Search results for "09"
showing 10 items of 12776 documents
Opportunities for the Use of Business Data Analysis Technologies
2016
Abstract The paper analyses the business data analysis technologies, provides their classification and considers relevant terminology. The feasibility of business data analysis technologies handling big data sources is overviewed. The paper shows the results of examination of the online big data source analytics technologies, data mining and predictive modelling technologies and their trends.
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…
Modelling and Simulation of Machining Processes and Operations
2008
This chapter provides the state-of-the-art knowledge engineering and modelling techniques applied in manufacturing/machining and overviews future trends observed at a global scale. Modelling methods for machining processes and operations are classified. The chapter also highlights the multiple tasks of modelling and simulation in modern machining/manufacturing systems. The most popular techniques of numerical simulation including finite difference method and finite element method (FEM) related to mechanical and thermal problems arising in machining processes are described. Practical examples of FE models of various metal cutting operations and their importance in modern manufacturing are pr…
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…
A unified observer for robust sensorless control of DC–DC converters
2017
Abstract Due to the large variety of converters' configurations, many different sensorless controllers are available in the literature, each one suited for a particular converter. The need for different configurations, especially on the same power supply, make it clear the advantage of having a shared control algorithm. This paper presents a unified nonlinear robust current observer for buck, boost and buck–boost converters in synchronous and asynchronous configurations. The unified observer speeds up the design, tuning and the implementation, and requires a memory cheaper code, easier to certify. Simulation and experimental results are presented to validate the approach in different scenar…
Robust Composite Nonlinear Feedback Path-Following Control for Independently Actuated Autonomous Vehicles With Differential Steering
2016
This paper investigates utilizing the front-wheel differential drive-assisted steering (DDAS) to achieve the path-following control for independently actuated (IA) electric autonomous ground vehicles (AGVs), in the case of the complete failure of the active front-wheel steering system. DDAS, which is generated by the differential torque between the left and right wheels of IA electric vehicles, can be utilized to actuate the front wheels as the sole steering power when the regular steering system fails, and thus avoids dangerous consequences for AGVs. As an inherent emergency measure and an active safety control method for the steering system of electric vehicles, DDAS strategy is a valuabl…
Direct analysis of power-split CVTs: A unified method
2018
Abstract This paper provides a fast kinematic analysis method for compound power-split CVTs, which consents to identify their functional parameters. Such parameters permit the assessment of power flows, torques and efficiency, and the design of equivalent transmissions by the use of a recently published mathematical model. The same method can easily address either simpler or more complex transmissions by mean of kinematic equivalent parameters, without the need to arrange separate systems of equations. As a case study, we performed the kinematic analysis of the “Voltec” multi-mode GM transmission.
Vibration reduction on city buses: Determination of optimal position of engine mounts
2010
International audience; This study is composed of three essential parts. The first part describes an indirect semi-experimental method which is used to reconstruct the excitation force of an operating diesel engine from the acceleration data measured at the mounting points. These internal forces can not be directly measured with force sensors; they have to be derived from the dynamic deformation of the engine support, so a theoretical analysis is carried out to derive the equations for the force re-construction.The second part deals with prevention of low frequency vibration of the powertrain from spreading to the rest of the vehicle. Three uncoupling techniques are used to minimize these v…