1,354,773 research outputs found
Motion detection technology as a tool for cardiopulmonary resuscitation (CPR) quality improvement
No full textThe most popular method of training in basic life support and AED remains instructor-led training courses. Recent reviews provide good evidence to support alternative methods of training including lay instructors, self-directed learning (web, video, poster) and CPR feedback/prompt devices
A Compliant and Robust Robotic Hand Fabricated with 3D Printed Soft Materials
No full textThis work presents design and prototype of CORA hand (COmpliant Robotic hAnd) a novel robotic hand conceived for compliance and robustness in grasping tasks, and for easy manufacturing and maintenance. It takes advantage of novel soft-polymer printable filaments to obtain intrinsic compliance during grasping and accidental contacts. All manufactured parts are designed and optimized for conventional 3D printers, and additional implemented components are selected among standardized, off-the-shelf mechanical parts. Design of the hand considers easy accessibility of components to simplify maintenance and replacements. In this paper design of the hand is presented, focusing on specific solutions adopted for improving robustness of the final 3D printed parts and for obtaining compliance during interaction with the environment. Design of the soft-polymer links has been evaluated with FEM simulation. A preliminary prototype of the robotic hand was built and evaluated in basic grasping poses of different objects
Special Issue of Virtual Reality Journal on Multisensory Interaction in Virtual Environments
No full textLinear-Quadratic-Gaussian Torque Control: Application to a Flexible Joint of a Rehabilitation Exoskeleton
No full textA Detection Method of Faults in Railway Pantographs Based on Dynamic Phase Plots
No full textSystems for detection of damages in railway pantographs effectively reduce the cost of maintenance and improve time scheduling. In this paper, we present an approach to design a monitoring tool fitting strong customer requirements such as portability and ease of use. Pantograph has been modeled to estimate its dynamical properties, since no data are available. With the aim to focus on suspensions health, a two Degrees of Freedom (DOF) scheme has been adopted. Parameters have been calculated by means of analytical dynamics. A Finite Element Method (FEM) modal analysis verified the former model with an acceptable error. The detection strategy seeks phase-plots topology alteration, induced by defects. In order to test the suitability of the method, leakage in the dashpot was simulated on the lumped model. Results are interesting because changes in phase plots are more appreciable than frequency-shift. Further calculations as well as experimental tests will support future developments of this smart strategy
ColabNAS: Obtaining lightweight task-specific convolutional neural networks following Occam's razor
No full textThe current trend of applying transfer learning from convolutional neural networks (CNNs) trained on large datasets can be an overkill when the target application is a custom and delimited problem, with enough data to train a network from scratch. On the other hand, the training of custom and lighter CNNs requires expertise, in the from-scratch case, and or high-end resources, as in the case of hardware-aware neural architecture search (HW NAS), limiting access to the technology by non-habitual NN developers. For this reason, we present ColabNAS, an affordable HW NAS technique for producing lightweight task-specific CNNs. Its novel derivative-free search strategy, inspired by Occam's razor, allows to obtain state-of-the-art results on the Visual Wake Word dataset, a standard TinyML benchmark, in just 3.1 GPU hours using free online GPU services such as Google Colaboratory and Kaggle Kernel
An optimization procedure based on kinematics analysis for the design parameters of a 4-UPU parallel manipulator
No full textThe paper presents the kinematics analysis of a 4-UPU fully parallel manipulator and a numerical procedure for its optimization. The 4-UPU kinematics is featured by four UPU legs, moreover the prismatic joint of each leg is supposed to be actuated. The end-effector has 4 degrees of freedom (Dofs), the three translations and the rotation along the direction perpendicular to the base platform. Singularity configurations have been analytically determined and the analysis of both actuation and constraint Jacobian by screw theory has been performed. Finally, a numerical procedure for the optimization of the design parameters of the manipulator is presented. The optimization procedure has been carried out using adimensional parameters in order to generalize the obtained results. The presented optimization procedure allows to define the ratios between the geometrical features of the manipulator which maximize a generic performance parameter in a designed workspace by avoiding all the possible singularity conditions. The obtained results are useful for the design of all the manipulators based on the 4-UPU kinematics. In particular, the case study of the design of a wearable fingertip haptic device is presented and discussed
Experimental identification of faults in a railway pantograph mechanism in presence of nonlinear damping (Aimeta 2017)
No full textPredictability may transform maintenance from a cost centre into a profit unit. Industries are indeed investing in innovative technologies to implement the purpose. In this paper we introduce a project meant to develop a robotic tool for the assessment of railway pantographs through a vibration based detection of faults. Nonlinearities such as intense dependence of damping on speed and non-negligible friction in joints make the applicaton particularly challenging. These phenomena could in fact drastically modify the behavior with respect to simpler linear models predictions. Experimental frequency response functions (FRFs) were hence derived for several input amplitudes so as to estimate at which extent modal parameters are related to the energy level. To discriminate the sources of nonlinearity FRFs were carried out even after the damper had been removed. Phase plots shape alteration was then observed for a couple of frequencies and as many amplitudes to delve deeper into dynamics changes. A first indication on the suitability of FRFs to detect faults is pursued considering the absence of the dashpot as an example of defect, i.e. a severe leakage, comparing modal information from the two data sets
Human Recognition for Resource-Constrained Mobile Robot Applied to Covid-19 Disinfection
No full textThe global COVID-19 pandemic has stimulated the use of disinfection robots: in September 2021, following a European Commission’s action, 200 disinfection robots were delivered to European Hospitals. UV-C light is a common disinfection method, however, direct exposure to UV-C radiation is harmful and disinfection can be operated only in areas strictly forbidden to human personnel. We believe more advanced safety mechanisms are needed to increase the operational flexibility and safety level. We propose a safety mechanism based on vision and artificial intelligence, optimised for execution on mobile robot platforms. It analyses in real-time four video streaming and disables UV-C lamps when needed. Concerning other detection methods, it has a relatively wider and deeper range, and the capability to operate in a dynamic environment. We present the development of the method with a performance comparison of different implementation solutions, and an on-field evaluation through integration on a mobile disinfection robot
A Miniature Direct-Drive Hydraulic Actuator for Wearable Haptic Devices based on Ferrofluid Magnetohydrodynamic Levitation
No full textHydraulic and pneumatic actuators in haptics offer the advantage of soft and compliant interfaces, with the drawback of cumbersome driving devices and limited modulation capabilities. We propose a miniature hydraulic actuator based on a linear electromagnetic motor with an embedded ferrofluid sealing. The solution has two main advantages: it shows no static friction due to the magnetohydrodynamic levitation effect of the ferrofluid, and the output force can be scaled (by varying the radius of the actuator) without introducing noise and friction of mechanical reduction mechanisms. Moreover, soft and compliant interfaces in the form of actuated pouches can be obtained on wearable devices with embedded actuators. As a concept prototype, we present here a compact and soft haptic thimble integrating the proposed actuator: experimental characterization at the bench, and perception experiments with the final prototype, evaluate the low-noise rendering capability of the method
- …
