Dynamic modelling of a 3-CPU parallel robot via screw theory

The article describes the dynamic modelling of I.Ca.Ro., a novel Cartesian parallel robot recently designed and prototyped by the robotics research group of the Polytechnic University of Marche. By means of screw theory and virtual work principle, a computationally efficient model has been built, with the final aim of realising advanced model based controllers. Then a dynamic analysis has been performed in order to point out possible model simplifications that could lead to a more efficient run time implementation

Dynamic modelling of a 3-CPU parallel robot via screw theory

Abstract. The article describes the dynamic modelling of I.Ca.Ro., a novel Cartesian parallel robot recently designed and prototyped by the robotics research group of the Polytechnic University of Marche. By means of screw theory and virtual work principle, a computationally efficient model has been built, with the final aim of realising advanced model based controllers. Then a dynamic analysis has been performed in order to point out possible model simplifications that could lead to a more efficient run time implementation

Tools and Methods for Human Robot Collaboration: Case Studies at i-LABS

The collaboration among humans and machines is one of the most relevant topics in the Industry 4.0 paradigm. Collaborative robotics owes part of the enormous impact it has had in small and medium size enterprises to its innate vocation for close cooperation between human operators and robots. The i-Labs laboratory, which is introduced in this paper, developed some case studies in this sense involving different technologies at different abstraction levels to analyse the feasibility of human-robot interaction in common, yet challenging, application scenarios. The ergonomics of the processes, safety of operators, as well as effectiveness of the cooperation are some of the aspects under investigation with the main objective of drawing to these issues the attention from industries who could benefit from them

Bioplastica autoprodotta a base di bucce di banana per produzione di oggetti di bigiotteria femminile

Il presente lavoro propone una possibile utilizzazione di uno scarto diffusissimo in ambito agro-alimentare, le bucce delle banane, per la fabbricazione di un biocomposito adatto alla produzione di piccoli oggetti di design, in particolare di una collezione di bigiotteria. Il materiale, denominato "Banpur", è sviluppato attraverso tentativi sperimentali, accoppiando lo scarto in modo il più possibile leggero e naturale, oltre che aromatizzandolo. La sperimentazione s'inserisce nella recente tendenza all'autoproduzione dei materiali, rivalorizzando gli scarti in un nuovo concetto di sostenibilità, basato su una maggiore durata temporale, coniugata con un maggior valore intrinseco ed un legame tra il possessore e l'oggetto, ed offrendo una fruibilità del materiale che vada oltre la funzionalità e l'interazione tattile

Practical range of applicability of a linear stiffness model of an elliptical flexure hinge

This paper presents the analysis of a linear stiffness model of an elliptical flexure hinge. The purpose of the study is to support the mechanical designer in choosing the geometric dimensions of the hinge based on design specifications, driven by the accuracy that can later be achieved in planning its motion using the related stiffness model. Results are presented as a comparison between the analytical model and a finite element model of the flexure hinge, showing the practical range of applicability of the analytical model and its limitations. A case study show how to design a flexure hinge of small size for micro scale robotic or mechatronic operations

A collision avoidance strategy for redundant manipulators in dynamically variable environments: On-line perturbations of off-line generated trajectories

In this work, a comprehensive control strategy for obstacle avoidance in redundant manipulation is presented, consisting of a combination of off-line path planning algorithms with on-line motion control. Path planning allows the avoidance of fixed obstacles detected before the start of the robot’s motion; it is based on the potential fields method combined with a smoothing process realized by means of interpolation with Bezier curves. The on-line motion control is designed to compensate for the motion of the obstacles and to avoid collisions along the kinematic chain of the manipulator; it is realized by means of a velocity control law based on the null space method for redundancy control. A new term is introduced in the control law to take into account the speed of the obstacles as well as their position. Simulations on a simplified planar case are presented to assess the validity of the algorithms and to estimate the computational effort in order to verify the transferability of our approach to a real system

Dynamic Analysis of a Utility Car Driven by “In-Wheel” Engines

The paper describes the studies that have been developed at the Università Politecnica delle Marche in order to identify the vertical dynamics of a research prototype of a utility car. The vehicle is driven by two “in wheel” engines that are arranged in the rear axle: such kind of innovative actuation is characterized by obvious benefits, especially in the drive-by-wire context, but the introduction of heavy unsuspended masses needs a deep investigation of vehicle dynamics. Therefore a complex multibody analysis has been undertaken in order to assess both the resulting dynamic behaviour of the chassis, that affects passengers’ comfort and vehicle stability, and the level of vibrations induced on motors’ parts, e.g. the permanent magnets that are glued onto the spinning rotor

Active Paintings. Design Project for a Portable Exhibition for People with Dementia or Cognitive Impairment

Portable exhibition composed by six stations, each of which represents a different painting, associated with amanual or cognitive activity designed for elderly people with dementia or cognitive impairment and their caregiver. Art was found to be an excellent therapy for various disorders, it helps to connect with one’s own creativity and inner self, to express our self in a non-verbal way, but equally (or more) effectively. For some categories of people unfortunately it is not easily accessible: this is the case of elderly people, in particular the ones with dementia or cognitive impairment. The project’s purpose is to bring art directly into retirement homes, to a group of people that usually has not the possibility to enjoy it and that, instead, would benefit a lot. This is possible also due to the development of specific activities, connected to every painting, that aim to exploit the residual abilities of the elderly with dementia and/or cognitive decay, to improve their general state of well-being

Collaborative Robotics for Rehabilitation: A Multibody Model for Kinematic and Dynamic Analysis

Human-Robot Collaboration is increasing in industrial settings because of the robot’s accuracy and repeatability join perfectly with human’s problem solving to enhance the industrial productivity. Collaborative robots share the workspace with operators in order to reduce human workload and guarantee performances. The reliability and safety of these robots allow their application in the health care sector (e.g. neuromuscular rehabilitation). The cobot-assisted therapy is becoming a significant supplement to the traditional one aimed at providing intensive and repetitive rehabilitating tasks to improve the patient’s recovery. The human-robot system presented in this paper is a closed kinematic chain composed of a robotic arm attached to the human forearm through a custom handle system. The handle, designed with simple components, is used for primary rehabilitation exercises. The kinematic models of human and robotic arms presented in this study are applied to develop trajectory planning algorithm in the joint space. Robot joints torques needed for guiding the patient limb are obtained by multibody dynamic simulations, assessing the capability of the manipulator to perform the task at given speeds and loads. The tools and methods proposed in this work allow for a preliminary study on cobot-assisted-therapy by different human-cobot-working modalities

A Framework for the Study of Human-Robot Collaboration in Rehabilitation Practices

Collaborative robots and humans can cooperate in different industrial processes by combining their peculiar skills: the accuracy and repeatability of the manipulators can be exploited in synergy with human intelligence and flexibility. Since the cobots are safe and reliable, they can be adopted in the health sector, in particular in rehabilitation: the cobots allow the three-dimensional manipulation of the limbs and can be easily adapted to different anthropometric parameters. The kinematic models of the human-robot system presented in this paper can be exploited to develop motion planning algorithms for rehabilitation exercises. Furthermore, the estimation of the interaction forces in the human-robot interface can be obtained by multibody dynamic simulations. The proposed methodology is a starting point for the study of the integration of cobots into current rehabilitation practices, evaluating the feasibility and providing useful ideas in order to plan different man-robot working modalities