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Shen W.,Sichuan Engineering Technical College
Advanced Materials Research | Year: 2011

Data mining is a variety of analysis tools using the data found in the mass relationship between model and data technology, and relationships of these models can be used to predict. Organically with the combination of expert system, can solve the problem of automatic acquisition of knowledge. It from a large number, incomplete, noisy, fuzzy, random data mining the hidden decision-making has important reference value to generate the information. Data mining technology used in machinery fault diagnosis system, the scene of large quantities of raw data into valuable knowledge for specialists to explore the information they are interested in, but also describes the evolution trend of mechanical malfunction, the expert decision-making support information. And, after years of development, data mining technology has matured and widely used. The purpose of this study is that data mining technology used in machinery fault diagnosis and to study its feasibility. If applicable, must be able to open up a mechanical fault diagnosis, a new diagnostic method, which greatly promote the development of mechanical fault diagnosis technology. © (2011) Trans Tech Publications, Switzerland.

Yin J.,Sichuan Engineering Technical College
Journal of Convergence Information Technology | Year: 2012

PID controller is one of the earliest-developed control strategies, and genetic algorithm is an iterated self-fitness probability searching algorithm taking example by the natural selection of the living beings and natural genetic mechanism. The paper puts forward a kind of optimization design for PID controller parameters based on genetic algorithm. Genetic algorithm simulates the evolution steps of living beings, introduces the selection operator, crossover operator and mutation operator into the optimization procedures. The selection is to optimize the population by choosing the individuals of higher adaptability from the paternal population; the crossover is to randomly select some to cross to gain the new samples by randomly choosing a pair of individuals from the population, which can amplify the hunting space; the mutation is to avoid of the important genetic information missed by the selection and crossover, which can develop the searching efficiency and the global searching ability of GA by operating the individual according to its location. Compared with some conventional adjusting methods, GA is easier and has more accurate adjustment to confirm the optimization direction by the fitness function. The paper uses the genetic algorithm to optimize the PID parameter of the speed control system of the crude oil engine, and has a simulation research on the system. The experimental result shows that genetic algorithm is a simple and high effective optimization algorithm, and it obviously improves the dynamic performance of the system comparing with the traditional methods.

Han X.,Sichuan Engineering Technical College
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2013

Although there are many factors influencing die-casting die failure, thermal stress and mechanical stress subjected in working process are main responsible for the failure. The temperature field of a die casting die from a factory was simulated to understand the key parameters influencing temperature field changes in mould. The die-casting process was divided into four stages: die casting-solidification, open mold-pick up, spraying - clamping, clamping - next die-casting, and coupling numerical simulation for thermal stress and mechanical stress was conducted. Through analyzing stress changes at different area from different cross-sections, stress change mechanism was presented at different processing parameters, providing a data reference to predicting service life of mould.

Li Z.,Sichuan Engineering Technical College
Proceedings - PACCS 2011: 2011 3rd Pacific-Asia Conference on Circuits, Communications and System | Year: 2011

Steam pressure is a key point to keep the steam pressure constant in various operation situations. Considering steam pressure with the time delay and uncertainties, the sliding mode predictive control was used to design the controller. The predictive control was used to deal with time delay, the sliding mode control was used to deal with the uncertainties. And the predictive control can reduce the chattering phenomenon of sliding mode. Ths simulation results show that the proposed algorithm can largely imporve the system response performance compared to the single generalized predictive control. © 2011 IEEE.

Xu J.,China Academy of Engineering Physics | Zhang Y.,Sichuan Engineering Technical College
MATEC Web of Conferences | Year: 2016

For the Free-Piston Stirling Engines (FPSE) control system, a three-phase bridge circuit is reused as the system output about rectifier and start inverter. When FPSE system is in the power stage, the double closed loop control strategy and optimization algorithm of PI control parameters is adopted to ensure the highest system transmission efficiency under the requirements of the system output power and guarantee the stability of the running system. The simulation results prove the effectiveness of the above research content. © 2016 Owned by the authors, published by EDP Sciences.

Shen W.,Sichuan Engineering Technical College
Advances in Intelligent Systems and Computing | Year: 2013

According to the teaching objectives of vocational CNC machining process design background, performance analysis to determine the problem and determine the design criteria of effective teaching objectives by clarifying teaching objectives, the goal of teaching is also constant feedback to refine and improve. © 2013 Springer-Verlag.

Chen J.S.,Tsinghua University | Su G.D.,Tsinghua University | Xiang S.B.,Sichuan Engineering Technical College
Science and Technology of Welding and Joining | Year: 2012

Extracting single pixel wide paths is the core image processing problem in many vision based welding seam tracking applications. Traditional techniques such as edge detection and image thinning may not be effective for solving this problem on low quality welding images polluted by process noises. Based on the understanding of the prior knowledge about the welding images, we present in this paper a welding seam tracking method using the image seam extraction technique. Owing to its optimisation nature, the proposed method is robust to strong image noises caused by environmental factors such as uneven illumination, light interferences and welding spatters. In addition, the proposed method is of low time complexity and is highly adaptive to different types of welding images. Experimental results on a variety of welding images validate the effectiveness and efficiency of the proposed method. © 2012 Institute of Materials, Minerals and Mining.

Shu-Yan L.,Sichuan Engineering Technical College
International Journal of Digital Content Technology and its Applications | Year: 2012

This paper proposes a fuzzy adaptive watermarking algorithm based on DCT domain. Combining the visual masking properties of human visual system (HVS) and the characteristics of the original images, this algorithm has helped design a 2-order fuzzy controller based on reasonable fuzzy logical principle to decided the watermark embedding strength, thus to make the embedded watermark strength be adaptive to the original image. A large number of experimental results have verified the fact that, with the insurance of the quality of watermark images, this algorithm is of distinguished robustness in processing some common image and preventing noise interferences. The algorithm is the first proposed one which can be applied fuzzy set theory in the digital watermark technology, which is a new digital watermark method with practical value, as well as great potentials in application.

Yin J.,Sichuan Engineering Technical College
International Journal of Digital Content Technology and its Applications | Year: 2012

The paper researches on the design of controller of doubly-fed induction generator. The paper establishes dynamic mathematic model for doubly-fed induction generator based on the basic theory of electro mechanics. According to the nonlinear character of its mathematic model, doubly-fed induction generator based on fuzzy control of TS-PID is proposed. The theoretical research has been made on normal PID control and TS-PID algorithm, and these two control methods are simulated by introducing them into the active power control of doubly-fed induction generator on the basis of mathematical modeling. The experiment result shows that TS-PID fuzzy control has wider robustness and stability compared with the normal PID.

Yang L.,Sichuan Engineering Technical College
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2016

The surface of GH141 superalloy was processed by laser shock processing (LSP), and residual stress distribution was tested with X-ray diffraction (XRD) before and after the impact treatment, meanwhile, the fatigue crack was observed. Experiment results show that the residual tensile stress of GH141 superalloy reaches up to 200 MPa before impact treatment. After a LSP, residual stress is converted to compressive stress with fluctuations in -400 MPa and hardness is increased by 20%~25%. By comparing the fatigue crack before and after LSP, it is found that the fatigue crack is reduced significantly after LSP, which shows that the technique can reduce effectively the fatigue crack initiation, and improve the fatigue life. © 2016, Journal Office of Special Casting and Nonferrous Alloys. All right reserved.

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