Search results for "Drive"
showing 10 items of 543 documents
A Note on the Shear Influence on Belt Drive Mechanics
2007
Abstract Belt drives work often with short center distances and very different wrap arcs so that high adherence characteristics are required at the belt-pulley contact. In addition, the belt flexural stiffness reduces the contact width, but this decrease may be compensated in part by the belt softening due to the shear compliance.
A Simple Model for the Axial Thrust in V-Belt Drives
1996
Simple formulas can relate axial thrust and torque of rubber V-belt drives, taking into consideration the radial penetration of the belt.
Design optimization on the drive train of a light-weight robotic arm
2011
A drive train optimization method for design of light-weight robots is proposed. Optimal selections of motors and gearboxes from a limited catalog of commercially available components are done simultaneously for all joints of a robotic arm. Characteristics of the motor and gearbox, including gear ratio, gear inertia, motor inertia, and gear efficiency, are considered in the drive train modeling. A co-simulation method is developed for dynamic simulation of the arm. A design example is included to demonstrate the proposed design optimization method.
Identification and Experimental Validation of an Induction Motor Thermal Model for Improved Drivetrain Design
2017
The ability of an electric powertrain to perform according to mechanical specifications is equally important as assessing its thermal protection limits, which are affected by its electrical and thermal properties. Although rated parameters (such as power, torque, etc.) are easily accessible in catalogs of equipment producers, more specific properties like mass/length of copper winding, heat dissipation factor, etc., are not available to customers. Therefore, an effective selection of drivetrain components is limited due to the lack of sufficient data and the need to consult critical design decisions with suppliers. To overcome this limitation, we propose a method to estimate the temperature…
Motion control of medium size CNC machine-tools-A hands-on approach
2012
This paperwork presents an integrated approach based upon simulation and experimental work for reducing the positioning errors of a small to medium size CNC machine-tools. The approach is intended to be used at the shop-floor level and therefore it is based upon a straight-forward model of the feed drive. The model was particularized with specific data from a CNC milling machine and simulation techniques were used to predict the behavior of the system. Only the control parameters of the feed drive which may be altered by the user, without modifying the structure of the CNC controller were taken into consideration and tuned. Simulation results and experimental data gathered before and after …
Hand-Held texting is less distracting than texting with the phone in a holder: anyway, don't do it
2015
We studied the effects of texting while driving and the effects of mobile phone position (hand-held, holder) on drivers' lane-keeping performance, experienced workload, and in-car glance durations in a motion-platform driving simulator with 24 participants. Overall, we found the known negative effects of texting on lane-keeping performance, workload, and visual attention on road, suggesting that texting on the road in any manner is not risk-free. As a novel finding, we found that hand-held texting led to fewer lane-keeping errors and shorter total glance times off road compared to texting with the phone in a holder. We suggest the explanation is that the drivers had considerably more experi…
How Circular Dichroism in Time- and Angle-Resolved Photoemission Can Be Used to Spectroscopically Detect Transient Topological States in Graphene
2020
Pumping graphene with circularly polarized light is the archetype of light-tailoring topological bands. Realizing the induced Floquet-Chern-insulator state and demonstrating clear experimental evidence for its topological nature has been a challenge, and it has become clear that scattering effects play a crucial role. We tackle this gap between theory and experiment by employing microscopic quantum kinetic calculations including realistic electron-electron and electron-phonon scattering. Our theory provides a direct link to the build up of the Floquet-Chern-insulator state in light-driven graphene and its detection in time- and angle-resolved photoemission spectroscopy (ARPES). This approac…
Closed-loop bandwidth impact on MVSA for rotor broken bar diagnosis in IRFOC double squirrel cage induction motor drives
2013
This paper investigates the detectability of rotor broken bars in indirect rotor flux oriented control (IRFOC) for variable speed double cage induction motor drives, using vibration signature analysis techniques. The Impact of the closed loop control system cannot be neglected when the detection of rotor asymmetries in the machine is based on the signature analysis of electrical or mechanical variables. Therefore, the investigation of rotor fault components for different bandwidths of closed-loop regulators is necessary to evaluate its relevance in the above listed variables. This paper investigates the impact of the control system on relevance of the fault components computed from axial an…
No Entrepreneurship without Opportunity: The Intersection of Return Migration Research and Entrepreneurship Literature
2019
Abstract The article proposes a theoretical discussion at the crossroads of the return migration scholarship with the entrepreneurship research. Its main goal is to build an analytical framework in which entrepreneurial experiences of international return migrants are conceptualized. The fertile theoretical legacy within the study of entrepreneurship along with an idealized view of the positive effects of migration constitute essential premises for understanding the biased outputs of the empirical studies of entrepreneurship upon return to the origin country. Firstly, the article draws on the main lines of theorising opportunities within the Weberian and Schumpeterian theoretical traditions…
The Analysis of the Factors Influencing the Severity of Bicyclist Injury in Bicyclist-Vehicle Crashes
2021
Transportation and technological development have for centuries strongly influenced the shaping of urbanized areas. On one hand, it undoubtedly brings many benefits to their residents. However, also has a negative impact on urban areas and their surroundings. Many transportation and technological solutions lead, for example, to increased levels of pollution, noise, excessive energy use, as well as to traffic accidents in cities. So, it is important to safe urban development and sustainability in all city aspects as well as in the area of road transport safety. Due to the long-term policy of sustainable transport development, cycling is promoted, which contributes to the increase in the numb…