Abstract:This paper expounds the concept and basic components of aircraft structural health monitoring, combs out the common monitoring objects from the aspects of monitoring structure and monitoring amount, reviews the typical research results of recent structural health monitoring data processing, mainly including data acquisition and preprocessing, data analysis, and can see that the idea and method of Intelligent Computing are increasingly applied in it; prospects In this paper, the trend of aircraft structural health monitoring in the future towards large-scale on-line engineering application is presented. Three key points are pointed out, which are the development of airborne on-line monitoring system hardware, the development of algorithm and the standardization of the industry. Then, the recent research cases of aircraft structural health monitoring sensor technology are combed, and the cases of emerging algorithm applied to on-line monitoring system are introduced It can provide reference and reference for further promoting the research of aircraft structural health monitoring system.

Abstract:Some microphones are working in high sound pressure from 160 dB to 190 dB.This article states the calibration method of these microphones, including the standing wave tube method, airflow modulation method, piston phone method, impulse method, shock tube method. Advantages and disadvantages of these methods are compared, progresses of airborne high sound pressure calibration are proposed based on progress of airborne high sound pressure calibration civil and abroad. These can provide metrology reference to high pressure microphone.

Abstract:Tunable Diode Laser Absorption Spectroscopy (TDLAS) is a non-contact optical measurement method which is widely used in combustion diagnosis and propulsion system development. The selection of the absorption line pairs is the basis and key of gas temperature measurement using TDLAS. In the experiment of scanning wavelength-direct absorption method for measuring the temperature of H2O, the basic principles and implementation steps of spectral line selection are systematically studied, and the quantification of each index in the selection principle is analyzed. Then the absorption lines of water molecules in the range of 7000~7500cm-1 were studied and screened. Finally, the numerical simulations were used to analyze and two line pairs were selected: 7022.7091, 7444.3707 cm-1 and 7185.5962, 7444.3707 cm-1, which provided the basis for the design of TDALS temperature measurement system.

Abstract:Aiming at objectives, requirements, and basic problems in measurements and comparison under different conditions, the characteristics were systematically analyzed and discussed. At the same time, the characteristics of modeling measurements were also analyzed and discussed in detail. A standardized processing scheme is proposed especially for the problems that still exist, such as when the measurement condition, the measurement system and the measurement parameter change, the obtained waveform data of the same measured object has obvious difference. By using several simple combined model methods, the offset, translation, amplitude normalization, and then the modeling method of modeling and characterization, this paper has unified processing of the standardized characterization of waveform measurement results.

Abstract:In order to reduce the demand of traditional desktop virtual experiment system for the site and equipment, and solve the shortage of the illuminance meter metrology instructional resources, a illuminance meter virtual experiment program based on Smart Handheld Devices (SHD) was designed and implemented to meet the teaching needs. This program took SHD as the carrier and adopted MultiGen Creator software for real-time scene modeling. The program, Which had been completed interaction and edit of the established 3D model and scene by C# scripting language, was developed on Unity 3D flat. Finally, it realized the augmented reality function by Vuforia software. The experiment shows that the program optimizes the digital resources and meet the needs of illuminance meter metrology teaching.

Abstract:In order to meet the application and test requirements of linear laser displacement sensor, a field calibration method of pixel equivalent of linear laser displacement sensor based on height block is proposed, in which the pixel equivalent in height direction is calibrated by step height to correct the linear error of pixel equivalent set by the manufacturer; the pixel equivalent in width direction is calibrated by step block combined with the transverse direction of sensor The calculation method of moving displacement is obtained. Considering that the linear laser displacement sensor may have tilt error, the tilt angle is calibrated by the height difference of step block width at different positions, and the height measurement error introduced by the tilt angle is corrected. Experimental results show that the method proposed in this paper can solve the problem of contour discontinuity in multi position measurement of linear laser displacement sensor.

Abstract:Resonant sensor has good repeatability, resolution and stability. All-fiber resonant micro sensor has the advantages of micro-nano structure and optical fiber sensing characteristics. Graphene, as a new material discovered in recent years, has good thermodynamic and mechanical properties and can be used as a sensitive element in resonant sensors. A graphene resonant pressure sensor based on optical fiber F-P structure is presented in this paper. It has the advantages of both micro-mechanical sensor and optical fiber resonator. It has high resonant frequency. It shows good performance in pressure measurement experiment. The maximum pressure sensitivity can reach 2.93 Hz/Pa. It has important application value.

Abstract:Impulse acceleration measurement technology is widely used in military science and technology construction. In view of the requirements and characteristics of modern military impact acceleration sensor measurement, following the trend of localization of military measurement equipment, a portable shock acceleration excitation device is developed, and the technical system of dynamic measurement of military impact acceleration is improved to provide important technical support for military impact measurement in China.

Abstract:This paper attempts to apply confocal laser scanning microscope to the measurement of microvickers hardness indentation, which can not only obtain the three-dimensional shape of indentation, but also solve the problem that indentation less than 20 μm cannot be measured by using the characteristics of high-resolution of confocal measurement method. In this paper, the method，steps and examples of indentation measurement are given. The three-dimensional shape of the indentation can be used to characterize the accumulation of materials around the indenter during the pressing process, which can expand the scale of hardness measurement, and has a positive guiding significance for the next development of hardness measurement.

Abstract:In order to solve the problems of complicated operation, low automation, failure of electronic components and frequent maintenance of EJ II-100 Lever Force Standard Machine, the electrical circuit and control system were upgraded while the mechanical structure of EJ II-100 Lever Force Standard Machine was inspected and repaired. The current mainstream PLC control mode was used to replace the traditional MCU control, and the function and technology of the transformed Force Standard Machine were also improved. The test results show that the working stability and automation control degree of the force standard machine are improved. The experiment proves that the functions and technical indexes of the improved force standard machine meet the design objectives and the requirements of the national verification regulations.

Abstract:In the development of aero-engine, many kinds of tests are needed to verify, and various kinds of parameters need to be measured to show the strict conformity. In the performance test of high pressure compressor, there are nearly all kinds of parameters to be measured, which can be used as an example to analyze the design and implementation of the main instrumentation system and calibration scheme for aero-engine. It will provide a reference for the design and implementation of the other aero-engine test rig and similar instrumentation, by summarizing the design process, which including the key points of the instrumentation system, notices in the design, and how to establish a traceability system, and clarify the calibration requirements.

Abstract:Aiming at the stiffness measurement requirements of elastic elements with high accuracy and small deformation, and taking the elastic test of tapered elastic washers in GB/T 94.4 as an example to analyze the problems existing in the domestic universal stiffness measuring instrument when measuring elastic elements with high accuracy and small deformed. Through analysis and experimental verification, and discuss the selection of the displacement measuring device, it is concluded that when designing the stiffness measuring instrument with high accuracy, the cantilever beam loading mechanism and the cantilever beam load measuring device should be avoided. It is proposed a stiffness measuring instrument with high accuracy design scheme that the load measuring device adopts the column force sensor and the displacement measuring device adopts the laser displacement sensor, and the force applying mechanism adopts a double column type .

Abstract:As a non-universal test equipment for aviation model product development, special test equipment needs to be supplemented with corresponding measurement assurance to ensure that the development of special test equipment is synchronized with model product development, and the test data of special test equipment is accurate, reliable and authentic. This article focuses on the whole process of the development of special test equipment, and accurately grasps the measurement assurance characteristics of the special test equipment. The guiding principle of measurement assurance is “incorporating equipment development, strengthening the development process, and focusing on key aspects of control”. This paper systematically sorts out the key tasks of the whole process measurement assurance for the development of special test equipment, and puts forward the rationalization suggestions for the measurement assurance work of special test equipment.

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