Precision Testing Technology Outlook
The development of advanced technologies is changing with each passing day, and precision testing techniques should adapt to this development. The role of precision testing technology in the discipline of machinery is to serve the advanced manufacturing industry and to assume the responsibility of quality and technical assurance. This requires that the first step is to improve the quality of the product. This is the most important goal to be achieved. Followed by precision testing technology to improve product production efficiency. Therefore, the detection method must be able to adapt to the requirements of rapid development of production, not only for testing, but also not because of the requirements of the inspection and affect the efficiency of production. From a more positive point of view, it should be promoted by the good service of precision testing technology. Increased production capacity. According to the requirements of the development of advanced manufacturing technology and the development laws of precision testing technology, new measurement principles and test methods, as well as test information processing technologies, are constantly being developed. In terms of mechanical disciplines, the following aspects are expected to be developed.
1. Measurement and Control in Zero Waste Production
In manufacturing, the ideal goal of quality assurance is to implement zero-waste manufacturing. In the process of achieving this goal, the role and significance of precision testing technology is self-evident. The processing quality of parts and components and the assembly quality of the complete machine are related to the analysis and processing of processing equipment, test equipment, and test information. Therefore, to achieve zero waste product production, the following issues should be considered in view of the precision test: (1) Before machining the workpiece, check the machine in advance. How to quickly and accurately calibrate the processing equipment and obtain the accuracy of the machine tool is very helpful for greatly reducing rework and even eliminating rework. Of course this is research and development involving testing equipment. (2) During the production process, online measurement of the workpiece or 100% inspection of the workpiece is required. This requires the study of test equipment that is suitable for dynamic or quasi-dynamic testing, and even special test equipment that can be integrated into the processing equipment to achieve real-time testing. According to the test results, the process parameters are continuously modified to supplement the processing equipment or feedback control. From the aspect of precision theory, we must also study the dynamic accuracy theory, including the assessment of dynamic accuracy. (3) Study how to make full use of measurement information to achieve zero waste production. Through the full use of 100% online measurement data, the dynamic characteristics of error distribution in the process of machining and measurement are analyzed, and at the same time, based on the dynamic characteristics of the machining error and precision loss characteristics of the sensor accuracy, as well as product quality requirements and tolerance regulations, zero waste products are provided. The basic theoretical model of manufacturing. Make full use of artificial neural networks, genetic algorithms and other modern mathematical methods to accurately predict the quality of processing, so that the quality of advance control.
2, visual testing technology
There are many non-contact test technologies, and it is especially worth mentioning that visual test technology. The development of modern vision theory and technology not only lies in simulating the functions that the human eye can accomplish, but more importantly it can accomplish tasks that the human eye cannot do. Therefore, as the latest technology in today's world, vision technology is continuously developed in electronic, optical and computer technologies. It has developed rapidly on the basis of maturity and perfection. Visual testing technology is an emerging testing technology based on computer vision research. Different from the visual pattern recognition and visual comprehension of computer vision research, the visual test technology focuses on the geometric dimensions of the object and the position measurement of the object, such as the measurement of the three-dimensional shape of the car body in white, the rapid measurement of the three-dimensional shape of the mold, and large workpieces. Coaxiality measurement, coplanarity measurement, etc. It can be widely applied to active and real-time measurement processes such as on-line measurement and reverse engineering. Visual testing technology has developed rapidly in foreign countries. As early as the 1980s, the US National Bureau of Standards estimated that 90% of inspection tasks will be completed by visual test systems. In the United States in the 1980s, there were more than 100 companies in the market for visual test systems. It can be seen that visual test systems are indeed promising. At the Beijing International Machine Tool Expo in October 1999, we have seen the development of foreign instruments using visual inspection technology, such as mobile optical coordinate measuring machines, high-speed high-precision digital scanning systems, non-contact optical coordinate measuring machines and other advanced instruments. .
3 Measures to Diversify Development
(1) Application of multi-sensor fusion technology in manufacturing sites Multi-sensor fusion is a method to solve measurement information acquisition in the measurement process, which can improve the accuracy of measurement information. Since multi-sensors acquire information in different ways or from different perspectives, information fusion between them can be used to eliminate false memories and improve measurement accuracy.
(2) Block-type, combined measurement method The body-in-white three-dimensional measurement system belongs to this type of method. It can also be said to be a dedicated coordinate measuring machine with good flexibility. The key lies in the establishment of the system.
(3) Portable measuring instruments such as portable optical fiber interferometers, portable large-scale three-dimensional measuring systems, etc. are often used to solve large-scale measurement problems in the field.
(4) The virtual instrument virtual instrument is the application of virtual reality technology in the field of precision testing and has been deeply studied in China. One is to virtualize multiple digital test instruments into a digital intelligent test instrument supported by a computer; the other is to study virtual measurements in virtual manufacturing, such as virtual gauge blocks, virtual coordinate measuring machines, and so on.
(5) Smart structure It belongs to structure detection and fault diagnosis, and it is an interdisciplinary subject that integrates intelligent technology, sensing technology, information technology, bionic technology, materials science, etc., enabling the concept of monitoring to transition to online, dynamic, and active real-time. Monitoring and control.
4, measuring size continues to develop toward the two extremes
The so-called two extremes refer to the large size and small size relative to the current measurement size. The measurement of the usual size has been widely noted, and a variety of test methods have also been developed. In recent years, due to the rapid development of the national economy and the urgent need, the requirements for testing in production and engineering have exceeded the range we can test in many aspects, such as the measurement of aircraft profiles, the measurement of key components of large-scale machinery, and the guide rails of high-rise buildings. Collimation measurement and on-site calibration of tank trucks require large-scale measurements; the rapid development of microelectronics and biotechnology, the exploration of the needs of the microscopic world of materials, and the continuous improvement of measurement accuracy require micrometer and nanometer tests.
(1) Large-scale measurement methods such as engineering geodetic methods refer to the transplantation and improvement of some principles and methods of geodetic surveying to mechanical engineering surveys, the generation of new measurement methods, and other methods for measuring large-scale measurements, such as Laser tracking interferometry three-dimensional measurement system.
(2) From the trend of manufacturing and testing, nanometer test technology requires a one-third reduction in allowable error per decade, and therefore requires higher and higher accuracy of measurement, and can be traced to an international standard (ISO). Of course, there are many kinds of nanometer measurements, such as optical interferometers, quantum interferometers, capacitance micrometers, X-ray interferometers, frequency-following Fabroid gauges, scanning electron microscopes (SEMs), and scanning tunneling microscopes (STMs). Atomic force microscope (AFM), molecular measuring machine M3 (molecular measuring machine), etc.
5, to achieve a variety of traceability requirements
(1) Self-calibration and self-calibration High-precision measurement requires high-precision traceability. In many cases, it is difficult to find instruments that meet the accuracy requirements. The important reason is that traceability restricts the development of measurement accuracy. In some cases, measurement instruments can be used. Calibration and virtual measurement methods to solve the problem of traceability.
(2) Direct on-site calibration More and more measuring instruments require direct on-site calibration. Many are still three-dimensional space calibration. The development of on-site calibration techniques and instruments is the key to accomplish these calibrations. FLIR | UK EDG | UK MICRONICS | UK ION | Switzerland LECOM | Germany DEUTO TESTO | GERMAN METREL | GERMANY WTW | OPST OPUS | OLDHAM OLDHAM | Electronic Hardware Tools | CEM | FISHTEC FAITHTECH | Imported Instruments | Import Tools |
(3) Traceability of nanometric nanometer traceability is also an important issue. In foreign countries, NIST, Germany PTB, and Japan NRIM have studied the crystal plane spacing of silicon (220) crystals. The crystal lattice size is stable at a constant temperature and can be used to establish a benchmark for nanometer traceability.