Advanced Materials Research Vols. 712-715

Abstract: The paper discussed the main design philosophy of alarm controllers in detection and alarm systems for combustible and toxic gases according to content of national standard, GB 16808-2008. The content of this paper is mainly divided into two parts, program of software and development of hardware. In addition, some key points and problems which should be paid attention to in design and development stage of new product are summarized, including EMC performance, immunity to environment interference and so on.

Abstract: Eddy current testing is now a widely used Non Destructive Test (NDT) method for determining the size of cracks in metallic structures. The probability of detection (POD) is a key metric in assessing the effectiveness of nondestructive evaluation techniques. The POD analysis using common method is studied and modified. The eddy current sensor effective is discussed to support the proposed method. The new method is shown better result in improve the POD than the common one. The estimates of POD as a function of crack size will be valuable for future model-assisted POD study.

Abstract: According the problem of defect type discrimination and quantitative detection of defect depth in eddy current testing (ECT) on the conductive structure defect. The text proposes a RBF optimization algorithm based on system subtractive clustering (SISCA),first of all, according to the likelihood of the data ,it uses the system clustering method to estimate the number of clustering center, and improves mathematical model of subtractive clustering to determine the clustering scheme, then takes the minimum of the largest distance variance in the cluster as evaluation index to obtain the optimal clustering information to provide the critical initial value for training RBF network. The facts proves improved RBF algorithm takes higher accuracy and more effectiveness in the experiment of ECT.

Abstract: Eddy current testing technique has been widely used in a variety of fields, many researches have been done in quantitative estimation in conductive structure. In the actual use of ECT system, lift-off effect is an inevitable factor which is still a challenging task. Hence, the objectives of this study are to introduce a novel model-free method Support Vector Regression optimized by Particle Swarm Optimization (PSO-SVR) to estimate the surface defect with variable lift-off. Experimental validation carried out that the proposed method had a good performance in surface defect estimation with lift-off effect.

Abstract: Nowadays, the issue of food safety has become the focus of the whole society. So we need to establish an efficient, accurate and non-destructive detection technology of food safety as soon as possible. Terahertz wave ranges between microwaves and the infrared light in the electromagnetic spectrum, which has a very important research value and a good application prospect. As a new detection technology, Terahertz time-domain spectroscopy can meet the needs of non-destructive detection of food safety. In this paper, we use THz-TDS technology to measure and analyze the THz spectra of flour brightener. By measuring and analyzing the pure substances and mixtures of flour and brightener, we preliminary prove that THz technology can be used in qualitative and quantitative detection and analyzing of flour quality.

Abstract: Fluid power transmission and control, fuzzy control and related fault-tolerant control technology, which have been widely used, as the core of control and power transmission. At the same time the hydraulic system is developing to be large-scale and complicated, which makes the high reliability and safety more and more important. There is no doubt that the researches conducted in the hydraulic system of fault tolerant control field will create significant value in application. This article summarizes the Knowledge Modules of Hydraulic Fault (KMHF), which is the necessary premise to carry out researches on the fault-tolerant techniques based on Knowledge Modules of Hydraulic Fault. On this basis, this article takes the pressure-flow compound control module as an example, introduces the principle design, analyzes the static and dynamic of their pressure /flow control unit. Especially, the paper employs the simulation tools-AMESim, to conduct simulation calculation and analysis of the pressure perception control module which is based on Knowledge Modules of Hydraulic Fault. Besides, this paper has carried out experiments on the automatic hydraulic drill platform to research the test fault-tolerant control performance of the pressure perception control module. The simulation and test results show that the new fluid fault-tolerant technique based on Knowledge Modules of Hydraulic Fault proposed in this article practically improves the reliability and safety of the hydraulic system, and has great value for application.

Abstract: Synthetic aperture focusing ultrasound imaging technique used signal processing method to analysis ultrasonic echo data. It let the performance of transducer with small apertures be as well as the transducer with large aperture. It can still obtain high azimuth resolution image and form three-dimensional image, when it was operated at lower operating frequency. This paper describes the history and the theory of synthetic aperture focusing ultrasound imaging technology. It also contains the development of the synthetic aperture focusing ultrasound imaging technology in China and at abroad. And lots of excellent synthetic aperture focusing ultrasound imaging algorithms were listed in this paper. We analyzed the deficiencies and problems of the existing ultrasound focusing algorithms. And we made forecast about the development of synthetic aperture technology in nondestructive testing.

Abstract: In the paper, researched a fault diagnosis system which is used in the ICM (Intelligent Coiling Machine)successfully, it is a kind of fault diagnosis system that uses compactwavelet neural network wavelet neural network as the intelligent core and has the PFA(Principal Factor Analysis) pretreatment function. Through innovative designing and carefully plotted monitoring ways and methods in the system, as a result the fault diagnosis rate of accuracy is high, fault-tolerant ability is strong, the processing speed is quick, and the system work safely and reliably.It has achieved the anticipated goal and the effect.

Abstract: Base on the force balance theory, a model is set up to analyze the hydrostatic guideway with the closed four pads. Each oil pocket force is calculated, which is caused by the gravity center and the driving center of a slide carriage. According to the hydrostatic theory, the oil film variation that is generated during the movement is obtained. It is composed of linear and angle errors. The results show the driving force center and the geometrical center of the slide carriage have an effect on each oil film thickness, as well as the size and the location of the driving force. The article states their relationship and supplies the theoretical foundation for the design and employment of the hydrostatic guideway.

Abstract: Unexploded Subprojectiles is a serious and prevalent environmental problem currently facing us. In this paper, the safety of Unexploded Subprojectiles detection and the detection objective and detection environment were analyzed. the Unexploded Subprojectiles detection experiment was studied. The research indicates: there is a certain effect to detect Unexploded Subprojectiles where is in the non-magnetism soil and under shallow earth. But there is big influence in depth of hidden objective, and the dimension of real objective cant be reflected.