Abstract:Micro turbine engine has the advantages of light weight, small scale, high power density and no need of charging. It is the best choice of power source for micro mechanical equipment and has a good application prospect. The rotor diameter of micro turbine engine is in the range of more than 10 mm to dozens of mm. The design speed is generally from hundreds of thousands to more than one million rpm, and the power density target is within 100 W. The friction and lubrication problems of ultra-high speed micro bearing rotor system are the bottleneck of micro turbine engine. At present, gas lubricated bearings are mostly used in micro turbine engines. In this paper, the research status of micro turbine engine is classified and summarized, and the research results of gas bearing test system are reviewed, and the development trend of test technology is prospected.

Abstract:Laser Doppler frequency shift is not sensitive to internal vibration, which makes 3D laser Doppler vibration measurement a difficult problem. To solve this problem, various research institutions have carried out relevant research and put forward several solutions. In this paper, four methods of 3D laser Doppler vibration measurement based on different principles are introduced, including three-dimensional vibration measurement method based on multiple optical heads, three-dimensional vibration measurement method based on one LSV, three-dimensional vibration measurement method combined with stroboscopic method, and three-dimensional vibration measurement method based on single optical head. The advantages and disadvantages of each method and its practical application effect are summarized and prospected The future development direction of 3D laser Doppler vibration measurement technology.

Abstract:Atomic interference gravimeter is a new instrument to measure the acceleration of gravity. Vibration noise will affect the measurement accuracy of atomic interference gravimeter to a great extent. In order to realize high precision measurement of gravity acceleration, vibration and noise must be controlled. The vibration isolation requirements of atomic interference gravimeter are analyzed, and the research progress of vibration isolation system of atomic interference gravimeter is described. Three vibration isolation methods, which are driven by voice coil motor, piezoelectric ceramic and vibration compensation, are introduced. The characteristics and applicable scenarios of each vibration isolation method are summarized, and the prospect of atomic interference gravimeter is proposed The future development direction of vibration isolation technology.

Abstract:Aiming at the problems of many existing point cloud registration algorithms, such as different registration speed and registration accuracy, this paper proposes a registration algorithm combining DNSS with Point-to-Plane ICP. It uses DNSS to extract the key points of the source point cloud data, uses the key point constraints to find the corresponding matching point pairs, and calculates the optimal rigid body transformation matrix combined with the point to plane error measurement method, so as to complete the point Cloud registration. The experimental results show that the registration accuracy of point cloud registration algorithm based on DNSSand Point-to-Plane ICP is higher than that of point-to-point ICP algorithm and Point-to-Plane ICP algorithm, and this method has significant advantages in processing point cloud data with complex geometric features and obvious features.

Abstract:We present a heterodyne optical phase-lock loop system for atom interferometers. The frequency and phase synchronization of two external cavity semiconductor lasers are realized. The laser beat signal linewidth is less than 1 Hz, the residual phase noise within 10 MHz integral bandwidth is 0.002 rad2, and the phase noise reaches a flat floor of ?100 dBc/Hz in the offset frequency range of 1kHz to 100kHz. We researched the impact on the sensitivity of the atomic measurement. Using the 200ms’ interrogation time, the 30μs’ π Raman pulse duration time and the 1s’ cycle time, we calculated that our system would allow us to reach a sensitivity to acceleration as low as 10μGal?Hz-1/2.

Abstract:At present, the calibration method of laser centering instrument is mainly based on the cushion gauge block method, but this method has the disadvantages of complex operation, low efficiency and low reliability. In this paper, a fast calibration method of laser centering instrument is proposed, which integrates beam alignment and two-dimensional positioning error calibration, and develops the corresponding calibration device. The device uses the laser head holder to install the measured unit of the centering instrument, uses the grating type two-dimensional mobile platform to change the position of the measured unit, installs and adjusts the reference unit of the centering instrument through the three-dimensional zero return offset turntable, and uses the self-developed grating digital display meter to observe and display the X-axis and Y-axis position and status information in real-time. The measurement range of the device is 40 mm auge block methe expanded uncertainty of measurement is 3.2 μm. Iit has the advantages of high accuracy, convenient operation and good reliability. It has practical application value and technical reference significance. To solve the calibration problem of the laser alignment device, a rapid calibration method for the laser alignment device is proposed, which combines beam alignment and two-dimensional positioning error calibration. A laser alignment device has also been developed, which has a measurement range of 40mm x 40mm and an extended measurement uncertainty of 3.2μm.

Abstract:Through the investigation of the pressure measurement system of the ground tester of the aviation electromechanical hydraulic, environmental control, fuel oil and other professional products, the existing problems of the measurability are found. In this paper, the measurability problems of the pressure measurement system of the ground tester of the aviation electromechanical products are divided into unreasonable technical indicators, unreasonable selection of measuring instruments, reasonable pipeline design and unreasonable layout of the tester. Four aspects are introduced in detail one by one. Finally, three suggestions are put forward to improve the measurability of the pressure measurement system of the ground tester of the aviation electromechanical products.

Abstract:Trough the indoor testbed of an engine numerical simulation research , the characteristics of the entire flow field was obtained .We analyzed the physical quantities such as velocity ,static pressure and drawn the entire flow line .Aiming at the modification method of aerodynamic additional drag section method in the indoor testbed ,the velocity and static pressure variation law under different sections are studied ,which provides the basis for the measurement of the measurement points of aerodynamic additional drag section method in the actual test. The measurement and calculation results are obtained through the actual test of a certain engine. The results show that the numerical simulation can clearly simulate the whole field conditions during the test, and obtained the measured inconvenient data. It can supplement the inconvenient measuring positions in the indoor testbed, and obtain the layout of measuring points based on the simulation to meet the requirements of measurement and calculation.

Abstract:Rhodium is widely used in automotive catalysts, gas sensors, biomedical, chemical industry and etc. While its purity will directly affect the performance of the product, therefore , the accurate determination of the content of impurities in rhodium is of great importance. At present, the commonly used detection methods are inductively coupled plasma emission spectrometry (ICP-AES) and glow discharge mass spectrometry (GDMS). The data obtained by the two detection methods are compared with the Six Sigma statistical method, and the cause analysis and improvement of the significant different results are carried out.

Abstract:Taking metrology technology as core, this paper explores the conformity assessment procedure applicable to the measuring instruments in China, integrate metrology technology into the quality formation process of measuring instrument products, give full play to the evaluation and guarantee role of metrology in various technical activities of research and production of measuring instruments, improve the overall supply level of measuring instruments in industrial enterprises， innovate industry measurement cross domain collaboration, and promote the integrated development of national quality infrastructure.

Abstract:In view of the shortcomings in the development and use of aerospace product test and measurement software, such as weak pertinence, low compilation efficiency, generality, operability and poor maintainability, this paper studies the advantages of current software engineering and compilation standards of aerospace product test software, makes in-depth exploration and Research on seven aspects of measurement software development, such as characteristic demand analysis, system design, module design, etc, formulates corresponding solutions, compiles the engineering management method for military product model test and measurement software of our unit and applies it to the development of pressure sensor / transmitter verification software, which has achieved good results through verification.

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