Zoran Jovanovic - Academia.edu (original) (raw)

Papers by Zoran Jovanovic

Engineering, Technology & Applied Science Research, 2012

It is well known that fuzzy logic can be used in the control of complex systems described by high... more It is well known that fuzzy logic can be used in the control of complex systems described by highly nonlinear mathematical models. However, the main difficulty in the design of a fuzzy controller comes with the adjustment of the controller’s parameters that are usually determined by human experts’ knowledge or trial and error methods. In this paper, we describe an implementation of fuzzy logic in order to reduce oscillations during the positioning of a 3D crane system. The fuzzy controller’s structure is quite simple, requiring only two input variables. The proposed fuzzy controller has been applied to an experimental laboratory framework and results show that oscillations are significantly reduced.

Facta Universitatis, Series: Automatic Control and Robotics, 2019

The paper explores the Proportional-derivative controller for a double integrator plus dead time ... more The paper explores the Proportional-derivative controller for a double integrator plus dead time processes, which is a challenging control problem, that is designed based on the existing Proportional-integrative controller for integrator plus dead time processes. The PD controller is extended with an integral action and an ideal PID controller is received. The parameters of both controllers are received by using the pole placement technique, whereby the transcendent characteristics equation of the closed loop system is solved by using the Lambert W function. The paper also examines the influence of the desired poles of the system with a closed feedback as well as the influence of the disturbance and the change of the DIPTD processes parameters onto the received control system performances. The results received by simulation, and the quantitative indicators, show that the proposed control system has better performances in comparison to the control systems obtained by other methods in...

6th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2003. TELSIKS 2003.

In this paper a class of continual nonlinear oscillators has been presented, with respect to init... more In this paper a class of continual nonlinear oscillators has been presented, with respect to initial condition, achieve numerous different amplitudes, i.e. with several steady states. Mentioned oscillators are able to generate oscillations with exactly defined amplitudes and frequency. Oscillator generates periodical oscillation and it is invariant to external disturbances.

Advances in Electrical and Computer Engineering, 2013

ABSTRACT The control of anti-lock braking system is a great challenge, because of the nonlinear a... more ABSTRACT The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.

2009 9th International Conference on Telecommunication in Modern Satellite, Cable, and Broadcasting Services, 2009

A new class of the almost orthogonal filters is defined in this paper. These filters are a genera... more A new class of the almost orthogonal filters is defined in this paper. These filters are a generalization of the classical orthogonal filters commonly used in the circuit theory, control system theory, signal processing, and process identification. Almost orthogonal filters generate the series of almost orthogonal Legendre functions on the interval (0, ¿). It's a well known fact that every

Radiation Protection Dosimetry, 2014

Monte Carlo simulations were performed to evaluate dose for possible treatment of cancers by boro... more Monte Carlo simulations were performed to evaluate dose for possible treatment of cancers by boron neutron capture therapy (BNCT). The computational model of male Oak Ridge National Laboratory (ORNL) phantom was used to simulate tumours in the lung. Calculations have been performed by means of the MCNP5/X code. In this simulation, two opposite neutron beams were considered, in order to obtain uniform neutron flux distribution inside the lung. The obtained results indicate that the lung cancer could be treated by BNCT under the assumptions of calculations.

Electronics and Electrical Engineering, 2012

This paper presents a new method for modelling dynamic systems based on quasi-orthogonal function... more This paper presents a new method for modelling dynamic systems based on quasi-orthogonal functions. First, we defined a new class of Legendre type quasi-orthogonal functions that can be used for signal approximation as well as for modelling, analysis, synthesis, and simulation of dynamic systems, especially systems that suffer from some imperfections. In this paper, functions have been applied in modelling of cascade-connected dynamic system, typical for tire industry. Considered rubber cooling system is a represent of complex, nonlinear, and stochastic systems with imperfections. Developed quasi-orthogonal adjustable models can be used for modelling of arbitrary dynamic systems. Optimal model parameters in the sense of the mean-squared error were obtained using genetic algorithm. For experimental purposes, simplified cascade-connected system with four transporters has been practically realized. The experimental results proved the accuracy, simplicity, and quality of realized quasi-orthogonal model.

International Journal of Science and Advanced Technology IJSAT, 2012

Tehnika-Elektrotehnika, 2010

Two new type the orthogonal filters, based on almost orthogonal and quasi-orthogonal functions, i... more Two new type the orthogonal filters, based on almost orthogonal and quasi-orthogonal functions, is proposed in this paper. Recent results in these fields used for formed and designed of almost orthogonal and quasi-orthogonal filters. First, almost orthogonal filters Legendre type were designed on the basis of almost orthogonal functions. Then, derived a new class quasi-orthogonal functions, which used for designed a new class quasi-orthogonal filters Legendre type. The filters described are very suitable for analysis, ...

Acta Polytechnica Hungarica, 2021

This paper discusses the estimation of the processes, that can be described by the first-order pl... more This paper discusses the estimation of the processes, that can be described by the first-order plus dead time, system model. Two methods of parameter estimation are proposed in this paper: the closed-loop under the proportional controller step test and the relay feedback test. The standard symmetrical relay and the preload relay, were used with the Relay feedback. Based on the data, from the recorded response, the parameters of the FOPDT model were estimated, by means of manual calculation using the Lambert W function. The produced results were compared to the results using other methods, in the current literature. Illustrated results were shown through a simulation of several different processes, as well as, with the example of the linearized model, of the pupillary light reflex system.

Elektronika ir Elektrotechnika, 2018

2018 IEEE 12th International Symposium on Applied Computational Intelligence and Informatics (SACI), 2018

The paper discusses the control of an unstable first order time delay process by using the PID co... more The paper discusses the control of an unstable first order time delay process by using the PID controller. A simple method of receiving proportional, integral, and differential gain of the parallel PID controller based on gain margin is presented in this paper. The results of the suggested method of projecting PID for the desired faster or slower close-loop system response are shown through simulation. The performances of the received close-loop system have been, via simulation, compared with the performances of the other received methods of projecting the PID controller both for the set-point response and for the disturbance response. The received values for IAE and ISE, settling and rise time, indicate that the suggested methods provide better results.

6th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2003. TELSIKS 2003.

A method of measurement and data acquisition for motor vehicle breaking system test device is sho... more A method of measurement and data acquisition for motor vehicle breaking system test device is shown in this paper. With respect to automation of measurement process and reports generating the test device is designed. The device is based on industrial PC and embedded microcontrollers, and developed according to object-oriented design and programming principles.

Strojniski Vestnik-journal of Mechanical Engineering, 2010

A new controller for the optimal speed control of a DC drive is presented in this paper. The cont... more A new controller for the optimal speed control of a DC drive is presented in this paper. The controller employs a variant of fuzzy sliding mode, optimized by a genetic algorithm. Proposed controller has many advantages, such as satisfactory control performance under a wide range of operating conditions, a faster response than conventional controllers and suppressed chattering phenomenon. The simulations, experimental results, and comparative analysis verify the efficiency, excellent performance, and robustness of such a control in the case of a DC servomotor.

Facta universitatis - series: Electronics and Energetics, 2019

The paper proposes a new method of identifying the linear model of a DC motor. The parameter esti... more The paper proposes a new method of identifying the linear model of a DC motor. The parameter estimation is based on the closed-loop step response of the DC motor under a proportional controller. For the application of the method, a deliberate delay of the measured speed was introduced. The paper considers the speed regulation of the direct current motor with negligible inductance by applying 1-DOF and 2-DOF, proportional integral retarded controllers. The proportional and integral gain of the PI retarded controllers was received by using a pole placement method on the identified model. The Lambert W function was applied for the identification and in designing the controller with the purpose of finding the rightmost poles of the closed-loop as well as the boundary conditions for selecting the gain of the PI controller. The robustness of the calculated controllers was considered under the effect of an disturbance, uncertainty in each of the DC motor parameters as well as perturbations...

Significant savings can be achieved by using multiplexer in terms of PLC configuration (lower num... more Significant savings can be achieved by using multiplexer in terms of PLC configuration (lower number of analog modules) and cables for signals transmission. Regarding the distance of measuring elements from control system (this distance can be over 100m, in some cases), multiplexer with four selection inputs transmits 16 measurement signals by one cable and uses only one input of analog module. Without the multiplexer, we need 16 analog inputs and the same number of cables. If we know that the price of one analog input at well known world producers ('Siemens', 'Allen Bradley', 'Schneider electric') is in the range 100-150€ and that we need separated special cable for every measuring canal, benefits of introducing the multiplexer in control system are obvious. Described multiplexer based architecture can be applied to every PLC configuration, no matter which is the producer. In the case of the power station conditions, with constant strong noise and disturbances system is very stable and measuring precision is always in the given boundaries (the most distant Pt 100 element is in the distance of 80m from the concentration point).

Engineering, Technology & Applied Science Research, 2012

It is well known that fuzzy logic can be used in the control of complex systems described by high... more It is well known that fuzzy logic can be used in the control of complex systems described by highly nonlinear mathematical models. However, the main difficulty in the design of a fuzzy controller comes with the adjustment of the controller’s parameters that are usually determined by human experts’ knowledge or trial and error methods. In this paper, we describe an implementation of fuzzy logic in order to reduce oscillations during the positioning of a 3D crane system. The fuzzy controller’s structure is quite simple, requiring only two input variables. The proposed fuzzy controller has been applied to an experimental laboratory framework and results show that oscillations are significantly reduced.

Facta Universitatis, Series: Automatic Control and Robotics, 2019

The paper explores the Proportional-derivative controller for a double integrator plus dead time ... more The paper explores the Proportional-derivative controller for a double integrator plus dead time processes, which is a challenging control problem, that is designed based on the existing Proportional-integrative controller for integrator plus dead time processes. The PD controller is extended with an integral action and an ideal PID controller is received. The parameters of both controllers are received by using the pole placement technique, whereby the transcendent characteristics equation of the closed loop system is solved by using the Lambert W function. The paper also examines the influence of the desired poles of the system with a closed feedback as well as the influence of the disturbance and the change of the DIPTD processes parameters onto the received control system performances. The results received by simulation, and the quantitative indicators, show that the proposed control system has better performances in comparison to the control systems obtained by other methods in...

6th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2003. TELSIKS 2003.

In this paper a class of continual nonlinear oscillators has been presented, with respect to init... more In this paper a class of continual nonlinear oscillators has been presented, with respect to initial condition, achieve numerous different amplitudes, i.e. with several steady states. Mentioned oscillators are able to generate oscillations with exactly defined amplitudes and frequency. Oscillator generates periodical oscillation and it is invariant to external disturbances.

Advances in Electrical and Computer Engineering, 2013

ABSTRACT The control of anti-lock braking system is a great challenge, because of the nonlinear a... more ABSTRACT The control of anti-lock braking system is a great challenge, because of the nonlinear and complex characteristics of braking dynamics, unknown parameters of vehicle environment and system parameter variations. Using some of robust control methods, such as sliding mode control, can be a right solution for these problems. In this paper, we introduce a novel approach to design of ABS controllers, which is based on digital sliding mode control with only input/output measurements. The relay term of the proposed digital sliding mode control is filtered through digital integrator, reducing the chattering phenomenon in that way, and the additional signal of estimated modelling error is introduced into control algorithm to enhance the system steady-state accuracy. The given solution was verified in real experimental framework and the obtained results were compared with the results of implementation of two other digital sliding mode control algorithms. It is shown that it gives better system response, higher steady-state accuracy and smaller chattering.

2009 9th International Conference on Telecommunication in Modern Satellite, Cable, and Broadcasting Services, 2009

A new class of the almost orthogonal filters is defined in this paper. These filters are a genera... more A new class of the almost orthogonal filters is defined in this paper. These filters are a generalization of the classical orthogonal filters commonly used in the circuit theory, control system theory, signal processing, and process identification. Almost orthogonal filters generate the series of almost orthogonal Legendre functions on the interval (0, ¿). It's a well known fact that every

Radiation Protection Dosimetry, 2014

Monte Carlo simulations were performed to evaluate dose for possible treatment of cancers by boro... more Monte Carlo simulations were performed to evaluate dose for possible treatment of cancers by boron neutron capture therapy (BNCT). The computational model of male Oak Ridge National Laboratory (ORNL) phantom was used to simulate tumours in the lung. Calculations have been performed by means of the MCNP5/X code. In this simulation, two opposite neutron beams were considered, in order to obtain uniform neutron flux distribution inside the lung. The obtained results indicate that the lung cancer could be treated by BNCT under the assumptions of calculations.

Electronics and Electrical Engineering, 2012

This paper presents a new method for modelling dynamic systems based on quasi-orthogonal function... more This paper presents a new method for modelling dynamic systems based on quasi-orthogonal functions. First, we defined a new class of Legendre type quasi-orthogonal functions that can be used for signal approximation as well as for modelling, analysis, synthesis, and simulation of dynamic systems, especially systems that suffer from some imperfections. In this paper, functions have been applied in modelling of cascade-connected dynamic system, typical for tire industry. Considered rubber cooling system is a represent of complex, nonlinear, and stochastic systems with imperfections. Developed quasi-orthogonal adjustable models can be used for modelling of arbitrary dynamic systems. Optimal model parameters in the sense of the mean-squared error were obtained using genetic algorithm. For experimental purposes, simplified cascade-connected system with four transporters has been practically realized. The experimental results proved the accuracy, simplicity, and quality of realized quasi-orthogonal model.

International Journal of Science and Advanced Technology IJSAT, 2012

Tehnika-Elektrotehnika, 2010

Two new type the orthogonal filters, based on almost orthogonal and quasi-orthogonal functions, i... more Two new type the orthogonal filters, based on almost orthogonal and quasi-orthogonal functions, is proposed in this paper. Recent results in these fields used for formed and designed of almost orthogonal and quasi-orthogonal filters. First, almost orthogonal filters Legendre type were designed on the basis of almost orthogonal functions. Then, derived a new class quasi-orthogonal functions, which used for designed a new class quasi-orthogonal filters Legendre type. The filters described are very suitable for analysis, ...

Acta Polytechnica Hungarica, 2021

This paper discusses the estimation of the processes, that can be described by the first-order pl... more This paper discusses the estimation of the processes, that can be described by the first-order plus dead time, system model. Two methods of parameter estimation are proposed in this paper: the closed-loop under the proportional controller step test and the relay feedback test. The standard symmetrical relay and the preload relay, were used with the Relay feedback. Based on the data, from the recorded response, the parameters of the FOPDT model were estimated, by means of manual calculation using the Lambert W function. The produced results were compared to the results using other methods, in the current literature. Illustrated results were shown through a simulation of several different processes, as well as, with the example of the linearized model, of the pupillary light reflex system.

Elektronika ir Elektrotechnika, 2018

2018 IEEE 12th International Symposium on Applied Computational Intelligence and Informatics (SACI), 2018

The paper discusses the control of an unstable first order time delay process by using the PID co... more The paper discusses the control of an unstable first order time delay process by using the PID controller. A simple method of receiving proportional, integral, and differential gain of the parallel PID controller based on gain margin is presented in this paper. The results of the suggested method of projecting PID for the desired faster or slower close-loop system response are shown through simulation. The performances of the received close-loop system have been, via simulation, compared with the performances of the other received methods of projecting the PID controller both for the set-point response and for the disturbance response. The received values for IAE and ISE, settling and rise time, indicate that the suggested methods provide better results.

6th International Conference on Telecommunications in Modern Satellite, Cable and Broadcasting Service, 2003. TELSIKS 2003.

A method of measurement and data acquisition for motor vehicle breaking system test device is sho... more A method of measurement and data acquisition for motor vehicle breaking system test device is shown in this paper. With respect to automation of measurement process and reports generating the test device is designed. The device is based on industrial PC and embedded microcontrollers, and developed according to object-oriented design and programming principles.

Strojniski Vestnik-journal of Mechanical Engineering, 2010

A new controller for the optimal speed control of a DC drive is presented in this paper. The cont... more A new controller for the optimal speed control of a DC drive is presented in this paper. The controller employs a variant of fuzzy sliding mode, optimized by a genetic algorithm. Proposed controller has many advantages, such as satisfactory control performance under a wide range of operating conditions, a faster response than conventional controllers and suppressed chattering phenomenon. The simulations, experimental results, and comparative analysis verify the efficiency, excellent performance, and robustness of such a control in the case of a DC servomotor.

Facta universitatis - series: Electronics and Energetics, 2019

The paper proposes a new method of identifying the linear model of a DC motor. The parameter esti... more The paper proposes a new method of identifying the linear model of a DC motor. The parameter estimation is based on the closed-loop step response of the DC motor under a proportional controller. For the application of the method, a deliberate delay of the measured speed was introduced. The paper considers the speed regulation of the direct current motor with negligible inductance by applying 1-DOF and 2-DOF, proportional integral retarded controllers. The proportional and integral gain of the PI retarded controllers was received by using a pole placement method on the identified model. The Lambert W function was applied for the identification and in designing the controller with the purpose of finding the rightmost poles of the closed-loop as well as the boundary conditions for selecting the gain of the PI controller. The robustness of the calculated controllers was considered under the effect of an disturbance, uncertainty in each of the DC motor parameters as well as perturbations...

Significant savings can be achieved by using multiplexer in terms of PLC configuration (lower num... more Significant savings can be achieved by using multiplexer in terms of PLC configuration (lower number of analog modules) and cables for signals transmission. Regarding the distance of measuring elements from control system (this distance can be over 100m, in some cases), multiplexer with four selection inputs transmits 16 measurement signals by one cable and uses only one input of analog module. Without the multiplexer, we need 16 analog inputs and the same number of cables. If we know that the price of one analog input at well known world producers ('Siemens', 'Allen Bradley', 'Schneider electric') is in the range 100-150€ and that we need separated special cable for every measuring canal, benefits of introducing the multiplexer in control system are obvious. Described multiplexer based architecture can be applied to every PLC configuration, no matter which is the producer. In the case of the power station conditions, with constant strong noise and disturbances system is very stable and measuring precision is always in the given boundaries (the most distant Pt 100 element is in the distance of 80m from the concentration point).