A calibration method for the energy-integrating function in photovoltaic system monitoring

Solar radiation has an irregularly varying factor due to a basic day and night cycle and climatic conditions. For such conditions a data sampling interval is important to ensure the accuracy of energy monitoring in a photovoltaic system. While treating a system monitoring equipment as a black box. the author has developed the method of calibrating an energy-integrating function. At first for various input waveforms, the relationship between sampling intervals and quasi-integration outputs have been examined by trapezoidal rule. In the numerical simulation the phases of the sampling clock also are considered Then it is concluded that a sampling interval can be inspected through outside observation only by using a rectangular single pulse. By applying the pulse to the energy-integrating process, two kinds of integrated outputs can be obtained for different sampling phases. The calculated difference between both outputs can uniquely give the sampling interval being inspected. Conditions to ensure measuring accuracy are discussed and the validity of this method has been demonstrated experimentally. Practical calibrating procedures also are proposed for the integrating function of PV system monitoring.     

A three-dimensional measurement system for robot applications

This paper presents a 3D noncontacting sensor system designed to measure the position and orientation of a robot end effector. This measurement system includes two parts: a tridimensional object including four spheres placed along the axes of a tetrahedron and a set of three orthogonally pointed cameras. The purpose is to design a measurement system characterized by easy relationships in order to satisfy real-time constraints. The system has been used in two experiments: first, to calibrate a parallel robot and validate the geometrical control performance, then as an exteroceptive sensor in an assembly task. The system computes position and orientation of the tetrahedron in 100 ms time. The position and orientation accuracy are, respectively, 0.6 mm and 0.2 deg in a workspace, being a cube with 0.3 m sides.     

集成电路测试系统中波形数字化仪的校准研究

文章介绍了波形数字化仪的原理、结构、工作方式及特点,并针对其校准技术进行了深入的研究。通过多功能校准源、示波器及测试系统数字模块实现波形数字化仪模块的精确校准,解决了波形数字化仪模块的校准问题。校准结果表明,该校准装置及校准方法能够满足集成电路测试系统任意波形发生器的校准要求。     

天车称重系统解析

以河北钢铁集团唐山钢铁有限责任公司一钢轧厂240t天车称重系统为例,介绍天车称重系统的硬件结构、工作原理、传输方式、仪表功能、称重传感器原理、钢丝绳补偿、信号传输、称重仪表等,结合在生产中的实际运行状况,总结出在生产维护中的常见问题,并提出具体的解决方法。     

S7-1200利用高速脉冲输出方式实现打印

本文介绍SIEMENS S7-1200利用高数脉冲（Pulse Train Output,PTO）功能与MCU进行通讯的方法,具体介绍其中的一个应用：用PTO实现S7-1200的字符打印输出。     

数字磁通门传感器的自动相位对准

三轴数字磁通门传感器信号处理电路的延时(相位延迟)及各轴延时不一致,影响数字滤波器的输出性能。提出了基于加权最小二乘法的互功率谱相位法计算延时的方法,针对该数字滤波器的特性,选择传感器的不同谐波信号对比分析相位延迟计算的精度,并设计了传感器的自动相位对准方法。实验结果表明:该计算方法精确有效,自动相位对准使滤波器输出性能提高25.89%。     

基于激光多普勒测速法的2×106m/s2高冲击校准技术

在高冲击传感器动态性能校准中,实现高量程、宽脉冲激励是目前高冲击校准急需解决的问题。采用速度改变法校准原理,以气炮为激励源,利用激光多普勒测速方法测量砧体运动速度,建立高冲击校准系统。分析碰撞系统的作用原理,提出调整和控制激励脉宽的方法;分析测速误差,提出双光束差动侧向测速方法。实验结果表明:高冲击校准系统校准量程为2×106m/s2,激励脉宽在2×106m/s2时大于100μs,校准冲击灵敏度的扩展不确定度小于5%(k=2)。     

一种NTC热敏电阻校正方程的试验研究

为了校正NTC热敏电阻的校正方程,提高测温精度。通过对传统的指数方程进行线性变换,得到一种新的NTC热敏电阻温度计R-T特性关系,对此关系进行多阶最小二乘拟合,利用误差评判原理,确定最适合的NTC热敏电阻的校正方程。并且实际验证了此校正方程的测温精度可以满足更高精度要求的需要。     

灰色理论的位移传感器标定不确定度评定

硅晶元等高精度平面度测量时,为提高测量可信性,对所用位移传感器标定已成为业界常规。本研究针对用于基于逐次两点法(STPM)测量硅平面的两电容式位移传感器2804/3890 J设计了一种压电陶瓷标定系统,实现其标定间隔达到8nm/1 mV,提高了标定的精确度。建立基于灰色理论的GM(0,2)系统数学模型,确立待标定传感器测量结果的回归模型,以得到传感器特性的最佳估计,并确定其联合不确定度,得到被标传感器的测量不确定度的最佳评估。与传统回归模型比较,得出GM(0,2)模型具有很好的精度,满足要求。通过STPM测量过程的模拟,得到用此传感器实施的STPM测量的测量精度约为56 nm(λ=20 nm)。