Design on Model-based Visualization System for Civil Aircraft Airborne Equipment Identification Test

To meet the needs of complex system equipment testing and realize the visual management of different test projects,this article establishes a test project management system based on the actual situation of aviation equipment testing system and the concept of big data,using visual data management and analysis techniques.This system solves the comprehensive management of multi-type test projects.Combined with the actual engineering verification process,it can be found that the system can realize the visual management of test projects and effectively ensure the smooth completion of the identification test project of a certain type of aircraft′s complex system.

Qualification Test for the Reliability of Diver Gas Recovery System

A qualification test for the reliability of a newly-developed Diver Gas Recovery System (DGRS) was carried out in the Naval Medical Research Institute of the People's Liberation Army, China from March 29 to April 2, 1995. A sequential test plan of high discrimination ratio for the mean time between failures (MTBF) was adopted. The test procedures simulated those of a 300 msw dive. A hyperbaric breathing machine was used for the simulation of diver's respiratory functions. Parameters, such as diving depth, respiratory minute volume (RMV), CO2 production, gas flow rate, partial pressure of carbon dioxide, and ambient temperature and himidity were all displayed and recorded with a microcomputer system. The results indicated that no failure occurred during the 91.5 h operation. According to the acceptance and rejection criteria specified in the statistical test plan, a no-failure score in the 88 h operation is acceptable. Therefore, the DGRS has been demonstrated to meet the requirements of MTBF specified in the contract.

Efficient Method for Accelerated Reliability Qualification Testing

Based on the theoretical inference and experiment verification,a method was proposed to carry out the accelerated reliability qualification testing. First,theoretical inference was used to get the acceleration coefficients of super Gauss vibration stress and temperature stress. Then, by applying these coefficients, an accelerated reliability qualification testing curve was obtained from the standard tests. Finally,the actual experiment on a digital marine control device was carried out under the proposed testing method.The experiment result shows that the proposed method can reduce the total experiment time and improve the efficiency of the reliability qualification test.

BAYESIAN DEMONSTRATION TEST METHOD WITH MIXED BETA DISTRIBUTION

A complex mechatronics system Bayesian plan of demonstration test is studied based on the mixed beta distribution. During product design and improvement various information is appropriately considered by introducing inheritance factor, moreover, the inheritance factor is thought as a random variable, and the Bayesian decision of the qualification test plan is obtained, and the correctness of a Bayesian model presented is verified. The results show that the quantity of the test is too conservative according to classical methods under small binomial samples. Although traditional Bayesian analysis can consider test information of related or similar products, it ignores differences between such products. The method has solved the above problem, furthermore, considering the requirement in many practical projects, the differences among this method, the classical method and Bayesian with beta distribution are compared according to the plan of reliability acceptance test.

Effect of repetitive square voltage frequency on partial discharge features

The inverter-fed motor is a key component of environmental-friendly hybrid cars, high-speed trains, and other industrial applications. After the widespread use of inverter-fed motors, the repetitive impulse surges from inverters were found to cause new insulation problems in inverter-fed motors that were linked to premature insulation failure. The partial discharge (PD) induced by the overvoltage inner stator windings was found to be the root cause of insulation reliability problems. To mitigate this problem, PD detection and life testing at repetitive square voltages should be performed on new types of insulation models and entire motor insulation systems. The obtained partial discharge inception voltage (PDIV) and lifetime of insulation in the tests can be used to evaluate the insulation status of inverter-fed motor insulation systems and thus to improve the insulation designs. At AC voltage conditions, the voltage frequency can significantly affect PD activity. At repetitive square voltage with rapid rise time, the influence of the square voltage frequency on PD activity should be investigated (1) to suggest values for the repetitive square voltage frequency selection for the PDIV and lifetime tests, and (2) to increase the signal-to-noise ratio when extracting PD pulses from strong disturbances generated by the operating switch of impulse generators. Therefore, the main purpose of this paper was to investigate the effects of repetitive square voltage frequency on PD events. Insulation models of both Type I (low-voltage inverter-fed motor) and Type II (high-voltage inverter-fed motor) were used to obtain single-PD and multi-PD statistical features, respectively. Experimental results indicated that higher frequencies caused less PD events with lower PD magnitudes and shorter delay times in one square voltage cycle. This phenomenon was attributed to the different surface charge decay ratios and the initial electron emission probabilities resulting from different square voltage frequencies. Finally, a number of considerations for PD measurements on inverter-fed motors were provided to improve the sensitivity of the PD test system and to obtain high objective insulation lifetime test results, which are used to assess the insulation status of inverter-fed motors.