1,721,310 research outputs found
Occupancy grid mapping for rover navigation based on semantic segmentation
Full text linkObstacle mapping is a fundamental building block of the autonomous navigation pipeline of many robotic platforms such as planetary rovers. Nowadays, occupancy grid mapping is a widely used tool for obstacle perception. It foreseen the representation of the environment in evenly spaced cells, whose posterior probability of being occupied is updated based on range sensors measurement. In more classic approaches, the cells are updated to occupied at the point where the ray emitted by the range sensor encounters an obstacle, such as a wall. The main limitation of this kind of methods is that they are not able to identify planar obstacles, such as slippery, sandy, or rocky soils. In this work, we use the measurements of a stereo camera combined with a pixel labeling technique based on Convolution Neural Networks to identify the presence of rocky obstacles in planetary environment. Once identified, the obstacles are converted into a scan-like model. The estimation of the relative pose between successive frames is carried out using ORB-SLAM algorithm. The final step consists of updating the occupancy grid map using the Bayes' update Rule. To evaluate the metrological performances of the proposed method images from the Martian analogous dataset, the ESA Katwijk Beach Planetary Rover Dataset have been used. The evaluation has been performed by comparing the generated occupancy map with a manually segmented ortomosaic map, obtained by drones' survey of the area used as reference
Towards the development of a cyber-physical measurement system (CPMS): Case study of a bioinspired soft growing robot for remote measurement and monitoring applications
Full text linkThe most effective expression of the 4.0 Era is represented by cyber-physical systems (CPSs). Historically, measurement and monitoring systems (MMSs) have been an essential part of CPSs; however, by introducing the 4.0 enabling technologies into MMSs, a MMS can evolve into a cyber-physical measurement system (CPMS). Starting from this consideration, this work reports a preliminary case study of a CPMS, namely an innovative bioinspired robotic platform that can be used for measurement and monitoring applications in confined and constrained environments. The innovative system is a "soft growing" robot that can access a remote site through controlled lengthening and steering of its body via a pneumatic actuation mechanism. The system can be endowed with different sensors at the tip, or along its body, to enable remote measurement and monitoring tasks; as a result, the robot can be employed to effectively deploy sensors in remote locations. In this work, a digital twin of the system is developed for simulation of a practical measurement scenario. The ultimate goal is to achieve a self-adapting, fully/partially autonomous system for remote monitoring operations to be used reliably and safely for the inspection of unknown and/or constrained environments
High resolution servomotor for space application
No full textIn this paper a custom-built Servo-Motor for space application is presented and discussed. This
device was designed for the OSIRIS instrument of the ESA Rosetta spacecraft, scheduled to
fly on 2004. The necessity to limit both mass and dimension of the Servo-Motor suggested to
design a custom-built system, made up of a “Limited Angle Torque” motor and a high
resolution optical encoder. The high ratio between the resolution and the outer diameter of the
motor and the particular compactness of the system make the developed Servo-Motor of great
interest for its use in space missions and for future industrial production
Optical performance evaluation of the high spatial resolution imaging camera of BepiColombo space mission
No full textThermo-elastic analyses of the High spatial Resolution Imaging Camera (HRIC), which is mounted on Mercury Planetary Orbiter BepiColombo Integrated Observatory SYStem suit (SIMBIO-SYS) of BepiColombo space mission, are carried out in order to evaluate the effect of thermo-elastic deformations on the optical performance experienced by the camera at the worst thermal scenario of Mercury space environment. In particular, the optical performance is evaluated in terms of the pointing error of the camera and the potential presence of optical aberrations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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