Conference Program

Program of section Industrial

Lectures

 

R. Szabó, G. Szecső:
DIAGNOSTIC SYSTEM FOR DIE CASTING MACHINE BASED ON SIGNAL MODELS
Presenter(s): Szecső, Gusztáv

Abstract

The load of high pressure die casting machine is too high therefore it often leads to break the locking (tie) bars. To avoid breaking tie bars special diagnostic system and process are required.To develop a complete diagnostic system to avoid any breaks of tie bars, because working with non-proper settings or bad-quality tools often leads to the breaking of the overburdened bars. First of all measurements based on the results of research work passed off in the recent years are analyzed and signal models are implemented to solve the mathematical algorithm of an on-line and real time fault diagnosis. Data analyzing and signal model creation consist the following phases: loading existing measurements, data preprocessing (removing NaNs and outliers, data filtering), choosing regression method, curve fitting and implementing signal models. Investigating diagnostic algorithm in one operational cycle of the die casting machine phases are differenced according to the raising, stagnation and falling state of the signals. Finding the best so called DACM – Differencing Along Cycle Method – algorithm a real time implementation of the diagnostic procedure is implemented in LabView environment. Working out the whole diagnostic system current loop data transmission is elaborated in front of the NI USB data acquisition module that can work together with LabView. There are three operational mode in the implemented diagnostic device: Set Sensor Zero, Investigation of Static Cycle and Investigation of Dynamic Cycle. To display diagnostic results a very large and detailed HMI system is constructed to visualize the static and dynamic extensions and tie bar forces, over more the dangerous level of the load differences. Keywords: die casting, tie bar breaking, extensometer, signal model, differencing along cycle, static and dynamic investigation.

 

Domokos Kiss, Gábor Tevesz Dr.:
Obstacle Avoidance of Mobile Robots Based on Dynamic Window Approach
Presenter(s): Kiss, Domokos

Abstract

A mobile robot navigation method is presented which can be used by differentially driven robot platforms designed to operate in lightly cluttered indoor environments. The method uses the dynamic window approach (DWA) for obstacle avoidance. This approach carries out the control commands directly in the two-dimensional space of translational and rotational velocities, taking dynamic constraints of the robot into account. Simulation results show that this method ensures avoiding collisions with static and dynamic objects in the operational space of the robot.

 

Radek Škarda, Martin Goubej:
SELF TUNING ALGORITHM FOR MOTION CONTROL APLICATIONS USING EXTREMUM SEEKING METHOD
Presenter(s): Škarda, Radek

Abstract

This paper deals with automatic tuning algorithm for motion control applications where an electrical actuator is used. In our approach we use a so called extremum seeking algorithm to automatically adjust the controller parameters. The cascade structure of the controller which is commonly used is considered. The tuning algorithm performs a set of experiments with different parameter values and examines the behavior of the closed loop. The goal is to find a parameter set which minimizes the chosen criterion function with respect to setpoint response and disturbance attenuation. The proposed method uses a gradient estimation algorithm which seeks a local extreme of the cost function. No model of the system dynamics is needed due to the gradient-based approach. The paper presents some implementation details of the proposed algorithm and demonstrates the results of experiments with a laboratory motion control model. The results are compared to common design methods and single-shot auto-tuning algorithms.

 

Dejan Ivezic, Milos Tanasijevic:
FUZZY MODEL FOR DEPENDABILITY DETERMINATION
Presenter(s): Ivezic, Dejan

Abstract

Dependability concept was introduced through ISO-IEC standards. Dependability includes availability performance, as its measure, and its influencing factors: reliability performance, maintainability performance, and maintenance support performance. Implementation of dependability concept was developed in detail in IEC-300 standards where dependability objectives were defined and principles of dependability management systems were introduced. Dependability concept constituted a necessary complement to ISO 9000 on quality systems and it was recognized as the most complete concept that describes availability of considered technical system, i.e. presents the most complete quality of service measure. Implementation of dependability concept in essence includes information about system behaviors during up time and down time with regards to design and logistic indicators (concrete information related to reliability, maintainability and maintenance support). Linguistic form can be appointed as the common characteristics of all dependability definitions. Therefore fuzzy sets theory has appeared as natural tool for dependability modeling. The idea of this paper is to introduce model for dependability determination according to IEC 300 standard by fuzzy sets theory utilization. Ability of fuzzy sets to integrate definite, numeric, exact values with linguistic, descriptive values is used for integration of reliability, maintainability and maintenance support performances in indicators of dependability. These indicators are used for analysis of technical systems’ conditions from the aspects of design, construction, maintenance and logistics. These indicators as well as associated dependability expressions itself, are described by linguistic variables which are characterized by a membership function to the defined classes. The proposed model is primarily appropriate for introduction, analysis and synthesis of information related to quality of systems in operation. Such data are often available only as experts’ judgment and estimations. Quality and functionality of proposed model is shown in dependability determination of bucket-wheel excavator systems.

 

Przemyslaw Ignaciuk, Andrzej Bartoszewicz:
SLIDING MODE INVENTORY CONTROL IN SYSTEMS WITH CAPACITATED SUPPLIER AND BATCH ORDERING
Presenter(s): Bartoszewicz, Andrzej

Abstract

In this paper, we develop a new supply policy for periodic-review inventory systems using strict control-theoretic methodology. In the considered systems, the on-hand stock used to satisfy an unknown, time-varying demand placed by retailers (or customers) at a distribution center is replenished with delay from a supply source. The main emphasis of the paper is placed on studying the influence of input constraints (implied by supplier capacity limitation and batch ordering) on the system performance. It is shown that under the proposed nonlinear inventory policy the stock level never exceeds the storage space assigned in the distribution center warehouse. This means that the potential necessity of expensive emergency storage outside the company premises is eliminated. We also demonstrate that the available stock is never entirely depleted, what guarantees a maximum service level.

 

Janusz Pluta, Marek Sibielak:
PRESSURE CONTROL VALVE WITH PIEZOELECTRIC STACK
Presenter(s): Not defined.

Abstract

In this paper prototypical solution of proportional pressure valve, in which proportional electromagnet has been replaced with piezoelectric stack, is presented. The valve in question is a two-stage construction. The first stage of the valve (a pilot) was made basing on the authors' design. An element of series-produced pressure valve was used as the second stage. In order to determine static and dynamic properties of the new valve, laboratory stand research was carried out. LabView tool was used for data acquisition. The results of the research after conversion were processed in Matlab/Simulink tool. In this paper only dynamic properties are presented. In the summary examples of possible usage for the newly constructed valve are suggested.

 

M. Stockmann, R. Haber, U. Schmitz:
IDENTIFICATION OF PLANT-WIDE OSCILLATION SOURCE BY DISTURBING ENERGY TRANSFER DETERMINATION
Presenter(s): Stockmann, Markus

Abstract

A new and reliable method for detection of oscillation source in circuit processes with many control loops is presented. This detection is based on Fourier spectral analysis of all controlled variables. For each control loop power spectrum a performance index is calculated which represents the transmitted power in the disturbing frequency band related to complete power in spectrum. Control loop with highest performance index is assumed to be source of oscillation. Plant-wide disturbing frequencies are detected based on hypothesis testing. By combining disturbing frequency detection and calculating disturbing energy transfer, it is possible to create a plant-wide oscillation map, showing source for every disturbing frequency. Keywords: Oscillation detection, plant-wide control performance monitoring, Fourier spectrum, Industrial application, Hydro-cracker

 

I. Kostial, J. Spisak, J. Mikula:
MODEL BASED SUPERVISORY CONTROL OF MICROFLUID FURNACE
Presenter(s): Kostial, Imrich

Abstract

Optimum operation of granular materials thermal treatment is important for the economic recovery of the valuable minerals, for energy efficiency, as well as from the point of view of pollution control. In many mineral beneficiation operations, the economic objectives translate into the maximization of throughput with suitable constraints on the product quality distribution. While controllers at the regulatory level are capable of controlling the process at the desired values of the process variables, a supervisory control system based on a process model will be required for optimizing the operation. The microfluid furnace model is used in a simulation study to generate a response surface relating the control variables with plant load variables and manipulated variables. This response surface together with a suitably formulated economic objective function is used for on-line optimization to determine the optimum setpoints for the controlled variables in the supervisory control system. The model based supervision together with the regulatory layer control has been tested using simulation. Results demonstrate the utility of the model-based supervisory control technique. Model-based approaches can be used to confront several of the challenging performance issues in the material thermal treatment. For the model-based supervisory control a human-machine interface was developed for on line, interactive communication utilizing a furnace simulation model. The model is used for interpretation, planning, and execution of the task segments through the autonomous controllers. For the purposes of outlining tasks, a human operator controls a simulation model to generate a sequential list of desired sub-goals for a furnace. A graphic user interface displayed operational state and model parameters. Also, because the human operator is specifying controller’s set-points, and allowing the autonomous control capabilities of the furnace to coordinate the actual trajectory between set-points, a provision is made to preview the proposed trajectory for approval or modification before execution. Results demonstrate the utility of the model-based supervisory control technique. Key to the new approach is a model of a furnace which takes into account the physical nonlinear behaviour within each zone at the local level, the inter-zone behaviour at the intermediate level and overall plant performance monitoring at the higher level. Through the use of a priori knowledge in the development of the model the paper stresses the fact that optimum plant performance, hence profitability at the higher level, can only be achieved through a thorough understanding of the issues at the lower and intermediate level. In particular, the paper proposes a new predictive supervisory control strategy which is able to proactively administer set points at the intermediate level to ensure that the exit product quality is achieved.

 

M. Jachimski, G. Wróbel, Z. Mikoś, G. Hayduk, P. Kwasnowski, A. Ożadowicz, M. Noga:
SafetyLON network protocol - safe protocol according to the EN–61508 standard
Presenter(s): Not defined.

Abstract

Local Operating Network (LON) technology developed by Echelon is one of the most common network solutions used in building control automation. Recently an increasing need to establish a technology for safety related and secure data communication within control systems may be noticed. An international standard IEC 61508 has been developed as a result for such necessity. LON node device and communication protocol compliant with safety integrity level 3 (SIL 3) was developed during the European Project “SafetyLON”. The paper describes the basis of safe network protocol which allows safe communication over standard, unsafe LON network. New protocol is backward compatible: it can operate using standard LON network infrastructure and both standard, unsafe and safe messages may be transmitted at the same time. First part of the paper presents the idea of the LonTalk protocol. LonTalk protocol follows all 7 layers of the Open Systems Interconnection (OSI/ISO) model. Several specialized microcontrollers firmware provide support for the protocol, e. g. Neuron Chip and LC3020. LonTalk protocol is very flexible: it can operate on many physical medium (twisted pair, power line), it enables several modes of nodes addressing and packets routing and it implements transmission error detection. But LonTalk protocol does not allow safe communication according to the EN-61508 standard. The next part of the paper describes the SafetyLON frame which is embedded into the standard LonTalk frame. This feature allows to transfer the safe communication frame over standard LON network. The SafetyLON frame consists of two nearly identical subframes. Each subframe consists the same data field but the CRC sums of each data fields are calculated using different polynomials. It causes that the probability of undetected error appearance is less than 10-15. Each SafetyLON message has time stamp added by message producer to detect too big delays in data transfer and errors in message sequences. The message is accepted by the consumer if the difference between time stamp and local consumer time is less than 1 s. Additionally each message received with valid time stamp rearms local watchdog which allows to detect lost messages. The SafetyLON protocol implements also some services. The most important are: time synchronization and cyclic data transfer. Each communication failure: CRC error, watchdog overrun due to lost message cause the consumer to reach safe state. SafetyLON devices and communication uses SafetyLON protocol to create a distribution control system which is compliant with safety integrity level 3 (SIL 3). This feature allows to implement safety related functions directly in control system, for example emergency buttons, fire detection, emergency doors, elevators.

 

G. Wróbel, M. Jachimski, Z. Mikoś, G. Hayduk, P. Kwasnowski:
SENSE - Smart Embedded Network of Sensing Entities.
Presenter(s): Wróbel, Grzegorz

Abstract

Faculty of Electrical Engineering, Automatics, Computer Science and Electronics of AGH - University of Science and Technology is participating among 8 other partners in European Sixth Framework Program in Collective Research Project titled “SENSE – Smart Embedded Network of Sensing Entities”. The SENSE project (Smart Embedded Network of Sensing Entities) will develop methods, tools and a test platform for the smart adaptive wireless networks of embedded sensing components. A test platform for a civil security monitoring system will be developed as a test application, composed of video cameras and microphones. It will be installed in an airport, to yield real data and performance goals from a realistic test environment. Each sensor is a stand-alone system consisting of multiple embedded components: video, audio, and wireless networking. The security application will implement object/scenario recognition. Nodes will recognize local objects, using a combination of video and audio information, and neighbouring nodes will exchange information about objects in a self-organizing network. The result is a global overview of current objects and events observed by the network. First part of the paper presents the idea of SENSE network. The network is an ambient intelligent system which adapts to its environment, creates ad-hoc networks of heterogeneous components, and delivers reliable information to its component sensors and the user. The sensors cooperate to build and maintain a coherent global view from local information. Newly added nodes automatically share knowledge with their neighbours. The network is scalable due to local information processing and sharing, and self-organizes based on the physical placement of nodes. Nodes are able to infer high-level knowledge about their environment from low-level sensor inputs. They consist of video system, audio system, central processor, power source and wireless networking. The system will be utilized in a security application that will implement object/scenario recognition in an airport environment. Second part of the paper presents installation and testing of the SENSE system. Final installation in context-rich, realistic environment is done in the passenger area of Kraków International Airport. University of Science and Technology is responsible for relevant application-context testing and evaluation. There are several test scenarios which will be run at the airport such as: unattended luggage, tracking person who dropped luggage, unusual human behaviour, not pre-defined unusual behaviour, running person, crowd generation detection, specific sounds, sound of shooting, sound of scream, etc. These scenarios should be recognized as unusual events and generate alarms to operators. The paper will describe both SENSE system installation itself and testing environment together with testing methodology.

 

Nimród Kutasi, András Kelemen, Szabolcs Mátyási, Mária Imecs:
HARDWARE IMPLEMENTATION OF EXPLICIT MODEL PREDICTIVE CONTROL OF THREE-PHASE PWM RECTIFIERS
Presenter(s): Not defined.

Abstract

The paper presents a DSP based implementation of explicit model predictive control of a three-phase PWM boost rectifier. PWM rectifiers are inherently hybrid systems with several constraints which have to be taken into account. This is the reason why predictive control of these converters is a popular research area

 

Maria IMECS, Cs. SZABO, I. I. INCZE:
COMPARISON OF ROTOR- AND STATOR-FIELD-ORIENTED CONTROL STRUCTURES OF THE INDUCTION MOTORS
Presenter(s): Imecs, Maria

Abstract

In the paper are described and compared the rotor- and stator-field-orientation procedures of the squirrel-cage induction motors. It is presented an analysis of the vector control structures based on the field-orientation principle. There is treated the influence of the inverter PWM method and the motor-parameter dependence of the control structure on the performances of the control system. The simplest vector control structure for induction motor drives is achieved by current controlled static frequency converter (like voltage-source inverters with current feedback PWM), rotor-field orientation and rotor flux control. It is not affected by the motor parameters (excepting field identification and controller tuning). Furthermore, such a control system presents the best performances with respect to schemes with stator-field orientation, stator-flux control and/or the proper voltage control of the induction motor drive. Some motor-control-oriented digital signal processing (DSP) equipments present on the market don’t dispose over implementation possibility of the current-feedback PWM, suitable for current-controlled voltage-source inverters. They are suitable only for the voltage-feedforward PWM, like carrier-wave and space-vector modulation. That means the induction motor may be supplied by a proper voltagesource converter with voltage-control PWM. In rotor-field-oriented schemes the computation of the voltage control variables is sophisticated and affected by the motor parameters like as rotor resistance, rotor time constant, leakage coefficients and others. Consequently, the drive control performance may be lightly damaged. Usually this problem is solved by renouncing on the rotorfield- orientation and rotor-field control and applying stator-field-orientation with statorfield control. Stator-field orientation leads to a much simpler stator-voltage computation and dependent only on the stator resistance. The paper presents simulation results and implementation aspects of different field-oriented vector control structures.

 

N. Ş. PREDA, D. C. RUS, I. I. INCZE, Maria IMECS, Cs. SZABÓ:
FIXED-POINT DSP IMPLEMENTATION OF ADVANCED DISCONTINUOUS PWM METHODS
Presenter(s): Incze, Ioan Iov

Abstract

This paper proposes an optimized method for implementing several discontinuous pulse width modulation (PWM) techniques on a fixed point digital signal processor (DSP). The discontinuous PWM methods treated are 4 methods derived from the classic space vector modulation (SVM) technique for a three phase inverter, and which are named Flat-Top (FT) methods after the shape particularities of the resulting reference waveform. The 4 discontinuous SVM methods (Full FT, Split FT, Shifted Right FT and Shifted Left FT) are modeled using MATLAB®’s Simulink and then implemented using Real-Time Workshop and Code Composer Studio on the eZdsp development board (which uses the TMS320F2812 Texas Instruments DSP). The method proposed has the advantage of identifying the position of the reference space vector without using any trigonometric or complex mathematical function, uses p.u. values for the on-times of each inverter leg in order to improve the fixed-point computation losses and uses the DC voltage reference for easy compensation in case of voltage ripples. The simulation and implementation results show the particularities of the Flat-Top modulation methods (the flat portions), which yield fewer commutations inside the inverter and the ability to choose a Flat-Top method in correlation with the character of the inverter’s load in order to reduce furthermore the commutation losses. Also a performance analysis was made to show the harmonic content of the Flat-Top SVM modulated waveforms and the total harmonic distortion factor. The papers is structured into six sections: introduction, Flat-Top SVM methods, Simulink modeling, eZdsp implementation, results and analysis, and conclusions.

 

Ján Turán, Ľuboš Ovseník, József Vásárhelyi:
Optically Powered Industrial Barometric System Architecture
Presenter(s): Not defined.

Abstract

Industrial barometric systems are used in various control and monitoring systems in mines, chemical plants, petrochemical industry, etc. Key elements and architecture of the developed optically powered industrial barometric system are discussed. Finally some experimental results of system performance are presented.

 

A. EGRI, T. PANA, O. STOICUTA, V. SIRB , N. STOICUTA:
POZITION CONTROL SYSTEM FOR THE INDUSTRIAL ROBOT
Presenter(s): Not defined.

Abstract

The purpose of this paper is to present a new synthesis of the estimator Gopinath extended used in vector control of the position of GMF360 industrial robot. The extended Gopinath observer proposed in this paper is designated to estimate the rotor flux components and the rotor resistance of the induction motor. This work presents a new strategy to assign the Gopinath matrix elements of the flux estimator in the EGO observer. The studied control system is based on the direct rotor flux orientation method (DFOC). In the second part of the paper we present the vector position control system of the GMF360 industrial robot.

 

TUMA, J. & SKUTA, J. & KLECKA, R., & LOS, J. & SIMEK, J.:
Active vibration control of journal bearings with the use of piezoactuators
Presenter(s): Not defined.

Abstract

The paper presents the results of the first test with the active vibration control of journal bearings. The test stand consists of a rigid rotor, which is supported by two journal bearings. The rotor is driven by an inductive motor. The journal bearing pedestal contains a movable bushing. The bushing position is controlled by two piezoactuators. The journal vibration inside the bearing bushing is measured by a pair of proximity probes, which are arranged mutually perpendicularly. A system, based on a PCL, is controlling RPM of the rotor and is enabling run-up, coast-down and steady-state rotation at the controlled way. A real-time simulator dSpace as a controller is determining the voltage for the piezoactuators according to error signals produced by the proximity probes. The mentioned voltage is connected to the input of an amplifier, which is controlling force and displacement of two pairs of piezoactuators. The active vibration control is aimed to eliminate instabilities due an oil film and to extend the operational range of a rotor rotational speed.

 

Ildiko BOLKENY:
ENHANCED HEAT-CONTROL SYSTEM ON PLC
Presenter(s): Not defined.

Abstract

Oil and gas production laboratory tests are performed by setting the real conditions. As the drilling reaches deeper and deeper layers, the pressure can be up to 1000 bar, while the temperature is at 200 ºC. The PVT-MIVI 1000/230 equipment is suitable for setting this high temperature condition. Heating-control of the equipment is realized by PID algorithm. The article is about an analysis of the heating-control. (POSTER presentation)

 

Peter BORSODY:
HIGH PRESSURE MERCURY FREE PVT CELL CONTROLLING
Presenter(s): Not defined.

Abstract

The Oil and Gas technology extraction must be modelled in a laboratory. The modelled environment, its the real physical parameters, pressure, volume and temperature can be measured. That developed modern laboratory measurement system contains two intelligent device, which are connected to a computer and fully controlled by software. The object oriented software was developed in a reusable and flexible structure. (Poster presentation)

Posters

 

Jaromir Zavadil, Lenka Landryova:
VISUALIZATION OF TECHNOLOGICAL PROCESS

Abstract

Visualization of processes is in use today by virtually all larger companies. On the market there are many software environments used to create visualization applications. This work deals with the creation of these applications. It focuses on the software environment InTouch v.10.0 using ArchestrA Integrated Development Environment (IDE). InTouch program enables you to create graphical views of any manufacturing technologies on a computer screen, their control and dynamic animations that display the current conditions of real-time operating systems. InTouch v.10.0 brings the most functional product improvements since it was first placed on the market. The presented application shows new functionalities of the new version and introduces breakthrough architecture and ArchestrA graphics options of new technologies. This new InTouch 10.0 solution works on Wonderware System Platform 3.0 systems. It includes a traditional WindowMaker development environment and ArchestrA Integrated Development Environment (IDE) for the joint development of applications and for the development of solutions based on Wonderware System Platform Platform 3.0. An application I designed monitors an induction motor. Four variables - voltage, current, frequency and speed of the engine are monitored. Engine speed can be directly entered from the visualization application. The monitored system in InTouch application is located on the computer with the software equipment that communicates with the PLC via Ethernet, which is further connected via the Profibus with a frequency converter, which controls the engine. The task of the PLC program is also to transmit the data from the converter to the visualization and vice versa. Interaction of a visualization application with a program located in the PLC is facilitated through the OPC protocol and the OPCLink application.