1,721,015 research outputs found
Concurrent Multi-domain Modelling and Simulation for Energy-Efficient Mechatronic Systems
No full textA graph-based approach and an interactive tool for preliminary digital prototyping
No full textDesign process is usually based on past experiences and best practises which compose the company know-how. The challenge is to identify common patterns in the design solutions generated for different design problems. The present paper focuses on the identification of product patterns by using a graph-based approach. It deals with the designing of automotive gearboxes and with the development of an approach and a software tool aimed to support preliminary design and CAD modelling activities in gearbox designing. The approach is applied to two different architectures of manual transverse gearboxes characterized by two and three shafts. It aims at the identification of common design features through the detection of the directed graphs matching. A Matlab software tool for gearbox preliminary design is implemented according to the detected common features. The proposed approach and the developed software tool provide an effective way to keep and re-use company know-how, especially in the context of large automotive companies
La decorazione dei manoscritti pre-desideriani nei fondi della Biblioteca Apostolica Vaticana
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Tolerance Prediction for Determinate Assembly Approach in Aeronautical Field
No full textThe optimization of the aeronautical assembly lines is one of the most challenging tasks in development of a new aircraft. To date the Aeronautical companies are founding project related to the optimization of the manufacturing processes, impacting on the reduction of the non-recurring costs. The work presented focuses on methods for the implementation of the determinate assembly approach in the case of manufacturing of aeronautical structures. The methods are based on the prediction of the coupling tolerances between airframe components in order to reduce the numbers of the features to be manufactured in assembly. All that to lead to a reduction of the non-recurring costs
A Sensor Data Fusion-Based Locating Method for Reverse Engineering Scanning Systems
No full textThe measurement of geometric deviations within large-size products is a challenging topic. One of the most applied technique compares the nominal product with the digitalization of real product obtained by a reverse engineering process. Digitalization of big geometric models is usually performed by means of multiple acquisitions from different scanning locations. Therefore, digitalization needs to correctly place the acquired point clouds in 3D digital environment. For this purpose, it is very important identifying the exact scanning location in order to correctly realign point clouds and generate an accurate 3D CAD model.The present paper faces the locating problem of a handling device for reverse engineering scanning systems. It proposes a locating method by using sensor data fusion based on Kalman filter, implemented in Matlab environment by using a low-cost equipment
Battery Thermal Management Systems: A Case Study on Li-NMC storage systems for electric vehicles
No full textThis paper deals with the thermal management of Li-NMC battery packs for their use in electric vehicle applications. In particular, starting from a literature analysis, different kinds of battery thermal management systems (BTMSs) are evaluated and compared, in terms of their main advantages and drawbacks related to cost and complexity. A specific case study focused on a BTMS, based on forced air cooling, for a Li-NMC battery pack is then proposed, with the application of a simple temperature control strategy. Numerical evaluations are carried out in simulation environment by means of a Matlab/Simulink storage cell electro-thermal model, which has been parametrized and validated through experimental procedures. Simulation results, obtained in different operative conditions, highlight the positive effects of using BTMS with particular reference to high power demanding battery charging and discharging operations
Design approach for electric vehicle battery packs based on experimentally tested multi-domain models
No full textThis work proposes a multi-domain modelling methodology to support the design of new battery packs for automotive applications. The methodology allows electro-thermal evaluation of different spatial arrangements of the storage cells by exploiting the implementation of numerical and geometrical battery pack models. Concerning the case study on Li-NMC battery technology, the study has completed the electro-thermal characterization of the storage cells starting from the collected experimental data, considering both the thermal interactions among cells and the effects of the state of health. This work also investigates the effects of forced air-cooling systems focusing on battery pack hot spots and temperature distributions. The results show a good fit between numerical models and data obtained from single-cell experiments. The virtual linking of geometric and numerical lumped-parameter models proved to be effective in rapid battery pack prototyping for electric vehicles, helping designers and manufacturers find suitable solutions for specific automotive applications
Rapid Response Diagnosis of Multi-stage Assembly Process with Compliant non-ideal Parts using Self-evolving Measurement System
No full textThis paper introduces the novel concept of self-evolving measurement system with the aim of rapidly identifying and localising defect patterns in multi-stage assembly systems with compliant non-ideal parts. This allows to enhance the level of diagnosability which cannot be achieved using fixed and static pre-determined measurement systems. The proposed methodology helps to identify and select new measurement points to increase the likelihood of isolating root causes of defects. This happens by automatically classifying defect patterns and associating them to critical key control characteristics. The methodology integrates supervised machine learning tools with first principle engineering simulations. It is based on the principle of pattern similarity, taking into account data generated by the self-evolving measurement system. The methodology is demonstrated and validated using the results of an automotive door assembly system
- …
