An omni-directional mobile millimeter-sized microrobot with 3-mm electromagnetic micromotors for a micro-factory

This paper presents an omni-directional mobile microrobot for micro-assembly in a micro-factory. A novel structure is designed for omni-directional movement with three normal wheels. The millimeter-sized microrobot is actuated by four electromagnetic micromotors whose size is 3.1 mm × 3.1 mm × 1.4 mm. Three of the micromotors are for translation and the other one is for steering. The micromotor rotors are designed as the wheels to reduce the microrobot volume. A piezoelectric micro-gripper is fabricated for grasping micro-parts. The corresponding kinematics matrix is analyzed to prove the omni-directional mobility. A control system composed of two CCD cameras, a host computer and circuit board is designed. The macro camera is for a global view and the micro camera is for local supervision. Unique location methods are proposed for different scenarios. A microstep control approach for the micromotors is presented to satisfy the requirement of high positioning accuracy. The experiment demonstrates the mobility of the microrobot and the validity of the control system.     

Combining series elastic actuation and magneto-rheological damping for the control of agile locomotion

All-terrain robot locomotion is an active topic of research. Search and rescue maneuvers and exploratory missions could benefit from robots with the abilities of real animals. However, technological barriers exist to ultimately achieving the actuation system, which is able to meet the exigent requirements of these robots. This paper describes the locomotion control of a leg prototype, designed and developed to make a quadruped walk dynamically while exhibiting compliant interaction with the environment. The actuation system of the leg is based on the hybrid use of series elasticity and magneto-rheological dampers, which provide variable compliance for natural-looking motion and improved interaction with the ground. The locomotion control architecture has been proposed to exploit natural leg dynamics in order to improve energy efficiency. Results show that the controller achieves a significant reduction in energy consumption during the leg swing phase thanks to the exploitation of inherent leg dynamics. Added to this, experiments with the real leg prototype show that the combined use of series elasticity and magneto-rheological damping at the knee provide a 20 % reduction in the energy wasted in braking the knee during its extension in the leg stance phase.     

Design optimization of an electromagnetic actuation based valveless micropump for drug delivery application

Microsystem Technologies - A valveless micropump based on an electromagnetic actuation for drug delivery application has been designed. The parametric studies are performed to examine the effects...     

Finite element method to 3-dimensional simulation of semiconductors

Different semiconductor models are presented. The mainly used numerical methods to simulate these models are shortly compared to favour the FEM. Some considerations to the choice of the elements, the form functions, and the boundary conditions are made, where the case of boundary conditions of the 3.kind requires a special projection to optimize accuracy. The executable programs BIFIN and TRIFIN are characterized shortly.     

New solitonic solutions to a (3+1)-dimensional Jimbo-Miwa equation

Performing computerized symbolic computation, we are able to present new analytic solutions of a (3+1)-dimensional Jimbo-Miwa equation which does not pass any of the conventional integrability tests. Applying the generalized tanh method, we have found such exact solutions as both the nontraveling-solitonic and traveling-solitary waves.     

Efficient 3-dimensional GLV method for faster point multiplication on some GLS elliptic curves

We discover that two distinct efficient endomorphisms can both exist on some Galbraith-Lin-Scott (GLS) elliptic curves Galbraith et al. (2009) [4]. By using them we generalize the Gallant-Lambert-Vanstone (GLV) method Gallant et al. (2001) [5] for faster point multiplication on these curves to dimension 3, and give some implementation result which shows that our 3-dimensional GLV (3GLV) method runs in 0.897 the time of 2-dimensional GLV (2GLV) method as Galbraith et al. did in Galbraith et al. (2009) [4] for the point multiplication on these curves.     

New exact solutions of the (n+1)-dimensional sine-Gordon equation using double elliptic equation method

In this paper, the (n+1)-dimensional sine-Gordon equation is studied using double elliptic equation method. With the aid of Maple, more exact solutions expressed by Jacobi elliptic functions are obtained. When the modulus m of Jacobi elliptic function is driven to the limit 1 and 0, some exact solutions expressed by hyperbolic function solutions and trigonometric functions can also be obtained, respectively.     

Oscillator driven central pattern generator (CPG) system for procedural animation of quadruped locomotion

Multimedia Tools and Applications - In this paper a procedural animation framework is developed and discussed, which consists of a oscillator based Central Pattern Generator (CPG) system. This CPG...     

实时界定雷达电磁互扰区域的三维可视化方法

为了便于多方位、多角度观察和分析舰艇编队中雷达电磁互扰的区域, 利用等值面的分界特性, 通过使用能流密度和干扰余量来表现舰艇编队中雷达电磁互扰的程度, 提出使用递进式栅格采样的极值八叉树快速重构等值面的方法, 还提出使用等值面差别显示的方法建立实时交互的三维显示图和俯视、前视、侧视的动态切面图, 来动态显示舰艇编队雷达电磁互扰的仿真结果。通过对6艘舰艇共16部单脉冲雷达的仿真, 实验结果表明该方法可行、有效。该方法还可以应用到其他电磁环境的实时三维可视化中, 也可以应用在研究和预防无人机被雷达电磁干扰的三维仿真中。     

Microthermoforming of nanostructured polymer films: a new bonding method for the integration of nanostructures in 3-dimensional cavities

In this paper an approach will be presented to integrate selective nanostructured surfaces in 3-dimensional cavities. For this purpose, the technologies of nanoimprinting, micro- thermoforming, and thermal bonding will be combined. In a first step the nanostructures are patterned onto the surface of polymer films by nanoimprinting. In a second step the structured film is formed into already moulded polymer cavities by microthermoforming. During this micro-thermoforming step, a thermal bonding process is accomplished in parallel. Geometrical modifications of the nanostructures due to the uniaxial and biaxial stretching of the polymer film are measured, described, and compared with an analytical model.     

An integral equation method for inversion of electromagnetic soundings

The analogy of the problem of electromagnetic induction sounding of the earth's conductivity-depth profile using a two perpendicular-loop system to the general remote sensing problem of the atmosphere is pointed out. The induction sounding problem has been reduced to the solution of a new integral equation of Fredholm type. Kernels of the integral equation are evaluated, and their characteristics are investigated. A nonlinear relaxation inversion technique is suggested for the solution. Convergence of the solution, information content of measurements, and the range of possible retrieval of the conductivity profile are discussed.     

Application of the utility function method for behavioral organization in a locomotion task

The generation of a complete robotic brain for locomotion based on the utility function (UF) method for behavioral organization is demonstrated. A simulated, single-legged hopping robot is considered, and a two-stage process is used for generating the robotic brain. First, individual behaviors are constructed through artificial evolution of recurrent neural networks (RNNs). Thereafter, a behavioral organizer is generated through evolutionary optimization of utility functions. Two systems are considered: a simplified model with trivial dynamics, as well as a model using full newtonian dynamics. In both cases, the UF method was able to generate an adequate behavioral organizer, which allowed the robot to perform its primary task of moving through an arena, while avoiding collisions with obstacles and keeping the batteries sufficiently charged. The results for the simplified model were better than those for the dynamical model, a fact that could be attributed to the poor performance of the individual behaviors (implemented as RNNs) during extended operation.     

A smooth impact drive mechanism actuation method for flapping wing mechanism of bio-inspired micro air vehicles

Microsystem Technologies - In this paper, a smooth impact drive mechanism (SIDM) actuation method for flapping wing mechanism which can be used in bio-inspired micro air vehicles is proposed. The...     

Novel application of FO-DPSO for 2-D parameter estimation of electromagnetic plane waves

Neural Computing and Applications - Parameter estimation of plane waves emitted by sources lying in Fraunhofer zone is one of the active areas of research for last few decades. In this study,...     

开关磁阻电动机电磁干扰抑制方法研究

以8/6结构开关磁阻电动机调速系统为研究对象,分析了其转速闭环条件下磁阻电动机状态对H桥斩波开关的影响,并给出了磁阻电动机在2种不同的混沌态下时斩波开关电压功率谱的计算方法。结合开关磁阻电动机非线性仿真模型和特征值求概率密度分布的方法,利用复化辛普森公式计算2种情况下的系统斩波管电压功率谱,证明了混沌对降低系统电磁干扰的有效性。Matlab仿真和实验结果与理论分析结果一致,证实了混沌在提高电力传动系统电磁兼容性能方面具有良好的应用前景。     

Application of the incomplete Cholesky factorization preconditioned Krylov subspace method to the vector finite element method for 3-D electromagnetic scattering problems

The incomplete Cholesky (IC) factorization preconditioning technique is applied to the Krylov subspace methods for solving large systems of linear equations resulted from the use of edge-based finite element method (FEM). The construction of the preconditioner is based on the fact that the coefficient matrix is represented in an upper triangular compressed sparse row (CSR) form. An efficient implementation of the IC factorization is described in detail for complex symmetric matrices. With some ordering schemes our IC algorithm can greatly reduce the memory requirement as well as the iteration numbers. Numerical tests on harmonic analysis for plane wave scattering from a metallic plate and a metallic sphere coated by a lossy dielectric layer show the efficiency of this method.     

Case-based retrieval of 3-dimensional shapes for the design of metal castings

This paper describes research into retrieval based on 3-dimensional shapes for use in the metal casting industry. The purpose of the system is to advise a casting engineer on the design aspects of a new casting by reference to similar castings which have been prototyped and tested in the past. The key aspects of the system are the orientation of the shape within the mould, the positions of feeders and chills, and particular advice concerning special problems and solutions, and possible redesign. The main focus of this research is the effectiveness of similarity measures based on 3-dimensional shapes. The approach adopted here is to construct similarity measures based on a graphical representation deriving from a shape decomposition used extensively by experienced casting design engineers. The paper explains the graphical representation and discusses similarity measures based on it. Performance measures for the CBR system are given, and the results for trials of the system are presented. The competence of the current case-base is discussed, with reference to a representation of cases as points in an n-dimensional feature space, and its principal components visualization. A refinement of the case base is performed as a result of the competence analysis and the performance of the case-base before and after refinement is compared.     

On closed-form approximations for the free energy of 3-dimensional ising model

We show that it is possible to construct closed-form approximations to lnZ ₃, which are suitable generalizations of the Onsager formula for lnZ ₂, and whose high- and low-temperature series expansions have the same structure as the exact ones.