Vol 6, No 1 (2007)

The paper discusses a procedure of space vehicle attitude control recovery combining magnetometric and radionavigation measurements. The efficiency of the procedure is confirmed on a model task.

The first part of the paper presents mathematical formulations of the tasks of optimizing flights of space vehicles with low-thrust engines and methods of their solution. The peculiarities of mathematical motionmodels used for control optimization within the frames of different tasks are discussed.

The paper deals with a system that uses a magnetic method of compensating microaccelerations and does not require changing the design of a space vehicle (SV). The results of modelling the motion relative to the centre of mass for different types of SV are given.

Deliberate division of used blocks’ structure in the process of their free falling is proposed in order to decrease the area of fall of the carrier rocket’s used blocks. Ballistic calculation of the process of placing payloads in the target orbit and the calculation of the used block’s fall with regard to the structure being divided into parts are presented. Dependence of the payload mass on the area of fall of the carrier rocket’s used blocks is established. The effect of deliberate division of the used blocks’ structure into parts is estimated in general.

The paper presents the construction of mathematical models on the basis of a set of standard modules of initial sentences. On the basis of the rules introduced sentences or functions are constructed which represent different sides of airborne equipment complexes.

The paper presents structural functional schemes of electric supplies for automatic space vehicles with digital and analogue-digital extremal regulators of solar battery power. A procedure for defining parameters of step automatic optimization systems is proposed.

The paper discusses the peculiarities of constructing the algorithmic foundation of a relief correlation-extreme navigational.

The paper discusses the use of analytical and numerical models to calculate a complex of working fluid pressure oscillation damper inherent characteristics. Convergence of calculation results using both models in the low-frequency region is shown. In the high-frequency region lack of adequate account of the damper expansion cavity parameters’ distribution in analytical models results in overestimating the damper’s design efficiency, which may fail to provide the system’s prescribed serviceability after a damper of this kind is introduced into it. Advantages and disadvantages of each model are stated, frequency areas for their application are defined.

The paper presents an experimental analysis of the initial ignition site in the recirculation area with a turbulent flow of aluminium-air mixture ignited by an electric spark. It has been found out that the nature of initial ignition site development in a turbulent flow of aluminium-air mixture corresponds to the nature of initial site development for a homogeneous combustible mixture.

The paper describes the principle of operation of an automatic particle counter with digital signal processes using the channel of particle detection.An analytical expression for choosing discretization frequency and the quantization step of an analogue-to-digital converter (ADC) are defined based on the predetermined error of pulse amplitude determination, the pulse being approximated by a part of a sinusoid.

The paper presents an analysis of irregularity of fluid supply by a gear pump using CAD procedures. Refined dependence of instant theoretical capacity of a gear pump on the gear turn angle is proposed. Results of calculating fluid supply irregularity using the proposed method and the recognized ones are given.

The paper analyses the process of axially symmetric drawing of thin material in a die with an elastic holder bearing against the whole flange surface. The proposed drawing method makes it possible to increase the limit coefficient of material drawing.

The paper presents a mathematical model of code mating of an optoelectronic position-to-digital converter. The model takes into account the effect of external destabilizing factors. The main defects of the optomechanical unit are listed and the influence of such factors on the converter response function is shown. An example of visualizing the information about the influence of vibropercussions on response function error for various amplitudes of vibration oscillations is given. The error is calculated and estimated for the case of autocorrection show the adequacy of the model and the efficiency of using autocorrection.

A procedure is proposed for defining stress relief conditional limit using Oding circular specimens. Stress relief conditional limit at room temperature for a prospective alloy 01570 has been defined.

The paper deals with the application of the numerical quadrature method to integrating differential equations of variable-thickness revolution shells for the case of axially symmetric loading. The original system of differential equations is transformed into an integral one. The trapezoid quadrature formula is applied to all the integrals with variable upper limits. This makes it possible to set up a system of linear algebraic equations in order to determine the values of all the functions desired with the prescribed step t.As a result we manage to obtain numerical values of special solutions of the system of differential equations and its general solution containing arbitrary constants.

The paper is devoted to information support of the product life cycle using an aircraft bearing for gas-turbine engines in the «SmarTeam» PDM environment as an example.

The paper analyses the use of evolution and numerical methods for the optimization of complex interrelated screening and control systems under a priori uncertainty using a stochastic tracking system (a tracker, for short) as an example. To compare various approaches a series of experiments have been carried out on specially developed software. When modeling a tracker faults are discovered on the basis of the method of weighted squares of error of closure, adaptation is performed on the basis of the method of auxiliary quality functional. The method of simple stochastic approximation, the method of least squares and the genetic algorithm are used as identification algorithms to as to compare their possibilities. In the comparative aspect the use of evolution and numerical methods for the optimization of complex interrelated screening and control systems is analysed using a stochastic tracking system as an example.