Previous review:Development trend of digital geometric measurement technology
The measurement we often discuss at present is generally carried out for a certain characteristic and index. However, with the development of measurement technology, the demands for process oriented online detection, application-oriented performance comprehensive testing, and product life cycle monitoring are also emerging day by day, which has become a new trend, greatly expanding the object and scope of measurement. At the same time, it also puts forward new requirements for measurement technology and the integrated application of measurement technology, which is a challenge to the measurement community.
In order to meet the challenges, in recent years, the digitization, automation and systematization level of the measurement technology itself has also been continuously improved. At the same time, a large number of technical specifications and operating procedures have been revised and formulated, thus fundamentally ensuring the reliability of the measurement data.
With the advancement of digitalization, what role will measurement play?
When discussing the digital transformation today, we will all talk about the concept of digital twin. International ISO gives the definition of digital twinning in ISO 23247-1:2021 digital twinning architecture for automation systems and integrated manufacturing systems Part 1:overview and general principles:
< Manufacturing system > A digital representation of observable elements of a manufacturing system that meet the requirements and have synchronous characteristics.(Note:Translated by the author)
Here, the observable manufacturing element (OME) of the manufacturing system refers to the observable physical existence and operation contents in the manufacturing system, including people, equipment, materials, processes, facilities, environment, products, and supporting documents.
从ISODigital twin的定义中我们可以看到Digital twin的核心在于实体和对象相关特征属性与其数字表达之间的同步，以及实时性。在这个数字环境的表达过程中，实体方面特征参数的获取就是靠测量来实现的。换句话说，没有测量就没有ISO标准中所定义的Digital twin。
面对Digital twin的同步表达要求，其对测量操作要求就不仅是精准、还有实时的要求，因为Digital twin另一个特点是需要在实时精准数据基础上完成实时的控制和互动。在这种情况下，Thus, higher requirements for measurement operation are formed:
1. the accuracy and credibility of measurement data is the foundation of measurement. Meanwhile, standardizing and controlling measurement operation is the core. It requires operators to pay attention to the impact of human, machine, material, environment and method, control these impacts through standardized operation, and evaluate and control the ability of measurement system through digital means such as measurement uncertainty estimation, so as to ensure the reliability of measurement data and support the delivery of data. With the digital expression requirements of real-time, synchronous and full life cycle, the control requirements for the capability of the measurement system will inevitably be extended to these scenarios;
2. when the measurement operation goes out of the laboratory, integrates into the system and equipment, integrates into the production site, and carries out high-precision collection of dynamic data in real time, the massive data will inevitably put forward new requirements for edge computing, Internet-based data processing and data management;
3. 对测量操作而言有一个最基本的对偶原则，即必须正确响应前端设计给出的要求，并按规范进行测量操作。换句话说，测什么是由前端设计给出的。因此，要真正形成Digital twin的数字表达，其被测对象和要素的定义将是关键，在这个定义过程中，就必然会要求测量介入前端，以配合前端被测要素定义时的可测性分析，以及测量结果的表达形式、处理操作、集成方法和管理方法；
4. when the elements are represented by numbers, even after the measurement data of the attributes of the elements of the whole system are available, there will be a need to carry out deeper data association, so as to more accurately describe the twin model. At this time, big data tools will be useful. Of course, who does this work is a problem, but when the data of the system is in the hands of measurement, measurement can also do some data processing, such as edge calculation Correlation analysis and in-depth observation from different perspectives;
From the above discussion and analysis, we can see that in addition to its own professionalism, the measurement technology in the digital age will also be endowed with the characteristics of synchronization and systematicness by the digital age,Here, we need to focus on the following aspects:
1. the application of measurement technology has newer and higher requirements in measuring (the diversity and complexity of the measured object), measuring quickly (the dynamics and real-time of the measured object), measuring accurately (the high-precision measurement of technical parameters under various scales), measuring economically (the economy of the system angle), measuring completely (the full digital expression of the measured object), etc;
2. the omni-directional, multi parameter synchronous measurement, data fusion and edge computing capabilities based on the Internet/Internet of things have become a new feature of modern digital measurement, and will promote the development of measurement sensors, instruments and systems;
3. the center of gravity of measurement operation will be moved forward on the original basis. Especially when the front end uses model-based definition (MBD) technology to transmit measurement requirements and drive the back end, the degree of automation of measurement operation will be higher and higher. It is worth noting that this trend does not simply eliminate the first-line measurement operators and replace them with machines, but puts forward higher requirements for measurement practitioners and the industry, It further requires the measurement practitioners to have the abilities of measurement feasibility analysis, measurement specification design, automatic measurement operation conversion and system construction, digital evaluation of measurement capability, measurement data analysis and collaborative management on the basis of adhering to the original measurement operation professionalism. For the measurement industry, it puts forward higher requirements for digital transformation.
As a basic technology, measurement is not only indispensable in the digital transformation, but also plays an indispensable role in the carbon trajectory, carbon emissions and carbon trading activities in the dual carbon initiative actively initiated by the United Nations and our country, because in the whole dual carbon process, all decision-making data rely on the basic data obtained from the first-line measurement. In other words, only with strong measurement technologies and capabilities, especially the support of the basic platform, can there be double carbon, green and sustainable development.
Because of the importance of measurement, the United Nations lists it as one of the three elements of the national quality infrastructure (nqi). In addition, in 2021, the State Council issued the measurement development plan (2021-2035), which clearly proposed to preliminarily establish a”national modern advanced measurement system” by 2025.
In short, measurement will play a more important role in the digitalization of the whole country and the transformation and upgrading of manufacturing industry, and the value of measurement will become more and more important and will be released.
Li Ming, Professor/doctoral advisor, School of mechanical and electrical engineering and automation, Shanghai University.[email protected]
Weiqingyue, experimenter, School of mechanical and electrical engineering and automation, Shanghai University