Mel’niсk V. N., Karachun V.V., Levсhenkо O.I.

National Technical University of Ukraine «KPI»

WORKING FEATURES OF NAVIGATION DEVICES

Successful Tsyklon launches of LV-s have a record reliability. They are used in a double-stage version Tsyklon-2 and a three-stage version Tsyklon-3 (fig. 1). The first one provides the insertion of devices of up to 4 ton mass to low circular orbits. The other one commits single or group spacecraft insertion of total up to 4 ton mass to low circular and elliptic orbits.

The conversion LV Dnipro (fig. 2) is constructed on the base of intercontinental ballistic missile RS-20 ( SS-18 “Satana” ). Since 2003 construction works of the autonomous cosmic towboat (ACT) for LV Dnipro have been started. The modifications of Dnipro will allow to enlarge the the useful load’s mass on the one hand , to realize launchings of large-tonnage satellites of mass to high eleptic orbits on the other hand, and also to realization of flights to the Moon and primary planets.

On basis of argumentation one can claim that the construction of environmentally friendly rocket-cosmic complex Zenit of reaserch drafring department (RDD) “Pivdenne” and at production association (PA) “Pivdenmash” is the world level progress. A double-stage LV version Zenit-2, LV carries onto low circular polar orbit the useful weight up to 13,7 t. A three-stage LV version Zenit-3SL that is used in international Sea Launch project provides an orbital injection of spacecrafts up to 2,7 ton mass to geostationary orbit, spacecrafts up to 6 ton – to transfer to geostationary orbit, spacecrafts of 11-15 ton – to low earth orbit. The LV Zenit-3SL includes a double-stage launch vehicle Zenit-2S, upper-stage rocket DM-SLat the third stage, by space rocket complex (SRC) “Energiya” production and the block of useful load by company “Boing” development.

There are plans to modernize this space rocket complex to solve problems of starts: for launches near-earth orbit of satellite mass up to 12 ton (LV Zenit-2SLB), for launches to transfer to geostationary orbit of satellites up to 3,75 ton (LV Zenit-3SLB). The project is developed under the aegis of “Sea Launch”enterprise. The managment of works is perfomed by Ukrainian-Russian company “International space services”, RDD“Pivdenne”, PA “Pivdenmash”, drafting department (DD) of transport machine-building (Russia), SRC “Energiya”, the Center of earth space infrastructure operation.

The joint Ukrainian-Brazillian project “Tsyklon-4” (fig. 3) stipulates the development of new competetive, long term usage oriented rocket space complex Tsyklon-4 and building of ground infrastructure at subequatorial starting centre Alkantara in Brazil. The energy capabilities of launch vehicle Tsyklon-4 will allow to carry spacecrafts of mass up to 5,7 ton into low equatorial orbit, spacecrafts of mass up to 1,7 ton onto transfer to geostationary orbit.

It should be noted that the availability of reliable navigation information aboard ground moving objects, specifically armour, allows to solve successfully the problems of march navigation, topographic linkage, also to increase considerably the coordinated actions efficiency of fighting unities of different functional destination: tanks, antiaircraft mortar facilities, artillery etc. The importance of outer target designation, fire manoeuvres and movement (along front and deep down) on the basis of self-contained navigation systems can scarely be overestimated. For the future the construction of complex navigation systems by combining exact inertial and satellite navigation systems should be considered the most perspective.

Navigation information should be continuous, exact with complete data, with protection from disturbers, the invariance to climatic conditions, daily variations etc.

In passing, the accuracy of the inertial navigation systems is influenced by the following factors: angular fuselage rocking, vibration, penetrating acoustic radiation, thermal torch and etc. At the same time, the errors of launch vehicle insertion under the certain circumstances can result in essential time shortening of spacecraft living and contingency occurrence. Summarizing all the information it is arguable that the drawbacks of inertial navigation systems in their aggregate integrally impair perfomance characteristics of moving objects.

Full-scale tests make it possible to state that just during the launch vehicle start the highest level of sound radiation injects into the environment. Part of it penetrates into the fuselage and under the main aerodynamic fairing and amounts to 140-150 decibel. Thus the facilities and systems of inertial navigation, which are allocated right here together with effective load are subject to its influence.

But this source is not the only one. The external layers of boundary layers move in regard to the body of space vehicle airframe with supersonic speed, in the issue the turbulence, which causes the occurrence of concentrated and spherical waves, appears. The strokes drive a new source of noise by interacting with body. This waves are the most dangerous, because they can be sufficiently intense.

Finally, during the LV start of bases mobile location the acoustic field possesses complex structure in consequence of generation of not only direct radiation, but also reflected sound field, specified by reverberations effects. Thus this sound field should be regarded as a diffused.

In the analysis of sound formation question the transparent phenomena aspects should be mentioned. The influence of powerful shock waves in a stream convective zone, temperature discontinuity in the issue of incomplete combustion, turbulence dampening by sound waves and some other not enough meaningful factors are regarded to them.

To sum up we mention that today a rather convincing full-size proof of LV sound major cause in the kind of radiation from side of quadra fields, which move with supersonic speed, obtains. It is fixed that about 0,5 % of contemporary bearers power of driving installations radiates in the form of sound energy.

It was found that the acoustic vibration of surface proper is not the only reason of danger. Wave processes that appear at full-size conditions and apparent fuselage rocking possesses the elastic interaction mechanism, which is considerably differ from standard. Also the mechanical calculation analogs are of another construction. In the foundation of their construction there underlies the proportion between the feature size and the half-wave length of external disturbance. Due to such approach the error structure of inertial navigation systems is appreciably reviewed, in certain cases (for example, the linear acceleration hydro integrator) the modern “surface” view of the pickup signal useful component contents is explained.

The spatial facility character as compared with kinematical and power (vibrations), which penetrates into the devices through its bearings, serves the peculiarity of acoustic load. This fact also stipulates the constructing principle of calculated models. For the first the gyroscope bracket should be considered as a system with distributed parameters unlike to kinematical and force factors influence, when it is enough to regard the bracket as a system with lumped parameters. Besides, when the acoustic influence occurs then the commensurability of feature size and a half-wave disturbance should be defined.

The crossing to calculated models as systems with distributed parameters made a possibility to coordinate the movement of bracket elastic surface (relative motion) with angular motion of base (translational motion) by determination the Koriolis moment of inertial force and the level of its contribution to the occurrence of “inaccurate” angular velocity in the entrance of devices. By the way, thanks to this the const error component of two-stage gyroscope has already been shown up in the first approximation, for example at the anisochronous body rocking unlike to existed calculated model, which didn’t provide it.

From the other side, considering the gyroscope bracket as a system of perfectly rigid bodies, it is naturally also to define the influence of antisymmetric acoustic pressure component in consequence of windage. Analytical relations have allowed to calculate the errors of two-stage gyroscopes under the influence of this factor and also the deviation of three-stage free gyro main axe and hydro integrator main axe. Eventually, the possibility to uncover the detector motion mechanisms of correction systems that at present serve as a source of possible contingency obtains. Due to gyro oneself, it acts as a detector, which is allocated on the triaxial hydro stabilized decking, it became possible to identify the float movement under the influence of through-passing acoustic pressure wave.

We received the following methods of analysis development of inertial navigation system errors for multiphase gyroscope bracket. This permits to numerically estimate the level factor, for example, the cavitational demonstrations of liquid phase part, how they influence the devices errors.

One of our aims is to receive the partial model, but well-known among the calculated models.