Industrial Control Unit Research Articles

Integrated simulation and control environment for the development and safe start-up of cable driven parallel robots

ABSTRACT This article presents a new environment designed to facilitate the conceptualization and automation of CDPRs (Cable Driven Parallel Robots). Utilizing a platform for robotic simulation, an industrial controller, and a data gateway to communicate both systems, it is possible to emulate CDPR motion in early design, development, and start-up phases. Thus, this simulation environment allows to test how the robot will behave in advance in order to obtain a safer and more reliable first operation with the real robot. An spatially under-constrained CDPR with four cables was used to validate the capabilities of the proposed integrated environment, comparing its performance against an industry-standard hardware prototype. Both the simulation model and the real prototype performed the same trajectory in order to assess a time delay and position errors between them. Evaluation results revealed that the simulation accurately replicated the performance of its industrial counterpart, with a peak divergence of 0.27% in the position of the robot under various speed scenarios. This occurs even when accounting for latency arising from data exchange connecting the industrial control unit to the simulation. The results have shown that the environment is suitable for trajectory control of new CDPR architectures under different dynamic conditions.

Extended kernel density estimation for anomaly detection in streaming data

Machine Learning algorithms based on kernel density estimation (KDE) are said to be well suited for anomaly detection. However, existing approaches mainly cover point anomaly detection. Many industrial applications also require detecting drifts, contextual and collective anomalies. Due to the demand for small latencies, edge computing gains significance and hybrid models are no adequate solution. The main contribution is the EEM-KDE algorithm, which includes extensions of the KDE for detecting all aforementioned types of anomalies in streaming data in the edge. Finally, the proposed algorithm is evaluated showing the capability to detect different types of anomalies using an industrial control unit.

Ubiquitous Control of a CNC Machine: Proof of Concept for Industrial IoT Applications

In this paper, an integrated system to control and manage a state-of-the-art industrial computer numerical control (CNC) machine (Studer S33) using a commercially available tablet (Samsung Galaxy Tablet S2) is presented as a proof of concept (PoC) for the ubiquitous control of industrial machines. As a PoC, the proposed system provides useful insights to support the further development of full-fledged systems for Industrial Internet of Things (IIoT) applications. The proposed system allows for the quasi-decentralisation of the control architecture of conventional programmable logic controller (PLC)-based industrial control systems (ICSs) through data and information exchange over the transmission control protocol and the internet protocol (TCP/IP) suite using multiple agents. Based on the TCP/IP suite, a network device (Samsung Galaxy Tablet S2) and a process field net (PROFINET) device (Siemens Simatic S7-1200) are interfaced using a single-board computer (Raspberry Pi 4). An override system mainly comprising emergency stop and acknowledge buttons is also configured using the single-board computer. The input signals from the override system are transmitted to the PROFINET device (i.e., the industrial control unit (ICU)) over TCP/IP. A fully functional working prototype is realised as a PoC for an integrated system designated for the wireless and ubiquitous control of the CNC machine. The working prototype as an entity mainly comprises a mobile (handheld) touch-sensitive human-machine interface (HMI), a shielded single-board computer, and an override system, all fitted into a compact case with physical dimensions of 300 mm by 180 mm by 175 mm. To avert potential cyber attacks or threats to a reasonable extent and to guarantee the security of the PoC, a multi-factor authentication (MFA) including an administrative password and an IP address is implemented to control the access to the web-based ubiquitous HMI proffered by the PoC.

Viscoelastic Dampers for Rotors: Modeling and Validation at Component and System Level

The aim of this paper is to propose a methodology for the modelling, testing, and the parameter identification of viscoelastic supports for rotating machines at the component and system level. Although the use of this type of dampers is common in rotordynamic applications, the strict dependence on the working frequency of the material parameters makes their behavior hard to predict and recommends grounding the design on experimental data of the characteristics. A dedicated test rig is adopted to characterize the supports and validate the modelling approach at component level. A parameter identification procedure is carried out from the experimental results to extract the mechanical properties of the supports. To this end, a Genetic Algorithm (GA) is adopted to search the most fitting values of damping and stiffness of the reference model. The choice of GA is motivated by the need of adopting a technique that can be easily implemented on industrial control units, being that the dedicated machine is supposed to be used in production lines for testing procedures. The results are obtained in terms of complex stiffness as a function of the frequency and are then translated in classical stiffness and damping components that are commonly used in rotordynamics. Afterwards, they are introduced in the model of a turbo-molecular pump adopted as a case study to evaluate the correctness of the proposed methodology at system level at stand-still and with the pump in rotation. The proposed approach is effective, showing a good match between the numerical model and the experimental results even with a relatively low order model of the viscoelastic supports and on a complex rotordynamic system.

An Automatic Assembling System for Sealing Rings Based on Machine Vision

In order to grab and place the sealing rings of battery lid quickly and accurately, an automatic assembling system for sealing rings based on machine vision is developed in this paper. The whole system is composed of the light sources, cameras, industrial control units, and a 4-degree-of-freedom industrial robot. Specifically, the sealing rings are recognized and located automatically with the machine vision module. Then industrial robot is controlled for grabbing the sealing rings dynamically under the joint work of multiple control units and visual feedback. Furthermore, the coordinates of the fast-moving battery lid are tracked by the machine vision module. Finally the sealing rings are placed on the sealing ports of battery lid accurately and automatically. Experimental results demonstrate that the proposed system can grab the sealing rings and place them on the sealing port of the fast-moving battery lid successfully. More importantly, the proposed system can improve the efficiency of the battery production line obviously.

Review on Security Issues and Attacks in Wireless Sensor Networks

Wireless sensor network is a collection of sensor nodes with limited processor and limited memory unit embedded in it. Sensor networks are used in wide range of applications such as Environment monitoring, health, industrial control units, military applications and many more. This paper defines the security requirements and various attacks on sensor network. This paper also review proposed security mechanisms for WSN.

A low-cost HIL platform for testing professional refrigerators controllers

In this work, we present a Hardware In the Loop (HIL) platform for testing control strategies designed and implemented in a commercial electronic control unit for industrial refrigerators. The architecture structure consists of four elements: (i) a real-time processor, in which a detailed model of the refrigerator is implemented; (ii) the industrial control unit device under test; (iii) an Input/Output (I/O) hardware interface which allows data communication between the real-time processor (model) and the industrial device (control) and (iv) a power PC in order to display and save experimental results. Introducing the HIL methodology in the refrigerator industry could reduce electronic control unit testing costs and save time in the production stage because it is possible to verify the control strategy performances in realtime for several operating conditions and different refrigerator models avoiding expensive and time-consuming test bench procedures.

A New Microprocessor Protection Scheme Based on Digital Signal Processor

Based on the demand of power department, a protection & monitoring device for the power distribution line is studied. The device using DSP as the core technology is a new industrial control unit, which adopts the of dual CPU of DSP+DSP and consists of chip selection unit, A/D conversion, data storage, watchdog circuit, press key, switch quantity detection, control output, communication, display and clock etc. The software system includes two parts: tracking software and protection software. The device ensures the high reliability and feasibility, at same time incarnates the advantage of microprocessor protection by intelligent designs.

Application of SHERPA to Identify and Prevent Human Errors in Control Units of Petrochemical Industry

Introduction. Studying human errors as a risk factor in the occurrence of accidents is necessary. Thus, the aim of this study was to identify, predict and control human errors in industrial control units. Method. This is a case study carried out using SHERPA in the first unit of Zagros Methanol of Asalooyeh, Iran, and its subunits. To collect the required data, various methods were used: observing, interviewing processing specialists and control unit operators, and studying technical documents and records. Results. In total, 222 human errors were identified in various occupational tasks. This study showed that 48.62% of them were action errors, 31.97% were checking errors, 6.75% were retrieval errors, 11.70% were communication errors and 0.90% were selection errors. Conclusion. It can be inferred that this method is appropriate for different industries, and it is useful for identifying human errors leading to hazardous accidents.

New algorithms generate improved templates for biometric recognition

Face detection and eye gaze estimation are crucial components of applications such as virtual reality, video conferencing, video surveillance, face recognition and face database management.1–4 New applications involving human-machine interfaces are under development where eye gaze could be employed to control machines assisting handicapped individuals, or in technologically complex environments such as hospital operating rooms, airplane cockpits, or industrial control units.1, 5–7 Several limitations have been identified in existing face and iris detection methods: some are invasive; some focus on only one eye, do not follow head movements, or only follow very small head movements; some fail to detect eyes while blinking; and some require manual initialization. Additionally, some impose restrictions such as symmetry, which limits the background content. Other methods depend on face skin tone, which varies among different ethnic groups and is dependent upon nearby light sources. These limitations contribute to two particular problems that apply to most methods of face and eye detection: they cannot work in real time, and they are not robust for face rotations.1, 8–12 To allow real-time processing, our first approach was to use anthropometric templates for face and eye detection. This set of templates, which consists of different face sizes, includes key facial features such as eyebrows, nose, mouth, and the lower part of the chin, thus mainly limiting the search to these specific face and eye characteristics. For eye detection, the templates consider an eye region within an elliptical face contour. Our second approach was to design templates using PSO (particle swarm optimization) to search for the best templates,8 or use a local component maximization (CM) procedure.9 The Figure 1. (a) Coarse face detection: original image, coarse directional image, accumulator, superposition of accumulator over original image, and coarse face detection. (b) Fine face detection: original image, coarse face detection, fine directional image, anthropometric face templates, and face detection by face template.

A research group's CACSD environment

The paper describes the recent development of the computer-aided control system design (CACSD) facilities within the Industrial Control Unit (ICU) at the University of Strathclyde. The PC environment now represents the most cost-effective choice in providing the control engineer with access to a powerful range of design facilities. CACSD packages are becoming popular as teaching aids, and show great potential for helping in the dissemination of new theoretical ideas to industry.