Programmable Logic Controller Block Monitoring System for Memory Attack Defense in Industrial Control Systems

Cyberattacks targeting industrial control systems(ICS)are becoming more sophisticated and advanced than in the past.A programmable logic controller(PLC),a core component of ICS,controls and monitors sensors and actuators in the field.However,PLC has memory attack threats such as program injection and manipulation,which has long been a major target for attackers,and it is important to detect these attacks for ICS security.To detect PLC memory attacks,a security system is required to acquire and monitor PLC memory directly.In addition,the performance impact of the security system on the PLC makes it difficult to apply to the ICS.To address these challenges,this paper proposes a system to detect PLC memory attacks by continuously acquiring and monitoring PLC memory.The proposed system detects PLC memory attacks by acquiring the program blocks and block information directly from the same layer as the PLC and then comparing them in bytes with previous data.Experiments with Siemens S7-300 and S7-400 PLC were conducted to evaluate the PLC memory detection performance and performance impact on PLC.The experimental results demonstrate that the proposed system detects all malicious organization block(OB)injection and data block(DB)manipulation,and the increment of PLC cycle time,the impact on PLC performance,was less than 1 ms.The proposed system detects PLC memory attacks with a simpler detection method than earlier studies.Furthermore,the proposed system can be applied to ICS with a small performance impact on PLC.

Synthesis of Nonlinear Control of Switching Topologies of Buck-Boost Converter Using Fuzzy Logic on Field Programmable Gate Array (FPGA)

An intelligent fuzzy logic inference pipeline for the control of a dc-dc buck-boost converter was designed and built using a semi-custom VLSI chip. The fuzzy linguistics describing the switching topologies of the converter was mapped into a look-up table that was synthesized into a set of Boolean equations. A VLSI chip–a field programmable gate array (FPGA) was used to implement the Boolean equations. Features include the size of RAM chip independent of number of rules in the knowledge base, on-chip fuzzification and defuzzification, faster response with speeds over giga fuzzy logic inferences per sec (FLIPS), and an inexpensive VLSI chip. The key application areas are: 1) on-chip integrated controllers;and 2) on-chip co-integration for entire system of sensors, circuits, controllers, and detectors for building complete instrument systems.

The Designed Operation of the Machine Control System on HL-2A Tokamak

The Ethernet and field-bus communications are used in the machine control system （MCS） of HL-2A. The control net, with a programmable logic controller （PLC） as its logic control master, an engineering control management station as its net server, and a timing control PC connected to a number of terminals, flexibly and freely transfers information among the nodes on it with the Ethernet transmission techniques. The PLC masters the field bus, which carries small pieces of information between PLC and the field sites reliably and quickly. The control net is connected into the data net, where Internet access and sharing of more experimental data are enabled. The communication in the MCS guarantees the digitalization, automation and centralization. Also provided are a satisfactory degree of safety, reliability, stability, expandability and flexibility for maintenance.

Transient Stability Improvement of Power System Using Non-Linear Controllers

This paper presents the design of a non-linear controller to prevent an electric power system losing synchronism after a large sudden fault and to achieve good post fault voltage level. By Direct Feedback Linearization (DFL) technique robust non-linear excitation controller is designed which will achieve stability enhancement and voltage regulation of power system. By utilizing this technique, there is a possibility of selecting various control loops for a particular application problem. This method plays an important role in control system and power system engineering problem where all relevant variables cannot be directly measured. Simulated results carried out on a single machine infinite bus power system model which shows the enhancement of transient stability regardless of the fault and changes in network parameters.

Implementation of a new PC based controller for a PUMA robot

This paper describes the replacement of a controller for a programmable universal machine for assembly (PUMA) 512 robot with a newly designed PC based (open architecture) controller employing a real-time direct control of six joints. The original structure of the PUMA robot is retained. The hardware of the new controller includes such in-house designed parts as pulse width modulation (PWM) amplifiers, digital and analog controllers, I/O cards, signal conditioner cards, and 16-bit A/D and D/A boards. An Intel Pentium IV industrial computer is used as the central controller. The control software is implemented using VC++ programming language. The trajectory tracking performance of all six joints is tested at varying velocities. Experimental results show that it is feasible to implement the suggested open architecture platform for PUMA 500 series robots through the software routines running on a PC. By assembling controller from off-the-shell hardware and software components, the benefits of reduced and improved robustness have been realized.

Synchro Controller of Radar on FPGA

This paper mainly represents the realization of synchro controller based on the programmable logic devices FPGA by request of HF ground wave radar synchro controller under the instance of making the best of the virtues of FPGA. This design introduces the data communication between PC and synchro controller by PC Bus, which can carry the synchronous signals parameters to RAM of synchro controller, then according to the theory that the result of comparing counter value with signals parameters is the needed wave, we produce all waves HF ground wave radar needs, moreover all waves are produced time-sharing in order to save resources.

THE DESIGN OF VMEBUS BRIDGE CONTROLLER WITH SHARC BUS

Targeting at the high expense and inflexibility to realize VMEbus bridge controller by professional Integrated Circuit (IC), this paper presents a scheme of adopting CPLD/FPGA (Complicated Programmable Logic Device/Field Programmable Gate Array) to design bridge controller between VMEbus and local bus. SHARC DSP (Digital Signal Processor) bus is an example. It has functions of nearly entire master/slave interface of VMEbus, and can act as DMA (Direct Memory Access) controller and perform block transfer in DMA or master processor initiative way without length limit. External circuit of the design is very simple. In comparison with special ICs, it has high performance to price ratio and can be easily applied to local buses of other processors with quite a little modification.

Real Time Control System for Metro Railways Using PLC & SCADA

This paper proposes to adopt SCADA and PLC technology for the improvement of the performance of real time signaling&train control systems in metro railways.The main concern of this paper is to minimize the failure in automated metro railways system operator and integrate the information coming from Operational Control Centre(OCC),traction SCADA system,traction power control,and power supply system.This work presents a simulated prototype of an automated metro train system operator that uses PLC and SCADA for the real time monitoring and control of the metro railway systems.Here,SCADA is used for the visualization of an automated process operation and then the whole opera-tion is regulated with the help of PLC.The PLC used in this process is OMRON(NX1P2-9024DT1)and OMRON’s Sysmac studio programming software is used for developing the ladder logic of PLC.The metro railways system has deployed infrastructure based on SCADA from the power supply system,and each station’s traction power control is connected to the OCC remotely which commands all of the stations and has the highest command priority.An alarm is triggered in the event of an emergency or system congestion.This proposed system overcomes the drawbacks of the current centralized automatic train control(CATC)system.This system provides prominent benefits like augmenting services which may enhance a network’s full load capacity and networkflexibility,which help in easy modification in the existing program at any time.

基于PLC反渗透海水淡化控制系统的设计与开发

针对反渗透海水淡化系统工艺复杂、运维繁琐、对操作人员专业技能要求高的特点,研发了一套反渗透海水淡化控制系统。详细研究整个工艺系统中预处理、反渗透等关键工艺环节的原理及自动控制过程。从系统的硬件设计和软件开发两个方面进行详细阐述。硬件设计方面,根据装置规模和控制需求完成控制系统设备选型。软件开发方面,完成控制器及人机交互界面多套软件的开发。该系统成功应用于高校反渗透海水淡化教学实践课。应用结果表明:该系统设计合理、操作界面简洁方便,在稳定安全运行的同时可实现教学培训、故障处理等目的。该系统在提高海水淡化操作人员专业技能的同时,也对高校创新其他专业的实操培训课程提供了借鉴和技术支撑。

基于5G多接入边缘计算的云化PLC系统架构设计与应用

随着工业控制系统对柔性化、扁平化的要求不断提升,以PLC为构建基础的传统工业控制网络在大规模接入、算力提升和部署灵活性方面均受到限制.针对这些问题,融合5G网络和边缘计算技术,设计了基于5G多接入边缘计算的云化PLC系统架构,阐述了该架构的运行机制和所涉及的关键技术;在此基础上,进行PLC系统的云化部署和调试,实现了工业现场、企业数据中心、5G网络和边缘网络的集成;最后,通过在某汽车制造公司产线改造过程中的应用,验证了所提架构的有效性.

面向学科交叉融合的综合性实训教学装置设计与教学实践

针对工程训练实训教学装置功能单一、缺乏多学科交叉与整合能力等问题,以多种特征的物料识别与分拣为应用背景,在综合应用PLC控制技术、传感器技术、气动控制与机电传动控制技术的基础上,结合数字图像处理与卷积神经网络技术,基于树莓派与Jetson嵌入式计算平台,自主研制了一种物料特征识别与分拣综合实训教学装置。与现有同类实训装置相比,该自制实训装置具有体积小,功能多和成本低的优势。实践教学表明,将传统PLC控制与人工智能技术元素有机结合,以及将课内教学延伸至创客活动和学生第二课堂,能有效提升学生的工程认知水平和工程实践能力,体现多学科交叉、多技术融合的高等工程教育特征。

造纸机分布传动可编程控制器PCC系统的应用

PCC可编程控制器以其强大的数据处理能力、高运算速度和可靠网络连接等优势,在在造纸工业中得到广泛应用,充分发挥其优势有助于推进造纸机的智能化发展、提升造纸机的技术水平。对此,简述了PCC系统控制原理,设计了以PCC B&R 2005为主控制器、操作面板为人机界面、PROFIBUS现场总线为通信方式的造纸机分布传动控制系统,对系统中主要硬件选型与配置、系统通信方式、下位机软件设计等进行了详细说明,并基于组态王与PCC进行造纸机分布传动上位机监控界面的设计,以期提高造纸机分布传动控制系统的控制精度、实时性和稳定性。

PMSM正切趋近律无位置传感器角度补偿方法研究

在负载转矩突变的动态过程中,基于PI调节器的角度补偿方法作用时PMSM超螺旋滑模观测器(STSMO)转子电角度估算误差波动剧烈,因此依据角度估算误差的定义,建立了转子电角度补偿算法的数学模型。根据滑模控制和趋近律理论,提出了基于正切趋近律的变步长闭环角度补偿方法,选择角度估算误差的半角正切值作为角度调节步长,并通过前馈解耦得到的角度估算误差正余弦信号计算该步长,实现了对无位置传感器控制系统动态性能和抗扰动能力的改善。根据归一化灵敏度的定义,分析调节步长随角度估算误差变化的灵敏度,提出了基于归一化补偿灵敏度的系统动态性能分析方法,衡量两种补偿算法作用下系统的动态性能。计算和仿真结果表明,正切趋近律补偿方法具有更高的归一化补偿灵敏度,在负载转矩突变等角度估算误差变化剧烈的工况下能够实现更好的补偿效果,抑制估算角度误差的波动。实验结果表明,相比传统的PI补偿方法,正切趋近律补偿方法能够将突加额定转矩动态过程中角度估算误差的波动幅度降低61.9%,动态过程持续时间缩短23%,有效提升了系统的动态性能和抗扰动能力。

基于可编程序控制器和变频器的多段速控制系统

基于可编程序控制器和变频器设计了一套多段速控制系统。在分析多段速控制系统控制要求的基础上,进行可编程序控制器与变频器的硬件接线,分配可编程序控制器的输入输出地址,配置变频器的参数。设计多段速控制系统的时序图和顺序功能图,采用定时器指令为主体编写梯形图。通过调试确认,所设计的多段速控制系统能够满足控制要求,运行稳定可靠。

基于PLC的滤站自动控制系统设计

针对滤站的污水处理流程,设计基于可编程逻辑控制器(Programmable Logic Controller,PLC)的滤站自动控制系统,并详细阐述该系统的硬件设计、软件设计。通过应用自动控制系统,滤站能够自动完成污水处理流程,缩短人工时间,提高工作效率。

基于PLC的模块化可重组机器人实训平台控制系统研究

文章针对模块化可重组机器人的实训教学需求,提出一种基于可编程逻辑控制器(Programmable Logic Controller,PLC)的机器人实训平台控制系统。该系统采用模块化设计,通过PLC实现机器人的运动控制、传感反馈和人机交互等功能。为验证系统的可行性,设计一套完备的系统仿真实验,评估机器人执行机械加工任务的性能。实验结果表明,该系统能够显著提高加工精度和效率,在智能制造领域具有广阔的应用前景。

基于可编程控制器的槟榔包装控制系统设计

为解决槟榔自动包装机封口装置存在封口不牢固、包材烧穿等问题,设计了一种基于可编程控制器(programmable logic controller, PLC)技术的槟榔自动包装机封口装置控制系统,以实现槟榔包装的稳定性。介绍封口装置工艺以及控制系统结构,包括PLC、温度传感器、位置传感器、温度控制模块、伺服电机等。封口装置中温度为主要研究对象,同时为弥补传统PID(proportional-integral-differential)控制的不足,改善传统LADRC(linear active disturbance rejection control)控制参数整定困难等问题,提出一种粒子群(particle swarm optimization, PSO)优化改进型线性自抗扰温度控制器,以提高封口装置温度控制的鲁棒性和抗扰性。最后进行仿真和实验研究。结果表明:与传统PID以及自抗扰(active disturbance rejection control, ADRC)控制器相比,加入粒子群(particle swarm optimization, PSO)算法优化后的改进型LADRC方法,可以使系统输出响应、快速性增强,调节时间变短,封口装置实际包装温度误差<0.4℃。可见所述封口装置系统有效提高温度控制精度,一定程度上提升了槟榔自动包装机的生产效率。

基于LoRa无线通信的电子脉冲拦鱼器设计

针对传统拦鱼器拦截面积有限、智能化水平低等问题,研制了一种基于LoRa无线通信的电子脉冲拦鱼器。该拦鱼器使用Modbus RTU协议实现一主多从间高速、长距离无线通信,用户可根据不同水产养殖面积灵活选用机组个数、脉冲频率和脉冲宽度等参数,以适应不同水体中不同鱼类产生回避反应的能力。主机发送时序指令控制从机轮流产生两路反相带死区控制的PWM方波,控制IGBT进行快速换向,不仅效率高、安全可靠、耗能低,而且噪声小,符合当前绿色环保理念;同时利用LoRa无线通信的优势,在PLC上配备电导率、溶氧、pH和温度等传感器,可实时监测各从机点的水质信息,对用户水产养殖起到很好的辅助作用。此外,基于C#环境开发出基于物联网的智慧养殖平台,可实时监控拦鱼器的工作状态和各测点水质信息并进行故障预警。该电子脉冲拦鱼器,脉冲频率为3~12 Hz,脉宽为0.6~1.2 ms,比可控硅节电达60%,且植入了“物联网+渔业”的新观念,实现了手机或计算机远程控制。研究表明,该电子脉冲拦鱼器具有自动化、智能化、网络化等特点,能够适用于各类水产养殖的拦鱼作业。

全自动流水线式内镜清洗消毒系统设计

内镜的清洗消毒对于重复性的内镜手术而言至关重要。因此,内镜的清洗消毒需要有更高的效率以满足当前大量的内镜手术需求。为此,创新性地研发了一种基于可编程逻辑控制器(PLC)的全自动流水线式内镜清洗消毒系统。根据清洗消毒流程特点,设计了多槽流水线式结构。通过自动控制系统可完成符合国标和行标的检测、清洗、消毒、转运等流程。系统具备检修、急停和声光报警灯功能,可利用触摸屏实现信息记录和追溯。该系统能有效地提高清洗消毒效能、保证清洗消毒质量,从而缓解当下内镜使用紧缺的现状。该设计不仅提高了医疗器械的智能化、自动化水平,还对医疗设备的发展和研制具有开创性价值,因而具有广阔的应用前景。