Gyroscopy and Navigation最新文献

Abstract—In the paper, simulation is used to study the thermal deformation of Q-flex accelerometer quartz sensitive element (SE) with technological geometrical deviations of elastic beams with conductors within the operation temperature range. It has been shown that the largest bending moment in the SE appears when conductors from the front and back sides of elastic beam have different thickness and width. A method for static thermal tests simulation has been developed, which allows estimation of accelerometer zero shift with account for the geometrical imperfections of SE elastic beams. It has been revealed that the thermal hysteresis and non-repeatability of accelerometer zero shift are due to the plastic deformation of conductors under near-boundary temperature loads. A SE modification with loose conductors has been developed, which, according to the simulation results, improves the thermal coefficient, hysteresis, and repeatability of zero shift.

Abstract—

To produce a 3D map of the Tehran’s first gas transfer pipeline (Tehran—Kuhnamak), a methodology has been developed in this research, in which a strapdown inertial navigation system (SINS) based on micro-electro-mechanical system (MEMS) and inertial measurement unit (IMU) is applied on pipeline inspection gauges (PIGs) to sense data every 4 millimeters of 111 kilometers of the whole pipeline. The navigation solution is based on an extended Kalman filter (EKF) using Allan variance (AVAR) to analyze and tune the EKF initial inputs. A new constrained PIG filter (CPF) is proposed in this paper in integration with EKF, in which two Euler angles (pitch and yaw) of the PIG are updated due to non-holonomic state constraints between pipe junctions. Besides, 98 magnetic control points have been used to increase robustness about every kilometer, which is coordinated by GPS. Furthermore, odometer measurements have been employed as measurements in the EKF. The results show that using such a hybrid approach has improved the PIG positioning accuracy by about 81% compared with that of the Basic EKF. In addition, positioning accuracy in comparison with the latest methods like EKF/pipeline junctions (PLJ) has increased by 32%. Furthermore, the proposed method is 55% better than EKF/PLJ in the algorithm runtime.

Abstract

Phase-Locked Loops (PLL) may be included into modern MEMS gyroscopes to provide excitation of inertial mass oscillations, as well as to form clock signal for digital signal processing in an integrated circuit. This paper considers the impact of PLL architecture on MEMS gyroscope performance and its estimation. It is shown that the proposed Double Sampling Phase-Locked Loop (DSPLL) architecture makes it possible to improve the accuracy of MEMS gyroscopes due to high synchronization rate, as well as higher frequency stability as compared to the widely used Charge Pump Phase-Locked Loop (CP-PLL) and the Sampling Phase-Locked Loop (SPLL).

Abstract

The article is devoted to the development and application of control moment gyroscopes used for active triaxial attitude control of spacecraft. These gyroscopes belong to the class of inertial actuators, which also includes flywheel control motors, gyro dampers, and passive gyrostabilizers. A distinctive feature of control moment gyroscopes (CMG) is the presence of special drives that control the rotation of the gyroscope relative to its suspension axes. By regulating the speed of this rotation, the drive creates the required control moment. The paper describes the main development stages of Russian CMG and systems based on them, the features of their design and architecture, application issues and development trends.