R. Katoch, P. R. Mahapatra||
GPS based attitude estimation of aircraft using neural network aided Kalman filter||
This paper shows how a neural network can augment the Extended Kalman filter (EKF) in attitude estimation of the aircraft using GPS. The carrier phase of GPS is used to estimate the attitude information of an aircraft. The typical problem of attitude determination using GPS is a non-linear function of the attitude angles. Conventionally Extended Kalman Filter is used for attitude estimation. The adaptive capability of the Kalman Filtering is known to improve by incorporating the Neural Network in the normal Kalman filter. A Radial Basis Function Network (RBFN) is subsequently employed to aid the EKF in attitude estimation. The study is extended to compare the error reduction and estimation improvement in attitude parameters under the influence of measurement and bias error. The performance of the filter during the transient phase of satellite change over is also analyzed.
A.A. Odintsov, V.B. Vasilyeva, Yu.E. Naumov||
The use of two inertial systems of semianalytic type with different gyrostabilized platform control laws in azimuth for improving accuracy of navigation parameters generation||
Operation of two inertial navigation systems of semianalytic type is considered. In one of them gyrostabilized platform (GSP) forcedly rotates around vertical axis, in the other it has geographic orientation. The analysis carried out on error equations of both INS shows that use of their laws of variation in INS operation together with different GSP control laws in azimuth can significantly improve accuracy of navigation parameters generation: can correct constant error of heading generation by INS-G (INS with geographic orientation) basing on heading generated by INS-R (INS with forced rotation), can compensate oscillating terms of errors in INS-R leaning upon output parameters generated by INS-G, can reduce error growth in longitude in both INS-R and INS-G data smoothing at the cost of different signs of proportionality constant at gyroscope control system scale parameter deviation.
Ya.I. Binder, A.E. Eliseenkov, T.V. Paderina, V.G. Rozentsvein||
Small-sized gyro inclinometers: problems, development concept, results of development and implementation||
The results of development and implementation of cable small-sized gyro inclinometers ำรศ-42 at the mining enterprises of Karelia and North-East region of Russia are presented. Basing on the accumulated experience, a crucially new kinematic scheme of a strapdown gyro inclinometer called "diametrical" was proposed, which allows achieving its implementation in continuous and point-to-point operating modes for any arbitrary borehole trajectory.
L.V. Afanasyeva, E.A. Boyarsky, V.N. Koneshov, I.E. Stepanova||
Analytic continuation of the gravity field upward and downward at airborne gravity measurements processing and Analysis||
Modern aerial navigation technique allows usage of airborne gravity measurements for the geophysical prospecting. For the first time such up-to-day experiments in Russia were commenced in 1997-1998. A profile across quite complicated gravity field was measured with accuracy of about 1 mGal. A need arises to set up some metrological area as a base to test both measuring means and mathematical filters, as well algorithms for the gravity field upward and downward continuation. Analytic approximation of the gravity field at zero height, obtained from surface measurements, was continued upward to some possible heights of flight. Sources of uncertainty in atop values were analyzed. The average estimated accuracy of the upward continuation is of 0.1-0.2 mGal, provided surface data being errorless.
The downward continuation of the gravity field has been build with the help of the S approximation method based upon the representation of a harmonic function by the sum of single- and double-layer, see (6). It is shown that the gravity field can be restored with relative accuracy of about 2 percent. The two-height measurements allow the approximation of the Earth's gravitational field at the margins of the area under investigation.
The prospects for creation of microoptical gyroscope||
The article is deducted to analyses of results of microoptic gyro development. The possible schemes of microoptic gyros are considered. The main ascent is made on the consideration of scheme with passive ring cavity. The values of parameters necessary for provision of gyro drift on the level of 1 deg/h are estimated. The questions of technology features connected with the development of passive ring cavity on the base of wave guide are considered. On the base of obtained results the conclusions is made on prospect of development and implementation of microoptic gyro.
Topical issues of designing strapdown inertial navigation system attitude algorithms. Part 2: Frequency extension of the algorithms application area||
The paper deals with a problem of attitude algorithms extension for high frequency base vibration. Presented here are the general formulations of the techniques that lead to the residual drift error minimization in extended frequency range. It is shown, that the problem of coning-algorithms sensitivities to the in-phase component of vibration can be solved by applying an additional optimization CB-technique that resulted in efficient algorithm structure, with only two cross products appearing explicitly in the algorithm equation.
K.V. Polyotkin, N.G. Troitsky, A.I. Chernomorsky||
Reduction of temperature drift of rate sensor based on rotor vibratory gyroscope of compensatory type||
Methods for reduction of temperature drift of zero signal of rate sensor (RS) based on rotor vibratory gyroscope (RVG) of compensatory type are considered. A simplified mathematical model describing RS zero signal temperature drift dependence on RVG parameters has been developed on the basis of experimental research.
V.I. Gavryusev, A.G. Shcherbak, S.N. Belyaev||
Analysis of microflow processes caused by diffusion welding of electrostatic gyroscope beryllium rotors||
Diffusion welding in vacuum (DWV) of two beryllium hemispheres of a hollow rotor for electrostatic gyroscope is conducted with closely fitting compression molds. DWV welding entails rotor shape deformation and this in turn is a serious handicap to rotor manufacturing. Analysis of thermomechanical cycle of welding shows that the shape deformation is caused both by nonuniform distribution of loads on hemispheres when DWV welding is conducting and by anisotropy of rotors temperature broadening (Fig. 2) and by considerable polythickness in a meridional direction as well. Mathematical model of thermomechanical cycle of DWV welding shows that the influence of the three above mentioned negative factors on the rotor shape deformation when the rotor is DWV welding can be reduced. It can be reached by specifying allowance for the outer diameter of the hemispheres to reduce their polythickness (Fig. 3, 4) and by creating ellipsoidal body cavity of compression molds through the use of a design height ring insert installed between the faces of the compression molds (3).
Proceedings of the 13th Saint Petersburg International Conference
on Integrated Navigation Systems
International Public Association
The Academy of Navigation and Motion Control
Devoted to the 90th anniversary of the birth of S.S.Rivkin||
The 21nd General Meeting of the Academy of Navigation and Motion Control||
R. Kalman in Saint Petersburg||
On the conference PLANS 2006||
Adaptive and intelligent systems of information control and processing||
Russian and international conferences, symposia and exhibitions||