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1.
沥青摊铺机找平系统的性能直接影响到公路施工质量。本文简要介绍了沥青摊铺机找平系统,着重叙述了声控、RSS激光扫描、CAN总线和数字式控制器四大类典型自动找平系统。  相似文献   

2.
针对二维及二维以上模糊控制器存在的缺陷,设计了一维糊PID控制器。该控制器采用“一维--三维”映射关系的模糊推理机,实现了P、I、D三个控制分量独立不相关的调整功能。通过与二维模糊控制器性能比较,仿真结果表明:一维模糊PID控制器具有相当好的系统功能特性。  相似文献   

3.
利用集DTMF双音多频、遥控、计算机等技术为一体的K-10电力载波通信协议设计自动智能配电系统.该系统的硬件结构分为总控制器、功能控制器、迷你遥控器、控制终端和电话远程语音控制五大部分,软件结构分为总控制器、功能控制器和控制终端三大模块.该系统以交流电力线为控制信号传输总线,省却了布置控制线路的麻烦,结构简单、实用性好,能够实现现代家庭、办公楼宇的电器控制、照明控制、线路配电、安全监控等方面的自动化、智能化.  相似文献   

4.
本文研究将MCS-51型单片机用于普通数控机床,通过监控程序设计,进一步完善机床性能,使该系统具有显示功能,快速点动、自动四零、自动升降频率、自动换刀、自动齿隙补偿、刀具磨损补偿,暂停等多种功能.  相似文献   

5.
本文介绍了MK9-PA8卷烟机的一种可编程序控制系统。该系统以可编程序控制器PC为核心,可实现对卷烟机工作过程的自动控制。该系统具有体积小、功能强、可靠性高、编程简单和维修方便等优点,已在数家烟厂推广应用。  相似文献   

6.
基于自动跟踪光伏发电系统,对太阳位置的检测和光电池云台跟踪控制的问题进行了深入的分析,并提出了PID-Fuzzy分段式跟踪控制方法。通过对太阳方位角的分析计算和电池板方位角的检测,设计了以太阳方位角为输入量、电池板方位角为反馈量的PID-Fuzzy控制器。该控制器可以依据角度的偏差大小来自动切换控制规律,较好地解决了系统快速性和跟踪精度的问题。并且通过Matlab仿真和实验数据对该控制器性能进行了分析。结果表明,该方法不仅降低了调节时间,而且使控制跟踪精度在原有精度基础上提高了2%,有效地提高了光电转换效率,为同类跟踪系统提供了可行性方案。  相似文献   

7.
船舶直线航迹控制的鲁棒自适应非线性设计   总被引:3,自引:0,他引:3  
针对船舶航迹控制非线性系统模型中存在的不确定性和外界干扰的影响,提出了一种鲁棒自适应控制算法.该算法将鲁棒干扰抑制技术融入自适应反演设计方法中,使得系统的输出和所得闭环系统全局一致最终有界,而且闭环系统的控制性能可以通过适当的选择设计参数而得到保证,另外,该算法还避免了控制器可能存在的奇异值问题,在计算机仿真研究中,以大连海事大学“育龙”号实习船为设计实例,验证了所提出的控制器的有效性。  相似文献   

8.
摘要:介绍了打包机称自动称重系统的改进设计,有效地解决了原打包机电子秤自动称重系统中存在的成品包重称重问题。提出了该自动称重系统的改造方案,增加小型可编程控制器和触摸屏的使用实现原有功能,优化了打包机自动称重系统,提高了纤维生产线自动化控制水平。  相似文献   

9.
本文利用计算机仿真的方法研究具有电液比例控制的自动找平控制和特性,从而对计算机仿真在自动找平控制中的应用进行探讨。  相似文献   

10.
自动送钻实验系统的优化加权模糊控制   总被引:3,自引:0,他引:3  
针对自动送钻实验系统,设计了一种带优化加权因子的模糊控制器,以ITAE积分性能指标为寻优目标函数,通过对误差和误差变化的加权因子的优化来获得系统的最佳模糊控制规则,并将其控制效果与一般模糊控制器的效果进行了仿真比较。结果表明,一般模糊控制器作用于自动送钻实验系统时,由于超调量太大,系统难以正常工作;带优化加权因子的模糊控制器可使系统的超调量降到4%,调节时间为17s,稳态误差小于0.1%,其他性能指标均满足要求,大大改善了系统的动态性能。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

14.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

15.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

16.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

19.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

20.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

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