Abstract:Some different ways to express the environment conditions are summarized, including the natural environment, artificial environment, physical environment, chemical environment etc. Four elements of metrology and calibration environment, namely the environment medium, environment field, environment mechanics conditions, and environment space are presented out to standardize and construct a complex environment. The main environmental element classification method is proposed, and the subsequent elements are listed in descending according to their importance in describing the complex and changing environmental conditions. The strategy to the complex environment influences in metrology and calibration are summarized, including the technique upgrade, local environment control, and environmental factor dimension reduction etc.

Abstract:On the basis of collecting, collating and studying the overall situation of the overseas aviation engine measurement traceability system, this paper mainly introduces the top-level design of the overseas measurement traceability system and the general situation of the construction of relevant standard specification system. Taking the value traceability system of famous foreign aero-engine companies as an example, this paper expounds the advanced and completeness of the foreign aviation engine metering system. This paper provides reference for the construction of the parameter measurement system of aviation engine in China.

Abstract:In order to improve the sensitivity and precision of ultrasonic testing and optimize the parameters of detecting process, it is important to fully understand the sound field formed by ultrasonic transducer. A laser visualization experimental platform for ultrasonic transducer sound field was set up. Using an ultrasonic transducer to emit ultrasonic wave in the specimen, we used laser speckle to receive the displacement of a point on the specimen surface over a period of time, and then obtained the displacements of particles in a certain area by scanning. Thereby a multi-time particle displacement field was formed to achieve the dynamic display of ultrasonic field. The diffusion of sound field of an ultrasonic transducer was detected by the system, and the detection results are consistent with theoretical calculations.

Abstract:In order to study the functions of probe including probing, recognizing and tracking the moving objects on the ground，a simulation system of ground moving device was built. The system realized the high-speed and high-precision motion control of the ground moving device through wireless control. According to the needs of the system functions, a battery driven high speed ground motion device, a 700-meter-long high precision seamless circular track, and a wireless control system are designed，and the track change device, sensors and protection device are configured to build a complete simulation system.

Abstract:The paper presents the application of the pressure pipeline in dynamic tests, analyses the dynamic characteristics in theory, and studies the influence of the temperature to the amplitude response. The frequency sweep tests were performed using the sinusoidal dynamic calibration device on a pressure measurement system with pressure pipeline at different temperatures to verify the temperature influences on the dynamic characteristics of the pressure measurement system with pressure pipeline.

Abstract:As an important component of the impulse force generator, the hammer mass block plays a vital role in the force applying of the dynamic force sensor during dynamic force calibration. The design and improvement of the hammer mass block are described and verified in this paper. The data verification shows that the design is reasonable and satisfies the calibration requirements of the dynamic force sensor.

Abstract:Based on the method of three-flat testing, the comparison of flatness measurements by two kinds of instruments which are isoclinic interferometer and phase shift interferometer was given. With the study of the principles of two kinds of interferometers, a standard process was put forward to extract a few figures from the lattice data tested by phase shift interferometer to fit the data format from isoclinic interferometer. Compared to the structure and environmental control method of isoclinic interferometer, the temperature, temperature gradient and temperature stratification during the absolute measurement of flatness using the phase-shifting interferometer were researched, and the double insulation structure of the cavity of phase-shifting interferometer was applied. The measurement repeatability was 0.002 um, and the uncertainty of absolute measurement was 0.01 um. , The difference from the measurement result of isoclinic interferometer was less than 0.01 um，which illustrates the feasibility of the phase-shifting interferometer used for the flatness verification.

Abstract:Aimed at the problems of that the present pressure sensors can not adapt high pressure testing in high pressure、high temperature and high impact environment, a transient ultra-high pressure piezoresistive sensor was provided. The sensor works with the Wheatstone half bridge principle, and uses the well-piezoresistive alloy manufactured by SiGeMnCu as the sensing element material. By improving the production process and assembly method, the sensor can realize 0～800MPa dynamic pressure testing in transient high pressure and high temperature environment. The comparative analysis shows that the nonlinear error of the sensor is not greater than 0.5% at the high, low and normal temperature. The sensor has the advantages of high sensitivity, small volume and flexible installation. It can be widely used in the pressure testing and research of high pressure gun and airtight exploder device.

Abstract:Battery performance test uses DC discharge test method commonly. The DC discharge test load used in this method has certain requirements for the battery configurations, so it lacks versatility. This paper presents a battery performance test method of UPS based on AC discharge by utilizing the characteristics of UPS to output AC power. The principle of this method is analyzed in detail and experiments are carried out. This method can be applied to UPS battery performance test under different battery configurations and it has better economical efficiency and versatility.

Abstract:：In this paper, the principle of distortion spectrum signal generation of the calibration device for the aircraft DC power supply characteristic testing system is introduced. According to JJF 1059-1999 "Measurement Uncertainty Evaluation and Representation", the uncertainty sources of the DC voltage distortion spectrum of the calibration system for the DC power supply characteristic testing device were analyzed, and the uncertainty evaluation method was given. Finally, according to the above-mentioned uncertainty evaluation method, the uncertainty of the DC voltage distortion spectrum of the DC power supply characteristic calibration device was evaluated.

Abstract:In order to solve the problem that the repetitive test results of the accelerometer scale factor have a 10-5mA/g error in the production process, the accelerometer’s static rolling four-point test in the gravity field is performed. Using the principle of accelerometer test system, the accelerometer scale factor is tested and calculated, and the measurement uncertainty of scale factor is studied. The measurement error source that affects the accelerometer scale factor is found.

Abstract:UDP protocol is the main transmission protocol used in airborne test system for data transmission during flight test. Compared with the TCP protocol, the main feature of UDP protocol is that it is a connectionless oriented protocol, which has low network overhead and fast transmission speed. But the transmission is not reliable, and the data packet may be lost and out of order. Since flight test data processing must take into account the time correlation of data, the flight data processing software needs to develop an appropriate buffer to reorder the data in time. According to the periodicity of network packet time label in flight test, the formula for determining the buffer area size is given, and the rearrangement algorithm of buffer in the case of packet loss and disorder is discussed. Finally, the processing result of real flight test data shows the successful application of the algorithm.

Abstract:Python is an interactive high-level scripting language with simple syntax and high development efficiency. But Python does not support memory pointers, and is not convenient for instrument programming. This paper introduces and compares several methods to invoke instrument driver in Python, and takes ADLINK PXI-nuDAQ2206 multi-function data acquisition card as an example to show how to wrap customized instrument driver into Python’s extension module utilizing SWIG (Simple Wrapper and Interface Generator). Remote and cross-platform API calling is also achieved in the process. Finally, a performance comparison test is designed, and the efficiency of invoking instrument driver in Python is quantitatively analyzed.

Abstract:Under the background of national scientific and technological innovation and high-speed development of digital design and manufacture, the contradiction between advanced digital manufacturing and the traditional metrological assurance mode of "first manufacturing, then testing, and then calibrating for inspection" is increasingly prominent. In this paper, taking the digital metrology guarantee capacity of geometric parameter as an example, by analyzing and comparing the current situation of geometrical metrology guarantee status in aviation digital design and manufacturing projects at home and abroad, it is proposed that in order to ensure the geometric dimension accuracy of the digital manufacturing of products in the whole life cycle of aircraft, the new digital metrology guarantee system should be studied and discussed following the new product geometric specifications, starting from the definition of digital model of products and according to the measurement traceability requirements of key processes and key parameters for digital design and manufacturing collaboration.