LGVINS:LiDAR-GPS-visual and inertial system based multi-sensor fusion for smooth and reliable UAV state estimation

With the development of Autonomous Unmanned Aerial Vehicle’s (UAV’s), Precise state estimation is a fundamental aspect of autonomous flight and plays a critical role in enabling robots specially in GPS denied environment to operate safely, reliably, and effectively across a wide range of applications and operational scenarios. In this paper, we propose a tightly-coupled multi-sensor filtering framework for robust UAV/UGV state estimation, which integrates data from an Inertial Measurement Unit (IMU), a stereo camera, GPS, and 3D range measurements from two Light Detection and Ranging (LiDAR) sensors. The proposed LGVINS system significantly improves the accuracy and robustness of state estimation in both structured and unstructured outdoor environments, such as bridge inspections, open fields, urban city and areas near buildings. It also improves positioning accuracy in scenarios with or without GPS signals. The goal is to exploit the fact that these sensor modalities have mutually exclusive strengths, the visual, inertial and the Lidar sensor techniques are implemented to compensate for the robots state estimate errors in multiple outdoor challenging environment. It effectively reduces long-term trajectory drift and ensures smooth, continuous state estimation, regardless of GPS satellite availability. We demonstrate and evaluate the LGVINS approach on public dataset as well as our own dataset collected from the proposed hardware integration on UAV, deployed on computationally-constrained systems. This demonstrates that the proposed system achieves higher accuracy and robustness in state estimation across various environments compared to currently available methods

How can collaboration impact writings in the L2 in a high-complexity school?

This study seeks to investigate the impact of collaboration on written productions in the L2 in a high-complexity school situated in the Maresme area (Barcelona). In order to carry out the research, qualitative data has been used to draw a comparison between sixteen individual writings and four collaborative texts performed by 2nd ESO students, with a low command of English, during a 2-hour class session. Consisting of three phases, this analysis focuses first on the texts from an error point of view; then it observes the students' conversations during the collaborative task through video recordings, and, finally, it provides an overview of their perception based on a questionnaire administered after the two tasks. Findings show a significant improvement in the overall results in regard to language production and a positive attitude from the students towards collaboration, which should be further explored by teachers working in challenging contexts.Aquest estudi té per objectiu investigar l'impacte de la col·laboració en produccions escrites en la L2 en un centre de màxima complexitat situat a la comarca del Maresme (Barcelona). Per dur a terme la recerca, s'han emprat dades de caràcter qualitatiu per tal de traçar una comparativa entre setze textos individuals i quatre de col·laboratius produïts per alumnes de 2n de la ESO, amb baix domini de l'anglès, durant una sessió de dues hores de classe. Consistent en tres fases, aquesta anàlisi es centra primer en els textos des del punt de vista dels errors; després observa les conversacions dels alumnes durant la tasca col·laborativa a través de gravacions de vídeo, i, finalment, proporciona una visió de les seves percepcions basada en un qüestionari realitzat després de les dues tasques. Els resultats mostren una millora considerable dels resultats globals pel que fa a la producció lingüística i una actitud positiva dels alumnes vers la col·laboració, que hauria de ser més explorada per aquells professors que treballen en contextos difícils

Cooperative robotic path planning for comprehensive bridge inspection with LiDAR technology:navigating unknown structures

This paper presents a new automated workflow designed for 3D reconstruction of previously unsurveyed bridges, developed within the EU-funded RAPID project. A cooperative approach, where Unmanned Aerial Vehicles (UAVs) and Un-manned Surface Vehicles (USVs) collaborate is employed to en-sure the safe execution of inspections in unknown environments. In this proposed approach, a survey is first performed using a UAV. The mapped environment serves to plan a path for a USV, addressing safety concerns associated with the UAV flight path. This collaboration enables a secure mapping of the underside features of the bridge. Real-world environment tests, conducted with one of the most popular commercial UAS platforms and a novel research USV, demonstrate the feasibility of the developed system in autonomous bridge inspections

Measurement of Carbon Dioxide Using Low-Cost & Compact Spectroscopy Based Gas Sensor

A compact and low-cost gas sensor using absorption spectroscopy for Carbon Dioxide (CO2) measurement is presented. The sensing principle is based on open-path direct absorption spectroscopy in the mid-infrared range. The improved reflective structure of optical gas sensor consists of low cost and compact components, such as filament emitter, multispectral pyroelectric detector, Calcium Fluoride (CaF2) window and aluminium curve reflective surface. In the previous investigation, the optimized gas cell structure was simulated using ZEMAX®12 software prior to fabrication for measuring CO2 gas concentration. The developed gas sensing system using the optimized gas cell structure has shown the capability of accurately detecting CO2 concentration. The sensor utilizes a CaF2 narrow bandpass (NBP) filter for detection of CO2 gas with no cross-sensitivity with other gases present in the gas cell. The repeatability of sensor’s response of detecting CO2 was tested with response times were calculated as being less than 1 second

A review of new and existing non-extractive techniques for monitoring marine protected areas

Publication history: Accepted - 23 June 2023; Published - 19 July 2023.Ocean biodiversity loss is being driven by several anthropogenic threats and significant efforts are required to halt losses and promote healthy marine ecosystems. The establishment of a network of Marine Protected Areas (MPAs) can help restrict damaging activities and have been recognised as a potential solution to aid marine conservation. When managed correctly they can deliver both ecological and socio-economic benefits. In recent times, MPA designations have increased rapidly while many countries have set future MPA targets for the decades ahead. An integral element of MPA management is adequate monitoring that collects data to assess if conservation objectives are being achieved. Data acquired by monitoring can vary widely as can the techniques employed to collect such data. Ideally, non-destructive and non-invasive methods are preferred to prevent damage to habitats and species, though this may rule out a number of traditional extractive sampling approaches such as dredges and trawls. Moreover, advances in ocean observation technologies enable the collection of large amounts of data at high resolutions, while automated data processing is beginning to make analyses more logistically feasible and less time-consuming. Therefore, developments to existing marine monitoring techniques and new emerging technologies have led to a diverse array of options when choosing to implement an MPA monitoring programme. Here, we present a review of new and existing non-extractive techniques which can be applied to MPA monitoring. We summarise their capabilities, applications, advantages, limitations and possible future developments. The review is intended to aid MPA managers and researchers in determining the suitability of available monitoring techniques based on data requirements and site conditions.This research was funded through the Marine Protected Area Monitoring and Management (MarPAMM) project, which is supported by the European Union’s INTERREG VA Programme, managed by the Special EU Programmes Body (SEUPB) with matching funding from the Government of Ireland, the Northern Ireland Executive, and the Scottish Government. This research was also carried out with the support of the Marine Institute under the Marine Research Programme with the support of the Irish Government

Highly Responsive CO2 Detection by an Improved & Compact Gas Sensor Using Mid-IR Spectroscopy

An improved and compact gas sensor using midinfrared spectroscopy for highly responsive Carbon Dioxide (CO2) detection is presented. The sensing principle is based on open-path direct absorption spectroscopy in the mid-infrared region. The improved reflective structure of optical gas sensor consists of low cost and compact components. Several gas cell configuration which includes SISO, 2-MISO, 4-MISO and 8- MISO were simulated using ZEMAX®12 using non-sequential ray tracing technique to get the optimum radius of the reflective curved surface. Sensitivity analysis has shown that the optimised structure of 4-MISO yields the highest sensitivity and power efficiency of -0.2895%-1 and 12.298% respectively. The developed gas sensing system using the optimised gas cell has shown the capability of accurately detecting CO2 concentration between 1.5% and 5.8% with no cross-sensitivity with other gases present in the gas cell. The newly developed CO2 sensor exhibits high responsivity with the recorded rise time and fall time of less than 1 second respectively

Dynamic positioning system for low-cost ROV

This paper examines the use of low-cost sensors and systems for automated underwater navigation and control. A low-cost dynamic positioning system is developed and utilised as critical component for remotely operated vehicle (ROV) tasks such as general visual inspection and photogrammetric survey. Unlike unmanned aerial vehicles (UAVs) that can rely on cost-effective and widely available GNSS sensors, this is not available to the subsea vehicle domain as these signals do not penetrate through water. In absence of GNSS capability, GPS-denied solutions such as dead-reckoning systems are required. This usually requires advanced motion and angle sensors with an array of aiding sensors. In this paper we use one of the world’s most affordable and high-performance ROVs, the BlueROV2, and with the integration of a waterlinked DVL we report on the development of a low-cost dynamic positioning system for BlueROV2. The paper showcases a low-cost solution for advanced function control subsea and demonstrates the capability and use of such ROVs in a wider range of underwater applications