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低压铸造液面加压系统的自适应模糊与积分控制 总被引:5,自引:1,他引:4
在分析常规模糊控制、规则自适应模糊控制和积分算法的基础上,对低压铸造液面加压系统进行了仿真试验。仿真结果表明,规则自适应模糊控制具有较好的动态和静态性能,不但具有很好的工艺曲线跟踪性能,而且对过程参数的变化有很强的适应性。加入误差连续量的积分作用时,采用分离算法,可消除稳态误差和防止产生较大的超调。本文所采用的控制规则在线自适应算法和积分分离算法相结合的控制方案为低压铸造液面加压系统的控制提供了一条有效途径。 相似文献
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文章以温等静压机压力控制系统中的比例流量阀为研究对象,设计了一种基于DSP Builder设计,FPGA实现的PID控制器.文中简述了温等静压机压力控制系统的组成原理、分析了数字PID控制算法原理、运用DSP Builder设计了PID控制模块,结合ModelSim对控制模块进行测试仿真,并通过QuartusⅡ完成综合、编译、仿真和硬件测试.仿真测试结果验证了应用FPGA实现PID控制器方法的正确性. 相似文献
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《组合机床与自动化加工技术》2017,(4)
以工程中的伺服控制系统为研究对象,提出一种嵌入比例因子的复合模糊自适应PID控制方法,即将比例因子模糊控制与模糊PID控制结合而成的复合模糊控制。首先通过MATLAB/Simulink系统工具对无干扰理想状况下的系统进行仿真与分析,然后进一步模拟真实环境下的系统运行状况,在某一时刻加入干扰信号,并将比例因子模糊控制嵌入模糊PID控制中优化算法,对控制系统不断加以改善与优化。试验结果表明,此方法比传统PID控制更具优势,能有效改善控制系统的响应时间、调节时间以及抗干扰能力,有效提高控制系统的动态性能和鲁棒性。 相似文献
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针对泵控压机液压系统卸压冲击问题,以0.6MN泵控压机为载体,结合功率键合图进行研究,推导出基于噪声声强最弱的理论卸压曲线。搭建了比例变量径向柱塞泵(RKP)模型,并推导出工作缸模型、包含动态摩擦项的修正型分段集中参数管道模型及其它单元模型;以卸压过程中最大声强值最小为目标,运用拉格朗日中值定理,推导出理论卸压曲线;通过仿真对比卸压过程中理论、指数、线性和正弦卸压曲线下的主缸和卸压管压力曲线,并在0.6MN泵控压机上进行实验研究。研究结果表明:基于键合图理论模型的仿真曲线与实测曲线吻合较好,并且理论卸压曲线具有较好的卸压效果,为减小卸压冲击提供了一种有效的新途径。 相似文献
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针对龙门移动式数控机床加工中心中单悬浮系统,文章设计了无量化优化函数和二级模糊控制器,采用优化函数来优化模糊规则表,运用插值算法来获得第二级模糊控制的连续校正量,将第一级模糊控制与第二级模糊控制叠加,构成二级模糊控制器。仿真研究结果表明,应用此控制方案对悬浮横梁进行控制,系统有较强的鲁棒性,横梁能够无摩擦稳定悬浮于给定位置。 相似文献
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Deng-Kui Zhang Guo-Qing Wang Ai-Ping Wu Ji-Guo Shan Yue Zhao Tian-Yi Zhao Dan-Yang Meng Jian-Ling Song Zhong-Ping Zhang 《金属学报(英文版)》2019,32(6):684-694
In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone. 相似文献
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After nearly two years'tense construction the first phase of industrialized base of Shenyang Research Institute of Foundry 《中国铸造》2008,5(1):63-64
After nearly two years' tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry (SRIF), located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation. 相似文献
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The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C). 相似文献
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The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel. 相似文献
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Tang Dynasty 《中国铸造》2014,(4):I0002-I0003
<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also 相似文献
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《中国铸造》2014,(5):464-466
The 9th China International Diecasting Congress & Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition. 相似文献
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《机床与液压》2014,(12)
正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc- 相似文献
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Y. Wang H.Z. Li C.N. Yu G.M. Wu I. Gordon P. Schattschneider O. Van Der Biest 《金属学报(英文版)》2007,20(3):167-170
Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony. 相似文献
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A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING 总被引:2,自引:0,他引:2
W.X. Yao 《金属学报(英文版)》2007,20(1):65-71
Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted. 相似文献