Search results for "FAC"
showing 10 items of 36366 documents
Mobile manipulator performance measurement towards manufacturing assembly tasks
2016
Mobile manipulator performance measurement research is relatively minimal as compared to that of robot arms. Measurement methods, such as optical tracking systems, are useful for measuring the performance of mobile manipulators, although at a much higher relative cost as compared to artifacts. The concept of using test artifacts demonstrates to potential manufacturers and users of mobile manipulator systems that relatively low cost performance measurement methods exist. This paper discusses the concept of reconfigurable mobile manipulator artifacts that were designed and built. An artifact was then used through experimentation to measure the performance of a mobile manipulator to demonstrat…
Improving the Effectiveness in Research and Developments Department from Automotive Industry
2019
Abstract The scope of this paper is to propose a solution for decreasing the rework that has to be made inside a team, in a new offshore Research and Development department, mainly because of assumptions and lack of experience. This is based on learning and applying the lessons learned. First, it will be presented an order assignment in an offshore branch in the field of automotive software companies. From the concept, further on, the usual process that takes place is presented and the potential flaws are analyzed. The major problems identified are random allocation of the orders and assumptions that are made in the branch offices. After inspecting the steps of the process, a model of proce…
Towards criteria for sustainable process selection: On the modelling of pure subtractive versus additive/subtractive integrated manufacturing approac…
2017
Additive Manufacturing (AM) processes can be counted among the disruptive technologies that are capable of transforming conventional manufacturing routes. The ability to create complex geometries, the reduction in material scraps during manufacturing, and the light-weighting due to the think-additive redesign of the components represent the main points of strength of AM. However, for some applications (such as the production of metal components for the automotive and aerospace industries), the surface finishing and dimensional/geometrical part tolerancing that can be achieved via AM processes might not be adequate to satisfy the imposed product specifications, and finish machining operation…
Weld quality prediction in linear friction welding of AA6082-T6 through an integrated numerical tool
2016
Abstract A numerical and an experimental campaign were carried out with varying oscillation frequency and interface pressure. The local values of the main field variables at the contact interface between the specimens were predicted by a Lagrangian, implicit, thermo-mechanical FEM model and used as input of a dedicated Neural Network (NN). The NN, integrated in the FEM environment, was designed in order to calculate both a Boolean output, indicating the occurrence of welding, and a continuous output, indicating the quality of the obtained solid state weld. The analysis of the obtained results allowed three different levels of bonding quality, i.e., no weld, sound weld and excess of heat, to…
Robust control for high performance induction motor drives based on partial state-feedback linearization
2019
This paper deals with a robust input-output feedback linearization control technique for induction motors. Indeed, classic feedback linearization presents two main disadvantages: 1) the accuracy of the dynamic model; and 2) the corresponding correct knowledge of the model parameters. To address this issue, the linear controller has been substituted with a suitably controller designed to be robust to the variations of the main parameters of the induction motor, like stator and rotor resistances, and the three-phase magnetizing inductance. The proposed controller has been tested both in numerical simulation and experimentally on a suitably designed test setup. Moreover, it has been compared w…
Physical Load Among Construction Workers and Analysis with Objective Ergonomics Research Method
2016
There is growing number of work related musculoskeletal disorders among workers in construction industry. Employees in construction professions admit physical load and discomfort in various body parts after the work. Accordingly to Eurostat statistical data 60 % of total work related diseases are attributed to musculoskeletal disorders in Latvia. The aim of this study was to determine physical load of construction auxiliary workers and bricklayers using objective ergonomics research method HR monitoring and subjective ergonomic risk assessment methods. The research involved full time 8 auxiliary construction workers and 7 bricklayers. Analysis of the heart rate monitoring data proved that o…
Assessment of material models through simple machining tests
2008
The accuracy of the results obtained from FEM simulation of machining operations depends on the accuracy of input data. Among these, the flow stress data of the workpiece are extremely important together with the friction along the tool-chip interface. In this study, an identification procedure for the determination of material parameters that are used for the FEM simulation of machining processes is proposed. The procedure is based on the coupling of a numerical identification procedure and Arbitrarian Lagrangian Eulerian (ALE) Finite Element simulations of turning operations. An experimental campaign was developed in order to calibrate the model and to validate the procedure. The basic id…
Input-Output Feedback Linearization Control with On-line MRAS Based Inductor Resistance Estimation of Linear Induction Motors Including the Dynamic E…
2016
This paper proposes the theoretical framework and the consequent application of the input–output feedback linearization (FL) control technique to linear induction motors (LIMs). LIM, additionally to rotating induction motor, presents other strong nonlinearities caused by the dynamic end effects, leading to a space-vector dynamic model with time-varying inductance and resistance terms and a braking force term. This paper, starting from a recently developed dynamic model of the LIM taking into consideration its end effects, defines a FL technique suited for LIMs, since it inherently considers its dynamic end effects. Additionally, it proposes a technique for the on-line estimation of the indu…
A Pareto optimal design approach for simultaneous control of thinning and springback in stamping processes
2009
One of the most relevant research issues in automotive field is focused on the reduction of stamped parts weight also increasing their strength. In this way, a strong research effort is developed on high strength steels which are widely utilized and they require a proper springback control. Springback reduction in sheet metal forming is a typical goal to be pursued which is conflicting with thinning reduction for instance. Thus, such problems can be considered as multi-objective ones characterized by conflicting objectives. What is more, nowadays, a great interest would be focused on the availability of a cluster of possible optimal solutions instead of a single one, particularly in an indu…
Integration of gradient based and response surface methods to develop a cascade optimisation strategy for Y-shaped tube hydroforming process design
2010
International audience; In the last years a strong research effort was produced in order to develop and design new forming technologies able to overcome the typical drawbacks of traditional forming operations. Among such new technologies, hydroforming proved to be one of the most promising. The design of tube hydroforming operations is mainly aimed to prevent bursting or buckling occurrence and such issues can be pursued only if a proper control of both material feeding history and internal pressure path during the process is performed.In this paper, a proper optimisation strategy was developed on Y-shaped tube hydroforming process which is characterized by a quite complex process mechanics…