To avoid the difficulties in fixing the carrier phase ambiguities, the time difference carrier phase approach is applied to a GPS/IMU tightly-coupled navigation system to eliminate the ambiguity between two successive GPS epochs, which can provide high velocity estimation accuracy. The carrier phases are carefully corrected before use. A modified method is proposed by using the system matrix in each time up-date to calculate the integration of the velocity errors in the measurement update equation. A Cubature Kalman Filter (CKF) is applied to the integrated navigation system to improve the attitude estimation accuracy. The navigation result and comparison show the accuracy improvement after applying the carrier phase corrections, modified measurement update method and the CKF.

The paper considers attitude determination, including true heading, by an integrated orientation and navigation system (IONS) comprising an inertial measurement unit (IMU) based on MEMS sensors and multi-antenna GNSS receiving equipment. The paper studies the algorithms and errors of IONS in solving the attitude determination problem using the phase measurement data of two-antenna GNSS module with an antenna base within the wavelength of the satellite signal at carrier frequency. Here, IMU with GNSS antenna base performs autocompensation rotation. The efficiency of using GNSS phase measurements with short rotating antenna base for estimation of heading errors is analyzed.

The IONS experimental sample uses IMU based on STIM300 Sensonor MEMS sensors (Norway), and phase measurements by GNSS receivers 1К-181 “RIRV”(Russian Institute of Radionavigation and Time) (Russia ). The results ob-tained in bench tests are presented.

This paper presents an approach to navigation system’s position and heading correction using building floor plans. The algorithm includes three steps: autonomous sensors data processing to obtain position and heading, map- matching correction, and navigation system errors estimation. A particle filter is used to incorporate the building plan information and a Kalman filter estimates the dead reckoning error states. This algorithm was designed for vehicle navigation systems operating inside buildings with known floor plans and can be adapted for implementation on real-time navigation systems using low-cost MEMS gyroscope and speed sensor as dead reckoning instruments. The real-world data collected from the vehicle indoor tests has shown that the proposed algorithm is able to correct significant errors in dead reckoning position and heading by applying the map constraints.

The article describes an open-loop fiber-optic gyro (FOG) with digital output and high scale factor stability. This is achieved by stabilization of rotation signal amplitude and phase modulation depth. The article studies the FOG with two closed feedback loops; the method to suppress the deadband is considered. The article de-scribes the method of reducing the time required to start operation of the FOG with both open primary loop and closed feedback loops by means of their output characteristic correction. A method of compensating the parasitic effect in phase modulators of optical ICs is proposed as the further prospect for improving the FOG accuracy.

A procedure for balancing the four lower harmonics of inhomogeneous angular mass distribution for the quartz toothless hemispherical resonator gyroscope using the chemical etching technology is proposed. Chemical removal of unbalanced mass from the surface of the resonator partially immersed into the chemical bath is conducted in accordance with the analytical algorithm for calculating the angle of rotation about the axis of symmetry of the resonator, its inclination and depth of immersion, and the time of chemical etching (Figs. 1 and 3). Balancing the harmonic number N is realized by immersing the resonator into the bath N times with its sequential rotation by the angle 2π/N around the symmetry axis. An example of balancing the third harmonic of the quartz hemispherical resonator gyroscope is presented. It is shown that the proposed technique can significantly reduce the balancing time and complexity of balancing in comparison with the method of ion-plasma etching.

A new mathematical model of a gyro is constructed. The model describes interrelated electrical and mechanical oscillations with the existence of electrode voltage. Wave pattern of the resonator oscillations was investigated using the asymptotic method of Krylov – Bogolyubov averaging. It is shown that nonlinearity of electric processes in the resonator control loop results in additional gyro errors. A numerical example is given.

A method to account for size effect in SINS calibration is proposed. The method uses Kalman filter in SINS inertial mode and estimates the calibration errors for accelerometers, gyros, and accelerometer proof mass positions. The method does not depend on a specific calibration scenario, does not require analytical calculations, and calibrates size effect simultaneously with other SINS parameters in common iteration procedure.

Principal Russian technologies in the sphere of power gyroscopic systems for spacecraft attitude control systems are presented since the emergence of this technology till the present time. Design and circuit features, specifications of the up-to-date power gyroscopic systems are described. Scientific and technical solutions are considered, which critically improve dynamic and accuracy parameters of new solutions. The principles of designing the modern power gyroscopic systems and prospects of their development are summarized.

The paper focuses on improving the positioning accuracy of single-frequency GNSS equipment by using GEMTEC, a new model of total electron content of ionosphere. The model is tested compared to the standard method applying Klobuchar model.

The article studies the use of splines for real-time generation of smooth executive paths that makes it possible to decrease a value of control signal, when changing from one elementary path section to another, and to create the control margin.