20 research outputs found
Preliminary design, modeling and control of a fully actuated quadrotor UAV
In this paper a preliminary study on a new concept of fully actuated Unmanned Aerial Vehicle (UAV), named ODQuad (OmniDirectional Quadrotor), is presented. By exploiting two additional actuators, the designed UAV can simultaneously modify the tilting angle of all the propellers, in such a way to decouple position and attitude motions. This solution, differently from other fully actuated UAVs with tilted propellers, avoids internal forces and energy dissipation, due to non-parallel propellers’ axes. A preliminary mechanical design and the kinematic and dynamic models are developed. Moreover, a motion control scheme, based on a hierarchical two loop, has been designed. Simulations are provided in order to show the feasibility of the concept and the effectiveness of the control scheme
Vision-enhanced Peg-in-Hole for automotive body parts using semantic image segmentation and object detection
Artificial Intelligence (AI) is an enabling technology in the context of Industry 4.0. In particular, the automotive sector is among those who can benefit most of the use of AI in conjunction with advanced vision techniques. The scope of this work is to integrate deep learning algorithms in an industrial scenario involving a robotic Peg-in-Hole task. More in detail, we focus on a scenario where a human operator manually positions a carbon fiber automotive part in the workspace of a 7 Degrees of Freedom (DOF) manipulator. To cope with the uncertainty on the relative position between the robot and the workpiece, we adopt a three stage strategy. The first stage concerns the Three-Dimensional (3D) reconstruction of the workpiece using a registration algorithm based on the Iterative Closest Point (ICP) paradigm. Such a procedure is integrated with a semantic image segmentation neural network, which is in charge of removing the background of the scene to improve the registration. The adoption of such network allows to reduce the registration time of about 28.8%. In the second stage, the reconstructed surface is compared with a Computer Aided Design (CAD) model of the workpiece to locate the holes and their axes. In this stage, the adoption of a Convolutional Neural Network (CNN) allows to improve the holes’ position estimation of about 57.3%. The third stage concerns the insertion of the peg by implementing a search phase to handle the remaining estimation errors. Also in this case, the use of the CNN reduces the search phase duration of about 71.3%. Quantitative experiments, including a comparison with a previous approach without both the segmentation network and the CNN, have been conducted in a realistic scenario. The results show the effectiveness of the proposed approach and how the integration of AI techniques improves the success rate from 84.5% to 99.0%
MANAGEMENT OF VOLUNTARY SOYBEAN INFESTING WITH BEAN THE HERBICIDE ETHOXYSULFURON
A semeadura do feijoeiro após a colheita da soja pode ser um problema já que as plantasvoluntárias da cultura emergem após a colheita e competem com o feijão. O herbicidaethoxysulfuron tem sido usado para o manejo de diferentes espécies de plantas daninhas,dentre elas a soja voluntária infestante no cultivo do feijoeiro. Diante disso, esse estudo foidesenvolvido com o objetivo de avaliar a seletividade e a eficácia de diferentes doses deethoxysulfuron aplicado no feijoeiro para o controle de soja voluntária. O experimento foiinstalado em delineamento de blocos casualizados, com quatro repetições. Os tratamentostestados foram: 0, 12, 24, 36 e 48 g ha-1 de ingrediente ativo de ethoxysulfuron. Aos 10, 20e 30 dias após a aplicação dos tratamentos (DAT) foi avaliado, de modo visual, o controleda soja voluntária e a fitotoxicidade à cultivar de feijão IPR Tuiuiú. Na colheita do feijãodeterminou-se a massa de mil grãos (g) e a produtividade de grãos (kg ha-1). O incrementodas doses de ethoxysulfuron contribuiu para o aumento da eficácia de controle da sojavoluntária infestante do feijoeiro. As maiores fitotoxicidades ao feijoeiro cultivar IPRTuiuiú foram ocasionadas pelo uso das maiores doses do ethoxysulfuron. A dose de25,8 g ha-1 de ethoxysulfuron ocasionou a maior produtividade de grãos da cultivar de feijãoIPR Tuiuiú, com controle de 98,9% da soja voluntária e fitotoxicidade em torno de 21%.he sowing of beans after soybean harvest can be a problem since the voluntary plants ofthe crop emerge after harvesting and compete with beans. The herbicide ethoxysulfuron hasbeen used for the management of different species of weeds, among them the voluntaryweed soybean in the cultivation of beans. Therefore, this study was developed with theobjective of evaluating the selectivity and effectiveness of different doses of ethoxysulfuronapplied to common bean for the control of voluntary soybeans. The experiment wasinstalled in a randomized block design, with four replications. The tested treatments were:0, 12, 24, 36 and 48 g ha-1 of active ingredient of ethoxysulfuron. At 10, 20 and 30 daysafter application of the treatments (DAT), the control of voluntary soybean andphytotoxicity to the IPR Tuiuiú bean cultivar were visually evaluated. In the bean harvest,the mass of a thousand grains (g) and grain yield (kg ha-1) were determined. The increase inethoxysulfuron doses contributed to the increase in the control efficiency of voluntarysoybean infesting beans. The highest phytotoxicities to common bean cultivar IPR Tuiuiúwere caused by the use of the highest doses of ethoxysulfuron. The dose of 25.8 g ha-1 ofethoxysulfuron caused the highest grain yield of the bean cultivar IPR Tuiuiú, with controlof 98.9% of the voluntary soybean and phytotoxicity around 21%
Control of an Omnidirectional UAV for Transportation and Manipulation Tasks
This paper presents a motion control scheme for a new concept of
omnidirectional aerial vehicle for transportation and manipulation
tasks. The considered aerial platform is a novel quadrotor with the
capability of providing multi-directional thrust by adding an actuated
gimbal mechanism in charge of modifying the orientation of the frame on
which the four rotors are mounted. The above mechanical design,
differently from other omnidirectional unmanned aerial vehicles (UAVs)
with tilted propellers, avoids internal forces and energy dissipation
due to non-parallel propellers' axes. The proposed motion controller is
based on a hierarchical two-loop scheme. The external loop computes the
force to be applied to the vehicle and the reference values for the
additional joints, while the inner loop computes the joint torques and
the moment to be applied to the multirotor. In order to make the system
robust with respect to the external loads, a compensation of contact
forces is introduced by exploiting the estimate provided by a momentum
based observer. The stability of the motion control scheme is proven via
Lyapunov arguments. Finally, two simulation case studies prove the
capability of the omnidirectional UAV platform to track a 6-DoFs
trajectory both in free motion and during a task involving grasping and
transportation of an unknown object
The ODQuad: Design and Experimental Validation of a Novel Fully-actuated Quadrotor
This work experimentally validates a novel fully-actuated quadrotor-based unmanned aerial vehicle named ODQuad (OmniDirectional Quadrotor). The ODQuad is composed of three main parts arranged in a gimbal configuration. The internal mechanism is composed of two rotational joints with orthogonal and incident axes which allow to decouple the horizontal motions from the vehicle body rolling and pitching. Firstly, the physical prototype is presented and the motion controller, inherited by [1], has been tailored in such a way to integrate the servo actuators of the internal gimbal mechanism. Three trajectories have been commanded to prove the decoupling between the position and attitude motion. The results confirm the effectiveness of the proposed multirotor design
High-Definition 3D Exoscope-Assisted Barbed Pharyngoplasty for OSAS and Snoring: Better Than Live
Recently, a high-definition 3D exoscope (VITOM), a new magnification system that provides a 3D image of the surgical field, has been introduced. This study aims to describe the first use of VITOM 3D technology in Barbed Pharyngoplasty (BP) for Obstructive Sleep Apnea (OSA). VITOM 3D technology is used to support visualization during BP in a male patient affected by severe OSA with a circular palatal collapse pattern at drug-induced sleep endoscopy. During the surgical procedure, this approach markedly improves the visualization of the surgical field through anatomic details of the oral cavity, facilitating surgical dissection and enhancing the teaching environment. It allows for a better involvement and more interactions during the surgery, as scrubbed and assistant nurses can see the surgical field and anticipate the surgeon’s choice of instrument. VITOM 3D technology, by combining a telescope with a standard endoscope, has been successfully used in various surgical disciplines and could be very useful, especially in teaching hospitals. VITOM 3D can guarantee “a real immersive” surgical experience for all participants in the operating room. Economic and efficacy studies would be conducted to support the use of a VITOM-3D exoscope in common clinical practice
Vision based robot-to-robot object handover
This work deals with an autonomous robot-to-robot
object handover in the presence of uncertainties. Both the giver
and receiver robots are equipped with an hand-in-eye depth
camera and a deep learning based approach is adopted for
detecting the presence of the object. The physical exchange is
performed by recurring to an estimate of the contact forces and
an impedance control, which allows the receiver robot to perceive
the presence of the object and the giver one to recognize that
the handover is complete
Could the use of a new novel bipolar radiofrequency device (Aerin) improve nasal valve collapse? A systematic review and meta-analysis
Abstract Background Surgical treatment for nasal obstruction caused by nasal valve collapse requires a significant recovery period and risks of complications, while nasal dilators are uncomfortable. Recently, radiofrequency treatment of lateral walls has been used under local anesthesia as an office base surgery. This work aims to assess the efficacy of a new radiofrequency device, the Vivaer™ System (Aerin Medical, Sunnyvale, CA), to treat nasal obstruction through a systematic review and meta-analysis. Methods Two researchers independently reviewed the literature up to December 2021. Studies on patients seeking treatment for nasal obstruction due to nasal valve collapse were included in the analysis. Results Four studies (218 patients) met the inclusion criteria and treated the nasal valve regions bilaterally with the Aerin Medical Vivaer™ System. After the treatment, the NOSE score was reduced at three months postoperatively. Minor adverse events were reported in the included studies, and two showed no complications. None of the studies reported changes in the external appearance of the nose. Conclusion The radiofrequency treatment using the Vivaer device can be useful for treating nasal valve collapse, improving significantly subjective breathing symptom scores. Further studies on a large scale are needed to confirm these results
Endolymphatic duct and sac decompression: A new technique for Ménière’s disease treatment
BACKGROUND: The present article aims to introduce the endolymphatic duct and sac decompression technique (DASD) and to give a spotlight on its benefits in Ménière’s disease (MD) treatment. METHODS: Eighty-two patients with intractable MD which met the inclusion criteria were recruited and underwent DASD. This technique allows a meningeal decompression of the duct and the sac from the posterior cranial fossa to the labyrinthine block. The authors considered as main outcomes, the change of the dizziness handicap inventory (DHI) results, with the evaluations of the three sub-scales (Functional scale, Physical scale, and Emotional scale); ear fullness and tinnitus change on the perceptions of the patient; and hearing stage with four-Pure Tone Average (500 hz-1000 hz-2000 hz-4000 hz). The differences between the preoperative and the postoperative score were evaluated. A comparison with the literature was conducted. RESULTS: After a 14-month follow-up, patients that underwent DASD reported a remarkable improvement of the symptoms in all three functional scales, confirmed by the total DHI. The difference between preoperative and postoperative scores is statistically significant. The data describe an ear fullness and tinnitus improvement. The multi-frequency tonal average before and after the surgery does not suggest a worsening of the value for any of 82 patients. CONCLUSION: The modification of sac surgery includes the endolymphatic duct in the decompression area allowing inner ear functional improvement, vertigo control, ear fullness improvement with minimal risk of facial nerve paralysis, and hearing loss. DASD is an improved old surgical technique
Odontogenic Sinusitis from Classical Complications and Its Treatment: Our Experience
Odontogenic sinusitis (ODS) refers to the maxillary sinus infection, which is secondary to either adjacent infectious dental pathologies or procedures. The aim of this retrospective study is to report the experiences of the department of integrated therapies in otolaryngology (Campus Bio-Medico Foundation, Rome, Italy) in classifying and treating patients that are affected by odontogenic sinusitis derived from “classic complications”. A total of 68 patients responding to the criteria and to the definition as a classical odontogenic complication were included. The surgical therapy consisted of a combined oral and nasal simultaneous approach for 28 patients (43%), a combined non-simultaneous approach for 4 patients (6%), a nasal only approach for 14 patients (21%), and an oral only approach for 20 patients (30%). All the patients presented a complete resolution of the symptoms. The choice of performing a nasal, oral, or combined approach is based on the presence of anatomical elements that facilitate sinusitis and reinfection occurrence, such as deviated nasal septum, concha bullosa, or obstructed osteo-meatal complex. The correct use of validated classification, the pre-operative CT scan, a multidisciplinary approach, and an appropriate presurgical examination are the necessary elements to obtain a good success rate