力值砝码计量校准与其测量不确定度研究

力学计量中静重式力标准机、静重式扭矩标准机或活塞式压力计等都建立在专用砝码载体上,是基于重力作用由质量单位导出的其他物理量单位（如力值“牛顿”、扭矩“牛米”、压力“帕”）。文章分析标准测力杠杆中力值砝码质量标称值如何按使用地重力加速度、空气密度进行计算与其测量不确定评定。这种方法同样适用于扭矩板子检定仪检定装置、活塞式压力计等计量标准中物理量对应专用砝码计量校准。只有确保力值砝码计量准确、可靠,才能提升力值、扭矩、压力、硬度等力学计量标准的准确性。     

标准测力仪方位误差对其使用性能的影响

标准测力仪方位误差是其力值复现性的关键技术指标,它直接影响了标准测力仪使用中的计量性能;由于标准测力仪检定规程对方位误差制定不科学,导致标准测力仪进行材料试验机检定时会引入较大不确定度。     

0.5级力传感器示值误差测量结果的不确定度评定

采用杠杆式测力机标准装置依据JJG 391-2009《力传感器检定规程》测量0.5级力传感器并参考JJF 1059.1-2012《测量不确定度评定与表示》对其测量结果不确定度进行评定。文章探讨了检定力传感器测量结果的不确定度来源,评定过程和方法。     

500kN电动独立加码静重式力标准机砝码加卸驱动问题研究

论述了电动独立加码静重式力标准机的工作原理和结构特点,以所研制的500kN静重式力标准机为例,研究了独立加码方法的运动规律,推导了驱动机构的功率、速度、扭矩的计算公式。500kN静重式力标准机已在中航电测仪器股份有限公司应用运行3年,应用实践表明,所提出的独立加码技术方法是可行的和有效的。独立加码力标准机具有精度高、工作可靠、结构简单、效率极高、测力范围大、自动化程度高和成本低等诸多优点,为力基准机和标准机的发展提供了一种新的理论方法和试验依据。     

对叠加式力标准机现状的一些认识与思考

本文通过对我国现有的各种类型的叠加式力标准机进行考察了解后,从叠加机的结构型式和功能上进行总结和思考,进而对如何保证叠加式力标准机的准确性和可靠性给出一种方法,即在一台叠加式力标准机安装多组高等级标准测力仪,这样不但可以实现一台标准机测量范围的扩大,而且可以通过对比多组标准测力仪的数值来确定仪器的准确性。     

测力称重传感器检测方法的探讨

测力称重传感器通常采用静重式力标准机和比对式力标准机这两种方法进行检测。本文在分析上述两种方法优缺点的基础上，提出一种采用静态仪表实现动态检测的方法。这种方法可以在提高检测速度的同时，保证不降低精度。     

新型静重式力标准机及误差分析

本文介绍了用于称重传感器各项指标检定的新型静重式力标准机的结构特点、误差计算分析及与国家基准机比对测试结果。     

一种静重式力标准机砝码连接结构设计和应用

本文以一次静重式力标准机的改造为例,介绍了一种静重式力标准机的砝码连接方式,重点介绍了此连接方式的结构及使用装配,为静重式力标准机的发展提供了一种新的设计思路。     

机动车检测专用轴(轮)重仪标准测力仪检定的符合性判定

本文依据JJG1014-2006 《机动车检测专用轴(轮)重仪检定规程》,对各不确定度的分量进行分析与评定,按照机动车检测专用轴(轮)重仪的测量模型对其合成标准不确定度进行评定,结合具体数据对各不确定度分量进行计算并得出合成标准不确定度和扩展不确定度。对照JJF 1059.1-2012测量不确定度评定与表示与JJF 1094-2012测量仪器特性评定的要求进行符合性判定。数据表明:该机动车检测专用轴(轮)重仪符合检定要求。对实际机动车检测专用轴(轮)重仪检定具有一定的参考意义。     

标准测力仪长期稳定度分析——以广东计量院某型号传感器为例

标准测力仪被广泛应用于各行各业,其精度对科学测量力影响至关重要。标准测力仪的主要技术指标包括重复性、方位误差、长期稳定度等。本文以广东省计量院某型号传感器为例,通过对2009-2020年12年内的检定测试结果展开计算分析,全面剖析标准测力仪的长期稳定度变化特性,为标准测力仪精准测量提供依据。     

基于图像识别技术的力值在线校准装置

专用生产及检测设备通常无法产生标准力源,因而设备上使用的测力装置很难像材料试验机一样用标准测力仪进行校准;采用图像识别技术,可以将这些专用设备屏幕上显示的图象力值数据转换成可通讯的数字信号,并与计算机进行通讯,从而实现力值逐点在线校准。     

基于惯性修正的铣削力系数辨识

切削力是加工过程中的重要物理现象之一,准确、容易获得的切削力数据对切削过程的理论和实验研究都很有帮助.为获得准确的铣削力系数,提出了基于惯性修正的力补偿方法,消除了测力仪及工件在加工过程中的惯性影响.并通过试验.测定了两种刀具加工2A12铝合金时的铣削力系数,为准确测定切削力以及进行加工过程的稳定性预测奠定了良好基础.     

Development of a dynamometer for measuring individual cutting edge forces in face milling

Cutting force information may be used for several tasks, such as tool design and trajectory optimization, tool condition monitoring, machinability testing and many others. Accordingly, cutting force measuring has become a crucial activity aimed at enhancing process performance. In this work, the development of an innovative rotating dynamometer for cutting force measurement in milling is illustrated. The device is capable of providing independent triaxial cutting force information from each cutting edge with a good dynamic response. Static and dynamic behavior of a simplified single-edge device was first investigated through the static calibration procedure, pulse tests and preliminary cutting tests. Afterwards, the dynamic properties of the final prototype clamped on the spindle of a high speed milling machine were assessed by means of standard and rotating pulse tests – i.e. pulse tests performed during spindle rotation. Eventually, cutting tests were performed on a benchmark workpiece. The experimental tests highlighted the superior features of the new device.     

Detection process approach of tool wear in high speed milling

The cutting tool wear degrades the quality of the product in the manufacturing process, for this reason an on-line monitoring of the cutting tool wear level is very necessary to prevent any deterioration. Unfortunately there is no direct manner to measure the cutting tool wear on-line. Consequently we must adopt an indirect method where wear will be estimated from the measurement of one or more physical parameters appearing during the machining process such as the cutting force, the vibrations, or the acoustic emission, etc. The main objective of this work is to establish a relationship between the acquired signals variation and the tool wear in high speed milling process; so an experimental setup was carried out using a horizontal high speed milling machine. Thus, the cutting forces were measured by means of a dynamometer whereas; the tool wear was measured in an off-line manner using a binocular microscope. Furthermore, we analysed cutting force signatures during milling operation throughout the tool life. This analysis was based on both temporal and frequential signal processing techniques in order to extract the relevant indicators of cutting tool state. Our results have shown that the variation of the variance and the first harmonic amplitudes were linked to the flank wear evolution. These parameters show the best behavior of the tool wear state while providing relevant information of this later.     

基于动态电磁力的主动式动平衡测量方法的研究

动平衡机在测量大质偏类工件时,由于不平衡量较大,振动信号往往会超出测量系统的线性范围而造成测量误差偏大。为了提高动平衡测量精度,提出了一种采用电磁力产生的同频振动抵消大部分初始振动,从而减小簧板振动量,保证系统线性度的动平衡测量方法。讨论了该方法的基本工作原理,建立了电磁力装置的磁路模型;采用有限元建模对电磁力的可控性进行了研究,并分析了气隙、温度等因素对电磁力的影响;最后介绍了测量控制系统和控制策略。动平衡测量实验表明,该测量方法能够有效地提高大不平衡量工件的动平衡测量精度。     

100 kN deadweight force standard machine and Evaluation

A deadweight force standard machine is a mechanical structure that generates force by subjecting deadweights to the local gravitational field. The Korea Research Institute of Standards and Science (KRISS) developed and installed a 100 kN deadweight force standard machine for national force standards. It can generate forces from 2 kN to 110 kN in increments of 1 kN. The uncertainty of the force machine was estimated and declared as 2 × 10⁻⁵. This 100 kN deadweight force machine was compared with the 500 kN deadweight force standard machine at KRISS and the 20 kN and 50 kN deadweight force standard machines at the National Metrology Institute of Japan (NMIJ). The measurement results showed good agreement between the deadweight force machines, and the accuracy level of the 100 kN deadweight force machine was verified.     

基于图象识别技术的全自动力标准机开发研究

通常力标准机只能对具备通讯接口的被测仪器进行自动检测,利用图象处理系统可以将非通讯类测力仪器与力标准机之间建立通讯关系,从而实现普通测力仪器的全自动测试。     

多维测力仪扰力解耦算法研究

多维测力仪各向力之间的干扰是影响测量精度的主要决定因素之一。从测力仪标定数据处理分析的角度，提出了一种基于测力仪标定线性回归直线方程的解耦算法，并用Matlab进行解耦运算。研究结果表明：采用解耦算法，可有效地减小多维测力仪各向之间的扰力误差，提高测力仪的测量精度。     

多维测力仪扰力解耦算法研究

多维测力仪各向力之间的干扰是影响测量精度的主要决定因素之一。从测力仪标定数据处理分析的角度,提出了一种基于测力仪标定线性回归直线方程的解耦算法,并用Matlab进行解耦运算。研究结果表明:采用解耦算法,可有效地减小多维测力仪各向之间的扰力误差,提高测力仪的测量精度。     

Dynamic wireless passive strain measurement in CNC turning using surface acoustic wave sensors

Wireless, passive and dynamic surface acoustic wave (SAW) strain sensors are especially advantageous in applications with harsh environments where complex force measurements are required. High frequency multiple axis force measurement during machining processes typically requires state-of-the-art piezoelectric dynamometer technologies. Integrating dynamometers and their associated measurement chains into the machining environment typically requires significant modification to the machine structure. In this paper, SAW sensors were developed for process monitoring operations. Single-axis continuous and interrupted cutting investigations were carried out using the SAW technology installed on cutting tool holders demonstrating high dynamic bandwidth strain measurement. SAW dual-axis oblique cutting measurements were carried out where four SAW sensors were set up as two differential pairs each measuring a single axis of applied force. Improvements in sensitivity and cross-talk compensation has been realised. High-frequency wireless passive realtime process signals are presented from a passive wireless SAW force measurement system successfully integrated into an LT15 Okuma machining centre. The paper aims to present wireless passive SAW technology as a potentially platform changing approach for process and tool condition monitoring applications in the future.