Abdulah Aksamovic

Model of a hybrid renewable energy system: Control, supervision and energy distribution

This paper presents a concept design of a hybrid renewable energy system (HRES). The proposed HRES design specifies the operation of the following units: a pumped-storage hydro power plant, a wind power plant and a solar power plant. Since the pumped-storage hydro power plant represents the most complex entity of the HRES, special emphasis is placed on its two control loops: the water tank level control loop and the load-depended frequency control loop. Models of these control loops provide the means for efficient controller design and implementation. In order to achieve effective energy distribution and reliable power supply of the consumers, a switch logic architecture has been developed. Since the HRESs final energy production highly depends on the process of energy conversion, the performances of three types of power converters are analysed. This includes the parametrisation, modelling and simulation of such converters. Finally, a graphical user interface (GUI) for purposes of data monitoring, control and supervision within the designed SCADA system, is presented. The proposed HRES design represents the foundation of the system implementation that aims at serving as a platform for research, education and a broad range of projects on renewable energy.

Parameter identification and digital control of speed of a permanent magnet DC motors

The digital control of speed of a permanent magnet DC motor based on a digital computer is analyzed in this paper. Datasheet information about the DC motor was initially unknown. Therefore, the parameter identification and parameter estimation of the motor was done. A type of PID controller, which parameters were optimized (PI), was used in process of controlling the speed of the motor. DAQ acquisition card was used for the purposes of motors parameter identification and realization of computer control of motor speed in closed feedback loop. Manipulations with the same DAQ card were done using Matlab/Simulink software package. Experimental results were compared with the results obtained by simulation.

Similarities in development of digital computers and mobile robots

This paper presents a history of development of digital computers, PCs, and experimental mobile robots. Criteria for forming performance indexes of experimental mobile platforms are defined. A comparison of feature of development of digital computers and experimental mobile robots are given. Effects of applications of PCs in mobile robotics are stressed, and certain future development of mobile robotics have been discussed.

Plantar Pressure Measurement Transformation Framework

Pedobarography measurements of pressure distribution across the plantar surface can be a source of valuable information for gait analysis in context of injury prevention, improvement in balance control, diagnosing disease, and gait analysis. Different applications demand different measurement types: platforms in the gait labs or in-shoe smart soles, and subsequent analysis methods vary with the application domain. Although the pedobarography is considered experimental, technology advancements in the field of IoT, and popularity of collecting different data linked to human activities and behavior, are contributing to increase in pedobarography research. Comprehensive analysis of research results is impeded since the data collecting is not standardized, and differ in volume and structure, thus not facilitating comparative analyses, as it is a case with other biomedical signals as ECG or EEG. In our research we have implemented software framework in Python language with objective to extract relevant pedobarography information using foot segmentation and data aggregation algorithms. In order to validate our solution we processed data from public plantar pressure data set and transformed it in data sets comprising pressure signals covering selected number of foot segments, down to one sensor signal. The proposed data transformation application can help in data sharing and comparison of different approaches in pedobarography.

Challenges in the design of the MAC protocols for wireless sensor networks using VHDL

In the design of MAC protocols for wireless sensor networks (WSN) it is necessary to fulfill some requirements such as low energy consumption, scalability, simplicity, etc. These requirements are not easy to fulfill from the viewpoint of implementation on FPGA or ASIC technologies. Therefore, in this paper we identify some challenges encountered during the design of MAC protocol for WSN. For some of these challenges, potential solutions are discussed. To illustrate the proposed solutions SMAC protocol is chosen. VHDL design of the S-MAC protocols is experimentally verified on the Altera EP2C5 FPGA development system.