bluuebunny/crossref_metadata_2025 huggingface dataset:
A Simulation-Based RBDO Method Using Probabilistic Re-Analysis and a Trust Region Approach
Authors: Kuczera Ramon C. , Mourelatos Zissimos P. , Nikolaidis Efstratios , Li Jing
Published: July 2010

A simulation-based, system reliability-based design optimization (RBDO) method is presented which can handle problems with multiple failure regions. The method uses a Probabilistic Re-Analysis (PRRA) approach in conjunction with a trust-region optimization approach. PRRA calculates very efficiently the system reliability of a design by performing a single Monte Carlo (MC) simulation. Although PRRA is based on MC simulation, it calculates “smooth” sensitivity derivatives, allowing therefore, the use of a gradient-based optimizer. The PRRA method is based on importance sampling. It provides accurate results, if the support (set of all values for which a function is non zero) of the sampling PDF contains the support of the joint PDF of the input random variables and, if the mass of the input joint PDF is not concentrated in a region where the sampling PDF is almost zero. A sequential, trust-region optimization approach satisfies these two requirements. The potential of the proposed method is demonstrated using the design of a vibration absorber, and the system RBDO of an internal combustion engine.
Designing a Modular Rapid Manufacturing Process
Authors: Stroble Jacquelyn K. , Liou Frank W.
Published: July 2010

Freeform Fabrication and additive fabrication technologies have been combined with subtractive processes to achieve a variety of fully integrated rapid manufacturing systems. The combination of separate fabrication techniques into one rapid manufacturing system results in unit manufacturing process integration, sometimes known as a hybrid system. However, the design methods or approaches required to construct these integrated systems are vaguely described or not mentioned at all. The final product from any integrated system is affected not only by the unit manufacturing processes themselves, but also by the extent the individual units are assimilated into an integrated process. A wide variety of integrated and hybrid manufacturing systems and current manufacturing design methodologies are described in this paper, along with their similarities and differences. Through our extensive review it was discovered that there are five key elements to a reliable integrated manufacturing system: process planning software, motion system, control system, unit manufacturing process, and finishing process. By studying the manner in which all other systems have been integrated, a table of successful integrated manufacturing system elements combinations has been created, documenting each of the key element choices, resulting in a variety of modular designs. A table of common obstacles encountered during manufacturing system integration has been compiled and presented in Section 4. This paper further discusses the importance of the five elements in manufacturing system integration, and how integrated systems is the way to move forward in the manufacturing domain. In the final Section, we describe our modular design experience to demonstrate how unit manufacturing process integration has increased productivity and the capabilities of a laser aided manufacturing process.
Assessing How Digital Design Tools Affect Learning of Engineering Design Concepts
Authors: Stroble Jacquelyn K. , Stone Robert B. , Watkins Steve E.
Published: July 2010

Engineering education has been evolving over the last few decades to include more engineering design courses in the curriculum or offer a new degree altogether that allows one to design a unique degree suited to his or her own interests and goals. These new engineering curricula produce engineers with strong backgrounds in fundamental engineering and design knowledge, which make them strong candidates for solving complex and multidisciplinary engineering problems. Many universities have embraced the need for multidisciplinary engineers and have developed interdisciplinary engineering design courses for many experience levels. Such courses build a foundation in engineering design through a unique series of lectures, real-world examples and projects, which utilize validated design tools and methodologies. This paper assesses the value of using design tools, web-based and downloadable, in undergraduate interdisciplinary design engineering courses. Six design tools are tested for their ability to increase the student’s knowledge of six design concepts. Also, the tools are evaluated for ease of use and if the different digital formats affect their educational impact. It was found that most students valued all the design tools and that the tools reinforced all but one design concept well. Quotes from the open-ended portion of the survey demonstrate the acceptance of the design tools and a general understanding of the importance of engineering design. The design tools, design concepts course goals, survey questions and survey results are discussed.
The Birth of Symbols in Design
Authors: Mukerjee Amitabha , Dabbeeru Madan Mohan
Published: July 2010

In the widespread endeavour to standardize a vocabulary for design, the semantics for the terms, especially at the detailed levels, are often defined based on the exigencies of the implementation. In human usage, each symbol has a wide range of associations, and any attempt at definition will miss many of these, resulting in brittleness. Human flexibility in symbol usage is possible because our symbols are learned from a vast experience of the world. Here we propose the very first steps towards a process by which CAD systems may acquire symbols is by learning usage patterns or image schemas grounded on experience. Subsequently, more abstract symbols may be derived based on these grounded symbols, which thereby retain the flexibility inherent in a learning system. In many design tasks, the “good designs” lie along regions that can be mapped to lower dimensional surfaces or manifolds, owing to latent interdependencies between the variables. These low-dimensional structures (sometimes called chunks) may constitute the intermediate step between the raw experience and the eventual symbol that arises after these patterns become stabilized through communication. In a multi-functional design scenario, we use a locally linear embedding (LLE) to discover these manifolds, which are compact descriptions for the space of “good designs”. We illustrate the approach with a simple 2-parameter latch-and-bolt design, and with a 8-parameter universal motor.
On an Adaptive Multi-Mask Overlay Strategy for Topology Optimization of Structures and Compliant Mechanisms
Authors: Jain Chandini , Saxena Anupam
Published: July 2010

The honeycomb based discretization shows promise in yielding checkerboard and point flexure free optimal solutions to various topology design problems. The mesh-free material mask overlay method further promises unadulterated “black and white” optimal solutions as opposed to schemes where material is interpolated between the “void” and “filled” states in a cell [26]. Here, we propose improvements in the material mask overlay method by judiciously choosing the number of masks during a sequence of sub-searches for the optimal solution. We use an alternative mutation based zero order search which allows the use of a small population of solutions and also maintains diversity between them. Thus, multiple solutions can be simultaneously obtained for non-convex topology optimization formulations. We solve two classical problems each on optimal stiff structures and compliant mechanisms to illustrate pathology free, “black and white” topology synthesis.
Modeling, Control and Simulation of a New Large Scale Cable-Driven Robot
Authors: Alikhani Alireza , Behzadipour Saeed , Ghahremani Farbod , Alasty Aria , Sadough Vanini S. Ali
Published: July 2010

In this paper, modeling and control of a new cable-driven robot is presented. In this mechanism, the cable arrangement eliminates the rotational motions leaving the moving platform with three translational motion. The mechanism has potentials for large scale manipulation and robotics in harsh environments. In this article kinematics and dynamics models for the proposed cable-driven architecture are derived. Additionally, Feedback linearization under input constraints is used for the control of the robot. The control algorithm ensures the cable tensions are positive while minimizing the sum of all the torques exerted by the actuators. Finally, the implementation of the proposed method is demonstrated through simulation.
Scheme Design and Optimal Selection for HEV Planetary Gear Coupling Mechanism
Authors: Zhu Futang , Chen Li , Yin Chengliang
Published: July 2010

More and more planetary gear mechanisms are being used in Hybrid Electric Vehicle (HEV) as multi-energy coupling mechanisms because of their compact structure, high transmission efficiency and strong load bearing capacity. In order to get all the planetary gear schemes that satisfy the requirements of topological characteristics and select the optimal scheme for Hybrid Electric Vehicle Planetary Gear Coupling Mechanism (HEV-PGCM) as the references for the following analysis and structure design. Firstly, a variety of HEV-PGCM schemes with required topological characteristics are designed by applying the Creative Design Method. Secondly, according to the design requirements of planetary gear transmission and HEV power coupling mechanism, combined with Matrix Theory, the scheme evaluating indicators and method for HEV-PGCM are presented and used for scheme analysis and optimal selection. The results indicate that this method is general for common use and it can provide reference schemes for the following structure parameter design and analysis of HEV-PGCM.
A Novel Tensed Mechanism for Simulation of Maneuvers in Wind Tunnels
Authors: Bruckmann Tobias , Mikelsons Lars , Brandt Thorsten , Schramm Dieter , Pott Andreas , Abdel-Maksoud Moustafa
Published: July 2010

Wind tunnels are a standard tool to evaluate the air flow properties of aerodynamical vehicles in model scale. This is widely used to optimize the design of aircrafts and aircraft components. Additionally, the hydrodynamic properties of marine components like ship hulls or propulsion systems can be predicted. It is desirable to guide the models along defined trajectories during the tests to vary the angle of attack. Parallel wire robots were successfully used to perform airplane maneuvers in wind tunnels due to their good aerodynamical and mechanical properties. Compared to aircraft design, marine models are very heavy (up to 500kg). Thus, the positioning system must be very stiff to avoid vibrations. Additionally, fast maneuvers require powerful drives. Nevertheless, the positioning system should not influence the air flow. In this contribution, a novel design is presented. Additionally, a new realtime capable force distribution calculation method for parallel tensed systems is presented.
Simultaneous Type and Dimensional Synthesis of Planar 1DOF Mechanisms Using Evolutionary Search and Convertible Agents
Authors: Oliva John C. , Goodman Erik D.
Published: July 2010

This paper introduces a novel approach to automated mechanism synthesis called “convertible agents”. The evolutionary computing technique has been developed specifically for the unique design challenges encountered when synthesizing a mechanism for both type and dimensionality. Several case studies are presented which demonstrate the approach’s effectiveness over earlier solution strategies. In these studies, six different planar single-degree-of-freedom mechanism types are considered: a four-bar mechanism, Stephenson’s six-bar-mechanisms (types I, II, and III), and Watt’s six-bar-mechanisms (types I and II). The method is readily scalable to account for any number of different mechanism types and complexities.
Pareto-Optimal Solutions Using Kinematic and Dynamic Functions for a Scho¨nflies Parallel Manipulator
Authors: Altuzarra Oscar , Pinto Charles , Sandru Bogdan , Amezua Enrique
Published: July 2010

The search of Pareto-optimal solutions for the optimal design of Low-Mobility Parallel Manipulators with Scho¨nflies motion is the subject of this paper. As a working example, a four-degree-of-freedom symmetric parallel manipulator for Scho¨nflies-motion generation is taken. In previous work, analytically found objective functions for the optimal design were used. As a consequence, some limitations were detected and new functions are required. First, a manipulator description is made, and kinematic and dynamic problems are solved. Next, an operational and dexterous workspace along with its volume is found making use of a discretization. Further, the variation of this volume with dimensional parameters is shown for purpose of optimal design. Similarly, the manipulator’s dexterity based on the Frobenius norm is found and weighted with the measure of dispersion. Then, upon a type of testing trajectory over this workspace, kinematic and dynamic results in the actuators are proposed as objective functions in multiobjective optimization.
Systematic Design Method for Large-Scale Manufacturing of Fabricated Polymers
Authors: Simpson Brian K. , Schaefer Dirk
Published: July 2010

There is a growing interest in the development of new design methods that will allow companies to adapt to a world that is becoming more competitive due to globalization and a rapidly changing global economic landscape. Several new techniques are being developed as a result of this interest that addresses the unique characteristics of product evolution. For example, Otto and Wood presented a new reverse engineering and redesign methodology that focuses on the process steps needed to understand and represent a current product with the combination of various techniques to address the different stages of the design process [1]. In this paper, we present a case study involving the use of augmentation tools such as affinity diagrams and quality function deployment’s (QDF) house of quality to augment the systematic design approach originally developed by Pahl and Beitz (P&B) [3] and apply it to an existing process and design issue. While presenting their approach, we apply our augmented approach to a laboratory-scaled fabrication process for the creation of adaptive polymer particles. We demonstrate that this augmented design approach could create a large-scale fabrication method that is low in cost, high in quality, and provides greater efficiency than the original method. According to our results, the process time was reduced by as much as 35.4% which would save thousands of dollars each year. In addition, the quality of the fabricated polymeric samples was improved significantly due to the use of advanced tools and simulation techniques. This augmented P&B method will provide an additional option for businesses and engineering designers to consider when faced with the challenges of sustaining designs and design processes.
Variation Feedback and 3D Visualization of Geometrical Inspection Data
Authors: Wandeba¨ck Fredrik , So¨derberg Rikard , Carlson Johan S. , Wahlborg Per-Johan , Lindkvist Lars , Ekstedt Fredrik
Published: July 2010

There is no type of manufacturing process that is not afflicted by variation. Activities intended to ensure the quality of a company’s geometry processes are usually referred to as geometry assurance activities. One clear industrial problem is to understand the relations between the products concept and the manufacturing process. Dimensional data is a very important source of experience of how a product’s geometry has worked in the interaction with the actual manufacturing system. Users therefore need good analysis and presentation tools of geometry outcomes to support both the product developers and production engineers in the analysis of the production output and its consequences. Today the dimensional data can be difficult to obtain or access, and is not necessarily presented in such a way as to provide the user with all necessary information. This paper presents how presentation and analysis tools of geometrical inspection data can be taken a step further. New functionality for feature based 3D visualization of inspection data has been developed which integrates the variation simulation platform and the inspection data database. The goal has been to create better tools for analysis of geometrical variation and increase the understanding of the sources of variation.
Automated Synthesis and Optimization of Gear Train Topologies
Authors: Swantner Albert , Campbell Matthew I.
Published: July 2010

A method for automating the design of simple and compound gear trains using graph grammars is described. The resulting computational tool removes the tedium for engineering designers searching through the immense number of possible gear choices and combinations by hand. The variables that are automatically optimized by the computational tool include the gear dimensions as well as the location of the gears in space. The gear trains are optimized using a three-step process. The first step is a tree-search based on a language of gear rules which represent all possible gear train configurations. The second step optimizes the discrete values such as number of teeth through an exhaustive search of a gear catalog. The final step is a gradient-based algorithm which optimizes the non-discrete variables such as angles and lengths in the positioning of the gears. The advantage of this method is that the graph grammar allows all possible simple and compound gear trains to be included in the search space while the method of optimization ensures the optimal candidate for a given problem is chosen with the tuned parameters.
Design and Development of a Free-Standing 4-DOF Infant Surgical Table
Authors: Siebler Scott R. , Nelson Carl A. , Hejkal Thomas
Published: July 2010

Retinopathy of prematurity is caused by abnormal blood vessel development in the retina of a premature infant. Current options for surgery tables used in laser treatment of this condition are limited. Full-size operating tables or table attachments are used but provide restricted patient manipulation and cause the surgeon to assume ergonomically undesirable positions. A stand-alone four-degree-of-freedom (4-DOF) infant surgical table was designed and is presented in this paper. The new table enables the surgeon to manipulate the patient while sitting in a comfortable position. The table platform can pitch left/right and fore/aft. The table platform can rotate 360° and translate vertically. Two linear actuators and a motor with ball screw provide the three degrees of freedom for table pitch and rotation through a spherical wrist-mechanism. A ball screw and motor achieve vertical movement of the table platform. The rigors of surgery and associated space constraints were accounted for in this design. The design consists of three subassemblies which can be disassembled for transport between operating theaters. A wide base is used to prevent the table from tipping. Biocompatible materials have been selected for all parts. Lastly, foot controls are used to keep the surgeon’s hands free.
An Application of Shape Grammars to Planning for CNC Machining
Authors: Ertelt Christoph , Shea Kristina
Published: July 2010

Planning for Computerized Numerical Control (CNC) fabrication requires generation of process plans for the fabrication of parts that can be executed on CNC enabled machine tools. To create such plans, a large amount of domain specific knowledge is required to map the desired geometry of a part to a manufacturing process, thus decomposing design information into a set of feasible machining operations. Approaches to automate this planning process still rely heavily on human capabilities, such as planning and reasoning about geometry in relation to machining capabilities. In this paper, the authors present a new, shape grammar-based approach for automatically creating fabrication plans for CNC machining from a given part geometry. To avoid the use of static feature sets and their pre-defined mappings to machining operations, the method encodes knowledge of fundamental machine capabilities. A method for generating a vocabulary of removal volume shapes based on the available tool set and machine tool motions is defined in combination with a basic rule set for shape removal covering tool motion, removal volume calculation and CNC code generation. The use of shape grammars as a formalism enables systematic formulation of hard and soft constraints on spatial relations between the volume to be removed and the removal volume shape for a machining operation. The method is validated using an example of machining a simple part on a milling machine. Overall, the approach and method presented is an enabler for the creation of an autonomous fabrication system and CNC machine tools that are able to reason about part geometry in relation to available capabilities and carry out on-line planning for CNC fabrication.
Engineering Work and Email: An Analysis of the Information Content of Email in a Major Systems Engineering Project
Authors: Wasiak James , Hicks Ben , Dong Andy , Newnes Linda
Published: July 2010

It is said, though not yet assessed, that a large amount of potentially valuable information may reside in engineering email correspondence. If this is the case, then due consideration must be given to the role of email for record keeping, Product Lifecycle Management and knowledge management. In order to examine this hypothesis, a methodology for assessing the information content of emails, and in particular those associated with engineering projects, has been created. The method is based on a textual analysis approach that is derived from cognitive design research and social psychology and further developed through iterative applications to industrial datasets. The paper describes the development of the approach and its classifications of what the subject of the email is, why the email has been sent, and how its content is expressed. The approach is validated using an email corpus from a software design project. The method is then applied to characterize the content of 800 emails from a large systems engineering project. The key findings from this major study are then presented and discussed with respect to the character of the content, including evidence of engineering work, the project lifecycle, and implications for information and knowledge management.
Stress Analysis of Spherical Gear Sets
Authors: Chao Li-Chi , Tsay Chung-Biau
Published: July 2010

The spherical gear is a new type of gear proposed by Mitome et al. [1]. Different from that of the conventional spur or helical gear sets, the spherical gear set can allow variable shaft angles and large axial misalignments without gear interference during the gear drive meshing [1, 2]. Geometrically, the spherical gear has two types of gear tooth profiles, the concave tooth and convex tooth. In practical transmission applications, the contact situation of a spherical gear set is very complex. To obtain a more realistic simulation result, the loaded tooth contact analysis (LTCA) has been performed by employing the finite element method (FEM). According to the derived mathematical model of spherical gear tooth surfaces, an automatic meshes generation program for three-dimensional spherical gears has been developed. Beside, tooth contact analysis (TCA) of spherical gears has been performed to simulate the contact points of the spherical gear set. Furthermore, the contact stress contours of spherical gear tooth surfaces and bending stress of tooth roots have been investigated by giving the design parameters, material properties, loadings and boundary conditions of spherical gears.
Synthesis Methods in Compliant Mechanisms: An Overview
Authors: Gallego Juan A. , Herder Just
Published: July 2010

Compliant mechanisms are rapidly gaining importance, yet their design remains challenging. A great variety of methods are being developed as it is reported in a growing stream of publications. However, so far no review of this body of literature is available. This paper provides a comprehensive and conceptual overview of the main notions behind the most relevant design methods for compliant mechanisms. Rigid-Body-Replacement methods including the Pseudo-Rigid-Body model and the FACT approach are covered, as well as Building Block approaches. In addition an introduction and explanation on Topology Optimization and Shape Optimization is provided, including their most common parameterizations and formulations. This work aims to serve as an introduction into compliant mechanism design methods and as a reference work for more experienced scholars and professionals. It is intended to be a starting point for the exploration of the literature, as well as a guide to specific papers about a particular design problem one may have. For this reason, the paper presents the methods in a wide perspective, emphasizing the conceptual ideas behind every method and refers to literature for details and advanced features.
Articulated MEMS Robot for Microfactory Applications
Authors: Murthy Rakesh , Popa Dan O.
Published: July 2010

A MEMS (Micro Electro Mechanical Systems) based four degree of freedom articulated microrobot is presented as an example of next generation miniaturized top down manipulators. The robot occupies 6mm3 in total volume with room for further down scaling. The operating work volume is 50μm × 50μm × 75μm with a 2P2R (Prismatic Prismatic Revolute Revolute) kinematic configuration — X, Y, Pitch and Yaw. The presented microrobot design rises above commonly encountered performance tradeoff’s of previous MEMS positioners such as range of motion vs. exerted force and range of motion vs. precision. It is constructed using a combination of hybrid microassembly and high aspect ratio micromachining. Structurally, the first version of the microrobot consists of Silicon 2 1/2 D parts and a 30μm diameter Cu wire. The robot joints and attachment of the end effector are accomplished by microassembly using compliant snap-fasteners, monolithic flexure joints, and epoxy glue. Actuation is carried out by two banks of in-plane electrothermal actuators, one coupled through an out of plane compliant socket, and the other one coupled remotely using a 30 μm diameter Cu wire. In this paper we present the microrobot kinematic design, and experimental identification of the robot Jacobian. Preliminary experimental characterization of the microrobot shows that it is repeatable to less than 0.5 μm along XY axes and 0.015 degrees along Pitch and Yaw DOFs. Finally, the robot was configured to carry an AFM tip and we demonstrate nano indentation sequences on a Parylene substrate.
Analytical and Experimental Frequency Response Analysis of Microcantilevers Subject to Tip-Sample Interaction
Authors: Delnavaz Aidin , Mahmoodi S. Nima , Jalili Nader , Zohoor Hassan
Published: July 2010

Improvement of microcantilever-based sensors and actuators chiefly depends on how comprehensively they are modeled and precisely formulated. Atomic Force Microscopy (AFM) is the most widespread application of microcantilever beam as a sensor, which is usually influenced by the tip-sample interaction force. For this, vibration of AFM microcantilever probe is analyzed in this paper, along with analytical, numerical and experimental investigation of the influence of the sample interaction force on the microcantilever vibration. Nonlinear integro-partial equation of microcantilever vibration subject to the tip-sample interaction is then derived and numerically simulated. Moreover, multiple time scales method is utilized to estimate the tip amplitude while it is vibrating near the sample. An experimental setup is developed using AFM in order to validate the theoretical and simulation results. Hysteresis, instability and amplitude drop can be identified in the experimental curves inside the particle attraction domain. These are likely related to the interaction force between the tip and sample as well as the presence of the water layer during the experiments. A fair agreement is observed between the theoretical analysis, numerical simulation and experimental findings which obviously demonstrates the effectiveness and applicability of the developed model.
A Compliant Straight-Line Shock Absorption Mechanism Using a Viscoelastic Pseudo-Rigid Body Model
Authors: Nelson Carl A.
Published: July 2010

A compliant suspension linkage based on the Peaucellier mechanism is presented. The suspension uses large-deflection viscoelastic beams to achieve straight-line motion and to provide energy dissipation. Kinematics and force analysis of the linkage are presented. In preparing to simulate the system dynamics, it was noticed that no adaptation of the pseudo-rigid body model for viscoelastic beams had been previously presented. Therefore, a new general approach for modeling viscoelastic, large-deflection beams in compliant mechanisms is described within the context of the pseudo-rigid-body model. This method is applied in simulation of the Peaucellier-based compliant suspension under a variety of input conditions.
Design and Numerical Analysis of Magnetic Microrotors for Micromixing
Authors: Khoshmanesh Khashayar , Kouzani Abbas Z. , Nahavandi Saeid , Kanwar Jagat R. , Baratchi Sara
Published: July 2010

This paper presents the design and simulation of a 3-D active micromixer. The mixer utilises two magnetic rotors to agitate the entering flows. Each rotor has three blades connected through a hub. The width of the blades increases linearly to enhance their impact on the surrounding flow. The performance of the mixer is studied within the rotation speeds of 150–275 rpm. Results indicate that the mixing efficiency increases linearly from 88.91% to 93.58% within the range of 150–250 rpm. Further increasing of rotor speed does not improve the mixing due to the resistance of corner flows. The proposed mixer can be applied as a component of lab-on-a-chip systems for medical applications.
An Experimental and Theoretical Investigation of Dynamic Pull-In in MEMS Devices Actuated Electrostatically
Authors: Alsaleem Fadi M. , Younis Mohammad I.
Published: July 2010

In this work, we investigate dynamic pull-in in MEMS devices actuated with a DC voltage superimposed to an AC harmonic voltage. We focus on the role of the AC frequency and amplitude in triggering instabilities. Dynamic pull-in is treated here in the context of a broader concept in nonlinear dynamics, which is the escape-from-potential-well phenomenon. The escape is defined where, for specific AC frequency and amplitude, the system exhibits the pull-in instability. We investigate dynamic pull-in experimentally in a polysilicon microcantilever beam, a cantilever and clamped-clamped microbeams made of gold, and a capacitive accelerometer. It is found experimentally that, despite the differences in their structures, the tested devices exhibit similar escape behavior near their fundamental natural frequency (primary resonance). A series of experiments are conducted using the capacitive accelerometer to study the effect of pressure (damping), excitation amplitude and frequency, resonance type (primary and subharmonic at twice the device’s natural frequency), and sweeping type (sweeping the AC amplitude or sweeping the AC frequency) on the escape zones. It is found that, except for the sweeping type, these factors have significant effect on shaping the escape zones. A nonlinear lumped-parameter model is used to capture the dynamics of the capacitive accelerometer. A shooting method is utilized to predict the theoretical zones of inevitable escape, where it is impossible for a resonator to oscillate in a stable state. An attempt has been made to relate the inevitable escape bands to the pull-in bands measured experimentally. We found that both pull-in bands and inevitable escape bands are correlated. However, we concluded that experimental testing is still needed to estimate accurately the instability bounds of each electrostatically actuated resonator.
Considerations for Motion Planning of a Robot With Two Actuated Spoke Wheels in the Two-Dimensional Sagittal Plane: Gaits and Transitions
Authors: Kimmel Shawn C. , Hong Dennis W.
Published: July 2010

IMPASS (Intelligent Mobility Platform with Active Spoke System) is a novel mobile robot which is driven by a pair of rimless spoke wheels which can alter the length of any given spoke in the hub. A highly mobile robot such as IMPASS could prove very valuable in applications where the terrain is complex and dangerous, but for this platform to be practical for real world use, motion control of the actuated rimless wheel must be automated. This work discusses considerations for motion planning concerning the transitions from step to step in the two-dimensional sagittal plane. Each step transition can be defined by a switching angle, which is the angle made between the back spoke and a reference axis. Presented is a review of the types of step transitions that are advantageous for ascending and descending obstacles, as well as traversing terrain with minor irregularities. These step transitions have been tested in simulation and on a physical prototype, the results of which will be discussed.
Design Workflow for Electronic Product With Safety Assessment Concept at the Early Stage
Authors: Huang Jingyuan , Wang Xiang
Published: July 2010

Today, the interdisciplinary design approach has been quickly adopted as a new trend in the modern product design process. Whereas, it is believed that manufacturers try to make shortcuts in order to reduce the time-to-market. Therefore, many inherent or uncertain safety parameters and factors are normally ignored in the early stage of the process until problems occur during the life cycles of products. This is very harmful to users. Enterprises may face liability claims and recalls of those products. In addition to the claims, additional time and cost are required to investigate the root cause of problems and to redesign the products and. Those problems mostly happen in some developing countries in which their product design and manufacturing process is still in a labor-intensive mode. Systematic and knowledge-based design approaches have not yet been popularly adopted. In order to have a better consideration, in terms of safety at the early stage of design process, the integration of practical experience of safety assessment concept and analysis methods into the traditional electronic product design process is the key proposed idea in this paper. A new design workflow with safety assessment concept at the early stage is generated, with a result of saving redesign cost and time.
Simulation of Double Flank Gear Rolling Testing
Authors: Liu Chia-Chang , Lin Kao- Hui
Published: July 2010

The double flank gear rolling testing is a method by which a master gear is rolled together, in tight mesh, with a testing gear. As the gears roll, slight variations of center distance are measured and recorded as an indicator of gear quality. The double flank gear rolling testing is easy and low coast, therefore, it is widely used in gear industry. In this study, the mathematical models of standard master gears and testing gears with various errors are carried out first according to the theory of gearing. Then, the process of double flank gear rolling testing is simulated by applying the concept of tooth contact analysis (TCA). Tooth contact types including surface-to-surface contact and tip-to-surface interference are considered, and three possible combinations of these two contact types occurring on each tooth flanks are discussed as well. The results of this study can provide the industry a significant process to establish the analysis and capacities for double flank testing.
A Novel Semi-Analytical Approach for Micro Beams Subjected to Electrostatic Loads and Residual Stress Gradients
Authors: Ou Kuang-Shun , Chen Kuo-Shen , Yang Tian-Shiang , Lee Sen-Yung
Published: July 2010

Beam structures are widely used in MEMS sensors and actuators. MEMS micro beams are usually curled due to residual stresses and the characteristics of micro beams subjected to both residual stress gradients and electrostatic forces must be investigated for providing accuracy information for designing sensors and actuators. In this work, a novel semi-analytical formulation to address the above needs is proposed. By assuming an admissible deformation shape and utilizing energy method to determine the coefficients of the shape functions, it is possible to find the pull-in characteristics of the curled cantilevers. Detail parametric studies are subsequently performed to quantify the influence of various geometry and processing parameters on the pull-in characteristics of those micro beams. The method and results presented in this work would be very useful for related micro sensors and actuator designs.
Trajectory Real-Time Obstacle Avoidance for Underactuated Unmanned Surface Vessels
Authors: Soltan Reza A. , Ashrafiuon Hashem , Muske Kenneth R.
Published: July 2010

A new method for obstacle avoidance of underactuated unmanned surface vessels is presented which combines trajectory planning with real-time tracking control. In this method, obstacles are approximated and enclosed by elliptic shapes which represent the stable limit cycle solution of a special class of ODEs (ordinary differential equation). The vessel trajectory at any moment is defined by the ODEs whose solution is the limit cycle defining the obstacle immediately on its path to the target. When no obstacle remains on the vessel’s path, the trajectory is defined by exponentially stable ODEs whose solution is the target trajectory. The planned trajectories are tracked by the vessel through a sliding mode control law which is robust to environmental disturbances and modeling uncertainties and can be computed in real time. One advantage of the method is that it allows for dynamic (moving and rotating) obstacles as well as a moving target. Another advantage is that only the current information about the obstacles and the target are required for real-time trajectory planning. Since the vessel current position is used as feedback to redefine the limit cycle trajectories, the method is also robust to large disturbance.
Hybrid General Heuristic Gradient Projection for Frame Optimization of Micro and Macro Applications
Authors: Hanafy Mohmmad M. A. , Metwalli Sayed M.
Published: July 2010

In this paper, a generalization is suggested for the Heuristic Gradient Projection method. The previous Heuristic Gradient Projection method (HGP) has been developed for 3D-frame design and optimization. It mainly employed bending stress relations in order to simplify the process of iterations for stress constrained optimization. The General Heuristic Gradient Projection (GHGP) is used in a more general form to satisfy the stress constraints. Another direct search method is hybridized to satisfy other constraints on deflection. Two examples are solved using the new method. The proposed method is compared with the Hybrid Fuzzy Heuristic technique (FHGP) when solving a MEMS resonator. Results showed that the proposed hybrid technique with (GHGP) converges to the optimum solutions faster by an 8%. The MEMS weight is also decreased by 23.7%. For a macro level, the GHGP improved the solution time by 33.3%. The hybrid technique with (GHGP) improved the stresses in the members of the optimum ten-member cantilever.
Torsional Sensitivity of the First Four Modes of an AFM Cantilever With a Sidewall Probe Using Analytical Method
Authors: Kahrobaiyan M. H. , Rahaeifard M. , Ahmadian M. T.
Published: July 2010

In this study, using analytical method, the torsional resonant frequency and torsional sensitivity of the first four modes of an AFM cantilever with sidewall probe including a horizontal cantilever and a vertical extension is analyzed and a closed form for torsional sensitivity of the probe is derived. In addition, the effect of relative parameters such as ratio of vertical extension length to horizontal cantilever length is investigated. According to this study, the results show that as contact stiffness increases, the resonant frequencies of all vibration modes increases until they reach constant values at very high values of contact stiffness. It is also can be found that low-order modes are more sensitive than high-order one. When contact stiffness increases, the torsional sensitivities of all vibration modes decrease and the graphs converge at very high values of contact stiffness. In addition, enhancement of ratio of vertical extension length to cantilever length decreases the resonant frequency of mode 1 for all values of the contact stiffness and decreases torsional sensitivity for low values of the contact stiffness. But for high values of contact stiffness, there is a peak for torsional sensitivity. Finally the result shows that increase of the tip mass, decreases the torsional sensitivity with a light slope.
Design of One Degree of Freedom Closed Loop Spatial Chains Using Non-Circular Gears
Authors: Harshe Mandar , Crane Carl , Dooner David B.
Published: July 2010

This paper presents the design of one degree-of-freedom spatial mechanisms that use non-circular gears to constrain the motion. In a spatial body-guidance problem, representing the motion by systems of polynomial equations restricts the number of end-effector positions and orientations (end-effector poses) that can be used as inputs for mechanism design. An approach has been developed that takes any number of desired poses as guide points and develops a mechanism that approximately attains the desired poses over the course of its motion. A problem with implementing this design strategy is the inherent difficulty in accounting for orientation and position errors. The approach described here addresses this problem by defining a new error functional, calculated in the joint space domain. As the mechanisms being dealt with are single degree-of-freedom closed chains, the starting position is a crucial decision in the design process. The method outlines the choice of the starting position and details how this error term can be used along with optimization techniques on either the mechanism parameters or the non-circular gears. A numerical example is presented.
Methods of Verification and Change Management for Quality Control of Engineering Artifacts
Authors: Van Wie Michael , Flechsig Scott
Published: July 2010

This work presents a method to incorporate the principles of verification and change management in order to address the quality control of engineering artifacts in early stage design. A refined definition of quality is presented and relates design quality to design iteration. A new model, the Decision Pathway Chart (DPC), is introduced to model decisions and iteration. A method and tool for incorporating this DPC model into a process for verifying and managing change through baselining is described and validated based on criteria for evaluating decision-based design methods. The contribution of this work is to introduce a practical technique for implementing quality control principles during design activities that typically lack such rigor toward quality assurance.
Self-Adaptive Compliant Grippers Capable of Pinch Preshaping
Authors: Birglen Lionel , Herbecq Francois
Published: July 2010

This paper discusses the possibility of designing self-adaptive fingers with compliant joints capable of pinch preshaping, i.e. seizing an object with only the distal phalanges. Following a discussion on how this can be achieved with non-compliant fingers, the authors presents a new technique that can be applied to compliant fingers. However, this method cannot be followed exactly but, if carefully analyzed, sufficiently approximated providing that certain compliant joints of the linkage have a significantly larger stiffness than the others. The examples of two designs, one two-phalanx finger and a similar design with three phalanges, are presented and discussed. Finally, the behavior of a gripper built using the method presented in the paper is verified using both a dynamic software package and a finite element analysis (FEA) software.
Four Dimensions of Design Similarity
Authors: Ranawat Arjun , Ho¨ltta¨-Otto Katja
Published: July 2010

To benefit from the value of a brand, a product family must have a coherent product family look. It is however not clear, what in the design contributes toward the coherence or similarity between the products. In this work, a product family identity is broken down into its basic design elements. The contribution of each of these basic design elements toward similarity is investigated. We present a framework of design elements in four dimensions. Examples of these design elements include color, texture, shape, and form. The contribution of these design elements toward the perceived product similarity is investigated. A two phased factorial analysis was performed. The first phase involved simplified shapes consisting of five design elements in the first two dimensions. In the second phase, a similar survey was repeated using images of real products. A survey of product pairs was given to a total of 52 participants. The results show that using the same shape, texture, color, and pattern has a significant effect on making a product pair seem similar to one another. The results will help a designer to design product families that have a coherent product family look but yet look clearly different from the competing brands.
Torsional Rigidity of a Cycloid Drive Considering Finite Bearing and Hertz Contact Stiffness
Authors: Kim Kyoung-hong , Lee Chun-se , Ahn Hyeong-Joon
Published: July 2010

This paper presents contact force and torsional rigidity analysis of a cycloid drive considering finite bearing and Hertz contact stiffness. Contacts between the disk and pin-rollers are simplified as linear spring elements, and the bearing is modeled as a rigid ring that has frictional contact to the disk and an elastic support. FE (finite element) analysis for contact force and Hertz theory calculation for contact stiffness are performed iteratively until the contact stiffness converges less than 1%. Contact force and pressure distributions under different contact and bearing stiffness are analyzed. In addition, effects of cycloid disk rotation are discussed. Finally, torsional rigidity of the cycloid drive is analyzed and compared with experimental result.
A Methodology for Quantifying the Perceived Environmental Friendliness of Vehicle Silhouettes in Engineering Design
Authors: Reid Tahira , Gonzalez Richard , Papalambros Panos
Published: July 2010

Methods from psychology and engineering are used to quantify subjective, or perceptual, design attributes of artifacts. A modeling framework of perceptual attributes suitable for inclusion in design optimization is presented. The framework includes stimuli development based on design of experiments, survey design, and statistical analysis of data. The proposed modeling method is demonstrated on a subjective attribute we call ‘perceived environmental friendliness’ using vehicle silhouettes as a case study.
An Information Technology Infrastructure for Internet-Enabled Remote and Portable Laboratories
Authors: Thames J. Lane , Hyder Andrew , Wellman Robert , Schaefer Dirk
Published: July 2010

With the proliferation of distributed and distance learning in higher education, there is a growing need for remote and portable laboratory design and deployment for the engineering, science, and technology education sectors. Amongst the current threads of research in this area, very little work has focused on solutions to the challenges, which are imposed by modern day information technology infrastructure, enterprise networks, and enterprise network security change management processes, that will be faced by large scale deployments of remote and portable labs. In this paper, the authors will discuss some of these challenges and will propose the use of the command and control communications architecture coupled with Web 2.0 as a solution to many of the deployment challenges.