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.

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 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.

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.

Automated regression test method for scientific computing libraries:Illustration with SPHinXsys

Scientific computing libraries,whether in-house or open-source,have witnessed enormous progress in both engineering and scientific research.Therefore,it is important to ensure that modifications to the source code,prompted by bug fixing or new feature development,do not compromise the accuracy and functionality that have been already validated and verified.This paper introduces a method for establishing and implementing an automatic regression test environment,using the open-source multi-physics library SPHinXsys as an illustrative example.Initially,a reference database for each benchmark test is generated from observed data across multiple executions.This comprehensive database encapsulates the maximum variation range of metrics for different strategies,including the time-averaged,ensemble-averaged,and dynamic time warping methods.It accounts for uncertainties arising from parallel computing,particle relaxation,physical instabilities,and more.Subsequently,new results obtained after source code modifications undergo testing based on a curve-similarity comparison against the reference database.Whenever the source code is updated,the regression test is automatically executed for all test cases,providing a comprehensive assessment of the validity of the current results.This regression test environment has been successfully implemented in all dynamic test cases within SPHinXsys,including fluid dynamics,solid mechanics,fluid-structure interaction,thermal and mass diffusion,reaction-diffusion,and their multi-physics couplings,and demonstrates robust capabilities in testing different problems.It is noted that while the current test environment is built and implemented for a particular scientific computing library,its underlying principles are generic and can be easily adapted for use with other libraries,achieving equal effectiveness.

A deep reinforcement learning(DRL)based approach for well-testing interpretation to evaluate reservoir parameters

Parameter inversions in oil/gas reservoirs based on well test interpretations are of great significance in oil/gas industry.Automatic well test interpretations based on artificial intelligence are the most promising to solve the problem of non-unique solution.In this work,a new deep reinforcement learning(DRL)based approach is proposed for automatic curve matching for well test interpretation,by using the double deep Q-network(DDQN).The DDQN algorithms are applied to train agents for automatic parameter tuning in three conventional well-testing models.In addition,to alleviate the dimensional disaster problem of parameter space,an asynchronous parameter adjustment strategy is used to train the agent.Finally,field applications are carried out by using the new DRL approaches.Results show that step number required for the DDQN to complete the curve matching is the least among,when comparing the naive deep Q-network(naive DQN)and deep Q-network(DQN).We also show that DDQN can improve the robustness of curve matching in comparison with supervised machine learning algorithms.Using DDQN algorithm to perform 100 curve matching tests on three traditional well test models,the results show that the mean relative error of the parameters is 7.58%for the homogeneous model,10.66%for the radial composite model,and 12.79%for the dual porosity model.In the actual field application,it is found that a good curve fitting can be obtained with only 30 steps of parameter adjustment.

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.

Research of testing method based on UML statecharts

Unified modeling language （UML） is a powerful graphical modeling language with intuitional meaning. It provides various diagrams to depict system characteristics and complex environment from different viewpoints and different application layers. UML-based software development and modeling environments have been widely accepted in industry, including areas in which safety is an important issue such as spaceflight, defense, automobile, etc. To ensure and improve software quality becomes a main concern in the field. As one of the key techniques for software quality, software testing can effectively detect system faults. UML based software testing based is an important research direction in software engineering. The key to software testing is the generation of test cases. This dissertation studies an approach to generating test cases from UML statecharts.

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.

A new two-part test based on density ratio model for zero-inflated continuous distributions

In this paper,we consider testing the hypothesis concerning the means of two independent semicontinuous distributions whose observations are zero-inflated,characterized by a sizable number of zeros and positive observations from a continuous distribution.The continuous parts of the two semicontinuous distributions are assumed to follow a density ratio model.A new two-part test is developed for this kind of data.The proposed test takes the sum of one test for equality of proportions of zero values and one conditional test for the continuous distribution.The test is proved to follow a 2 distribution with two degrees of freedom.Simulation studies show that the proposed test controls the type I error rates at the desired level,and is competitive to,and most of the time more powerful than two popular tests.A real data example from a dietary intervention study is used to illustrate the usefulness of the proposed test.

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.