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.

Application of PLC programmable control technology in the mine pit transportation system

This paper summarizes the definition, function, and characteristics of the programmable conlrol technology, and especially analyzes the operation mode of the 750V DC traction power supply system, the protection setting the defects of the original system and the factors influencing the safety of power supply. Aimed at the equipment of the PLC programmable control system used in the mine transportation system in recent years, combining parts of the PLC programmable control system equipment used and installed in Tong Ting Coal Mine, this paper introduces the role of the PLC programmable control system and the economic benefits and safety effect.

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.

Fuzzy logic controller implementation on a microbial electrolysis cell for biohydrogen production and storage

This work presents the implementation of fuzzy logic control(FLC) on a microbial electrolysis cell(MEC).Hydrogen has been touted as a potential alternative source of energy to the depleting fossil fuels. MEC is one of the most extensively studied method of hydrogen production. The utilization of biowaste as its substrate by MEC promotes the waste to energy initiative. The hydrogen production within the MEC system, which involves microbial interaction contributes to the system's nonlinearity. Taking into account of the high complexity of MEC system, a precise process control system is required to ensure a wellcontrolled biohydrogen production flow rate and storage application inside a tank. Proportionalderivative-integral(PID) controller has been one of the pioneer control loop mechanism. However, it lacks the capability to adapt properly in the presence of disturbance. An advanced process control mechanism such as the FLC has proven to be a better solution to be implemented on a nonlinear system due to its similarity in human-natured thinking. The performance of the FLC has been evaluated based on its implementation on the MEC system through various control schemes progressively. Similar evaluations include the performance of Proportional-Integral(PI) and PID controller for comparison purposes. The tracking capability of FLC is also accessed against another advanced controller that is the model predictive controller(MPC). One of the key findings in this work is that the FLC resulted in a desirable hydrogen output via MEC over the PI and PID controller in terms of shorter settling time and lesser overshoot.

Evaluation of Selected Control Programming Languages for Process Engineers by Means of Cognitive Effectiveness and Dimensions

Different programming languages can be used for discrete, abstract and process-oriented programming. Depending on the application, there exist additional requirements, which are not fulfilled by every programming language. Flexible programming and maintainability are especially important requirements for process engineers. In this paper, the programming languages Activity Diagram, State Chart Diagram and Sequential Function Chart are compared and evaluated with regard to these requirements. This evaluation is based on the principles of cognitive effectiveness and cognitive dimensions. The aim of this paper is to identify the programming language suited best for controlling sequential processes, e.g. thermomechanical or batch processes.

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.

An Integrated Approach for Process Control Valves Diagnosis Using Fuzzy Logic

Control valves are widely used in industry to control fluid flow in several applications. In nuclear power systems they are crucial for the safe operation of plants. Therefore, the necessity of improvements in monitoring and diagnosis methods started to be of extreme relevance, establishing as main goal of the reliability and readiness of the system components. The main focus of this work is to study the development of a model of non-intrusive monitoring and diagnosis applied to process control valves using artificial intelligence by fuzzy logic technique, contributing to the development of predictive methodologies identifying faults in incipient state. Specially in nuclear power plants, the predictive maintenance contributes to the security factor in order to diagnose in advance the occurrence of a possible failure, preventing severs situations. The control valve analyzed belongs to a steam plant which simulates the secondary circuit of a PWR—Pressurized Water Reactor. The maintenance programs are being implemented based on the ability to diagnose modes of degradation and to take measures to prevent incipient failures, improving plant reliability and reducing maintenance costs. The approach described in this paper represents an alternative departure from the conventional qualitative techniques of system analysis. The methodology used in this project is based on signatures analysis, considering the pressure (psi) in the actuator and the stem displacement (mm) of the valve. Once the measurements baseline of the control valve is taken, it is possible to detect long-term deviations during valve lifetime, detecting in advance valve failures. This study makes use of MATLAB language through the “fuzzy logic toolbox” which uses the method of inference “Mamdani”, acting by fuzzy conjunction, through Triangular Norms (t-norm) and Triangular Conorms (t-conorm). The main goal is to obtain more detailed information contained in the measured data, correlating them to failure situations in the incipient stage.

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ControlLogix的PLC冗余控制系统设计

从Rockwell Automation工业控制网络的架构以及组网方式出发,阐述了基于ControlLogix5550控制器的PLC冗余控制系统的实现过程。

Design of PLC control system of RTG spreader in Qingdao Port Container Terminal

The control method of rubber tyre gantry （RTG） spreader in Qingdao Port Container Terminal is logic board control,which has many shortcomings such as expensive spare parts and high faults.This paper designs a new control system using programmable logic controller （PLC） centralized control to replace the original logic board control.The new system mainly contains complete ELME spreader control scheme design,hardware selection and PLC control program development.Its field application shows that the system has characteristics of high efficiency,low running cost,easy maintenance.

基于TIA Portal的HMI+PLC虚拟仿真探究

文章提出一种在TIA Portal软件上集成人机界面(Human Machine Interface,HMI)和可编程逻辑控制器(ProgrammableLogicController,PLC)进行虚拟仿真的方法。该方法能够在现有的硬件条件下,使学生不受时间、地点等的限制,只需要在计算机上安装TIA PORTAL软件就可以进行虚拟学习,构建控制系统,进行硬件组态、编程、控件组态、仿真运行和程序调试等。最后,以十字路口的交通灯为例,采用基于实际物理设备和基于TIAPORTAL软件虚拟仿真两种方式搭建控制系统,完成项目的设计、组态、编程、调试和运行测试。主要任务是寻找方法构建虚拟网络,将虚拟运行的PLC与HMI设备联系起来,实现虚拟设备之间和软件之间的数据传输,达到与使用实际物理设备效果相同的目的。

基于PLC的仓库灯光指引系统

基于可编程逻辑控制器(Programmable Logic Controller,PLC)的仓库灯光指引系统,即利用灯光指引位置进行定位。该系统适用性广泛,不仅在仓储行业内使用,还可以应用在其他行业,为提高效率发挥重要作用。设计灯光指引系统可以实现客户端数据采集,客户端和下位机间的数据传输,以及下位机对LED灯进行驱动等功能。最后,系统利用不同灯号的不同颜色,表示不同功能的状态。

基于PLC的气动搬运机械手自动控制系统设计

为提高气动搬运机械手在复杂工厂流水线中的运行效率,该文设计了一套基于PLC的气动搬运机械手自动控制系统。在分析通用气动机械手将物品在不同位点之间搬运的运动流程的基础上,设计了自动控制系统的硬件架构。其中包含了可编程逻辑控制器(PLC)、伺服电机、传感器和交互屏等器件,并根据气动搬运机械手的运动流程,设计了相应的软件控制程序及界面。仿真实验结果证明,所提出的气动搬运机械手自动控制系统可以稳定地完成实验预设的功能需求,自动化程度较高。

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。

PLC技术在机电一体化设备智能控制中的应用

可编程逻辑控制器(Programmable Logic Controller,PLC)是一种在自动化与工业控制系统中广泛应用的电子装置。因其高度的可靠性、灵活性及适应性,PLC已成为机电一体化设备智能控制的核心技术之一。机电一体化设备结合了电子技术、机械技术及计算技术,旨在通过智能化控制提升设备的操作效率和精确度。PLC在此领域中的应用,不仅促进了工业生产线的自动化,还在数控机床和工业机器人等设备上展示了强大的控制能力。基于此,系统地阐述PLC技术的基本原理与结构,深入探讨其在机电一体化设备中的具体应用,如数控机床和工业机器人的智能控制,分析PLC面临的挑战,预测其未来的发展方向。

PLC技术在电气设备自动化控制中的应用

阐述PLC技术在电气设备自动化控制中的应用特点,包括可编程、灵活性、可靠性、实时性和可视化界面。探讨PLC技术在开关量控制、闭环控制、顺序控制中的控制应用。

基于PLC的豆粕固态发酵温度控制系统设计与试验

为了在豆粕固态发酵过程中给微生物提供适宜的生长繁殖条件,达到良好的发酵效果,对温度变化复杂的发酵环境进行实时的温度监测和控制。采用PLC对发酵罐的温度进行PID闭环控制,设计以37℃为目标值的试验。结果表明,发酵的豆粕中多肽含量、ACE抑制活性在终点时分别达到4.45 g/kg,53.2%,分别比自然发酵状态下提高5.7%和9.92%,温度控制系统有效提高了豆粕发酵产物的质量。研究为面向生产的豆粕固态发酵提供理论基础。