Jia H.-Z.,Chinese Flight Test Establishment |
Luo Y.-R.,Chinese Flight Test Establishment
Guangdian Gongcheng/Opto-Electronic Engineering | Year: 2010
To get the 6D parameters of an object, two cameras are at least involved in the system to shoot at different positions so that the stereopair with a certain parallax can be obtained, and then the space parameters of the object will be worked out through space intersection. By changing the classical photogrammetric collinearity equations, parameters to be solved are taken as equation parameters to obtain extended collinearity equations. When the rigid object have three or more reference marks of known coordinates, the 6-dimensional space parameters of target can be got by use of single frame images. Because of fewer cameras to be needed, the technique can be applied to the occasions that too many cameras are not allowed to be installed, such as flight testing, aircraft components docking.
Jianying S.,Chinese Flight Test Establishment
28th Congress of the International Council of the Aeronautical Sciences 2012, ICAS 2012 | Year: 2012
Extending the calendar life of airborne products is an urgent problem for aviation maintenance engineering since there are not sophisticated theories and methods. This paper analyzes the existing problems in life control system of airborne products. Based on the reliabilitycentered maintenance (RCM) theory and flight test, then a new method called "Comprehensive Analysis and Decision-making Method for Life Extension" is presented. At last, flight test results are given to illustrate the correctness and effectiveness of the methods. The method makes great contribution to the integrated logistic supportability of the aircraft.
Jiang Q.,Chinese Flight Test Establishment
Beijing Hangkong Hangtian Daxue Xuebao/Journal of Beijing University of Aeronautics and Astronautics | Year: 2013
High sink speed landing was discussed which was used to verify the strength and rigidity and shock-absorbing ability of landing gear in land-based airplane flight test. Sink speed was one of the key factors in landing gear design and verification. In fact, aircraft landing was effected by many factors, so it is very difficult and full of high risk for pilot to manipulate an aircraft to land at sink speed regulated by specifications. Landing and touchdown methods, such as floating-drop and direct-gliding and landing training were put forward and used in flight tests. According to this, the sink rate of a land-based airplane flight test in domestic reached 2.47 m/s, which is the maximum up to now. So the landing gears of this type aircraft satisfy relevant specifications.
Feng W.-Z.,Chinese Flight Test Establishment
Jiliang Xuebao/Acta Metrologica Sinica | Year: 2014
The coolant flow in the aircraft liquid cooling system is usually regarded as an important parameter of the assessment of the system performance. With the aid of utilizing the diameter-variable ducts in the liquid cooling system as a throttling element, the coolant flow can be measured by using the differential pressure method. By applying data fitting to the experimental findings obtained from the groud calibration system, the characteristic curves of the coolant flow versus differential pressure for different temperature and pressure values were obtained. Furthermore, the formulate for the correction of calculated coolant flow were gained through linear interpolation. The flight test results indicate that the method is feasible for the measurement of the coolant flow of the aircraft liquid cooling system and, therefore, the problem of inconvenient refitting of flowmeter for the liquid cooling system has been solved.
Hou H.,Chinese Flight Test Establishment
Guangdian Gongcheng/Opto-Electronic Engineering | Year: 2015
The motion parameters of aircraft and its external store can be obtained by photoelectric theodolite in flight test, but due to large distance measured or target blocked, it's difficult to capture target very fast. After adding GPS receiver on the aircraft, we can get geodetic coordinate in real time. After the real-time acquisition data coded thought the telemetry channel, the ground machine can demodulate coordinate of the aircraft. The PCM data Stream can be received from the airborne transmission stream through the PCM telemetry receiving channel which is integrated on photoelectric theodolite. At the same time, the geodetic coordinate of aircraft can be demodulated from the data stream in real time. By this way, the external guide for photoelectric theodolite can be achieved after the data processed and transmitted to the control system of photoelectric theodolite. Application results show that the guided precision has good performance in the remote target capture and good results in practical application of this technique for photoelectric theodolite. ©, 2015, Chinese Academy of Sciences. All right reserved.
Yang T.-W.,Chinese Flight Test Establishment |
Zeng X.-D.,Xidian University |
Wang H.,Chinese Flight Test Establishment
Guangzi Xuebao/Acta Photonica Sinica | Year: 2013
The measurement of aircraft LRCS is of crucial importance for the detection system evaluation and the characteristic research of the laser scattering from aircraft. A brief introduction of the measuring theory of the laser scattering from the target is presented in this paper. By analyzing the measuring condition in outfield test, the laser systems and test steps are designed for full size aircraft LRCS and verified by the experiment in laboratory. The processing data error 7% below is obtained of the laser radar cross section by using Gaussian compensation and elimination of sky background for original test data. The of measurement and analysis proves that the proposed method is effective and correct to get laser radar cross section data in outfield test.
Hu B.-H.,Chinese Flight Test Establishment |
Yan H.,Chinese Flight Test Establishment |
Wu H.,Chinese Flight Test Establishment
Journal of Applied Optics | Year: 2013
An image data measurement system was created based on the moving target performance testing requirements and the characteristics of test platform, in order to realize video recording and external parameters measurement of the target. Multiple high-speed cameras were reasonably arranged from calculated distance of the camera and mimic diagram. Camera calibration method was used which is combined the checkerboard-lattice parameter calibration in OpenCV with the line-basis field calibration. Additional, high-speed image data, midline video data and GPS data were combined to achieve the measurement of position, attitude and other external parameters. Analysis of measurement accuracy and experimental results prove that the measurement method is accurate and reliable. Its coordinate accuracy is better than 10 cm in horizontal direction and 5 cm in elevation direction, and the attitude accuracy is better than 0.5°, which fully meet the measurement accuracy requirements.
Yang Q.,Chinese Flight Test Establishment
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2015
For the purpose of complete flight test mission of a carrier-based aircraft, its arresting hook loads are measured using strain gage. A three-direction (longitudinal, lateral and vertical directions) load model of arresting hook is built through analyzing the loads in the arrest deck-landing process. Strain gages are designed and installed on the arresting hook. Ground calibration tests are implemented and load equations are constructed. Some typical loads of arresting hook in the process of carrier-based aircraft arrest deck-landing are also presented in detail, and the arresting energy and efficiency of arresting gear equipment are studied. Moreover, compared with the loads obtained by an ordinary single-direction load model, the three-direction load model is discussed. The results show that the load model and measurement methods are correct and credible, which can provide some references for the engineering practice. ©, 2015, AAAS Press of Chinese Society of Aeronautics and Astronautics. All right reserved.
Cao J.,Chinese Flight Test Establishment
Yingyong Lixue Xuebao/Chinese Journal of Applied Mechanics | Year: 2014
Based on the researches on aircraft load calibration tests with statically indeterminate support and constraints, a six degree-of-freedom aircraft statically determinate support and constraint method is proposed for the first time. According to the analysis result of load calibration tests, the aircraft landing gear support and restraint load is decomposed and simplified, a six degree of freedom aircraft statically determinate support and constrained engineering model is built up. With load calibration test, a certain type of aircraft is tested, the results show that: the theoretical calculation of aircraft constraint load and real-time monitoring can be realized and it ensures the safety, controllability of complex structural components such as aircraft wing under high load calibration conditions, the test load magnitude of aircraft wing is increased to 43% of the limit load, the wing load modeling accuracy can be controlled within 3%.
Yan-rong M.,Chinese Flight Test Establishment
27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010 | Year: 2010
To prove the validity and reliability of engine surge eliminating system ,surge test is conducted through disturbed board installed in nacelle inlet of flight bed. The test by installed the board blockage ratio of 30%, 40%, 50% on the ground and the board blockage ratio of 40% in the air were accomplished successfully .The results and date of experiment were discussed and analyzed in this paper.