热致形状记忆聚合物非接触式驱动的研究进展

非接触式驱动是将能量直接作用于热致形状记忆聚合物上,驱动其回复初始形状的驱动方法。从电驱动、激光驱动和磁场驱动等方面概述了非接触式驱动的实现方法、原理,综述了近年来热致形状记忆聚合物非接触式驱动的研究进展,并展望了非接触式驱动的可能应用领域与前景。     

直接驱动卡进电动机伺服系统新型驱动控制器的研究

采用模糊控制方法,设计了直接驱动步进电机位置伺服驱动控制器。实验结果表明,这种新型的驱动控制器使直接驱动系统具有较高的性能。     

直接驱动步进电动机伺服系统新型驱动控制器的研究

采用模糊控制方法 ,设计了直接驱动步进电机位置伺服驱动控制器。实验结果表明 ,这种新型的驱动控制器使直接驱动系统具有较高的性能     

基于特性图分析的科氏质量流量计模拟驱动研究

针对模拟驱动流量管易停振、启振慢等问题,利用特性图法,分析了经典模拟驱动的驱动特性,并对两种典型的模拟驱动改进方法进行了研究,提出一种改进的差分驱动.研制4种模拟驱动的实现电路,进行了气液两相流驱动实验和启振实验.实验结果表明,新型模拟驱动的驱动信号幅值更稳定,启振更快;差分驱动显著提高了驱动能量;与经典模拟驱动相比,...     

电气驱动更加经济——10MW级高压变频器在合成氨装置主机系统中的应用

本文通过对现有40万t合成氨装置主压缩机组驱动系统分析，指出了其中存在的问题。针对性提出采用电气驱动替代“锅炉＋汽轮机”驱动的新思路；通过对两种驱动形式的经济性比较，技术可行’陛分析，阐述了该新型驱动形式的可行性和良好应用前景。     

科氏质量流量计的3种驱动方法研究

针对科氏质量流量计的驱动问题,比较和实现了模拟驱动、半数字驱动以及全数字驱动的驱动方法。基于高准CNG050型科氏质量流量传感器,研制基于DSP的二次仪表,进行实际驱动实验,分析各自驱动中存在的问题。实验结果表明,这3种驱动方案性能逐次提高。     

VxWorks下多串口卡驱动程序设计初探

本文以OX16PCI958串口芯片的多串口卡驱动为例,研究和分析了VxWork串口驱动的工作原理,并在此基础上对SCC驱动和tty驱动工作原理进行简单阐述,同时介绍了PPC体系结构微处理器的串口驱动程序设计的方法和步骤,以期为VxWorks下多串口卡驱动程序设计提供有价值的参考。     

大型机电驱动系统的优化--现代电子数据处理方法的能力和限制

 大功率特殊电驱动大多数受到技术可行性的限制,它要求持续采用先进的、柔性的计算方法．这种驱动系统的优化前提是在考虑了所实施的设备系统间的各种相互作用后,对过程作出全面的、专业性的评估．讨论在计划和设计大型定制电气驱动时,合理应用高效的电子数据处理方法所面临的机遇和风险．     

基于WDM-NDIS体系的USB网卡驱动程序设计

为了在Windows下实现USB网卡驱动程序,本文根据NDlS_WDM驱动模型,分析了NDIS_WDM模型的内在运行机制,提出了一个USB网卡驱动的设计方案,并重点讨论了NDIS和USB设备栈的交互过程,围绕这个过程,使用Windows DDK 2003开发包及VC开发工具.写出了USB网卡驱动程序的初始化和发送接收过程的关键代码.实现了对CY3681评估板的发遗接收操作.     

嵌入式无线接入点网络驱动的设计与实现

分析了嵌入式Linux系统下网络驱动的体系机构和工作原理，结合PCMCIA驱动接口，着重论述了嵌入式Linux无线接入点网络驱动的基本软件模型和实现流程, 给出了网络驱动的性能测试结果。     

介电弹性体驱动单元的动态特性分析

针对不同电压载荷情况下介电弹性体驱动单元的动态特性,考虑材料非线性、介电常数变化和惯性效应等因素的影响,从热力学能量转化的角度得到了基于Ogden应变能函数的介电弹性体驱动单元的二阶常微分运动方程,并分析了系统的动态响应及模型几何尺寸的影响。结果表明:介电弹性体驱动单元动态响应的振幅由电场强度决定。在恒定场强下,随着电场强度幅值的增大,驱动单元的振幅将随之增大、振动频率将随之减小;在简谐场强下,随着电场强度频率的增大,驱动单元将发生共振,且共振频率将随电场强度的增大而减小。     

An investigation of shape memory alloys as actuating elements in aerospace morphing applications

Two innovative actuating concepts for aerospace morphing applications, based on shape memory alloys (SMAs), are proposed. The first concept investigates a composite plate incorporating embedded SMA wires. A nonlinear auto regressive with exogenous excitation model is proposed for controlling single-cycle/multi-cycle loading conditions of the SMA wires. The second actuating concept studies a novel rib configuration, which incorporates a compliant mechanism for enabling aerofoil's leading edge morphing. Different rib-compliant mechanism concepts are designed and analyzed. The most efficient rib concept is experimentally characterized. The experimental results from both actuating concepts showed good agreement with the respective numerical.     

Optimization of actuating torques in multi-bar prosthetic joints with springs

This article presents the optimization of actuating torques in multi-bar prosthetic joints with springs. First, a general model of the planar multi-bar single-loop mechanism with springs for the prosthetic joint is proposed. Secondly, the dynamic matrix of the mechanism is solved by analysing the force condition of a single bar, with the external forces and torques, the forces and torques of the springs as well as the actuating torques being considered. Thirdly, a general optimization method of actuating torques is proposed by taking into account different spring installation situations. Finally, two prosthetic joint examples are presented to show the detailed optimization process, and the effectiveness of the proposed optimization is verified by simulation and experiment. The results prove that the addition of springs in multi-bar prosthetic joints can reduce the absolute values and fluctuations of actuating torques, leading to better energy saving.     

THUNDER元件热机电耦合动力学分析

针对THUNDER型压电驱动器这一类特殊结构形式,提出一种包含4个位移节点,8个温度节点和2个电势节点的热机电耦合混合有限元模型,并基于虚功原理推导了热机电耦合有限元方程。针对物理属性截然不同的冷却阶段、再极化阶段和驱动阶段开展了动力学研究,并利用初始位移这一变量将它们有机地联结起来;系统地分析了该类驱动器的热机电耦合问题。数值算例表明:该混合有限元模型具有良好的计算精度;THUNDER型压电驱动器的驱动性能与其制造过程密切相关,且其驱动位移与外载荷的凹曲线关系使其具有良好的综合驱动性能;在实际应用中,当温度发生变化时,热应变对驱动性能具有重大影响,而焦电效应的影响相对较小但仍十分明显,体现出对THUNDER型压电驱动器开展热机电耦合动力学研究的重要性。     

Acoustic Nonlinearity Parameter Due to Microplasticity

Acoustic nonlinearity (which is quantified in terms of an absolute material parameter, the acoustic nonlinearity parameter, β) can be caused by several sources, one of which is the elastic-plastic deformation of the material. This paper develops a model to quantify the acoustic nonlinearity parameter due to elastic-plastic deformation. This new model is applicable to general anisotropic elastic-plastic materials with existing microplasticity strains due to either monotonic or cyclic loading. As an example, the developed model is applied to calculate the acoustic nonlinearity parameter of a single crystal copper specimen subjected to cyclic fatigue loading. It is found that the acoustic nonlinearity parameter of this specimen increases monotonically with increasing fatigue cycles.     

The Simulation of Diaphragm Deflection Actuated by Shear Mode Piezoelectric Actuator in Microdroplet Ejector

A shear mode piezoelectric actuator is applied to deflect the diaphragm of pressure chamber in the droplet ejector or inkjet printhead. The deflection of the bulge-diaphragm and resulting swept volume is analyzed by analytical and numerical method. With free-body treatment of the model, the analytical exact solutions for the two free bodies of bulge-diaphragm and piezoelectric beam were obtained. Also, the numerical solution by ANSYS is obtained to verify the analytical result. Besides, the whole-model solution coupling the bulge-diaphragm and piezoelectric beam together was obtained by ANSYS to compare with the result of free-body analysis. In order to estimate the maximum actuating force and deflection of the shear mode piezoelectric actuator, the diaphragm characteristic curve is obtained in the free-body analysis, which presents the decreasing tendency of the central deflection with the increase of anti-deflection (or reaction) force under certain actuating voltage. Also, the diaphragm characteristic curve is obtained showing the central deflection in proportion to the action force. By combining both kinds of curves, the actuated central deflection of the bulge-diaphragm can be obtained under certain actuating voltage. Finally, both linear relations including diaphragm central deflection in proportion to actuating voltage and volume displacement in proportion to diaphragm central deflection are obtained.     

基于磁流变技术的对称气动缸动力机构

针对传统的阀控对称气动缸动力机构,将普通对称式气缸和自制的磁流变液(MRF)阻尼器串联构成一种新型的磁流变(MR)对称动力机构.首先介绍了该动力机构的工作原理,然后对机构进行数学建模,通过MATLAB的仿真进行特性分析.分析结果表明,该种新型磁流变对称动力机构能够克服传统的气动伺服系统的缺点,具有高响应、高刚度、阻尼任意可控可调等一系列特殊性能.为解决非线性严重的气动伺服系统难以控制的问题寻求了一条很有前景的新途径.     

Basic design guidelines for SMA/epoxy smart composites

The actuating ability and reliability of shape memory alloy (SMA) hybrid composites were studied in this paper. Results showed that by selecting small hysteresis SMAs such as TiNiCu alloy, SMA hybrid composites have a linear stress–temperature behavior, which is relatively easy to control. The curing process of the epoxy matrix does not affect significantly the actuating ability of the embedded TiNiCu alloy wires. A moderate prestrain of the TiNiCu wires is preferred when giving attention to both the mechanical properties and the reliability of the TiNiCu hybrid composites. Additional reinforcing fibers with a negative thermal expansion coefficient such as Kevlar fibers are helpful to strengthen the reliability of the interface and enhance the actuating ability of the SMA hybrid composites. Based on the experimental results, some basic guidelines for designing shape memory hybrid composites were proposed.     

电荷平衡式低频电压-频率变换器非线性误差的分析与补偿

在合理构造V/F模型的基础上,用严格的数学方法导出了电荷平衡式电压-频率变换器(VFC)的低频传输特性,得到了主要非理想因素影响下的非线性表达式,提出了非线性的控制和补偿设计方法。据此实现的DVF-1型智能数字电压频率测量仪的VFC系统,满度非线性误差达到了3×10~(-6),远优于NSC公司相同原理精密器件LM331的1×10~(-4)非线性水平。     

基于模型预测控制的高速柔性并联机构振动控制

由于高速柔性并联机构系统的非线性和不确定性,提出一种鲁棒模型预测振动控制策略以抑制系统的振动响应。以压电陶瓷为作动器,电阻应变片为传感器,采用有限元方法和模态截断技术建立机构不精确动力学模型。机构动力学模型中的非线性因素、耦合因素及系统高阶模态影响作为扰动,将模态力视为不确定扰动,并且考虑输出噪声对系统的影响,建立系统动态响应的预测模型,以预测输出值。采用Kalman滤波估计器估计系统状态量,以控制电压及其变化率为约束条件,将系统性能指标和约束条件化为一个标准二次规划优化问题,通过求解这一优化问题来得到最优控制输出,形成滚动优化控制输出来抑制系统振动响应。采用表征作动能量的可控性指标和表征观测信号能量的可观性指标,确定作动器和传感器的最优位置。以新型2自由度并联机构为实例,采用实验模态方法得到系统的前2阶固有频率和阻尼比,与有限元方法得到的结果比较分析表明理论模型不精确。基于该模型采用dSPACE实时仿真系统和MATLAB/Simulink搭建鲁棒控制系统,进行振动主动控制试验研究。试验结果表明,所设计的控制器能有效地抑制柔性构件产生的弹性振动,验证了控制器的有效性和鲁棒性。