Aeropropulsion System Test Facility (ASTF) is required to accurately control the pressure and temperature of the airflow to test the performance of the aero-engine. However, the control accuracy of ASTF is significant...Aeropropulsion System Test Facility (ASTF) is required to accurately control the pressure and temperature of the airflow to test the performance of the aero-engine. However, the control accuracy of ASTF is significantly affected by the flow disturbance caused by aero-engine acceleration and deceleration. This would reduce the credibility of ASTF’s test results for the aero-engine. Therefore, first, this paper proposes a feedforward compensation-based L1 adaptive control method for ASTF to address this problem. The baseline controller is first designed based on ideal uncoupled closed-loop dynamics to achieve dynamic decoupling. Then, L1 adaptive control is adopted to deal with various uncertainties and ensure good control performance. To further enhance the anti-disturbance performance, a feedforward strategy based on disturbance prediction is designed in the L1 adaptive control framework to compensate for the unmatched flow disturbance, which cannot be measured directly. In addition, this strategy takes into account the effects of actuator dynamics. With this method, the feedforward term can be determined from the nominal model parameters despite uncertainties. Finally, to demonstrate the effectiveness of the proposed method, various comparative experiments are performed on a hardware-in-the-loop system of ASTF. The experimental results show that the proposed method possesses excellent tracking performance, anti-disturbance performance and robustness.展开更多
Due to the dynamic coupling and multi-source uncertainties,it is difficult to accurately control the pressure and temperature of the Aeropropulsion System Test Facility(ASTF)in the presence of rapid command and large ...Due to the dynamic coupling and multi-source uncertainties,it is difficult to accurately control the pressure and temperature of the Aeropropulsion System Test Facility(ASTF)in the presence of rapid command and large disturbance.This paper presents the design ofμ-synthesis control to solve the problem.By incorporating the pressure ratio into the linear equation of the control valve,the modeling error of ASTF in the low frequency range is effectively reduced.Then,an uncertain model is established by considering various factors,including parameter variations,modeling error in the low frequency range,unmodeled dynamics,and changes in the working point.To address the dynamic coupling,a diagonal reference model with desired performance is incorporated intoμ-synthesis.Furthermore,all weighting functions are designed according to the performance requirements.Finally,theμ-controller is obtained by using the standardμ-synthesis method.Simulation results indicate that theμ-controller decouples the pressure and temperature dynamics of ASTF.Compared with the multivariable PI controller,integral-μcontroller,and double integral-μcontroller,the proposedμ-controller can achieve higher transient accuracy and better disturbance rejection.Moreover,the robustness of theμ-controller is demonstrated by Monte Carlo simulations.展开更多
Safety system testing is one of the most rigorous and time-consuming requirements in the verification and validation process for reactor protection systems(RPSs).This paper presents the development of a test system fo...Safety system testing is one of the most rigorous and time-consuming requirements in the verification and validation process for reactor protection systems(RPSs).This paper presents the development of a test system for the fully digital and field-programmable gate array-based RPS of the solid fuel(SF) thorium-breeding molten salt pebble bed fluoride salt-cooled reactor(TMSR),denoted as the TMSR-SF1 project,developed by the Chinese Academy of Sciences.The test system is applied to the RPS to ensure that it fully meets its designed functions and system specifications.We first introduce the testing principles and methods.Then,the hardware component designs and the software program development of the test system are discussed.Finally,the test process and test results are discussed and summarized.展开更多
In order to realize the real-time and precise test for a weapon system of a certain type of fighter,a signal classification method according to attributes is proposed,common input channels for multiple signals are con...In order to realize the real-time and precise test for a weapon system of a certain type of fighter,a signal classification method according to attributes is proposed,common input channels for multiple signals are configured optimally,and a test adapter and an adaptive signal conditioning module is designed. The hardware of conditioning module can be configured flexibly and the programmable test range can be adjusted owing to programmable multiplexer. An FPGA adaptive filter is designed by the calculated filter coefficient vectors with LMS method to solve the problem of parallel test of fighter weapon system in electromagnetic interference environment. The adaptive signal conditioning technology is characterized by high efficiency,precision and integration. Its application makes the test system successful to conduct real-time and parallel test for a weapon system,which is developed based on VXI bus and virtual-instrument technology.展开更多
Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instr...Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instruction-brief and instruction-category, and constructing test suite. Consequently, this approach is adopted to test oven embedded system, and detail process is deeply discussed. As a result, the factual result indicates that the “instruction-category” approach can be effectively applied in embedded system testing as a black-box method for conformity testing.展开更多
Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerody...Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerodynamic parameters of the airplane model are studied. In detail, a static model of the wire-driven parallel suspension is analyzed, a mathematical model for describ- ing the aerodynamic loads exerted on the scale model is constructed and a calculation method for obtaining the aerodynamic parameters of the model by measuring the tension of wires is presented. Moreover, the measurement system for wire tension and its corresponding data acquisition system are designed and built. Thereafter, the wire-driven parallel suspension system is placed in an open return circuit low-speed wind tunnel for wind tunnel tests to acquire data of each wire tension when the airplane model is at different attitudes and different wind speeds. A group of curves about the parameters for aerodynamic load exerted on the airplane model are obtained at different wind speeds after the acquired data are analyzed. The research results validate the feasibility of using a wire-driven parallel manipulator as the suspension system for low-speed wind ttmnel tests.展开更多
Fundamental power couplers are crucial components for feeding radio frequency power to accelerating cavities. Couplers must be tested and conditioned on a room-temperature test stand to evaluate and potentially improv...Fundamental power couplers are crucial components for feeding radio frequency power to accelerating cavities. Couplers must be tested and conditioned on a room-temperature test stand to evaluate and potentially improve their performance before being installed in an accelerating cavity. A new test system has been designed and is under construction at the institute of modern physics.For this test system, multiple conditioning modes, including the pulse mode, CW mode, and amplitude-sweeping mode, have been embedded in the low-level radio frequency system of the test stand. All of these conditioning modes can be run manually or automatically. In addition, a novel test cavity is proposed and has been designed, which facilitates non-contact conditioning and a multi-purpose test stand.展开更多
Recently, flutter active control using linear parameter varying（LPV） framework has attracted a lot of attention. LPV control synthesis usually generates controllers that are at least of the same order as the aeroela...Recently, flutter active control using linear parameter varying（LPV） framework has attracted a lot of attention. LPV control synthesis usually generates controllers that are at least of the same order as the aeroelastic models. Therefore, the reduced-order model is required by synthesis for avoidance of large computation cost and high-order controller. This paper proposes a new procedure for generation of accurate reduced-order linear time-invariant（LTI） models by using system identification from flutter testing data. The proposed approach is in two steps. The well-known poly-reference least squares complex frequency（p-LSCF） algorithm is firstly employed for modal parameter identification from frequency response measurement. After parameter identification,the dominant physical modes are determined by clear stabilization diagrams and clustering technique. In the second step, with prior knowledge of physical poles, the improved frequencydomain maximum likelihood（ML） estimator is presented for building accurate reduced-order model. Before ML estimation, an improved subspace identification considering the poles constraint is also proposed for initializing the iterative procedure. Finally, the performance of the proposed procedure is validated by real flight flutter test data.展开更多
In software testing, many troublesome faults are caused by interaction of input parameters. If automatic efficient test-case generator（AETG）, in parameter order（IPO） or orthogonal Latin square is used in the softw...In software testing, many troublesome faults are caused by interaction of input parameters. If automatic efficient test-case generator（AETG）, in parameter order（IPO） or orthogonal Latin square is used in the software system under test, the whole test set cannot be run completely due to time or budget constraints. In this paper, according to the number of parameter k and their values n, a software system under test can be divided into four types. As for k-2 system, an algorithm was proposed to construct test rases, based on the longitudinal binary string set and method of controlling variables. As for k-n valued parameters whose n was a prime or power of prime, a method of covering array of test sets was designed to construct test sets by taking orthogonal array and derive arrays from orthogonal array and two useful conditions. As for k parameters whose n-value was not all equal, an experience algorithm was presented in this paper. The experimental results show that the size of test sets from the proposed methods is better than that from AETG, IPO, and orthogonal Latin square.展开更多
An S-lay crane barge,named CNOOC 201,has been built for pipe laying in deepwater oil/gas fields in the South China Sea.It is due to be commissioned by the end of the year 2010.A special lifting system is developed to ...An S-lay crane barge,named CNOOC 201,has been built for pipe laying in deepwater oil/gas fields in the South China Sea.It is due to be commissioned by the end of the year 2010.A special lifting system is developed to meet the challenge that installing deepwater risers from an S-lay barge is difficult and has not been achieved.The purpose of this paper was to investigate the model test on such an innovative system,which has to be done before field application.By applying the similarity theory,the movement of the S-lay barge is simulated through a six degrees-of-freedom motion platform,and a truncated model riser is utilized for the model testing.The displacement and force boundary conditions at the truncated position of the riser are obtained from the catenary governing equation and become realized by a slideway cart and a loading system designed to control the configuration of the model riser,which presents a similar configuration to a real riser in deepwater.The test results are in very good agreement with theoretical calculations,showing that the active truncated test is applicable for controlling the configuration of the deepwater riser in model testing investigation.展开更多
In order to deal with the limitations during the register transfer level verification, a new functional verification method based on the random testing for the system-level of system-on-chip is proposed.The validity o...In order to deal with the limitations during the register transfer level verification, a new functional verification method based on the random testing for the system-level of system-on-chip is proposed.The validity of this method is proven theoretically.Specifically, testcases are generated according to many approaches of randomization.Moreover, the testbench for the system-level verification according to the proposed method is designed by using advanced modeling language.Therefore, under the circumstances that the testbench generates testcases quickly, the hardware/software co-simulation and co-verification can be implemented and the hardware/software partitioning planning can be evaluated easily.The comparison method is put to use in the evaluation approach of the testing validity.The evaluation result indicates that the efficiency of the partition testing is better than that of the random testing only when one or more subdomains are covered over with the area of errors, although the efficiency of the random testing is generally better than that of the partition testing.The experimental result indicates that this method has a good performance in the functional coverage and the cost of testing and can discover the functional errors as soon as possible.展开更多
The accuracy of fluctuating pressure test in wind tunnel is affected by the tube system. By employing contradistinctive experimental method, systematic study was conducted to investigate the effects of the tube system...The accuracy of fluctuating pressure test in wind tunnel is affected by the tube system. By employing contradistinctive experimental method, systematic study was conducted to investigate the effects of the tube system on fluctuating pressure. The analyzed tube system parameters include tube length, inside diameter, curvature, deflection angle, thickness, material, restrictor length,restrictor inside diameter, and restrictor place. It is found that all the tube system parameters mentioned above except tube curvature have non-negligible effects on fluctuating pressure. Based on the research results, test methods were presented for the fluctuating pressure measurement in low-speed wind tunnel, which can obviously improve the data accuracy but not lose test efficiency. The effectiveness of the method is verified by the wind tunnel test.展开更多
New tests for checking asymptotic stability of positive 1D continuous-time and discrete-time linear systems without and with delays and of positive 2D linear systems described by the general and the Roesser models are...New tests for checking asymptotic stability of positive 1D continuous-time and discrete-time linear systems without and with delays and of positive 2D linear systems described by the general and the Roesser models are proposed. Checking of the asymptotic stability of positive 2D linear systems is reduced to checking of suitable corresponding 1D positive linear systems. It is shown that the stability tests can be also applied to checking the asymptotic stability of fractional discrete-time linear systems with delays. Effectiveness of the tests is shown on numerical examples.展开更多
In order to research the effects of built-in test(BIT) on the system and select BITand test strategy,the complex repairable systems with BITequipment are modeled and simulated by using Simulink.Based on the model,the ...In order to research the effects of built-in test(BIT) on the system and select BITand test strategy,the complex repairable systems with BITequipment are modeled and simulated by using Simulink.Based on the model,the influences of different built-in test equipments,maintenance time and error probabilities on the system usability are evaluated.The simulation results showthat they effect on the system differently.The simulation method of complex system based on Simulink provides a technique approach to research the effects of BITon the system and select BITand test strategy.展开更多
The researchers who study the local area network( LAN) eXtension for instrumentation( LXI) instrument are pursuing instrument's high-precision synchronization. In the paper,three synchronization modes were discuss...The researchers who study the local area network( LAN) eXtension for instrumentation( LXI) instrument are pursuing instrument's high-precision synchronization. In the paper,three synchronization modes were discussed which were clock synchronization, trigger synchronization, and response synchronization. Synchronous process between LXI instruments was analyzed and each time factor affecting the synchronization accuracy was discussed. On the basis of the analysis,it can be found that delay trigger plays an important role in the network testing system's synchronization. Delay trigger can produce an additional time interval to correct the difference of each LXI instrument's response time. Then,a method to realize the delay trigger was introduced. Delay time can be adjustable according to the actual demand. Finally,synchronization accuracy of network testing system can reach nanoseconds.展开更多
It is necessary to perform the test of system on chip,the test scheduling determines the test start and finishing time of every core in the system on chip such that the overall test time is minimized.A new test schedu...It is necessary to perform the test of system on chip,the test scheduling determines the test start and finishing time of every core in the system on chip such that the overall test time is minimized.A new test scheduling approach based on chaotic ant colony algorithm is presented in this paper.The optimization model of test scheduling was studied,the model uses the information such as the scale of test sets of both cores and user defined logic.An approach based on chaotic ant colony algorithm was proposed to solve the optimization model of test scheduling.The test of signal integrity faults such as crosstalk were also investigated when performing the test scheduling.Experimental results on many circuits show that the proposed approach can be used to solve test scheduling problems.展开更多
随着Internet的日益发展、普及,人们对WEB的要求越来越高,需要灵活的动态网页技术。动态网页技术ASP具有保密性好、与所有脚本语言兼容、易编写、无需编译等特点,且ASP在与数据库的连接上采用ADO(ActiveX Data Objects)技术访问后台数据...随着Internet的日益发展、普及,人们对WEB的要求越来越高,需要灵活的动态网页技术。动态网页技术ASP具有保密性好、与所有脚本语言兼容、易编写、无需编译等特点,且ASP在与数据库的连接上采用ADO(ActiveX Data Objects)技术访问后台数据库,这些深受网页制作者的欢迎。在Online Testing System中动态网页制作中采用ASP,具有一定实用价值。展开更多
基金supported by the“Shuimu Tsinghua Scholar”Project,China(No.2024SM223)the National Science and Technology Major Project,China(No.Y2022-V-0002-0028).
文摘Aeropropulsion System Test Facility (ASTF) is required to accurately control the pressure and temperature of the airflow to test the performance of the aero-engine. However, the control accuracy of ASTF is significantly affected by the flow disturbance caused by aero-engine acceleration and deceleration. This would reduce the credibility of ASTF’s test results for the aero-engine. Therefore, first, this paper proposes a feedforward compensation-based L1 adaptive control method for ASTF to address this problem. The baseline controller is first designed based on ideal uncoupled closed-loop dynamics to achieve dynamic decoupling. Then, L1 adaptive control is adopted to deal with various uncertainties and ensure good control performance. To further enhance the anti-disturbance performance, a feedforward strategy based on disturbance prediction is designed in the L1 adaptive control framework to compensate for the unmatched flow disturbance, which cannot be measured directly. In addition, this strategy takes into account the effects of actuator dynamics. With this method, the feedforward term can be determined from the nominal model parameters despite uncertainties. Finally, to demonstrate the effectiveness of the proposed method, various comparative experiments are performed on a hardware-in-the-loop system of ASTF. The experimental results show that the proposed method possesses excellent tracking performance, anti-disturbance performance and robustness.
基金the National Science and Technology Major Project,China(No.J2019-V-0010-0104)the Postdoctoral Science Foundation of China(No.2021M690289)+1 种基金the National Natural Science Foundation of China(No.52105138)Zhejiang Provincial Natural Science Foundation of China(No.LQ23E060007).
文摘Due to the dynamic coupling and multi-source uncertainties,it is difficult to accurately control the pressure and temperature of the Aeropropulsion System Test Facility(ASTF)in the presence of rapid command and large disturbance.This paper presents the design ofμ-synthesis control to solve the problem.By incorporating the pressure ratio into the linear equation of the control valve,the modeling error of ASTF in the low frequency range is effectively reduced.Then,an uncertain model is established by considering various factors,including parameter variations,modeling error in the low frequency range,unmodeled dynamics,and changes in the working point.To address the dynamic coupling,a diagonal reference model with desired performance is incorporated intoμ-synthesis.Furthermore,all weighting functions are designed according to the performance requirements.Finally,theμ-controller is obtained by using the standardμ-synthesis method.Simulation results indicate that theμ-controller decouples the pressure and temperature dynamics of ASTF.Compared with the multivariable PI controller,integral-μcontroller,and double integral-μcontroller,the proposedμ-controller can achieve higher transient accuracy and better disturbance rejection.Moreover,the robustness of theμ-controller is demonstrated by Monte Carlo simulations.
基金supported by the Leading Science and Technology Project of Chinese Academy of Sciences(No.XD02001003)
文摘Safety system testing is one of the most rigorous and time-consuming requirements in the verification and validation process for reactor protection systems(RPSs).This paper presents the development of a test system for the fully digital and field-programmable gate array-based RPS of the solid fuel(SF) thorium-breeding molten salt pebble bed fluoride salt-cooled reactor(TMSR),denoted as the TMSR-SF1 project,developed by the Chinese Academy of Sciences.The test system is applied to the RPS to ensure that it fully meets its designed functions and system specifications.We first introduce the testing principles and methods.Then,the hardware component designs and the software program development of the test system are discussed.Finally,the test process and test results are discussed and summarized.
基金Sponsored by the Key Equipment Research Project of Air Force of China (KJZ06119)
文摘In order to realize the real-time and precise test for a weapon system of a certain type of fighter,a signal classification method according to attributes is proposed,common input channels for multiple signals are configured optimally,and a test adapter and an adaptive signal conditioning module is designed. The hardware of conditioning module can be configured flexibly and the programmable test range can be adjusted owing to programmable multiplexer. An FPGA adaptive filter is designed by the calculated filter coefficient vectors with LMS method to solve the problem of parallel test of fighter weapon system in electromagnetic interference environment. The adaptive signal conditioning technology is characterized by high efficiency,precision and integration. Its application makes the test system successful to conduct real-time and parallel test for a weapon system,which is developed based on VXI bus and virtual-instrument technology.
文摘Being different from testing for popular GUI software, the “instruction-category” approach is proposed for testing embedded system. This approach is constructed by three steps including refining items, drawing instruction-brief and instruction-category, and constructing test suite. Consequently, this approach is adopted to test oven embedded system, and detail process is deeply discussed. As a result, the factual result indicates that the “instruction-category” approach can be effectively applied in embedded system testing as a black-box method for conformity testing.
基金National Natural Science Foundation of China (50475099)
文摘Owing to the advantages of wire-driven parallel manipulator, a new wire-driven parallel suspension system for airplane model in low-speed wind tunnel is constructed, and the methods to measure and calculate the aerodynamic parameters of the airplane model are studied. In detail, a static model of the wire-driven parallel suspension is analyzed, a mathematical model for describ- ing the aerodynamic loads exerted on the scale model is constructed and a calculation method for obtaining the aerodynamic parameters of the model by measuring the tension of wires is presented. Moreover, the measurement system for wire tension and its corresponding data acquisition system are designed and built. Thereafter, the wire-driven parallel suspension system is placed in an open return circuit low-speed wind tunnel for wind tunnel tests to acquire data of each wire tension when the airplane model is at different attitudes and different wind speeds. A group of curves about the parameters for aerodynamic load exerted on the airplane model are obtained at different wind speeds after the acquired data are analyzed. The research results validate the feasibility of using a wire-driven parallel manipulator as the suspension system for low-speed wind ttmnel tests.
基金supported by the National Key Basic Research Program of China(973 Program)(No.2014CB845504)
文摘Fundamental power couplers are crucial components for feeding radio frequency power to accelerating cavities. Couplers must be tested and conditioned on a room-temperature test stand to evaluate and potentially improve their performance before being installed in an accelerating cavity. A new test system has been designed and is under construction at the institute of modern physics.For this test system, multiple conditioning modes, including the pulse mode, CW mode, and amplitude-sweeping mode, have been embedded in the low-level radio frequency system of the test stand. All of these conditioning modes can be run manually or automatically. In addition, a novel test cavity is proposed and has been designed, which facilitates non-contact conditioning and a multi-purpose test stand.
基金co-supported by the National Natural Science Foundation of China (Nos. 61134004 and 61573289)Aeronautical Science Foundation of China (No. 20140753010)the Fundamental Research Funds for the Central Universities (No. 3102015BJ004)
文摘Recently, flutter active control using linear parameter varying（LPV） framework has attracted a lot of attention. LPV control synthesis usually generates controllers that are at least of the same order as the aeroelastic models. Therefore, the reduced-order model is required by synthesis for avoidance of large computation cost and high-order controller. This paper proposes a new procedure for generation of accurate reduced-order linear time-invariant（LTI） models by using system identification from flutter testing data. The proposed approach is in two steps. The well-known poly-reference least squares complex frequency（p-LSCF） algorithm is firstly employed for modal parameter identification from frequency response measurement. After parameter identification,the dominant physical modes are determined by clear stabilization diagrams and clustering technique. In the second step, with prior knowledge of physical poles, the improved frequencydomain maximum likelihood（ML） estimator is presented for building accurate reduced-order model. Before ML estimation, an improved subspace identification considering the poles constraint is also proposed for initializing the iterative procedure. Finally, the performance of the proposed procedure is validated by real flight flutter test data.
基金National Natural Science Foundation of China ( No. 61073163)Project of Science and Technology Commission of Shanghai Municipality,China ( No. 09220503000)
文摘In software testing, many troublesome faults are caused by interaction of input parameters. If automatic efficient test-case generator（AETG）, in parameter order（IPO） or orthogonal Latin square is used in the software system under test, the whole test set cannot be run completely due to time or budget constraints. In this paper, according to the number of parameter k and their values n, a software system under test can be divided into four types. As for k-2 system, an algorithm was proposed to construct test rases, based on the longitudinal binary string set and method of controlling variables. As for k-n valued parameters whose n was a prime or power of prime, a method of covering array of test sets was designed to construct test sets by taking orthogonal array and derive arrays from orthogonal array and two useful conditions. As for k parameters whose n-value was not all equal, an experience algorithm was presented in this paper. The experimental results show that the size of test sets from the proposed methods is better than that from AETG, IPO, and orthogonal Latin square.
基金support from the National Natural Science Foundation of China (granted number 50979113)the National 863 Program of China (granted number 2006AA09A105)
文摘An S-lay crane barge,named CNOOC 201,has been built for pipe laying in deepwater oil/gas fields in the South China Sea.It is due to be commissioned by the end of the year 2010.A special lifting system is developed to meet the challenge that installing deepwater risers from an S-lay barge is difficult and has not been achieved.The purpose of this paper was to investigate the model test on such an innovative system,which has to be done before field application.By applying the similarity theory,the movement of the S-lay barge is simulated through a six degrees-of-freedom motion platform,and a truncated model riser is utilized for the model testing.The displacement and force boundary conditions at the truncated position of the riser are obtained from the catenary governing equation and become realized by a slideway cart and a loading system designed to control the configuration of the model riser,which presents a similar configuration to a real riser in deepwater.The test results are in very good agreement with theoretical calculations,showing that the active truncated test is applicable for controlling the configuration of the deepwater riser in model testing investigation.
基金supported by the National High Technology Research and Development Program of China (863 Program) (2002AA1Z1490)Specialized Research Fund for the Doctoral Program of Higher Education (20040486049)the University Cooperative Research Fund of Huawei Technology Co., Ltd
文摘In order to deal with the limitations during the register transfer level verification, a new functional verification method based on the random testing for the system-level of system-on-chip is proposed.The validity of this method is proven theoretically.Specifically, testcases are generated according to many approaches of randomization.Moreover, the testbench for the system-level verification according to the proposed method is designed by using advanced modeling language.Therefore, under the circumstances that the testbench generates testcases quickly, the hardware/software co-simulation and co-verification can be implemented and the hardware/software partitioning planning can be evaluated easily.The comparison method is put to use in the evaluation approach of the testing validity.The evaluation result indicates that the efficiency of the partition testing is better than that of the random testing only when one or more subdomains are covered over with the area of errors, although the efficiency of the random testing is generally better than that of the partition testing.The experimental result indicates that this method has a good performance in the functional coverage and the cost of testing and can discover the functional errors as soon as possible.
基金supported by the Pre-research Fund of Vibration and Noise Control Technology (No. 51334060101)
文摘The accuracy of fluctuating pressure test in wind tunnel is affected by the tube system. By employing contradistinctive experimental method, systematic study was conducted to investigate the effects of the tube system on fluctuating pressure. The analyzed tube system parameters include tube length, inside diameter, curvature, deflection angle, thickness, material, restrictor length,restrictor inside diameter, and restrictor place. It is found that all the tube system parameters mentioned above except tube curvature have non-negligible effects on fluctuating pressure. Based on the research results, test methods were presented for the fluctuating pressure measurement in low-speed wind tunnel, which can obviously improve the data accuracy but not lose test efficiency. The effectiveness of the method is verified by the wind tunnel test.
文摘New tests for checking asymptotic stability of positive 1D continuous-time and discrete-time linear systems without and with delays and of positive 2D linear systems described by the general and the Roesser models are proposed. Checking of the asymptotic stability of positive 2D linear systems is reduced to checking of suitable corresponding 1D positive linear systems. It is shown that the stability tests can be also applied to checking the asymptotic stability of fractional discrete-time linear systems with delays. Effectiveness of the tests is shown on numerical examples.
文摘In order to research the effects of built-in test(BIT) on the system and select BITand test strategy,the complex repairable systems with BITequipment are modeled and simulated by using Simulink.Based on the model,the influences of different built-in test equipments,maintenance time and error probabilities on the system usability are evaluated.The simulation results showthat they effect on the system differently.The simulation method of complex system based on Simulink provides a technique approach to research the effects of BITon the system and select BITand test strategy.
基金Sino-German Joint Research Project of the Sino-German Center for Science(No.GZ817)the Fundamental Research Funds for the Central Universities,China(No.ZYGX2012 J090)National Natural Science Foundation of China(No.61271035)
文摘The researchers who study the local area network( LAN) eXtension for instrumentation( LXI) instrument are pursuing instrument's high-precision synchronization. In the paper,three synchronization modes were discussed which were clock synchronization, trigger synchronization, and response synchronization. Synchronous process between LXI instruments was analyzed and each time factor affecting the synchronization accuracy was discussed. On the basis of the analysis,it can be found that delay trigger plays an important role in the network testing system's synchronization. Delay trigger can produce an additional time interval to correct the difference of each LXI instrument's response time. Then,a method to realize the delay trigger was introduced. Delay time can be adjustable according to the actual demand. Finally,synchronization accuracy of network testing system can reach nanoseconds.
基金supported by Guangdong Provincial Natural Science Foundation of China (7005833)
文摘It is necessary to perform the test of system on chip,the test scheduling determines the test start and finishing time of every core in the system on chip such that the overall test time is minimized.A new test scheduling approach based on chaotic ant colony algorithm is presented in this paper.The optimization model of test scheduling was studied,the model uses the information such as the scale of test sets of both cores and user defined logic.An approach based on chaotic ant colony algorithm was proposed to solve the optimization model of test scheduling.The test of signal integrity faults such as crosstalk were also investigated when performing the test scheduling.Experimental results on many circuits show that the proposed approach can be used to solve test scheduling problems.
文摘随着Internet的日益发展、普及,人们对WEB的要求越来越高,需要灵活的动态网页技术。动态网页技术ASP具有保密性好、与所有脚本语言兼容、易编写、无需编译等特点,且ASP在与数据库的连接上采用ADO(ActiveX Data Objects)技术访问后台数据库,这些深受网页制作者的欢迎。在Online Testing System中动态网页制作中采用ASP,具有一定实用价值。
