压电自感知微夹钳

研制了不需要外部附加微位移与微力传感器、采用自感知方法来获取压电微夹钳的钳指位移与夹持力的压电自感知微夹钳。根据压电陶瓷晶片在驱动电压与外力作用下发生变形会在其表面产生电荷的思想,提出了基于积分电荷的钳指位移与夹持力的自感知方法;基于Jan G.Smits的压电悬臂梁弯曲变形理论,给出了钳指位移与夹持力的自感知表达式,即用钳指上压电陶瓷晶片表面的电荷来表达钳指位移与夹持力。设计了获取晶片表面电荷的积分电路,给出了其平衡条件为晶片电容与其绝缘电阻之积同积分电容与反馈电阻之积相等。自感知验证实验结果表明:修正后在31.59μm最大钳指位移范围内的自感知位移最大偏差为0.78μm;在35.91mN最大钳指夹持力范围内的自感知夹持力的最大偏差为0.24mN。实验结果验证了所提自感知方法是有效的。     

协同式CO_2焊短路过渡模糊控制系统研究

介绍了一种在波形控制基础上,采用电弧自身传感的协同式模糊　控制方法对焊接过程参数进行实时控制的逆变式ＣＯ２焊机控制系统。它通过电弧自身传感　对ＣＯ２焊接过程有重要影响的短路过渡频率的检测,通过模糊处理和模糊判决之后,实时　的对电弧电压进行控制,以保持焊接过程中规范参数的协同匹配关系。试验结果表明,采用　该控制系统的焊机,实现了焊接规范参数的自动匹配和自动调节,同时明显改善了焊缝成形　和降低了焊接过程中的飞溅。     

Signal separation technology for diphase opposition giant magnetostrictive self-sensing actuator

The structure and principle of a new type of a diphase opposition giant magnetostrictive self-sensing actuator is introduced. A bridge analysis model based on variable inductance is established. Dynamic balance separation technology for the giant magnetostrictive self-sensing actuator comes true by the least means square (LMS) self-adapting algorithm. The scheme design of one important part of the circuit with the real-time separation circuit of the dynamic balance signal based on a digital signal processor is obtained. The part of the signal separated circuit is designed, which includes logarithmic-antilog practical multiplication circuit, amplifying circuit, filter circuits, and amplifier circuit. Based on the embedded system simulation software—PROTUES, the simulation effect of the circuit that separates the sensing signal from the mixed signals is obvious, which indicates that the circuit can rapidly and stably work. Moreover, the structure is simple, reliable, and meets the practical requirement.     

双定子直线振荡电机动子位移自传感技术研究

基于建立的双定子直线振荡电机系统数学模型,提出了电机动子位移自传感算法,通过对于电机端电压及电流信号的处理实现了动子位移的自传感.在此基础上,通过实验对此算法进行了验证.实验结果显示,在有效行程范围(20 mm)内.定频变行程和谐振点变行程控制方式下的估算行程的最大绝对误差分别为0.4 mm和0.3 mm,最大相对误差分别为4.76%和3.7%,可以满足控制要求.此算法可用于直驱压缩机的变行程控制及上死点控制.     

Range-expansion technology and fatigue performance study on the self-sensing steel strand with an embedded fibre Bragg grating sensor

For the protection of a fragile optical fibre with a fibre Bragg grating (FBG) sensor, the encapsulating method of embedding the FBG sensor in a longitudinal groove set in the central wire of the steel strand is presented. According to the theoretical analysis of the strain transfer and sensing capacity between the embedded FBG sensor and substrate, the requirements for the cross-sectional size of the groove and bond-length of the optical fibre to the self-sensing steel strand are discussed. A prepressure technology is proposed to overcome the problem of low ultimate tensile strain of FBGs. Experiments for range-expansion with different prepressure values were carried out. The results showed that a prepressure of 30% P_c produced the optimum range expansion of the FBG sensor with a maximum strain measurement of 12,361 με, which was 1.3 times higher than the yield strain of the strands. The analyses of the fatigue performance and static load tests on self-sensing steel strands were also carried out. The results indicated that the self-sensing steel strand exhibited good performance after fatigue loading operation of 2 million cycles with a maximum stress of 0.45 σ_b and a stress amplitude of 250 MPa. Moreover, the decrease in the monitoring strain sensitivity of the FBG was calculated to be below 3.5%, whereas the experimental data showed good linearity and repeatability. Therefore, for effective lifetime monitoring of steel strands under fatigue loading, it is suggested that the FBG sensors need to be placed under a certain prepressure before the construction and service of self-sensing steel strand.     

卡尔曼滤波用于低速下PMSM检测转子位置

将卡尔曼滤波理论和高频信号注入法结合起来,利用高频信号注入法检测电机凸极效应跟踪转子位置,设计卡尔曼位置观测器,消除系统噪声和测量噪声的影响,来准确观测低速及零速情况下无位置传感器永磁同步电机的转子位置。通过仿真验证表明,在有系统噪声和测量噪声的情况下,基于卡尔曼位置观测器的脉动高频信号注入法能够有效去除干扰噪声,精确地跟踪转子位置。     

超磁致伸缩执行器自感知机理研究

为了能有效地减小微器件的体积并实现同位控制，提出了超磁致伸缩执行器同时作为执行器和传感器的自感知工作原理. 分析了超磁致伸缩执行器作为双向换能器的自感知物理基础，以此建立了执行器和传感器的能量耦合模型. 根据磁致伸缩材料的压磁方程，并结合励磁线圈的截面积、匝数及磁致伸缩棒的截面积、长度、弹性模量、压磁系数等，推导了感知力和感知速度的计算方法. 提出了利用桥路法在强驱动信号的背景下提取感知信号的方法，在研制的执行器自感知实验系统上，验证了力感知和速度感知方法的有效性     

悬臂梁振动自适应模糊控制及DSP实现

以粘贴压电自感作动器的悬臂梁为研究对象,推导了悬臂梁振动主动控制的压电元传感方程和作动方程的传递函数,给出了压电自感作动器位置配置优化方法,设计了硬件电路以及软件流程.试验结果表明,利用压电自感作动器和模糊自适应控制器可有效地抑制悬臂梁振动.     

一种自感知型电感同步开关能量采集电路

电感同步开关能量采集(SSHI)电路可显著提高压电式振动能量采集装置的工作效率,然而其开关控制需要外接传感器和控制器。为此,文中提出了一种自感知电感同步开关能量采集电路(SS-SSHI),可完全不依赖外部检测和控制设备,仅通过模拟电路即可自动实现SSHI电路开关的自动开闭和电压翻转。本文阐述了SS-SSHI电路的工作原理,分析了SS-SSHI电路工作状态及功率变化。理论和实验研究表明使用SS-SSHI电路能够显著的提高能量采集效率,相比于标准能量采集电路(SEH),最大输出功率可提高99.23%。     

Self-sensing time-domain reflectometry for detection of the bearing failure of a CFRP laminate fastener hole: effect of peeling of the insulator

Carbon-fiber-reinforced polymer (CFRP) composites are used in aerospace and automobile structures. For many CFRP structures, mechanical metallic fasteners are adopted. In internal structures such as a wing box, damage to CFRP structures around the fastener holes is difficult to see. A simple method of finding damage around fastener holes is thus required for CFRP structures. This study applies self-sensing time-domain reflectometry to detect bearing failure around fastener holes of CFRP structures. In a previous paper, the effect of fasteners was minimized when the micro-strip line (MSL) was placed apart from the fasteners. This study numerically and experimentally investigates the peeling of glass-fiber-reinforced polymer (GFRP) insulator. A bearing failure results in embossing at the edge of a fastener hole. The embossing produces a wedge that causes the peeling of GFRP, generating a gap between the GFRP and CFRP. The gap strongly affects the characteristic impedance of the MSL.