Transfer Alignment Research Articles

Analysis of Alignment Accuracy due to Velocity/Attitude Error of Master Inertial Navigation System in Velocity/Attitude Matching Transfer Alignment

This paper theoretically analyzes the effect of the velocity and attitude errors of Master Inertial Navigation System(MINS) on the accuracy of Slave Inertial Navigation System(SINS) transfer alignment in velocity and attitude matching, and validates the analysis through simulation. Theoretical analysis involves deriving a new state equation that considers the velocity and attitude errors of MINS from the state equation of the transfer alignment filter, and deriving the state estimation equation of the Kalman filter based on this. The analysis confirms that MINS's velocity and attitude errors induce the same level of velocity and attitude errors in SINS. A reference inertial navigation system model is added to the simulation model, and the transfer alignment accuracy is analyzed by comparing the navigation information of MINS and SINS with the reference inertial navigation system. It is confirmed that the accuracy analysis results through simulation are consistent with the theoretically analyzed results, and through this, the validity of the theoretically analysis in this paper is verified. The research findings indicate that when performing transfer alignment using MINS, which is likely to be operated for prolonged periods in pure inertial navigation mode, the navigation errors of MINS are transferred to SINS. This implies that initial correction navigation is necessary to be considered for SINS

Efficient Large-Area (81 cm2) Ternary Copper Halides Light-Emitting Diodes with External Quantum Efficiency Exceeding 13% via Host-Guest Strategy.

Ternary copper (Cu) halides are promising candidates for replacing toxic lead halides in the field of perovskite light-emitting diodes (LEDs) toward practical applications. However, the electroluminescent performance of Cu halide-based LEDs remains a great challenge due to the presence of serious nonradiative recombination and inefficient charge transport in Cu halide emitters. Here, the rational design of host-guest [dppb]2Cu2I2 (dppb denotes 1,2-bis[diphenylphosphino]benzene) emitters and its utility in fabricating efficient Cu halide-based green LEDs that show a high external quantum efficiency (EQE) of 13.39% are reported. The host-guest [dppb]2Cu2I2 emitters with mCP (1,3-bis(N-carbazolyl)benzene) host demonstrate a significant improvement of carrier radiative recombination efficiency, with the photoluminescence quantum yield increased by nearly ten times, which is rooted in the efficient energy transfer and type-I energy level alignment between [dppb]2Cu2I2 and mCP. Moreover, the charge-transporting mCP host can raise the carrier mobility of [dppb]2Cu2I2 films, thereby enhancing the charge transport and recombination. More importantly, this strategy enables a large-area prototype LED with a record-breaking area up to 81 cm2, along with a decent EQE of 10.02% and uniform luminance. It is believed these results represent an encouraging stepping stone to bring Cu halide-based LEDs from the laboratory toward commercial lighting and display panels.

CONCEPTUALIZING E-GOVERNMENT INITIATIVES: LESSONS LEARNED FROM AFRICA-US COLLABORATIONS IN DIGITAL GOVERNANCE

This review paper explores the dynamics, challenges, and successes of Africa-US collaborations in e-Government, highlighting the significant impact of digital governance initiatives on improving public service delivery and governance. Through an examination of theoretical frameworks, key concepts, and contextual differences, the paper synthesizes lessons learned and best practices from these international collaborations. It identifies critical success factors, including leadership, stakeholder engagement, and capacity building, while also addressing common challenges such as the digital divide and technological infrastructure. Emerging trends such as artificial intelligence, blockchain, and digital identity systems offer new avenues for future collaborations. The paper concludes with recommendations for strengthening these partnerships, emphasizing the importance of technology transfer, policy harmonization, and sustainable development goals alignment. Keywords: E-Government, Digital Governance, Africa-Us Collaborations, Technology Transfer, Digital Divide, Emerging Technologies.

A high-accuracy system model and accuracy evaluation method for transfer alignment

With the increasing demand for high-accuracy navigation, distributed payloads put forward higher requirements for the initial alignment accuracy of their equipped slave inertial navigation systems (INSs). However, the existing transfer alignment models have poor compensation effect on flexible deformation, resulting in low alignment accuracy. Moreover, these models cannot accurately evaluate the accuracy of transfer alignment due to ignoring the errors of the master INS. To address these two problems, a new high-accuracy transfer alignment system model is established by comprehensively considering errors of the master and slave INSs. Further, the propagation characteristics of the master and slave inertial sensor errors in transfer alignment are analyzed, and the relationship expression between the master and slave inertial sensor accuracy and the transfer alignment accuracy is derived. Thus, the accuracy of transfer alignment can be pre-evaluated according to the master and slave inertial sensor accuracy. The experiment results show that the alignment accuracy of the proposed method is improved by more than 71.56% compared with the traditional methods, and the relative errors between the proposed accuracy evaluation method and the Monte Carlo simulations are less than 9.14%. Thus, the correctness, effectiveness and superiority of the proposed method are verified.

Study on the method of transfer alignment based on the distributed inertial network of guided submunition

Aiming at the problem of poor transfer alignment accuracy between missiles with a high length-to-diameter ratio as a carrier missile and the internally carried guided submunition, this study proposes a transfer alignment method based on the distributed inertial network of the guided submunition. Initially, considering the influence of the deflection deformation of the carrier missile body and the dynamic nonlinear deformation of the lever arm on the transfer alignment accuracy, the corresponding error model is established and compensated for the sub-inertial guide velocity to improve the accuracy of the observed quantities. Additionally, in response to the high failure rate of low-cost inertial guidance systems equipped with guided submunition, we used an inertial network data fusion architecture based on the isolation of device failure monitoring, which effectively isolates the faulty data through the fusion of inertial measurements at the sensor level and optimal fusion of filtering to further improve the reliability of transmission alignment. The effectiveness of the method proposed in this paper is verified through a large number of simulation experiments. Compared with the traditional transfer alignment method between a single master inertial guide and a sub inertial guide, the method in the paper has obvious improvement in the transfer alignment accuracy. In addition, this method is not affected by the failure of inertial devices in the distributed inertial network, and can continuously maintain a high transfer alignment accuracy. For this kind of missile-borne distributed inertial network with a sub-node sets layer, it is found after comparison that: the transmission alignment error is basically the same for different slave nodes in the same sub-node sets; between different sub-node sets, the closer to the master inertial guide the transmission alignment error is smaller. This study provides a new solution idea and certain reference value for solving the problem of poor transfer alignment accuracy between missiles with a high length-to-diameter ratio as a carrier missile and the internally carried guided submunition.

Transfer alignment method based on installation deviation angle estimation for array POS

Transfer alignment of array Position and Orientation System (POS) is the key technology to provide motion information for airborne earth observation high-precision imaging. Because the large deviation angle between main Inertial Measurement Unit (IMU) and slave IMU is difficult to accurately measure by existing methods, the transfer alignment accuracy will be seriously affected. Aiming at this issue, a transfer alignment method based on installation deviation angle estimation for array POS is proposed. This method includes two steps: pre-estimation and improved transfer alignment. First, two deviation angles are calculated by angular velocity and acceleration using quaternion optimization method respectively. The higher-precision deviation angle is fused by two deviation angles using their respective weights, which are calculated by Signal to Noise Ratios (SNRs). Second, the result of pre-estimation is used in transfer alignment. Residual errors of deviation angle are considered as state variables and be compensated online. Compared with the existing methods, the velocity, position and attitude errors calculated by this method are reduced by 15.4%, 31.7% and 66.5% respectively. The proposed method significantly reduces the adverse effect of installation deviation angle on measurement accuracy of array POS.

Comparison of Filtering Techniques for Transfer Alignment of Air Launched Tactical Guided Weapons

The transfer alignment technique is very useful for the accurate initialization and calibration of gyroscopes and accelerometers of INS for air-launched tactical guided weapon systems. In the present war scenario, the initialization of INS should be accurate and rapid to launch the tactical weapon against air or land targets within the shortest available time. A lot of development has been carried out by researchers for INS transfer alignment in the field of state estimation. The study and method presented in the research are relevant to aerial launch vehicles. However, to meet present guidance requirements within less time for initializing weapons, more appropriate transfer alignment algorithms are needed. This paper discusses the relative performance of Kalman Filter (KF), Extended KF, and Unscented KF for aligning the weapon INS using the data from Master INS. New developments, limitations, applicability, and design methods for the Kalman filters, became a key component in the transfer alignment of air-launched tactical missiles. These methodologies are extensively utilized in Navigation and Control systems; therefore, this research work will be an informative and perfect guide to existing and potential readers.

Parameter transfer and Riemannian space coordinate alignment for EEG intention recognition

In brain-computer interface (BCI) system, local and temporal information of brain signals are often distorted and different subjects are variable, which leaves the brain-computer interfaces based on motor imagery (MI) challenging in cross-subject variability. This paper proposes a novel transfer learning method and a data alignment algorithm based on Riemannian space to reduce the difference between subjects. Through these methods, the target classification parameters will be close enough to that of the previous subjects which have a similar feature distribution to the target one. Therefore, even when only small amount of subject-specific trials of current target subject are labeled, the classification accuracy will not be compromised. The proposed two algorithms are evaluated using three motor imagery EEG data sets. Furthermore, an intelligent wheelchair steering system is designed based on the proposed algorithms. The experiment results show that in contrast with the subject-specific classifier, the proposed approaches achieve greater cross-subject classification accuracy. Moreover, the improvement is more salient when there are fewer trials available for the current target subject. In addition, the two algorithms proposed in this paper are combined to obtain optimal results.

Institutionalizing Innovation: From Pilot to Scale for Co-Packaged Oral Rehydration Salts and Zinc-A Case Study in Zambia.

We document the development and institutionalization in Zambia of a health innovation for diarrhea treatment aimed at children aged younger than 5 years: a unique oral rehydration salts and zinc (ORSZ) co-pack. Seven recommendations from the World Health Organization/ExpandNet are used retrospectively to analyze and describe the successful scale-up of this innovation from its concept stage, including in-country expansion and policy, institutional, and regulatory changes. The 7 recommendations comprise using a participatory process, tailoring to the country context, designing research to test the innovation, testing the innovation, identifying success factors, and scaling up. The scale-up of co-packaged ORSZ in Zambia is shown to be sustainable. Five years after donor funding ended in 2018, an independent, local manufacturer continues to supply the private and public sectors on a commercially viable basis. Furthermore, national coverage of ORSZ increased from less than 1% in 2012 to 34% in 2018. A key success factor was the continuous facilitation over 8 years (spanning planning, trial, evaluation, and scale-up) by a learning and steering group chaired by the Ministry of Health, open to all and focused on learning transfer and ongoing alignment with other initiatives. Other success factors included a long lead-in of inclusive initial consultation, ideation, and planning with all key stakeholders to build on and mobilize existing resources, knowledge, structures, and systems; alignment with government policy; thorough testing and radical review of the product and its value chain before scale-up, including manufacture, distribution, policy, and regulatory matters; and adoption by the government of a co-packaging strategy to ensure cases of childhood diarrhea are treated with ORSZ. With appropriate local adaptations, this approach to scale-up could be replicated in other low- and middle-income countries as a strategy to increase coverage of ORSZ and potentially other health products.

Facilitating Charge Transfer and Band Alignment in Perovskite Solar Cells via Interfacial Regulation with Nb2CTx MXene Oxidized Derivative

Interface engineering to enhance carrier extraction and transfer capability, as well as controlling the morphology and defects of perovskite films remains imperative challenges in perovskite photovoltaics. Herein, we introduce an...

Fault diagnosis of bearings using a two-stage transfer alignment approach with semantic consistency and entropy loss

Fault diagnosis of bearings using a two-stage transfer alignment approach with semantic consistency and entropy loss

Transfer Alignment Design Using a Gyro-free Inertial Navigation System

Transfer Alignment Design Using a Gyro-free Inertial Navigation System

Surface termination control of charge transfer and band alignment across a semiconductor–crystalline-oxide heterojunction

Surface termination control of charge transfer and band alignment across a semiconductor–crystalline-oxide heterojunction

Rapid and Accurate INS Transfer Alignment for Air Launched Tactical Missile Using Kalman Filter

An Inertial Navigation System (INS) independently measures the Position, Velocity, and Attitude (PVA) of thevehicle to navigate it towards the target. Since INS is a dead-reckoning system, it requires accurate initialization toprovide the navigation (PVA) solution. In the case of an air-launched tactical missile, the aircraft navigation system(Master INS) information is used to initialize accurately the missile INS (Slave INS). Rapid transfer alignment isneeded in today’s combat operation to converge slave INS initialization in the shortest possible time using aircraftnavigation information. The transfer alignment consists of first initializing the missile INS and establishing anavigation solution (PVA) using the missile IMU rates and accelerations, then a Kalman filter is used to, estimatethe errors between the Slave INS and Master INS. The proposed method’s simulation results show that a tacticalmissile INS can be aligned to an acceptable accuracy in a very short time based on the aircraft’s attitude information and with natural maneuvers experienced during aircraft take-off.

First-Principles Study on the Selective Detection of Toxic Gases by 2D Monolayer PdS2: Insight into Charge Transfer Dynamics and Alignment of Frontier Molecular Orbitals

First-Principles Study on the Selective Detection of Toxic Gases by 2D Monolayer PdS₂: Insight into Charge Transfer Dynamics and Alignment of Frontier Molecular Orbitals

Design of Transfer Alignment Algorithm with Velocity and Azimuth Matching for the Aircraft Having Wing Flexibility

A transfer alignment is used to initialize, align, and calibrate a SINS(Slave INS) using a MINS(Master INS) in motion. This paper presents an airborne transfer alignment with velocity and azimuth matching to estimate inertial sensor biases under the wing flexure influence. This study also considers the lever arm, time delay and relative orientation between MINS and SINS. The traditional transfer alignment only uses velocity matching. In contrast, this paper utilizes the azimuth matching to prevent divergence of the azimuth when the aircraft is stationary or quasi-stationary since the azimuth is less affected by the wing flexibility. The performance of the proposed Kalman filter is analyzed using two factors; one is the estimation performance of gyroscope and accelerometer bias and the other is comparing aircraft dynamics and attitude covariance. The performance of the proposed filter is verified using a long term flight test. The test results show that the proposed scheme can be effectively applied to various platforms that require airborne transfer alignment.

Theory and practice of hull dynamic deformation law and heading angle transfer error correction

In order to meet the demand of high-precision heading angle transmission in the transfer alignment of inertial navigation system on moving base, the analytical function relationship between the hull deformation and the turning angular velocity and angular acceleration was derived by using the classical beam theory based on the analysis of the equivalent load exerted by the hydrodynamic force and inertia force on the hull structure during the turning process under the combined action of the steering rudder moment and wave force. The objective law between the angular motion and the azimuth deformation angle of the hull under the combined action of maneuvering and sea waves was revealed. Finally, the correction coefficients were determined according to the left turn and right turn motions of the hull by using the measured data of the ship in the sea trial during the S-shape maneuvering navigation, and the azimuth deformation angle correction was completed. The results indicated that the application of the Qu's bending deformation correction formula could greatly reduce the influence of the hull flexural deformation on the heading angle accuracy, meet the needs of high-precision heading angle transmission, and fully verify the correctness of the hull azimuth deformation law and the heading angle transmission error correction theory. This theory and method provided technical support for establishing high-precision distributed digital reference in the field of transfer alignment of inertial navigation on moving base and the application of heading angle transfer of other shipborne equipment.

Multi-Node Motion Estimation Method Based on B-Spline of Array Position and Orientation System

The array position and orientation system (array POS), composed of one main POS and multiple sub-inertial measurement units (sub-IMUs), is key equipment in the aerial remote-sensing system, especially the multi-load system, which can provide motion compensation for the multi-load remote-sensing system to improve imaging quality. Nevertheless, the measurement information of each sub-IMU can only realize the motion information of the corresponding remote-sensing load. Ideally, each remote-sensing load should be equipped with a sub-IMU for motion compensation, which is impossible in actual engineering considering the volume, weight and cost. To solve this problem, a multi-node motion estimation method based on the B-spline of the array POS is proposed to realize the motion compensation of remote-sensing loads without sub-IMUs. Firstly, the transfer alignment method based on fiber-grating multi-dimensional deformation measurement was adopted. Motion parameters of the remote-sensing payload equipped with sub-IMUs at different times can be obtained by observing and correcting the errors between the main POS and sub-IMUs. In this way, the space-time characteristics of each interpolation point are fully utilized. Additionally, the motion information of the main POS and all sub-IMUs is fitted through the estimation method based on the B-spline, during which wing deformation is considered to obtain the motion parameters of the remote-sensing payload equipped without a sub-IMU. In this way, the spatial correlation between the information of each node is fully utilized. Due to the full utilization of the spatiotemporal correlation of the motion information of each sub node, high-precision and highly reliable motion information of the remote-sensing loads not equipped with sub-IMUs is obtained. Furthermore, the proposed method can be modified locally without affecting other nodes, and has the advantages of a simple algorithm and easy engineering implementation. Finally, a semi-physical simulation based on ground-loading test was conducted. The results show that the baseline in the X-axis, Y-axis and Z-axis direction is improved by 0.484 mm, 0.137 mm and 1.225 mm, respectively, and that the measurement accuracy of roll angle is improved by 0.011°.

Characteristics analysis of resonance-based wireless power transfer using magnetic coupling and electric coupling

This study analyses the wireless power transfer of the resonance-based magnetic coupling method and resonance-based electric coupling method and provides information about the characteristics of each. To compare the characteristics of each method, the power transfer efficiency was analysed according to the transfer alignment and misalignment distance between the transceivers. More specifically, they were theoretically analysed through equivalent circuit models, and the results were verified through electromagnetic numerical analysis simulation and the fabrication and experimental results of a wireless power transfer coupler. Although both methods differ according to the coupling method, in terms of power transfer efficiency, it was found that they are determined by the same physical phenomena. Furthermore, in both methods, a null-power point occurred during misalignment between the transceivers. The misalignment distance within which the null-power point occurred is intrinsically determined by the structure of the resonant coupler.

가속도 정합 기반 전달 정렬을 통한 고정익 항공기의 유연성 오차 보상

본 논문에서는 고정익 항공기에서 발생하는 유연성 오차 보상을 위해 가속도 정합을 기반으로 한 전달 정렬 기법을 제시한다. 유연성은 주 관성항법장치와 종 관성항법장치의 상대적인 거리를 나타내는 레버암으로 인해 발생하며, 특히 항공기에서의 유연성은 선박에 비해 큰 진동수 파라미터를 가진다. 가속도 정합은 측정치 모델에서 레버암 및 유연성 오차가 반영되어 있어 유연성이 정확히 모델링된 경우 유연성으로 인한 오차의 보상 성능이 유리한 특성을 가진다. 본 논문에서는 유연성의 진동수 파라미터를 중심으로 속도, 자세, 가속도, 각속도 기법을 적용한 전달정렬 시뮬레이션을 수행하였다. 시뮬레이션 결과, 기존에 주로 사용되는 속도 자세 정합에 가속도 정합 기법을 적용함으로써 자세 오차의 수렴 속도와 추정 성능을 개선시킬 수 있었다. 반면 각속도 정합은 자세 정합을 대신하여 사용하여 연산량을 감수할 만큼 자세와 유연성 오차 추정에서 유리한 성능이 나타나지 않는 것을 확인하였다.