Papers by Keyword: Control Parameter

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Authors: Gabriel Gorghiu, Paul Ciprian Patic, Dorin Cârstoiu
Abstract: In the last period, the quality and productivity of arc welding operations increased more than ever, especially in the areas that require high technology, represented mainly by the aerospace and nuclear industry, which led naturally to automation and robotics welding operations. The paper proposes a fuzzy system for the establishing of the main control parameters (welding current and welding speed) function of two important input parameters (plate thickness and diameter of the non consumable tungsten electrode). In this way, one of the actual modeling techniques (fuzzy logic) can be extended in welding technologies as an alternative tool, being particularly attractive for automated and robotized welding processes.
Authors: Hu Qiao, Hai Cheng Yang, Rong Mo, Dong Liang Zhang
Abstract: In order to solve problems concerning the complex module replacement and positioning difficulties in the modular design process, the control-model which reflects the main structure of product is established. Control-model bases itself on the product’s absolute coordinate system, and by establishing datum plane and sketches it reflects the main structure of products. According to the relationship between modules, modules can be partitioned into main-modules and attached-modules. The main- and attached-modules established by using control-model as seed file contain relevant information of the control-model, therefore the method of modules’ rapid positioning by comparison and updating as well as module change strategies can be used to realize modular design process without assembly constraints. Finally, taking a certain type of tank semi-trailer as an example, this paper makes detailed explanation about the modular design method based on control-model.
Authors: Yan Juan Ren
Abstract: For the same controlled process, different controller is radically different in control effect. Aimed at the puzzle of being difficult to select the controller for the incompatibility among control performance index, the paper proposed a sort of improved PSO algorithm. Based on the construction of objective function in multi-performance index parameter, the algorithm could quickly search and converge to control parameter in global optimal extremum corresponded to each controller and single out the controller through performance comparison excellently. In the paper, it took the controller selection of wastewater treatment system as an example, designed the algorithm of multi-modal HSIC controller of DO parameter, made the experiment of system simulation, and the simulation demonstrated that the HSIC controller could be stronger in robustness and better in dynamical and steady control quality compared with improved PID controller. The research result shows that it is reasonable and applicable to optimize selection of controller.
Authors: Xing Gao Li, Da Jun Yuan, Hao Hu
Abstract: The choice of reasonable parameters of EPB shield tunneling in weathered granite ground is of great importance to reduce tunneling-induced effects on existing tunnels. Combined with the practice of the EPB shield tunneling below existing interval tunnels from Kexueguan station to Dajuyuan station of Shenzhen metro line No.1, the method of design and regulation of main parameters including the earth pressure in excavation chamber, the ground conditioning, the volume of the discharged soil, the grouting control and the advance speed, of the EPB shield tunneling are studied. The practice of the below-crossing shows in the weathered granite ground, it is reasonable that the earth pressure in excavation chamber is taken as 0.15-0.2 mpa, and that FER, FIR and CF of foam are taken as 8-15, 30-50% and 3-5% respectively, and that the amount of synchronization grouting is 8-10 m3 per ring along with the injecting pressure of 0.3-0.4 mpa, and that the second phase injection is employed to control the further settlement of existing tunnels when necessary, and that the advance speed is taken as 8-10 mm/min, and as steady as possible. Meanwhile, adjustments according measured data must be performed when necessary. Moreover, the real-time monitoring and a collaborative-work environment among the Parties involved in project are also very crucial to facilitate the risk management of the below-crossing.
Authors: Ji Wei Cai, Yu Sun, Cheng Zhi Zhang, Jing Li
Abstract: Part of free water in fresh concrete bleeds out and results in problems of hardened concrete. In order to explore the determinant factors to control bleeding process and effecting mechanism, a series of mix samples in various water-to-cement ratios and sand ratios for different slump requirements were prepared to test their bleeding rates. Then the parameters to control bleeding process of fresh concrete and their influencing factors were investigated by regression analysis. The results reveal that percent volume of powder in mix (βp) and the ratio of powder to voids between sand particles (p/v) are key factors to control bleeding speed, and p/v also controls the dormant time of bleeding. The sand ratio influences the bleeding process by changing the value of p/v. Both βp and p/v have their critical values and optimum ranges. When p/v=0.78~0.87, the bleeding can be regulated to Late-Slow type with the least harm to properties of hardened concrete.
Authors: Min Yuan Huang, Zong Ren Zou
Abstract: Using the finite element software ANSYS to analyze dynamic characteristics of external prestressing structure, reasonable control parameter, as well as external prestressing reinforcement joints of security, the main research contents and results are as follows: Dynamic performance analysis is about variation law and internal feature. With the increase of external prestressing, on the contrary, the natural vibration frequency will reduce. However, external prestressing effects on the structural dynamic performance improvement that is not obvious in general. Based on sensitivity analysis, control parameter of external prestressing reinforcement curved beam must be analyzed and the reasonable value range of sensitive control parameter can be found. For the control parameter of external prestressing process, its reasonable control parameter’s range should be about 6% in the theoretical calculation. While simulating of anchoring system, local force on anchoring system must be analyzed finely and accurately. A comprehensive understanding should be mastered on variation law, which is about the internal forcing and stress response of special area. The setting of anchoring device shall be arranged at 1/3 place of original prestressing position. To ensure the safety, it should guarantee the mechanical continuity of anchor joints.
Authors: Xiang Qian Hu, Xue Tun Zhao, Hong Gang Huang, Jun Ting Long
Abstract: Based on the precast pile foundation field test of the power plant, the distribution and dissipation of the excess pore water pressure induced by the construction of the precast pile are first analyzed after the plastic drain board driven in the soft ground. Then the influence factors of the distribution and dissipation of the excess pore water pressure are presented. Subsequently the quality problem of the pre-date driven pile caused by the construction of the precast pile is studied. The main control parameters of the precast pile construction under the complicated condition are provided, which will provide a reference for such similar projects.
Authors: Min Zhou, Zheng Lin Ye, Guo Hua Peng, Yun Qing Yang, Hong Chan Zheng
Abstract: In order to overcome the difficulties in representation of developable surfaces utilizing traditional approaches, and resolve the problems in adjusting and controlling the position and shape of developable surfaces that often faced in Engineering. In this paper, we propose a directly explicit and efficient method of computer-aided design for developable surfaces based on triangle-B spline. The shapes of developable surfaces can be adjusted using a control parameter. Meanwhile, we show that the techniques for the geometric design of developable surfaces in this paper have all the characteristics of existing approaches for curves design. The algorithms are explained in detail, and demonstrated with the examples in the paper.
Authors: Min Yuan Huang, Zong Ren Zou
Abstract: With continuous development of the structural engineering, a perfect theoretical foundation and construction means is the key to its development. Combined with characteristics of the curved beam, it will be closely integrated together with external prestressing technology. The associated design and construction research can be carried out, in order to fully meet the need of the prestressing development. In this paper, the advantages of external prestressing curved beam was studied, and relevant contents are as follows: reasonable adjustment of external prestressing tendon’s diameter makes the structural force to become more uniform and prevents inappropriate use to tendon; reasonable external prestressing tendon and anchorage is the premise of good structure connection. The crucial problems should to be solved are the lower anchor position and stress concentration treatment. Considering the security need of prestressing curved beam’s tendon connection, attention should be paid not only to its materials and mechanical properties, but also to the convenience of construction. The external reinforcement work of prestressing curved beam is to ensure reasonable control parameters, as well as to ensure the optimal design of reinforced construction. As for the technical grasp on the theory and construction of external prestressing curved beam structure, it will make them have broader development space.
Authors: Kai Zhang, Zhan Yong Yao, Qing Sen Shang, Xiu Guang Song
Abstract: To study the feasibility of impact compaction on the foundation and subgrade compaction in Yellow River flooded area and explore construction process and control parameters that could ensure good compaction results, experiment was conduct on impact compaction. By way of detecting the influence of impact compaction on settlement, moisture content and degree of compaction in different construction technology to analysis the feasibility of impact compaction on the foundation and subgrade compaction in Yellow River flooded area. By evaluating the effect of compaction of different construction techniques, appropriate construction technology and control parameters of impact compaction on foundation and subgrade in the Yellow River flooded area was summarized. Research results showed that impact compaction had a good compaction effect on foundation and subgrade in Yellow River flooded area. For foundation compaction, discontinuous impaction construction should be adopted and control parameters should use degree of compaction and settlement and the best impaction times should be 12 -14 times. For subgrade compaction, the thickness of the loose layer should be 80cm and the best impaction times should be 25-30 times.
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