains are obtained independently. The modules are then assembled into in-parallel manipulators according to the rules proposed in this work.
Kinematic Synthesis of Spatial in-Parallel Wire-Driven Mechanism With Six Degrees of Freedom With High Force Transmissibility
Authors: Takeda Yukio , Funabashi Hiroaki
Published: December 2020

We propose an index for evaluating the force transmission characteristics in general N degree-of-freedom (dof) in-parallel wire-driven mechanisms (PWDMs) with N + 1 wires. The relationship between input force and output force in an N dof in-parallel actuated mechanism with only rigid links was used for defining the transmission index for a PWDM. The index has been applied to the kinematic synthesis of spatial six dof PWDM with seven wires, and novel PWDMs with high force transmissibility have been obtained.
Determination of the Uniqueness Domains of 3-RPR Planar Parallel Manipulators With Similar Platforms
Authors: Kong Xianwen , Gosselin Clément M.
Published: December 2020

A uniqueness domain is a part of the Cartesian workspace corresponding to the same assembly mode of the 3-RPR (planar parallel) manipulator. This paper presents an efficient method to determine the uniqueness domains of the 3-RPR manipulators with similar platforms. The method is based on the singularity and forward displacement analysis (FDA) of the 3-RPR manipulator with similar platforms. The singularity analysis and the FDA of the 3-RPR manipulator with similar platforms is first performed. It is then proved that each of the solutions distributes into different singularity-free regions of the manipulator. Each singularity-free region corresponds to one uniqueness domain of the 3-RPR manipulator with similar platforms which can thus be determined in a direct way. At last, it is proved that the four solutions in analytic expression form to the forward displacement analysis correspond to different uniqueness domains for the 3-RPR manipulator with similar aligned platforms. This simplifies further the FDA in this case as the unique solution to the FDA can be found without the need to compute all the four solutions as long as the singularity-free region in which the manipulator works is given.
A Parallel Six Degrees-of-Freedom Inflatable Robot
Authors: Ben-Horin (Dombiak) Patricia , Shoham Moshe , Grossman Gershon
Published: December 2020

A new structure of a six degrees-of-freedom robot is described in this paper. The robot presents two new features: three inflatable links that constitute the robot structure and parallel robot architecture with large workspace. These features result in a lightweight and easy to deploy robot. The structure, kinematics and path planning of the experimental robot are presented.
Singular Configuration and Workspace of a Parallel Manipulator With New Architecture
Authors: Fattah Abbas , Oghbaei Mojtaba
Published: December 2020

In this paper singularity analysis and workspace of a 3DOF parallel manipulator with new architecture are studied. Singular configurations of the manipulator at hand are analysed first. To this end, upon differentiating the kinematic constraint equations of the manipulator with respect to time, the relation between input and output speeds is obtained in terms of two kinds of Jacobians. These two Jacobians are then used to determine singular configurations. Next the workspace of the manipulator is studied from two points of view.
Dynamic Modeling and Simulation of Parallel Mechanisms Using the Virtual Spring Approach
Authors: Wang Jiegao , Gosselin Clément M. , Cheng Li
Published: December 2020

A new approach for the dynamic simulation of parallel mechanisms or mechanical systems is presented in this paper. This approach uses virtual springs and dampers to include the closed-loop constraints thereby avoiding the solution of differential-algebraic equations. Examples illustrating the approach are given and include the four-bar mechanism with both rigid and flexible links as well as the 6-dof Gough-Stewart platform. Simulation results are given for the four-bar linkages and the 6-dof manipulator. The results achieve a good agreement with the results obtained from other conventional approaches.
In-Parallel Passive Compliant Coupler for Robot Force Control
Authors: Dwarakanath T. A. , Crane Carl D. , Duffy Joseph , Tyler Chad
Published: December 2020

This paper describes the design of a Passive Compliant Coupler for Force Control (PCCFC) based on an in-parallel mechanism. The optimal synthesis of the mechanism is performed with the objective of achieving a good quality index. The novel design of the connector (also termed as the leg), a crucial element of the mechanism, is one of the important features of the paper. The shape optimization of connectors of an in-parallel mechanism is obtained by satisfying compliant requirements and considering maximization of signal to noise ratio criteria. The various design aspects of sizing, sensing the displacement, and implementation of the connector are discussed. The in-parallel compliant mechanism for force control is obtained by optimizing the signal to noise ratio at various stages of the mechanism design.
Modeling and Batch Fabrication of Spatial Micro-Manipulators
Authors: Kimball C. , Tsai L. W. , DeVoe D. , Maloney J.
Published: December 2020

Pseudo rigid body models (PRBM) may be used to accurately and efficiently model the large elastic deflections of compliant mechanisms. Previously published models have only considered end forces with no end moment or end moment acting only in the same direction as the force. In this paper, we present a model for a cantilever beam with end moment acting in the opposite direction as the end force causing an inflection point. As motivation for the development of such models, we present a novel spatial micro-manipulator which can be modeled with this PRBM. This micro-manipulator is being fabricated as a MEMS device using a 3D fabrication process.
Optimization-Based Design of a Fully-Compliant Bistable Micromechanism
Authors: Parkinson Matthew B. , Jensen Brian D. , Roach Gregory M.
Published: December 2020

Micro-bistable mechanisms are used in microswitches and microvalves to reduce power consumption as power is applied only to switch states. Many of the bistable mechanism designs that have been presented incorporate rigid-body joints. These joints introduce unwanted friction and poor repeatability into the mechanism motion. A fully-compliant mechanism avoids these problems. Optimization techniques were used to find fully-compliant bistable micromechanism designs. The chosen objective was to minimize the displacement required between the two stable positions. Two families of designs were considered: those where the actuator was integral to the device and those where it remained in contact only during actuation. Mechanism designs are presented and are currently in the process of fabrication.
Two Spatial Gravity Equilibrators
Authors: Herder Just L. , Tuijthof Gabriëlle J. M.
Published: December 2020

This paper describes the design of two spatial gravity compensation devices. The one is an arm-like structure with the same mobility (4dof) as the human arm, which is balanced by two springs. The other is a general suspension unit with full (6dof) mobility, balanced by a single spring. When link and spring masses are considered, rather than just the payload, the latter configuration needs an additional spring or a slight alteration of its structure for complete balance.
Design and Modeling of an Electro-Rheological Fluid Based Haptic Interface
Authors: Mavroidis C. , Pfeiffer C. , Celestino J. , Bar-Cohen Y.
Published: December 2020

In this project, Rutgers University has teamed with the Jet Propulsion Laboratory (JPL) to pursue the development and demonstration of a novel haptic interfacing capability called MEMICA (remote MEchanical MIrroring using Controlled stiffness and Actuators). MEMICA is intended to provide human operators intuitive and interactive feeling of the stiffness and forces at remote or virtual sites in support of space, medical, underwater, virtual reality, military and field robots performing dexterous manipulation operations. The key aspect of the MEMICA system is a miniature Electrically Controlled Stiffness (ECS) element that mirrors the stiffness at remote/virtual sites. The ECS elements make use of Electro-Rheological Fluid (ERF), which is an Electro-Active Polymer (EAP), to achieve this feeling of stiffness. Forces applied at the robot end-effector due to a compliant environment will be reflected to the user by this ERF device where a change in the system viscosity will occur proportionally to the force to be transmitted. This paper describes the analytical modeling and experiments that are currently underway to develop an ERF based force feedback element.
Configuration Management for Modular Flexible Small Automation Systems: A Case Study
Authors: Turner Cameron J. , Legault Jacy M. , Cox Dan J.
Published: December 2020

Configuration management provides designers of automation systems with a framework to develop effective automation systems despite their inherent complexity. By managing the complexity of the system, and assisting in low-level decision-making, configuration management systems enable human designers, operators and system technicians to focus on high-level decision-making where their knowledge and experience are the most valuable. The development of flexible, modular small automation systems for the Advanced Recovery and Integrated Extraction System (ARIES) Pilot Line at Los Alamos National Laboratory, can serve as a case study for the development of a configuration management methodology. Furthermore, this case study can be used to identify potential design tools that can assist in the development of automation systems. An examination of a specific case, that of the Hot-side Electrodecontamination Chamber of the ARIES Pilot Line has been used to identify necessary research developments and demonstrate the utility of the configuration management process.
Understanding Voids in the Workspace of Serial Robot Manipulators
Authors: Abdel-Malek Karim , Yeh Harn-Jou , Othman Saib
Published: December 2020

Analytical methods for identifying the boundary to the workspace of mechanical manipulators and the boundary to voids in the workspace are presented. The determination of parametric equations of surface patches that envelop the workspace of serial manipulators was presented elsewhere and is extended in this paper to an analytical method for void identification. Because of the ability to identify closed-form surface patches that exist internal and external to the workspace, a mathematical formulation based on the concept of a normal acceleration function is introduced. Admissible motion in the normal direction to a point on a singular surface is delineated and characterized by definiteness properties of a quadratic form. An enclosure bound by surface patches that do not admit normal motion towards its internal is identified as a void. Several examples are treated using this formulation to illustrate the method.
Path Planning With Selective/Desriable Orientation in Finite Twist Mapping Space
Authors: Shah Paresh , Dai Jian S.
Published: December 2020

The paper proposes a new approach for path planning based upon the finite twist mapping spaces and discusses the selective and desirable orientation in the planning. In the FT mapping space, positions and orientations are presented in conjunction with configuration space with the dexterous and partial dexterous workspaces. The path planning can hence be made with a range of dexterity of a manipulator to meet a desirable orientation. The work also extends to redundant manipulators.
A Geometric Based Method for Distance-to-Contact Calculations in Two Dimensions
Authors: Wu C. , Mayne R. W.
Published: December 2020

This paper considers distance-to-contact (DTC) calculation strategies to improve computational efficiency in two dimensional motion planning. A basic DTC calculation approach is described which combines geometric concepts and iterative calculations in identifying the minimum distance between two separated objects of interest. The developed approach, termed the “Q-polygon” method, efficiently obtains the analytical minimum distance between two convex objects. The paper describes the development of the Q-polygon strategy and considers its performance in representative DTC calculations. The performance of the Q-polygon approach compares very favorably to a typical quadratic programming technique for basic DTC calculations and shows an impressive low sensitivity to increasing complexity of the considered objects.