Control of floor heaves with steel pile in gob-side entry retaining

A new approach named as steel pile method is innovatively proposed in this study to control severe floor heaves in gob-side entry retaining. It is required that the steel piles be installed in the floor corners with a certain interval before the influence of the dynamic pressure induced by current panel extraction. Using numerical simulation and theoretical analysis, this study investigated the interaction between the steel piles and the floor rocks during the service life of the steel piles, and revealed the mechanism of the steel piles in controlling floor heaves. The effect of the steel pile parameters on the control of floor heaves was presented and elaborated. It is found that the effectiveness of the steel piles in controlling floor heaves can be enhanced with greater installed dip angle, longer length and smaller interval of the steel piles.Compared with traditional methods, e.g., using floor anchor bolts and floor restoration, the advantages using steel pile were successfully defined in terms of controlling effect and economic benefits. It is hoped that the proposed method can contribute to the development of gob-side entry retaining technique.     

自动简易擦窗器的设计

现实生活中,已经有多款用于擦洗玻璃的装置面市,但因这些产品或制造成本比较高昂,或使用范围有限,甚至效果不好,使其局限性比较大,难以得到推广。针对这些问题,本设计采用51单片机来控制自动擦窗器的电机及喷水装备以达到擦洗玻璃的目的,其效果明显,装置简单,成本较低,利用价值大,有着广阔的市场前景。     

浅析油田外部市场廉洁风险的有效防控

以规范权力运行和监督为主线,对油田外部市场廉洁风险防控情况进行研究,有针对性地制定和实施预警预防、制度规范、监督制约等防控措施,可以规范油田外部市场,廉洁从业环境,促进企业健康有效对外发展。     

浅谈如何推进油田廉洁风险防控工作机制的建立

为了深入开展廉洁风险防控工作,作为中国石化企业都应该积极探索切实可行的廉洁风险防控机制,通过全员清权查险,全面制度预防,建立防控机制,初步形成"权责清晰、流程规范、风险明确、预警及时、监控有效"的特色廉洁风险防控体系,有力促进企业廉洁风险惩防体系的建设。     

超精密加工伺服系统滑模控制技术研究

为实现超精密加工伺服系统高精度跟踪控制，建立了交流水磁同步电机伺服系统模型，研究了带扰动观测器补偿的滑模变结构控制方法，仿真结果表明，该控制策略有效地抑制了负载扰动引起的抖振，对参数波动也有较强的适应能力，可以有效地提高系统的跟踪特性。     

Evaluation of form data using computational geometric techniques—Part I: Circularity error

The present work deals with evaluation of form error from the measured profiles obtained using a form tester, namely roundness/cylindricity measuring instrument. In Part I, details of circularity evaluation are presented. Due to eccentricity in component setting and radius-suppression inherent in the measurement, circularity error has to be evaluated with reference to a limacon. A computational geometry-based algorithm is proposed for establishing minimum circumscribed, maximum inscribed and minimum zone limacons. A new type of control hull for directly constructing equi-angular diagrams and a new procedure for updating are introduced. Validation has been done with bench-mark data set and corresponding results available in the literature. Being geometry-based algorithm, it is simple to follow and each iteration can be visualized and interpreted geometrically. On comparison with simplex search method, the proposed algorithm is found to be computationally efficient in terms of accuracy and time taken. The proposed methods can be easily implemented in computer-aided roundness measuring instruments. Extension of this work for evaluation of cylindricity error has been dealt in Part II.     

TIG焊熔池外激谐振与熔透的关系

薄板TIG 焊时,利用脉动电流引起熔池振荡,当脉动电流与一定尺寸熔池自然振荡频率相同时,则熔池产生谐振,造成电弧长度及电弧电压有较大的往复变化。对电弧电压变动部分进行滤波,放大并用计算机采样,发现当熔池谐振时,电弧电压变动部分达到最大幅值,谐振后幅值很快衰减。本文以熔池谐振信号做为熔透信息进行熔透控制,给出了脉动电流电源,计算机检测系统。研究了熔透信号的变化规律及影响因素,在定点电弧及对接焊时,熔池尺寸与熔池谐振频率有较好的对应关系;以焊接电弧做为传感器,用熔池谐振频率控制熔透及熔池尺寸,有很好的重复性及较高的精度,这对解决熔透闭环自适应控制有很大的实际意义。     

自动纸盆喷涂机系统的研制

以工控机为核心,应用宝德运动控制卡NextMoveES,研制了一种简单可靠的自动喷涂机系统.该系统是针对扬声器纸盆表面自动喷涂作业开发的专用自动化设备,能完成各种形状纸盆表面的自动喷涂.该机已投入实际生产,使用效果表明:该系统操作简单、喷涂质量稳定,工作效率较高.     

自动焊机监测与参数化曲线控制系统设计

设计了自动焊机的监测与参数化曲线控制系统,以可视化方式为工艺人员改变焊接过程的控制参数提供了便利,该控制系统的数据库的数据存储与查询功能为工艺人员进行离线工艺分析提供了大量的数据,且该系统与焊机的数控系统密切配合,实现了焊接自动生产线的可靠监控.