VCA Direct-Drive High Speed and Precision XY Table

In order to compensate for the limitation of conventional XY table used in semiconductor integrated circuits(IC) packaging and improve its speed and accuracy, a voice coil actuator (VCA) direct-drive high-speed and precision positioning XY table used in wire bonder was proposed. Also, a novel flexible decoupling mechanism was used in the positioning table, and the small moving mass enabled the positioning table to move at high speed and precision. XY table deformation interference caused by assembly error and instant interference generated by dynamic load moving with high speed and acceleration can be eliminated through the flexible decoupling mechanism. Considering the positioning table as lumped mass spring system,the dynamic equations of the mechanical system and the VCA were built according to the Newton mechanics principle and electromagnetic theory. Then the electromechanical coupling control model of the system was created through Laplace transform. Based on displacement PID controller, the loop-locked controlling algorithm of the positioning system was investigated. The dynamic control algorithm effectively improved the system dynamic performance. The precision test of the prototype machine was carried out, and the results validated the correctness of the model and the theory. Compared with traditional XY table, the table has higher speed, acceleration and positioning accuracy.     

A Unified Procedure for Deriving the Differential Equations of Electrical and Mechanical Systems

Based on energy considerations, it is possible to obtain the differential equations of motion of any physical system. A statement of equilibrium involving operations on energy functions is the Lagrange equation d / OT a7' D aOV dt (aq,) -aq aq + aq. Providing that the kinetic energy T, potential energy V, and dissipation function D can be written, the differential equations of the system are obtained by following a straightforward systematic procedure. It is not necessary to employ Kirchhoff's laws or Newton's force law to obtain the equations of electrical and mechanical systems. Rather, the two kinds of systems fall within the scope of this general method. The energy method is particularly useful in dealing with electromechanical systems and with mechanical systems that combine rotation and translation. Nonlinear as well as linear systems can be handled with equal ease. Versatility of the method is shown by its application to various examples, chosen in more or less increasing order of complexity. A set of tables is provided, listing the energy functions for each basic type of electrical, mechanical and electromechanical element. Those charged with teaching students the different disciplines of dynamics and electric circuits should find herein a common meeting ground wherein one general method suffices to yield the necessary differential equations.     

浅析煤矿机电管理

煤矿机电设备运行状况直接关系到煤矿生产,发生机电事故的原因很多,如何加强机电管理,降低机电事故是煤矿机电管理的首要任务。     

嵌入式系统在机电控制中的应用

在信息化时代中,嵌入式系统与网络进行远程互动已是大势所趋．在机电控制中应用嵌入式系统．可在增加机电系统功能的同时降低机电系统的功耗和降低系统成本．嵌入式系统的这些优势为其在机电控制系统中的广泛应用奠定了基础．笔者从介绍嵌入式系统和分析当前市场中的微处理器着手,介绍了嵌入式系统所应用的操作系统和嵌入式系统的外围设备及应用软件,通过分析网络化机电控制系统来说明嵌入式系统网络化的可行性和必要性．     

高职汽车专业学习领域课程体系的实践应用

为建立符合现代汽车维修行业需求的汽车机电人才培训体系,解决汽车维修行业高端技能型人才紧缺难题,中德职业教育汽车机电合作项目开发设计了学习领域课程体系。通过对学习领域课程一个客户委托的教学实施,阐述了高职汽车专业学习领域课程的教学模式、教学方法、教学进程等,从而提高了教学质量。     

转动系统相对论性动力学方程的Birkhoff表示

给出转动力学系统的相对论性ＰｆａｆｆＢｉｒｋｈｏｆｆ 原理和Ｂｉｒｋｈｏｆｆ 方程．证明：相对论性完整保守转动力学系统可以直接纳入相对论性转动Ｂｉｒｋｈｏｆｆ 系统动力学;一般相对论性完整转动力学系统先将运动方程表成显形式,然后实行Ｂｉｒｋｈｏｆｆ 化．并给出应用实例．     

A coupled thermal–hydraulic–mechanical–chemical (THMC) model for methane hydrate bearing sediments using COMSOL Multiphysics

Methane gas extraction by a deep well installed in methane hydrate bearing sediments (MHBS) found in deep subsea and permafrost regions is a coupled thermal–hydraulic–mechanical–chemical (THMC) process. The key processes include heat convection between layers, local deformation due to compaction, and stress relaxation caused by damage of the bonded structure. As improper production may induce formation compaction, sand production, and wellbore failures, a numerical code is needed to simulate the THMC processes during methane gas production so that geomechanics and production risks can be quantified. In this study, a nonlinear THMC model was implemented in the partial differential equations (PDE) and structural mechanics module of the COMSOL Multiphysics^® finite element code. This paper describes the non-linear coupled governing equations of the mechanical behavior during hydrate dissociation. In particular, it introduces a new thermodynamics-based constitutive model to simulate the mechanical behavior of hydrate bearing sediments. The performance of the newly developed code was examined by comparing the computed results with test data and other simulation results. The differences between fully coupled and semi-coupled models were analyzed. For example, heterogeneous turbidite layers observed in the Nankai Trough were modeled, and behaviors such as heat convection between different layers, shear stress and strain concentration were examined.     

高职机电一体化专业发展模式探究

文章首先分析了目前高职机电一体化专业的现状,然后针对目前的现状,结合天津冶金职业技术学院机电一体化专业,提出了机电一体化专业未来的发展模式:机制体制要创新、课程体系设置要合理、实训基地要生产化。     

船舶电气工程专业人才培养模式与知识体系研究

随着全球化的发展,远洋船舶数量和吨位不断增加。船舶动力系统大多由机电干部负责管理、使用和维护,这对电气工程专业机电干部的个人素质和能力提出了更高要求。为了深入了解和掌握电气工程专业毕业学员能否胜任船舶机电干部岗位人才需求,文章通过调查问卷方式获取电气工程专业人才培养模式与知识体系的优点和存在的问题,作为后续工程专业人才培养模式教学改革的依据。     

基于Unity 3D的机电产品虚拟拆装实验系统

由于受到实验对象、场地等条件限制,一些工科专业的产品拆装实验很难达到实验要求,为此提出一种使用虚拟仿真实现机电产品拆装实验的方法。该方法基于Unity3D搭建三维可视化交互场景的方法,以常见的4种机电产品为原型,采用B/S架构搭建机电产品虚拟拆装实验系统。将外部三维模型进行轻量化处理后导入Unity3D中,在系统中设计了包括场景交互、机电产品拆装过程交互和Web-Unity3D交互等功能。Unity3D模型发布为WebGL后嵌入网页端,在网页端动态展示了机电产品的工作原理与拆装过程。本系统兼容性强、无安全隐患,在工程类实验教学中取得良好效果,提升了学生学习兴趣。     

圆柱壳体非线性分析关键技术研究

ANSYS是通用的、大型的有限元分析CAE软件,使用ANSYS软件可以求解静态和瞬态非线性问题.本文在分析了圆柱薄壳结构的特点、分类和应用的基础上,对圆柱壳体的稳定性进行了研究,建立了圆柱壳体非线性力学方程.在ANSYS平台下,对典型的圆柱壳体进行了仿真,为进一步深入研究圆柱壳体非线性问题提供了借鉴.     

高职机电一体化专业教学质量动态管理体系的研究

本文以浙江工业职业技术学院高职机电一体化专业的教学质量动态管理体系为研究个案，重点阐述了高职院校建立教学质量动态管理体系的目的、作用，并对高职机电一体化专业的教学质量动态管理体系的内容及实际应用作了详细分析．为同类高职院校机电一体化专业的教学质量管理工作提供了一种模式，也为其他专业教学质量管理的建立提供了借鉴。     

高斯光束辐照下光学薄膜基底温度场有限元分析

基于热传导方程,利用有限元分析方法,利用MSC．Marc有限元软件建立了激光辐照下光学薄膜基底温度场的三维模型,研究了光学薄膜基底在高斯光束辐照下的温度场分布,并进行了分析。     

仿真技术在电气控制技术教学中的应用

在许多高职院校的机电一体化、电气自动化等相关专业都开设了"电气控制技术"或与电气控制技术相关的课程。该课程是一门专业实践性要求很高的课程,因此在教学过程中,如能用真实现场实物演示教学,学生易于理解,效果也好,但成本较高。为解决在教学中存在的这些矛盾,我们结合当前仿真技术,以宇龙机电仿真和组态软件为平台提供了一种简便的电气控制技术的仿真教学方案。     

基于项目驱动的工业机器人实验设计和开发

工业机器人综合了机械、自动化、计算机等多学科技术,是智能制造系统中的重要单元。在课程实践中,将工业机器人作为一种机电产品进行系统设计和控制操作。基于ABB六轴工业机器人实验平台,以企业工程应用和自主设计任务作为创新性设计实验项目内容,进行工业机器人三维建模、控制系统设计、程序开发和动作执行。在工业机器人课程中应用后,取得了明显的效果,有助于学生更好地掌握工业机器人基本理论和项目开发,培养了学生的设计开发能力、实践动手能力和创新设计能力,并能使学生更好地理解工业机器人单元在智能制造系统中的作用。     

谐振子含时薛定谔方程的辛算法研究

辛算法是最近出现的一种哈密顿力学计算方法,我们将它应用于求解量子力学中线性谐振子的含时薛定谔方程,自编程序进行了计算,并与通常算法作了比较,计算结果表明,辛算法是用于求解含时薛定谔方程等一类偏微分方程的一种优秀的数值计算方法。     

多课程知识体系融合的电液比例控制教学改革

为了满足对复合型人才的需要,太原科技大学对电液比例控制系统分析与设计等课程的相关教学和实验进行了整合、设计,以便提高学生对各专业课程之间的理解。整合后形成的综合实验教学模式,其教学目标、教学设计、具体实施方案、实验设备及教学效果,贯通了学生在PLC、电液比例控制系统分析与设计和液压与液力传动的知识,提高了机械工程专业学生在进行复杂的机电液系统设计时的全局掌握能力,增强了综合利用机电液一体化技术进行创新的能力和实践能力。     

有限差分法在一维输运方程定解中的运用

有限差分方法就是一种数值解法,在一维输运方程定解中可以巧用它来解题,把表示变量连续变化关系的偏微分方程离散为有限个代数方程,然后利用电子计算机求此线性代数方程组的解。     

Modelling and Simulation of System Dynamics of Hybrid-Driven Precision Press

Different from conventional mechanical systems with single degree of freedom (DOF),the main idea of the system of hybrid-driven precision press is to combine the motion of a constant speed motor with a servomotor via a two-DOF mechanism to provide flexible output. In order to make the feasibility clear, this paper studies theoretically the dynamic characteristics of this hybriddriven mechanical system. Firstly,the dynamics model of the whole electromechanical system is set up by combining dynamic equations of DC motors with those of two-DOF nine-bar mechanism deduced by the Lagrange‘s formula. Secondly through the numerical solution with the fourth Runge-Kutta, computer simulation about the dynamics is done, which shows that the designed and optimized hybrid-driven precision press is feasible in theory. These provide theoretical basis for later experimental research.     

松软煤岩大直径长钻孔失稳控制方法研究

针对深部钻孔软弱围岩层的岩石力学性质,通过软件对巷道顶板、底板等不同层位大直径钻孔的岩石力学特征进行了弹塑性状态下大直径钻孔二次应力分布特征、弹塑性区的变化规律以及钻孔径向位移的变化趋势数值模拟,并建立了数值模型,得出复杂条件下深部煤岩弱结构大直径长钻孔失稳的力学特性,给出了解决大直径钻孔稳定的关键技术和固孔工艺方法。