bluuebunny/crossref_metadata_2025 huggingface dataset:
Validating a Tool for Predicting Problem-Specific Optimized Team Characteristics
Authors: McComb Christopher , Cagan Jonathan , Kotovsky Kenneth
Published: November 2017

The performance of a team is highly dependent on how the team is structured, how individuals in the team communicate with one another, and the properties exhibited by the problem being solved. It is generally assumed that teams are a superior approach in problem-solving and design. However, this work shows that for a configuration design problem of moderate size, the optimal approach for a homogenous team is in fact for members of the team to work independently, with the best solution from the individuals chosen at the end. Moreover, this work demonstrates that this surprising strategy can be predicted from knowledge of the problem’s properties through a computationally-derived set of response surfaces. First, a novel design problem is defined that requires solvers to create a system of internet-connected products to maintain the temperature within a home. Next, the characteristics of this new design problem are measured, and a computationally-derived response surface yields the untraditional prediction that teams should not interact while solving the problem. Finally, this prediction is tested and shown correct through a cognitive study. This work makes two contributions to the state of the art. First, it provides verification of a methodology that allows optimal team characteristics to be predicted based on knowledge of a design problem. Second, it demonstrates an additional problem instance for which interacting teams are inferior to nominal teams (adding to a growing literature to that effect).
Origins of Design Principles: The Case of Nuclear Reactor Design Projects
Authors: Verma Aditi
Published: November 2017

Through a cross-sectional study of reactor design projects, this work explores the origins of design principles. The analysis of in-depth, open ended interviews with reactor designers reveals that there are design principles of which practitioners are aware (self-aware principles), and those principles recurring across projects which designers implicitly use in their work (naive principles). This analysis suggests that the ability of practitioners to generate principles is a function of the development of the domain of design and of its particular technologies. Larger the menu of prior designs, greater is the ability of practitioners to generate principles on which to base future work. In closing, and based on the analysis of interviews with reactor designers, I propose a set of criteria for use by design researchers developing design principles for practitioners.
Kinematics and Discretization of Curved-Fold Mechanisms
Authors: Lang Robert J. , Nelson Todd , Magleby Spencer , Howell Larry
Published: November 2017

We present several new properties of curved-fold mechanisms, those with smoothly curved surfaces joined by sharp curved folds. After describing curved folds and various relationships among their geometric properties, we show that there is an important class, uniform folds, that is particularly well suited to low-degree-of-freedom mechanisms. There is a natural discretization algorithm for uniform curved folds; we present this algorithm and show discretized example mechanisms.
A Broadband Energy Harvester With Internal Resonance Induced by Two Resonators
Authors: Yang Wei , Towfighian Shahrzad
Published: November 2017

Nonlinear energy harvesting has a better performance than linear resonators, because realistic ambient vibrations are spread over a wide frequency spectrum. We present a broadband nonlinear energy harvester with internal resonance induced by two resonators. Each resonator contains a cantilever beam with a magnet tip, and one is partially covered by piezoelectric material. The perturbation method of multiple scales is used to solve coupled partial different equations by applying internal resonance of ratio 2:1. The shooting method validates the analytical solutions of the frequency response and output voltage numerically. Output voltage for different excitation levels and distances are investigated. Simulations show the design, by applying internal resonance and nonlinearity, increases the bandwidth of frequency response.
Third-Order Differential-Algebraic Equations for Improved Integration of Multibody Dynamics
Authors: Sommer H. J.
Published: November 2017

This paper introduces the concept of third-order differential-algebraic equations (DAE) for dynamics of constrained multibody systems. Third-order DAE provide jerk of components which can be integrated simultaneously with acceleration to provide improved simulation accuracy. A new Obreshkov predictor-corrector multistep integrator was developed to test this concept. Results from simulations of two planar mechanisms indicate that third-order DAE can reduce computation time by a factor of ten with equivalent accuracy compared to classical methods.
Modeling Length Effects of Braided Pneumatic Actuators
Authors: Hunt Alexander J. , Graber-Tilton Alexander , Quinn Roger D.
Published: November 2017

Braided pneumatic actuators (BPAs) are attractive for use in bio-robots because they offer many muscle-like properties, especially when compared to most other commercially available robotic actuators. Unfortunately, the same properties that make these actuators similar to muscles make them more difficult to control. One such actuator manufactured by Festo, the MXAM-10-AA, is frequently utilized in robotics because of its commercial availability, durability, and force capability. Although models for BPAs exist, the properties that make this actuator more durable also make its behavior less like other braided pneumatic actuators, especially for shorter actuator lengths. Length specific models that do exist for Festo fluidic muscles have numerous parameters that can only be found experimentally by taking hundreds to thousands of data points and performing a lengthy optimization process to fit parameter values for each actuator in the system. This lack of generalizability makes it difficult to build a new robot and begin testing new control systems without significant startup time and cost. The key contribution of this work is the development of a generalizable actuator model that accounts for the geometry and limitations of the actuator at shorter lengths. This empirical model relates internal pressure, strain, stretching or contracting state, and applied force on the MXAM-10-AA actuator. The model is scalable to different length actuators by measuring their resting length at zero pressure and their minimum contraction length at maximum air pressure, and can be used for feedforward length control. The model is evaluated on a robot leg with three joints and 6 actuators, each with different length. The developed controller, using the actuator model, controls the joints to within ± 3 degrees of the desired position for different desired torques only using internal actuator pressure feedback. We also demonstrate control speed by cycling a joint over 40 degrees of rotation at varying frequencies.
Research on Calculation of Unloaded Transmission Error of Planetary Gear Train Caused by Eccentricity
Authors: Zou Shuaidong , Wang Guangjian , Yu Li
Published: November 2017

In this paper, calculation of no-load transmission error (TE) of planetary gear train is studied. The theory computational model of the eccentric planetary gear train with single planet gear (SPG) under no-load conditions is constructed initially for acquiring the formulas of no-load transmission ratio error and unloaded transmission error (UTE) of internal and external gear pairs. Then computational formula of the UTE of planetary gear train with SPG caused by eccentricity is presented. Through simulation TE and the developed formula of UTE, the eccentricities and initial phasing are uncoupled by curve fitting. Simultaneously, formula of UTE of planet gear train with SPG is validated. At the same time, different groups of initial phasing are analyzed to acquire the relatively good initial phasing group. In addition, the UTE of planetary gear train with multiple planet gears (MPG) caused by eccentricity is developed.
Element Based Force Analysis of a Single Input-Multiple Output Linkage System
Authors: Sun Cong Zhu (John) , Xi Fengfeng (Jeff) , Moosavian Amin , Inman Daniel J.
Published: November 2017

Presented in this paper is a method for force analysis of a single-input multiple-output (SIMO) linkage array that is designed for curve morphing applications, such as morphing airfoils. Different from the existing force methods, this method is developed to determine the force of a single actuator at the front that is needed to resist the forces on each loop for the entire multiloop linkage system. The proposed method is based on a full force model of a single loop four-bar linkage. When this model is applied to a multiloop system, two force sources are considered for each loop, namely the external point force on the coupler and the internal transition torque from the proceeding loop. As a result, a recursive method is proposed to compute the force from the last loop through intermediate loops to the first loop. The force vector of the first loop represents the required force of the single actuator needed to counteract the forces experienced by all the coupler forces. A number of simulations are performed and compared with FEM results to prove its effectiveness.
Unrestricted Wind Farm Layout Design With Optimal Control Considerations
Authors: Deshmukh Anand P. , Allison James T.
Published: November 2017

Wind energy is a rapidly expanding source of renewable energy, but is highly intermittent. The performance of a wind farm, composed of a collection of wind turbines, depends not only on the placement of wind turbines in a farm, but also control actions taken by individual turbines. The wind turbine placement (layout) design problem involves adjusting turbine locations within a given area to improve a performance objective (such as maximizing annualized energy production). This layout problem has been addressed previously considering the effect of constraints such land configuration, installed capacity, and wake model choice on the performance of wind farms. All the studies, however, ignore the effects of the control system, which can have significant impact on performance. A well designed wind farm — without an optimal controller — will not achieve the full system level optimal performance, and vice-versa. In this article, we propose a novel layout co-design approach that includes optimal control considerations to exploit this synergy between farm layout and control. Layout case studies involving 8 and 12 turbines are presented. An annual energy production improvement of up to 17% is observed when accounting for coupling between control and layout design, when compared to layout-only optimization.
Energy Informatics and Fractional Calculus
Authors: Liu Kai , Zhang Xi , Chen YangQuan
Published: November 2017

Energy informatics (EI) is relatively a blossoming and dynamic research area especially in today’s green manufacturing world. Using renewable energy and clean technology are the keys to a revitalization of the world manufacturing and job creation. Green manufacturing, which reduces resource use, waste and emissions and saving the energy, has become the priority for the manufacturers. Therefore, EI has come into a desirable solution. The fractional calculus (FC) is a mighty tool which can characterize the complex properties of the natural and social phenomena. In this paper, we have provided an overview on the current EI by describing current research topics and methods and then pointed out an outlook of how this new field might be evolved with FC in the coming future.
Model-Free Control Approach of a Three-Tank System Using an Adaptive-Based Control
Authors: Madadi Elmira , Dong Yao , Söffker Dirk
Published: November 2017

For improving the dynamics of systems in the last decades model-based control design approaches are continuously developed. The task to design an accurate model is the most relevant and related task for control engineers, which is time consuming and difficult if in the case of complex nonlinear systems a complex modeling or identification problem arises. For this reason model-free control methods become attractive as alternative to avoid modeling. This contribution focuses on design methods of a model-free adaptive-based controller and modified model-free adaptive-based controller. Modified approach is based on the same adaptive model-free control algorithm performing tracking error optimization. Both approaches are designed for non-linear systems with uncertainties and in the presence of disturbances in order to assure suitable performance as well as robustness against unknown inputs. Using this approach, the controller requires neither the information about the systems dynamical structure nor the knowledge about systems physical behaviors. The task is solved using only the system outputs and inputs, which are measurable. The effectiveness of the proposed method is validated by experiments using a three-tank system.
Identifying Patent Precedents for Engineering Design: An Iterative Heuristic Method of Mining Text, Citation and Inventor Information
Authors: Song Binyang , Luo Jianxi
Published: November 2017

Engineering designers often investigate patents as design precedents to learn about relevant prior arts, seek design inspiration, or assess the novelty of their own new inventions. However, patent retrieval relevant to the design of a specific product or technology is often unstructured and unguided, and resultant patents do not accurately capture the prior knowledge base. This paper proposes an iterative and heuristic methodology to comprehensively search for patents as precedents for the design of a specific technology or product. The methodology integratively mines patent text, citation and inventor information to identify relevant patents; in particular, the search keyword set, citation network, and inventor set are expanded through heuristic learning from the patents identified in prior iterations. The method relaxes the requirement for search keywords while improving patent retrieval accuracy. We apply the method to the identification of self-propelled spherical rolling robot patents. Engineers can use this repeatable method to retrieve patent sets representing the design precedents of their specialized interests.
Object Reorientation and Creative Performance
Authors: Olteţeanu A.-M. , Shu L. H.
Published: November 2017

Functional fixedness refers to a cognitive bias that prevents people from using objects in new ways, and more abstractly, perceiving problems in new ways. Supporting people in overcoming functional fixedness could improve creative problem solving and capacities for creative design.

A study was conducted to detect whether a relationship exists between participants’ tendency to reorient objects presented as stimuli in an Alternative Uses Test and their creativity, also measured using the Wallach Kogan pattern meanings test. The Alternative Uses Test measures creativity as a function of identifying alternative uses for traditional objects. The Wallach Kogan pattern-meanings test detects the ability to see an abstract pattern as different possible objects or scenes. Also studied is whether Kruglanski’s Need for Closure scale, a psychological measure, can predict the ability to incorporate reorientation cues when identifying uses.

This study revealed highly significant, high correlations between reorientation and several creativity measures, and a correlation between reorientation and the predictability subscale of the Need for Closure scale. A qualitative exploration of participants’ responses reveals further metrics that may be relevant to assessing creativity in the Alternative Uses Test.
On the Usage of Berger’s Model for Electrostatically Actuated Circular Curved Micro Plates
Authors: Medina Lior , Gilat Rivka , Krylov Slava
Published: November 2017

Micro- and nanolectromechanical systems (MEMS/NEMS) incorporating two-dimensional structural elements such as plates attracted significant interest in recent years. In this work, we explore implementation of a model based on Berger’s approximation, which significantly simplifies the formulation of a curved plate and describes it by a single governing equation. The solution of this equation is based on the Galerkin decomposition with buckling modes of an initially flat plate used as the base functions. To track the unstable branches of the equilibrium curve, a continuous method based on the Riks algorithm is implemented. The validation of the models is conducted for two loading cases, “mechanical” deflection-independent load, and electrostatic displacement-dependent load. In the case of an initially flat plate, results provided by the reduced order (RO) Galerkin models were compared to results available in the literature. In the case of a curved plate undergoing “mechanical” loading, results of a direct finite elements (FE) analysis, as well as of a finite differences (FD) analysis, were used as a reference. We show that the DOF Berger RO model can be conveniently used for analysis of plates with small curvature, as it provides satisfactory accuracy. Further more, a single DOF model can be used for the development of a bistability criterion.
A Method for Slip-Stick Area Analysis of Contact Surface in Rotor Blades With Friction Damper
Authors: Xinnan Mao , Yanrong Wang , Hang Ye
Published: November 2017

High cycle fatigue damage caused by resonance can significantly affect the reliability and life of rotor blades in turbomachinery. Dry friction damper is widely used in vibration reduction design of joint components because of its excellent performance. To predict the vibration response of rotor blades with friction damper, it’s necessary to analyze the pressure distribution of contact area and determine the contact state of each point. Most researchers focused on the construction and improvement of friction models, and assumed that only the normal pressure distribution decides where slip and stick areas are, but the shear traction also play a role.

In this paper, a novel method is proposed to quantitatively conduct the slip-stick area analysis of contact surface by means of theoretical derivation and numerical simulation. Both the non-dimensional normal pressure and shear traction distribution are obtained for different contact conditions. It is found that both the normal pressure and shear traction of each point dominate its contact state. Moreover, the area at contact edges always begins slipping firstly, even if the normal pressure there is much larger than contact center. The developed method will also help to establish more accurate partial-slip model for various jointed structures with friction damping.
Equivalent Five-Bar Linkages for the Singularity Analysis of Two-DOF Seven-Bar Linkages
Authors: Wang Jun , Nie Liangyi , Zhao Daxing , Ren Jun , Wang Quan , Sun Jinfeng , Ting Kwun-Lon
Published: November 2017

Equivalent four-bar linkage has been proved to be a simple and general approach for the identification of the singularity (dead center position) of single-DOF complex planar linkages. Based on the concept of equivalent four-bar linkage, this paper proposes the concept of equivalent five-bar linkage and extend this concept to analyze the singularity (dead center position) of three different topologies of two-DOF seven-bar planar linkages for the first time. The five links chosen from the two-DOF seven-bar linkage compose one equivalent five-bar linkage. A singular position may happen when the three passive joints of one equivalent five-bar linkage become collinear. When the equivalent five-bar linkage is at the singular position, the whole two-DOF seven-bar planar linkage must be also at the position of singularity. The propose method offers another geometric insights for the singularity analysis of two-DOF seven-bar planar linkages and other multiple-DOF planar linkages.
A Guided Particle Swarm Optimizer for Distributed Operation of Electric Vehicle to Building Integration
Authors: Chen Yang , Hu Mengqi
Published: November 2017

Relevant research has demonstrated that more potential benefits can be achieved when energy and information are transacted and exchanged locally among different energy consumers. With increasing number of electric vehicles (EVs), various models and solution strategies have been developed for collaboration between building and EV charging station to achieve greater energy efficiency. However, most of the existing research employs centralized decision model which is time consuming for large scale problems and cannot protect private information for each participator. To bridge these research gaps, a guided particle swarm optimizer based distributed decision approach is proposed to study the energy transaction between building and EV charging station. In the proposed decision approach, the marginal price signal of transactive energy is collected to guide iterative direction of particle’s velocity and position which can maximally protect private information of building and EV charging station. A study case based on a commercial building and a nearby charging station in Chicago area is designed for illustration. The experimental results demonstrate that our proposed marginal price guided particle swarm optimizer is more stable and efficient comparing with canonical particle swarm optimizer and two state-of-the-art distributed decision algorithms.
On an Optimal Control Applied in Atomic Force Microscopy (AFM) Including Fractional-Order
Authors: Tusset Angelo M. , Balthazar Jose M. , Jose de Lima Jeferson , Rocha Rodrigo T. , Janzen Frederic C. , Yamaguchi Patricia S.
Published: November 2017

In this work, the nonlinear dynamics of an Atomic Force Microscope (AFM) operating in tapping mode is investigated, considering the influence of squeeze film damping in fractional-order. Its influence plays an important role because the dynamics of the AFM can be led to different responses, e.g., periodic and chaotic motions, specially the influence of the derivative order when in fractional-order. In a way to characterize the type of behavior, the 0–1 test was used once this is a good tool to characterize fractional-order differential systems. In addition, the linear feedback control technique for fractional-order systems is applied to control the chaotic behaviors. Therefore, the results showed a nonlinear behavior presented by the AFM system. In addition, the feedback control technique was efficient to control the chaotic motion of the micro cantilever beam of the AFM, whose results included variation of parameters of the fractional derivative of the squeeze film damping.
Uncertain Parameter Estimation Approaches for Increasing the Effectiveness of Command-Shaped Engine Restart Strategies
Authors: Wilbanks J. Justin , Leamy Michael J.
Published: November 2017

This paper develops recursive least-squares (RLS) and extended Kalman filtering (EKF) approaches for estimating uncertain engine friction (and other) parameters necessary for successful implementation of a two-scale command shaping (TSCS) engine restart strategy. The TSCS strategy has been developed for mitigating vibrations in conventional and hybrid electric vehicle (HEV) powertrains during internal combustion engine (ICE) restart. Implementing the TSCS strategy increases the drivability of a HEV by reducing noise, vibration, and harshness (NVH) issues associated with ICE restart during a powertrain mode transition. This is accomplished primarily, by modifying the electric machine (EM) torque profile with linear and time-varying components over multiple time scales. For full implementation, the TSCS strategy requires input parameters characterizing the ICE which may be a) difficult to quantify, and/or b) uncertain due to their dependence on engine operating temperature and other environmental considerations. RLS and EKF algorithms tailored to TSCS are presented herein for estimating these parameters. It is shown that both the RLS and EKF algorithms can be used to estimate the necessary ICE parameters and increase effectiveness of the TSCS strategy. The EKF algorithm, in particular, estimates uncertain ICE parameters with minimal measurement requirements, giving it an advantage over the presented RLS algorithm.
On Hurty/Craig-Bampton Substructuring With Interface Reduction on Contacting Surfaces
Authors: Kuether Robert J. , Coffin Peter B. , Brink Adam R.
Published: November 2017

Structural dynamics models with localized nonlinearities can be reduced using Hurty/Craig-Bampton component mode synthesis methods. The interior degrees-of-freedom of the linear subcomponents are reduced with a set of dynamic fixed-interface modes while the static constraint modes preserve the physical coordinates at which the nonlinear restoring forces are applied. For finite element models with a highly refined mesh at the boundary, a secondary modal analysis can be performed to reduce the interface down to a truncated set of local-level characteristic constraint modes. In this research, the cost savings and accuracy of the interface reduction technique are evaluated on a simple example problem involving two elastic blocks coming into contact.
Planar Linkage Synthesis for Mixed Motion, Path and Function Generation Using Poles and Rotation Angles
Authors: Zimmerman Ronald A.
Published: November 2017

The kinematic synthesis of planar linkage mechanisms has traditionally been broken into the categories of motion, path and function generation. Each of these categories of problems has been solved separately. Many problems in engineering practice require some combination of these problem types. For example, a problem requiring coupler points and/or poses in addition to specific input and/or output link angles that correspond to those positions. A limited amount of published work has addressed some specific underconstrained combinations of these problems. This paper presents a general graphical method for the synthesis of a four bar linkage to satisfy any combination of these exact synthesis problems that is not over constrained. The approach is to consider the constraints imposed by the target positions on the linkage through the poles and rotation angles. These pole and rotation angle constraints are necessary and sufficient conditions to meet the target positions. After the constraints are made, free choices which may remain can be explored by simply dragging a fixed pivot, a moving pivot or a pole in the plane. The designer can thus investigate the family of available solutions before making the selection of free choices to satisfy other criteria. The fully constrained combinations for a four bar linkage are given and sample problems are solved for several of them.
An Electrically Actuated Microbeam-Based MEMS Device: Experimental and Theoretical Investigation
Authors: Ruzziconi Laura , Jaber Nizar , Kosuru Lakshmoji , Bellaredj Mohammed L. , Lenci Stefano , Younis Mohammad I.
Published: November 2017

The present paper deals with the dynamic behavior of a microelectromechanical systems (MEMS). The device consists of a clamped-clamped microbeam electrostatically and electrodynamically actuated. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. In the first part of the paper an extensive experimental investigation is conducted. The microbeam is perfectly straight. The first three experimental natural frequencies are identified and the nonlinear dynamics are explored at increasing values of electrodynamic excitation. Several backward and forward frequency sweeps are acquired. The nonlinear behavior is highlighted. The experimental data show the coexistence of the nonresonant and the resonant branch, which perform a bending toward higher frequencies values before undergoing jump or pull-in dynamics. This kind of bending is not particularly common in MEMS. In the second part of the paper, a theoretical single degree-of-freedom model is derived. The unknown parameters are extracted and settled via parametric identification. A single mode reduced-order model is considered, which is obtained via the Galerkin technique. To enhance the computational efficiency, the contribution of the electric force term is computed in advance and stored in a table. Extensive numerical simulations are performed at increasing values of electrodynamic excitation. They are observed to properly predict all the main nonlinear features arising in the device response. This occurs not only at low values of electrodynamic excitation, but also at higher ones.
Towards a Universal Social Impact Metric for Engineered Products That Alleviate Poverty
Authors: Stevenson Phillip D. , Mattson Christopher A. , Bryden Kenneth M. , MacCarty Nordica A.
Published: November 2017

More than ever before, engineers are creating products for developing countries. One of the purposes of these products is to improve the consumer’s quality of life. Currently, there is no established method of measuring the social impact of these types of products. As a result, engineers have used their own metrics to assess their product’s impact, if at all. Some of the common metrics used include products sold and revenue, which measure the financial success of a product without recognizing the social successes or failures it might have. In this paper we introduce a potential metric, the Product Impact Metric (PIM), which quantifies the impact a product has on impoverished individuals — especially those living in developing countries. It measures social impact broadly in five dimensions: health, education, standard of living, employment quality, and security. The PIM is inspired by the Multidimensional Poverty Index (MPI) created by the United Nations Development Programme. The MPI measures how the depth of poverty within a nation changes year after year, and the PIM measures how an individual’s quality of life changes after being affected by an engineered product. The Product Impact Metric can be used to predict social impacts (using personas that represent real individuals) or measure social impacts (using specific data from products introduced into the market).
A Simple Starting Point for Designing for and/or Assessing the Social Impact of Products
Authors: Ottosson Hans , Hirschi Emma , Mattson Christopher A. , Dahlin Eric
Published: November 2017

In this paper we present a starting point for designing for and/or assessing the social impact of engineered products. The starting point is a set of tables comprising products, their general functional characteristics, and the accompanying social impacts. We have constructed these tables by first extracting a set of social impact categories from the literature, then 65 products were qualitatively reviewed to find their social impact. The resulting product impact tables can be used at either the beginning of the product development process to decide what social impact to design for and discover product functions that lead to it, or later to qualitatively assess the social impact of a product being designed and/or to assess the impact of an existing product.
Comparing Facets of Divergent Thinking in Engineering Freshmen and Upperclassmen
Authors: Bennetts Caleb , Cheeley Avery , Caldwell Benjamin W. , Green Matthew G.
Published: November 2017

This paper studies how engineering education might change divergent thinking skills. We hypothesized that people use a higher amount of divergent thinking when a task is unfamiliar. Our previous work developed an online survey to measure divergent ideation in two ways: with one ideation task, equally familiar to both novice and experienced designers, and a second ideation task, familiar only to experienced designers. We sorted ideas from 40 engineering upperclassmen and 40 freshmen into hierarchical categories and scored fluency, flexibility, and originality. The results did not confirm our hypothesis; rather, we found that originality scores were not significantly different between freshman and upperclassmen. Additionally, both groups produced their most-original ideas in the generally-familiar ideation task.

Limitations in our methods prevented meaningful conclusions about flexibility, and further study will be necessary to confirm our other conclusions. To better explore factors influencing divergent thinking, we will refine our methods for future work and retest the participants from the freshmen group in a longitudinal study.
CAD Platform Independent Software for Automatic Grading of Technical Drawings
Authors: Ingale Sanchit , Srinivasan Anirudh , Bairaktarova Diana
Published: November 2017

Spatial visualization is the ability of an individual to imagine an object mentally and understand its spatial orientation. There have been multiple works proving that spatial visualization skills can be improved with an appropriate training. Such training warrant a critical place in the undergraduate engineering curricula in many engineering schools as spatial skills are considered vital for students’ success in the technical and design fields [1–4]. Enhanced spatial skills help not only professionals in the engineering field but also everyone in the 21st century environment. Drawing sectional views requires mental manipulation and visual thinking. To enhance students spatial reasoning, one of the authors of this study, conducted a class in spatial visualization. The course-learning goal aimed at improving first-year engineering students’ spatial reasoning through instruction on freehand drawings of sectional view. During the semester, two teaching assistants had to grade more than 500 assignments that consisted of sectional views of mechanical objects. This was a tedious and a time consuming task. Motivated by this experience, this paper proposes a software aiming at automating grading of students’ sectional view drawings. The proposed software will also give live feedback to students while they are working on the drawings. This interactive tool aims to 1) improve the learning experience of first year students, with limited CAD knowledge, and 2) introduce a pedagogical tool that can enhance spatial visualization training.
Disturbance Observer-Based Sliding Mode Control of a Piezoelectric Nano-Manipulator
Authors: Zhang Yangming , Yan Peng
Published: November 2017

This paper is concerned with the ultra high precision tracking control problem of a class of hysteretic systems with both external disturbances and model uncertainties. By integrating a time rate function of the input into the classical Prandtl-Ishlinskii operators, a rate-dependent Prandtl-Ishlinskii model is introduced to compensate the rate-dependent hysteresis of such systems. Furthermore, the resulting inverse compensation error is considered, and a finite-time convergent disturbance observer-based sliding mode control methodology is proposed to improve both the tracking accuracy and transient performance. In this control methodology, a finite-time convergent disturbance observer is employed to estimate various disturbances for accurate eliminations, where the inverse compensation error is regarded as a bounded disturbance. Meanwhile, a novel sliding mode controller is designed to achieve the finite-time stability of the closed-loop system. In particular, it can be proved that both the sliding variable and disturbance estimated error can converge to zero in a finite time. Finally, the proposed control architecture is applied to a PZT (piezoelectric transducer) actuated servo stage, where good hysteresis suppression capability and excellent tracking performance are demonstrated in the experimental results.
Time-Optimal Gait Planning for Six-Parallel-Legged Robot With Bounded Acceleration and Velocity
Authors: Chen Zhijun , Gao Feng
Published: November 2017

Time-optimal gait planning for legged robots can be seldom found, except in the field of humanoid robots. This paper proposes a time-optimal gait planning method for a six-parallel-legged robot with bounded velocities and accelerations of the active joints. The optimization model is established for the case when the robot uses 3–3 gait to walk and the end-effectors move along the specified elliptical path. The feasible region is analyzed, based on which a numerical integration method is applied to find the optimal solution. The optimized trajectory is compared with the non-optimized one in detail. The results show that the period of the optimized trajectory is shorten by 21.5%.
A Thesaurus-Guided Text Analytics Technique for Capability-Based Classification of Manufacturing Suppliers
Authors: Sabbagh Ramin , Ameri Farhad
Published: November 2017

Capability analysis is a necessary step in the early stages of supply chain formation. Most existing approaches to manufacturing capability evaluation and analysis use structured and formal capability models as input. However, manufacturing suppliers often publish their capability data in an unstructured format. The unstructured capability data usually portrays a more realistic view of the services a supplier can offer. If parsed and analyzed properly, unstructured capability data can be used effectively for initial screening and characterization of manufacturing suppliers specially when dealing with a large pool of prospective suppliers. This work proposes a novel framework for capability-based supplier classification that relies on the unstructured capability narratives available on the suppliers’ websites. Naïve Bayes is used as the text classification technique. One of the innovative aspects of this work is incorporating a thesaurus-guided method for feature selection and tokenization of capability data. The thesaurus contains the informal vocabulary used in the contract machining industry for advertising manufacturing capabilities. An Entity Extractor Tool (EET) is developed for the generation of the concept vector model associated with each capability narrative. The proposed supplier classification framework is validated experimentally through forming two capability classes, namely, heavy component machining and difficult and complex machining, based on real capability data.
Development of Multi Joint Gripper That Achieves Transition From Pinching to Envelope Grasping With Simple Control
Authors: Tamamoto Takumi , Nomura Soichiro , Takeuchi Keita , Koganezawa Koichi
Published: November 2017

This study proposes a Multi Joint Gripper (MJG) that achieves envelope grasping for unknown shape objects with simple control. In our previous study we have developed the MJG having a number of multi joint fingers. Each finger has back drivability with Variable Stiffness Mechanism (VSM) for adjusting the stiffness of joints. The MJG succeeded envelope grasping of various shape objects with no sensory feedback. We have also showed the MJG is able to handle objects by pinching with the finger tips and to shift into an envelope grasping. However, in some tasks requiring transition from pinching to envelope grasping, it occasionally failed because of difference of mode setting between pinching and grasping. In this paper, we discuss the pinching motion and the transition from pinching to envelope grasping. The finger mechanism we have proposed is mainly composed of a serially connected Differential Gear System (DGS), and it is controlled by only two actuators. One for driving all of the joints simultaneously and the other for VSM of every joints all together. We propose a novel mechanism for transition from pinching to envelope grasping , which requires no change of mechanical mode setting of the DGS. The experiments revealed that the MJG successfully achieves transition from pinching to envelope grasping with very simple control.
Design of a 2D Haptic System With Passive Variable Stiffness Using Permanent Magnets for Upper-Limb Rehabilitation
Authors: Jujjavarapu Sri Sadhan , Memar Amirhossein H. , Esfahani Ehsan T.
Published: November 2017

This paper presents a design of variable stiffness actuation system based on on the force interactions caused by permanent magnets. The system is designed for rehabilitation of the upper limb with the goal to enhance rehabilitation in both clinical and home environments. The proposed active rehabilitation system is composed of a lightweight 6-axes robotic arm to move the patients hand in the desired trajectory. The interaction stiffness is controlled by the mechanism attached to the end-effector. For this purpose, repelling magnet pairs in linear antagonistic configuration are used to control the stiffness of the handle. Stiffness in the mechanism can be controlled via adjusting the distance between the magnets. A mathematical model is presented to analyze the range of adjustable variable stiffness for this mechanism.
Manufacturing Energy Consumption Estimation Using Machine Learning Approach
Authors: Song Ruoyu , Lu Yanglong , Telenko Cassandra , Wang Yan
Published: November 2017

Environmental impacts of manufacturing are often significant and influenced by part and process parameters. Energy consumption is one of the most critical factors for the overall environmental impact of manufacturing. To achieve energy reduction, one must estimate the manufacturing energy consumption throughout the design stage. This paper presents an efficient data-driven approach to utilize machine learning to estimate energy consumption of a manufacturing process from a CAD model. The approach enables quick cost estimation with limited knowledge about the exact process parameters. A case study of fused deposition modeling is used to illustrate the feasibility of this framework and test potential regression methods. Lasso and elastic net regressions were compared in this study. The potential application of this framework to other manufacturing processes is also discussed.
In-Plane Blade-Hub Dynamics of Horizontal-Axis Wind Turbine With Mistuned Blades
Authors: Sapmaz Ayse , Acar Gizem D. , Feeny Brian
Published: November 2017

Understanding vibration of the wind turbine blades is of fundamental importance. This paper regards the effect of blade mistuning on the coupled blade-hub dynamics. Unavoidably, at any stage of the wind turbine, the set of blades will not be precisely identical due to the inhomogeneous material, manufacturer tolerances, etc.

This paper is based on blade-hub dynamics of a horizontal-axis wind turbine with mistuned blade. The equations of motion are derived for the wind turbine blades and hub exposed to centrifugal effects and gravitational and cyclic aerodynamic forces. The equations are coupled. To decoupled them, the independent variable is changed from time to rotor angle. The resulting blade equations include parametric and direct excitation terms. The method of multiple scales is applied to examine response of the system. This analysis shows that superharmonic and primary resonances exist and are influenced by the mistuning. Resonance cases and the relations between response amplitude and frequency are studied.
Some New Results on the Kinematics of 3R Serial Robots Using Nested Determinants
Authors: Thomas Federico , Perez-Gracia M. Alba
Published: November 2017

It has been recently shown that the singularity locus of a 3R robot, and in particular its nodes and cusps, can be algebraically characterized in terms of nested determinants. This neat and structured formulation contrasts with the huge and often meaningless formulas generated using computer algebra systems. In this paper we explore further this kind of formulation. We present two new results which we think are of interest by themselves. First, it is shown how Chrystal’s method, used to obtain the resultant of two quadratic polynomials, can be formulated as nested determinants. Second, it is also shown how the coefficients of the harmonic conic of two given conics, can also be expressed in the same form. These results lead to new formulations for the inverse kinematics of 3R robots, their singularity loci, their nodes, and some of their high-order singularities.
Finding the Stiffnesses of Interface Contact Elements for the Computational Model of Steam Turbine Blading
Authors: Voldřich Josef , Lazar Jan , Polach Pavel , Morávka Štefan
Published: November 2017

A method is proposed for fitting the so-called contact stiffnesses (CSs) of interface elements for a nonlinear dynamic model (NDM) of a bladed disk with integral contact couplings. The method is based on comparison between frequencies of the resonant response of NDM and known natural frequencies in limiting linear cases. For this purpose, an effective approach for calculation of the resonant response NDM is presented allowing CSs to be picked individually. The method is demonstrated for the case of steam turbine bladed disk equipped with 48 inch blades.
Modified Jacobian-Torsor Based Error Modeling and Quantitative Sensitivity Analysis for Single Axis Assembly of Machine Tool
Authors: Du Zhengchun , Wu Jian , Yang Jianguo
Published: November 2017

The influence of component errors on the final error is a key aspect of error modeling of CNC machine tool. Nevertheless, the mechanism by which the errors in mechanical parts accumulate to result in the component errors and then impact the final error of CNC machine, has not been identified; the identification of this mechanism is highly relevant to precision design of CNC machine. In this study, error modeling based on the Jacobian-torsor theory is founded to determine the mechanism by which fundamental errors in mechanical parts influence the comprehensive error of single-axis assembly. Firstly, the constraints of small displacement torsors (SDTs) for typical features and the statistical solution are proposed to perfect the modified Jacobian-torsor model theoretically. Next, the modified Jacobian-torsor model is applied to the error modeling of a single-axis assembly in a three-axis machine center. Furthermore, the comprehensive errors of the single-axis assembly are evaluated by Monte Carlo simulation based on the synthesized error model. The accuracy and efficiency of the modified Jacobian-torsor model are verified through a comparison between the simulation results and the measured data from a batch of similar vertical machine centers. Based on the modified Jacobian-torsor model, the application of quantitative sensitivity analysis of single-axis assembly is investigated, along with an analysis of the analysis of key error sources to the synthetical error ranges of the single-axis assembly. This model is providing a comprehensive method for the better understanding of the key error source of the machine tool and has the potential to enable error allocation and precision improvement of the assembly and the whole machine tool in future.
Numerical Investigation of Modal Amplitude Saturation in Micromechanical Cantilever Beam Resonators
Authors: Zhang Tianyi , Jiang Zhuangde , Wei Xueyong
Published: November 2017

Micromechanical resonators have extensive applications but unavoidably exhibit nonlinearities that may degrade the devices’ performances. A good understanding of their nonlinear dynamics is essential to the design of resonant devices. In this paper, we numerically investigated the dynamics of a cantilever beam resonator working at a coupled extensional and flexural vibrational modes with a 2:1 internal resonance. An amplitude saturation behavior is observed in the cantilever beam resonator by controlling the external driving force. The flexural mode shows a complex nonlinear behavior changing from a softening effect to a hardening effect and the extensional mode shows nonlinear behavior due to the nonlinear mode coupling.