Dimitar Dichev

• Professor
• Vice Dean at Technical University of Gabrovo

This paper presents a new method for correction of dynamic errors occurring when measuring flat surfaces in the presence of mechanical effects. Mechanical effects cause inertial forces and moments that affect the moving components of measuring instruments, thereby causing dynamic errors. The study proposes a mathematical model, on the basis of whic...

An experimental study was performed to investigate the effect of macrogeometric parameters of the mating surface forms on the strength of the cylindrical interference fit joint: taper, bow, barrel, and ovality. Fifteen couplings were made with a nominal diameter of 60 mm and a mating surface length of 70 mm. The bushings had a regular cylindrical f...

The paper proposes an approach to the analysis of production technology based on the proximity of the obtained accuracy to the desired parameters. Such an assessment of technology in terms of quality will allow for a reasonable choice of the best technology and assign technological parameters which can be applied in the conditions of Industry 4.0....

The article presents a new method for increasing the accuracy of linear measurements. The method is developed on the basis of a measurement-computational approach and aims to eliminate the influence of various external impacts existing in a real work environment. The algorithm of this method is created on the basis of an iterative approach, in whic...

A mathematical model for the numerical determination of the quality indicator value allowing one to obtain non-dimensional values in the range from minus infinity to 1 (the maximum usable value) is proposed. Unlike the traditional system of tolerances, in which the suitability can take two values – 0 or 1, the proposed model allows you to obtain in...

This work presents a new model of investigation of dynamic error in devices and systems for measuring moving objects parameters. It substantially enhances analysis accuracy since it is based on the specific features of functioning of this type of measuring systems. The model developed in this work is built around a block diagram in which the inerti...

This work presents a new method of measuring moving objects parameters. Said method allows the development of new generation of measuring systems, which feature better qualitative indicators and metrological characteristics as compared to those that have been in use so far. The basic concept that underlies this method includes a simplified technica...

The paper considers a new method for measuring the angular deviations of moving objects. A specific measuring system is proposed to measure ship roll, pitch, heel and trim. The system consists of two measurement channels operating in parallel. The first channel is built on the position properties of a physical pendulum so as to build the base verti...

The present paper views the results related to the solution of a complicated problem in the area of measuring equipment. The proposed mathematical model makes possible the transfer of the measuring unit, the calibration and verification of measuring equipment operating in dynamic mode on the basis of an output measuring instrument calibrated in sta...

This paper presents a survey of the main publications and general design requirements and problems of inductive power transfer systems for dynamic charging of electric vehicles (EVs). The main different roadbed geometries, based on a single transmitter track and segmented transmitter coil array have been discussed. Different case studies considerin...

The paper considers an algorithm for increasing the accuracy of measuring systems operating on moving objects. The algorithm is based on the Kalman filter. It aims to provide a high measurement accuracy for the whole range of change of the measured quantity and the interference effects, as well as to eliminate the influence of a number of interfere...

In this work are examined the characteristics of the error from nonlinearity of the static characteristic of the measuring instruments. The possibilities to correct this error are analyzed. Mathematical models are presented, in order to allow evaluation of the error from nonlinearity regarding the permissible error of the measurement result, as wel...

The paper presents a new method for building measuring instruments and systems for gyro-free determination of the parameters of moving objects. To illustrate the qualities of this method, a system for measuring the roll, pitch, heel and trim of a ship has been developed on its basis. The main concept of the method is based, on one hand, on a simpli...

One of the most complex problems in measuring equipment is related to the provision of the required dynamic accuracy of measuring systems determining the parameters of moving objects. The present paper views an algorithm for improving the dynamic accuracy of such measuring systems. It is based on the Kalman method. The algorithm aims to eliminate t...

The present paper considers a new measurement concept of modeling measuring instruments for gyro free determination of the parameters of moving objects. The proposed approach eliminates the disadvantages of the existing measuring instruments since it is based, on one hand, on a considerably simplified mechanical module, and on the other hand, on th...

The present paper considers a new model for the formation of the dynamic error inertial component. It is very effective in the analysis and synthesis of measuring instruments positioned on moving objects and measuring their movement parameters. The block diagram developed within this paper is used as a basis for defining the mathematical model. The...

The present article views a measuring system for determining the parameters of vessels. The system has high measurement accuracy when operating in both static and dynamic mode. It is designed on a gyro-free principle for plotting a vertical. High accuracy of measurement is achieved by using a simplified design of the mechanical module as well by mi...