Plamen Tzvetkov

Vertical Hall Effect Devices in the Basis of Smart Silicon Sensors

Future integrated systems will benefit significantly from the progress in batch manufactured silicon sensors and signal processing techniques. Silicon technologies make possible to produce sensing microdevices combining extreme sensitivity, accuracy and compact devices. Smart sensors on the base of vertical vector Hall effect devices offer a number of benefits including reducing mass, volume and power consumption; greater redundancy of system functions and simpler architecture. In view of these remarkable characteristics, it can be expected that such smart sensors will be used extensively wide if an adequate solution is found to reduce the design cost and simplify the electrical interface. Consequently, cost effective microsystems including vector magnetic sensors, circuits and eventually actuators can be fabricated, opening new perspective markets. This paper presents a new approach in the field of signal processing for magnetic field sensors based on vertical Hall micro structures. A design example is illustrated specific problems and solutions associated with data converters and signal-processing functions for smart sensors.

Motion Detection Using 3D Image Histograms Sequences Analysis

This paper presents an unconventional approach for motion detection using 3D image histogram sequence analysis. The idea of this approach is to remove the process of motion estimation into the field of 3D image histogram sequences by analysis of their statistical characteristics. A functional and statistical model of a system for motion detection has been created. This model includes procedures for image processing like: mode filtering for homogenizing the area of objects and its background, defining 3D image histogram sequences as well as procedures for defining statistical characteristics of the 3D image histograms sequences, choice and analysis of criterions for motion estimation. The experimental results prove that the relationship between statistical characteristics of the 3D image histograms sequences and process of motion estimation is a guarantee for creating a reliable and high precision motion detection system as well as for image compression using 3D entropy functions analysis. Such a system can be used for security control of banks, airports, military objects, embassies, shops etc.

Computerized investigation of robust measurement systems

This paper deals with the development of software for investigating the robust properties of measurement systems and for their design and tuning in order to improve their robustness. The software constitutes Simulink models and m-files as extensions of the libraries of MATLAB. The investigations on continuous measurement systems (a self-balancing system) and discrete systems (ADCs) with improved robustness by using the internal model controller technique revealed new properties-fast dynamics, high accuracy, and discretization error reduction via multiple measurements.

Development of measurement systems with robustness feedback

The aim of this paper is to the design and study of a robustness feedback for an intelligent measurement system and more specifically for the main constituent of its digital part-the analog-to-digit converter. The robustness feedback is based on a simplified reference model of the converter. It is introduced by simple means in order to reduce the quantization error. The main contributions are: design of a new type of structure of analog-to-digit converter; development of a model of the robust converter; quantization error reduction by multiple measurements. The behavior of the proposed converter is studied in environment SIMULINK of the MATLAB program package.

Computerised investigation of robust measurement systems

The paper deals with the development of software for investigating the robust properties of measurement systems and for design and tuning in order to improve their robustness. The software consists of Simulink models and m-files as extensions of the libraries of MATLAB. Investigations of continuous measurement systems (a self-balancing system) and discrete systems (ADCs) with improved robustness using the internal model controller technique revealed new properties-fast dynamics, high accuracy, and discretisation error reduction via multiple measurements.

Remote monitoring of the electrical power quality

This paper considers electrical power as a product which should cover certain quality norms. The voltage characteristics limits according to the standard EN 50160 are accepted as quality norms. The article discusses the approaches to the monitoring and inspection of the electrical power quality. On that aim, two configurations for remote control of the power quality analysers by a computer were tested. The practical realisation could be applied in any case when Internet access or Mobile Network coverage are available.

Intelligent approaches for control of nonlinear plants with significant time delay

The nonlinear plants with significant time delays are difficult to be controlled by classical means. In the present paper intelligent approaches are applied for the design of a nonlinear Smith predictor for compensation of the plant time delay based on a Takagi-Sugeno-Kang plant model and a fuzzy logic parallel distributed compensation (PDC). The design and the advantages of the PDC-Smith are illustrated in temperature control. The good compensation of both the plant time delay and nonlinearity results in faster system step responses in regard to a linear PI, a Smith and a PDC control systems.