Abstract:Graphene is a new type of ultrathin material, and the theoretical thickness of single-layer graphene is only 0.335nm. Due to its excellent material and mechanical properties, graphene resonator is promising to be designed with good structure and performance, achieving ultrahigh sensitive vibration measurement. In this paper, research progress of graphene resonant vibration measurement is reviewed, including research status of graphene resonant vibration measurement, experimental research and theoretical analysis of graphene resonator, and other parts. Vibration measurement has wide and vital demand in aeronautics and astronautics, automobile, micro-electronics, architecture and other industries. Therefore, it is of great theoretical significance and practical value to explore and study the micro-nano structure and graphene vibration measurement with ultrahigh sensitivity.

Abstract:Binocular stereoscopic vision technology is a significant research field of computer vision, and its application is becoming more and more extensive, especially in precision measurement field. The core part of the stereo vision is stereo matching. This paper analyzes the main methods and the key algorithms of matching technology from the perspective of stereo matching technology. Based on the primitive matching algorithm, this paper looks forward to the development trend of the technology. By comparing the advantages and disadvantages of each algorithm, we can get a better understanding of the matching technology and provide the theoretical basis for the future application of binocular vision measurement.

Abstract:The flapping wing aircraft is a new concept-based small unmanned aerial vehicle modeled by bird flying. It is distinguished from traditional fixed-wing and rotorcrafts and its lift and thrust forces are provided by flapping wings. The aerodynamic characteristics of the flapping-wing aircraft are tested to explore the generation mechanism of the aerodynamic force of the flapping-wing aircraft in the unsteady flow field environment and the effects of the relevant parameters of the proposed flapping-wing aircraft on the aerodynamic characteristics. With the help of data provided by aerodynamic test, the work of flapping wing flight control and mechanical structural optimization can be improved obviously. This study will play a huge role in promoting the design of flapping wing aircrafts and the control quality improvement.

Abstract:The existing technology of the measurement of normal vector cannot meet the requirements of accuracy and timeliness. The methods of calculating normal vector cannot be applied to surfaces with different curvatures. In this paper, a method of normal vector measurement based on adaptive curvature is proposed by using binocular stereo vision. Firstly, based on the binocular stereo vision, the surface model of the hole point is established in accordance with the features of the variable curvature surface, and the layout method of the projected point is proposed. Then, according to the 3D coordinates of the projected points, the method of calculating normal vector based on the adaptive recognition of curvature is proposed. Finally, the measurement results of the small curvature surface part are compared with the normal vectors measured by CMM, to verify the accuracy of the method in this paper. The experimental results show that the error of the method is 1.6 °. The method can effectively improve the measurement accuracy of normal vector and satisfy the requirements of the in-site measurement of large aerial parts.

Abstract:This paper introduces the measuring device and method for stability testing of accelerometers, and studies and establishes the temperature error model of accelerometers by analyzing the effects of environment factors, including operating temperature of the accelerometer and foundation horizontal inclination, on stability test of accelerometers. In the stability test, the high precision platinum thermal resistance is used to measure the operating temperature, and the earthquake precursory inclinometer is used to monitor foundation horizontal inclination. The measured operating temperature compensates for the coefficients of the model equation and outputs of the accelerometer. The measured foundation horizontal inclination compensates the zero output of the accelerometer.

Abstract:In the firing of rockets and missiles, the accelerometer used to measure the vibration of the launch device may suffer impacts by the high-speed airflow. In order to explore the effects of high-speed airflow on acceleration measurement, this paper introduces the protecting treatment and the measurement results in laboratory and field test. In laboratory test, the compressed air was used to simulate the blowing of the high-speed air flow, and the acceleration signal of a naked accelerometer was compared with that of the shielded accelerometer. With the laboratory and the subsequent field test, it is concluded that the accelerometer under the high-speed air flow must be protected with proper shield devices. The conclusion provides some useful and meaningful references for acceleration measurement under similar circumstances.

Abstract:This paper introduces a suit of scaling model experiment equipment for turbo engine airflow calibration. The scaling model simulates a turbofan engine test cell, including an air inlet part, an inlet air-flow measurement part, and a wind-fan part. The airflow of the equipment is 15 kg/s, and the velocity of flow is up to 100 m/s.

Abstract:In this paper, in-situ calibration technology of six-dimension force measurement units for the low impact docking mechanism (LIDM)docking performance test-bed is studied. According to the working principle of the six-dimension force measurement unit and test structure characteristics of the test-bed, the research of in-situ calibration method for the measurement unit is carried out. The high-precision standard force loading mechanism is designed based on servo motor controller and force transmission mechanism of planetary screw structure, and a six-dimension force measuring tooling with portability, fine tuning and accurate positioning is built to solve the technical difficulties about smooth loading and benchmark consistency for the in-situ calibration. The research and implementation of the in-situ calibration device for the six-dimension force measurement unit can realize the traceability of six-dimension force parameter of LIDM docking performance test-bed.

Abstract:The packaging of solid state microwave power devices is special, so it is necessary to use measuring fixture as the bridge in the measurement process and the conversion of the interfaces for convenience of the testing. In microwave electric parameters test of solid state microwave power devices, the measurement errors caused by measuring fixture cannot be ignored, and this paper studies the measuring fixture and calibration technology of a solid state microwave power device. In this paper, the TRL calibration method is adopted, the error correction function of the vector network analyzer is used to remove the error of measuring fixture, and thus the real performance parameters of the device are obtained. The test data show that it is feasible and effective to calibrate the measurement fixture and remove the error, so that the pure parameters can be obtained by removing the effects of the measuring fixture.

Abstract:Thermo-hygrometer Test Chamber is a special instrument used to simulate the temperature and humidity situation of nature. At present, there is not any relevant verification regulation. This paper is based on the needs of verifying thermo-hygrometer test chambers, studies the correlative national standards, and puts forward the main performance and method of verification and evaluation about temperature of thermo-hygrometer test chambers.

Abstract:Traditional integrated system calibration is performed with single instrument measurement and system function checks, and the performance and technical specification of the system are not guaranteed. The overall calibration of radar RF test system is an urgent problem at present. Standardized and generalized standard parts for in-situ transfer are designed and assembled, that is, with assemble of sheet transfer standard parts and portfolio transfer standard parts, this paper establishes a working standard for radio parameters as power, amplitude, phase, noise and reflection coefficient and etc. corresponding to the Radar RF test system. By analyzing and evaluating the uncertainty and checking repetition and stability of the above parameters, it resolves value transfer problem for radar RF test system and realizes local integral calibration.

Abstract:The automatic identification of the pointer type meters provides an effective technical method for the real-time monitoring and information management of the shipboard equipment. In this paper, the method of automatic reading of pointer type dials is studied by using visual technology. In order to realize the recognition of many kinds of meters, the recognition process is divided into several parts, such as the dial partition, the scale identification, the pointer recognition and the type identification. The central projection and atlas classification comparison are used, to determine the dial pointer position and the meter category. And the automatic identification of pointer type meters is realized. Finally, the effectiveness of the method is verified by experiments and error analysis.

Abstract:A variety of small resistance measurement methods are studied in this paper and improvement suggestions are proposed to solve the problems and interferences in measurement, and the lack of methods. A small resistance measurement device based on the four-line method is adopted to avoid the effects of the feeding line, the temperature and the auxiliary elements on the measurement precision, so as to improve the measurement accuracy of the small resistances. According to the experimental data, it can be directly found that the measurement errors are reduced, and it is verified that the improvement has practical significance on accurate testing of small resistances.

Abstract:The instrument for determination of fluorine and chlorine in coal and other combustible matter is used for heat-engine plants, coal mine, steel mills and petroleum and chemical industry. Until now the instrument for determination of fluorine and chlorine has not had relevant verification regulations or calibration specifications. This paper proposed easy and reliable calibration methods according to the apparatus structure and operational principle, calibrating the temperature control performance and measurement performance. And the calibration results have favorable traceability and comparability.

Abstract:It is a major way to determine the working zone of a heat treatment furnace for understanding the heat treatment furnace performance. At present there are different technical specifications on the determination methods in China. After understanding the relation between time and temperature parameters in the determination of the working zone, we can be familiar with these specifications, better in understanding and grasping the specifications, able to use the specifications flexibly in practical work, and understand the significance of the test about the working zone.