This paper presents an innovative bulk magnetostrictive actuator made of a 2V-Permendur alloy rod, capable of functioning across multiple deformation modes—longitudinal, torsional, and flexural. In longitudinal mode, displacement is produced by the Joule effect, where a magnetic field applied along the rod’s axis, generated by a surrounding coaxial coil, induces deformation along its length. Torsional mode activation follows the Wiedemann effect, wherein an electric current passed directly through the rod produces a circumferential magnetic field that twists the material. Additionally, flexural deformation is achieved by a special designed magnetic core that directs a magnetic field to the rod’s surface, producing bending movements along the rod’s length. The actuator operates using controlled DC magnetic fields. Experimental results demonstrated outstanding performance, with maximum displacements reaching 12 microns in longitudinal mode, 7 microns in flexural mode, and 0.15 degrees in torsional mode. Such multi-functional performance highlights the actuator’s potential in precision POSITIONING SYSTEMs, with particular suitability for advanced microscopy, optical instrumentation, and other fields requiring sub-micrometer POSITIONING accuracy.

The paper presents a kinematical model for a random POSITIONING SYSTEM which simulates microgravity conditions on the ground. The random POSITIONING SYSTEM contains two frames, with an experiment platform. The frames are rotated around two perpendicular axes by a random angular velocity that it causes continuous changes in the orientation of experimental sample relative to the gravity's vector. The angular velocity between random values is changed based on specific function in order to limit the generated spurious acceleration below a preselected threshold. The kinematical model yields criteria to evaluate the microgravity conditions on ground base. Such criteria are defined based on the mean values of acceleration and gravity components which are sensed by the rotating experimental sample.

In this paper, the cruise missile’s DSMAC POSITIONING SYSTEM is simulated based on correlation. Then, in order to create a disturbance and analyze the effects of each disturbance in the performance of this POSITIONING SYSTEM, items such as changing image resolution, brightness, ambient coverage, viewing angle and other random variables such as artificial changes (smoke) were used. In order to determine the area of defense operation against this SYSTEM, considering the missile inertial navigation SYSTEM error and the possibility of circular error (CEP), it has been proved that the DSMAC location is within a radius of three to five kilometers from the target. By analyzing the obtained results, it has been shown that the areas with more black pixels, such as forest areas, are undesirable areas for DSMAC. In addition, by using jamming in the cruise missile altimeter SYSTEM, the accuracy of the missile altimeter process can be reduced so that the image POSITIONING SYSTEM is completely disrupted. Also, the larger the size and area of the total artificial changes (smoke) and the color of the changes, in proportion to the background of the image, the disruption and defense against the DSMAC SYSTEM will be possible. Finally, by providing operational scenarios, the defense against the cruise missile DSMAC POSITIONING SYSTEM has been realized.

Today, POSITIONING has attracted special attention as one of the fundamental aspects of various SYSTEMs. Over time, the navigation SYSTEM's error, especially in the Inertial Navigation SYSTEM (INS), has significantly increased. This error increase can lead to serious issues in navigation processes, especially on long routes. To ensure the high accuracy and stability of navigation on long routes, the use of advanced and effective auxiliary SYSTEMs is necessary. The goal of this article is to present an innovative method for POSITIONING by combining camera and inertial sensor data to enhance accuracy in this vital process. This method is particularly important in self-driving vehicles, domestic robots, and search and rescue robots operating in enclosed environments or areas without active GPS coverage. Consequently, there is a crucial need for a real-time POSITIONING SYSTEM for these SYSTEMs. In this article, we have implemented a real-time Visual-Inertial Odometry (VIO) navigation SYSTEM on a PC platform, which performs significantly better than the INS SYSTEM alone. In this SYSTEM, cameras are used to correct the accumulated INS error, and the fusion of cameras and inertial data is done using a graph. To validate and evaluate the SYSTEM, practical data collected by the SYSTEM are used, demonstrating that the proposed VIO SYSTEM exhibits more than a 90% improvement compared to INS.

The rapid displacement of the ocean floor during large ocean earthquakes causes the propagation of tsunami waves on the surface of sea and gravity waves in the atmosphere. Gravity waves are buoyancy oscillations that can propagate both horizontally and vertically and their propagation is affected by the gravity force of the earth. Gravity waves pierce the ionosphere layer after passing through the troposphere layer. In addition to transferring energy to the ionosphere, they cause significant changes in ionospheric parameters, as a result they have significant effects on the propagation of radio waves through this dispersive medium. In this study, twofrequency measurements of the Global POSITIONING SYSTEM (GPS) and ionosonde were used to determine the duration and effect of ionospheric perturbations in response to the tsunami induced by the 2011 Tokyo earthquake. The critical frequency of the F2 layer (fof2) data also showed clear disturbances that were consistent with GPS observation. Furthermore, gravity waves and tsunami waves have similar propagation properties, so gravity waves can be used for tsunami warnings. In order to further investigate the spatial variation in ionospheric electron density (IED) the satellite ionospheric electron density profiles of FORMOSAT-3/COSMIC were used for both reference and observation periods. The reduction in IED started from 200km and continued up to 272km altitude, and the maximum reduction was 2. 2×105 el/cm3 that has happened in the 225 km altitude. The IED increased up to 767 km altitude continuously in which the maximum increase was 3. 92×105 el/cm3 in 357 km altitude.

Using the conventional methods to integrate the inertial navigation SYSTEM and the global navigation satellite SYSTEM by the extended Kalman filter depends on a time consuming algorithm to determine relatively accurate initial values. In the presence of large initial error, EKF will diverge or converge slowly due to the dependence of the Jacobians on the state variables values. The invariant extended Kalman filter has the ability to solve this problem by changing the error definition method and using the theory of invariance, in which the convergence does not depend on the error of the initial values. In this paper, in order to remove the initial alignment phase, the IEKF is used to integrate the inertial navigation SYSTEM and the global POSITIONING SYSTEM. Considering the navigation variables as elements of a Lie group, the error dynamics can be presented in such a way that the Jacobians are independent of the state variables. The comparison of the integration results using the invariant extended Kalman filter, the standard extended Kalman filter and the error state extended Kalman filter with experimental data set in different initial errors shows the significent performance of the invariant Kalman filter than the other filters and its ability to resolve the divergence or slow convergence problem of the conventional methods. The results show, the dependence of the integration method on the time consuming initial alignment can be removed using this filter.