Research on Automatic Test System of Engine Blade Natural Frequency

Blades are one of the important components on aircraft engines.If they break due to vibration failure,the normal operation of the entire engine will be offected.Therefore,it is necessary to measure their natural frequency before installing them on the engine to avoid resonance.At present,most blade vibration testing systems require manual operation by operators,which has high requirements for operators and the testing process is also very cumbersome.Therefore,the testing efficiency is low and cannot meet the needs of efficient testing.To solve the current problems of low testing efficiency and high operational requirements,a high-precision and high-efficiency automatic test system is designed.The testing accuracy of this system can reach ±1%,and the testing efficiency is improved by 37% compared to manual testing.Firstly,the influence of compression force and vibration exciter position on natural frequency test is analyzed by amplitude-frequency curve,so as to calibrate servo cylinder and fourdimensional motion platform.Secondly,the sine wave signal is used as the excitation to sweep the blade linearly,and the natural frequency is determined by the amplitude peak in the frequency domain.Finally,the accuracy experiment and efficiency experiment are carried out on the developed test system,whose results verify its high efficiency and high precision.

Automatic Control of Automobile Transmission Performance Test Stand

To realize automatic control of automobile transmission performance test stand Methods The automatic control technique of the lubricant temperature,the program- controll- edautomaticshifting of the transmission,the continuous adjusting of revolution speed and load, data-acquisition and data real-time processing were adopted.Results The lubricant temperature was controlled at the set temperature ±2℃.The automatic shifting of the trans- mission is simple,reliable and accurate.The automatic adjusting of load and rotation speed is rapidandaccurate,the torque divergence is ±1N·m,the rotation speed divergence is ±5r/min Conclusion The four kinds of techniques are applied into the automobile transmission perfor- mance test stand successfully. mancetest stand successfully.

Comparative study of model tests on automatically formed roadway and gob-side entry driving in deep coal mines

Automatically formed roadway(AFR)by roof cutting with bolt grouting(RCBG)is a new deep coal mining technology.By using this technology,the broken roadway roof is strengthened,and roof cutting is applied to cut off stress transfer between the roadway and gob to ensure the collapse of the overlying strata.The roadway is automatically formed owing to the broken expansion characteristics of the collapsed strata and mining pressure.Taking the Suncun Coal Mine as the engineering background,the control effect of this new technology on roadways was studied.To compare the law of stress evolution and the surrounding rock control mechanisms between AFR and traditional gob-side entry driving,a comparative study of geomechanical model tests on the above methods was carried out.The results showed that the new technology of AFR by RCBG effectively reduced the stress concentration of the roadway compared with gob-side entry driving.The side abutment pressure peak of the solid coal side was reduced by 24.3%,which showed an obvious pressure-releasing effect.Moreover,the position of the side abutment pressure peak was far from the solid coal side,making it more beneficial for roadway stability.The deformation of AFR surrounding rock was also smaller than the deformation of the gob-side entry driving by the overload test.The former was more beneficial for roadway stability than the latter under higher stress conditions.Field application tests showed that the new technology can effectively control roadway deformation.Moreover,the technology reduced roadway excavation and avoided resource waste caused by reserved coal pillars.

Testing Forms in Web Applications Automatically

Forms enhance both the dynamic and interactive abilities of Web applications and the system complexity. And it is especially important to test forms completely and thoroughly. Therefore, this paper discusses how to carry out the form testing by different methods in the related testing phases. Namely, at first, automatically abstracting forms in the Web pages by parsing the HTML documents; then, ohtai ning the testing data with a certain strategies, such as by requirement specifications, by mining users＇ hefore input informarion or by recording meehanism; and next executing the testing actions automatically due to the well formed test cases; finally, a case study is given to illustrate the convenient and effective of these methods.

Automatic well test interpretation based on convolutional neural network for a radial composite reservoir

An automatic well test interpretation method for radial composite reservoirs based on convolutional neural network(CNN) is proposed, and its effectiveness and accuracy are verified by actual field data. In this paper, based on the data transformed by logarithm function and the loss function of mean square error(MSE), the optimal CNN is obtained by reducing the loss function to optimize the network with "dropout" method to avoid over fitting. The trained optimal network can be directly used to interpret the buildup or drawdown pressure data of the well in the radial composite reservoir, that is, the log-log plot of the given measured pressure variation and its derivative data are input into the network, the outputs are corresponding reservoir parameters(mobility ratio, storativity ratio, dimensionless composite radius, and dimensionless group characterizing well storage and skin effects), which realizes the automatic initial fitting of well test interpretation parameters. The method is verified with field measured data of Daqing Oilfield. The research shows that the method has high interpretation accuracy, and it is superior to the analytical method and the least square method.

Study on Test Compaction in High-Level Automatic Test Pattern Generation (ATPG) Platform

Advancements in semiconductor technology are making gate-level test generation more challenging. This is because a large amount of detailed structural information must be processed in the search process of automatic test pattern generation (ATPG). In addition, ATPG needs to deal with new defects caused by process variation when IC is shrinking. To reduce the computation effort of ATPG, test generation could be started earlier at higher abstraction level, which is in line with top-down design methodology that has become more popular nowadays. In this research, we employ Chen’s high-level fault model in the high-level ATPG. Besides shorter ATPG time as shown in many previous works, our study showed that high-level ATPG also contributes to test compaction. This is because most of the high-level faults correlate with the gate-level collapsed faults especially at input/output of the modules in a circuit. The high-level ATPG prototype used in our work is mainly composed by constraint-driven test generation engine and fault simulation engine. Experimental result showed that more reduced/compact test set can be generated from the high-level ATPG.

Reducing Item Exposure in Computerized Adaptive Testing Systems Using Automatic Item Generation

This paper studies the technics of reducing item exposure by utilizing automatic item generation methods. Known test item calibration method uses item parameter estimation with the statistical data, collected during examinees prior testing. Disadvantage of the mentioned item calibration method is the item exposure; when test items become familiar to the examinees. To reduce the item exposure, automatic item generation method is used, where item models are being constructed based on already calibrated test items without losing already estimated item parameters. A technic of item model extraction method from the already calibrated and therefore exposed test items described, which can be used by the test item development specialists to integrate automatic item generation principles with the existing testing applications.

A Method for Modeling the Virtual Instrument Automatic Test System Based on the Petri Net

Virtual instrument is playing the important role in automatic test system. This paper introduces a composition of a virtual instrument automatic test system and takes the VXIbus based a test software platform which is developed by CAT lab of the UESTC as an example. Then a method to model this system based on Petri net is proposed. Through this method, we can analyze the test task scheduling to prevent the deadlock or resources conflict. At last, this paper analyzes the feasibility of this method.

An Automatic Testing System of Scheduling Strategies in Real-Time UNIX

This paper proposes a formal model of the automatic testing system for scheduling strategies in real-time UNIX and describes the algorithm of the key part of the system. The model of the system is an important technology of the automatization of software development. According to the model presented in the paper, many different kinds of automatic testing systems can be designed and developed easily. At the end of the paper, the prototype proves the feasibility of the model and design.

Automatic lifting system design and application of large load powered support test rig

This paper presented a design of an automatic lifting system. It is used for large load powered support and improves the old method wherein powered support lifting depends on manual control. This system applies a high accuracy gear shunt motor to match the flow for 4 lifting cylinders, and also allocates bypass throttles to realize automatic lifting. Through the dis- placement sensor feedback the height deviation among 4 lifting cylinders during the whole lifting process, when the deviation is up to the sitting value, the corresponding bypass throttle is operated immediately to reduce the deviation, so that the moving platform of the powered support would not be stuck. Through real application, it is shown that this system can realize automatic lifting of powered support; the lifting speed is controlled between 5 and 10 mm/s, and the final aligning accuracy is up to 1 mm.

Aware Time in Bug Fix—A Novel Automatic Test Case Selection for Prioritization of Version Control

The supreme goal of the Automatic Test case selection techniques is to guarantee systematic coverage, to recognize the usual error forms and to lessen the test of redundancy. It is unfeasible to carry out all the test cases consistently. For this reason, the test cases are picked and prioritize it. The major goal of test case prioritization is to prioritize the test case sequence and finds faults as early as possible to improve the efficiency. Regression testing is used to ensure the validity and the enhancement part of the changed software. In this paper, we propose a new path compression technique (PCUA) for both old version and new version of BPEL dataset. In order to analyze the enhancement part of an application and to find an error in an enhancement part of an application, center of the tree has been calculated. Moreover in the comparative analysis, our proposed PCUA- COT technique is compared with the existing XPFG technique in terms of time consuming and error detection in the path of an enhancement part of BPEL dataset. The experimental results have been shown that our proposed work is better than the existing technique in terms of time consuming and error detection.

Test Method for Evaluating the Cleaning Performance of Proteases in Automatic Dishwashing Detergent

A test method was developed to better evaluate the cleaning performance of protease in Chinese automatic dishwashing detergent(ADD)and differentiate the washing performance of different ADD formulations on protein stains.Steamed egg stain,which was a Chinese-consumers-relevant soil,was used as monitor.The response curves of the stain to different amounts of protease were measured under laboratory conditions,and the stain removal ability of commercially available ADDs was tested with this method.The results showed that the soil removal rate of ADD without protease was less than 10%,and the soil removal rate increased with the increase of protease dosage in the range of 0~2.0%.Steamed egg stain had a good response to protease,and it could effectively distinguish the cleaning performance of commercial ADDs.The test method could be used in the development,screening and evaluation of ADD formulations.

Application of clutch to clutch gear shift technology for a new automatic transmission

For the purpose of engineering development for a new 8-step speed automatic transmission,a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed.Aiming at four different shift types,the ideal characteristics of shift clutch and engine control were set up.By using torque estimation method,PI slip control algorithm and engine coordinated control principle,the control model and transmission controller were well developed for three shift phases which included rapid-fill phase,torque phase and inertia phase.The testing environment on the rig and prototype vehicle level was built and the testing results obtained in ultimate condition could verify the accuracy and feasibility of this shift control strategy.The peak jerk during shift process was controlled within ±2 g/s where the smooth gearshift was obtained.The development proposal and algorithm have a high value for engineering application.

Investigation into the automatic recognition of time series precursor of earthquakes

In this paper, a new method of quantitative description of earthquake precursors is proposed; by this method, the precursory pattern of time series can be quantitatively described with a two-dimensional matrix. On this basis, a method of automatic recognition or automatic acquirement of precursory pattern, called simply the AA method, is put forward. Then, taking North China region as an example, various seismological precursors such as the frequency, energy, b -value, etc . and various nonlinear parameter precursors such as the capacity dimension, information dimension, correlation dimension, Hurst index and its difference, etc. are analyzed and the 8 time series so obtained are recognized automatically using the proposed precursory pattern and AA method. Besides, C-method tests and very rigorous HF (history and future) tests are made. The result shows that the R-value of prediction efficacy assessment is fairly high.

METARO^(3):Metamorphic Relation Group for Automatic Program Repair

The application of metamorphic testing(MT)on automatic program repair(APR-MT)is used to generate a patch without test oracles by examining whether the input metamorphic relation(MR)is satisfied or not.However,the delivered patch is plausible since it may satisfy the input MR but violate other MRs.This inspires us to propose an improved approach to enhance the effectiveness of APR-MT with metamorphic relation group.Ourapproach involves three major steps.First,we formally define the repair process of APR-MT by building the model of automatic program repair and metamorphic testing separately.Then,we propose the advanced model of automatic program repair based on metamorphic relation group,named METARO^(3),which takes several MRs as input while only one MR is used in APR-MT.We additionally present two kinds of selection strategies to rank MRs in descending order of the fault detection capability,which helps shorten the repair time of finding a patch.To demonstrate the feasibility and procedure of our approach,an illustration example was conducted.The results show that METARO^(3) can improve the effectiveness of APR-MT significantly.

Analysis on the gear-shifting schedule of hydraulic automatic transmission

With an advanced foreign hydraulic automatic transmission as the objective,an analytical method for the gear-shifting schedule is proposed.First the demanded maximum gradient of test is estimated.Then a test scheme and analytical procedure is formulated by initial test and hypothetical shift parameters.Finally through gear-shifting tests under different road conditions,load,accelerator pedal position limitation,throttle opening and output shaft speed are found to be the gear-shifting parameters.Under a common road condition,the gear-shifting schedule is a double-parameter schedule.Based on the driver＇s demands on braking and dynamic performance,different shift schedules are made under downhill,uphill and quick releasing acceleration pedal conditions.The operation criteria of down-shift schedule on abrupt grade are proposed.

基于TestStand的DDS特性参数自动测试管理

介绍了基于TestStand软件对DDS特性参数进行自动化测试的流程管理。DDS测试参数包括常规参数和特性参数,常规参数由普通的专用测试设备即可测试,而特性参数由于测试项目繁多,测试要求高,采用普通的测试设备难以测全所有参数,且精度难以保证,通过外接高性能专用仪器对其测试是比较好的测试方案。由此带来的问题是测试资源杂多,需要一个统一的测试管理平台,对测试资源和测试流程做统一的测试管理。TestStand软件是一款非常优秀的测试管理软件,应用TestStand软件对DDS复杂的自动测试流程进行管理,方便了测试开发过程,极大地提高了测试开发效率。

可视化测试软件平台GTEST

针对现有自动测试软件开发平台大多以文本形式通用程序语言为基础的现状,描述了一种以面向对象方法和组件技术设计实现的、基于数据库的通用可视化测试软件平台 GTEST。该平台采用开发平台和运行平台分离的形式,实现了测试策略树及测试流程的可视化编辑,以及测试程序集的运行和测试报告的自动生成。该软件平台使测试人员和操作人员摆脱了繁琐的编程工作,提高了自动测试系统的开发效率。

基于AdmiTest的CTCS-3级列控系统自动测试平台

根据CTCS-3级列控系统的特点,结合欧洲列车运行控制系统(ETCS)测试经验,研发基于通用测试平台AdmiTest的CTCS-3级列控系统自动测试平台CARSTool。CARSTool采用激励-反馈机制实现单系统或多系统的闭环测试,包含测试对象、仿真系统、链路、消息、激励、响应和测试序列等基本元素,具有线路工程数据配置、通信链路配置、站场线路配置、PI Object、仿真系统、列车运行仿真和自动测试序列7个功能模块。以郑西客运专线列控数据为例,采用CARSTool对CTCS-3级列控系统进行仿真测试。测试结果表明:通过规范化语法严格卡控测试步骤,根据CTCS-3级列控系统测试案例库以及激励-反馈信息判断测试项目的执行状态,CARSTool实现了测试计划、执行过程和测试结果的闭环处理;说明CARSTool能够实现CTCS-3级列控系统的自动测试。

基于TestCenter软件平台自动测试系统设计

随着通信技术的快速发展,目前市场上无线电测试类仪器保有量快速扩充,测试任务逐年增长。面对快速增长业务,传统的人工手动测试方式已不能满足市场需求。针对以上问题,采用TestCenter软件平台,结合已有计量标准设备,适当增加接口及智能开关设备,设计了一套通用自动测试系统。经验证,该自动测试系统操作简单,运行可靠,测试速度快。