模糊PID控制在冷却水温控系统中的应用

针对上海光源冷却水温控系统中板式换热器的时变特性和系统大滞后特性,结合PID控制和模糊控制的优点,提出了以误差和误差变化率为输入信号的Fuzzy-PID复合控制器和以误差和响应时间为输入信号的模式选择开关控制器来实现冷却水温度控制策略。仿真实验和实际应用表明,该控制策略能够克服板式换热器时变特性和系统大滞后特性,对负载发生变化后能以较短的响应时间和较小的超调量使系统达到新的平衡,控制效果优于传统的PID控制。     

上海光源同步光监测系统第一面萃取镜设计

本文介绍了上海光源(SSRF)同步光监测系统第一面萃取镜的设计.设计要求从同步光中尽可能不失真地分离出可见光.设计难点在于同步光中的高能X射线会致使萃取器件发热灼损,产生形变,影响可见光成分的波前和幅度.我们通过对同步光的功率谱分析和基于ANSYS程序的受热形变分析,设计出一面带水冷系统的铍镜用以反射可见光和透射X射线,以满足设计要求.     

上海光源前端高热负载挡光器的结构设计与优化

为了有效处理上海光源前端挡光器接收的高热负载,研究了挡光器的结构设计及其优化方法。选用高导热性、高强度的GlidCop AL-15制造挡光器吸收体,采用直接水冷和掠入射结构提高其热缓释能力。以对流换热系数和压力降为评价指标,选用佩图克方程和达尔西-韦斯巴赫方程优化冷却水路,通过热分析得到了不同参数下挡光器的温度和热应力分析结果,从而确定了挡光器的结构设计优化参数。优化后挡光器的水路直径为6mm,水路到光照面的距离为9mm,光照面接线处圆角≥2mm,且水路与光束方向基本平行。与初始结构相比,优化后挡光器的最高整体温度和最高冷却壁温度分别下降约8%和1/4,最大等效应力降低了1/2左右,完全满足上海光源前端部件的设计要求。目前,应用优化参数设计的挡光器已应用于上海光源实际工程中。     

基于AT＆MCA的SSRF低能输运线上层应用软件设计

AT和MCA都是基于MATLAB的介于上层应用软件和底层加速器控制系统之间的加速器物理软件工具包.文章详细介绍了基于这两个软件包的SSRF低能输运线上层应用软件设计.离线及在线仿真测试以及SSRF低能输运线调束结果表明,该软件所有功能基本运行正常,软件通过EPICS与真实电源之间数据读写准确,计算结果与SSPF低能输运线各参数相符,匹配及轨道校正等功能在SS-RF低能输运线的调束工作中也起到了一定的作用.     

上海光源全局束流诊断数据仓库开发

上海光源已建成的束流诊断系统可满足光源的日常运行和机器研究需要。但由于缺少有效的事件触发处理机制,无法保存并分析运行期间突发的全局轨道扰动、BPM故障和DCCT噪声等异常现象。为解决以上问题,本文在现有束测系统的基础上开发了基于Soft IOC的全局束流诊断数据仓库。数据仓库通过在线监测加速器和束测系统的运行状况,在发现异常现象时及时发出触发信号并存储相关数据进行分析。运行结果表明,数据仓库能有效检测加速器和束测系统异常,并可用于生成束测设备置信度指标,为进一步优化束测系统和提高光源运行性能提供有效依据。     

采用图遍历算法的服务端请求伪造漏洞检测

针对基于PHP语言开发的Web应用系统,提出了一种基于图遍历算法的服务端请求伪造漏洞检测和利用方法。通过构建抽象语法树,获取每个文件的数据流信息,进而利用数据流中的传递依赖关系构造全局的代码属性图,使用图遍历算法对生成的代码属性图进行污点分析,得到污点变量的代码传递依赖路径图,最后使用约束求解的方法对路径图中的经过函数信息进行漏洞检测并生成可利用的攻击向量。实验结果表明,这种检测方式相较于传统的静态审计方法能够很好地发现服务端请求伪造漏洞,并能够自动化生成可绕过的攻击向量。     

Improving Touschek lifetime and synchrotron frequency spread by passive harmonic cavity in the storage ring of SSRF

Beam lifetime of a synchrotron is dominated by Touschek scattering.In the beamline Phase Ⅱ project of Shanghai synchrotron radiation facility,a passive third harmonic cavity is to be installed for bunch lengthening and instability suppressing.In this paper,the beam dynamics of the cavity is investigated.The parameters of passive operation are optimized to cancel the slope of RF voltage and lengthen the bunches.The Touschek lifetime increases are estimated for optimum and non-optimum voltage flattening.A tolerance of the operation is studied in case that there is a shift on detuning angle.The effect caused by reduction in harmonic voltage generated by lengthened bunch distribution is also estimated using iteration method.An increase in synchrotron frequency spread due to nonlinearity of the voltage giving to the bunch is found by using tracking simulation.This spread can help in damping coupled bunch instability through Landau damping.     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

Low-alpha optics design for SSRF

<正>In this paper,short pulse radiation in Shanghai Synchrotron Radiation Facility(SSRF)is generated by the low momentum compaction factor(α_C)optics,and three kinds of the low-α_C optics are found,with the very lowα_C being adopted by reducing dispersion in the straight section to negative value in the SSRF.Energy acceptance is selected as objective functions in nonlinear optimization rather than the second orderα_C or other nonlinear driving terms.The optimal result is improved step-by-step by randomly setting harmonic sextupole strengths.Two optics modes,i.e.low positiveα_C and low negativeα_C,are analyzed.In order to get a large energy acceptance and only one stable point in longitudinal phase space,the low negativeα_C optics is taken as an operation mode for the short pulse radiation in the SSRF.     

Monitoring the charge bunch-by-bunch for the SSRF storage ring:Development and application

Bunch charge uniformity controlling is very important for top-up operation of the storage ring. In order to monitor filling pattern and measure the bunch charge precisely, a PXI waveform digitizer-based data acquisition system has been developed to retrieve bunch charge information from BPM pickup signals. An effective sampling rate is extended to 400 GHz by waveform rebuilding technology, which overlays multi-turn data into single turn with real time sampling rate of 8 GHz. An on-line evaluation indicates that resolution and linearity of the charge measurement are better than 0.5% at input range of 0.5-12 nC.