基于预测误差法的加速度传感器动态模型参数辨识

加速度传感器动态模型对研究与分析加速度传感器的动态特性与动态误差补偿具有重要作用。针对加速度传感器动态模型的参数辨识,提出了一种基于预测误差法的加速度传感器动态模型参数辨识方法,该方法将加速度传感器的状态空间模型转化为线性带外生输入的自回归滑动平均(ARMAX)模型,获得其最优一步预测输出的表达式,并通过求解加速度传感器最优一步预测输出极小化误差准则函数,实现加速度传感器动态模型参数的最优辨识。实验结果表明,该方法有效地实现了加速度传感器动态模型的参数辨识,所得加速度传感器动态模型具有较高的精度,能描述加速度传感器的动态特性。     

压电加速度传感器测量中的温度补偿设计

为了解决压电加速度传感器易受温度影响的缺点,通过分析其测量原理和温度变化对压电传感器性能的影响,提出了在压电加速度测量系统中加入热敏元件进行温度测量,并利用单片机软件进行自动实时温度补偿的方法。结果表明,实施温度补偿后,提高了压电加速度传感器的工作性能与可靠性。     

压阻式冲击硅微机械加速度传感器的温度补偿

给出了一种压阻式冲击硅微机械加速度传感器的温度补偿与实现方法.该方法采用串并联电阻来补偿加速度传感器的零位温度漂移,采用在电源后串联二极管来补偿加速度传感器的灵敏度温度漂移.具体实现时,采用高低温试验机对加速度传感器的环境温度进行变化,通过检测系统测量出4个压敏电阻在高低温时的电阻值,运用软件计算出补偿电阻值、补偿电阻在桥路中的位置以及串联二极管的数量,并根据计算结果构建出了带温度补偿的传感器检测电路.测试结果表明,这一方法能有效补偿加速度传感器的温度漂移.     

力传感器模型辨识及动态补偿器设计北大核心

力传感器作为测控系统的最前端,其动态特性对测控系统特性有本质影响。为建立有效改善力传感器动态特性的补偿器方法,根据非线性最小二乘法建立了力传感器的动态数学模型,基于零极点配置法设计了力传感器的动态补偿环节。针对以上方法进行了系统辨识实验与动态补偿环节仿真设计。实验与仿真结果表明,非线性最小二乘法能够切合实际地建立非线性系统的辨识模型,零极点配置法所设计的动态补偿环节极大地改善了传感器的动态特性,可以将该补偿方法应用于工程实际当中。     

力传感器模型辨识及动态补偿器设计

力传感器作为测控系统的最前端,其动态特性对测控系统特性有本质影响。为建立有效改善力传感器动态特性的补偿器方法,根据非线性最小二乘法建立了力传感器的动态数学模型,基于零极点配置法设计了力传感器的动态补偿环节。针对以上方法进行了系统辨识实验与动态补偿环节仿真设计。实验与仿真结果表明,非线性最小二乘法能够切合实际地建立非线性系统的辨识模型,零极点配置法所设计的动态补偿环节极大地改善了传感器的动态特性,可以将该补偿方法应用于工程实际当中。     

基于Kalman滤波算法的姿态传感器运动补偿方法研究

为了消除姿态传感器在检测过程中可能会出现随着运动加速度的变化而产生测量误差的现象,提出了基于Kalman滤波算法的姿态传感器加速度补偿方法。详细介绍了传感器工作原理以及运动状态下的误差分析及补偿。该方法通过将姿态传感器在运动过程中出现的角速度进行误差处理,建立传感器运动线性方程,在此基础上,采用Kalman滤波算法,通过对传感器测量输入的姿态角进行修正,从而达到姿态角准确测量的目的。通过实验数据及仿真分析表明,经过Kalman滤波算法对姿态传感器的运动进行误差补偿后的运动特性输出精度,相比补偿前有了很明显的提高,达到所需精度要求。     

加速度传感器壳体结构的动力学特性分析

针对壳体结构的动力学特性限制加速度传感器动态工作性能的问题,对一种大gn值、高频响加速度传感器的壳体结构进行了动力学特性分析。在振动理论基础上,应用有限元分析软件ANSYS对壳体进行了动力学仿真分析,并利用振动台试验装置进行验证,结果表明壳体的固有频率低于传感器的上限工作频率。据此对壳体结构进行改进,使其动力学特性得到明显改善,提高了加速度传感器的动态特性。     

基于最小二乘支持向量机的传感器非线性动态补偿

提出了一种基于最小二乘支持向量机的非线性传感器动态测量误差的校正方法，使得通过该方法补偿的传感器具有理想的输入输出特性。先将传感器的非线性动态系统分解成线性动态子环节和非线性静态子环节串联；与之对应，非线性动态补偿过程也包含2个阶段：线性动态补偿和非线性静态校正。然后，通过函数展开将补偿器的非线性传递函数转换为等价的类线性形式一中间模型；再通过LS-SVM回归算法求取中间模型参数；最后，推导出中间模型参数与补偿器2个子模型参数之间的关系，并通过该关系实现非线性静态校正和线性动态补偿环节的同时辨识。与常规非线性动态补偿方法比较，该方法优点是明显的：（1）只需进行一次动态标定实验；（2）能给出非线性动态补偿器的数学解析表达式；（3）充分利用LS—SVM的优点，使辨识的补偿器具有更好的抗干扰能力。仿真与实际实验结果均表明该传感器非线性动态补偿方法有效。     

轴承组件各零部件固有频率测试及方法研究

卫星动量轮轴承组件的多数零件重量在10～50g之间，最小的不足2g，给动态测试带来了困难。根据各零件特点，用共振法、锤击法对其进行动态测试。分别用加速度传感器和动态应变仪接收响应信号，进行了幅频特性分析、功率谱分析和传递函数分析，确定了各零件的固有频率。     

基于微粒群算法优化的微硅加速度传感器动态补偿研究

本文提出了一种基于微粒群（PSO）算法优化的微硅加速度传感器动态误差补偿器的设计方法。该方法无需事先已知微硅加速度传感器的动态特性，可根据传感器以及参考模型对输入激励响应的实测数据，通过PSO算法的优化学习得到补偿器的参数。传感器的输出经过补偿器后，能够克服由动态特性引起的测量误差。最后，通过实验验证了该方法的有效性。     

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.     

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。     

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。     

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...     

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.     

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。     

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%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.