The aim of this paper is to apply and adapt methods and formalisms from the computer science to the field of automation. It describes a method to enable formal verification of PLC programs written in the LD language (...
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The aim of this paper is to apply and adapt methods and formalisms from the computer science to the field of automation. It describes a method to enable formal verification of PLC programs written in the LD language (IEC 61131-3) . The principle of the method is to define an operational semantics for the language (description of the behavior of its primitives in terms of state automaton), to encode this definition using a symbolic model-checking tool and check if safety and liveness properties are held by the system. These properties are expressed using the LTL and CTL temporal logics.
The paper presents modified idea of program execution in the programmable logic controllers (PLCs). Instead of serial cyclic execution is proposed event sensitive cyclic execution. Proposed approach to program executi...
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The paper presents modified idea of program execution in the programmable logic controllers (PLCs). Instead of serial cyclic execution is proposed event sensitive cyclic execution. Proposed approach to program execution allow for selective execution of program blocks or tasks provided calculation condition for this part has changed since last time. Proposed method can be implemented as software modification or as hardware accelerated solution. The most important part of the idea is task or subprogram triggering condition computation. Different method of program optimization are discussed. Finally hardware implementation of event triggered system is presented.
programmable logic controller (PLC) characteristics for automatic dimensioning and allocation in process control. The automation of an industrial process is invariably faced with the decision of the optimal resources ...
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programmable logic controller (PLC) characteristics for automatic dimensioning and allocation in process control. The automation of an industrial process is invariably faced with the decision of the optimal resources for implementation. It is important to find a way of selecting the most efficient programmable logic controller that is suitable to facilitate a particular control process. Variables such as the number of inputs or outputs, program memory size, data memory size, auxiliary memory, timers and counters have to be given the requisite consideration. The method undertaken considers the use of ladder diagrams and XML in the process of modelling PLC characteristics which are organised in form of a database. Criteria for PLC selection are used to provide a list of PLCs or embedded controllers that best fits the control process envisioned.
In order to design a vertical lifting three-dimensional garage control system, and to achieve the mechanical three-dimensional garage of the university automatic operation, the photoelectric sensors, hall pressure sen...
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In order to design a vertical lifting three-dimensional garage control system, and to achieve the mechanical three-dimensional garage of the university automatic operation, the photoelectric sensors, hall pressure sensors and programmable logic controller (PLC) are used. The results show that the three-dimensional garage control system can run safely and reliably, and each sensor can perform fault self-diagnosis and carry out certain treatment on the fault. In conclusion, the three-dimensional garage control system designed is feasible, and it can get wide extension and application.
This study researched from the introduction of PLC, combined with the characteristic of PLC, it discusses the design of full-automatic computer food controlling system based on PLC. programmable logic controller (PLC)...
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This study researched from the introduction of PLC, combined with the characteristic of PLC, it discusses the design of full-automatic computer food controlling system based on PLC. programmable logic controller (PLC) is automation equipment with microprocessor as the key and an electronic system working with figure in working environment. It can be easily interfaced and the programming language is easy to be accepted by engineering technicians. Graphic symbol and means of expression of ladder diagram language is rather close to circuit diagram of relay.
The poster describes the equipment based on PLC for measuring of effectiveness of the accumulator matters. Main part of the equipment is control system with programmablecontroller Tecomat TC 600. The controller provi...
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The poster describes the equipment based on PLC for measuring of effectiveness of the accumulator matters. Main part of the equipment is control system with programmablecontroller Tecomat TC 600. The controller provides measurement according to setting parameters and saves acquired data to the memory. The parameters could be set on the computer with SCADA system. This system also processes measured data. The results are time characteristics of charging and discharging of tested matter, values of effectiveness in each cycle.
Abstract The paper deal with a deep analysis and application of object-oriented methodologies for the design process of industrial machine controllers. The process pass thought the phases of (1) conceptual model devel...
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Abstract The paper deal with a deep analysis and application of object-oriented methodologies for the design process of industrial machine controllers. The process pass thought the phases of (1) conceptual model development of the software artifacts, and (2) model code deployment for the automation system target, which is in general a programmable logic controller (PLC) compliant with the international standard IEC 61131-3 for programming languages. The paper describes a design pattern for the software conceptual model deployment, with a particular emphasis on practical requirements enforced by PLC of different brands. In fact, IEC 61131-3 compliance provides a common “look-and-feel” for programming languages, but does not guarantee straightforward code portability between different PLC vendors. The paper has a great focus on applications and provides an example, based on a generic flow-pack machine, to better explain the proposed methodology.
Abstract This paper makes two key contributions. First there is a definition and implementation of a novel auto-tuned predictive controller. The key novelty is that the modelling is based on relatively crude but pragm...
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Abstract This paper makes two key contributions. First there is a definition and implementation of a novel auto-tuned predictive controller. The key novelty is that the modelling is based on relatively crude but pragmatic plant information. Secondly, the paper tackles the issue of availability of predictive control for low level control loops. Hence the paper describes how the controller is embedded in an industrial programmable logic controller (PLC) using the IEC 1131.1 programming standard. Laboratory experiment tests were carried out in two bench-scale laboratory systems to prove the effectiveness of the combined algorithm and hardware solution. For completeness, the results are compared with a commercial PID controller (also embedded in the PLC) using the most up to date auto-tuning rules.
This paper presents a temporal characterization for automation systems. The final goal is to achieve a whole model in which a schedulability analysis could be applied in order to assure that this kind of systems meet ...
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This paper presents a temporal characterization for automation systems. The final goal is to achieve a whole model in which a schedulability analysis could be applied in order to assure that this kind of systems meet timing non-functional requirements of the application. This work is performed in the context of a Model Driven Development approach. The definition of three Domain Specific Models: control specification, and hardware and software architectures, is the base for the whole model. In particular, the software domain model uses the XML interface defined by PLCopen for expressing IEC 61131-3 automation projects. The information contained in the model of the application is processed to generate the temporal model of the automation system. A specific transformation of this model makes possible to carry out a schedulability analysis of the system. In particular, this is achieved by generating the specific input model of the well-known Modelling and Analysis Suite for Real-Time Applications, MAST.
Using the traditional method to control the transmission process of the tension tower hydraulic tightening device, there is a problem of slow speed step response in the range of device operating speed from 12km/h to 3...
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Using the traditional method to control the transmission process of the tension tower hydraulic tightening device, there is a problem of slow speed step response in the range of device operating speed from 12km/h to 32km/h. For this reason, this paper designs a programmable logic controller-based transmission control method for the hydraulic tightening device of the tension tower. The two-phase static coordinate system is introduced to obtain the voltage equation, flux equation, electromagnetic torque equation and electromechanical motion equation of the hydraulic drive system, and then the mathematical model of the hydraulic drive system is constructed. The full-order observer is regarded as an adjustable model, the appropriate Lyapunov function is selected, and the function stability of the full-order observer is derived, so as to realize the identification of the speed of the tension tower hydraulic tightening device. Based on this, a transmission control model is constructed based on programmable logic controller to realize the transmission control of the tension tower hydraulic tightening device. Experimental results prove that the speed step response rate of this method is higher than that of the traditional method, and the response performance is improved.
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