A new vibration measurement procedure for on-line quality control of electronic devices

Abstract: In this paper the problem of experimentally testing the mechanical reliability of electronic components for quality control is approached. In general, many tests are performed on electronic devices (personal computers, power supply units, lamps, etc.), according to the relevant international standards (IEC), in order to verify their resistance to shock and vibrations, but these are mainly "go no-go" experiments, performed on few samples taken from the production batches. The idea here proposed is to improve the efficiency of these tests by using electro-optic techniques for the measurement of the vibration behaviour of the components under known excitation. This would allow the on-line testing of a high percentage of the production and would be useful to give important feedback to the design process. Scanning laser Doppler vibrometry seems to be a valuable solution for this problem, thanks to its capabilities of measuring several spatially-defined points on a vibrating object with reduced testing time for on-line application, with high sensitivity and accuracy, non-intrusivity and with any kind of excitation signal. Experimental tests are performed on a power supply: the results show the effectiveness of the proposed approach. The metrological problems connected with the on-line implementation are also discussed

A framework for comfort assessment in buildings and districts retrofit process

The retrofit design of buildings and districts cannot exclude the occupants’ perspective if comfortable and healthy conditions have to be obtained. For this reason, the NewTREND1 project developed a collaborative platform for the energy efficient buildings and districts retrofit that includes the users’ perspective. Three modules have been developed for thermal comfort, acoustic comfort and behavioural assessment. These modules are integrated into a Simulation and Design Hub that, after gathering data from on-site measurements, builds a simulation model of the district, calculates yearly results and exposes them to the design team through a dedicated District Information Model server and user interfaces. These modules perform deep investigations on the occupants’ sensation and behaviour, based on both measured and simulated datasets and provide comparisons of comfort performances, considering different retrofit scenarios and related uncertainties. In details, the thermal comfort module performs analysis according to both predictive and adaptive models, evaluates the variability around the design conditions together with sensitivity analysis that highlights which parameters are the most critical for the retrofit design. The acoustic module provides a complete tool to predict and assess the indoor acoustic comfort, taking into account the performance of building envelope and the impact of district noise. Finally, the behavioural module empowers the building energy simulation with co-simulation capabilities that reproduces the real occupants’ behaviours in relation to comfort conditions. The final goal of the framework is to support the decision-making process in selecting the optimal retrofit option that achieves the targeted energy efficiency without infringing the occupant’s expectation in terms of comfort and well-being

Measuring Occupants' Behaviour for Buildings' Dynamic Cosimulation

Measuring and identifying human behaviours are key aspects to support the simulation processes that have a significant role in buildings' (and cities') design and management. In fact, layout assessments and control strategies are deeply influenced by the prediction of building performance. However, the missing inclusion of the human component within the building-related processes leads to large discrepancies between actual and simulated outcomes. This paper presents a methodology for measuring specific human behaviours in buildings and developing human-in-the-loop design applied to retrofit and renovation interventions. The framework concerns the detailed building monitoring and the development of stochastic and data-driven behavioural models and their coupling within energy simulation software using a cosimulation approach. The methodology has been applied to a real case study to illustrate its applicability. A one-year monitoring has been carried out through a dedicated sensor network for the data recording and to identify the triggers of users' actions. Then, two stochastic behavioural models (i.e., one for predicting light switching and one for window opening) have been developed (using the measured data) and coupled within the IESVE simulation software. A simplified energy model of the case study has been created to test the behavioural approach. The outcomes highlight that the behavioural approach provides more accurate results than a standard one when compared to real profiles. The adoption of behavioural profiles leads to a reduction of the discrepancy with respect to real profiles up to 58% and 26% when simulating light switching and ventilation, respectively, in comparison to standard profiles. Using data-driven techniques to include the human component in the simulation processes would lead to better predictions both in terms of energy use and occupants' comfort sensations. These aspects can be also included in building control processes (e.g., building management systems) to enhance the environmental and system management

Plug-and-Play Solutions for Energy-Efficiency Deep Renovation of European Building Stock

none7siNinety percent of the existing building stock in Europe was built before 1990. These buildings are in urgent need for a significant improvement of energy-efficiency through renovation. State-of-the-art renovation solutions are available, but costly and lengthy renovation processes and incomprehensible technical complexities hinder the achievement of a wide impact at a European scale. This paper presents a research on Plug-and-Play (PnP) echnologies supported by Building Information Modelling (BIM) to provide affordable, interchangeable and quick-installation solutions to overcome the main barriers of building deep renovation.openSebastian, Rizal; Gralka, Anna; Olivadese, Rosamaria; Arnesano, Marco; Revel, Gian Marco; Hartmann, Timo; Gutsche, ChristophSebastian, Rizal; Gralka, Anna; Olivadese, Rosamaria; Arnesano, Marco; Revel, Gian Marco; Hartmann, Timo; Gutsche, Christop

IEQ measurement and assessment tools for Plug-and-Play deep renovation in buildings

This paper presents the approach developed for the monitoring and assessment of Indoor Environmental Quality (IEQ) in the whole deep renovation process aimed at reducing energy consumptions and improving comfort. The research was performed by the P2Endure project, that aims to provide scalable, adaptable and ready-to-implement prefabricated Plug-and-Play systems for deep renovation of building envelopes and technical systems. The idea is to use IEQ as one of the design criteria supporting the decision-making process, included into the holistic renovation process developed by P2Endure and called “4M: Mapping-Modelling- Making-Monitoring”. For this reason, a set of Key Performance Indicators (KPI) was selected, with the consequent measurement and calculation methodologies. The KPIs are collected and showed together with the analysis of the different IEQ dimensions (thermal and indoor air quality). The data collection has been investigated extensively, taking into account all possible data sources, measurements and surveys (e.g. special questionnaires for children in schools). In addition to traditional devices, the innovative Comfort Eye sensor is used in the proposed framework. This is a low-cost sensing system capable of measuring thermal comfort together with IAQ, applicable for permanent or periodic monitoring and with low disturbance for inhabitants. The overall procedure is presented, also in relation with the deep renovation process. Then, the application of the measurement and assessment tools in real demonstration cases is illustrated with initial results from the monitoring campaign

Stationary Wavelet Transform denoising in Pulsed Thermography: influence of camera resolution on defect detection

Denoising filters are widely used in image enhancement. However, they might induce severe blurring effects the lower is the resolution of the original image. When applied to a thermal image in Non-Destructive Testing (NDT), blurring could entail wrong estimation of defect boundaries and an overall reduction in defect detection performances. This contribution discusses the application of a wavelet-based denoising technique to a thermographic sequence obtained from a Pulsed Thermography testing, when using a high- resolution 1024x768 FPA infrared camera. Influence of denoising approach on data post- processed by Principal Component Analysis is discussed. Results indicate marked enhancement in defect detection, especially when compared to those obtained with a standard-resolution 320x240 FPA infrared camera

A Discrete-Continuous Method for Predicting Thermochemical Phenomena in a Cement Kiln and Supporting Indirect Monitoring

Thermochemical phenomena involved in cement kilns are still not well understood because of their complexity, besides technical difficulties in achieving direct measurements of critical process variables. This article addresses the problem of their comprehensive numerical prediction. The presented numerical model exploits Computational Fluid Dynamics and Finite Difference Method approaches for solving the gas domain and the rotating wall, respectively. The description of the thermochemical conversion and movement of the powder particles is addressed with a Lagrangian approach. Coupling between gas, particles and the rotating wall includes momentum, heat and mass transfer. Three-dimensional numerical predictions for a full-size cement kiln are presented and they show agreement with experimental data and benchmark literature. The quality and detail of the results are believed to provide a new insight into the functioning of a cement kiln. Attention is paid to the computational burden of the model and a methodology is presented for reducing the time-to-solution and paving the way for its exploitation in quasi-real-time, indirect monitoring

Stationary Wavelet Transform for denoising Pulsed Thermography data: optimization of wavelet parameters for enhancing defects detection

Innovative denoising techniques based on Stationary Wavelet Transform (SWT) have started being applied to Pulsed Thermography (PT) sequences, showing marked potentialities in improving defect detection. In this contribution, a SWT-based denoising procedure is performed on high and low resolution PT sequences. Samples under test are two composite panels with known defects. The denoising procedure undergoes an optimization step. An innovative criterion for selecting the optimal decomposition level in multi-scale SWT-based denoising is proposed. The approach is based on a comparison, in the wavelet domain, of the information content in the thermal image with noise propagated. The optimal wavelet basis is selected according to two performance indexes, respectively based on the probability distribution of the information content of the denoised frame, and on the Energy-to-Shannon Entropy ratio. After the optimization step, denoising is applied on the whole thermal sequence. The approximation coefficients at the optimal level are moved to the frequency domain, then low-pass filtered. Linear Minimum Mean Square Error (LMMSE) is applied to detail coefficients at the optimal level. Finally, Pulsed Phase Thermography (PPT) is performed. The performance of the optimized denoising method in improving the defect detection capability respect to the non-denoised case is quantified using the Contrast Noise Ratio (CNR) criterion

Development of a curtain wall prototype with dynamic behaviour (SmartSkin)

The paper presents a research project, derived from a collaboration between Universities, manufacturers and designers with international experience in curtain walls and HVAC systems. The research consisted in experimenting a technological solution for a building envelope with dynamic behaviour and high aesthetic value, which is able to respond to the influence of fixed and variable factors – internal and external – with respect to regulatory requirements and flexibility needs during the design and the operational phase. The goal is to reduce the embodied energy of the components, optimise the energy consumption during the use phase and limit the construction costs with the segmentation of the devices, the shrinkage of the floor height and the acceleration of the assembly process