Search results for "MEC"
showing 10 items of 15890 documents
Engineering insights from an anthropocentric cyber-physical system: A case study for an assembly station
2016
Abstract To effectively cope with the complexity of manufacturing control problems the cyber-physical systems are engineered to work in the social space. Therefore the research in the field of cyber-physical systems needs to address social aspects when this concept is adopted in factory automation. The paper argues for an anthropocentric cyber-physical reference model as the basic decomposition unit for the design of distributed manufacturing control systems. The model assimilates all the required components (i.e. physical, computational and human) of a synthetic hybrid system in an integrated way. This is due to the real need to design cyber-physical production systems where the technologi…
Modular Contact-Free Conveyors for Handling Planar Fragile Objects
2017
Recent studies show that the handling of thin wafers in the photovoltaic industry can lead to unacceptable yields due to cell scratching and breaking. This paper presents the concept and design of a novel modular conveyor that is intended for handling planar fragile objects at a high speed without contact. Each element of the conveyor is a square block that is able to generate tilted air jets that lift and push the object in a single direction. Various handling functions can thus be achieved by the assembly of several blocks. To manage the complexity of assembling systems composed of hundreds of blocks, an automatized design methodology is proposed. This process gives the best topology of t…
Dynamic Modeling of Planar Multi-Link Flexible Manipulators
2021
A closed-form dynamic model of the planar multi-link flexible manipulator is presented. The assumed modes method is used with the Lagrangian formulation to obtain the dynamic equations of motion. Explicit equations of motion are derived for a three-link case assuming two modes of vibration for each link. The eigenvalue problem associated with the mass boundary conditions, which changes with the robot configuration and payload, is discussed. The time-domain simulation results and frequency-domain analysis of the dynamic model are presented to show the validity of the theoretical derivation.
Dynamic Modeling, Energy Analysis, and Path Planning of Spherical Robots on Uneven Terrains
2020
Spherical robots are generally comprised of a spherical shell and an internal actuation unit. These robots have a variety of applications ranging from search and rescue to agriculture. Although one of the main advantages of spherical robots is their capability to operate on uneven surfaces, energy analysis and path planning of such systems have been studied only for flat terrains. This work introduces a novel approach to evaluate the dynamic equations, energy consumption, and separation analysis of these robots rolling on uneven terrains. The presented dynamics modeling, separation analysis, and energy analysis allow us to implement path planning algorithms to find an optimal path. One of t…
An Input Observer-Based Stiffness Estimation Approach for Flexible Robot Joints
2020
This letter addresses the stiffness estimation problem for flexible robot joints, driven by variable stiffness actuators in antagonistic setups. Due to the difficulties of achieving consistent production of these actuators and the time-varying nature of their internal flexible elements, which are subject to plastic deformation over time, it is currently a challenge to precisely determine the total flexibility torque applied to a robot's joint and the corresponding joint stiffness. Herein, by considering the flexibility torque acting on each motor as an unknown signal and building upon Unknown Input Observer theory, a solution for electrically-driven actuators is proposed, which consists of …
Energy-based fluid–structure model of the vocal folds
2020
AbstractLumped elements models of vocal folds are relevant research tools that can enhance the understanding of the pathophysiology of many voice disorders. In this paper, we use the port-Hamiltonian framework to obtain an energy-based model for the fluid–structure interactions between the vocal folds and the airflow in the glottis. The vocal fold behavior is represented by a three-mass model and the airflow is described as a fluid with irrotational flow. The proposed approach allows to go beyond the usual quasi-steady one-dimensional flow assumption in lumped mass models. The simulation results show that the proposed energy-based model successfully reproduces the oscillations of the vocal …
A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders
2020
This paper concerns the stability issue of pump-controlled single-rod cylinders, known as mode switching. First, a review of the topic is provided. Thereafter, the most recently proposed solution for the elimination of mode switching is investigated and shown to result in unstable behavior under certain operating conditions. A theoretical analysis is provided demonstrating the underlying mechanisms of this behavior. Based on the analysis, a novel control strategy is proposed and investigated numerically. Proper operation and stability are demonstrated for a wide range of operating conditions, including situations under which the most recently proposed solution results in unstable behavior a…
Propulsion monitoring system for digitized ship management: Preliminary results from a case study
2020
Abstract The paradigm of Industry 4.0 a fundamental driver of innovation in marine industry, where the new digital era will see the development of smart cyber-ships equipped with advanced automation systems that will progressively evolve towards fully autonomous vessels. Although the journey towards such technological frontier has started, most companies operating in the maritime sector still appear un-prepared to face the future scenario. In the maritime sector, in fact, empirical models and oversimplified approaches are still largely employed for the management of fleet operations. There is thus the necessity of developing and providing operative models for digitized ship management, whic…
Energy demand reduction of aluminum alloys recycling through friction stir extrusion processes implementation
2019
Abstract Aluminum alloys are characterized by high-energy demands for primary production. Recycling is a well-documented strategy to lower the environmental impact of light alloys production. Despite that, conventional recycling processes are still energy-intensive with a low energy efficiency. Also, permanent material losses occur during remelting because of oxidation. Recently, several solid-state recycling approaches have been analyzed; in fact, by avoiding the remelting step both energy and material can be saved and, therefore, the embodied energy of secondary production can be substantially reduced. In this paper, the solid-state approach Friction Stir Extrusion (FSE) is analyzed for a…
Heat in Metal Cutting
2008
This chapter provides comprehensive knowledge regarding thermal effects during the cutting process with both uncoated and coated cutting tools. Main heat sources and flowing heat fluxes into the tool, chip and workpiece are characterized and quantified. The heat distribution models that allow the analytical prediction of heat partition between the tool and the chip are specified. They consider such thermal properties as specific heat, thermal conductivity and diffusivity, Peclet thermal number, and heat transmission ratio, all as functions of temperature. Finite element method and finite difference method simulations applied to the prediction of temperature fields are outlined for turning a…