Autonomous navigation during the final ascent of a spacecraft into the geostationary orbit. II. Simulation of operation of an integrated autonomous SC navigation and control system

This study continues the series of papers devoted to the approach to solving the problem of autonomous navigation of a spacecraft (SC) in a geostationary orbit at all stages of its lifecycle: final ascent, transfer to the operating longitude, remaining at the operating longitude, removal from the orbit, and burial. In [1], we formulated the concept of autonomous navigation of a spacecraft at the stage of its final ascent to a geostationary orbit. This stage is most complicated from the technical point of view, taking into account the nonlinearity of the applied mathematical models, the influence of uncontrollable factors of various physical nature, and the necessity of the application of promising hardware (electric low-thrust engine, onboard receiver of signals from global navigation satellite systems, intersatellite communication channels, etc.). Taking this into account, the only constructive method for proving the viability and efficiency (taking into account the requirements formulated by the customer who placed the order) of the developed concept of the autonomous navigation at the final ascent stage in the mathematical simulation of this process. The subject of this study is to demonstrate the capabilities of the developed concept of autonomous navigation from the point of view of achieving the required level of reliability and accuracy in solving the navigation problem at the final ascent stage. This demonstration is based on the analysis of the results of imitating the simulation of the process of a spacecraft’s final ascent to a geostationary orbit obtained using the specially developed software complex.     

Trajectory control of a high altitude hypervelocity flying vehicle in the midcourse active phase of the flight

An approach to the control of the motion of the center of mass of a high altitude hypervelocity flying vehicle whose engine thrust and aerodynamics strongly depend on the angle of attack in the midcourse active phase of the flight is proposed. This approach provides a basis for the method of the trajectory control of motion. The motion of this flying vehicle is simulated with regard to the disturbed atmosphere. It is shown that the proposed approach can be used to form launching zones of high altitude hypervelocity flying vehicles.     

Search for the Optimal Control over Current Regimes in Electroplating Processes with Multi Anodes at a Diversified Assortment of Treated Articles

Journal of Computer and Systems Sciences International - Methods of controlling electroplating processes are considered, and the shortcomings in the use of basic engineering and structural...     

Integrated navigation system for a space vehicle on a geostationary or highly elliptic orbit operating in the presence of active jam

An onboard navigation system for a space vehicle on a geostationary or highly elliptic orbit including such measurement sources as optoelectronic Earth, Sun, and star trackers, and a multichannel global navigation satellite system receiver is studied. The purpose of this study is to form a general design of an integrated navigation system including the justification of its architecture and operation algorithms based on conditions under which the desired accuracy can be achieved. Based on the analysis of the GPS and GLONASS navigation satellites visibility conditions, the practicality of using a deeply integrated system architecture is established; this architecture can ensure the desired navigation accuracy even when less than four navigation satellites are visible. To integrate various measurements, a special “scalar” modification of the Kalman filter (the so-called integral Kalman filter) is used. As uncontrollable factors, instrument sensor errors and artificial jam in the operation of the navigation signals receiver are considered. The main tool for the analysis of the navigation system error is simulation, which is performed using dedicated software of object-oriented architecture.     

Selecting a Single Result from an Aggregate of Contradictory Alternatives with Use of Multiset Theory

Journal of Computer and Systems Sciences International - We consider basic approaches to decision-making using computer systems. Ambiguous results in decision-making are obtained through the use of...     

Analysis of conditions for ensuring operation of an intertial satellite navigation system of an unmannded aerial vehicle during interference

The paper analyzes the possibility of an automatic low-altitude flight of an unmanned helicopter in terrain following mode in case of interference in the satellite navigation channel. We show that this can be done by using an onboard integrated system that ensures the accuracy of navigation (standard deviation) of 3 meters in plan, 10 meters in height, and 0.5° in orientation angle. These parameters are achieved by integrating the data received from micromechanical inertial sensors and multichannel GLONASS/GPS receiver with an anti-nonmodulated interference system.     

Decision Making in MultiCriteria Problems at the Image Design Stage of Aviation Rocket Technique

Journal of Computer and Systems Sciences International - A number of fundamental decisions that will determine the technical and economic characteristics of the project in the future are laid when...     

Autonomous navigation during the final ascent of a spacecraft into the geostationary orbit. Autonomous integrated navigation system concept

Journal of Computer and Systems Sciences International - This paper is the first in a series of works devoted to the problems of a spacecraft in the geostationary orbit autonomous operation. The...     

Terminal open-loop control for a hypervelocity unmanned flying vehicle in the atmosphere. Part 1

An algorithm for the terminal open-loop control of a hypervelocity flying vehicle with a high lift-drag (L/D) ratio is proposed; this algorithm ensures the implementation of spatial programmed hitting trajectories steering the vehicle to the given spatial domain with required high accuracy and required conditions of approaching this domain. The algorithm is based on the a priori construction of a rational hitting trajectory and the corresponding control vector; the control vector components are the attack and bank angles. At the beginning of the terminal phase, only constraints on the individual components of the vector of initial conditions are imposed: the ranges of altitudes, velocities, and flight path angle. In addition, the requirement for the minimum admissible resolution of the onboard radar that provides informational support at the terminal phase is taken into account in the trajectory construction. Examples of programmed hitting trajectories are given that confirm the fact that the proposed algorithm for the generation of such trajectories and the corresponding attainability sets is computationally efficient.     

Concept of Controlling the Characteristics of Nanotubes by Processing a Catalyst Precursor for Their Synthesis

Journal of Computer and Systems Sciences International - In order to implement the directed synthesis of carbon nanostructures, it is proposed to control the process of their formation using a...