programmable logic controllers (PLCs) is proposed for in-process monitoring of fuel alcohol production, both collecting process data and realizing auto-tuning PID and sequence control strategies. In addition, the WinC...
详细信息
ISBN:
(纸本)7560317685
programmable logic controllers (PLCs) is proposed for in-process monitoring of fuel alcohol production, both collecting process data and realizing auto-tuning PID and sequence control strategies. In addition, the WinCC configuration software with a Human-Machine Interface (HMI) is used to monitor the dynamical industrial process. Both the software- and hardware-based applications of our system are also described in details.
programmable logic controllers (PLCs) were a novelty in the automotive industry after their introduction in the early 1970s. Thirty years after their debut, PLCs are the default industrial controller used in a broad r...
详细信息
programmable logic controllers (PLCs) were a novelty in the automotive industry after their introduction in the early 1970s. Thirty years after their debut, PLCs are the default industrial controller used in a broad range of control applications from simple machines to entire production facilities. In the last ten years, PLC development followed the computer industry trend toward networked devices and shared databases. In the last three years, however, vendor products that integrate the PLCs with other networks, smart sensors and smart actuators have increased significantly. Courses and laboratories covering PLC programming and interfacing started to appear in colleges and universities teaching engineering technology programs in the mid 1970s. Today PLC courses and a PLC laboratory are found in almost every engineering technology curriculum. In many institutions, however, the level of PLC technology taught has not progressed beyond simple discrete control using basic ladder logic programming on a stand-alone PLC. Engineering technology laboratories must include exercises using PLC and smart device networks to prepare graduates to work on the robust automation solutions adopted by manufacturing. This paper describes how PLC laboratories need to change to be aligned with current industrial usage.
In this paper, we present the design and practical use of a programmablelogic controller (PLC) training station for use in an undergraduate electrical and computer engineering curriculum. The trainer, based on the Al...
详细信息
The incorporation of programmed-logiccontrollers (PLC) exercises into the chemical engineering's control course at the University of Colorado is discussed. The PLC exercises allows students to learn the fundament...
详细信息
The incorporation of programmed-logiccontrollers (PLC) exercises into the chemical engineering's control course at the University of Colorado is discussed. The PLC exercises allows students to learn the fundamentals of digital logic, logic diagrams and ladder logic programming of PLC's and application to chemical processing. The incorporation into the control course has been made with minimal impact on the rest of the course content. The university already have feedback from recent alumni that their rudimentary knowledge of PLC's has been of value to them in their work.
As more data-path stacks are integrated into system-on-a-chip (SOC), data-path is becoming a critical part of the whole giga-scale integrated circuits (GSI) design. The traditional layout design methodology can not sa...
详细信息
The authors describe a modular control system development for Turbogas Power Units (TPU) based on a PLC (programmablelogic Controller). The starting up control sequence, protections, process supervision, anti surge c...
详细信息
The authors describe a modular control system development for Turbogas Power Units (TPU) based on a PLC (programmablelogic Controller). The starting up control sequence, protections, process supervision, anti surge control and speed/load regulation functions were developed and implanted in a modern high performance PLC according to the state-of-the-art IEC 1131-3 programming standard. Simulation tests were carried out with a dynamic mathematical model of a TPU implanted in an industrial PC (Personal Computer) with hardware interfaces for input/output process signals. The results demonstrated the feasibility of the control system strategy over the whole operating range. With little effort, the control system can be easily implanted in other PLC's (from different manufacturers) thanks to the modular design of the software. The software with modular structure can accept changes of the control strategies.
Today the hardware of logiccontrollers, the PLCs (programmable logic controllers), provide a more or less standard functionality and the control strategies and algorithms are implemented in software. Nevertheless, co...
详细信息
Today the hardware of logiccontrollers, the PLCs (programmable logic controllers), provide a more or less standard functionality and the control strategies and algorithms are implemented in software. Nevertheless, concepts from Software Engineering are rarely applied in this application area. In this contribution it is shown that, besides the fact that the term is rarely used, several methods that are quite common in controller design can be seen as means to improve the software quality as defined in ISO 9126. For the quality characteristics portability and maintainability a new metric is presented. The proposed transparency metric evaluates different aspects of a logic control algorithm to check if this algorithm is easy to understand. The metric is defined for controllers programmed via Signal Inter-preted Petri Nets but can be adapted to other graphical methods like for example SFC. The validity of the metric is experimentally proofed.
Mathematical models and formal methods can be used for verifying / falsifying a discrete event controller just before it is put into operation. If the controller model is verified successfully, one has to translate it...
详细信息
Many systems-on-a-chip (SOCs) include processors as central units to implement diverse algorithms and control peripheral units such as embedded cores. The computing power of the embedded processor can be used to self-...
详细信息
ISBN:
(纸本)1581134622
Many systems-on-a-chip (SOCs) include processors as central units to implement diverse algorithms and control peripheral units such as embedded cores. The computing power of the embedded processor can be used to self-test its own functions as well as to test the other cores within the chip boundary. In BIST methodology, pseudo-random pattern testing can reduce the memory requirements. In addition to general pseudo-random pattern testing, this paper proposes and evaluates a novel selective-random pattern test technique. This technique increases the fault coverage while significantly reducing test application time. This also greatly decreases the memory requirements compared to traditional BIST schemes. The cost for extra hardware is low and the technique is easily integrated with parallel scan and bound- ary scan designs. Copyright 2002 ACM.
This paper discusses a new way of integrating a suite of commercially available, off-the-shelf software tools and hardware to develop a scalable testing platform called Automated Real-Time Test System (ARTS). The main...
详细信息
This paper discusses a new way of integrating a suite of commercially available, off-the-shelf software tools and hardware to develop a scalable testing platform called Automated Real-Time Test System (ARTS). The main function of ARTS is to provide automated functional testing, in order to increase the test coverage of a Personnel Safety System (PSS). Data that resulted from five years of manual testing of the PSS was used as input to several software reliability analysis tools. The results of this analysis allowed us to estimate the reliability of the PSS system's software as a function of test coverage. Two statistical modeling tools selected for the analysis were: 1) SMERFS-statistical modeling and estimation of reliability functions for software, and 2) CASRE-computer aided software reliability estimation. A data table of the Brooks-Motley and S-Shaped Reliability growth models are provided for comparison purposes and were use to help in selecting the best model that fit our data.
暂无评论