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Ivan Bogdanov

Politehnica University of Timisoara, Dean's ofice, Department Member

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Address: Romania

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University Dunarea de Jos of Galati

Marius Constantin Popescu

POLITECHNIKA wroclawska

Alin Brindusescu

Politehnica University of Timisoara

Adriana Filipescu

Rofizah Mohammad

University of Surrey

Claudio Guarnaccia

University of Salerno

Universidad Central del Ecuador (UCE)

Eleftheria Zoaki

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Papers by Ivan Bogdanov

Emergent behaviour evolution in collective autonomous mobile robots

This paper deals with genetic algorithm based methods for finding optimal structure for a neural ... more This paper deals with genetic algorithm based methods for finding optimal structure for a neural network (weights and biases) and for a fuzzy controller (rule set) to control a group of mobile autonomous robots. We have implemented a predator and prey pursuing environment as a test bed for our evolving agents. Using theirs sensorial information and an evolutionary based behaviour decision controller the robots are acting in order to minimize the distance between them and the targets locations. The proposed approach is capable of dealing with changing environments and its effectiveness and efficiency is demonstrated by simulation studies. The goal of the robots, namely catching the targets, could be fulfilled only trough an emergent social behaviour observed in our experimental results.

Efficient Algorithm for Extracting Essential Head Related Impulse Response Data for Acoustic Virtual Reality Development

The new Acoustic Virtual Reality (AVR) concept is often used as a man-machine interface in electr... more The new Acoustic Virtual Reality (AVR) concept is often used as a man-machine interface in electronic travel aid (ETA), that help blind and visually impaired individuals to navigate in real outdoor environments. According to this concept, the presence of obstacles in the surrounding environment and the path to the desired target will be signalized to the blind subject by burst of sounds, whose virtual source position suggests the position of the real obstacles and the direction of movement, respectively. The practical implementation of the AVR concept requires the so-called Head Related Transfer Functions (HRTFs) to be known in every point of the 3D space and for each involved individual. In the present paper, we describe an efficient algorithm for extracting essential Head Related Impulse Response (HRIR) data, we apply it for one person's HRIRs from the Listen Ircam HRTF database. To verify its applicability, after describing the experimental setup, listening tests are also con...

Hardware implementation of field-weakening BLDC motor control

This paper presents a new approach of sensored BLDC (Brushless DC) motor driving in the field wea... more This paper presents a new approach of sensored BLDC (Brushless DC) motor driving in the field weakening (also called phase advanced drive) region, in order to extend the maximum speed of the BLDC motor. The basic concept is the usage of a special position sensor ASIC (Application Specific Integrated Circuit) for which the zero rotor position offset is programmable. Whit this technique the position sensor itself generates phase-advanced rotor position signals to the BLDC motor controller, Therefore the computational power needed to calculate the timing of the phase-advanced commutation points can be significantly reduced, to a simple position angle advance command to the position sensor.

New achievements in assisted movement of visually impaired in outdoor environments

WSEAS Transactions on Circuits and Systems

In the last years, the traditional tools used by visually impaired to navigate in real outdoor en... more In the last years, the traditional tools used by visually impaired to navigate in real outdoor environments (white cane and guiding dogs) are to be substituted with electronic travel aids (ETA). These devices are capable to improve the mobility of blind users in unknown or dynamically changing environment, but up to date no ETAs have been practically implemented. In this paper, the most important theoretical and practical results obtained in the field of ETAs are presented first. Some original results of the author's team, including new concepts in this field, like integrated environment for assisted movement, acoustical virtual reality (AVR), bioinspired solutions are then discussed in more detail. Conclusions and the further developments in this area are also presented.

The Development of CPLD-Based Ultrasonic Flowmeter

The measurement principle of the transit time difference method of the ultrasonic flowmeter is pr... more The measurement principle of the transit time difference method of the ultrasonic flowmeter is presented. The hardware structure and realization method are introduced. The software function and work mode are overviewed. In order to enhancing flowmeter's precision and stability a Xilinx CoolRunner CPLD and a Texas Instruments microcontroller from MSP430 family are applied in high precision timing, complex logical control and communication. The result is a low cost portable solution working with a 3.3V supply and operating with ultrasonic transducers at 1MHz frequency.

Obstacles detection system for visually impaired guidance

In this paper, the 3D obstacles detection system of an integrated environment that improves the m... more In this paper, the 3D obstacles detection system of an integrated environment that improves the mobility of blind persons into a limited area is presented. The proposed solution is bioinspired, i.e. the system detects obstacles in a similar way as a subject with normal sight is looking for obstacles in front of him. For this purpose, both the position of detected obstacles and the position of sensors in 3D environment are available at the output of the system. Based upon this information, an acoustical virtual reality (AVR) is generated, as a substitute for the lost sight of the subject. The content of the paper is focused on 3D obstacles detection, using ultrasonic sensors and the determination of the position of the ultrasonic system, with magnetic sensors and accelerometers. The status of the research and the further developments are also presented.

A low cost CPLD-based ultrasonic flowmeter

Based on the characteristics of ultrasonic non-contact measurement and the combination of tempera... more Based on the characteristics of ultrasonic non-contact measurement and the combination of temperature measurement with ultrasonic flow measurement, a flowmeter was designed. The structure of the ultrasonic flowmeter and the circuits of temperature and flow measurement were described. The design method of the meter with low power consumption was given by selecting MSP430 single chip microcomputer. In order to enhance flowmeter's precision and stability a Xilinx CoolRunner CPLD was applied in high precision timing. The result is a low cost portable solution working with a 3.3V supply and operating with ultrasonic transducers at 1MHz frequency.

Work Directions and New Results in Electronic Travel Aids for Blind and Visually Impaired People

Many efforts have been invested in the last years, based on sensor technology and signal processi... more Many efforts have been invested in the last years, based on sensor technology and signal processing, to develop electronic travel aids (ETA) capable to improve the mobility of blind users in unknown or dynamically changing environment. In spite of these efforts, the already proposed ETAs do not meet the requirements of the blind community and the traditional tools (white cane and guiding dogs) are still the only used by visually impaired. In this paper, research efforts to improve the main two components of an ETA tool: the Obstacles Detection System (ODS) and the Man-machine Interface (MMI) are presented. Now, for the first time, the ODS under development is bioinspired from the visual system of insects, particularly from the locust and from the fly. Some original results of the author's team, related to the new concept of Acoustical Virtual Reality (AVR) used as a MMI is then discussed in more detail. Some conclusions and the further developments in this area are also presented.

Data Acquisition System for Heat Costs Allocation

This work presents an acquisition and management of data system, designated for energy costs allo... more This work presents an acquisition and management of data system, designated for energy costs allocation, developed on three levels: the data acquisition level – where data are recorded with costs allocators installed on the radiators; a data concentration level – were data are read periodical with data concentrators which read data recorded by allocators and a data processing level – for storing data in a PC's data base with a program which allows various works afterwards. The costs allocator and the data concentrator are dedicated systems, implemented around two microcontrollers from MSP430 family and the third component of the system is a PC. The database structure, the PWM encoding solution, the communication protocols, and the user interface for each level, is presented.

Methods for Salient Frescoes Selection Based Mobile Robots Navigation

2006 IEEE International Conference on Control Applications, 2006

In this paper we consider the problem of non-metric/qualitative environment representation for fr... more In this paper we consider the problem of non-metric/qualitative environment representation for frescoes based autonomous robot navigation. Within this framework, the problem of selecting meaningful set of frescoes and some possible solutions are analysed and compared. Experimental results using six different approaches (resemblance, barycentre, Hamming and Levenshtein distances, cross-correlation and selforganizing feature map neural network) are also provided

C# and .NET Framework for uC communication protocol implementation

This paper describes an integrating hardware and software ensemble for the development of microco... more This paper describes an integrating hardware and software ensemble for the development of microcontroller-based computer numerical control system. The discuss is focused on design and implementation of the communication between the PC and a numerical control machine. Among topics covered are: the C#/.NET serial port programming, and further, how to create a Windows application for sending, trough a COM port, the Computer Aided Design/Manufacturing data needed by a numerical control machine. A PIC microcontroller-based communication hardware module was developed and tested.

Hardware Implementation of BLDC Motor Diagnosis

wseas.us

... Vasile Pârvan, nr.2, Timişoara, Timiş ROMANIA [email protected], mihai.basch@etc. up... more

Automated Meter Reading System for Heat Costs Allocation

… on Circuits and …, 2009

The paper presents the design and the implementation of an automated meter reading system for hea... more

MATLAB Model for Spiking Neural Networks

… and Computers in …, 2009

1 Introduction Spiking neural networks are of the last generation. Compared to more traditional m... more

$Figure 8 a). Layer Synchrony at t = 30 ms. 5. Conclusions one is the neural activity object that is supposed to be analyzed. The second one is the time value at which synchrony is evaluated. The third variable is a synchrony threshold that will be explained shortly. The function uses a fraction variable to denote how well two neurons are synchronized with 0 meaning completely out of phase and 1 meaning fully synchronized. Assuming that the neurons are firing at the same rate full de-synchronization occurs when the time distance between spikes is half of the period. The function builds a map of synchrony between each neuron and its neighbors. Then, by comparing the synchrony levels with the synchrony threshold, decides whether the two neurons are sufficiently synchronous to be considered as belonging to the same object. This way segmentation is performed. Lastly, the function maps groups of synchronized neurons to different colors and plots the result. Figure 8a, 8b and 8c illustrates the output of this function at different times along an activity object. The activity object was obtained by simulating a network model similar to the one described above that was sourced with a grey scale image comprising of three objects, each at a different grey level.$

Emergent behaviour evolution in collective autonomous mobile robots

This paper deals with genetic algorithm based methods for finding optimal structure for a neural ... more This paper deals with genetic algorithm based methods for finding optimal structure for a neural network (weights and biases) and for a fuzzy controller (rule set) to control a group of mobile autonomous robots. We have implemented a predator and prey pursuing environment as a test bed for our evolving agents. Using theirs sensorial information and an evolutionary based behaviour decision controller the robots are acting in order to minimize the distance between them and the targets locations. The proposed approach is capable of dealing with changing environments and its effectiveness and efficiency is demonstrated by simulation studies. The goal of the robots, namely catching the targets, could be fulfilled only trough an emergent social behaviour observed in our experimental results.

Efficient Algorithm for Extracting Essential Head Related Impulse Response Data for Acoustic Virtual Reality Development

The new Acoustic Virtual Reality (AVR) concept is often used as a man-machine interface in electr... more The new Acoustic Virtual Reality (AVR) concept is often used as a man-machine interface in electronic travel aid (ETA), that help blind and visually impaired individuals to navigate in real outdoor environments. According to this concept, the presence of obstacles in the surrounding environment and the path to the desired target will be signalized to the blind subject by burst of sounds, whose virtual source position suggests the position of the real obstacles and the direction of movement, respectively. The practical implementation of the AVR concept requires the so-called Head Related Transfer Functions (HRTFs) to be known in every point of the 3D space and for each involved individual. In the present paper, we describe an efficient algorithm for extracting essential Head Related Impulse Response (HRIR) data, we apply it for one person's HRIRs from the Listen Ircam HRTF database. To verify its applicability, after describing the experimental setup, listening tests are also con...

Hardware implementation of field-weakening BLDC motor control

This paper presents a new approach of sensored BLDC (Brushless DC) motor driving in the field wea... more This paper presents a new approach of sensored BLDC (Brushless DC) motor driving in the field weakening (also called phase advanced drive) region, in order to extend the maximum speed of the BLDC motor. The basic concept is the usage of a special position sensor ASIC (Application Specific Integrated Circuit) for which the zero rotor position offset is programmable. Whit this technique the position sensor itself generates phase-advanced rotor position signals to the BLDC motor controller, Therefore the computational power needed to calculate the timing of the phase-advanced commutation points can be significantly reduced, to a simple position angle advance command to the position sensor.

New achievements in assisted movement of visually impaired in outdoor environments

WSEAS Transactions on Circuits and Systems

In the last years, the traditional tools used by visually impaired to navigate in real outdoor en... more In the last years, the traditional tools used by visually impaired to navigate in real outdoor environments (white cane and guiding dogs) are to be substituted with electronic travel aids (ETA). These devices are capable to improve the mobility of blind users in unknown or dynamically changing environment, but up to date no ETAs have been practically implemented. In this paper, the most important theoretical and practical results obtained in the field of ETAs are presented first. Some original results of the author's team, including new concepts in this field, like integrated environment for assisted movement, acoustical virtual reality (AVR), bioinspired solutions are then discussed in more detail. Conclusions and the further developments in this area are also presented.

The Development of CPLD-Based Ultrasonic Flowmeter

The measurement principle of the transit time difference method of the ultrasonic flowmeter is pr... more The measurement principle of the transit time difference method of the ultrasonic flowmeter is presented. The hardware structure and realization method are introduced. The software function and work mode are overviewed. In order to enhancing flowmeter's precision and stability a Xilinx CoolRunner CPLD and a Texas Instruments microcontroller from MSP430 family are applied in high precision timing, complex logical control and communication. The result is a low cost portable solution working with a 3.3V supply and operating with ultrasonic transducers at 1MHz frequency.

Obstacles detection system for visually impaired guidance

In this paper, the 3D obstacles detection system of an integrated environment that improves the m... more In this paper, the 3D obstacles detection system of an integrated environment that improves the mobility of blind persons into a limited area is presented. The proposed solution is bioinspired, i.e. the system detects obstacles in a similar way as a subject with normal sight is looking for obstacles in front of him. For this purpose, both the position of detected obstacles and the position of sensors in 3D environment are available at the output of the system. Based upon this information, an acoustical virtual reality (AVR) is generated, as a substitute for the lost sight of the subject. The content of the paper is focused on 3D obstacles detection, using ultrasonic sensors and the determination of the position of the ultrasonic system, with magnetic sensors and accelerometers. The status of the research and the further developments are also presented.

A low cost CPLD-based ultrasonic flowmeter

Based on the characteristics of ultrasonic non-contact measurement and the combination of tempera... more Based on the characteristics of ultrasonic non-contact measurement and the combination of temperature measurement with ultrasonic flow measurement, a flowmeter was designed. The structure of the ultrasonic flowmeter and the circuits of temperature and flow measurement were described. The design method of the meter with low power consumption was given by selecting MSP430 single chip microcomputer. In order to enhance flowmeter's precision and stability a Xilinx CoolRunner CPLD was applied in high precision timing. The result is a low cost portable solution working with a 3.3V supply and operating with ultrasonic transducers at 1MHz frequency.

Work Directions and New Results in Electronic Travel Aids for Blind and Visually Impaired People

Many efforts have been invested in the last years, based on sensor technology and signal processi... more Many efforts have been invested in the last years, based on sensor technology and signal processing, to develop electronic travel aids (ETA) capable to improve the mobility of blind users in unknown or dynamically changing environment. In spite of these efforts, the already proposed ETAs do not meet the requirements of the blind community and the traditional tools (white cane and guiding dogs) are still the only used by visually impaired. In this paper, research efforts to improve the main two components of an ETA tool: the Obstacles Detection System (ODS) and the Man-machine Interface (MMI) are presented. Now, for the first time, the ODS under development is bioinspired from the visual system of insects, particularly from the locust and from the fly. Some original results of the author's team, related to the new concept of Acoustical Virtual Reality (AVR) used as a MMI is then discussed in more detail. Some conclusions and the further developments in this area are also presented.

Data Acquisition System for Heat Costs Allocation

This work presents an acquisition and management of data system, designated for energy costs allo... more This work presents an acquisition and management of data system, designated for energy costs allocation, developed on three levels: the data acquisition level – where data are recorded with costs allocators installed on the radiators; a data concentration level – were data are read periodical with data concentrators which read data recorded by allocators and a data processing level – for storing data in a PC's data base with a program which allows various works afterwards. The costs allocator and the data concentrator are dedicated systems, implemented around two microcontrollers from MSP430 family and the third component of the system is a PC. The database structure, the PWM encoding solution, the communication protocols, and the user interface for each level, is presented.

Methods for Salient Frescoes Selection Based Mobile Robots Navigation

2006 IEEE International Conference on Control Applications, 2006

In this paper we consider the problem of non-metric/qualitative environment representation for fr... more In this paper we consider the problem of non-metric/qualitative environment representation for frescoes based autonomous robot navigation. Within this framework, the problem of selecting meaningful set of frescoes and some possible solutions are analysed and compared. Experimental results using six different approaches (resemblance, barycentre, Hamming and Levenshtein distances, cross-correlation and selforganizing feature map neural network) are also provided

C# and .NET Framework for uC communication protocol implementation

This paper describes an integrating hardware and software ensemble for the development of microco... more This paper describes an integrating hardware and software ensemble for the development of microcontroller-based computer numerical control system. The discuss is focused on design and implementation of the communication between the PC and a numerical control machine. Among topics covered are: the C#/.NET serial port programming, and further, how to create a Windows application for sending, trough a COM port, the Computer Aided Design/Manufacturing data needed by a numerical control machine. A PIC microcontroller-based communication hardware module was developed and tested.

Hardware Implementation of BLDC Motor Diagnosis

wseas.us

... Vasile Pârvan, nr.2, Timişoara, Timiş ROMANIA [email protected], mihai.basch@etc. up... more

Automated Meter Reading System for Heat Costs Allocation

… on Circuits and …, 2009

The paper presents the design and the implementation of an automated meter reading system for hea... more

MATLAB Model for Spiking Neural Networks

… and Computers in …, 2009

1 Introduction Spiking neural networks are of the last generation. Compared to more traditional m... more

$Figure 8 a). Layer Synchrony at t = 30 ms. 5. Conclusions one is the neural activity object that is supposed to be analyzed. The second one is the time value at which synchrony is evaluated. The third variable is a synchrony threshold that will be explained shortly. The function uses a fraction variable to denote how well two neurons are synchronized with 0 meaning completely out of phase and 1 meaning fully synchronized. Assuming that the neurons are firing at the same rate full de-synchronization occurs when the time distance between spikes is half of the period. The function builds a map of synchrony between each neuron and its neighbors. Then, by comparing the synchrony levels with the synchrony threshold, decides whether the two neurons are sufficiently synchronous to be considered as belonging to the same object. This way segmentation is performed. Lastly, the function maps groups of synchronized neurons to different colors and plots the result. Figure 8a, 8b and 8c illustrates the output of this function at different times along an activity object. The activity object was obtained by simulating a network model similar to the one described above that was sourced with a grey scale image comprising of three objects, each at a different grey level.$