scholarly journals Rotation Active Sensors Based on Ultrafast Fibre Lasers

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3530
Author(s):  
Igor Kudelin ◽  
Srikanth Sugavanam ◽  
Maria Chernysheva

Gyroscopes merit an undeniable role in inertial navigation systems, geodesy and seismology. By employing the optical Sagnac effect, ring laser gyroscopes provide exceptionally accurate measurements of even ultraslow angular velocity with a resolution up to 10−11 rad/s. With the recent advancement of ultrafast fibre lasers and, particularly, enabling effective bidirectional generation, their applications have been expanded to the areas of dual-comb spectroscopy and gyroscopy. Exceptional compactness, maintenance-free operation and rather low cost make ultrafast fibre lasers attractive for sensing applications. Remarkably, laser gyroscope operation in the ultrashort pulse generation regime presents a promising approach for eliminating sensing limitations caused by the synchronisation of counter-propagating channels, the most critical of which is frequency lock-in. In this work, we overview the fundamentals of gyroscopic sensing and ultrafast fibre lasers to bridge the gap between tools development and their real-world applications. This article provides a historical outline, highlights the most recent advancements and discusses perspectives for the expanding field of ultrafast fibre laser gyroscopes. We acknowledge the bottlenecks and deficiencies of the presented ultrafast laser gyroscope concepts due to intrinsic physical effects or currently available measurement methodology. Finally, the current work outlines solutions for further ultrafast laser technology development to translate to future commercial gyroscopes.

Author(s):  
Paweł Burdziakowski

Low-cost solutions for autonomous aerial platforms are being intensively developed and used within geodetic community. Unmanned aerial vehicles are becoming very popular and widely used for photogrammetry and remote sensing applications. Today’s market offers an affordable price components for unmanned solution with significant quality and accuracy growth. Every year market offers a new solutions for autonomous platforms with better technical specifications. Commercial drones for amateurs are widely offered and presents a quality and accuracy not available in past few years. In this paper an autonomous open source low cost haxacopter system for photogrammetry and intelligent navigation technologies evaluation is being presented. The system was designed and assembled for technologies testing and for educational purposes. The drone is based only on open source hardware and software. All components are based on open source and commercial of the shelf products. That approach to the drones construction provides a many capabilities to test, implement and execute new algorithms, solutions and tasks. Providing basic configuration tools system enables students to safely perform elementary setup and testing. An advanced configurations system tool and open source structure enables to execute advanced scientific test and research. Paper presents results of designed process, system configuration and specification, technical issues that was being solved during test flights and practical research results.


2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.


Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4910
Author(s):  
Xiaoqiao Yuan ◽  
Jie Li ◽  
Xi Zhang ◽  
Kaiqiang Feng ◽  
Xiaokai Wei ◽  
...  

Rotation modulation (RM) has been widely used in navigation systems to significantly improve the navigation accuracy of inertial navigation systems (INSs). However, the traditional single-axis rotation modulation cannot achieve the modulation of all the constant errors in the three directions; thus, it is not suitable for application in highly dynamic environments due to requirements for high precision in missiles. Aiming at the problems of error accumulation and divergence in the direction of rotation axis existing in the traditional single-axis rotation modulation, a novel rotation scheme is proposed. Firstly, the error propagation principle of the new rotation modulation scheme is analyzed. Secondly, the condition of realizing the error modulation with constant error is discussed. Finally, the original rotation modulation navigation algorithm is optimized for the new rotation modulation scheme. The experiment and simulation results show that the new rotation scheme can effectively modulate the error divergence of roll angle and improve the accuracy of roll angle by two orders of magnitude.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Marceline F. Finda ◽  
Fredros O. Okumu ◽  
Elihaika Minja ◽  
Rukiyah Njalambaha ◽  
Winfrida Mponzi ◽  
...  

Abstract Background Different forms of mosquito modifications are being considered as potential high-impact and low-cost tools for future malaria control in Africa. Although still under evaluation, the eventual success of these technologies will require high-level public acceptance. Understanding prevailing community perceptions of mosquito modification is, therefore, crucial for effective design and implementation of these interventions. This study investigated community perceptions regarding genetically-modified mosquitoes (GMMs) and their potential for malaria control in Tanzanian villages where no research or campaign for such technologies has yet been undertaken. Methods A mixed-methods design was used, involving: (i) focus group discussions (FGD) with community leaders to get insights on how they frame and would respond to GMMs, and (ii) structured questionnaires administered to 490 community members to assess awareness, perceptions and support for GMMs for malaria control. Descriptive statistics were used to summarize the findings and thematic content analysis was used to identify key concepts and interpret the findings. Results Nearly all survey respondents were unaware of mosquito modification technologies for malaria control (94.3%), and reported no knowledge of their specific characteristics (97.3%). However, community leaders participating in FGDs offered a set of distinctive interpretive frames to conceptualize interventions relying on GMMs for malaria control. The participants commonly referenced their experiences of cross-breeding for selecting preferred traits in domestic plants and animals. Preferred GMMs attributes included the expected reductions in insecticide use and human labour. Population suppression approaches, requiring as few releases as possible, were favoured. Common concerns included whether the GMMs would look or behave differently than wild mosquitoes, and how the technology would be integrated into current malaria control policies. The participants emphasised the importance and the challenge of educating and engaging communities during the technology development. Conclusions Understanding how communities perceive and interpret novel technologies is crucial to the design and effective implementation of new vector control programmes. This study offers vital clues on how communities with no prior experience of modified mosquitoes might conceptualize or respond to such technologies when deployed in the context of malaria control programmes. Drawing upon existing interpretive frames and locally-resonant analogies when deploying such technologies may provide a basis for more durable public support in the future.


Chemosensors ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 108
Author(s):  
Giancarla Alberti ◽  
Camilla Zanoni ◽  
Vittorio Losi ◽  
Lisa Rita Magnaghi ◽  
Raffaela Biesuz

This review illustrates various types of polymer and nanocomposite polymeric based sensors used in a wide variety of devices. Moreover, it provides an overview of the trends and challenges in sensor research. As fundamental components of new devices, polymers play an important role in sensing applications. Indeed, polymers offer many advantages for sensor technologies: their manufacturing methods are pretty simple, they are relatively low-cost materials, and they can be functionalized and placed on different substrates. Polymers can participate in sensing mechanisms or act as supports for the sensing units. Another good quality of polymer-based materials is that their chemical structure can be modified to enhance their reactivity, biocompatibility, resistance to degradation, and flexibility.


Author(s):  
William R. Wilson ◽  
Laura L. Jones ◽  
Mason A. Peck

In the past several years, small satellites have taken on an increasingly important role as affordable technology demonstrators and are now being viewed as viable low-cost platforms for traditional spacecraft mission objectives. As such, the CubeSat standard (1 kg in a 10 cm cube) has been widely adopted for university-led development efforts even as it is embraced by traditional spacecraft developers, such as NASA. As CubeSats begin to take on roles traditionally filled by much larger spacecraft, the infrastructure for dynamics and controls testing must also transition to accommodate the different size and cost scaling associated with CubeSats. While air-bearing-based testbeds are commonly used to enable a variety of traditional ground testing and development for spacecraft, few existing designs are suitable for development of CubeSat-scale technologies, particularly involving multibody dynamics. This work describes Cornell University's FloatCube testbed, which provides a planar reduced-friction environment for multibody dynamics and controls technology development for spacecraft less than 6 kg and a 15 cm cube. The multimodule testbed consists of four free-floating air-bearing platforms with on-board gas supplies that allow the platforms to float over a glass surface without external attachments. Each of these platforms, or FloatCubes, can host CubeSat-sized payloads at widely ranging levels of development, from prototype components to full-scale systems. The FloatCube testbed has already hosted several successful experiments, proving its ability to provide an affordable reduced-friction environment to CubeSat-scale projects. This paper provides information on the system design, cost, performance, operating procedures, and applications of this unique, and increasingly relevant, testbed.


1984 ◽  
Vol 106 (4) ◽  
pp. 287-291
Author(s):  
H. F. Brose

Renewed interest and planning for a Space Station, probably NASA’s next major space activity, poses a new challenge for ETCLS technology not previously emphasized. Over the past two decades, regenerative life support technology development for Space Station has been underway. This development effort was always aimed at regenerative (closed loop) life support for a full capability Space Station. The level of priority for manned space presence and current budgetary pressures dictate the need for a low cost profile program with an evolutionary growth Space Station. The initial capability may be a small station with a crew of 2 or 3. This station could grow in size and capability by the addition of modules to a station with a crew of 8 to 12 with the possibility of multiple stations in orbit. Depending upon the selected missions, the early station may be best served by an open or only partially closed loop ETCLS whereas the final station may need a completely closed loop ETCLS. The challenge would be to grow in-orbit the ETCLS system capability in a “no-throw-away” fashion in order to minimize annual and total program cost. This paper discusses a possible ETCLS system evolutionary growth scenario, the Space Station architecture variations influencing the ETCLS system design, and a technology preparedness plan for Space Station ETCLS.


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