非均匀采样莫尔条纹信号的分析与处理

为了动态、实时地测量光电编码器在变速转动情况下的细分误差,提出了一种莫尔条纹信号的非均匀采样分析与处理方法。利用傅里叶级数原理构造了实际情况下的莫尔条纹信号方程,根据编码器在不同转速下的实时采样,揭示了莫尔条纹信号的非均匀采样特征。鉴于信号采样的非均匀性,采用曲线拟合的最小二乘法重构莫尔条纹信号,利用离散傅里叶变换算法分析重构信号并求出波形参数。通过信号参数与细分误差的关系式,测量了编码器动态细分误差。采用该方法对21位绝对式光电编码器莫尔条纹信号进行了分析和处理,两次测试得到其动态细分极值误差为+3.21″、-4.69″和+3.45″、-4.81″。实验结果表明,该方法可以有效地分析和处理编码器在非匀速转动下产生的变频莫尔条纹信号,精确地测量编码器的动态细分误差,为工作现场编码器误差的实时检测与修正奠定了基础。     

莫尔条纹正交偏差的智能补偿方法

提出了一种新的编码器莫尔条纹正交偏差的补偿方法及实现方式。通过比较分析,采用相关函数分析法测量各精码周期莫尔条纹的正交偏差,并基于系统自身的粗码信息,构造一种智能采样算法,保证莫尔条纹采样均匀性;在工作中对所有精码周期的莫尔条纹实行数字式实时补偿,并可以通过模式间的切换自适应地更新正交偏差补偿参数,持续地保证补偿的精确性,降低编码器在各种恶劣环境下的误码率。实验结果表明,正交偏差10度以内时,补偿后的信号正交性提高了93%以上,保证了编码器测量精度。     

莫尔条纹信号相位误差补偿

为减小莫尔条纹信号不正交时的正切法细分误差,提出了一种可对任意相位滞后误差进行实时补偿的新算法.在分析了相位不正交对细分精度的影响后,通过对信号过零点的准确采样,计算出余弦信号相位滞后的角度值,进而确定了实际的相位计算公式.根据存在相位滞后信号的极性和幅值信息,对完整的短周期信号进行相位分段补偿,并分析了影响算法实现的各个因素.仿真实验表明,本算法可实现对相位滞后误差的实时补偿,有效降低信号相位不正交对细分精度的影响,使细分误差仅为未补偿误差的10%,极大地提高了莫尔条纹信号细分精度和位移检测精度.     

小型光电编码器细分误差校正方法

为提高小型光电编码器精度,设计了精码莫尔条纹信号细分误差校正方法.首先建立存在直流分量、幅值误差、波形畸变的精码光电信号的波形方程,然后利用牛顿迭代法将两路精码细分信号校正至标准的正弦和余弦信号,最后建立两路信号间的正交性误差模型,通过最小二乘法求解出正交性误差校正参数.运用本文的细分误差校正法对某16位小型绝对式光电编码器进行误差校正处理,经测试,细分误差峰峰值由校正前的160″减小到校正后的48″.实验结果表明:研究的误差校正方法可以有效地减小细分误差、提高编码器精度,对于研制小型化、高精度光电编码器具有重要意义.     

光电轴角编码器光电信号正交性偏差的相量校正方法

高精度光电轴角编码器中的细分是误差的主要来源,而细分误差中莫尔条纹光电信号的正交性偏差影响最大。采用相量校正方法对正交性偏差进行校正,实现电路简单,校正效果十分明显。以正弦信号为基准信号,而将余弦信号分解为0°和90°两个正交分量,0°分量就是产生正交性误差的原因,通过补偿掉该分量,即可基本消除正交性误差。为进一步减小细分误差,通过精密调节,使余弦信号的幅值与正弦信号严格相等,将正弦及其反相信号与余弦信号分别相量相加可得到严格正交的两个新相量,从而消除正交性误差。实验结果表明,经精密相位校正后,正交性偏差从1″降低到0.1″左右。     

莫尔条纹细分中相位误差的软件补偿方法

在实施莫尔条纹细分中,两路信号的相位误差将影响计量光栅的测量位移时的精度。本文从软件的角度详细论述了相位误差的补偿方法,并且通过理论分析与计算,说明利用该方法的补偿效果,进而证明该方法在实际应用中的可行性。     

光通信粗瞄系统莫尔条纹信号正弦性补偿方法

为了保证光通信终端的精确对准,抑制编码器莫尔条纹正弦性偏差引入的细分误差,设计了基于经验模态分解(empir-ical mode decomposition,EMD)的正弦性修正方法。首先,介绍了卫星光通信终端跟瞄系统的组成与工作原理。接着,分析了莫尔条纹正弦偏差给系统带来的细分误差并给出满足工程需求的正弦性阈值。然后,在阐述EMD分解原理的基础上,给出了基于EMD的正弦性修正方法,该方法利用编码器自身粗码信息计算转速,从而确定精码莫尔条纹信号的基波频率值,并采用EMD分解在原始信号中提取与该值相匹配的基波分量。最后,对该方法进行了原理和转速自适应性仿真,并应用到去掉光学滤波镜片后的粗瞄回路编码器中。仿真及实验结果表明:在光通信终端的各工作转速下,修正后的莫尔条纹正弦性均小于0.85%,满足细分要求;修正后的精码译码结果精确,编码器测角精度维持在1″以内,满足终端对准精度的要求。     

高正交关系的莫尔条纹信号

莫尔条纹的电子学细分需要有一对光电正交的莫尔条纹信号。本文叙述了在圆光栅系统中产生裂相误差的四种原因和消除它们的办法。最后,在一台圆分度检验仪上已经得出了优于0.5°裂相误差的结果。     

空间精密位移信号软细分方法研究

为了解决高精度数控装备对位移传感器高分辨力反馈的需求,本文提出通过对空域信号特征的分析,从时空变换理论模型的角度去研究位移测量问题;利用光栅周期性栅线作为等空间位置触发位置采样建立空间序列模型;通过对光栅莫尔条纹信号自适应预测细分模型阶数与系数估计算法完成光栅莫尔条纹信号细分。实验结果证明此方法可以实现光栅莫尔条纹400倍细分,细分精度优于信号周期的±1%。此细分方法利用光栅刻划精度,信号细分精度与光栅信号波形质量无关,在不增加硬件的条件下实现光栅莫尔条纹精密细分,具有重要实际应用价值。     

基于FPGA的光栅莫尔信号正弦性误差补偿电路研制

针对光栅莫尔信号正弦性误差对细分结果造成影响问题,对基于粒子群算法(PSO)的光栅莫尔信号正弦性误差补偿方法展开研究。在量化分析信号正弦性误差引入的细分误差的基础上,对基于PSO算法的正弦性误差补偿方法进行阐述。设计基于FPGA的补偿算法实现电路,对实现过程中的关键问题进行分析并提出解决方案。最终在FPGA电路板上对实际信号进行算法电路有效性验证,结果表明,应用该电路能有效地补偿信号正弦性误差,将信号的细分误差峰峰值由0.7″降低到0.14″。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

基于多目标非支配解提取法的电力系统无功优化

针对传统的电力系统多目标粒子群优化算法采用权重系数法将多目标转化为单目标,从而忽视了各目标函数间的竞争关系这一问题,提出将非支配解提取法运用到电力系统多目标无功优化中,并设定了一套提取规则,以电力系统中的有功网损、电压偏差和电压稳定裕度为目标,使目标在充分竞争的情况下得出Pareto最优解,利用IEEE-14节点系统对多目标非支配解提取法的电力系统无功优化进行了仿真测试。研究结果表明,该算法一次运行可以得出多组非支配解,既有偏向单个目标的解也有兼顾所有目标的解,克服了权重系数法的盲目性和单一性,可使电力决策者根据实际问题选择最优解,具有较好的灵活性与多样性。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.