Advanced Materials Research Vols. 562-564

Abstract: In this paper, a method for GIS equipment fault diagnosis by the analysis of volume fractions of the derivatives of SF6 gas inside GIS equipment is presented. For the method, based on the differential spectra method, a neural network model and the particle swarm optimization are used for training analysis of infrared spectra, to realize the quantitative analysis of specific derivatives. The experimental results show that the prediction errors obtained by particle swarm optimization training are markedly superior to prediction errors obtained using the traditional method.

Abstract: In recent years, with the research intensity of machine vision in universities are increased ceaselessly, the achievement in machine vision’ field is gradually applied to all walks of life. This paper mainly discusses how the theory of machine vision applied in the practical measurement, and develops the overall measurement platform. Through the program operating in the computer, finally realizes the control of platform operation. It can collect multiple images; what’s more realize image processing and world coordinate calculation, providing a platform for the future research and application.

Abstract: Aimed at the problem of lacking quantitative testing method for overspeed protection switch (OPS) in hoisting machinery during its regular inspection, the paper developed a testing instrument. The instrument consisted of a testing stand and a control system. The testing stand with a variable-frequency motor was used to install OPS. The control system include sensor, hardware circuit and software program, it can collect and process both speed signal and switching action signal of OPS and kept the speed value of switching action. The speed of switching action was just the quantitative testing value for OPS. By compared the testing value and the setting speed value determined by the standard, the qualification of OPS can be evaluated. Application result demonstrated that the testing instrument can test the speed value of switching action of OPS correctly. Thus, the instrument provided a quantitative method for inspectors to judge the qualification of OPS.

Abstract: In order to solve the online measurement problem of paper moisture rate technical specification, the moisture rate measuring technique based on the infrared spectroscopic analysis is researched in this paper. The basic law on the spectral absorption of medium is expatiated and the problems applying the law to the moisture ratio measurement are also analyzed. The key technology that can realize the ratio on-line measurement by means of two spectral lines (measuring spectral line and the reference line) is explored. The measurement project is designed and the role of the main functional module in the project is discussed. The corresponding experimental research is carried out. The analysis results are given.

Abstract: A dynamic characteristics test and analysis system for CNC machine tool is developed based on C++/Qt platform and NI-DAQmx data acquisition driver. The function modules include hammer experiment, signal continuous acquisition, spectral analysis, frequency response function analysis and signal coherence analysis, etc. The analysis results provide the basis of dynamics characteristics simulation and cutting parameters optimization. The system can be also used to analysis the vibration of the cutting process. Spectrum analysis modules help to assess the cutting stability and diagnose problems. Experiments show that the system has good accuracy and efficiency while the size and price are decreased compare with traditional equipment.

Abstract: A number of multi-phase motors can be series-connected and driven by a single inverter via the appropriate phase transformation rules, and all motors in series-connected can be independently controlled . In this paper, the working principle of two six-phase permanent magnet synchronous motor series-connected system is proposed, the vector control strategy of id=0 and the carrier-wave modulation PWM technology are adopted to make the decoupled running of the two motors. Simulation of the two motors series system is obtained based on Matlab/simulink. The feasibility of the series system is proved by analysis the independently operating of one motor when the speed of the other motor is changed.

Abstract: Separating flame image from background is a precondition and necessary link for identification for recognition algorithm. In current application, the Otsu method is a simple, effective and threshold value selection method suitable for real time processing, but the limitation of this method is it depends too much on the image pattern of “double peak histogram”. To overcome the weakness and shortcoming of Otsu method, this paper puts forward a new method based on grayscale integral projection, for flame image segmentation and positioning. Experiments have proved that this method not only can separate a flame image from background correctly, but also can position the center of a flame image quickly so as to provide the important criterion for dynamic recognition of flame image.

Abstract: The structure and working principle are introduced in the paper. Based on the physical model of key parts to roto-jet pump which is set up in Gambit, the 3-D steady flows numerical simulation has been implemented by means of Fluent under design operating conditions. This method could avoid the error in simulating single part of the pump. The result shows the interflow distribution of the pump, the difference effect is very well after installing short blades on impeller. the shape of collecting pipe has little impact on the pressure within rotor cavity and the vertex band is apt to form in the corner of the collecting pipe inlet. By analyzing the energy losses between two different installed types of roto-jet pump. The result shows that the energy loss of rotor cavity in right-closed impeller pump is more than in the left-open impeller pump, but the effect of impeller pressurization in left-open impeller pump is not well, the energy loss caused by collecting pipe is almost the same in the two different pumps. The analyzing results can provide some proposals for structure reforming, performance and efficiency improving.

Abstract: A new manufacturing method of spiral hot bending process for the end sheet of tubular pile was introduced in this paper. A three-dimensional (3-D) thermal-mechanical coupled elastic-plasticity finite element model was setup to simulate the hot bending process, and then, the section deformation mechanism from hot bar by rolling to the end sheet has been investigated from the simulation results. The industry manufacture conditions show that the efficiency and quality has been highly improved by the spiral hot bending process. The thickness variety along the radial direction of the workpiece has also been analyzed, the moment and force during the hot bending was also presented in this paper. These conclusions obtained can guide for the forming technology making for both the end sheet of tubular pile and other ring parts.

Abstract: This paper presented a face detection method for the color image using pulse coupled neural network (PCNN) and skin color model. The color image which is processed well through light compensation is converted from RGB to YCbCr color space, then the skin area are divided into sub-block, and skin color segmentation is made for the image in YCbCr space. Finally, we use PCNN to extract all sub-block ignition time sequence, and calculate various sub-block difference degrees between target face and the tested image, if the difference degree is the smallest, then the target face himself is the same person. Experimental results show that the proposed method has higher accuracy and robustness, can obtain satisfactory detection effect.