The fiber-optic gyroscope started to be investigated in the mid 70’s, opening the way for a fully solid-state rotation sensor. It was firstly seen as limited to medium-grade applications, but today, it reaches ultimate theoretical performance and surpasses its well-established competitor, the ring laser gyroscope, in terms of bias noise and long-term stability.

The article considers the effect of temperature changes on the output of closed-loop fiber-optic gyroscope (FOG) developed by Concern CSRI Elektropribor, JSC. Hardware and algorithmic methods to reduce this effect are proposed, including compensation of multiplicative and additive errors caused by temperature changes, and various thermal stabilization options. These methods reduce FOG temperature drifts by 1-2 orders of magnitude.

In strapdown INS (SINS) the yaw angle is always determined as a sum of two angels: the “platform” azimuth and the gyro yaw. The numerical values of each of these angels, whose sum stays equal to the current yaw of an aircraft, can indeed be variables. These values depend on initial alignment of azimuth angle and on the trajectory of the aircraft’s preceding movements. This article is dedicated to the analysis of this variability and the ways it could be taken into account in the azimuth correction algorithms.

Existing high-accuracy aircraft navigation systems are based on inertial navigation systems integrated with aiding systems. An aiding system can be represented by an RGB color vision-based correlation-extremal navigation system (CENS).

The article describes the algorithm for consideration of air condition when making the color photos for reference images and the algorithm for synthesizing the reference images of one season using the color photos of the other season to be applied in color vision-based CENS.

The paper presents a loosely coupled approach for the improvement of state estimaion in autonomous inertial navigation, augmented via image_based relative motion estimation. The proposed approach uses a novel pose estimation technique based on the minimization of an entropy like cost function which is robust by nature to the presence of noise and outliers in the visual features. Experimental evidence of the performance of this approach is given and compared to a state of the art algorithm. An indirect Kalman filter is used for navigation in the framework of stochastic cloning. The robust relative pose estimation given by our novel technique is used to feed a relative position fix to the navigation filter. The simulation results are presented and compared with the results obtained via the classical RANSAC based direct linear transform approach.

This paper deals with the problem of mobile robot navigation in cluttered environment. Adaptive elliptic trajectories are exploited for reactive obstacle avoidance using only position information and uncertain range data. The obstacle avoidance strategy used is based on the elliptic limit-cycle principle where each obstacle is surrounded by an ellipse. The ellipse parameters are computed online using a sequence of uncertain range data. An online heuristic method combined with the ex-tended Kalman filter (EKF) is used to compute the ellipse parameters. It is demonstrated that this process ensures that all range data are surrounded by a computed ellipse. Moreover, this paper proposes a single control law to the multicontroller architecture where a reactive obstacle avoidance algorithm is embedded. The proposed control law is based on the Kanayama control law; it is designed to im-prove the performance of the controllers. The stability of this control architecture is proved according to the Lyapunov synthesis. Simulations and experiments in different environments have been performed to demonstrate the efficiency and reliability of the proposed online navigation in cluttered environment.

The paper investigates how sampling period affects the modal controllability and stabilizability of a sampled-data submarine motion control system. Systems with a computation delay using generalized DAC as a digital-to-analog converter are considered. A set of pathological periods, when the system may turn unstabilizable, is constructed. Selection of a sampling period for a system with first-order extrapolator and interpolator is shown by a numerical example.

The paper presents a method for offloading CPU of SNS receivers. The idea is to save CPU resources through decimation of IF readings in signal processing. The method was applied in software correlator of space-qualified MosaicGNSS re-ceiver and in GPS/GLONASS receiver for consumer market by Mstar Semicon-ductor (Taiwan) to improve its performance.