bluuebunny/crossref_metadata_2025 huggingface dataset:
sFEA: A Lightweight, Scalable, and Secure Finite Element Analysis Technique
Authors: Chaduvula Siva C. , Atallah Mikhail J. , Panchal Jitesh H.
Published: November 2018

Designers need a way to overcome information related risks, including information leakage and misuse from their own collaborators during a collaborative product realization process. Existing cryptographic techniques aimed at overcoming these information related risks are computationally expensive and slow even for moderate problem sizes, and legal approaches (e.g., the use of non-disclosure agreements) are not effective. The computational practicality problem is particularly pronounced for simulation computations like finite element analysis (FEA), that involve both a geometric partitioning (meshing) and computations of cubic time complexity. In this paper, we propose a technological approach that enables designers to perform simulations, such as FEA computations, without the need for revealing their information to anyone, including their design collaborators. We demonstrate our approach using secure finite element analysis (sFEA) which enables designers to perform FEA without having to reveal structural/material information to their counterparts even though the computed answer depends on all the collaborators’ confidential information. We build sFEA using computationally efficient protocols implementing a secure co-design framework. One of our findings is that the most natural implementations of sFEA, using existing protocols, suffer from limited scalability. To overcome these limitations, we propose strategies that help improve the scalability of sFEA. We document and discuss the experiments we conducted to determine the computational overhead imposed by sFEA. The results indicate that the computational burden imposed by sFEA makes it challenging for large-scale FEA — our scheme significantly increases the problem sizes that can be handled when compared to implementations using previous algorithms and protocols, but large enough problem sizes will swamp our scheme as well (in some sense this is unavoidable because of the cubic nature of the FEA time complexity). This work is another step towards opening up new avenues for improving the way information is exchanged in collaborative simulation computations such as FEA.
A New Design of Main Cylinder Electric Booster for Brake-by-Wire System
Authors: Shah Danish Ali , Yu Liangyao , Liu Xiaohui , Zheng Sheng
Published: November 2018

BBW (Brake by Wire) system improved day by day, as safety control of transport is one of the most pressing issues. A new EHB (electric hydraulic brake) booster has been proposed in this paper to develop cars in a way that it can reduce a possibility of accidents and minimizing their consequences. EHB with main cylinder electric booster is a typical BBW system. As no vacuum used to drive the EHB system, it is the best choice for the modern transportation technology. The effect of the brake is comfortable because of the motor, which is used to assist in braking and it makes braking softer. Also in case of any fault, emergency braking is always available which is fully manual and without the assistance of any motor. After the Analysis of many EHB booster designs, in this paper, a locking and unlocking hook system is introduced to control the braking system. It is a first approach that is simple and cost-effective.

This brake system is an excellent choice because it is very safe, calculated, and serviceable in complete electrical vehicles. We used gear transmission system to achieve the required braking force with a little amount of torque. We also used SOLIDWORKS to design the model of the EHB booster and test dynamics. Introduced a mathematical model to change motor torque to linear force by using a ball screw mechanism. We verified it with MATLAB/SIMULINK simulation and Amesim model simulation. Reaction force, due to the fluid present in the main cylinder, was taken into account and a closed loop MATLAB/SIMULINK model was utilized to check kinematics of the designed booster.
Research on Performances of a Displacement Controllable Active Suspension
Authors: Zhao Zhen , Xu Lin , Liu Beibei , Abdelkareem Mohamed A. A. , Zou Junyi , Yu Jiaxing
Published: November 2018

The suspension is one of the most important systems in a vehicle, which can decrease the vehicle body vibration and maintain good ride performance and driving stability. As for strikingly rugged roads like off-road conditions, the traditional active suspension can hardly balance the contradiction between the wheel adhesion and the vertical accelerated speed of the body. To accelerate to a higher speed while ensuring the ride performance at the same time, high-quality suspension system must be created and applied.

As we all know, the active suspension can improve the driving stability and ride performance dramatically. In order to achieve the controllable adjustment of shock absorber damping and vehicle height, and realize the optimization of vehicle suspension performance, a new kind of active suspension which includes magnetorheological damper and servo electric cylinder is proposed. Then, the mathematical model of the proposed active suspension based on “Servo Electric Cylinder-Spring-Magnetorheological damper” is established after being simplified. Finally, the dynamic performances of the passive and active suspension in different modes are simulated by MATLAB based on its mathematical model and dynamic characteristic functions. The results indicate that the proposed active suspension, compared with the passive, can achieve the controlled adjustment of shock absorber damping and vehicle height, and ensure the ride performance.
Design and Analysis of a Cable-Driven Deployable Cylindrical Mechanism
Authors: Xiao Hang , Lu Shengnan , Ding Xilun
Published: November 2018

This paper presents the design of a deployable cylindrical mechanism which is driven by cable. The deployable mechanism can be deployed to approximate a cylindrical surface and be folded into a compact bundle. Construction of the cylindrical surfaces with Bennett linkages is introduced. Geometric shape of the connecting bars and structure of the joints are designed for compact bundle-folding configuration and avoiding the interference. Position kinematics of the mechanism is solved. Cable system is designed to drive the mechanism to deploy. A direction-changeable mechanism used for cable pulleys is proposed and the optimal design parameters are obtained. A ground experimental prototype is fabricated to validate the proposed design and to show the feasibility of the designed mechanism.
A Machine Learning Approach to Kinematic Synthesis of Defect-Free Planar Four-Bar Linkages
Authors: Deshpande Shrinath , Purwar Anurag
Published: November 2018

The past forty years of research in mechanism synthesis has witnessed an unprecedented volume of work in formulating and solving planar four-bar linkage synthesis problems. However, finding practical and useful mechanisms for the motion synthesis problem has proven to be elusive, as a large majority of mechanisms turn out to be defective with respect to their assembly modes. Most methods formulate the problem as a discrete precision position problem, which inherently ignores the continuity information in the input, resulting in linkages with branch-, circuit- and order-defects. In this paper, we bring together diverse fields of pattern recognition, machine learning, artificial neural network, and computational kinematics to present a novel approach that solves this problem both efficiently and effectively. At the heart of this approach lies an objective function that compares the motion as a whole thereby capturing designer’s intent. In contrast to widely used structural error or loop-closure equation based error functions which convolute the optimization by considering shape, size, position, and orientation simultaneously, this objective function computes motion difference in a form, which is invariant to similarity transformations. We employ auto-encoder neural networks to create a compact and clustered database of invariant motions of known linkages. The query is raised in the database for nearest neighbors, which are either solutions or good initial conditions for fast local optimization techniques. In spite of highly non-linear parameters space, our approach discovers a wide pool of defect-free solutions very quickly. We show that by employing proven machine learning techniques, this work could have far-reaching consequences to creating a multitude of useful and creative conceptual design solutions for mechanism synthesis problems, which go beyond planar four-bar linkages.
Design Heuristics: Analysis and Synthesis From Jet Propulsion Laboratory’s Architecture Team
Authors: Fillingim Kenton B. , Nwaeri Richard Ossie , Borja Felipe , Fu Katherine , Paredis Christiaan J. J.
Published: November 2018

This study offers insight into the processes of expert designers at the Jet Propulsion Laboratory (JPL) and how they make use of heuristics in the design process. A methodology for the extraction, classification, and characterization of heuristics is presented. Ten expert participants were interviewed to identify design heuristics used during early stage space mission design at JPL. In total, 101 heuristics were obtained, classified, and characterized. Through the use of postinterview surveys, participants characterized heuristics based on attributes including source/origin, applicability based on concept maturity, frequency of use, reliability, and tendency to evolve. These findings are presented, and statistically analyzed to show correlations between the participant perceptions of frequency of use, reliability, and evolution of a heuristic. Survey results and analysis aim to identify valid attributes for assessing the applicability and value of multiple heuristics for design practice in early space mission formulation.
Investigation of Impact Hammering Task of Musical Saw With a Humanoid Robot for Industrial Automation
Authors: Fuke Yusuke , Hirogaki Toshiki , Aoyama Eiichi , Mishima Akira
Published: November 2018

This study aimed to automate the hammering action and dual arm coordination of a humanoid robot using percussion instruments such as musical saw. In this report, we examined the hammering motion of the robot by using its elastic stiffness, the vibration reduction method of the hitting tool caused by the movement of the robot arm, and dual arm cooperative motion based on hammering sound feedback. The experimental results show that the humanoid robot can play the musical saw without making an S-shaped curve, as performed by humans. By considering these nonlinearities through the mathematical expression of the relationship among frequency, deflection, length of beam, and fulcrum deviation, an arbitrary scale can be generated in the saw. Based on the hammering task and acoustic recognition system, we developed an impact sound feedback system. It was possible to converge to the target frequency of the musical saw through the hammering sound feedback operation.
Comparing the Effects of Design Interventions on the Quality of Design Concepts As a Reflection of Ideation Flexibility
Authors: Henderson Daniel , Jablokow Kathryn , Daly Shanna , McKilligan Seda , Silk Eli
Published: November 2018

Various interventions (i.e., methods and tools that guide design work) have been developed to support successful idea generation in a design process. Our previous research explored the impacts of three such design interventions: cognitive-style based teaming, problem framing, and design heuristics. In this work, we looked across these interventions to compare their effects on students’ design ideas. In particular, 966 design ideas collected from 152 undergraduate students in engineering and industrial design from two Midwestern universities were analyzed to investigate their quality with and without each design intervention. Statistically significant differences were observed for the teaming and problem framing interventions. This study has implications for design educators in how design interventions might be used to affect students’ design solutions.
Numerical Computation of the Discrete 2D Fourier Transform in Polar Coordinates
Authors: Yao Xueyang , Baddour Natalie
Published: November 2018

The discrete Fourier transform in Cartesian coordinates has proven to be invaluable in many disciplines. However, in application such as photoacoustics and tomography, a discrete 2D-Fourier transform in polar coordinates is needed. In this paper, a discrete 2D-Fourier transform in polar coordinates is presented. It is shown that numerical implementation is best achieved by interpreting the transform as a 1D-discrete Fourier transform (DFT), a 1D-discrete Hankel transform (DHT) and a 1D-discrete inverse transform (IDFT) in sequence. The transform is tested by numerical simulations with respect to accuracy and precision for computation of the continuous 2D transform at specific discrete points. It was found that both the forward and inverse transform showed good accuracy to approximate the continuous Fourier transform. Moreover, good precision results were obtained, which indicate that the proposed transform itself does not add much error.
Experimental Setup to Characterize Shift Time for High Performance Hybrid Transmissions
Authors: Dorsch Daniel S. , Carrus Justin , Xu Zongying , Xu Derrick , Winter Amos G. , Wallach Matthew , Dokras Nupur , Marquart Timothy
Published: November 2018

Hybrid vehicles are increasingly common due to fuel efficiency regulations in place worldwide. High performance hybrids have typically been designed with a focus on improving performance, rather than the combination of both performance and efficiency. In order to improve efficiency of high performance cars, new hybrid architectures are necessary. When incorporating an electric motor, careful focus on operational modes allows for removal of certain elements, such as the reverse gear. Additionally, installing an electric motor directly coupled to the transmission without a clutch gives performance benefits, but requires detailed control of motor speed and novel methodology for shifting. In this paper, the design of an experimental setup for the electric drive in a high performance car hybrid transmission is presented. This architecture allows for characterization of synchronizer behavior during two different shifting methodologies. The first methodology is synchronizing a large rotational inertia with a small shaft speed difference (this differs from a gear shift in a traditional transmission with a large speed difference but small inertia). This situation is encountered when coupling an electric motor to the drivetrain, as the inertia of the electric motor is relatively large compared to a transmission layshaft, but the speed difference is small. The second is testing shifting of a synchronizer where dog tooth engagement happens immediately, with no friction cone to match the speed. This type of shifting is possible with precise electric motor speed control, sensing of the dog tooth position, and fast actuation. This methodology eliminates the need for a friction cone in the synchronizers, while maintaining fast gearshifts for performance driving. Our experimental setup for the electric drive in a hybrid transmission will be used to characterize synchronizer performance with these new shifting methodologies. The insights gained from this setup will aid in designing advanced hybrid architectures.
A Voxel-Based Design Approach for Creating Functionally Graded Structures via Material Extrusion Additive Manufacturing
Authors: Spillane Daniel R. , Meisel Nicholas A.
Published: November 2018

Functionally graded materials (FGMs) are heterogeneous materials engineered to vary material composition across the volume of an object. Controlled mixture and deposition of each material through a manufactured part can ultimately allow for specific material properties defined in different regions of a structure. While such structures are traditionally difficult to manufacture, additive manufacturing processes, such as directed energy deposition, material jetting, and material extrusion, have recently increased the manufacturability of FGMs. However, the existing digital design workflow lacks the ability to accurately mix and assign multiple materials to a given volume, especially in the case of toolpath dependent deposition processes like filament-based material extrusion. In this paper, we will address this limitation by using a voxel-based representation approach, where material values are assigned across a pixel grid on each geometry slice before converting to toolpath information for manufacturing. This approach allows for creation of structures with increased material complexity decoupled from the external geometry of the design space, an approach not yet demonstrated in the existing literature. By using a dual-feed, single melt-pool extrusion nozzle system, this research demonstrates the ability to accurately recreate mathematically derived gradients while establishing a digital workflow capable of integrating with the material extrusion AM process.
Improved Alignment Estimation for Autonomous Docking of Mobile Robots
Authors: Sohal Shubhdildeep S. , Saab Wael , Ben-Tzvi Pinhas
Published: November 2018

This paper presents the methodology for an improved visual tracking, intended for the autonomous control of mobile robots. We propose the cumulated use of the image processing method and positioning sensors for an improved visual tracking. The method primarily uses detection, tracking, and recognition techniques to locate the targets. The use of such methods will enable the robot to monitor the real-time continuous changes in the orientation and the alignment with respect to the target module. The proposed methodology is implemented on a subsisting genderless coupling mechanism which is integrated into a multi-directional hybrid locomotion module to test the alignment accuracy in an autonomous docking procedure. The long-term objective is to demonstrate the autonomous docking and self-reconfiguration of multiple mobile robots.
A Deep Adversarial Learning Methodology for Designing Microstructural Material Systems
Authors: Li Xiaolin , Yang Zijiang , Brinson L. Catherine , Choudhary Alok , Agrawal Ankit , Chen Wei
Published: November 2018

In Computational Materials Design (CMD), it is well recognized that identifying key microstructure characteristics is crucial for determining material design variables. However, existing microstructure characterization and reconstruction (MCR) techniques have limitations to be applied for materials design. Some MCR approaches are not applicable for material microstructural design because no parameters are available to serve as design variables, while others introduce significant information loss in either microstructure representation and/or dimensionality reduction. In this work, we present a deep adversarial learning methodology that overcomes the limitations of existing MCR techniques. In the proposed methodology, generative adversarial networks (GAN) are trained to learn the mapping between latent variables and microstructures. Thereafter, the low-dimensional latent variables serve as design variables, and a Bayesian optimization framework is applied to obtain microstructures with desired material property. Due to the special design of the network architecture, the proposed methodology is able to identify the latent (design) variables with desired dimensionality, as well as capturing complex material microstructural characteristics. The validity of the proposed methodology is tested numerically on a synthetic microstructure dataset and its effectiveness for materials design is evaluated through a case study of optimizing optical performance for energy absorption. Additional features, such as scalability and transferability, are also demonstrated in this work. In essence, the proposed methodology provides an end-to-end solution for microstructural design, in which GAN reduces information loss and preserves more microstructural characteristics, and the GP-Hedge optimization improves the efficiency of design exploration.
Design and Implementation of an Exoskeleton Glove for Infant Medical Rehabilitation
Authors: Refour Eric , Sebastian Bijo , Ben-Tzvi Pinhas
Published: November 2018

This paper describes the design and implementation of an exoskeleton glove for infants of ages ranging from 12 months to 3 years. The glove is capable of assisting the patient in achieving a pincer grasp in active and passive modes of operation. It can record information about the hand movement, forces exerted by the fingers on the exoskeleton frame, and provide vibration stimuli to the finger tips. The data recorded by the glove can be used in early diagnosis of cerebral palsy among high risk infants. It can also be used as a standalone device for rehabilitation purposes. The hardware, software architecture and experimental validation of the system are outlined in this paper.
Production Planning for Mass Customization in Additive Manufacturing: Build Orientation Determination, 2D Packing and Scheduling
Authors: Oh Yosep , Zhou Chi , Behdad Sara
Published: November 2018

The efficient production planning of Additively Manufactured (AM) parts is a key point for industry-scale adoption of AM. This study develops an AM-based production plan for the case of manufacturing a significant number of parts with different shapes and sizes by multiple machines with the ultimate purpose of reducing the cycle time. The proposed AM-based production planning includes three main steps: (1) determination of build orientation; (2) 2D packing of parts within the limited workspace of AM machines; and (3) scheduling parts on multiple AM machines. For making decision about build orientation, two main policies are considered: (1) laying policy in which the focus is on reducing the height of parts; and (2) standing policy which aims at minimizing the projection area on the tray to reduce the number of jobs. A heuristic algorithm is suggested to solve 2D packing and scheduling problems. A numerical example is conducted to identify which policy is more preferred in terms of cycle time. As a result, the standing policy is more preferred than the laying policy as the number of parts increases. In the case of testing 3,000 parts, the cycle time of standing policy is about 6% shorter than laying policy.
Data Driven Modeling and Optimization for Energy Efficiency in Additive Manufacturing Process With Geometric Accuracy Consideration
Authors: Ma Junfeng , Tian Wenmeng , Alizadeh Morteza
Published: November 2018

Despite of its tremendous merits in producing parts with complex geometry and functionally graded materials, additive manufacturing (AM) is inherently an energy expensive process. Prior studies have shown that process parameters, such as printing resolution, printing speed, and printing temperature, are correlated to energy consumption per part. Moreover, part geometric accuracy is another major focus in AM research, and extensive studies have shown that the geometric accuracy of final parts is highly dependent on those process parameters as well. Though both energy consumption and part geometric accuracy heavily depend on the process parameters in AM processes, jointly considering the dual outputs in AM process is not fully investigated. The proposed study aims to obtain a quantitative understanding of the impact of these process parameters on AM energy consumption given part quality requirements, such as geometric accuracy. The study utilizes a MakerGear M2 fused deposition modeling (FDM) 3D printer to complete the designed experiments. By implementing experimental design and statistical regression analysis technologies, the study quantifies the correlation between AM process parameters and energy consumption as well as the final geometric accuracy measure. An optimization framework is proposed to minimize the energy consumption per part. The Kuhn-Tucker non-linear optimization algorithm is used to identify the optimal process parameters. This study is of significance to AM energy consumption in terms of jointly considering energy consumption and final part geometric accuracy in the optimization framework.
Understanding the Role of Additive Manufacturing Knowledge in Stimulating Design Innovation for Novice Designers
Authors: Yang Sheng , Page Thomas , Zhao Yaoyao Fiona
Published: November 2018

Additive manufacturing (AM) is recognized as a disruptive technology that offers significant potentials for innovative design. Prior experimental studies have revealed that novice designers provided with AM knowledge (AMK) resources can generate a higher quantity and quality of solutions in contrast with the control groups. However, these studies have adopted general evaluation metrics that fall short in correlating AMK with radical or architectural innovation. This deficiency directly affects how AMK should be captured, modeled, and delivered so that novel opportunities may be more efficiently utilized in the ideation stage. To refine the understanding of AMK’s role in stimulating design innovation, an experimental study is conducted with two design projects: (a) a mixer design project, and (b) a hairdryer redesign project. The former of which aims to discover whether AMK inspiration increases the quantity and novelty of working principles (i.e. radical innovation), while the latter examines the influence of AMK on layout and feature novelty (i.e. architectural innovation). The experimental study indicates that AMK does have a positive influence on architectural innovation, but the effects on radical innovation are very limited if the provided AMK is functionally irrelevant to the design problems. Two strategies are proposed to aid the ideation process in maximizing the possibility of identifying AM potentials which facilitate radical innovation. The limitations of this study and future research plans are also discussed.
Reducing Evaluation Cost for Circuit Synthesis Using Active Learning
Authors: Guo Tinghao , Herber Daniel R. , Allison James T.
Published: November 2018

In this article, an active learning strategy is introduced for reducing evaluation cost associated with system architecture design problems and is demonstrated using a circuit synthesis problem. While established circuit synthesis methods, such as efficient enumeration strategies and genetic algorithms (GAs), are available, evaluation of candidate architectures often requires computationally-expensive simulations, limiting the scale of solvable problems. Strategies are needed to explore architecture design spaces more efficiently, reducing the number of evaluations required to obtain good solutions. Active learning is a semi-supervised machine learning technique that constructs a predictive model. Here we use active learning to interactively query architecture data as a strategy to choose which candidate architectures to evaluate in a way that accelerates effective design search. Active learning is used to iteratively improve predictive model accuracy with strategically-selected training samples. The predictive model used here is an ensemble method, known as random forest. Several query strategies are compared. A circuit synthesis problem is used to test the active learning strategy; two complete data sets for this case study are available, aiding analysis. While active learning has been used for structured outputs, such as sequence labeling task, the interface between active learning and engineering design, particularly circuit synthesis, has not been well studied. The results indicate that active learning is a promising strategy in reducing the evaluation cost for the circuit synthesis problem, and provide insight into possible next steps for this general solution approach.
Dynamical Modeling of Gear Transmission Considering Gearbox Casing
Authors: Luo Yang , Baddour Natalie , Liang Ming
Published: November 2018

Much research has been carried out to investigate the dynamical response of a gear system because of its importance on vibration feature analysis. It is well known that the gearbox casing is one of the most important components of the gear system and plays an important role in signal propagation. However, its effects have widely been neglected within the dynamic simulations and few dynamic models have considered the gearbox casing when modeling a gear transmission. This paper proposes a gear transmission dynamical model with the consideration of the effects of gearbox casing. The proposed dynamical model incorporates TVMS, a time-varying load sharing ratio, as well as dynamic tooth contact friction forces, friction moments and dynamic mesh damping coefficients. The proposed gear dynamical model is validated by comparison with responses obtained from experimental test rigs under different speed conditions. Comparisons indicate that the responses of the proposed dynamical model are consistent with experimental results, in both time and frequency domains under different rotation speeds.
Implicit Algorithm for Riccati Transfer Matrix Method for Multibody Systems
Authors: Tu Tianxiong , Wang Guoping , Rui Xiaoting , Zhang Jianshu , Zhou Xiangzhen
Published: November 2018

Rui method, namely the transfer matrix method for multibody systems (MSTMM) is a new and efficient method for multibody system dynamics (MSD) for its features as follows: without global dynamics equations of the system, high programming, low order of system matrix and high computational speed. Riccati transfer matrix method for multibody systems was developed by introducing Riccati transformation in MSTMM, for improving numerical stability of MSTMM. In this paper, based on Riccati MSTMM, applying the thought of direct differentiation method, by differentiation of Riccati transfer equations of rigid bodies and joints, generalized acceleration and its differentiation can be obtained. Combined with Backward Euler algorithm, implicit algorithm for Riccati MSTMM is proposed in this paper. The formulation and computing procedure of the method are presented. The numerical examples show that results obtained by first order accurate implicit algorithm proposed in the paper and the fourth order accurate Runge-Kutta method have good agreement, which indicates that this implicit method is more numerical stability than explicit algorithm with the same order accurate. The implicit algorithm for Riccati MSTMM can be used for improving the computational accuracy of multibody system dynamics.
A Method for Creating a Manufacturing Cost Heatmap Based Purely on Part Geometry
Authors: Fox Kelly A. , Massoni Brandon , Campbell Matthew I.
Published: November 2018

It is now common for computer-aided engineering tools to show a performance parameter — like von Mises stress — over the surface of a solid part. In this paper, a heatmap is generated for part cost where high values (shown in red) indicate regions with a high impact on manufacturing cost. This is accomplished by slicing the provided part many times in multiple orientations and evaluating the total costs of each side of the part at each slice. The costs from all the directions considered are combined to generate a heatmap to show how different regions affect cost, enabling the designer to make informed improvements to the part geometry. In this paper, our method for generating these heatmaps is presented with three primary manufacturing cost models: bar stock, forging, and metal 3D printing. In all cases, a machining operation is then applied to get to the final part shape. Results are shown to validate the approach and demonstrate its usefulness.
Dynamic Analysis of Slider Mechanisms With Consideration of Frictional Effect in the Slider
Authors: Han Jianyou , Cao Yang , Li Penghao
Published: November 2018

This paper deals with dynamic analysis of three methods for the slider in mechanisms. Three methods are introduced under three conditions (the influence of friction force is considered, the slider’s center of mass is not coincide with the hinge point, the slider and its guide have rotation motion). The dynamic analyses of the crank slider mechanism and the flying shear mechanism are given as examples by a developed software based on Visual C++ environment, and application scope of the three methods is concluded at the end of the paper. These results are useful for analyzing and designing mechanisms with sliders, such as choosing suitable slider materials or actuators.
Design and Analysis of a Cross Trapezoid Spatial Compliant Device With Variable Stiffness
Authors: Zhang Zhuang , Chen Genliang , Kong Lingyu , Wang Hao
Published: November 2018

This paper presents a novel design of spatial compliant device with variable stiffness. The main concept of the device is to have two elastic trapezoid four-bar linkages arranging in orthogonal. The tool side of the device can switch between totally stiff and compliant by changing the arrangement of leaf springs and passive joints. Based on the principal axes decomposition of structural compliance matrix, the leaf springs are approximated by hyper-redundant linkages with rigid bodies connected by passive elastic joints. Hence, the nonlinear large deflection problems of the leaf springs can be solved efficiently in a mechanism way. In order to demonstrate the compliance of the proposed device, a numerical simulation is provided using the proposed approach. The result shows that the leaf springs in the compliant device are easy to be deformed and can not generate great force. Due to these characteristics, as an end-of-arm tool, the device has the ability to prevent hard collisions under the compliant status and finish precise positioning under the stiff status.
Turnability of a Small UGV With Individual Wheel Skid-Steering on Soft Terrain
Authors: Zhang Siyuan , Vantsevich Vladimir V.
Published: November 2018

Conventional turning mechanisms of wheeled skid-steer vehicles provide different velocities of the wheels at the left and right side while the wheels of each side are rigidly coupled and, thus, rotate with the same angular velocity. This turning principle has been employed for decades and provided high turnability of small unmanned ground vehicles (UGV) in both indoor and outdoor conditions with a high grip between pneumatic tires and surface of motion. However, as an analysis revealed, small UGVs habitually demonstrate non-sufficient turnability on deformable, extremely moisturized and heterogeneous terrains.

This paper proposes and develops new skid-steering inputs that are associated with de-coupled wheels, which are individually driven by either mechanical drivelines or electric motors. The skid-steering inputs are introduced as four kinematic discrepancy factors (KDF), which individually and, the same time in coordination with each other characterize kinematic and force variances of the UGV four drive wheels. In the paper, the KDF are explicitly determined as skid-steer variables through tire characteristics and parameters of individual mechanical and electric drivelines. The KDF are suitable for a lower vehicle sub-system control to individually manage the wheel torques.

The effectiveness of the skid-steering inputs is illustrated by analyzing vehicle understeer and oversteer maneuvers that are caused by various combinations of terrain conditions. A smooth and continuous transition from one to another KDF combination converts vehicle maneuvers and improves UGV turnability.
Topology Optimization for Discovery of Auxetic Origami Structures
Authors: Gillman Andrew , Fuchi Kazuko , Cook Alexander , Pankonien Alexander , Buskohl Philip R.
Published: November 2018

Origami, as it moves from an art to a scientifically useful technology, enables a rich design space given the numerous bifurcations that exist off the flat state. In this work, we utilize origami as a platform for design of auxetic metamaterials and employ topology optimization for the automated robust discovery of these structures. In particular, the mechanical analysis is performed with an efficient and accurate nonlinear truss element model that captures the geometric nonlinearities associated with origami folding, and modal analysis off the flat state enables access to the many bifurcating branches of folding. Here, objective functions are explored that target a desired in-plane Poisson’s ratio. The Miura-ori fold pattern, a commonly studied flat-foldable pattern, is considered as a verification study for the framework presented.
Dynamical Optimization of Tracked Vehicle Based on Riccati Transfer Matrix Method and PSO Algorithm
Authors: Wang Pingxin , Rui Xiaoting , Zhang Jianshu , Yu Hailong , Zhu Hongtao
Published: November 2018

Aiming at the problems of complex modeling and low calculation efficiency during dynamical optimization of tracked vehicles, a method for the closed-loop system called Riccati transfer matrix method for multibody system is proposed. In order to reduce the vibration acceleration of track shoes in the driving process, this paper uses the PSO algorithm and utilizes a strategy of decreasing the inertia weight to optimize the structural parameters of tracked vehicles. The research shows that the root mean square of vibration acceleration of track shoes above the support rollers is obviously reduced. This method provides a theoretical reference for the design of tracked vehicles and is beneficial to the dynamic design of complex systems.
Modeling and Simulation of a Displacement Controllable Active Suspension System
Authors: Liu Beibei , Xu Lin , Zhao Zhen , Abdelkareem Mohamed A. A. , Zou Junyi , Yu Jiaxing
Published: November 2018

Active suspension can adapt itself to the rigidity and the damping characteristics based on the vehicle dynamic state and the road condition, making the suspension in the best state of shock absorbing, which can increase the handling stability, the ride comfort and the passing ability of vehicles. As for strikingly rugged roads like off-road conditions, the traditional active suspension can hardly balance the contradiction between the wheel adhesion and the vertical accelerated speed of the body. In this paper, an active suspension in which the position of the vehicle body can be adjusted is proposed. In the proposed suspension, a series of electric cylinders are installed, which can actively adjust the position between the vehicle body and the suspension in order to achieve the purpose of controlling the relative body-wheels position. In this manner, AMESim is used to set up three suspension designs which include suspension supporter adaptation equipment with different locations in the system. Through simulation analysis, the paper has explored the feasibility of the vehicle attitude control of the three suspension designs under off-road conditions. The results proved that the active suspension system with adjustable body position can restrain the body roll or pitch efficiently in which this technology can be applied to the body attitude control when ORVs are at high speed.
Sliding Mode Set Point Control of a Six-DOF Cable-Suspended Parallel Robot With Tension Constraints and Uncertain Disturbances
Authors: Ren Ping , Sun Yunlong
Published: November 2018

This paper presents the design of a robust sliding mode controller for a six-degree-of-freedom cable-suspended parallel robot under uncertain disturbances. The control of cable-suspended parallel robots is quite challenging due to the unidirectional constraint of cable tensions. With the aid of interval analysis, a set of algebraic inequalities is obtained to establish the relationship between the cables’ tension constraints and the controller parameters. The sufficient conditions of the controller parameters satisfying the constraints are obtained for the set point motion within the robot’s static workspace. Numerical simulations are presented to verify the effectiveness of the proposed approach.
Development of Active Magnetic Bearing System Using Adaptive Feedforward Cancellation for Compensation and Analysis of External Forces in Rotating Machinery
Authors: Yabui Shota , Inoue Tsuyoshi
Published: November 2018

In this research, a rotor system using active magnetic bearing has been proposed to analyze for external forces in rotating machineries. Dynamics of the rotating machineries are influenced from the various external forces such as unbalanced forces, oil film forces at a journal bearing, and seal contact forces. The characteristics of the external forces are dependent on rotating speed and rotating orbit of the rotating shaft. In development the rotating machineries, the analysis of the characteristics of external forces is required under various rotating condition. The proposed system can compensate and analyze for the external forces by using the adaptive feed-forward cancellation (AFC).

By using AFC, the proposed system can realize the desired rotating conditions under acting the external forces and analyze the characteristics external forces. The effectiveness of the proposed system has been confirmed experimentally.
Design for Additive Manufacturing Inspired by TRIZ
Authors: Gross Jared , Park Kijung , Kremer Gül E. Okudan
Published: November 2018

With the rise in popularity of additive manufacturing (AM), relevant design methodologies have become necessary for designers to reap the full benefits from this technology. TRIZ is a problem-solving tool developed to assist with innovative and creative solutions. This paper aims to create a new TRIZ matrix specifically developed for designers using additive manufacturing. The TRIZ matrix offers designers general innovative design solutions to improve specific features of a design while not sacrificing the effectiveness of other features. The proposed matrix can help effective design decision making for additive manufacturing in an early design process as well as a redesign process. Also, a design for additive manufacturing (DfAM) worksheet is provided to enable users to easily find specific design solutions for certain additive manufacturing techniques based on the general solutions derived by the TRIZ matrix. To illustrate the potential of this AM specific TRIZ matrix, case studies are presented.
A Structural Integrity Approach for the Hybrid Adhesive Bonded Joints of a Smart Wheel for Racing Motorcycles
Authors: Carboni Michele , Mastinu Gianpiero , Muzzi Michele , Gobbi Massimiliano
Published: November 2018

A structural integrity approach has been applied to predict the safe operation of a hybrid adhesive bonded joint between a carbon fiber reinforced polymer and a magnesium light alloy. The joint is a structural part of a safety critical component, namely a smart wheel for a racing motorcycle. The influence of in-service loads on typical adhesive bonding defects is analyzed by finite element models and fracture mechanics concepts. Such an analysis has provided the needed targets for the ultrasonic inspection to be developed. The ultrasonic inspection was designed and validated experimentally by means of proper artificially defected lap joints and, then, performed on an actual smart wheel. A virtual inspection was performed, as well, by a proper computation for understanding the experimental results.
Study on Semi-Active Control of Armored Vehicle Suspensions Based on Rui Method
Authors: Wei Min , Rui Xiaoting , Zhu Wei , Yang Fufeng , Zhang Jianshu
Published: November 2018

In this paper, the dynamic model and simulation system of armored vehicle with semi-active control of magnetorheological fluid damper (MRFD) are presented. The MRFD for the semi-active suspension of armored vehicle is developed and tested. The effects of skyhook semi-active control on vertical, pitch and rolling vibration of armored vehicle body are evaluated under different road conditions with different speeds. The research results provide the theoretical basis and technical solutions for controlling the vehicle body vibration of armored vehicles.
Test Dynamics Method of Non-Full Loading Firing for Multiple Launch Rocket System Using Transfer Matrix Method for Multibody Systems
Authors: Miao Yunfei , Wang Guoping , Rui Xiaoting , Tu Tianxiong , Gu Lilin
Published: November 2018

This paper studies test dynamics method of non-full loading firing for multiple launch rocket system (MLRS) and provides a new test method for reducing rocket consumption in MLRS firing precision test. Based on the theories of launch dynamics and Rui method, namely the transfer matrix method for multibody systems (MSTMM), launch dynamics model, characteristic equations and dynamics response equations of MLRS are established. The launch and flight dynamic simulation system for MLRS is developed combining the Monte Carlo simulation technology. The simulated results of vibration characteristics, rocket initial disturbance, and firing precision are verified by modal test, pulse thrust test and firing test, which show the simulation system can more accurately reflect the dynamic characteristics of the actual system and its dynamics computation has sufficient accuracy. The relationship between the initial state of MLRS and the mean value and median error of the impact points are established. Based on the idea of equal initial disturbance, non-full loading firing test dynamics method is presented for reducing the rocket consumption in firing precision test, by optimizing the loading position, firing orders and firing intervals of the rockets. For a practical MLRS, a seven-shot test scheme is designed and tested. The experimental results show that the amount of the rockets in firing precision test is reduce by 61% compared with the conventional test method, which saves a lot of testing costs.
Modeling, Simulation and Experiment of Multibody System Launch Dynamics for Multiple Launch Rocket System
Authors: Li Bo , Rui Xiaoting , Zhou Qinbo , Zhang Jianshu , Gu Lilin
Published: November 2018

The purpose of this paper is to present a comprehensive multibody system dynamics model of a multiple launch rocket system (MLRS), and implement its simulation and experimental studies. The new version of transfer matrix method of multibody system and the launch dynamics theory are used in deriving the equations of motion coupled with rockets and barrels. The obtained model accounts for the complete process of the rockets’ ignition, movement in the barrels, airborne flight and landing. Launch dynamics of an 18-tube 122mm MLRS is investigated in this paper. Considering the effects of random factors, such as the impact and clearance between the rockets and barrels, the mass eccentricity and dynamic unbalance of the rockets and the thrust misalignment in this model, and combining the Monte Carlo method, the simulation of the dynamics of MLRS is carried out. Finally, the experimental implementation is proposed and the experimental results emphasize the feasibility of the multibody system launch dynamics model as a viable alternative for modeling accurately the dynamics characteristics of a practical MLRS. Meanwhile, the correctness of the numerical results is validated.
Folding a Rigid Flat Surface Around a Square Hub
Authors: Xu Runping , Zhang Xiao , Ma Jiayao , Chen Yan , Cao Yue , You Zhong
Published: November 2018

In the paper we investigate rigid origami patterns that enables a zero-thickness rigid flat surface to wrap around a square hub with the objective to package solar panels around a cubesat. After a detailed analysis on the rigid foldability of two known patterns, namely the winding membrane and box patterns, we conclude that neither of the patterns can be directly applied to wrap a solar panel, and thus a number of modified patterns are proposed that are capable of rigid folding with one or two degrees of freedom. Their folding sequences are presented and the advantages and shortcomings of the modified patterns are discussed so that designers can make an informed decision when making the selection. Finally we summarised our approach and briefly discussed the possibility to extend our approach to accommodate thick panels.